Patent Application
20230313182
The disclosure relates to field of molecular medicine and diagnosis, prevention and treatment of metabolic diseases, and more particularly to a method for preparing a kit for early warning and/or diagnosing diabetes, and a drug for preventing and treating diabetes based on hsa-miR-320a and its screening method as well as preparation method thereof.
MicroRNA (miRNA, miR) is a newly discovered class of endogenous small non-coding single stranded RNA with a length about 22 nucleotides which is from endogenous hairpin structure transcript. MicroRNA regulate gene expression after transcription by specifically binding to 3′untranslated region (3′untranslated region, 3′UTR) of target mRNA to promote degradation of target mRNA or inhibit translation of target gene and reduce coding protein level. miRNA is associated with various diseases, including neurodegenerative diseases, heart diseases, kidney diseases and tumor, etc. Recent studies have found that miRNA plays an important role in regulation of glucose and lipid metabolism and insulin resistance.
Diabetes mellitus (DM) is a major disease that seriously threatens human life and health, and its prevalence rate is about 4.4% to 17.9% globally at present, which brings a heavy burden to patients and society. According to epidemiological statistics, the number of diabetes patients in the world reached 370 million in 2011, 80% of which were in developing countries. A total of 4.6 million people died of diabetes in the world that year, and the medical cost of diabetes in the world of that year reached 465 billion US dollars. In China, prevalence rate of diabetes has increased significantly in past 30 years. In 2013, the latest epidemiological survey warned that prevalence rate of diabetes among Chinese adults was 11.6% (about 110 million), and prevalence rate of prediabetes was as high as 50.1% (about 490 million).
More than 90% of diabetes patients are type 2 diabetes mellitus, which is a severe disorder of glycolipid metabolism caused by insulin resistance and p-cell failure and eventually leads to heart cerebrovascular and kidney complications and even death. Previous studies have shown that insulin resistance is a disorder of glycolipid metabolism caused by interaction of various genetic and environmental factors, including defective insulin signaling pathway, abnormal expression of insulin target and cross action of other hormone systems, and imbalance of other metabolic pathways. However, its specific pathophysiological mechanism and molecular signaling network are far from being fully understood and elucidated. Previously, pharmacotherapy strategies for diabetes have been mainly based on correcting glycolipid metabolism disorders, including drugs that promote insulin secretion (sulfonylureas, glinides, DPP-4 inhibitors) and hypoglycemic drugs through other mechanisms (biguanides, TZDs, α-glycosidase inhibitors). Even if patients receive treatment including insulin injection, only 40% of patients have good blood glucose control, and the metabolic disorders caused by diabetes cannot be effectively corrected. Therefore, new treatment measures are urgently needed. On the other hand, etiology and risk factors of diabetes have not been fully elucidated, so it is necessary to find new risk factors and adopt more effective risk assessment methods.
As an important endogenous regulatory factor, miRNAs are widely involved in regulation of signal transduction pathways in animals and plants. Although regulatory mechanism of miRNA has not been fully elucidated, existing research data indicate that miRNA plays an important role in regulation of glycolipid metabolism, which can not only serve as a new diagnostic marker of diabetes, but also participate in regulation of occurrence and development of diabetic insulin resistance and its complications. A series of studies have found significant differences in miRNA expression profiles in peripheral blood of diabetic patients compared with control population. miRNA-375 is specifically expressed in langerhans' islet β cells and participates in regulating secretion of insulin through the PI3K/PDK1/PKB signal pathway, while miR-375 knockout mice showed a glycolipid metabolism disorder phenotype. High systemic or islet specific let-7b expression results in impaired glucose tolerance and reduced insulin secretion. miR-503 expression is increased in endothelial cells under high glucose and is involved in regulation of diabetic vascular function through mediated by Cdc25A and CCNE1.
RNA interference technology is a promising biotechnology with breakthrough clinical application. In just a few years from its inception, several products have entered clinical trials and achieved great success. As disclosed in Chinese invention patent 201210069179.7, in previous research work, applicant of the invention found that miR-320a has a predictive role in atherosclerotic diseases, and studied to confirm the therapeutic role of anti-miR-320a, an antisense sequence of miR-320a, in atherosclerotic diseases. However, relationship between miR-320a and diabetes has not been found in this field, and the existing technologies lack effective products or drugs in molecular diagnosis and molecular therapy of diabetes.
Based on above gaps and requirements in this field, the disclosure further confirms the role of miR-320a in risk prediction of diabetes disease based on original basic work, the role of miR-320a participating in regulation of glucose metabolism and development of diabetes, and the therapeutic role of anti-miR-320a in diabetes. The disclosure provides a novel medicinal use of endogenous non-coding small RNA, more specifically involving microRNA-320a (hsa-miR-320a) and its antisense nucleotide sequence hsa-anti-miR-320a in risk evaluation, prevention and treatment of diabetes mellitus. The invention also relates to the construction of a recombinant adeno-associated virus recombinant (rAAV-miR-320a/rAAV-anti-miR-320a) and its preparation method thereof. More specifically, it's related to cloning of hsa-miR-320a and anti-sense sequence anti-hsa-miR-320a and packaging and preparation of recombinant adeno-associated virus containing hsa-miR-320a and anti-hsa-miR-320a, respectively, and use of the recombinant adeno-associated virus in pharmaco.
The technical solution of the disclosure is as follows:
On the one hand, the disclosure provides a biomarker for the diagnosing and/or early warning diabetes. The biomarker comprises a sequence fragment containing hsa-miR-320a; the hsa-miR-320a is shown as SEQ ID NO: 1.
The biomarker comprises the hsa-miR-320a.
The biomarker is the hsa-miR-320a.
In the 2nd aspect, this invention provides a kit for diagnosing and/or early warning diabetes; the kit comprises a reagent for quantitative detection of the biomarker.
The kit comprises a reagent for quantitative detection of hsa-miR-320a.
The reagent for quantitative detection of hsa-miR-320a comprises a specific primer pairs for hsa-miR-320a.
The specific primer pairs are commercially-available MIRQ0000510-1-1. The primer product is purchased from Guangzhou Ribo Biotechnology Company Limited.
The regents for quantitative detection of hsa-miR-320a also comprises reverse transcription reagents; and/or reverse transcription PCR reagents;
preferably, the reverse transcription reagent comprises: RT Primer Mix, 2×TS reaction buffer, RNase free H2O, TS enzyme;
further preferably, the reverse transcription PCR reagent comprises: 2×SYBR Green Mix, RNase free H2O.
The quantitative detection refers to fluorescent quantitative PCR detection;
most preferably, the kit comprises miR-320a RT-primers, miR-320a real-time PCR forward primers, miR-320a real-time PCR reverse primers, SYBR Green I, TS reaction enzyme, TS reaction buffer and DEPC ddH2O.
In the 3rd aspect, this invention provides Use of the biomarker in preparing reagent for diagnosing diabetes.
In the 4th aspect, this invention provides a drug for preventing and treating diabetes; an active pharmaceutical ingredient of the drug is taking hsa-miR-320a as drug target, and efficacy of preventing and treating diabetes is achieved by binding, and/or capturing, and/or degrading hsa-miR-320a, and/or down-regulating expression of hsa-miR-320a; The hsa-miR-320a is shown as SEQ ID NO: 1.
The active pharmaceutical ingredient of the drug comprises: a substance that can degrade hsa-miR-320a and/or down-regulate expression of hsa-miR-320a;
preferably, the active pharmaceutical ingredient of the drug is a substance that can down-regulate expression of the hsa-miR-320a.
The active pharmaceutical ingredient of the drug comprises: a sequence fragment anti-hsa-miR-320a that is antisense complementary to hsa-miR-320a;
preferably, the antisense complementary refers to that length of the anti-hsa-miR-320a reverse complementary to full-length or partial sequence of the hsa-miR-320a is a sequence fragment of 15-25 bases.
The active pharmaceutical ingredient of the drug is a recombinant plasmid expressing the sequence fragment anti-hsa-miR-320a that is antisense complementary to hsa-miR-320a.
The active pharmaceutical ingredient of the drug is a recombinant adeno-associated virus plasmid pAAV-D(+)-anti-hsa-miR-320a, by which expressed sequence fragment anti-hsa-miR-320a is antisense complementary to hsa-miR-320a;
more specifically, the pAAV-D(+)-anti-miR-320a is constructed by inserting fragment amplified through primer pairs with sequences shown as SEQ ID NO: 4 and SEQ ID NO: 5 into an adenovirus expression vector pAAV-D(+).
The drug also comprises pharmaceutically acceptable excipients and/or reagents for buffering, culturing and/or amplifying the recombinant adeno-associated virus plasmid pAAV-D(+)-anti-miR-320a.
In the 5th of aspect, this invention provides a method of screening drug for preventing and treating diabetes, characterized in that, detecting whether candidate substance can bind, capture and degrade hsa-miR-320a and/or down regulate expression;
preferably, substance that can reduce expression level of hsa-miR-320a is screened.
In the 6th of aspect, this invention provides a method for preparing a drug for preventing and treating diabetes, characterized in that, comprises: taking substance that degrade hsa-miR-320a or down-regulate expression of hsa-miR-320a; sequence fragment anti-hsa-miR-320a antisense complementary to hsa-miR-320a;
The method also comprises: primer pairs expressing sequence fragment anti-hsa-miR-320a antisense complementary to hsa-miR-320a is inserted into expression vector to prepare recombinant plasmid stably expressing sequence fragment anti-hsa-miR-320a antisense complementary to hsa-miR-320a.
Primer pairs which can express the sequence fragment of anti-hsa-miR-320a antisense complementary to hsa-miR-320a are shown as SEQ ID NO: 4 and SEQ ID NO: 5;
Inventor of this invention found by a lot of experiments that expression of hsa-miR-320a in peripheral blood of diabetic patients was significantly increased. Furthermore, the inventor designed and synthesized sequences that express hsa-miR-320a and are antisense complementary to anti-hsa-miR-320a respectively according to hsa-miR-320a base sequence. The sequences are respectively inserted into eukaryotic expression vector pAAV-D (+) to successfully construct a recombinant plasmids pAAV-D (+)-miR-320a and pAAV-D (+)-anti-miR-320a. After that, the following three plasmids were added: 1) pXX2, pXX8 or pXX9, 2) phelper, 3) pAAV-D(+)-miR-320a or pAAV-D(+)-anti-miR-320a were transformed into 293 cells by calcium and phosphorus co-transfection method to package and prepare three serotypes of recombinant adeno-associated viruses (rAAV2, rAAV8 and rAAV9) expressing hsa-miR-320a and antisense complementary anti-hsa-miR-320a respectively. After purification, titer was determined by real-time PCR. Next, two packaged recombinant adeno-associated viruses of same serotype (rAAV-miR-320a and rAAV-anti-miR-320a) were injected into db/db mice via tail vein injection respectively. It was found that blood glucose was significantly regulated in db/db mice, and recombinant adeno-associated virus mediated expression of anti-hsa-miR-320a significantly improved elevated blood glucose and cardiac function in db/db mice. While hsa-miR-320a further aggravated hyperglycemia and heart function in db/db mice. These results further support the therapeutic effect of anti-hsa-miR-320a on diabetes mellitus and its complications.
Specifically, the 1st purpose of the disclosure is to provide expression of miR-320a in peripheral blood of diabetic patients. The results show that expression of miR-320a in peripheral blood of diabetic patients was significantly increased, which suggests that miR-320a can be used as a biomarker for early diagnosing and predicting diabetes.
The second purpose of the disclosure is to confirm the protective effect of anti-miR-320a on diabetes through experiments based on the first purpose, anti-miR-320a can be used as a medicine to treat diabetes and its complications.
In conclusion, hsa-miR-320a discovered in the disclosure can be used as an effective biomarker to evaluate risk of diabetes and to diagnose diabetes. The hsa-miR-320a-based kit is a highly efficient and accurate product in field of diabetes diagnosis. The drug for preventing and treating diabetes based on hsa-miR-320a in the disclosure provides an effective and safe drug for treating diabetes in field of molecular biology, and provides a new choice to treat diabetes for patients and medical staffs.
Above and other purposes and features of the invention will become clear from the description given below in conjunction with drawings.
The disclosure will be further illustrated with the following specific examples. Advantages and characteristics of the disclosure will become clearer with the description; however, these embodiments are only exemplary and do not limit the scope of the disclosure. A person skilled in the art should understand that details and forms of the technical solution of the disclosure may be modified or replaced without deviating from the conception and scope of the disclosure, but such modifications and replacements fall within the protection scope of the disclosure.
Source of Biological Material
C57 control mice and db/db mice were purchased from Nanjing Model Animal Center (Nanjing, China). 293T cells were from China Center for Type Culture Collection in Wuhan University (Wuhan, China). Enzyme, plasmid, cells used in any of the following experiments and reagents, kit, consumable materials for routine use in various molecular biology experiments are commercially available.
The 1st group of examples: The biomarker for diagnosing diabetes of the invention
This group of examples provides a biomarker for the diagnosing and/or early warning diabetes.
All embodiments in this group have following common features: the biomarker for the diagnosing and/or early warning diabetes comprises sequence fragment containing hsa-miR-320a; the hsa-miR-320a is shown as SEQ ID NO: 1.
In specific embodiments, the biomarker comprises: the hsa-miR-320a.
In a more specific embodiment, the biomarker is the hsa-miR-320a.
The 2nd group of examples: A kit for diagnosing/early warning/risk assessing diabetes of this invention
This group of examples provides a kit for diagnosing and/or early warning diabetes. All examples in this group have following common features: the kit for diagnosing and/or early warning diabetes comprises reagent for quantitative detection of the biomarker of any of the 1st group of examples.
In further examples, the kit comprises reagent for quantitative detection of hsa-miR-320a.
In specific examples, the reagent for quantitative detection of hsa-miR-320a comprises a specific primer pairs for hsa-miR-320a.
In more specific examples, the specific primer pairs are commercially-available MIRQ0000510-1-1.
In preferred examples, the regents for quantitative detection of hsa-miR-320a also comprises reverse transcription reagents; and/or reverse transcription PCR reagents;
In some examples, the quantitative detection refers to fluorescent quantitative PCR detection;
In other preferred examples, the kit comprises miR-320a RT-primers, miR-320a real-time PCR forward primers, miR-320areal-time PCR reverse primers, SYBR Green I, TS reaction enzyme, TS reaction buffer and DEPC ddH2O.
The 3rd group of examples: Use of biomarker of this invention.
This group of examples provides use of the biomarkers described in any of the 1st group of examples in preparing reagents for diagnosing diabetes.
The 4th group of examples: a drug for preventing and treating diabetes of this invention.
This group of examples provides a drug for preventing and treating diabetes. All examples in this group have following common features: an active pharmaceutical ingredient of the drug is taking hsa-miR-320a as drug target, and efficacy of preventing and treating diabetes is achieved by binding, and/or capturing, and/or degrading hsa-miR-320a, and/or down-regulating expression of hsa-miR-320a; The hsa-miR-320a is shown as SEQ ID NO: 1.
In some examples, the active pharmaceutical ingredient of the drug comprises: substance that can degrade hsa-miR-320a and/or down-regulate expression of hsa-miR-320a; preferably, the active pharmaceutical ingredient of the drug is a substance that can down-regulate expression of the hsa-miR-320a.
In some other examples, the active pharmaceutical ingredient of the drug comprises: sequence fragment anti-hsa-miR-320a that is antisense complementary to hsa-miR-320a;
In preferred examples, the antisense complementary refers to that length of the anti-hsa-miR-320a reverse complementary to full-length or partial sequence of the hsa-miR-320a is a sequence fragment of 15-25 bases.
In other preferred examples, the active pharmaceutical ingredient of the drug is a recombinant plasmid expressing the sequence fragment anti-hsa-miR-320a that is antisense complementary to hsa-miR-320a.
In some specific examples, the active pharmaceutical ingredient of the drug is a recombinant adeno-associated virus plasmid pAAV-D(+)-anti-hsa-miR-320a, by which expressed sequence fragment anti-hsa-miR-320a is antisense complementary to hsa-miR-320a;
In some more specific examples, the pAAV-D(+)-anti-miR-320a is constructed by inserting fragment amplified through primer pairs with sequences shown as SEQ ID NO: 4 and SEQ ID NO: 5 into an adenovirus expression vector pAAV-D(+).
In further examples, the drug also comprises pharmaceutically acceptable excipients and/or reagents for buffering, culturing and/or amplifying the recombinant adeno-associated virus plasmid pAAV-D(+)-anti-miR-320a.
The 5th group of examples: a method screening drug for preventing and treating diabetes of this invention
This group of examples provides a method screening drug for preventing and treating diabetes. All embodiments in this group have the following common features: detecting whether candidate substance can bind, capture and degrade hsa-miR-320a and/or down regulate expression;
In preferred examples, substance that can reduce expression level of hsa-mir-320a is screened.
The 6th group of examples: a method for preparing a drug for preventing and treating diabetes of this invention. This group of examples provides a method for preparing a drug for preventing and treating diabetes. All examples in this group have the following common features: the method comprises: taking substance that degrade hsa-miR-320a or down-regulate expression of hsa-miR-320a; sequence fragment anti-hsa-miR-320a antisense complementary to hsa-miR-320a;
In further examples, the method also comprises: primer pairs expressing sequence fragment anti-hsa-miR-320a antisense complementary to hsa-miR-320a is inserted into expression vector to prepare recombinant plasmid stably expressing sequence fragment anti-hsa-miR-320a antisense complementary to hsa-miR-320a.
In specific examples, primer pairs which can express the sequence fragment of anti-hsa-miR-320a antisense complementary to hsa-miR-320a are shown as SEQ ID NO: 4 and SEQ ID NO: 5; the expression vector is adeno-associated virus expression vector pAAV-D(+).
miRNA detection in peripheral blood of diabetic patients.
1. Peripheral blood was collected from 200 diabetic patients and 200 healthy controls. The samples were centrifuged at 3500 rpm for 6 min at room temperature, and the upper plasma was collected and stored at −80° C. 1 mL TRIZOL LS (Invitrogen, USA) was added into 0.25 ml peripheral blood plasma. RNA was extracted using RNasey Mini Kit.
The quality of RNA was detected by Nanodrop® ND-1000.
2. Expression of hsa-miR-320a was detected by real-time PCR through using miRNA detection kit from Guangzhou Ribo Company.
miRNA reverse transcription:
RT Primer Mix:
miRNA RT Primer 1 μL
U6 RT Primer 1 μL
RNase free H2O 78 μL
Reverse transcription reaction system:
RNA template 2 μg
RT Primer Mix 4 μL
RNase free H2O up to 19 μL
Above systems were mixed, centrifuged instantaneously, incubated at 70° C. for 10 min, ice incubated for 2 min; then the following reagents were added:
2×TS reaction buffer 25 μL
TS enzyme 2.5 μL
RNase free H2O 3.5 μL
Reverse transcription reaction procedure:
42° C. for 60 min, 70° C. for 10 min. Standby at 4° C. after shutdown, and the product was stored at −20° C.
miRNAs real-time PCR:
Reaction system: 2×SYBR Green Mix 9 μL
RT product 2 μL
miRNA Forward Primer 2 μL (purchased from Guangzhou Ribo Biotechnology Company Limited)
miRNA Reverse Primer 2 μL (purchased from Guangzhou Ribo Biotechnology Company Limited)
RNase-free H2O 5 μL
reaction procedure:
95° C. 30 sec—(95° C. 10 sec—60° C. 20 sec—70° C. 1 sec)×40 cycles—Melting Curve.
The results showed that expression level of hsa-miR-320a in peripheral blood of diabetic patients was increased (
Sequence of hsa-miR-320a: aaaagcuggguugagagggcga (SEQ ID NO: 1).
Preparing kit to assess diabetes risk.
The kit comprises the following main components: a set of specific reverse transcription primers and real-time PCR primer pairs used for amplifying miR-320a; a set of specific reverse transcription primers and real-time PCR primer pairs used to amplify control RNA (U6) and related reagents. Components and contents are as follows (100 times) and stored at −20° C.:
The above reagents are provided by various companies and have been commercialized. Specific detection methods and related reaction parameters refer to Example 1.
Validation of accuracy of kit for early warning/diagnosing diabetes:
Currently, fasting blood glucose detection and OGTT test are commonly used to diagnose diabetes. Blood samples were collected from 100 patients who had been previously diagnosed with diabetes by above method. The biomarker provided by any of the 1st group of examples and the kit for early warning/diagnosing diabetes provided by the 2nd group of examples of the disclosure are used for molecular detection. The diagnostic criteria for test are: The expression of miR-320a was higher than?? (currently no large-scale population data) is diagnosed as diabetes. The final result shows that there are ??, of which expression level of miR-320a in blood samples of diabetic patients is higher than?. Accuracy of the kit for early warning/diagnosing diabetes is about ?%. (there is no large-scale population data at present).
Currently, fasting blood glucose detection and OGTT test are commonly used to diagnose diabetes. Blood samples were collected from 100 patients who had been previously diagnosed with diabetes by above method. The biomarker provided by any of the 1st group of examples and the kit for early warning/diagnosing diabetes provided by the 2nd group of examples of the disclosure are used for molecular detection. The diagnostic criteria for test are: The expression of miR-320a was higher than that of 50 nmol/L is diagnosed as diabetes. The final result shows that there are 83 patients of which expression level of miR-320a in blood samples of diabetic patients is higher than 50 nmol/L. Accuracy of the kit for early warning/diagnosing diabetes is about 83%.
Construction of recombinant adeno-associated virus
1. Synthesis of inserting sequence
Two reverse complementary strands of hsa-miR-320a and reverse complementary anti-hsa-miR-320a were designed and synthesized, respectively, based on the sequence of hsa-miR-320a (
Primer pairs expressing hsa-miR-320a:
2. Experiments carried out according to the system and temperature in manual Nuclease-Free Water 36 μL
Annealing Buffer for DNA Oligos (5×) 10 μL
DNA oligo A (50 M) 2 μL
DNA oligo B (50 M) 2 μL
90° C. for 3 min, 37° C. for 1 hr, stored at 4° C.
3. Enzyme digestion reaction
Eukaryotic expression vector pAAV-D (+) was digested by BamH I and Not I at 37° C. for 2 hr, digestion reaction system was as follows:
10×K Buffer 1 μL
BSA 1 μL
BamHI 1 μL
Not I 1 μL
pAAV-D(+) 2 μL
ddH2O 14 μL
4. Agarose Gel electrophoresis recovery
Double digestion products were separated by 1% Agarose Gel electrophoresis, and then recovered by TaKaRa Agarose Gel DNA Purification Kit Ver. 2.0. Detailed procedure is as follows:
5. Plasmid ligation
10× T4 DNA ligase buffer 2.5 μL
DNA 0.3 pmol
Vector 0.03 pmol
T4 DNA ligase 1 μL
ddH2O up to 25 μL
Select monoclonal colonies, add them to 3 mL amp+LB liquid medium, and shake at 37° C. 280 rpm overnight. The plasmid was extracted using EasyPure Plasmid MiniPrep Kit purchased from Beijing TransGen Biotechnology Company Limited. The specific steps were as follows:
The constructed plasmids were identified by double enzyme digestion and sequencing, and the eukaryotic expression plasmids pAAV-D(+)-miR-320a and pAAV-D(+)-anti-miR-320a were obtained. Their structures are shown in
Prepare 1 L sterile conical flask, add 300 ml sterile LB medium, and add ampicillin solution to the final concentration of 100 μg/ml. Add 50 μL of the required plasmid (pxx2, pxx8 or pxx9; phelper; pAAV-D(+), pAAV-D(+)-miR-320a or pAAV-D(+)-anti-miR-320a), 280 rpm, 37° C. overnight culture. Plasmids were extracted according to manual of E.Z.N.A.® Endo-Free Plasmid Maxi Kit purchased from OMEGA company. The specific steps were as follows:
293T cells (human embryonic renal epithelial cells) grow to 90%. 1-2 hours before calcium and phosphorus transfection, change 12-15 ml of fresh medium (including serum) for each Petri dish, first add calcium chloride (CaCl2)) into 50 ml centrifuge tube, and then add plasmid to form Ca-DNA mixture, fully mix well, and slowly drop 2×HEBS BUFFER into Ca-DNA mixture to form Ca-DNA-P mixture, Shake the centrifuge tube while adding 2×HEBS to fully mix to form calcium and phosphorus particles. After 8-12 hours, change 18-20 ml serum-free medium. After 72 hours, suck and discard the medium, wash it with PBS for 3 times, add 1 ml Tris+NaCl (pH 8.5) to each Petri dish, curet the cells with a curette, collect them in a clean centrifuge tube and freeze at −80° C.
Take out the cells frozen at −80° C., thaw and dissolve at 37° C., freeze and thaw repeatedly for 4 times, centrifuge at 8000 g for 15 min, put the supernatant into a clean centrifuge tube, and discard the cell precipitation.
Fully mix anhydrous ethanol precooled at −20° C. with rAAV in the volume ratio of 3:1. After being placed in the refrigerator at −20° C. for 2 hours, centrifuge at 4° C. by 13000 rpm for 15 minutes, and discard the supernatant; After ethanol volatilization, add corresponding volume of Tris+NaCl (pH 8.5) to dissolve the precipitation. Filter with millipore filter (0.22 m).
Sample treatment: rAAV virus solution 40 μL
Protease K (20 mg/ml) 5 μL
55° C., reaction 1 hr;
Phenol: chloroform: isoamyl alcohol 45 μL
4° C., 12000 g, centrifugation for 5 min to recover the aqueous phase;
Chloroform 45 μL
4° C., centrifuged at 12000 g for 5 min to recover the aqueous phase.
Real-time PCR:
Primer 1 (10 m) 0.4 μL
Primer 2 (10 m) 0.4 μL
SYBR Green I Mix 10 μL
ddH2O 8.2 μL
Template 1 μL
12. Virus transfection efficiency
After the purified virus was transfected into 293T cells for 48 hours, the proportion of transfected cells was observed by fluorescence microscope, and the transfection efficiency was more than 90% (
A recombinant adeno-associated virus of rAAV9 type expressing hsa-miR-320a/hsa-anti-miR-320a was used as an example to test its therapeutic effect on diabetes and complications.
1. Detection of blood glucose in db/db mice
12 weeks old C57 control and db/db diabetic mice were used to inject rAAV-miR-320a and rAAV-anti-miR-320a through caudal vein injection respectively. Titer of virus was 1×1011 PFU. The fasting blood glucose of db/db mice was detected by taking caudal vein as sample to be tested through test paper at the end of the experiment (12 weeks later). The results showed that the blood glucose of db/db diabetic mice was significantly higher than that of C57 control mice. rAAV-miR-320a treatment significantly increased blood glucose, while rAAV-anti-miR-320a treatment significantly reduced blood glucose (
2. Cardiac function detection of db/db mice
The cardiac function of db/db mice was measured by cardiac ultrasound at the end of the experiment. The methods were as follows:
The instrument used is an ultrasonic instrument equipped with a 30 MHz high-frequency probe. After the mice were anesthetized with isoflurane, the mice were placed on their back on detection platform, and two-dimensional images of the left ventricle were collected along the horizontal short axis and long axis of left ventricular papillary muscle near sternum of mice. At the same time, M-mode ultrasound images of more than 5 consecutive cardiac cycles were obtained respectively under guidance of two-dimensional images. According to the collected images, software was used to analyze results, and cardiac hemodynamic indexes detected by cardiac ultrasound were obtained. After analysis by relevant software, the following indexes were calculated: Heart Rate (HR); Left Ventricular Internal Dimension, diastole, LVIDd; Left Ventricular Internal Dimension, systole, LVIDs, Left Ventricular Posterior Wall, diastole, LVPWd; Left Ventricular Posterior Wall, systole, LVPWs; Interventricular septal thickness; diastole; IVSd; Interventricular septal thickness, systole, IVSs; Ejection Fraction, EF and Fractional Shortening, FS, and etc. The results showed that compared with C57 control mice, the cardiac systolic function of db/db mice was significantly impaired. rAAV-anti-miR-320a treatment could significantly improve the impaired cardiac function of db/db mice, while rAAV-miR-320a treatment could significantly aggravate the cardiac function of damaged db/db mice (
Animal clinical treatment verification on drug preventing and treating diabetes of the invention
Hundreds of diabetic mice were treated with drug preventing and treating diabetes of this invention. Symptoms of each diabetic mouse before treatment include high blood sugar and diabetic complications, for example, impaired cardiac contractility.
Treatment of diabetes was specifically as follows: the drug preventing and treating diabetes provided by any of the 4th group of examples, and/or, drug preventing and treating diabetes screened by the method provided by any of the 5th group of examples, and/or, drug preventing and treating diabetes prepared by the method provided by any of the 6th group of examples were injected into db/db mice once through caudal vein injection at their age of 12 weeks. Virus titer was 1.0×1011 PFU/mouse, and blood glucose and cardiac contractility of each mouse were detected after 12 weeks. It was found that blood glucose and heart systolic function of all diabetic mice were significantly improved after the above treatment (comparison data charts before and after treatment in each mouse were similar to results shown in
| Number | Date | Country | Kind |
|---|---|---|---|
| 201910500477.9 | Jun 2019 | CN | national |
| 201910500630.8 | Jun 2019 | CN | national |
This application is a National Stage Appl. filed under 35 USC 371 of International Patent Application No. PCT/CN2020/090794 with an international filing date of May 18, 2020, designating the United States, now pending, and further claims foreign priority benefits to Chinese Patent Application No. 201910500477.9 filed Jun. 11, 2019, and to Chinese Patent Application No. 201910500630.8 filed Jun. 11, 2019. Inquiries from the public to applicants or assignees concerning this document or the related applications should be directed to: Matthias Scholl P. C., Attn.: Dr. Matthias Scholl Esq., 245 First Street, 18th Floor, and Cambridge, MA 02142.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2020/090794 | 5/18/2020 | WO |
