Musculoskeletal conditions affect hundreds of millions of people around the world and this figure is expected to increase sharply due to the predicted doubling of the population over 50 by the year 2020 (“The Global Burden of Disease. A Comprehensive Assessment of Mortality and Disability from Diseases, Injuries, and Risk Factors in 1990 and Projected to 2020”, C. J. L. Murray and A. D. Lopez (Eds.), 1996, Harvard University Press: Cambridge, Mass.). Musculoskeletal conditions give rise to enormous healthcare expenditures and loss of economic productivity, and therefore have a huge impact on society. In the U.S. alone, musculoskeletal conditions were estimated to have cost $214 billion in 1995 (A. Praemer et al., “Musculoskeletal Conditions in the United States”, 2nd Ed., 1999, American Academy of Orthopaedic Surgeons Rosemont, Ill.). While there are many types of musculoskeletal conditions, osteoarthritis is one of the most common chronic musculoskeletal disorders encountered by physicians throughout the world.
Osteoarthritis (OA) is a non-inflammatory joint disease, which is characterized by the breakdown of joint cartilage. It may affect one or more joints in the body, including those of the fingers, neck, shoulder, hips, knees, lower spine region, and feet. OA can cause pain and severely impair mobility and lower extremity function (E. Bagge et al., Age Ageing, 1992, 21: 160-167; D. Hamerman, Ann. Rheum. Dis., 1995, 54: 82-85; J. Jordan et al., J. Rheumatol., 1997, 24: 1344-1349; S. M. Ling and J. M. Bathon, J. Am. Geriatr. Soc., 1998, 46: 216-225), which can lead to disability and difficulty maintaining independence (A. A. Guccione et al., Am. J. Public Health, 1994, 84: 351-358; M. A Gignac et al., J. Gerontol. B: Psychol. Sci. Soc. Sci., 2000, 55: 362-372; M. C. Corti and C. Rignon, Aging Clin. Exp. Res., 2003, 15: 359-363).
Currently, diagnosis of OA is typically based upon radiological examination as well as clinical observations including localized tenderness, use-related pain, bony or soft tissue swelling, joint instability, limited joint function, muscle spasm, and crepitus (i.e., cracking or grinding sensation). While the diagnosis of OA is often suggested on physical examination, radiographic evaluation is generally used to confirm the diagnosis or assess the severity of the disease. The radiographic hallmarks of OA include nonuniform joint space loss, osteophyte formation, cyst formation, and subchondral sclerosis. While these characteristic features are generally present in X-ray images of “severe” or “late” OA, patients with “early” OA may not show radiographic evidence of bony changes, joint space narrowing and/or osteophytosis, making the diagnosis unclear or difficult to establish.
The present invention relates to the use of protein expression profiles with clinical relevance to osteoarthritis. In particular, the invention provides the identity of proteins, whose expression is correlated with osteoarthritis (OA) and/or with different phases of advancement of the disease. These protein expression profiles may be applied to the diagnosis and staging of disease useful for prognostic purposes in OA. Compared to existing methods of diagnosis, the protein expression profiles disclosed herein constitute a more robust signature of OA and OA progression, and provide a more reliable basis for the selection of appropriate therapeutic regimens. The invention also relates to the screening of drugs that target these biomarkers, in particular for the development of new therapeutics for the treatment of OA.
In general, the invention involves the use of expression profiles of the marker proteins listed in attached Tables 1-6 for diagnosing osteoarthritis. More specifically, the present invention provides methods for distinguishing between stages of osteoarthritis. Methods are provided that comprise steps of: providing a biological sample obtained from a subject to be tested; determining, in the biological sample, the level of expression of a one or more of polypeptides selected from the group consisting of proteins presented in Tables 1-6.
In one embodiment, the proteins can comprise at least one of alpha-2-macroglobulin precursor, fibronectin precursor, Chain B structure of complement C3b, C9 complement protein, coagulation factor II precursor, alpha-1-antichymotrypsin, complement component C3, complement factor H, inter-alpha-trypsin heavy chain H1 precursor, complement factor H isoform a precursor, gelsolin isoform a precursor, ceruloplasmin, inter-alpha-trypsin inhibitor heavy chain H4 precursor, phosphatidylinositol-glycan-specific phospholipase D1 precursor, inter-alpha-trypsin inhibitor family heavy chain-related protein, glycosylphosphatidylinositol specific phosphatase D1, complement component C6 precursor peptide, complement factor B, pre-pro-alpha(I) collagen, SERPIN2 protein, gp-180-carboxypeptidase D-like enzyme, Fibulin-1 isoform D precursor, plasminogen, HGF activator preproprotein, afamin precursor, Vitamin K-dependent protein, complement component 1 s subcomponent, inter-alpha-trypsin inhibitor, ASPIC, complement component 3 precursor, plasma kallikrein precursor, annexin A2 isoform 2, glucosamine(N-acetyl)-6-sulfatase precursor, (cystic fibrosis antigen), ezrin (p81) (cytovillin) (villin-2), S100 Calcium binding protein A9, coagulation factor XIII A chain precursor, peptidoglycan recognition protein L precursor, complement component 4 binding protein, inter-alpha-trypsin inhibitor heavy chain H1 precursor, fibrinogen gamma chain, Ig mu chain precursor, phospholipase D3 isoform, moesin, alpha-2-antiplasmin precursor, kininogen, thrombin inhibitor, Chain A antithrombin III, L-plastin, complement component 1, alpha-1-B-glycoprotein, hemopexin precursor, complement component C4A, apolipoprotein A-IV precursor, serum paraoxonase/arylesterase, preprohaptoglobulin, COMP, serpin peptidase inhibitor clade I, follistatin-like 1 precursor, complement factor H-related protein 1 precursor, Chain A Crystal Structure of Lipid-Free human Apolipoprotein A-1, phospholipase D3 isoform 2, Chain E Structure of human transferring receptor-transferrin complex, complement component C3, analogs and fragments thereof; and any combination thereof.
In other embodiments, the proteins can comprise at least one of alpha-2-macroglobulin precursor, fibronectin precursor, Chain B structure of complement C3b, C9 complement protein, coagulation factor II precursor, alpha-1-antichymotrypsin, complement factor H, inter-alpha-trypsin heavy chain H1 precursor, complement factor H isoform a precursor, gelsolin isoform a precursor, inter-alpha-trypsin inhibitor heavy chain H4 precursor, phosphatidylinositol-glycan-specific phospholipase D1 precursor, inter-alpha-trypsin inhibitor family heavy chain-related protein, glycosylphosphatidylinositol specific phosphatase D1, complement component C6 precursor peptide, complement factor B, pre-pro-alpha(I) collagen, SERPIN2 protein, gp-180-carboxypeptidase D-like enzyme, Fibulin-1 isoform D precursor, plasminogen, HGF activator preproprotein, afamin precursor, Vitamin K-dependent protein, complement component 1 s subcomponent, inter-alpha-trypsin inhibitor, ASPIC, complement component 3 precursor, plasma kallikrein precursor, annexin A2 isoform 2, glucosamine(N-acetyl)-6-sulfatase precursor, (cystic fibrosis antigen), ezrin (p81) (cytovillin) (villin-2), 5100 Calcium binding protein A9, coagulation factor XIII A chain precursor, peptidoglycan recognition protein L precursor, complement component 4 binding protein, inter-alpha-trypsin inhibitor heavy chain H1 precursor, fibrinogen gamma chain, Ig mu chain precursor, phospholipase D3 isoform, moesin, alpha-2-antiplasmin precursor, kininogen, thrombin inhibitor, Chain A antithrombin III, L-plastin, complement component 1, alpha-1-B-glycoprotein, hemopexin precursor, complement component C4A, apolipoprotein A-IV precursor, serum paraoxonase/arylesterase, preprohaptoglobulin, COMP, serpin peptidase inhibitor clade I, follistatin-like 1 precursor, complement factor H-related protein 1 precursor, Chain A Crystal Structure of Lipid-Free human Apolipoprotein A-1, phospholipase D3 isoform 2, Chain E Structure of human transferring receptor-transferrin complex, complement component C3, analogs and fragments thereof; and any combination thereof.
In still other embodiments, the proteins can comprise at least one of fibronectin precursor, complement component C3, alpha-2-macroglobulin precursor, Chain B Structure of Complement C3b, complement factor H, fibronectin 1 isoform 3 preproprotein, alpha-2-macroglobulin, collagen type IV alpha 1, alph 2 type IV collagen preprotein, inter-alpha-trypsin inhibitor, C-terminal inter-alpha trypsin inhibitor, ceruloplasmin, phosphatidylinositol-glycan-specific phospholipase D1, afamin precursor, complement component 6 isoform CRA_b, inter-alpha-trypsin inhibitor heavy chain-related protein, Chain A Crystal Structure of human Galectin-7, serum albumin, COMP, ALB protein, gelsolin isoform a precursor, complement factor B, fibulin-1 isoform D precursor, inter-alpha-globulin inhibitor H4, valosin-containing protein, Vitamin D-binding protein precursor, complement component 2 precursor, annexin A2, Annexin A2 isoform 2, homerin precursor, complement component 1 s subcomponent, ASPIC, Vitamin K-dependent protein, plasma kallikrein precursor, S100 calcium-binding protein A9, Protein S100-A7 (psoriasin), coagulation factor XIII, B Chain Alpha-Ferrous-Carbonmonoxy, coagulation factor II precursor, insulin-like growth factor binding protein acid labile subunit, histidine-rich glycoprotein precursor, phospholipid transfer protein isoform a precursor, antithrombin III, glucosamine(N-acetyl)-6-sulfatase precursor, coagulation factor XIII B chain, vitronectin, biotinidase precursor, acid labile subunit, alpha-1-B-glycoprotein, thrombin inhibitor, C9 complement protein, Coagulation factor XIII B chain precursor, hemopexin precursor, vanin 1 precursor, extracellular matrix protein 1 isoform precursor, histidine-rich glycoprotein, dopamine beta-hydroxylase precursor, peptidoglycan recognition protein L precursor, Chain A Crystal Structure of Native Heparin Cofactor Ii, fibrinogen gamma chain, inter-alpha (globulin) inhibitor H1, alpha-2-antiplasmin precursor, vitronectin precursor, Vitamin K-dependent protein S precursor, complement component 9, GRP78, analogs and fragments thereof; and any combination thereof.
In further embodiments, the proteins can comprise at least one of fibronectin precursor, alpha-2-macroglobulin precursor, Chain B Structure of Complement C3b, complement factor H, fibronectin 1 isoform 3 preproprotein, collagen type IV alpha 1, alph 2 type IV collagen preprotein, inter-alpha-trypsin inhibitor, C-terminal inter-alpha trypsin inhibitor, phosphatidylinositol-glycan-specific phospholipase D1, afamin precursor, complement component 6 isoform CRA_b, inter-alpha-trypsin inhibitor heavy chain-related protein, Chain A Crystal Structure of human Galectin-7, COMP, ALB protein, gelsolin isoform a precursor, complement factor B, fibulin-1 isoform D precursor, valosin-containing protein, Vitamin D-binding protein precursor, complement component 2 precursor, annexin A2, Annexin A2 isoform 2, homerin precursor, complement component 1 s subcomponent, ASPIC, Vitamin K-dependent protein, plasma kallikrein precursor, S100 calcium-binding protein A9, Protein S100-A7 (psoriasin), coagulation factor XIII, B Chain Alpha-Ferrous-Carbonmonoxy, coagulation factor II precursor, insulin-like growth factor binding protein acid labile subunit, histidine-rich glycoprotein precursor, phospholipid transfer protein isoform a precursor, antithrombin III, glucosamine(N-acetyl)-6-sulfatase precursor, coagulation factor XIII B chain, vitronectin, biotinidase precursor, acid labile subunit, alpha-1-B-glycoprotein, thrombin inhibitor, C9 complement protein, Coagulation factor XIII B chain precursor, hemopexin precursor, vanin 1 precursor, extracellular matrix protein 1 isoform precursor, histidine-rich glycoprotein, dopamine beta-hydroxylase precursor, peptidoglycan recognition protein L precursor, Chain A Crystal Structure of Native Heparin Cofactor Ii, fibrinogen gamma chain, inter-alpha (globulin) inhibitor H1, alpha-2-antiplasmin precursor, vitronectin precursor, Vitamin K-dependent protein S precursor, complement component 9, GRP78, analogs and fragments thereof; and any combination thereof.
In still other embodiments, the proteins can comprise at least one of alpha-2-macroglobulin precursor, fibronectin precursor, Chain B structure of complement C3b, C9 complement protein, coagulation factor II precursor, alpha-1-antichymotrypsin, complement component C3, complement factor H, inter-alpha-trypsin heavy chain H1 precursor, complement factor H isoform a precursor, gelsolin isoform a precursor, ceruloplasmin, inter-alpha-trypsin inhibitor heavy chain H4 precursor, phosphatidylinositol-glycan-specific phospholipase D1 precursor, inter-alpha-trypsin inhibitor family heavy chain-related protein, glycosylphosphatidylinositol specific phosphatase D1, complement component C6 precursor peptide, complement factor B, pre-pro-alpha(I) collagen, SERPIN2 protein, gp-180-carboxypeptidase D-like enzyme, Fibulin-1 isoform D precursor, plasminogen, HGF activator preproprotein, afamin precursor, Vitamin K-dependent protein, complement component 1 s subcomponent, inter-alpha-trypsin inhibitor, ASPIC, complement component 3 precursor, plasma kallikrein precursor, annexin A2 isoform 2, glucosamine(N-acetyl)-6-sulfatase precursor, (cystic fibrosis antigen), ezrin (p81) (cytovillin) (villin-2), S100 Calcium binding protein A9, coagulation factor XIII A chain precursor, peptidoglycan recognition protein L precursor, complement component 4 binding protein, inter-alpha-trypsin inhibitor heavy chain H1 precursor, fibrinogen gamma chain, Ig mu chain precursor, phospholipase D3 isoform, moesin, alpha-2-antiplasmin precursor, kininogen, thrombin inhibitor, Chain A antithrombin III, L-plastin, complement component 1, alpha-1-B-glycoprotein, hemopexin precursor, complement component C4A, apolipoprotein A-IV precursor, serum paraoxonase/arylesterase, preprohaptoglobulin, COMP, serpin peptidase inhibitor clade I, follistatin-like 1 precursor, complement factor H-related protein 1 precursor, Chain A Crystal Structure of Lipid-Free human Apolipoprotein A-1, phospholipase D3 isoform 2, Chain E Structure of human transferring receptor-transferrin complex, complement component C3, fibronectin 1 isoform 3 preproprotein, alpha-2-macroglobulin, collagen type IV alpha 1, C-terminal inter-alpha trypsin inhibitor, phosphatidylinositol-glycan-specific phospholipase D1, complement component 6 isoform CRA_b, Chain A Crystal Structure of human Galectin-7, serum albumin, ALB protein, inter-alpha-globulin inhibitor H4, valosin-containing protein, Vitamin D-binding protein precursor, complement component 2 precursor, annexin A2, homerin precursor, Protein S100-A7 (psoriasin), coagulation factor XIII, B Chain Alpha-Ferrous-Carbonmonoxy, insulin-like growth factor binding protein acid labile, histidine-rich glycoprotein precursor, phospholipid transfer protein isoform a precursor, coagulation factor XIII B chain, vitronectin, biotinidase precursor, alpha-1-B-glycoprotein, Coagulation factor XIII B chain precursor, vanin 1 precursor, extracellular matrix protein 1 isoform precursor, histidine-rich glycoprotein, dopamine beta-hydroxylase precursor, Chain A Crystal Structure of Native Heparin Cofactor Ii, inter-alpha (globulin) inhibitor H1, vitronectin precursor, Vitamin K-dependent protein S precursor, GRP78, analogs and fragments thereof; and any combination thereof.
In other embodiments, the proteins can comprise at least one of alpha-2-macroglobulin precursor, fibronectin precursor, Chain B structure of complement C3b, C9 complement protein, coagulation factor II precursor, alpha-1-antichymotrypsin, complement factor H, inter-alpha-trypsin heavy chain H1 precursor, complement factor H isoform a precursor, gelsolin isoform a precursor, inter-alpha-trypsin inhibitor heavy chain H4 precursor, phosphatidylinositol-glycan-specific phospholipase D1 precursor, inter-alpha-trypsin inhibitor family heavy chain-related protein, glycosylphosphatidylinositol specific phosphatase D1, complement component C6 precursor peptide, complement factor B, pre-pro-alpha(I) collagen, SERPIN2 protein, gp-180-carboxypeptidase D-like enzyme, Fibulin-1 isoform D precursor, plasminogen, HGF activator preproprotein, afamin precursor, Vitamin K-dependent protein, complement component 1 s subcomponent, inter-alpha-trypsin inhibitor, ASPIC, complement component 3 precursor, plasma kallikrein precursor, annexin A2 isoform 2, glucosamine(N-acetyl)-6-sulfatase precursor, (cystic fibrosis antigen), ezrin (p81) (cytovillin) (villin-2), 5100 Calcium binding protein A9, coagulation factor XIII A chain precursor, peptidoglycan recognition protein L precursor, complement component 4 binding protein, inter-alpha-trypsin inhibitor heavy chain H1 precursor, fibrinogen gamma chain, Ig mu chain precursor, phospholipase D3 isoform, moesin, alpha-2-antiplasmin precursor, kininogen, thrombin inhibitor, Chain A antithrombin III, L-plastin, complement component 1, alpha-1-B-glycoprotein, hemopexin precursor, complement component C4A, apolipoprotein A-IV precursor, serum paraoxonase/arylesterase, preprohaptoglobulin, COMP, serpin peptidase inhibitor clade I, follistatin-like 1 precursor, complement factor H-related protein 1 precursor, Chain A Crystal Structure of Lipid-Free human Apolipoprotein A-1, phospholipase D3 isoform 2, Chain E Structure of human transferring receptor-transferrin complex, complement component C3, fibronectin 1 isoform 3 preproprotein, collagen type IV alpha 1, C-terminal inter-alpha trypsin inhibitor, phosphatidylinositol-glycan-specific phospholipase D1, complement component 6 isoform CRA_b, Chain A Crystal Structure of human Galectin-7, ALB protein, valosin-containing protein, Vitamin D-binding protein precursor, complement component 2 precursor, annexin A2, homerin precursor, Protein S100-A7 (psoriasin), coagulation factor XIII, B Chain Alpha-Ferrous-Carbonmonoxy, insulin-like growth factor binding protein acid labile, histidine-rich glycoprotein precursor, phospholipid transfer protein isoform a precursor, coagulation factor XIII B chain, vitronectin, biotinidase precursor, alpha-1-B-glycoprotein, Coagulation factor XIII B chain precursor, vanin 1 precursor, extracellular matrix protein 1 isoform precursor, histidine-rich glycoprotein, dopamine beta-hydroxylase precursor, Chain A Crystal Structure of Native Heparin Cofactor Ii, inter-alpha (globulin) inhibitor H1, vitronectin precursor, Vitamin K-dependent protein S precursor, GRP78, analogs and fragments thereof; and any combination thereof.
In certain embodiments, providing an osteoarthritis diagnosis to the subject comprises comparing the test protein expression profile to a control protein expression, wherein the difference between the test protein expression profile and the control protein expression profile is indicative of early or late stage osteoarthritis in the subject; and based on the comparison, identifying osteoarthritis in the subject as early stage or late stage osteoarthritis.
In certain embodiments, the control protein expression profile is an early stage osteoarthritis expression profile, and the difference is indicative of late stage osteoarthritis. In such embodiments, the difference may be selected from the group consisting of an increase or decrease in the level of expression of one or more proteins selected from the group consisting of alpha-2-macroglobulin precursor, fibronectin precursor, Chain B structure of complement C3b, C9 complement protein, coagulation factor II precursor, alpha-1-antichymotrypsin, complement factor H, inter-alpha-trypsin heavy chain H1 precursor, complement factor H isoform a precursor, gelsolin isoform a precursor, inter-alpha-trypsin inhibitor heavy chain H4 precursor, phosphatidylinositol-glycan-specific phospholipase D1 precursor, inter-alpha-trypsin inhibitor family heavy chain-related protein, glycosylphosphatidylinositol specific phosphatase D1, complement component C6 precursor peptide, complement factor B, pre-pro-alpha(I) collagen, SERPIN2 protein, gp-180-carboxypeptidase D-like enzyme, Fibulin-1 isoform D precursor, plasminogen, HGF activator preproprotein, afamin precursor, Vitamin K-dependent protein, complement component 1 s subcomponent, inter-alpha-trypsin inhibitor, ASPIC, complement component 3 precursor, plasma kallikrein precursor, annexin A2 isoform 2, glucosamine(N-acetyl)-6-sulfatase precursor, (cystic fibrosis antigen), ezrin (p81) (cytovillin) (villin-2), S100 Calcium binding protein A9, coagulation factor XIII A chain precursor, peptidoglycan recognition protein L precursor, complement component 4 binding protein, inter-alpha-trypsin inhibitor heavy chain H1 precursor, fibrinogen gamma chain, Ig mu chain precursor, phospholipase D3 isoform, moesin, alpha-2-antiplasmin precursor, kininogen, thrombin inhibitor, Chain A antithrombin III, L-plastin, complement component 1, alpha-1-B-glycoprotein, hemopexin precursor, complement component C4A, apolipoprotein A-IV precursor, serum paraoxonase/arylesterase, preprohaptoglobulin, COMP, serpin peptidase inhibitor clade I, follistatin-like 1 precursor, complement factor H-related protein 1 precursor, Chain A Crystal Structure of Lipid-Free human Apolipoprotein A-1, phospholipase D3 isoform 2, Chain E Structure of human transferring receptor-transferrin complex, complement component C3, analogs and fragments thereof; and any combination thereof.
In other embodiments, the control protein expression profile is a late stage osteoarthritis expression profile, and the difference is indicative of early stage osteoarthritis. In such embodiments, the difference may be selected from the group consisting of an increase or decrease in the level of expression of one or more proteins selected from the group consisting of alpha-2-macroglobulin precursor, fibronectin precursor, Chain B structure of complement C3b, C9 complement protein, coagulation factor II precursor, alpha-1-antichymotrypsin, complement factor H, inter-alpha-trypsin heavy chain H1 precursor, complement factor H isoform a precursor, gelsolin isoform a precursor, inter-alpha-trypsin inhibitor heavy chain H4 precursor, phosphatidylinositol-glycan-specific phospholipase D1 precursor, inter-alpha-trypsin inhibitor family heavy chain-related protein, glycosylphosphatidylinositol specific phosphatase D1, complement component C6 precursor peptide, complement factor B, pre-pro-alpha(I) collagen, SERPIN2 protein, gp-180-carboxypeptidase D-like enzyme, Fibulin-1 isoform D precursor, plasminogen, HGF activator preproprotein, afamin precursor, Vitamin K-dependent protein, complement component 1 s subcomponent, inter-alpha-trypsin inhibitor, ASPIC, complement component 3 precursor, plasma kallikrein precursor, annexin A2 isoform 2, glucosamine(N-acetyl)-6-sulfatase precursor, (cystic fibrosis antigen), ezrin (p81) (cytovillin) (villin-2), S100 Calcium binding protein A9, coagulation factor XIII A chain precursor, peptidoglycan recognition protein L precursor, complement component 4 binding protein, inter-alpha-trypsin inhibitor heavy chain H1 precursor, fibrinogen gamma chain, Ig mu chain precursor, phospholipase D3 isoform, moesin, alpha-2-antiplasmin precursor, kininogen, thrombin inhibitor, Chain A antithrombin III, L-plastin, complement component 1, alpha-1-B-glycoprotein, hemopexin precursor, complement component C4A, apolipoprotein A-IV precursor, serum paraoxonase/arylesterase, preprohaptoglobulin, COMP, serpin peptidase inhibitor clade I, follistatin-like 1 precursor, complement factor H-related protein 1 precursor, Chain A Crystal Structure of Lipid-Free human Apolipoprotein A-1, phospholipase D3 isoform 2, Chain E Structure of human transferring receptor-transferrin complex, complement component C3, analogs and fragments thereof; and any combination thereof.
In other embodiments, the control protein expression profile is a healthy or normal expression profile, and the difference is indicative of early or late stage osteoarthritis. In such embodiments, the difference may be selected from the group consisting of an increase or decrease in the level of expression of one or more proteins selected from the group consisting of fibronectin precursor, alpha-2-macroglobulin precursor, Chain B Structure of Complement C3b, complement factor H, fibronectin 1 isoform 3 preproprotein, collagen type IV alpha 1, alph 2 type IV collagen preprotein, inter-alpha-trypsin inhibitor, C-terminal inter-alpha trypsin inhibitor, phosphatidylinositol-glycan-specific phospholipase D1, afamin precursor, complement component 6 isoform CRA_b, inter-alpha-trypsin inhibitor heavy chain-related protein, Chain A Crystal Structure of human Galectin-7, COMP, ALB protein, gelsolin isoform a precursor, complement factor B, fibulin-1 isoform D precursor, valosin-containing protein, Vitamin D-binding protein precursor, complement component 2 precursor, annexin A2, Annexin A2 isoform 2, homerin precursor, complement component 1 s subcomponent, ASPIC, Vitamin K-dependent protein, plasma kallikrein precursor, S100 calcium-binding protein A9, Protein S100-A7 (psoriasin), coagulation factor XIII, B Chain Alpha-Ferrous-Carbonmonoxy, coagulation factor II precursor, insulin-like growth factor binding protein acid labile subunit, histidine-rich glycoprotein precursor, phospholipid transfer protein isoform a precursor, antithrombin III, glucosamine(N-acetyl)-6-sulfatase precursor, coagulation factor XIII B chain, vitronectin, biotinidase precursor, acid labile subunit, alpha-1-B-glycoprotein, thrombin inhibitor, C9 complement protein, Coagulation factor XIII B chain precursor, hemopexin precursor, vanin 1 precursor, extracellular matrix protein 1 isoform precursor, histidine-rich glycoprotein, dopamine beta-hydroxylase precursor, peptidoglycan recognition protein L precursor, Chain A Crystal Structure of Native Heparin Cofactor Ii, fibrinogen gamma chain, inter-alpha (globulin) inhibitor H1, alpha-2-antiplasmin precursor, vitronectin precursor, Vitamin K-dependent protein S precursor, complement component 9, GRP78, analogs and fragments thereof; and any combination thereof.
In still other embodiments, the control protein expression profile is a late or early stage osteoarthritis expression profile, and the difference is indicative of normal or healthy subject. In such embodiments, the difference may be selected from the group consisting of an increase or decrease in the level of expression of one or more proteins selected from the group consisting of fibronectin precursor, alpha-2-macroglobulin precursor, Chain B Structure of Complement C3b, complement factor H, fibronectin 1 isoform 3 preproprotein, collagen type IV alpha 1, alph 2 type IV collagen preprotein, inter-alpha-trypsin inhibitor, C-terminal inter-alpha trypsin inhibitor, phosphatidylinositol-glycan-specific phospholipase D1, afamin precursor, complement component 6 isoform CRA_b, inter-alpha-trypsin inhibitor heavy chain-related protein, Chain A Crystal Structure of human Galectin-7, COMP, ALB protein, gelsolin isoform a precursor, complement factor B, fibulin-1 isoform D precursor, valosin-containing protein, Vitamin D-binding protein precursor, complement component 2 precursor, annexin A2, Annexin A2 isoform 2, hornerin precursor, complement component 1 subcomponent, ASPIC, Vitamin K-dependent protein, plasma kallikrein precursor, S100 calcium-binding protein A9, Protein S100-A7 (psoriasin), coagulation factor XIII, B Chain Alpha-Ferrous-Carbonmonoxy, coagulation factor II precursor, insulin-like growth factor binding protein acid labile subunit, histidine-rich glycoprotein precursor, phospholipid transfer protein isoform a precursor, antithrombin III, glucosamine(N-acetyl)-6-sulfatase precursor, coagulation factor XIII B chain, vitronectin, biotinidase precursor, acid labile subunit, alpha-1-B-glycoprotein, thrombin inhibitor, C9 complement protein, Coagulation factor XIII B chain precursor, hemopexin precursor, vanin 1 precursor, extracellular matrix protein 1 isoform precursor, histidine-rich glycoprotein, dopamine beta-hydroxylase precursor, peptidoglycan recognition protein L precursor, Chain A Crystal Structure of Native Heparin Cofactor Ii, fibrinogen gamma chain, inter-alpha (globulin) inhibitor H1, alpha-2-antiplasmin precursor, vitronectin precursor, Vitamin K-dependent protein S precursor, complement component 9, GRP78, analogs and fragments thereof; and any combination thereof.
In these methods, the biological sample can comprise a sample of blood or blood product, a sample of urine, a sample of joint fluid, a sample of saliva, or a sample of synovial fluid. In certain preferred embodiments, the biological sample comprises a sample of synovial fluid. Determination of the level of expression of one or more of polypeptides according to the present invention may comprise exposing the biological sample to at least one antibody specific for at least one of said polypeptides.
In certain embodiments, the subject is a human being, for example, a patient suspected of having osteoarthritis or a patient diagnosed with osteoarthritis but whose stage of osteoarthritis is unknown.
The inventive methods may further comprise a step of selecting a therapy for the subject based on the determination of the stage of osteoarthritis for the subject.
In yet another aspect, the present invention provides OA expression profile maps comprising expression level information for one or more of polypeptides selected from the group consisting of the proteins presented in Tables 1-6, analogs and fragments thereof. The OA expression profile may comprise expression level information for at least one biological sample obtained from a healthy individual, an individual with early stage osteoarthritis or an individual with late osteopathic osteoarthritis.
In still another aspect, the present invention provides kits for identifying the stage of osteoarthritis in a subject. Inventive kits comprise at least one reagent that specifically detects expression levels of at least one biomarker selected from the group consisting of: polypeptides selected from the group consisting of the proteins presented in Tables 1 and 3, analogs and fragments thereof, and nucleic acid molecules comprising polynucleotide sequences coding for polypeptides selected from the group consisting of the proteins presented in Tables 1 and 3, analogs and fragments thereof, and instructions for using said kits for identifying osteoarthritis in a subject as early Osteopathic or late osteoarthritic osteoarthritis.
In certain embodiments, the reagent that specifically detects expression levels of at least one biomarker comprises an antibody that specifically binds to at least one the polypeptides. In other embodiments, the reagent comprises a nucleic acid probe complementary to a polynucleotide sequence coding for at least one of the polypeptides. For example, the nucleic acid probe may be a cDNA or an oligonucleotide, and, in certain embodiments, is immobilized on a substrate surface.
Kits of the present invention may further comprise instructions required by a regulatory agency (e.g., the United States Food and Drug Administration) for use in in vitro diagnostic products; one or more of: extraction buffer/reagents and protocol, amplification buffer/reagents and protocol, hybridization buffer/reagents and protocol, immunodetection buffer/reagents and protocol, and labeling buffer/reagents and protocol, and/or at least one OA expression profile map as described above.
These and other objects, advantages and features of the present invention will become apparent to those of ordinary skill in the art having read the following detailed description of the preferred embodiments.
Throughout the specification, several terms are employed that are defined in the following paragraphs.
The term “subject” and “individual” are used herein interchangeably. They refer to a human or another mammal (e.g., primate, dog, cat, goat, horse, pig, mouse, rat, rabbit, and the like), that can be afflicted with osteoarthritis, but may or may not have the disease. In many embodiments, the subject is a human being.
The term “subject suspected of having osteoarthritis (OA)” refers to a subject that presents one or more symptoms indicative of OA (e.g., joint pain, localized tenderness, bony or soft tissue swelling, joint instability, crepitus) or that is being screened for OA (e.g., during a routine physical examination). A subject suspected of having OA may also have one or more risk factors (e.g., age, obesity, traumatic injury, overuse due to sports or occupational stresses, or family history). The term encompasses individuals who have not been tested for OA as well as individuals who have received an initial diagnosis (e.g., based on radiological examination) but for whom the stage of OA is not known.
The terms “osteoarthritis stage”, “osteoarthritis phase”, and “stage osteoarthritis” are used herein interchangeably and refer to the degree of advancement or progression of the disease. The present invention provides a means for determining the stage of the disease. In particular, the methods provided herein allows detection of “mild” or “early” stage OA, and of “severe” or “late” stage OA. Other staging systems known in the art include, for example, that developed by Marshall (W. Marshall, J. Rheumatol., 1996, 23: 582-584).
As used herein, the term “diagnosis” refers to a process aimed at determining if an individual is afflicted with a disease or ailment. In the context of the present invention, “diagnosis of OA” refers to a process aimed at one or more of: determining if an individual is afflicted with OA, and determining the stage of the disease (e.g., early OA or late OA).
The term “biological sample” is used herein in its broadest sense. A biological sample may be obtained from a subject (e.g., a human) or from components (e.g., tissues) of a subject. The sample may be of any biological tissue or fluid with which biomarkers of the present invention may be assayed. Frequently, the sample will be a “clinical sample”, i.e., a sample derived from a patient. Such samples include, but are not limited to, bodily fluids which may or may not contain cells, e.g., blood, urine, synovial fluid, saliva, and joint fluid; tissue or fine needle biopsy samples, such as from bone or cartilage; and archival samples with known diagnosis, treatment and/or outcome history. Biological samples may also include sections of tissues such as frozen sections taken from histological purposes. The term biological sample also encompasses any material derived by processing the biological sample. Derived materials include, but are not limited to, cells (or their progeny) isolated from the sample, proteins or nucleic acid molecules extracted from the sample. Processing of the biological sample may involve one or more of, filtration, distillation, extraction, concentration, inactivation of interfering components, addition of reagents, and the like.
The terms “normal” and “healthy” are used herein interchangeably. They refer to an individual or group of individuals who have not shown any OA symptoms, including joint pain, and have not been diagnosed with cartilage injury or OA. Preferably, said normal individual (or group of individuals) is not on medication affecting OA and has not been diagnosed with any other disease. In certain embodiments, normal individuals have similar sex, age, body mass index as compared with the individual from which the sample to be tested was obtained. The term “normal” is also used herein to qualify a sample isolated from a healthy individual.
In the context of the present invention, the term “control sample” refers to one or more biological samples isolated from an individual or group of individuals that are normal (i.e., healthy). A control sample can also refer to a biological sample isolated from a patient or group of patients diagnosed with a specific stage of OA (e.g., early OA or late OA). The term “control sample” (or “control”) can also refer to the compilation of data derived from samples of one or more individuals classified as normal, or one or more individuals diagnosed with OA, a specific stage of OA, or one or more individuals having undergone treatment of OA.
The terms “OA biomarker” and “biomarker” are used herein interchangeably. They refer to a protein selected from the set of proteins provided by the present invention and whose expression profile was found to be indicative of OA and/or a particular stage of OA. The term “biomarker” also encompasses nucleic acid molecules comprising a nucleotide sequence, which codes for a marker protein of the present invention as well as polynucleotides that hybridize with portions of these nucleic acid molecules.
As used herein, the term “indicative of OA”, when applied to a biomarker, refers to an expression pattern or profile which is diagnostic of OA or a stage of OA such that the expression pattern is found significantly more often in patients with the disease or a stage of the disease than in patients without the disease or another stage of the disease (as determined using routine statistical methods setting confidence levels at a minimum of 95%). Preferably, an expression pattern which is indicative of OA is found in at least 60% of patients who have the disease and is found in less than 10% of subjects who do not have the disease. More preferably, an expression pattern which is indicative of OA is found in at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95% or more in patients who have the disease and is found in less than 10%, less than 8%, less than 5%, less than 2.5%, or less than 1% of subjects who do not have the disease.
As used herein, the term “differentially expressed biomarker” refers to a biomarker whose level of expression is different in a subject (or a population of subjects) afflicted with OA relative to its level of expression in a healthy or normal subject (or a population of healthy or normal subjects). The term also encompasses a biomarker whose level of expression is different at different stages of the disease (e.g., mild or early OA, severe or late OA). Differential expression includes quantitative, as well as qualitative, differences in the temporal or cellular expression pattern of the biomarker. As described in greater details below, a differentially expressed biomarker, alone or in combination with other differentially expressed biomarkers, is useful in a variety of different applications in diagnostic, staging, therapeutic, drug development and related areas. The expression patterns of the differentially expressed biomarkers disclosed herein can be described as a fingerprint or a signature of OA, OA stage and OA progression. They can be used as a point of reference to compare and characterize unknown samples and samples for which further information is sought. The term “decreased level of expression” as used herein, refers to a decrease in expression of at least 10% or more. For example, 20%, 30%, 40%, or 50%, 60%, 70%, 80%, 90% or more, or a decrease in expression of greater than 1-fold, 2-fold, 3-fold, 4-fold, 5-fold, 10-fold, 50-fold, 100-fold or more as measured by one or more methods described herein. The term “increased level of expression” as used herein, refers to an increase in expression of at least 10% or more. For example, 20%, 30%, 40%, or 50%, 60%, 70%, 80%, 90% or more or an increase in expression of greater than I-fold, 2-fold, 3-fold, 4-fold, 5-fold, 10-fold, 50-fold, 100-fold or more as measured by one or more methods, such as method described herein.
The terms “protein”, “polypeptide”, and “peptide” are used herein interchangeably, and refer to amino acid sequences of a variety of lengths, either in their neutral (uncharged) forms or as salts, and either unmodified or modified by glycosylation, side chain oxidation, or phosphorylation. In certain embodiments, the amino acid sequence is the full-length native protein. In other embodiments, the amino acid sequence is a smaller fragment of the full-length protein. In still other embodiments, the amino acid sequence is modified by additional substituents attached to the amino acid side chains, such as glycosyl units, lipids, or inorganic ions such as phosphates, as well as modifications relating to chemical conversion of the chains, such as oxidation of sulfhydryl groups. Thus, the term “protein” (or its equivalent terms) is intended to include the amino acid sequence of the full-length native protein, subject to those modifications that do not change its specific properties. In particular, the term “protein” encompasses protein isoforms, i.e., variants that are encoded by the same gene, but that differ in their pI or MW, or both. Such isoforms can differ in their amino acid sequence (e.g., as a result of alternative splicing or limited proteolysis), or in the alternative, may arise from differential post-translational modification (e.g., glycosylation, acylation, phosphorylation).
The term “protein analog”, as used herein, refers to a polypeptide that possesses a similar or identical function as the full-length native protein but need not necessarily comprise an amino acid sequence that is similar or identical to the amino acid sequence of the protein, or possesses a structure that is similar or identical to that of the protein. Preferably, in the context of the present invention, a protein analog has an amino acid sequence that is at least 30% (more preferably, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95% or at least 99%) identical to the amino acid sequence of the full-length native protein.
The term “protein fragment”, as used herein, refers to a polypeptide comprising an amino acid sequence of at least 4 amino acid residues (preferably, at least 10 amino acid residues, at least 15 amino acid residues, at least 20 amino acid residues, at least 25 amino acid residues, at least 40 amino acid residues, at least 50 amino acid residues, at least 60 amino acid residues, at least 70 amino acid residues, at least 80 amino acid residues, at least 90 amino acid residues, at least 100 amino acid residues, at least 125 amino acid residues, at least 150 amino acid residues, at least 175 amino acid residues, at least 200 amino acid residues, or at least 250 amino acid residues) of the amino acid sequence of a second polypeptide. The fragment of a marker protein may or may not possess a functional activity of the full-length native protein.
The terms “nucleic acid molecule” and “polynucleotide” are used herein interchangeably. They refer to a deoxyribonucleotide or ribonucleotide polymer in either single- or double-stranded form, and unless otherwise stated, encompass known analogs of natural nucleotides that can function in a similar manner as naturally occurring nucleotides. The terms encompass nucleic acid-like structures with synthetic backbones, as well as amplification products.
As used herein, the term “a reagent that specifically detects expression levels” refers to one or more reagents used to detect the expression level of one or more biomarkers (e.g., a polypeptide selected from the marker proteins provided herein, a nucleic acid molecule comprising a polynucleotide sequence coding for a marker protein, or a polynucleotide that hybridizes with at least a portion of the nucleic acid molecule). Examples of suitable reagents include, but are not limited to, antibodies capable of specifically binding to a marker protein of interest, nucleic acid probes capable of specifically hybridizing to a polynucleotide sequence of interest, or PCR primers capable of specifically amplifying a polynucleotide sequence of interest. The term “amplify” is used herein in the broad sense to mean creating/generating an amplification product. “Amplification”, as used herein, generally refers to the process of producing multiple copies of a desired sequence, particularly those of a sample. A “copy” does not necessarily mean perfect sequence complementarity or identity to the template sequence.
The term “hybridizing” refers to the binding of two single stranded nucleic acids via complementary base pairing. The term “specific hybridization” refers to a process in which a nucleic acid molecule preferentially binds, duplexes, or hybridizes to a particular nucleic acid sequence under stringent conditions (e.g., in the presence of competitor nucleic acids with a lower degree of complementarity to the hybridizing strand). In certain embodiments of the present invention, these terms more specifically refer to a process in which a nucleic acid fragment (or segment) from a test sample preferentially binds to a particular probe and to a lesser extent or not at all, to other probes, for example, when these probes are immobilized on an array.
The terms “array”, “micro-array”, and “biochip” are used herein interchangeably. They refer to an arrangement, on a substrate surface, of hybridizable array elements, preferably, multiple nucleic acid molecules of known sequences. Each nucleic acid molecule is immobilized to a discrete spot (i.e., a defined location or assigned position) on the substrate surface. The term “micro-array” more specifically refers to an array that is miniaturized so as to require microscopic examination for visual evaluation.
The term “probe”, as used herein, refers to a nucleic acid molecule of known sequence, which can be a short DNA sequence (i.e., an oligonucleotide), a PCR product, or mRNA isolate. Probes are specific DNA sequences to which nucleic acid fragments from a test sample are hybridized. Probes specifically bind to nucleic acids of complementary or substantially complementary sequence through one or more types of chemical bonds, usually through hydrogen bond formation.
The terms “labeled”, “labeled with a detectable agent” and “labeled with a detectable moiety” are used herein interchangeably. These terms are used to specify that an entity (e.g., a probe) can be visualized, for example, following binding to another entity (e.g., a polynucleotide or polypeptide). Preferably, the detectable agent or moiety is selected such that it generates a signal which can be measured and whose intensity is related to the amount of bound entity. In array-based methods, the detectable agent or moiety is also preferably selected such that it generates a localized signal, thereby allowing spatial resolution of the signal from each spot on the array. Methods for labeling polypeptides or polynucleotides are well-known in the art. Labeled polypeptides or polynucleotides can be prepared by incorporation of or conjugation to a label, that is directly or indirectly detectable by spectroscopic, photochemical, biochemical, immunochemical, electrical, optical, or chemical means. Suitable detectable agents include, but are not limited to, various ligands, radionuclides, fluorescent dyes, chemiluminescent agents, microparticles, enzymes, calorimetric labels, magnetic labels, and haptens. Detectable moieties can also be biological molecules such as molecular beacons and aptamer beacons.
The term “OA expression profile map” refers to a presentation of expression levels of a set of biomarkers in a particular status of OA (e.g., absence of disease, OA, early OA and late OA). The map may be presented as a graphical representation (e.g., on paper or a computer screen), a physical representation (e.g., a gel or array) or a digital representation stored in a computer-readable medium. Each map corresponds to a particular status of the disease (e.g., absence of disease, OA, early OA and late OA), and thus provides a template for comparison to a patient sample. In certain preferred embodiments, maps are generated from a plurality of samples obtained from a significant number of normal individuals or individuals with the same stage/status of OA. Maps may be established for individuals with matched age, sex and body mass index.
The term “computer readable medium” refers to any device or system for storing or providing information (e.g., data and instructions) to a computer processor. Examples of computer readable media include, but are not limited to, DVDs, CDs, hard disk drives, magnetic tape and servers for streaming media over networks.
The terms “compound” and “agent” are used herein interchangeably. They refer to any naturally occurring or non-naturally occurring (i.e., synthetic or recombinant) molecule, such as a biological macromolecule (e.g., nucleic acid, polypeptide or protein), organic or inorganic molecule, or an extract made from biological materials such as bacteria, plants, fungi, or animal (particularly mammalian, including human) cells or tissues. The compound may be a single molecule or a mixture or complex of at least two molecules.
The term “candidate compound” refers to a compound or agent (as defined above) that is to be tested for an activity of interest. In the screening methods of the present invention, candidate compounds are evaluated for their ability to modulate (e.g., increase or decrease) the expression level of one or more of the biomarkers provided herein. Particularly interesting are candidate compounds that can restore the expression profile of one or more disease indicative biomarkers of a patient with OA to an expression profile more similar to that of an individual afflicted with an earlier stage of the disease or to that of a normal individual. Such compounds are potential “OA therapeutic agents”.
As used herein, the term “effective amount” refers to an amount of a compound or agent that is sufficient to fulfill its intended purpose(s). In the context of the present invention, the purpose(s) may be, for example: to modulate the expression of at least one inventive biomarker; and/or to delay or prevent the onset of OA; and/or to slow down or stop the progression, aggravation, or deterioration of the symptoms of OA; and/or to bring about amelioration of the symptoms of OA, and/or to cure OA.
The term “system” and “biological system” are used herein interchangeably. A system may be any biological entity that can express or comprise at least one inventive biomarker. In the context of the present invention, in vitro, in vivo, and ex vivo systems are considered; and the system may be a cell, a biological fluid, a biological tissue, or an animal. For example, a system may originate from a living subject (e.g., it may be obtained by drawing blood, or by performing needle biopsy), or from a deceased subject (e.g., it may be obtained at autopsy).
A “pharmaceutical composition” is defined herein as comprising at least one compound of the invention (i.e., a candidate compound identified by an inventive screening method as a modulator of the expression of at least one inventive biomarker), and at least one pharmaceutically acceptable carrier.
As used herein, the term “pharmaceutically acceptable carrier” refers to a carrier medium which does not interfere with the effectiveness of the biological activity of the active ingredients and which is not excessively toxic to the host at the concentrations at which it is administered. The term includes solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic agents, absorption delaying agents, and the like. The use of such media and agents for pharmaceutically active substances is well known in the art (see, for example, Remington's Pharmaceutical Sciences, E. W. Martin, 18th Ed., 1990, Mack Publishing Co., Easton, Pa.).
The term “treatment” is used herein to characterize a method that is aimed at (1) delaying or preventing the onset of OA; or (2) slowing down or stopping the progression, aggravation, or deterioration of the symptoms of the condition; or (3) bringing about ameliorations of the symptoms of the condition; or (4) curing the condition. A treatment may be administered prior to the onset of the disease, for a prophylactic or preventive action. It may also be administered after initiation of the disease, for a therapeutic action.
The present invention relates to improved systems and strategies for the diagnostic, characterization, and staging of OA. In particular, the present invention provides the identity of biomarkers whose expression has been found to correlate with OA and OA progression.
In one aspect, the present invention provides the identity of a set of proteins indicative of OA identified using high-throughput proteomics technology. The protein markers indicative of OA are listed in Tables 1, 2, 3, 4, 5, and 6. More specifically, by analyzing samples of serum protein depleted, age-matched synovial fluid obtained from healthy patients and from patients with early OA or late OA, it was found that the proteins listed in Tables 1, 2, 3, 4, 5 and 6 can be used to discriminate between normal/healthy and early OA and normal/healthy and late OA. It was also found that the proteins listed in Tables 1, 2, 3, 4, 5 and 6 can be used to discriminate between early OA, late OA, and healthy individuals.
The samples of synovial fluid obtained from patients with early and late OA compared to samples of synovial fluid obtained from normal individuals exhibit differing expression levels (i.e., increased expression levels and decreased levels of expression) of the proteins listed of the proteins listed in Tables 1, 2, 3, 4, 5, and 6. Therefore, the expression profiles of the proteins presented in Tables 1, 2, 3, 4, 5, and 6 can be used to diagnose OA as well as to determine the presence and/or degree of advancement of the disease (i.e., to determine the stage of the disease).
In one embodiment, the proteins can comprise at least one of alpha-2-macroglobulin precursor, fibronectin precursor, Chain B structure of complement C3b, C9 complement protein, coagulation factor II precursor, alpha-1-antichymotrypsin, complement component C3, complement factor H, inter-alpha-trypsin heavy chain H1 precursor, complement factor H isoform a precursor, gelsolin isoform a precursor, ceruloplasmin, inter-alpha-trypsin inhibitor heavy chain H4 precursor, phosphatidylinositol-glycan-specific phospholipase D1 precursor, inter-alpha-trypsin inhibitor family heavy chain-related protein, glycosylphosphatidylinositol specific phosphatase D1, complement component C6 precursor peptide, complement factor B, pre-pro-alpha(I) collagen, SERPIN2 protein, gp-180-carboxypeptidase D-like enzyme, Fibulin-1 isoform D precursor, plasminogen, HGF activator preproprotein, afamin precursor, Vitamin K-dependent protein, complement component 1 s subcomponent, inter-alpha-trypsin inhibitor, ASPIC, complement component 3 precursor, plasma kallikrein precursor, annexin A2 isoform 2, glucosamine(N-acetyl)-6-sulfatase precursor, (cystic fibrosis antigen), ezrin (p81) (cytovillin) (villin-2), S100 Calcium binding protein A9, coagulation factor XIII A chain precursor, peptidoglycan recognition protein L precursor, complement component 4 binding protein, inter-alpha-trypsin inhibitor heavy chain H1 precursor, fibrinogen gamma chain, Ig mu chain precursor, phospholipase D3 isoform, moesin, alpha-2-antiplasmin precursor, kininogen, thrombin inhibitor, Chain A antithrombin III, L-plastin, complement component 1, alpha-1-B-glycoprotein, hemopexin precursor, complement component C4A, apolipoprotein A-IV precursor, serum paraoxonase/arylesterase, preprohaptoglobulin, COMP, serpin peptidase inhibitor clade I, follistatin-like 1 precursor, complement factor H-related protein 1 precursor, Chain A Crystal Structure of Lipid-Free human Apolipoprotein A-1, phospholipase D3 isoform 2, Chain E Structure of human transferring receptor-transferrin complex, complement component C3, analogs and fragments thereof; and any combination thereof.
In other embodiments, the proteins can comprise at least one of alpha-2-macroglobulin precursor, fibronectin precursor, Chain B structure of complement C3b, C9 complement protein, coagulation factor II precursor, alpha-1-antichymotrypsin, complement factor H, inter-alpha-trypsin heavy chain H1 precursor, complement factor H isoform a precursor, gelsolin isoform a precursor, inter-alpha-trypsin inhibitor heavy chain H4 precursor, phosphatidylinositol-glycan-specific phospholipase D1 precursor, inter-alpha-trypsin inhibitor family heavy chain-related protein, glycosylphosphatidylinositol specific phosphatase D1, complement component C6 precursor peptide, complement factor B, pre-pro-alpha(I) collagen, SERPIN2 protein, gp-180-carboxypeptidase D-like enzyme, Fibulin-1 isoform D precursor, plasminogen, HGF activator preproprotein, afamin precursor, Vitamin K-dependent protein, complement component 1 s subcomponent, inter-alpha-trypsin inhibitor, ASPIC, complement component 3 precursor, plasma kallikrein precursor, annexin A2 isoform 2, glucosamine(N-acetyl)-6-sulfatase precursor, (cystic fibrosis antigen), ezrin (p81) (cytovillin) (villin-2), 5100 Calcium binding protein A9, coagulation factor XIII A chain precursor, peptidoglycan recognition protein L precursor, complement component 4 binding protein, inter-alpha-trypsin inhibitor heavy chain H1 precursor, fibrinogen gamma chain, Ig mu chain precursor, phospholipase D3 isoform, moesin, alpha-2-antiplasmin precursor, kininogen, thrombin inhibitor, Chain A antithrombin III, L-plastin, complement component 1, alpha-1-B-glycoprotein, hemopexin precursor, complement component C4A, apolipoprotein A-IV precursor, serum paraoxonase/arylesterase, preprohaptoglobulin, COMP, serpin peptidase inhibitor clade I, follistatin-like 1 precursor, complement factor H-related protein 1 precursor, Chain A Crystal Structure of Lipid-Free human Apolipoprotein A-1, phospholipase D3 isoform 2, Chain E Structure of human transferring receptor-transferrin complex, complement component C3, analogs and fragments thereof; and any combination thereof.
In still other embodiments, the proteins can comprise at least one of fibronectin precursor, complement component C3, alpha-2-macroglobulin precursor, Chain B Structure of Complement C3b, complement factor H, fibronectin 1 isoform 3 preproprotein, alpha-2-macroglobulin, collagen type IV alpha 1, alph 2 type IV collagen preprotein, inter-alpha-trypsin inhibitor, C-terminal inter-alpha trypsin inhibitor, ceruloplasmin, phosphatidylinositol-glycan-specific phospholipase D1, afamin precursor, complement component 6 isoform CRA_b, inter-alpha-trypsin inhibitor heavy chain-related protein, Chain A Crystal Structure of human Galectin-7, serum albumin, COMP, ALB protein, gelsolin isoform a precursor, complement factor B, fibulin-1 isoform D precursor, inter-alpha-globulin inhibitor H4, valosin-containing protein, Vitamin D-binding protein precursor, complement component 2 precursor, annexin A2, Annexin A2 isoform 2, homerin precursor, complement component 1 s subcomponent, ASPIC, Vitamin K-dependent protein, plasma kallikrein precursor, S100 calcium-binding protein A9, Protein S100-A7 (psoriasin), coagulation factor XIII, B Chain Alpha-Ferrous-Carbonmonoxy, coagulation factor II precursor, insulin-like growth factor binding protein acid labile subunit, histidine-rich glycoprotein precursor, phospholipid transfer protein isoform a precursor, antithrombin III, glucosamine(N-acetyl)-6-sulfatase precursor, coagulation factor XIII B chain, vitronectin, biotinidase precursor, acid labile subunit, alpha-1-B-glycoprotein, thrombin inhibitor, C9 complement protein, Coagulation factor XIII B chain precursor, hemopexin precursor, vanin 1 precursor, extracellular matrix protein 1 isoform precursor, histidine-rich glycoprotein, dopamine beta-hydroxylase precursor, peptidoglycan recognition protein L precursor, Chain A Crystal Structure of Native Heparin Cofactor Ii, fibrinogen gamma chain, inter-alpha (globulin) inhibitor H1, alpha-2-antiplasmin precursor, vitronectin precursor, Vitamin K-dependent protein S precursor, complement component 9, GRP78, analogs and fragments thereof; and any combination thereof.
In further embodiments, the proteins can comprise at least one of fibronectin precursor, alpha-2-macroglobulin precursor, Chain B Structure of Complement C3b, complement factor H, fibronectin 1 isoform 3 preproprotein, collagen type IV alpha 1, alph 2 type IV collagen preprotein, inter-alpha-trypsin inhibitor, C-terminal inter-alpha trypsin inhibitor, phosphatidylinositol-glycan-specific phospholipase D1, afamin precursor, complement component 6 isoform CRA_b, inter-alpha-trypsin inhibitor heavy chain-related protein, Chain A Crystal Structure of human Galectin-7, COMP, ALB protein, gelsolin isoform a precursor, complement factor B, fibulin-1 isoform D precursor, valosin-containing protein, Vitamin D-binding protein precursor, complement component 2 precursor, annexin A2, Annexin A2 isoform 2, homerin precursor, complement component 1 s subcomponent, ASPIC, Vitamin K-dependent protein, plasma kallikrein precursor, S100 calcium-binding protein A9, Protein S100-A7 (psoriasin), coagulation factor XIII, B Chain Alpha-Ferrous-Carbonmonoxy, coagulation factor II precursor, insulin-like growth factor binding protein acid labile subunit, histidine-rich glycoprotein precursor, phospholipid transfer protein isoform a precursor, antithrombin III, glucosamine(N-acetyl)-6-sulfatase precursor, coagulation factor XIII B chain, vitronectin, biotinidase precursor, acid labile subunit, alpha-1-B-glycoprotein, thrombin inhibitor, C9 complement protein, Coagulation factor XIII B chain precursor, hemopexin precursor, vanin 1 precursor, extracellular matrix protein 1 isoform precursor, histidine-rich glycoprotein, dopamine beta-hydroxylase precursor, peptidoglycan recognition protein L precursor, Chain A Crystal Structure of Native Heparin Cofactor Ii, fibrinogen gamma chain, inter-alpha (globulin) inhibitor H1, alpha-2-antiplasmin precursor, vitronectin precursor, Vitamin K-dependent protein S precursor, complement component 9, GRP78, analogs and fragments thereof; and any combination thereof.
In still other embodiments, the proteins can comprise at least one of alpha-2-macroglobulin precursor, fibronectin precursor, Chain B structure of complement C3b, C9 complement protein, coagulation factor II precursor, alpha-1-antichymotrypsin, complement component C3, complement factor H, inter-alpha-trypsin heavy chain H1 precursor, complement factor H isoform a precursor, gelsolin isoform a precursor, ceruloplasmin, inter-alpha-trypsin inhibitor heavy chain H4 precursor, phosphatidylinositol-glycan-specific phospholipase D1 precursor, inter-alpha-trypsin inhibitor family heavy chain-related protein, glycosylphosphatidylinositol specific phosphatase D1, complement component C6 precursor peptide, complement factor B, pre-pro-alpha(I) collagen, SERPIN2 protein, gp-180-carboxypeptidase D-like enzyme, Fibulin-1 isoform D precursor, plasminogen, HGF activator preproprotein, afamin precursor, Vitamin K-dependent protein, complement component 1 s subcomponent, inter-alpha-trypsin inhibitor, ASPIC, complement component 3 precursor, plasma kallikrein precursor, annexin A2 isoform 2, glucosamine(N-acetyl)-6-sulfatase precursor, (cystic fibrosis antigen), ezrin (p81) (cytovillin) (villin-2), S100 Calcium binding protein A9, coagulation factor XIII A chain precursor, peptidoglycan recognition protein L precursor, complement component 4 binding protein, inter-alpha-trypsin inhibitor heavy chain H1 precursor, fibrinogen gamma chain, Ig mu chain precursor, phospholipase D3 isoform, moesin, alpha-2-antiplasmin precursor, kininogen, thrombin inhibitor, Chain A antithrombin III, L-plastin, complement component 1, alpha-1-B-glycoprotein, hemopexin precursor, complement component C4A, apolipoprotein A-IV precursor, serum paraoxonase/arylesterase, preprohaptoglobulin, COMP, serpin peptidase inhibitor clade I, follistatin-like 1 precursor, complement factor H-related protein 1 precursor, Chain A Crystal Structure of Lipid-Free human Apolipoprotein A-1, phospholipase D3 isoform 2, Chain E Structure of human transferring receptor-transferrin complex, complement component C3, fibronectin 1 isoform 3 preproprotein, alpha-2-macroglobulin, collagen type IV alpha 1, C-terminal inter-alpha trypsin inhibitor, phosphatidylinositol-glycan-specific phospholipase D1, complement component 6 isoform CRA_b, Chain A Crystal Structure of human Galectin-7, serum albumin, ALB protein, inter-alpha-globulin inhibitor H4, valosin-containing protein, Vitamin D-binding protein precursor, complement component 2 precursor, annexin A2, homerin precursor, Protein S100-A7 (psoriasin), coagulation factor XIII, B Chain Alpha-Ferrous-Carbonmonoxy, insulin-like growth factor binding protein acid labile, histidine-rich glycoprotein precursor, phospholipid transfer protein isoform a precursor, coagulation factor XIII B chain, vitronectin, biotinidase precursor, alpha-1-B-glycoprotein, Coagulation factor XIII B chain precursor, vanin 1 precursor, extracellular matrix protein 1 isoform precursor, histidine-rich glycoprotein, dopamine beta-hydroxylase precursor, Chain A Crystal Structure of Native Heparin Cofactor Ii, inter-alpha (globulin) inhibitor H1, vitronectin precursor, Vitamin K-dependent protein S precursor, GRP78, analogs and fragments thereof; and any combination thereof.
In other embodiments, the proteins can comprise at least one of alpha-2-macroglobulin precursor, fibronectin precursor, Chain B structure of complement C3b, C9 complement protein, coagulation factor II precursor, alpha-1-antichymotrypsin, complement factor H, inter-alpha-trypsin heavy chain H1 precursor, complement factor H isoform a precursor, gelsolin isoform a precursor, inter-alpha-trypsin inhibitor heavy chain H4 precursor, phosphatidylinositol-glycan-specific phospholipase D1 precursor, inter-alpha-trypsin inhibitor family heavy chain-related protein, glycosylphosphatidylinositol specific phosphatase D1, complement component C6 precursor peptide, complement factor B, pre-pro-alpha(I) collagen, SERPIN2 protein, gp-180-carboxypeptidase D-like enzyme, Fibulin-1 isoform D precursor, plasminogen, HGF activator preproprotein, afamin precursor, Vitamin K-dependent protein, complement component 1 s subcomponent, inter-alpha-trypsin inhibitor, ASPIC, complement component 3 precursor, plasma kallikrein precursor, annexin A2 isoform 2, glucosamine(N-acetyl)-6-sulfatase precursor, (cystic fibrosis antigen), ezrin (p81) (cytovillin) (villin-2), 5100 Calcium binding protein A9, coagulation factor XIII A chain precursor, peptidoglycan recognition protein L precursor, complement component 4 binding protein, inter-alpha-trypsin inhibitor heavy chain H1 precursor, fibrinogen gamma chain, Ig mu chain precursor, phospholipase D3 isoform, moesin, alpha-2-antiplasmin precursor, kininogen, thrombin inhibitor, Chain A antithrombin III, L-plastin, complement component 1, alpha-1-B-glycoprotein, hemopexin precursor, complement component C4A, apolipoprotein A-IV precursor, serum paraoxonase/arylesterase, preprohaptoglobulin, COMP, serpin peptidase inhibitor clade I, follistatin-like 1 precursor, complement factor H-related protein 1 precursor, Chain A Crystal Structure of Lipid-Free human Apolipoprotein A-1, phospholipase D3 isoform 2, Chain E Structure of human transferring receptor-transferrin complex, complement component C3, fibronectin 1 isoform 3 preproprotein, collagen type IV alpha 1, C-terminal inter-alpha trypsin inhibitor, phosphatidylinositol-glycan-specific phospholipase D1, complement component 6 isoform CRA_b, Chain A Crystal Structure of human Galectin-7, ALB protein, valosin-containing protein, Vitamin D-binding protein precursor, complement component 2 precursor, annexin A2, homerin precursor, Protein S100-A7 (psoriasin), coagulation factor XIII, B Chain Alpha-Ferrous-Carbonmonoxy, insulin-like growth factor binding protein acid labile, histidine-rich glycoprotein precursor, phospholipid transfer protein isoform a precursor, coagulation factor XIII B chain, vitronectin, biotinidase precursor, alpha-1-B-glycoprotein, Coagulation factor XIII B chain precursor, vanin 1 precursor, extracellular matrix protein 1 isoform precursor, histidine-rich glycoprotein, dopamine beta-hydroxylase precursor, Chain A Crystal Structure of Native Heparin Cofactor Ii, inter-alpha (globulin) inhibitor H1, vitronectin precursor, Vitamin K-dependent protein S precursor, GRP78, analogs and fragments thereof; and any combination thereof.
Other OA biomarkers provided by the present invention include nucleic acid molecules comprising polynucleotide sequences coding for the inventive protein markers described above (or analogs and fragments thereof) and polynucleotides that hybridize with portions of these nucleic acid molecules.
Information on expression levels of a given set of biomarkers obtained using biological samples from individuals afflicted with a particular stage of the disease (e.g., healthy subjects, patients with OA, with early OA, or with late OA) may be grouped to form an OA expression profile map. Preferably, an OA expression profile map results from the study of a large number of individuals with the same disease stage/status. In certain embodiments, an OA expression profile map is established using samples from individuals with matched age, sex, and body index. Each expression profile map provides a template for comparison to biomarker expression patterns generated from unknown biological samples. OA expression profile maps may be presented as a graphical representation (e.g., on paper or a computer screen), a physical representation (e.g., a gel or array) or a digital representation stored in a computer-readable medium.
As will be appreciated by those of ordinary skill in the art, sets of biomarkers whose expression profiles correlate with OA, can discriminate between different stages of the disease may be used to identify, study or characterize unknown biological samples. Accordingly, the present invention provides methods for characterizing biological samples obtained from a subject suspected of having OA, for diagnosing OA in a subject, and for assessing the advancement of OA in a subject. In such methods, the biomarkers' expression levels determined for a biological sample obtained from the subject are compared to the levels in one or more control samples. The control samples may be obtained from a healthy individual (or a group of healthy individuals), from an individual (or group of individuals) afflicted with OA, and/or from an individual (or group of individuals) afflicted with a specific stage of the disease (e.g., early OA or late OA). As mentioned above, the control expression levels of the biomarkers of interest are preferably determined from a significant number of individuals, and an average or mean is obtained. In certain preferred embodiments, the expression levels determined for the biological sample under investigation are compared to at least one expression profile map for OA, as described above.
In certain embodiments, the control protein expression profile is an early stage osteoarthritis expression profile, and the difference is indicative of late stage osteoarthritis. In such embodiments, the difference may be selected from the group consisting of an increase or decrease in the level of expression of one or more proteins selected from the group consisting of alpha-2-macroglobulin precursor, fibronectin precursor, Chain B structure of complement C3b, C9 complement protein, coagulation factor II precursor, alpha-1-antichymotrypsin, complement factor H, inter-alpha-trypsin heavy chain H1 precursor, complement factor H isoform a precursor, gelsolin isoform a precursor, inter-alpha-trypsin inhibitor heavy chain H4 precursor, phosphatidylinositol-glycan-specific phospholipase D1 precursor, inter-alpha-trypsin inhibitor family heavy chain-related protein, glycosylphosphatidylinositol specific phosphatase D1, complement component C6 precursor peptide, complement factor B, pre-pro-alpha(I) collagen, SERPIN2 protein, gp-180-carboxypeptidase D-like enzyme, Fibulin-1 isoform D precursor, plasminogen, HGF activator preproprotein, afamin precursor, Vitamin K-dependent protein, complement component 1 s subcomponent, inter-alpha-trypsin inhibitor, ASPIC, complement component 3 precursor, plasma kallikrein precursor, annexin A2 isoform 2, glucosamine(N-acetyl)-6-sulfatase precursor, (cystic fibrosis antigen), ezrin (p81) (cytovillin) (villin-2), S100 Calcium binding protein A9, coagulation factor XIII A chain precursor, peptidoglycan recognition protein L precursor, complement component 4 binding protein, inter-alpha-trypsin inhibitor heavy chain H1 precursor, fibrinogen gamma chain, Ig mu chain precursor, phospholipase D3 isoform, moesin, alpha-2-antiplasmin precursor, kininogen, thrombin inhibitor, Chain A antithrombin III, L-plastin, complement component 1, alpha-1-B-glycoprotein, hemopexin precursor, complement component C4A, apolipoprotein A-IV precursor, serum paraoxonase/arylesterase, preprohaptoglobulin, COMP, serpin peptidase inhibitor clade I, follistatin-like 1 precursor, complement factor H-related protein 1 precursor, Chain A Crystal Structure of Lipid-Free human Apolipoprotein A-1, phospholipase D3 isoform 2, Chain E Structure of human transferring receptor-transferrin complex, complement component C3, analogs and fragments thereof; and any combination thereof.
In other embodiments, the control protein expression profile is a late stage osteoarthritis expression profile, and the difference is indicative of early stage osteoarthritis. In such embodiments, the difference may be selected from the group consisting of an increase or decrease in the level of expression of one or more proteins selected from the group consisting of alpha-2-macroglobulin precursor, fibronectin precursor, Chain B structure of complement C3b, C9 complement protein, coagulation factor II precursor, alpha-1-antichymotrypsin, complement factor H, inter-alpha-trypsin heavy chain H1 precursor, complement factor H isoform a precursor, gelsolin isoform a precursor, inter-alpha-trypsin inhibitor heavy chain H4 precursor, phosphatidylinositol-glycan-specific phospholipase D1 precursor, inter-alpha-trypsin inhibitor family heavy chain-related protein, glycosylphosphatidylinositol specific phosphatase D1, complement component C6 precursor peptide, complement factor B, pre-pro-alpha(I) collagen, SERPIN2 protein, gp-180-carboxypeptidase D-like enzyme, Fibulin-1 isoform D precursor, plasminogen, HGF activator preproprotein, afamin precursor, Vitamin K-dependent protein, complement component 1 s subcomponent, inter-alpha-trypsin inhibitor, ASPIC, complement component 3 precursor, plasma kallikrein precursor, annexin A2 isoform 2, glucosamine(N-acetyl)-6-sulfatase precursor, (cystic fibrosis antigen), ezrin (p81) (cytovillin) (villin-2), S100 Calcium binding protein A9, coagulation factor XIII A chain precursor, peptidoglycan recognition protein L precursor, complement component 4 binding protein, inter-alpha-trypsin inhibitor heavy chain H1 precursor, fibrinogen gamma chain, Ig mu chain precursor, phospholipase D3 isoform, moesin, alpha-2-antiplasmin precursor, kininogen, thrombin inhibitor, Chain A antithrombin III, L-plastin, complement component 1, alpha-1-B-glycoprotein, hemopexin precursor, complement component C4A, apolipoprotein A-IV precursor, serum paraoxonase/arylesterase, preprohaptoglobulin, COMP, serpin peptidase inhibitor clade I, follistatin-like 1 precursor, complement factor H-related protein 1 precursor, Chain A Crystal Structure of Lipid-Free human Apolipoprotein A-1, phospholipase D3 isoform 2, Chain E Structure of human transferring receptor-transferrin complex, complement component C3, analogs and fragments thereof; and any combination thereof.
In other embodiments, the control protein expression profile is a healthy or normal expression profile, and the difference is indicative of early or late stage osteoarthritis. In such embodiments, the difference may be selected from the group consisting of an increase or decrease in the level of expression of one or more proteins selected from the group consisting of fibronectin precursor, alpha-2-macroglobulin precursor, Chain B Structure of Complement C3b, complement factor H, fibronectin 1 isoform 3 preproprotein, collagen type IV alpha 1, alph 2 type IV collagen preprotein, inter-alpha-trypsin inhibitor, C-terminal inter-alpha trypsin inhibitor, phosphatidylinositol-glycan-specific phospholipase D1, afamin precursor, complement component 6 isoform CRA_b, inter-alpha-trypsin inhibitor heavy chain-related protein, Chain A Crystal Structure of human Galectin-7, COMP, ALB protein, gelsolin isoform a precursor, complement factor B, fibulin-1 isoform D precursor, valosin-containing protein, Vitamin D-binding protein precursor, complement component 2 precursor, annexin A2, Annexin A2 isoform 2, hornerin precursor, complement component 1 s subcomponent, ASPIC, Vitamin K-dependent protein, plasma kallikrein precursor, S100 calcium-binding protein A9, Protein S100-A7 (psoriasin), coagulation factor XIII, B Chain Alpha-Ferrous-Carbonmonoxy, coagulation factor II precursor, insulin-like growth factor binding protein acid labile subunit, histidine-rich glycoprotein precursor, phospholipid transfer protein isoform a precursor, antithrombin III, glucosamine(N-acetyl)-6-sulfatase precursor, coagulation factor XIII B chain, vitronectin, biotinidase precursor, acid labile subunit, alpha-1-B-glycoprotein, thrombin inhibitor, C9 complement protein, Coagulation factor XIII B chain precursor, hemopexin precursor, vanin 1 precursor, extracellular matrix protein 1 isoform precursor, histidine-rich glycoprotein, dopamine beta-hydroxylase precursor, peptidoglycan recognition protein L precursor, Chain A Crystal Structure of Native Heparin Cofactor Ii, fibrinogen gamma chain, inter-alpha (globulin) inhibitor H1, alpha-2-antiplasmin precursor, vitronectin precursor, Vitamin K-dependent protein S precursor, complement component 9, GRP78, analogs and fragments thereof; and any combination thereof.
In still other embodiments, the control protein expression profile is a late or early stage osteoarthritis expression profile, and the difference is indicative of normal or healthy subject. In such embodiments, the difference may be selected from the group consisting of an increase or decrease in the level of expression of one or more proteins selected from the group consisting of fibronectin precursor, alpha-2-macroglobulin precursor, Chain B Structure of Complement C3b, complement factor H, fibronectin 1 isoform 3 preproprotein, collagen type IV alpha 1, alph 2 type IV collagen preprotein, inter-alpha-trypsin inhibitor, C-terminal inter-alpha trypsin inhibitor, phosphatidylinositol-glycan-specific phospholipase D1, afamin precursor, complement component 6 isoform CRA_b, inter-alpha-trypsin inhibitor heavy chain-related protein, Chain A Crystal Structure of human Galectin-7, COMP, ALB protein, gelsolin isoform a precursor, complement factor B, fibulin-1 isoform D precursor, valosin-containing protein, Vitamin D-binding protein precursor, complement component 2 precursor, annexin A2, Annexin A2 isoform 2, hornerin precursor, complement component 1 subcomponent, ASPIC, Vitamin K-dependent protein, plasma kallikrein precursor, S100 calcium-binding protein A9, Protein S100-A7 (psoriasin), coagulation factor XIII, B Chain Alpha-Ferrous-Carbonmonoxy, coagulation factor II precursor, insulin-like growth factor binding protein acid labile subunit, histidine-rich glycoprotein precursor, phospholipid transfer protein isoform a precursor, antithrombin III, glucosamine(N-acetyl)-6-sulfatase precursor, coagulation factor XIII B chain, vitronectin, biotinidase precursor, acid labile subunit, alpha-1-B-glycoprotein, thrombin inhibitor, C9 complement protein, Coagulation factor XIII B chain precursor, hemopexin precursor, vanin 1 precursor, extracellular matrix protein 1 isoform precursor, histidine-rich glycoprotein, dopamine beta-hydroxylase precursor, peptidoglycan recognition protein L precursor, Chain A Crystal Structure of Native Heparin Cofactor Ii, fibrinogen gamma chain, inter-alpha (globulin) inhibitor H1, alpha-2-antiplasmin precursor, vitronectin precursor, Vitamin K-dependent protein S precursor, complement component 9, GRP78, analogs and fragments thereof; and any combination thereof.
The methods of the invention may be applied to the study of any type of biological samples allowing one or more inventive biomarkers to be assayed. Examples of biological samples include, but are not limited to, urine, blood, blood products, joint fluid, saliva, and synovial fluid. The biological samples used in the practice of the inventive methods of diagnostic may be fresh or frozen samples collected from a subject, or archival samples with known diagnosis, treatment and/or outcome history. Biological samples may be collected by any non-invasive means, such as, for example, by drawing blood from a subject, or using fine needle aspiration or needle biopsy. Alternatively, biological samples may be collected by an invasive method, including, for example, surgical biopsy.
In certain embodiments, the inventive methods are performed on the biological sample itself without or with limited processing of the sample.
In other embodiments, the inventive methods are performed at the single cell level (e.g., isolation of cells from the biological sample). However, in such embodiments, the inventive methods are preferably performed using a sample comprising many cells, where the assay is “averaging” expression over the entire collection of cells present in the sample. Preferably, there is enough of the biological sample to accurately and reliably determine the expression of the set of biomarkers of interest. Multiple biological samples may be taken from the same tissue/body part in order to obtain a representative sampling of the tissue.
In still other embodiments, the inventive methods are performed on a protein extract prepared from the biological sample. Preferably, the protein extract contains the total protein content. However, the methods may also be performed on extracts containing one or more of: membrane proteins, nuclear proteins, and cytosolic proteins. Methods of protein extraction are well known in the art (see, for example “Protein Methods”, D. M. Bollag et al., 2nd Ed., 1996, Wiley-Liss; “Protein Purification Methods: A Practical Approach”, E. L. Harris and S. Angal (Eds.), 1989; “Protein Purification Techniques: A Practical Approach”, S. Roe, 2nd Ed., 2001, Oxford University Press; “Principles and Reactions o/Protein Extraction, Purification, and Characterization”, H. Ahmed, 2005, CRC Press: Boca Raton, Fla.). Numerous different and versatile kits can be used to extract proteins from bodily fluids and tissues, and are commercially available from, for example, BioRad Laboratories (Hercules, Calif.), BD Biosciences Clontech (Mountain View, Calif.), Chemicon International, Inc. (Temecula, Calif.), Calbiochem (San Diego, Calif.), Pierce Biotechnology (Rockford, Ill.), and Invitrogen Corp. (Carlsbad, Calif.). User Guides that describe in great detail the protocol to be followed are usually included in all these kits. Sensitivity, processing time and costs may be different from one kit to another. One of ordinary skill in the art can easily select the kites) most appropriate for a particular situation. After the protein extract has been obtained, the protein concentration of the extract is preferably standardized to a value being the same as that of the control sample in order to allow signals of the protein markers to be quantitated. Such standardization can be made using photometric or spectrometric methods or gel electrophoresis.
In yet other embodiments, the inventive methods are performed on nucleic acid molecules extracted from the biological sample. For example, RNA may be extracted from the sample before analysis. Methods of RNA extraction are well known in the art (see, for example, J. Sambrook et al., “Molecular Cloning: A Laboratory Manual”, 1989, 2nd Ed., Cold Spring Harbor Laboratory Press: Cold Spring Harbor, N.Y.). Most methods of RNA isolation from bodily fluids or tissues are based on the disruption of the tissue in the presence of protein denaturants to quickly and effectively inactivate RNAses. Isolated total RNA may then be further purified from the protein contaminants and concentrated by selective ethanol precipitations, phenol/chloroform extractions followed by isopropanol precipitation or cesium chloride, lithium chloride or cesium trifluoroacetate gradient centrifugations. Kits are also available to extract RNA (i.e., total RNA or mRNA) from bodily fluids or tissues and are commercially available from, for example, Ambion, Inc. (Austin, Tex.), Amersham Biosciences (Piscataway, N.J.), BD Biosciences Clontech (Palo Alto, Calif.), BioRad Laboratories (Hercules, Calif.), GIBCO BRL (Gaithersburg, Md.), and Qiagen, Inc. (Valencia, Calif.).
In certain embodiments, after extraction, mRNA is amplified, and transcribed into cDNA, which can then serve as template for multiple rounds of transcription by the appropriate RNA polymerase. Amplification methods are well known in the art (see, for example, A. R. Kimmel and S. L. Berger, Methods Enzymol. 1987, 152: 307-316; J. Sambrook et al., “Molecular Cloning: A Laboratory Manual”, 1989, 2nd Ed., Cold Spring Harbour Laboratory Press: New York; “Short Protocols in Molecular Biology”, F. M. Ausubel (Ed.), 2002, 5th Ed., John Wiley & Sons; U.S. Pat. Nos. 4,683,195; 4,683,202 and 4,800,159). Reverse transcription reactions may be carried out using non-specific primers, such as an anchored oligo-dT primer, or random sequence primers, or using a target-specific primer complementary to the RNA for each probe being monitored, or using thermostable DNApolymerases (such as avian myeloblastosis virus reverse transcriptase or Moloney murine leukemia virus reverse transcriptase).
The diagnostic methods of the present invention generally involve the determination of expression levels of a plurality (i.e., one or more, e.g., at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, at least 10 or more) of polypeptides in a biological sample obtained from a subject. Determination of protein expression levels in the practice of the inventive methods may be performed by any suitable method (see, for example, E. Harlow and A. Lane, “Antibodies: A Laboratories Manual”, 1988, Cold Spring Harbor Laboratory Cold Spring Harbor, N.Y.).
In general, protein expression levels are determined by contacting a biological sample isolated from a subject with binding agents for one or more of the protein markers; detecting, in the sample, the levels of polypeptides that bind to the binding agents; and comparing the levels of polypeptides in the sample with the levels of polypeptides in a control sample. As used herein, the term “binding agent” refers to an entity such as a polypeptide or antibody that specifically binds to an inventive protein marker. An entity “specifically binds” to a polypeptide if it reacts/interacts at a detectable level with the polypeptide but does not react/interact detectably with peptides containing unrelated sequences or sequences of different polypeptides.
In certain embodiments, the binding agent is a ribosome, with or without a peptide component, an RNA molecule, or a polypeptide (e.g., a polypeptide that comprises a polypeptide sequence of a protein marker, a peptide variant thereof, or a non-peptide mimetic of such a sequence).
In other embodiments, the binding agent is an antibody specific for a protein marker of the invention. Suitable antibodies for use in the methods of the present invention include monoclonal and polyclonal antibodies, immunologically active fragments (e.g., Fab or (Fab)2 fragments), antibody heavy chains, humanized antibodies, antibody light chains, and chimeric antibodies. Antibodies, including monoclonal and polyclonal antibodies, fragments and chimeras, may be prepared using methods known in the art (see, for example, R. G. Mage and E. Lamoyi, in “Monoclonal Antibody Production Techniques and Applications”, 1987, Marcel Dekker, Inc.: New York, pp. 79-97; G. Kohler and C. Milstein, Nature, 1975, 256: 495-497; D. Kozbor et al., J. Immunol. Methods, 1985, 81: 31-42; and R. J. Cote et al., Proc. Natl. Acad. Sci. 1983, 80: 2026-203; R. A. Lerner, Nature, 1982, 299: 593-596; A. C. Nairn et al., Nature, 1982, 299: 734-736; A. J. Czernik et al., Methods Enzymol. 1991, 201: 264-283; A. J. Czernik et al., Neuromethods: Regulatory Protein Modification: Techniques & Protocols, 1997, 30: 219-250; A. J. Czemik et al., NeuroNeuroprotocols, 1995, 6: 56-61; H. Zhang et al., J. Biol. Chem. 2002, 277: 39379-39387; S. L. Morrison et al., Proc. Natl. Acad. Sci., 1984, 81: 6851-6855; M. S. Neuberger et al., Nature, 1984, 312: 604-608; S. Takeda et al., Nature, 1985, 314: 452-454). Antibodies to be used in the methods of the invention can be purified by methods well known in the art (see, for example, S. A. Minden, “Monoclonal Antibody Purification”, 1996, IBC Biomedical Library Series: Southbridge, Mass.). For example, antibodies can be affinity purified by passage over a column to which a protein marker or fragment thereof is bound. The bound antibodies can then be eluted from the column using a buffer with a high salt concentration.
Instead of being prepared, antibodies to be used in the methods of the present invention may be obtained from scientific or commercial sources.
In certain embodiments, the binding agent is directly or indirectly labeled with a detectable moiety. The role of a detectable agent is to facilitate the detection step of the diagnostic method by allowing visualization of the complex formed by binding of the binding agent to the protein marker (or analog or fragment thereof). Preferably, the detectable agent is selected such that it generates a signal which can be measured and whose intensity is related (preferably proportional) to the amount of protein marker present in the sample being analyzed. Methods for labeling biological molecules such as polypeptides and antibodies are well-known in the art (see, for example, “Affinity Techniques. Enzyme Purification. Part B”, Methods in Enzymol., 1974, Vol. 34, W. B. Jakoby and M. Wilneck (Eds.), Academic Press: New York, N.Y.; and M. Wilchek and E. A. Bayer, Anal. Biochem., 1988, 171: 1-32).
Any of a wide variety of detectable agents can be used in the practice of the present invention. Suitable detectable agents include, but are not limited to: various ligands, radionuclides, fluorescent dyes, chemiluminescent agents, microparticles (such as, for example, quantum dots, nanocrystals, phosphors and the like), enzymes (such as, for example, those used in an ELISA, i.e., horseradish peroxidase, beta-galactosidase, luciferase, alkaline phosphatase), colorimetric labels, magnetic labels, and biotin, dioxigenin or other haptens and proteins for which antisera or monoclonal antibodies are available.
In certain embodiments, the binding agents (e.g., antibodies) may be immobilized on a carrier or support (e.g., a bead, a magnetic particle, a latex particle, a microtiter plate well, a cuvette, or other reaction vessel). Examples of suitable carrier or support materials include agarose, cellulose, nitrocellulose, dextran, Sephadex, Sepharose, liposomes, carboxymethyl cellulose, polyacrylamides, polystyrene, gabbros, filter paper, magnetite, ion-exchange resin, plastic film, plastic tube, glass, polyamine-methyl vinylether-maleic acid copolymer, amino acid copolymer, ethylene-maleic acid copolymer, nylon, silk, and the like. Binding agents may be indirectly immobilized using second binding agents specific for the first binding agents (e.g., mouse antibodies specific for the protein markers may be immobilized using sheep anti-mouse IgG Fc fragment specific antibody coated on the carrier or support).
Protein expression levels in the diagnostic methods of the present invention may be determined using immunoassays. Examples of such assays are radioimmunoassays, enzyme immunoassays (e.g., ELISA), immunofluorescence immunoprecipitation, latex agglutination, hemagglutination, and histochemical tests, which are conventional methods well-known in the art. As will be appreciated by one skilled in the art, the immunoassay may be competitive or noncompetitive. Methods of detection and quantification of the signal generated by the complex formed by binding of the binding agent with the protein marker will depend on the nature of the assay and of the detectable moiety (e.g., fluorescent moiety).
Alternatively, the protein expression levels may be determined using mass spectrometry based methods or image (including use of labeled ligand) based methods known in the art for the detection of proteins. Other suitable methods include proteomics-based methods. Proteomics, which studies the global changes of protein expression in a sample, typically includes the following steps: (I) separation of individual proteins in a sample by electrophoresis (2-D PAGE), (2) identification of individual proteins recovered from the gel (e.g., by mass spectrometry or N-terminal sequencing), and (3) analysis of the data using bioinformatics.
As already mentioned above, the diagnostic methods of the present invention may involve determination of the expression levels of a set of nucleic acid molecules comprising polynucleotide sequences coding for an inventive protein marker. Determination of expression levels of nucleic acid molecules in the practice of the inventive methods may be performed by any suitable method, including, but not limited to, Southern analysis, Northern analysis, polymerase chain reaction (PCR) (see, for example, U.S. Pat. Nos. 4,683,195; 4,683,202, and 6,040,166; “PCR Protocols: A Guide to Methods and Applications”, Innis et al. (Eds.), 1990, Academic Press: New York), reverse transcriptase PCR (RT-PCT), anchored PCR, competitive PCR (see, for example, U.S. Pat. No. 5,747,251), rapid amplification of cDNA ends (RACE) (see, for example, “Gene Cloning and Analysis: Current Innovations, 1997, pp. 99-115); ligase chain reaction (LCR) (see, for example, EP 01 320308), one-sided PCR (Ohara et al., Proc. Natl. Acad. Sci., 1989, 86: 5673-5677), in situ hybridization, Taqman based assays (Holland et al., Proc. Natl. Acad. Sci., 1991, 88:7276-7280), differential display (see, for example, Liang et al., Nucl. Acid. Res., 1993, 21: 3269-3275) and other RNA fingerprinting techniques, nucleic acid sequence based amplification (NASBA) and other transcription based amplification systems (see, for example, U.S. Pat. Nos. 5,409,818 and 5,554,527), Qbeta Replicase, Strand Displacement Amplification (SDA), Repair Chain Reaction (RCR), nuclease protection assays, subtraction-based methods, Rapid-Scan™, and the like.
Nucleic acid probes for use in the detection of polynucleotide sequences in biological samples may be constructed using conventional methods known in the art. Suitable probes may be based on nucleic acid sequences encoding at least 5 sequential amino acids from regions of nucleic acids encoding a protein marker, and preferably comprise about 15 to about 50 nucleotides. A nucleic acid probe may be labeled with a detectable moiety, as mentioned above in the case of binding agents. The association between the nucleic acid probe and detectable moiety can be covalent or non-covalent. Detectable moieties can be attached directly to nucleic acid probes or indirectly through a linker (E. S. Mansfield et al., Mol. Cell. Probes, 1995, 9: 145-156). Methods for labeling nucleic acid molecules are well-known in the art (for a review of labeling protocols, label detection techniques and recent developments in the field, see, for example, L. J. Kricka, Ann. Clin. Biochem. 2002, 39: 114-129; R. P. van Gijlswijk et al., Expert Rev. Mol. Diagn. 2001, 1: 81-91; and S. Joos et al., J. Biotechnol. 1994, 35:135-153).
Nucleic acid probes may be used in hybridization techniques to detect polynucleotides encoding the protein markers. The technique generally involves contacting an incubating nucleic acid molecules in a biological sample obtained from a subject with the nucleic acid probes under conditions such that specific hybridization takes place between the nucleic acid probes and the complementary sequences in the nucleic acid molecules. After incubation, the non-hybridized nucleic acids are removed, and the presence and amount of nucleic acids that have hybridized to the probes are detected and quantified.
Detection of nucleic acid molecules comprising polynucleotide sequences coding for a protein marker may involve amplification of specific polynucleotide sequences using an amplification method such as PCR, followed by analysis of the amplified molecules using techniques known in the art. Suitable primers can be routinely designed by one skilled in the art. In order to maximize hybridization under assay conditions, primers and probes employed in the methods of the invention generally have at least 60%, preferably at least 75% and more preferably at least 90% identity to a portion of nucleic acids encoding a protein marker.
Hybridization and amplification techniques described herein may be used to assay qualitative and quantitative aspects of expression of nucleic acid molecules comprising polynucleotide sequences coding for the inventive protein markers.
Alternatively, oligonucleotides or longer fragments derived from nucleic acids encoding each protein marker may be used as targets in a microarray. A number of different array configurations and methods of their production are known to those skilled in the art (see, for example, U.S. Pat. Nos. 5,445,934; 5,532,128; 5,556,752; 5,242,974; 5,384,261; 5,405,783; 5,412,087; 5,424,186; 5,429,807; 5,436,327; 5,472,672; 5,527,681; 5,529,756; 5,545,531; 5,554,501; 5,561,071; 5,571,639; 5,593,839; 5,599,695; 5,624,711; 5,658,734; and 5,700,637). Microarray technology allows for the measurement of the steady-state level of large numbers of polynucleotide sequences simultaneously. Microarrays currently in wide use include cDNA arrays and oligonucleotide arrays. Analyses using microarrays are generally based on measurements of the intensity of the signal received from a labeled probe used to detect a cDNA sequence from the sample that hybridizes to a nucleic acid probe immobilized at a known location on the microarray (see, for example, U.S. Pat. Nos. 6,004,755; 6,218,114; 6,218,122; and 6,271,002). Array-based gene expression methods are known in the art and have been described in numerous scientific publications as well as in patents (see, for example, M. Schena et al., Science, 1995, 270: 467-470; M. Schena et al., Proc. Natl. Acad. Sci. USA 1996, 93: 10614-10619; 1. 1. Chen et al., Genomics, 1998, 51: 313324; U.S. Pat. Nos. 5,143,854; 5,445,934; 5,807,522; 5,837,832; 6,040,138; 6,045,996; 6,284,460; and 6,607,885).
Once the expression levels of the biomarkers of interest have been determined (as described above) for the biological sample being analyzed, they are compared to the expression levels in one or more control samples or to at least one expression profile map for OA. Comparison of expression levels according to methods of the present invention is preferably performed after the expression levels obtained have been corrected for both differences in the amount of sample assayed and variability in the quality of the sample used (e.g., amount of protein extracted, or amount and quality of mRNA tested). Correction may be carried out using different methods well-known in the art. For example, the protein concentration of a sample may be standardized using photometric or spectrometric methods or gel electrophoresis (as already mentioned above) before the sample is analyzed. In case of samples containing nucleic acid molecules, correction may be carried out by normalizing the levels against reference genes (e.g., housekeeping genes) in the same sample. Alternatively or additionally, normalization can be based on the mean or median signal (e.g., Ct in the case of RT-PCR) of all assayed genes or a large subset thereof (global normalization approach).
For a given set of biomarkers, comparison of an expression pattern obtained for a biological sample against an expression profile map established for a particular stage of OA may comprise comparison of the normalized expression levels on a biomarker-by-biomarker basis and/or comparison of ratios of expression levels within the set of biomarkers. In addition, the expression pattern obtained for the biological sample being analyzed, may be compared against each of the expression profile maps (e.g., expression profile map for non-OA, expression profile map for OA, expression profile map for early OA, and expression profile map for late OA) or against an expression profile that defines delineations made based upon all the OA expression profile maps.
Using methods described herein, skilled physicians may select and prescribe treatments adapted to each individual patient based on the diagnosis and disease staging provided to the patient through determination of the expression levels of the inventive biomarkers. In particular, the present invention provides physicians with a non-subjective means to diagnose early OA, which will allow for early treatment, when intervention is likely to have its greatest effect, potentially preventing pain and long-term disability and improving patient's quality of life. Selection of an appropriate therapeutic regimen for a given patient may be made based solely on the diagnosis/staging provided by the inventive methods. Alternatively, the physician may also consider other clinical or pathological parameters used in existing methods to diagnose OA and assess its advancement.
Furthermore, the methods of OA diagnosis and OA staging provided by the present invention allow the disease to be monitored even when signs of cartilage destruction would not be visible or when changes in joint spaces would not be detectable on X-ray images.
In another aspect, the present invention provides kits comprising materials useful for carrying out diagnostic methods according to the present invention. The diagnosis and staging procedures described herein may be performed by diagnostic laboratories, experimental laboratories, or practitioners. The invention provides kits, which can be used in these different settings.
Materials and reagents for characterizing biological samples, diagnosing OA in a subject, and/or staging OA in a subject according to the inventive methods may be assembled together in a kit. In certain embodiments, an inventive kit comprises at least one reagent that specifically detects expression levels of one or more inventive biomarkers, and instructions for using the kit according to a method of the invention. Each kit may preferably include the reagent, which renders the procedure specific. Thus, for detecting/quantifying a protein marker (or an analog or fragment thereof), the reagent that specifically detects expression levels of the protein may be an antibody that specifically binds to the protein marker (or analog or fragment thereof). For detecting/quantifying a nucleic acid molecule comprising a polynucleotide sequence coding a protein marker, the reagent that specifically detects expression levels may be a nucleic acid probe complementary to the polynucleotide sequence (e.g., cDNA or an oligonucleotide). The nucleic acid probe may or may not be immobilized on a substrate surface (e.g., beads, a microarray, and the like).
Depending on the procedure, the kit may further comprise one or more of, extraction buffer and/or reagents, amplification buffer and/or reagents, hybridization buffer and/or reagents, immunodetection buffer and/or reagents, labeling buffer and/or reagents, and detection means. Protocols for using these buffers and reagents for performing different steps of the procedure may be included in the kit.
The reagents may be supplied in a solid (e.g., lyophilized) or liquid form. The kits of the present invention may optionally comprise different containers (e.g., vial, ampoule, test tube, flask or bottle) for each individual buffer and/or reagent. Each component will generally be suitable as aliquoted in its respective container or provided in a concentrated form. Other containers suitable for conducting certain steps of the disclosed methods may also be provided. The individual containers of the kit are preferably maintained in close confinement for commercial sale.
In certain embodiments, the kits of the present invention further comprise control samples. In other embodiments, the inventive kits comprise at least one expression profile map for OA and/or OA progression as described herein for use as comparison template. Preferably, the expression profile map is digital information stored in a computer-readable medium.
Instructions for using the kit, according to one or more methods of the invention, may comprise instructions for processing the biological sample obtained from the subject, and/or for performing the test, instructions for interpreting the results. As well as a notice in the form prescribed by a governmental agency (e.g., FDA) regulating the manufacture, use or sale of pharmaceuticals or biological products.
As noted above, the inventive biomarkers whose expression profiles correlate with osteoarthritis and/or osteoarthritis progression are attractive targets for the identification of new therapeutic agents (e.g., using screens to detect compounds or substances that inhibit or enhance the expression of these biomarkers). Accordingly, the present invention provides methods for the identification of compounds potentially useful for treating osteoarthritis or modulating osteoarthritis progression.
The inventive methods comprise incubating a biological system, which expresses at least one inventive biomarker, with a candidate compound under conditions and for a time sufficient for the candidate compound to modulate the expression of the biomarker, thereby obtaining a test system; incubating the biological system under the same conditions and for the same time absent the candidate compound, thereby obtaining a control system; measuring the expression level of the biomarker in the test system; measuring the expression level of the biomarker in the control system; and determining that the candidate compound modulates the expression of the biomarker if the expression level measured in the test system is less than or greater than the expression level measured in the control system.
The assay and screening methods of the present invention may be carried out using any type of biological systems, e.g., a cell or cells, a biological fluid, a biological tissue, or an animal. In certain embodiments, the methods are carried out using a system that can exhibit cartilage degeneration due to OA (e.g., an animal model, or whole or portion of a body part, e.g., the knee). In other embodiments, the methods are carried out using a biological entity that expresses or comprises at least one inventive biomarker (e.g., a cell or a sample of blood, urine, saliva, or synovial fluid).
In certain preferred embodiments, the assay and screening methods of the present invention are carried out using cells that can be grown in standard tissue culture plastic ware. Such cells include all appropriate normal and transformed cells derived from any recognized sources. Preferably, cells are of mammalian (human or animal, such as rodent or simian) origin. More preferably, cells are of human origin. Mammalian cells may be of any organ or tissue origin (e.g., bone, cartilage, or synovial fluid) and of any cell types as long as the cells express at least one inventive biomarker.
Cells to be used in the practice of the methods of the present invention may be primary cells, secondary cells, or immortalized cells (e.g., established cell lines). They may be prepared by techniques well known in the art (for example, cells may be isolated from bone, cartilage or synovial fluid) or purchased from immunological and microbiological commercial resources (for example, from the American Type Culture Collection, Manassas, Va.). Alternatively or additionally, cells may be genetically engineered to contain, for example, a gene of interest.
Selection of a particular cell type and/or cell line to perform an assay according to the present invention will be governed by several factors such as the nature of the biomarker whose expression is to be modulated and the intended purpose of the assay. For example, an assay developed for primary drug screening (i.e., first round(s) of screening) is preferably performed using established cell lines, which are commercially available and usually relatively easy to grow, while an assay to be used later in the drug development process is preferably performed using primary and secondary cells, which are generally more difficult to obtain, maintain and/or grow than immortalized cells but which represent better experimental models for in vivo situation. Examples of established cell lines that can be used in the practice of the assay and screening methods of the present invention include fibroblastic and/or osseously derived cell lines. Primary and secondary cells that can be used in the inventive screening methods include, but are not limited to, chondrocytes and osteocytes.
Cells to be used in the inventive assays may be cultured according to standard cell culture techniques. For example, cells are often grown in a suitable vessel in a sterile environment at 37° C. in an incubator containing a humidified 95% air-5% CO2 atmosphere. Vessels may contain stirred or stationary cultures. Various cell culture media may be used including media containing undefined biological fluids such as fetal calf serum. Cell culture techniques are well known in the art and established protocols are available for the culture of diverse cell types (see, for example, R. I. Freshney, “Culture of Animal Cells: A Manual of Basic Technique”, 2nd Edition, 1987, Alan R. Liss, Inc.).
In certain embodiments, the screening methods are performed using cells contained in a plurality of wells of a multi-well assay plate. Such assay plates are commercially available, for example, from Stratagene Corp. (La Jolla, Calif.) and Coming Inc. (Acton, Mass.) and include, for example, 48-well, 96-well, 384-well and 1536-well plates.
As will be appreciated by those of ordinary skill in the art, any kind of compounds or agents can be tested using the inventive methods. A candidate compound may be a synthetic or natural compound; it may be a single molecule or a mixture or complex of different molecules. In certain embodiments, the inventive methods are used for testing one or more compounds. In other embodiments, the inventive methods are used for screening collections or libraries of compounds. As used herein, the term “collection” refers to any set of compounds, molecules or agents, while the term “library” refers to any set of compounds, molecules or agents that are structural analogs.
Collections of natural compounds in the form of bacterial, fungal, plant and animal extracts are available from, for example, Pan Laboratories (Bothell, Wash.) or MycoSearch (Durham, N.C.). Libraries of candidate compounds that can be screened using the methods of the present invention may be either prepared or purchased from a number of companies. Synthetic compound libraries are commercially available from, for example, Comgenex (Princeton, N.J.), Brandon Associates (Merrimack, N.H.), Microsource (New Milford, Conn.), and Aldrich (Milwaukee, Wis.). Libraries of candidate compounds have also been developed by and are commercially available from large chemical companies, including, for example, Merck, Glaxo Welcome, Bristol-Meyers-Squibb, Novartis, Monsanto/Searle, and Pharmacia UpJohn. Additionally, natural collections, synthetically produced libraries and compounds are readily modified through conventional chemical, physical, and biochemical means. Chemical libraries are relatively easy to prepare by traditional automated synthesis, PCR, cloning or proprietary synthetic methods (see, for example, S. H. DeWitt et al., Proc. Natl. Acad. Sci. U.S.A. 1993, 90:6909-6913; R. N. Zuckermann et al., J. Med. Chem. 1994, 37: 2678-2685; Carell et al., Angew. Chem. Int. Ed. Engl. 1994, 33: 2059-2060; P. L. Myers, Curro Opin. Biotechnol. 1997, 8: 701-707).
Useful agents for the treatment of osteoarthritis may be found within a large variety of classes of chemicals, including heterocycles, peptides, saccharides, steroids, and the like. In certain embodiments, the screening methods of the invention are used for identifying compounds or agents that are small molecules (i.e., compounds or agents with a molecular weight <600-700 Da).
The screening of libraries according to the inventive methods will provide “hits” or “leads”, i.e., compounds that possess a desired but not-optimized biological activity. The next step in the development of useful drug candidates is usually the analysis of the relationship between the chemical structure of a hit compound and its biological or pharmacological activity. Molecular structure and biological activity are correlated by observing the results of systemic structural modification on defined biological end-points. Structure-activity relationship information available from the first round of screening can then be used to generate small secondary libraries, which are subsequently screened for compounds with higher affinity. The process of performing synthetic modifications of a biologically active compound to fulfill all stereoelectronic, physicochemical, pharmacokinetic, and toxicologic factors required for clinical usefulness is called lead optimization. Candidate compounds identified as potential OA therapeutic agents by screening methods of the present invention can similarly be subjected to a structure-activity relationship analysis, and chemically modified to provide improved drug candidates. The present invention also encompasses these improved drug candidates.
In the screening methods of the present invention, a candidate compound is identified as a modulator of the expression of at least one inventive biomarker if the expression level of the biomarker in the test sample is lower or greater than the expression level of the same biomarker in the control sample. Reproducibility of the results obtained using methods of the present invention may be tested by performing the analysis more than once with the same concentration of the same candidate compound (for example, by incubating cells in more than one well of an assay plate). Additionally, since candidate compounds may be effective at varying concentrations depending on the nature of the compound and the nature of its mechanism(s) of action, varying concentrations of the candidate compound may be tested (for example, by addition of different concentrations of the candidate compound in different wells containing cells in an assay plate). Generally, candidate compound concentrations from about 1 μM to about 10 mM are used for screening. Preferred screening concentrations are between about 10 μM and about 100 μM.
In certain embodiments, the methods of the invention further involve the use of one or more negative or positive control compounds. A positive control compound may be any molecule or agent that is known to modulate the expression of at least one biomarker studied in the screening assay. A negative control compound may be any molecule or agent that is known to have no detectable effects on the expression of at least one biomarker studied in the screening assay. In these embodiments, the inventive methods further comprise comparing the modulating effects of the candidate compound to the modulating effects (or absence thereof) of the positive (or negative) control compound.
As will be appreciated by those skilled in the art, it is generally desirable to further characterize the compounds identified by the inventive screening methods. For example, if a candidate compound has been identified as a modulator of the expression of a specific biomarker in a given cell culture system (e.g., an established cell line), it may be desirable to test this ability in a different cell culture system (e.g., primary or secondary cells). Alternatively or additionally, it may be desirable to evaluate the effects of the candidate compound on the expression of one or more other inventive biomarkers. It may also be desirable to perform pharmacokinetics and toxicology studies.
A candidate compound identified by the screening methods of the invention may also be further tested in assays that allow for the determination of the compound's properties in vivo. Suitable animal models of osteoarthritis are known in the art. In general, these models fall into two categories, spontaneous and induced (surgical instability or genetic manipulation). Animal models of naturally occurring OA occur in knee joints of guinea pigs, mice, and Syrian hamsters. Commonly used surgical instability models include medial meniscal tear in guinea pigs and rats, medial or lateral partial meniscectomy in rabbits, medial partial or total meniscectomy or anterior cruciate transection in dogs. Transgenic models have been developed in mice. Examples of animal models of osteoarthritis suitable for testing the candidate compounds identified as potential OA therapeutic agents include, but are not limited to, those described in M. J. Pond and G. Nuki, Ann. Rheum. Dis., 1973, 32: 387-388; T. Videman, Acta Orthop. Scand., 1982, 53: 339-347; S. B. Christensen, Scand. J. Rheumatol., 1983, 12: 343-349; A. M. Bendele et al., Vet. Pathol., 1987, 24: 436-443; K. D. Brandt et al., J. Rheumatol., 1991, 18: 436-446; K. D. Brandt, Ann. NY Acad. Sci., 1994, 732: 199-205; C. S. Carlson et al., J. Orthop. Res., 1994, 12: 331-339; A. G. Fam et al., Arthritis Rheum., 1995, 38: 201-210; K. W. Marshall and A. D. Chan, J. Rheumatol., 1996, 23: 344-350; H. J. Helminen et al., Rheumatol., 2002, 41: 848-856 and references cited therein; and J. L. Henry, Novartis Found Symp., 2004, 260: 139-145.
The present invention also provides pharmaceutical compositions, which comprise, as active ingredient, an effective amount of at least one compound identified by an inventive screening assay as a modulator of the expression of at least one biomarker or one set of biomarkers disclosed herein. The pharmaceutical composition may be formulated using conventional methods well known in the art. Such compositions include, in addition to the active ingredient(s), at least one pharmaceutically acceptable liquid, semi-liquid, or solid diluent acting as pharmaceutical vehicle, excipient or medium, and termed here “pharmaceutically acceptable carrier”.
According to the present invention, an inventive pharmaceutical composition may include one or more OA therapeutic agents of the invention as active ingredients. Alternatively, a pharmaceutical composition containing an effective amount of one OA therapeutic agent may be administered to a patient simultaneously with or sequentially with a pharmaceutical composition containing a different inventive OA therapeutic agent.
In another embodiment of this invention, an inventive OA therapeutic agent, or a pharmaceutical composition thereof, may be administered serially or in combination with conventional therapeutics used in the treatment of OA. Such therapeutics include pain relievers such as acetaminophen; Non-steroidal Anti-inflammatory Drugs (NSAIDs), such as aspirin, ibuprofen, naproxen, and ketoprofen; COX-2 inhibitors; corticosteroids; combination of supplement glucosamine and chondroitin sulfates; and over the counter topical formulations containing capsaicin.
Alternatively or additionally, an inventive OA therapeutic agent, or a pharmaceutical composition thereof, may be administered serially or in combination with conventional therapeutic regimens for the treatment of osteoarthritis including viscosupplementation, surgery, arthroplasty (or joint replacement surgery), arthrodesis (or joint fusion), osteotomy, arthroscopy and cartilage transplantation.
In another aspect, the present invention provides methods for the treatment and/or prevention of osteoarthritis. These methods comprise administering to a subject afflicted with OA, an effective amount of a compound that modulates the expression of at least one inventive biomarker. The compound may be known in the art to act as a modulator of the expression of the at least one biomarker. Alternatively, the compound may have been identified as an OA therapeutic agent by a screening method provided by the present invention.
Subjects suitable to receive a treatment according to the present invention include individuals that have been diagnosed with OA using conventional methods (e.g., radiological examination, clinical observations) as well as individuals that have been diagnosed with OA using diagnostic methods provided herein. Suitable subjects may or may not have previously received traditional treatment for the condition.
A treatment according to the methods of the present invention may consist of a single dose or a plurality of doses over a period of time. An inventive OA therapeutic agent, or pharmaceutical composition thereof, may also be released from a depot form per treatment. The administration may be carried out in any convenient manner such as by injection (subcutaneous, intravenous, intramuscular, intraperitoneal, or the like), oral administration, topical administration, rectal administration, or sublingual administration.
Effective dosages and administration regimens can be readily determined by good medical practice and the clinical condition of the individual patient. The frequency of administration will depend on the pharmacokinetic parameters of the active ingredient(s) and the route of administration. The optimal pharmaceutical formulation can be determined depending upon the route of administration and desired dosage. Such formulations may influence the physical state, stability, rate of in vivo release, and rate of in vivo clearance of the administered compounds.
Depending on the route of administration, a suitable dose may be calculated according to body weight, body surface area, or organ size. Optimization of the appropriate dosage can readily be made by those skilled in the art in light of pharmacokinetic data observed in human clinical trials. The final dosage regimen will be determined by the attending physician, considering various factors which modify the action of drugs, e.g., the drug's specific activity, the severity of the damage and the responsiveness of the patient, the age, condition, body weight, sex and diet of the patient, the severity of any present infection, time of administration and other clinical factors. As studies are conducted, further information will emerge regarding the appropriate dosage levels and duration of treatment for various stages of advancement of OA.
A previous study, using mass spectroscopy-based proteomic techniques in synovial fluid (SF), had identified candidate biomarkers for OA with potential to be developed as highly sensitive and specific tests for disease diagnosis. In this study, patients with OA or healthy controls had their SF fractionated using 1 dimensional SDS gels, gel bands were excised and proteins identified and quantified using mass spectrometry for OA versus control. Due to the complex nature of the SF, this technology has limited ability to identify a larger number of potential biomarkers, and in fact can be expected to be able to sift through only the top 100-200 proteins in the sample. In particular, SF contains many serum proteins that mask information relevant to the disease that could be derived from the diseased synovial tissue. Also, the analytical methods used that compared LC-MS intensities of peptides derived from gel bands in the 1-D gel analysis were not optimal for discerning significant differences, specifically they lacked accurate mass tag information.
In this study, we added a number of novel features to provide more accurate quantification and advanced statistical techniques for determining significance. We increased separation of the protein components in the sample, included a third patient group, that of early OA, and age-matched the samples. We first subjected the SF to immuno-affinity depletion to remove abundant components that are derived from admixture of synovial fluid with serum. This was intended to emphasize the contribution of proteins in the SF preparation that are differentially regulated in diseased versus normal synovial tissue. Second, instead of fractionating the proteins by a 1-D gel method, we used a 2-dimensional method that fractionates the protein by both size and charge. Coupled to the large format gels available, typically 2000-3000 protein forms can be examined for abundance variation. Third, the SF proteins were labeled with fluorescent dyes and samples from multiple groups were run on the same gel to enhance the use of modem statistical methods to examine group based differences with high confidence.
In short, we identified biomarkers in the SF of early OA and late OA patients (versus healthy controls) using Two Dimensional Fluorescence Difference Gel Electrophoresis (2D-DIGE) coupled with mass spectroscopy. Using this method, a variety of alterations that describe the progressive nature of the disease were discovered and potential candidate biomarkers for OA had been found suitable for diagnostic purposes or for evaluating therapeutic response.
Patients with Early Osteoarthritis, Late Osteoarthritis and Controls
Two separate 2D DIGE experiments with different numbers of subjects were performed in this study. In the first experiment, 4 healthy control individuals with same number of patients diagnosed with early and late OA were identified and provided SF samples (12 patients). As stated in a previous study, all samples were collected within our tertiary care referral center and approved by our hospital's institutional review board. All SF samples were snap-frozen in liquid nitrogen immediately after acquisition from the knee joint. In the second experiment, we increased the sample size to 6 controls and same number of patients diagnosed with early and late OA (18 total).
Immuno-affinity depletion was performed for all human synovial fluid samples to remove high. abundant proteins using a commercial column from Agilent. The proteins samples were then further cleaned (GE Healthcare Clean-Up kit), and protein concentration was determined using the 2D-Quant kit as described by the manufacturer (GE Healthcare). Twelve aliquots from each sample with 25 micrograms of proteins were pooled together to prepare an internal standard.
Precast immobilized pH gradient strips (pH 3-10 NL, 24 cm) were used for isoelectric focusing and IEF was carried out on an IPGphor2 system (GE Healthcare). The proteins were separated by their pI and the strips were transferred for 2nd dimension SDS-PAGE, which separated the proteins by their molecular weight. After electrophoresis the spots labeled by Cydye in the gel were visualized using the Typhoon 9400 imager (GE Healthcare).
To compare protein spots across all gels, image analyses were conducted using DeCyder v6.5 2D Differential Analysis Software (GE Healthcare). Protein spot detection and quantification on a set of images was performed using Differential In•gel Analysis (DIA) module in DeCyder software. Because the internal standard was the same pooled sample within each gel, this effectively normalized all the data. Then images were loaded into the biological variation analysis (BVA) module, which matched multiple images from different gels to perform statistical analysis on differential protein expression levels between multiple groups.
Differences in protein abundance among the three groups (Healthy, EOA and LOA) were evaluated by a one-way analysis of variance (ANOVA) considered significant at p value <0.05. Gel spots were digested by an automatic in-gel digestion system in 96-well plate and mass spectrometry analysis of the peptide for protein identification was performed on a Finnigan LTQ FT hybrid mass spectrometer (Thermo Electron Corp.).
All MSIMS data derived from the IT instrument above were analyzed using Mascot Daemon (Matrix Science; version 2.2.1) using an indexed Homo sapiens (human) subset database (191437 sequences) created from the National Center for Biotechnology Information (NCBInr) non-redundant databases containing 4626804 sequences assuming the digestion enzyme as trypsin. Search parameters used in this study were: 1) fragment ion mass tolerance of 0.80 Da and peptide mass tolerance limits of 15 ppm, 2) Iodoacetamide derivative of cysteine was specified as a fixed modification (57 Da) and oxidation of methionine was specified as a variable modification (16 Da), 3) One missed cleavage site was allowed, 4) Peptide identifications were accepted at a cut off of p value as 0.05. A positive identification was accepted when a minimum of two peptide monoisotopic masses matched a particular protein with low expectation value (p<0.001).
Decyder software identified the following protein spot numbers (in bold type) as differentially expressed between Early Osteoarthritic (EOA) and Late Osteoarthritic (LOA). Listed below each protein spot number are the potential proteins that each protein spot number represents identified by Mascot search software. The criteria used to determine the results listed below include, Mr, PI, and sequence coverage. These criteria were compared between Mascot search results and Decyder image analysis. These results are listed in Appendix A which includes Tables 1-6.
Other embodiments of the invention will be apparent to those skilled in the art from a consideration of the specification or practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope of the invention being indicated by the following claims. All patents, publication, and referenced cited are incorporated by reference in their entirety.
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This application claims priority from U.S. Provisional Application No. 61/146,524, filed Jan. 22, 2009, the subject matter, which is incorporated herein by reference.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US10/21741 | 1/22/2010 | WO | 00 | 2/2/2012 |
Number | Date | Country | |
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61146524 | Jan 2009 | US |