Patent Application
20230233713
All patents, patent applications and publications cited herein are hereby incorporated by reference in their entirety. The disclosures of these publications in their entireties are hereby incorporated by reference into this application in order to more fully describe the state of the art as known to those skilled therein as of the date of the invention described and claimed herein.
This patent disclosure contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure as it appears in the U.S. Patent and Trademark Office patent file or records, but otherwise reserves any and all copyright rights.
The invention is directed to a hypertension animal model, and methods of using the same to induce heart failure with preserved ejection fraction (HFpEF) responses.
Heart failure (HF) is a chronic and progressive condition where the heart muscle is unable to pump enough blood to meet the body's requirements for blood and oxygen. HF is the most prevalent form of cardiac disease in the US. There are two types of HF: (1) HF with reduced ejection fraction (HFrEF) where the heart does not contract effectively; and (2) HF with preserved ejection fraction (HFpEF) where the heart contractility is normal but is unable to fill properly with blood during the diastolic (filling) phase.
An aspect of the invention is directed to an animal HFpEF composition. In one embodiment the HFpEF composition comprises a hypertensive agent formulated in a dose of about 5 mg/kg to about 100 mg/kg; and an animal chow [HFpEF Diet] comprising about a 50%-50% (wt/wt) proportion of standard diet and custom diet. In one embodiment, the hypertensive agent comprises a pellet or continuous infusion. In another embodiment, the hypertensive agent comprises 11-deoxycorticosterone acetate (DOCA), N(gamma)-nitro-L-arginine methyl ester (L-NAME), or Angiotensin II (ANG II). In one embodiment, the hypertensive agent comprises a pellet or continuous infusion. In one embodiment, the standard diet comprises about 33% carbohydrate, about 3.9% fat, about 16.1% protein, about 0% cholesterol, about 0.4% salt, about 2.3 kcal/g energy density, or a combination of the standard diet components described herein. In one embodiment, the custom diet comprises about 39.8% carbohydrate, about 40% to about 44.1% fat, about 16.2% protein, about 2% cholesterol, about 0.5% to about 0.7% sodium cholate, about 4.01 kcal/g energy density, or a combination of the custom diet components described herein. In one embodiment, the custom diet further comprises about 4% salt. In one embodiment, the custom diet further comprises carbohydrates that comprise about 17.8% fructose. In some embodiments, DOCA is formulated in a dose of about 25 mg/kg to about 100 mg/kg.
An aspect of the invention is directed to a method for inducing heart failure with preserved ejection fraction (HFpEF) in a laboratory animal. In one embodiment, the method comprises administering the HFpEF composition of any one of the animal HFpEF compositions described herein to a swine laboratory animal. In one embodiment, the hypertensive agent comprises 11-deoxycorticosterone acetate (DOCA), N(gamma)-nitro-L-arginine methyl ester (L-NAME), or Angiotensin II (ANG II). In one embodiment, the hypertensive agent comprises a pellet or continuous infusion. In one embodiment, the animal chow comprises about a 50%-50% (wt/wt) proportion of standard diet and custom diet, wherein the standard diet comprises about 33% carbohydrate, about 3.9% fat, about 16.1% protein, about 0% cholesterol, about 0.4% salt, about 2.3 kcal/g energy density, or a combination of the standard diet components described herein; and the custom diet comprises about 39.8% carbohydrate, about 40% to about 44.1% fat, about 16.2% protein, about 2% cholesterol, about 0.5% to about 0.7% sodium cholate, about 4.01 kcal/g energy density, or a combination of the custom diet components described herein. In embodiments, animal chow comprises an HFpEF diet. In one embodiment, the custom diet further comprises about 4% salt. In one embodiment, the custom diet further comprises carbohydrates that comprise about 17.8% fructose. In one embodiment, DOCA is formulated in a dose of about 25 mg/kg to about 100 mg/kg. In one embodiment, the DOCA pellet is administered subcutaneously or orally. In one embodiment, DOCA, L-NAME, or ANG II is administered subcutaneously, intravenously, transdermal, or orally. In one embodiment, the administering occurs from 30 days to 90 days to induce and maintain high blood pressure. In one embodiment, the blood pressure comprises an arterial systolic blood pressure ≥about 130 mmHg, an arterial diastolic blood pressure ≥about 90 mmHg, a mean arterial blood pressure ≥about 100 mmHg, a left ventricular end-diastolic pressure ≥about 14 mmHg, or a combination of these blood pressure readouts. In one embodiment, the blood pressure comprises an arterial systolic blood pressure ≥about 150 mmHg, an arterial diastolic blood pressure ≥about 110 mmHg, a mean arterial blood pressure ≥about 130 mmHg, a left ventricular end-diastolic pressure ≥about 14 mmHg, or a combination of these blood pressure readouts. In one embodiment, the blood pressure further comprises elevated exercise intolerance, and/or LV diastolic dysfunction (elevated E/e′). In one embodiment, the animal chow is provided daily as a total dry weight of about 900 grams. In one embodiment, the method further comprises providing water ad libitum to the animal. In one embodiment, the water comprises about 40 mg salt per 1 liter. In one embodiment, the animal chow and water are administered for at least 20 weeks. In one embodiment, the animal is a swine laboratory animal. In one embodiment, the swine animal is a Gottingen Minipig®.
An aspect of the invention is directed to a method for inducing chronic hypertension in a laboratory animal. In one embodiment, the method comprises administering the composition of any one of the animal HFpEF compositions described herein to a swine laboratory animal. In one embodiment, the hypertensive agent comprises 11-deoxycorticosterone acetate (DOCA), N(gamma)-nitro-L-arginine methyl ester (L-NAME), or Angiotensin II (ANG II). In one embodiment, the hypertensive agent comprises a pellet or continuous infusion. In one embodiment, the animal chow comprises about a 50%-50% (wt/wt) proportion of standard diet and custom diet, wherein the standard diet comprises about 33% carbohydrate, about 3.9% fat, about 16.1% protein, about 0% cholesterol, about 0.4% salt, about 2.3 kcal/g energy density, or a combination of the standard diet components described herein; and the custom diet comprises about 39.8% carbohydrate, about 40% to about 44.1% fat, about 16.2% protein, about 2% cholesterol, about 0.5% to about 0.7% sodium cholate, about 4.01 kcal/g energy density, or a combination of the custom diet components described herein. In one embodiment, the custom diet further comprises about 4% salt. In one embodiment, the custom diet further comprises carbohydrates that comprise about 17.8% fructose. In one embodiment, DOCA is formulated in a dose of about 25 mg/kg to about 100 mg/kg. In one embodiment, the DOCA pellet is administered subcutaneously or orally. In one embodiment, DOCA, L-NAME, or ANG II is administered subcutaneously, intravenously, transdermal, or orally. In one embodiment, the administering occurs from 30 days to 90 days to induce and maintain high blood pressure. In one embodiment, the blood pressure comprises an arterial systolic blood pressure ≥about 130 mmHg, an arterial diastolic blood pressure ≥about 90 mmHg, a mean arterial blood pressure ≥about 100 mmHg, a left ventricular end-diastolic pressure ≥about 14 mmHg, or a combination of these blood pressure readouts. In one embodiment, the blood pressure comprises an arterial systolic blood pressure ≥about 150 mmHg, an arterial diastolic blood pressure ≥about 110 mmHg, a mean arterial blood pressure ≥about 130 mmHg, a left ventricular end-diastolic pressure ≥about 14 mmHg, or a combination of these blood pressure readouts. In one embodiment, the blood pressure further comprises elevated exercise intolerance, and/or LV diastolic dysfunction (elevated E/e′). In one embodiment, the animal chow is provided daily as a total dry weight of about 900 grams. In one embodiment, the method further comprises providing water ad libitum to the animal. In one embodiment, the water comprises about 40 mg salt per 1 liter. In one embodiment, the animal chow and water are administered for at least 20 weeks. In one embodiment, the animal is a swine laboratory animal. In one embodiment, the swine animal is a Gottingen Minipig®.
An aspect of the invention is directed to a method for inducing atherosclerosis in a laboratory animal. In one embodiment, the method comprises administering the composition of any one of the animal HFpEF compositions described herein to a swine laboratory animal. In one embodiment, the hypertensive agent comprises 11-deoxycorticosterone acetate (DOCA), N(gamma)-nitro-L-arginine methyl ester (L-NAME), or Angiotensin II (ANG II). In one embodiment, the hypertensive agent comprises a pellet or continuous infusion. In one embodiment, the animal chow comprises about a 50%-50% (wt/wt) proportion of standard diet and custom diet, wherein the standard diet comprises about 33% carbohydrate, about 3.9% fat, about 16.1% protein, about 0% cholesterol, about 0.4% salt, about 2.3 kcal/g energy density, or a combination of the standard diet components described herein; and the custom diet comprises about 39.8% carbohydrate, about 40% to about 44.1% fat, about 16.2% protein, about 2% cholesterol, about 0.5% to about 0.7% sodium cholate, about 4.01 kcal/g energy density, or a combination of the custom diet components described herein. In one embodiment, the custom diet further comprises about 4% salt. In one embodiment, the custom diet further comprises carbohydrates that comprise about 17.8% fructose. In one embodiment, DOCA is formulated in a dose of about 25 mg/kg to about 100 mg/kg. In one embodiment, the DOCA pellet is administered subcutaneously or orally. In one embodiment, DOCA, L-NAME, or ANG II is administered subcutaneously, intravenously, transdermal, or orally. In one embodiment, the administering occurs from 30 days to 90 days to induce and maintain high blood pressure. In one embodiment, the blood pressure comprises an arterial systolic blood pressure ≥about 130 mmHg, an arterial diastolic blood pressure ≥about 90 mmHg, a mean arterial blood pressure ≥about 100 mmHg, a left ventricular end-diastolic pressure ≥about 14 mmHg, or a combination of these blood pressure readouts. In one embodiment, the blood pressure comprises an arterial systolic blood pressure ≥about 150 mmHg, an arterial diastolic blood pressure ≥about 110 mmHg, a mean arterial blood pressure ≥about 130 mmHg, a left ventricular end-diastolic pressure ≥about 14 mmHg, or a combination of these blood pressure readouts. In one embodiment, the blood pressure further comprises elevated exercise intolerance, and/or LV diastolic dysfunction (elevated E/e′). In one embodiment, the animal chow is provided daily as a total dry weight of about 900 grams. In one embodiment, the method further comprises providing water ad libitum to the animal. In one embodiment, the water comprises about 40 mg salt per 1 liter. In one embodiment, the animal chow and water are administered for at least 20 weeks. In one embodiment, the animal is a swine laboratory animal. In one embodiment, the swine animal is a Gottingen Minipig®.
An aspect of the invention is directed to a method for inducing vascular injury and endothelial dysfunction in a laboratory animal. In one embodiment, the method comprises administering the composition of any one of the animal HFpEF compositions described herein to a swine laboratory animal. In one embodiment, the hypertensive agent comprises 11-deoxycorticosterone acetate (DOCA), N(gamma)-nitro-L-arginine methyl ester (L-NAME), or Angiotensin II (ANG II). In one embodiment, the hypertensive agent comprises a pellet or continuous infusion. In one embodiment, the animal chow comprises about a 50%-50% (wt/wt) proportion of standard diet and custom diet, wherein the standard diet comprises about 33% carbohydrate, about 3.9% fat, about 16.1% protein, about 0% cholesterol, about 0.4% salt, about 2.3 kcal/g energy density, or a combination of the standard diet components described herein; and the custom diet comprises about 39.8% carbohydrate, about 40% to about 44.1% fat, about 16.2% protein, about 2% cholesterol, about 0.5% to about 0.7% sodium cholate, about 4.01 kcal/g energy density, or a combination of the custom diet components described herein. In one embodiment, the custom diet further comprises about 4% salt. In one embodiment, the custom diet further comprises carbohydrates that comprise about 17.8% fructose. In one embodiment, DOCA is formulated in a dose of about 25 mg/kg to about 100 mg/kg. In one embodiment, the DOCA pellet is administered subcutaneously or orally. In one embodiment, DOCA, L-NAME, or ANG II is administered subcutaneously, intravenously, transdermal, or orally. In one embodiment, the administering occurs from 30 days to 90 days to induce and maintain high blood pressure. In one embodiment, the blood pressure comprises an arterial systolic blood pressure ≥about 130 mmHg, an arterial diastolic blood pressure ≥about 90 mmHg, a mean arterial blood pressure ≥about 100 mmHg, a left ventricular end-diastolic pressure ≥about 14 mmHg, or a combination of these blood pressure readouts. In one embodiment, the blood pressure comprises an arterial systolic blood pressure ≥about 150 mmHg, an arterial diastolic blood pressure ≥about 110 mmHg, a mean arterial blood pressure ≥about 130 mmHg, a left ventricular end-diastolic pressure ≥about 14 mmHg, or a combination of these blood pressure readouts. In one embodiment, the blood pressure further comprises elevated exercise intolerance, and/or LV diastolic dysfunction (elevated E/e′). In one embodiment, the animal chow is provided daily as a total dry weight of about 900 grams. In one embodiment, the method further comprises providing water ad libitum to the animal. In one embodiment, the water comprises about 40 mg salt per 1 liter. In one embodiment, the animal chow and water are administered for at least 20 weeks. In one embodiment, the animal is a swine laboratory animal. In one embodiment, the swine animal is a Gottingen Minipig®.
An aspect of the invention is directed to a method for inducing peripheral vascular disease in a laboratory animal. In one embodiment, the method comprises administering the composition of any one of the animal HFpEF compositions described herein to a swine laboratory animal. In one embodiment, the hypertensive agent comprises 11-deoxycorticosterone acetate (DOCA), N(gamma)-nitro-L-arginine methyl ester (L-NAME), or Angiotensin II (ANG II). In one embodiment, the hypertensive agent comprises a pellet or continuous infusion. In one embodiment, the animal chow comprises about a 50%-50% (wt/wt) proportion of standard diet and custom diet, wherein the standard diet comprises about 33% carbohydrate, about 3.9% fat, about 16.1% protein, about 0% cholesterol, about 0.4% salt, about 2.3 kcal/g energy density, or a combination of the standard diet components described herein; and the custom diet comprises about 39.8% carbohydrate, about 40% to about 44.1% fat, about 16.2% protein, about 2% cholesterol, about 0.5% to about 0.7% sodium cholate, about 4.01 kcal/g energy density, or a combination of the custom diet components described herein. In one embodiment, the custom diet further comprises about 4% salt. In one embodiment, the custom diet further comprises carbohydrates that comprise about 17.8% fructose. In one embodiment, DOCA is formulated in a dose of about 25 mg/kg to about 100 mg/kg. In one embodiment, the DOCA pellet is administered subcutaneously or orally. In one embodiment, DOCA, L-NAME, or ANG II is administered subcutaneously, intravenously, transdermal, or orally. In one embodiment, the administering occurs from 30 days to 90 days to induce and maintain high blood pressure. In one embodiment, the blood pressure comprises an arterial systolic blood pressure ≥about 130 mmHg, an arterial diastolic blood pressure ≥about 90 mmHg, a mean arterial blood pressure ≥about 100 mmHg, a left ventricular end-diastolic pressure ≥about 14 mmHg, or a combination of these blood pressure readouts. In one embodiment, the blood pressure comprises an arterial systolic blood pressure ≥about 150 mmHg, an arterial diastolic blood pressure ≥about 110 mmHg, a mean arterial blood pressure ≥130 mmHg, a left ventricular end-diastolic pressure ≥about 14 mmHg, or a combination of these blood pressure readouts. In one embodiment, the blood pressure further comprises elevated exercise intolerance, and/or LV diastolic dysfunction (elevated E/e′). In one embodiment, the animal chow is provided daily as a total dry weight of about 900 grams. In one embodiment, the method further comprises providing water ad libitum to the animal. In one embodiment, the water comprises about 40 mg salt per 1 liter. In one embodiment, the animal chow and water are administered for at least 20 weeks. In one embodiment, the animal is a swine laboratory animal. In one embodiment, the swine animal is a Gottingen Minipig®.
An aspect of the invention is directed to a method for inducing pulmonary hypertension in a laboratory animal. In one embodiment, the method comprises administering the composition of any one of the animal HFpEF compositions described herein to a swine laboratory animal. In one embodiment, the hypertensive agent comprises 11-deoxycorticosterone acetate (DOCA), N(gamma)-nitro-L-arginine methyl ester (L-NAME), or Angiotensin II (ANG II). In one embodiment, the hypertensive agent comprises a pellet or continuous infusion. In one embodiment, the animal chow comprises about a 50%-50% (wt/wt) proportion of standard diet and custom diet, wherein the standard diet comprises about 33% carbohydrate, about 3.9% fat, about 16.1% protein, about 0% cholesterol, about 0.4% salt, about 2.3 kcal/g energy density, or a combination of the standard diet components described herein; and the custom diet comprises about 39.8% carbohydrate, about 40% to about 44.1% fat, about 16.2% protein, about 2% cholesterol, about 0.5% to about 0.7% sodium cholate, about 4.01 kcal/g energy density, or a combination of the custom diet components described herein. In one embodiment, the custom diet further comprises about 4% salt. In one embodiment, the custom diet further comprises carbohydrates that comprise about 17.8% fructose. In one embodiment, DOCA is formulated in a dose of about 25 mg/kg to about 100 mg/kg. In one embodiment, the DOCA pellet is administered subcutaneously or orally. In one embodiment, DOCA, L-NAME, or ANG II is administered subcutaneously, intravenously, transdermal, or orally. In one embodiment, the administering occurs from 30 days to 90 days to induce and maintain high blood pressure. In one embodiment, the blood pressure comprises an arterial systolic blood pressure ≥about 130 mmHg, an arterial diastolic blood pressure ≥about 90 mmHg, a mean arterial blood pressure ≥about 100 mmHg, a left ventricular end-diastolic pressure ≥about 14 mmHg, or a combination of these blood pressure readouts. In one embodiment, the blood pressure comprises an arterial systolic blood pressure ≥about 150 mmHg, an arterial diastolic blood pressure ≥about 110 mmHg, a mean arterial blood pressure ≥about 130 mmHg, a left ventricular end-diastolic pressure ≥about 14 mmHg, or a combination of these blood pressure readouts. In one embodiment, the blood pressure further comprises elevated exercise intolerance, and/or LV diastolic dysfunction (elevated E/e′). In one embodiment, the animal chow is provided daily as a total dry weight of about 900 grams. In one embodiment, the method further comprises providing water ad libitum to the animal. In one embodiment, the water comprises about 40 mg salt per 1 liter. In one embodiment, the animal chow and water are administered for at least 20 weeks. In one embodiment, the animal is a swine laboratory animal. In one embodiment, the swine animal is a Gottingen Minipig®.
An aspect of the invention is directed to a method for inducing fatty liver (steatohepatitis) in a laboratory animal. In one embodiment, the method comprises administering the composition of any one of the animal HFpEF compositions described herein to a swine laboratory animal. In one embodiment, the hypertensive agent comprises 11-deoxycorticosterone acetate (DOCA), N(gamma)-nitro-L-arginine methyl ester (L-NAME), or Angiotensin II (ANG II). In one embodiment, the hypertensive agent comprises a pellet or continuous infusion. In one embodiment, the animal chow comprises about a 50%-50% (wt/wt) proportion of standard diet and custom diet, wherein the standard diet comprises about 33% carbohydrate, about 3.9% fat, about 16.1% protein, about 0% cholesterol, about 0.4% salt, about 2.3 kcal/g energy density, or a combination of the standard diet components described herein; and the custom diet comprises about 39.8% carbohydrate, about 40% to about 44.1% fat, about 16.2% protein, about 2% cholesterol, about 0.5% to about 0.7% sodium cholate, about 4.01 kcal/g energy density, or a combination of the custom diet components described herein. In one embodiment, the custom diet further comprises about 4% salt. In one embodiment, the custom diet further comprises carbohydrates that comprise about 17.8% fructose. In one embodiment, DOCA is formulated in a dose of about 25 mg/kg to about 100 mg/kg. In one embodiment, the DOCA pellet is administered subcutaneously or orally. In one embodiment, DOCA, L-NAME, or ANG II is administered subcutaneously, intravenously, transdermal, or orally. In one embodiment, the administering occurs from 30 days to 90 days to induce and maintain high blood pressure. In one embodiment, the blood pressure comprises an arterial systolic blood pressure ≥about 130 mmHg, an arterial diastolic blood pressure ≥about 90 mmHg, a mean arterial blood pressure ≥about 100 mmHg, a left ventricular end-diastolic pressure ≥about 14 mmHg, or a combination of these blood pressure readouts. In one embodiment, the blood pressure comprises an arterial systolic blood pressure ≥about 150 mmHg, an arterial diastolic blood pressure ≥110 mmHg, a mean arterial blood pressure ≥about 130 mmHg, a left ventricular end-diastolic pressure ≥about 14 mmHg, or a combination of these blood pressure readouts. In one embodiment, the blood pressure further comprises elevated exercise intolerance, and/or LV diastolic dysfunction (elevated E/e′). In one embodiment, the animal chow is provided daily as a total dry weight of about 900 grams. In one embodiment, the method further comprises providing water ad libitum to the animal. In one embodiment, the water comprises about 40 mg salt per 1 liter. In one embodiment, the animal chow and water are administered for at least 20 weeks. In one embodiment, the animal is a swine laboratory animal. In one embodiment, the swine animal is a Gottingen Minipig®.
An aspect of the invention is directed to a method for inducing chronic kidney disease or renal disease in a laboratory animal. In one embodiment, the method comprises administering the composition of any one of the animal HFpEF compositions described herein to a swine laboratory animal. In one embodiment, the hypertensive agent comprises 11-deoxycorticosterone acetate (DOCA), N(gamma)-nitro-L-arginine methyl ester (L-NAME), or Angiotensin II (ANG II). In one embodiment, the hypertensive agent comprises a pellet or continuous infusion. In one embodiment, the animal chow comprises about a 50%-50% (wt/wt) proportion of standard diet and custom diet, wherein the standard diet comprises about 33% carbohydrate, about 3.9% fat, about 16.1% protein, about 0% cholesterol, about 0.4% salt, about 2.3 kcal/g energy density, or a combination of the standard diet components described herein; and the custom diet comprises about 39.8% carbohydrate, about 40% to about 44.1% fat, about 16.2% protein, about 2% cholesterol, about 0.5% to about 0.7% sodium cholate, about 4.01 kcal/g energy density, or a combination of the custom diet components described herein. In one embodiment, the custom diet further comprises about 4% salt. In one embodiment, the custom diet further comprises carbohydrates that comprise about 17.8% fructose. In one embodiment, DOCA is formulated in a dose of about 25 mg/kg to about 100 mg/kg. In one embodiment, the DOCA pellet is administered subcutaneously or orally. In one embodiment, DOCA, L-NAME, or ANG II is administered subcutaneously, intravenously, transdermal, or orally. In one embodiment, the administering occurs from 30 days to 90 days to induce and maintain high blood pressure. In one embodiment, the blood pressure comprises an arterial systolic blood pressure ≥about 130 mmHg, an arterial diastolic blood pressure ≥about 90 mmHg, a mean arterial blood pressure ≥about 100 mmHg, a left ventricular end-diastolic pressure ≥about 14 mmHg, or a combination of these blood pressure readouts. In one embodiment, the blood pressure comprises an arterial systolic blood pressure ≥about 150 mmHg, an arterial diastolic blood pressure ≥about 110 mmHg, a mean arterial blood pressure ≥about 130 mmHg, a left ventricular end-diastolic pressure ≥about 14 mmHg, or a combination of these blood pressure readouts. In one embodiment, the blood pressure further comprises elevated exercise intolerance, and/or LV diastolic dysfunction (elevated E/e′). In one embodiment, the animal chow is provided daily as a total dry weight of about 900 grams. In one embodiment, the method further comprises providing water ad libitum to the animal. In one embodiment, the water comprises about 40 mg salt per 1 liter. In one embodiment, the animal chow and water are administered for at least 20 weeks. In one embodiment, the animal is a swine laboratory animal. In one embodiment, the swine animal is a Gottingen Minipig®.
An aspect of the invention is directed to a method for inducing obesity in a laboratory animal. In one embodiment, the method comprises administering the composition of any one of the animal HFpEF compositions described herein to a swine laboratory animal. In one embodiment, the hypertensive agent comprises 11-deoxycorticosterone acetate (DOCA), N(gamma)-nitro-L-arginine methyl ester (L-NAME), or Angiotensin II (ANG II). In one embodiment, the hypertensive agent comprises a pellet or continuous infusion. In one embodiment, the animal chow comprises about a 50%-50% (wt/wt) proportion of standard diet and custom diet, wherein the standard diet comprises about 33% carbohydrate, about 3.9% fat, about 16.1% protein, about 0% cholesterol, about 0.4% salt, about 2.3 kcal/g energy density, or a combination of the standard diet components described herein; and the custom diet comprises about 39.8% carbohydrate, about 40% to about 44.1% fat, about 16.2% protein, about 2% cholesterol, about 0.5% to about 0.7% sodium cholate, about 4.01 kcal/g energy density, or a combination of the custom diet components described herein. In one embodiment, the custom diet further comprises about 4% salt. In one embodiment, the custom diet further comprises carbohydrates that comprise about 17.8% fructose. In one embodiment, DOCA is formulated in a dose of about 25 mg/kg to about 100 mg/kg. In one embodiment, the DOCA pellet is administered subcutaneously or orally. In one embodiment, DOCA, L-NAME, or ANG II is administered subcutaneously, intravenously, transdermal, or orally. In one embodiment, the administering occurs from 30 days to 90 days to induce and maintain high blood pressure. In one embodiment, the blood pressure comprises an arterial systolic blood pressure ≥about 130 mmHg, an arterial diastolic blood pressure ≥about 90 mmHg, a mean arterial blood pressure ≥about 100 mmHg, a left ventricular end-diastolic pressure ≥about 14 mmHg, or a combination of these blood pressure readouts. In one embodiment, the blood pressure comprises an arterial systolic blood pressure ≥about 150 mmHg, an arterial diastolic blood pressure ≥about 110 mmHg, a mean arterial blood pressure ≥about 130 mmHg, a left ventricular end-diastolic pressure ≥about 14 mmHg, or a combination of these blood pressure readouts. In one embodiment, the blood pressure further comprises elevated exercise intolerance, and/or LV diastolic dysfunction (elevated E/e′). In one embodiment, the animal chow is provided daily as a total dry weight of about 900 grams. In one embodiment, the method further comprises providing water ad libitum to the animal. In one embodiment, the water comprises about 40 mg salt per 1 liter. In one embodiment, the animal chow and water are administered for at least 20 weeks. In one embodiment, the animal is a swine laboratory animal. In one embodiment, the swine animal is a Gottingen Minipig®.
An aspect of the invention is directed to a method for inducing diabetes in a laboratory animal. In one embodiment, the method comprises administering the composition of any one of the animal HFpEF compositions described herein to a swine laboratory animal. In one embodiment, the hypertensive agent comprises 11-deoxycorticosterone acetate (DOCA), N(gamma)-nitro-L-arginine methyl ester (L-NAME), or Angiotensin II (ANG II). In one embodiment, the hypertensive agent comprises a pellet or continuous infusion. In one embodiment, the animal chow comprises about a 50%-50% (wt/wt) proportion of standard diet and custom diet, wherein the standard diet comprises about 33% carbohydrate, about 3.9% fat, about 16.1% protein, about 0% cholesterol, about 0.4% salt, about 2.3 kcal/g energy density, or a combination of the standard diet components described herein; and the custom diet comprises about 39.8% carbohydrate, about 40% to about 44.1% fat, about 16.2% protein, about 2% cholesterol, about 0.5% to about 0.7% sodium cholate, about 4.01 kcal/g energy density, or a combination of the custom diet components described herein. In one embodiment, the custom diet further comprises about 4% salt. In one embodiment, the custom diet further comprises carbohydrates that comprise about 17.8% fructose. In one embodiment, DOCA is formulated in a dose of about 25 mg/kg to about 100 mg/kg. In one embodiment, the DOCA pellet is administered subcutaneously or orally. In one embodiment, DOCA, L-NAME, or ANG II is administered subcutaneously, intravenously, transdermal, or orally. In one embodiment, the administering occurs from 30 days to 90 days to induce and maintain high blood pressure. In one embodiment, the blood pressure comprises an arterial systolic blood pressure ≥about 130 mmHg, an arterial diastolic blood pressure ≥about 90 mmHg, a mean arterial blood pressure ≥about 100 mmHg, a left ventricular end-diastolic pressure ≥about 14 mmHg, or a combination of these blood pressure readouts. In one embodiment, the blood pressure comprises an arterial systolic blood pressure ≥about 150 mmHg, an arterial diastolic blood pressure ≥about 110 mmHg, a mean arterial blood pressure ≥about 130 mmHg, a left ventricular end-diastolic pressure ≥about 14 mmHg, or a combination of these blood pressure readouts. In one embodiment, the blood pressure further comprises elevated exercise intolerance, and/or LV diastolic dysfunction (elevated E/e′). In one embodiment, the animal chow is provided daily as a total dry weight of about 900 grams. In one embodiment, the method further comprises providing water ad libitum to the animal. In one embodiment, the water comprises about 40 mg salt per 1 liter. In one embodiment, the animal chow and water are administered for at least 20 weeks. In one embodiment, the animal is a swine laboratory animal. In one embodiment, the swine animal is a Gottingen Minipig®.
An aspect of the invention is directed to a method for inducing metabolic syndrome in a laboratory animal. In one embodiment, the method comprises administering the composition of any one of the animal HFpEF compositions described herein to a swine laboratory animal. In one embodiment, the hypertensive agent comprises 11-deoxycorticosterone acetate (DOCA), N(gamma)-nitro-L-arginine methyl ester (L-NAME), or Angiotensin II (ANG II). In one embodiment, the hypertensive agent comprises a pellet or continuous infusion. In one embodiment, the animal chow comprises about a 50%-50% (wt/wt) proportion of standard diet and custom diet, wherein the standard diet comprises about 33% carbohydrate, about 3.9% fat, about 16.1% protein, about 0% cholesterol, about 0.4% salt, about 2.3 kcal/g energy density, or a combination of the standard diet components described herein; and the custom diet comprises about 39.8% carbohydrate, about 40% to about 44.1% fat, 1 about 6.2% protein, about 2% cholesterol, about 0.5% to about 0.7% sodium cholate, about 4.01 kcal/g energy density, or a combination of the custom diet components described herein. In one embodiment, the custom diet further comprises about 4% salt. In one embodiment, the custom diet further comprises carbohydrates that comprise about 17.8% fructose. In one embodiment, DOCA is formulated in a dose of about 25 mg/kg to about 100 mg/kg. In one embodiment, the DOCA pellet is administered subcutaneously or orally. In one embodiment, DOCA, L-NAME, or ANG II is administered subcutaneously, intravenously, transdermal, or orally. In one embodiment, the administering occurs from 30 days to 90 days to induce and maintain high blood pressure. In one embodiment, the blood pressure comprises an arterial systolic blood pressure ≥about 130 mmHg, an arterial diastolic blood pressure ≥about 90 mmHg, a mean arterial blood pressure ≥about 100 mmHg, a left ventricular end-diastolic pressure ≥14 mmHg, or a combination of these blood pressure readouts. In one embodiment, the blood pressure comprises an arterial systolic blood pressure ≥about 150 mmHg, an arterial diastolic blood pressure ≥about 110 mmHg, a mean arterial blood pressure ≥about 130 mmHg, a left ventricular end-diastolic pressure ≥about 14 mmHg, or a combination of these blood pressure readouts. In one embodiment, the blood pressure further comprises elevated exercise intolerance, and/or LV diastolic dysfunction (elevated E/e′). In one embodiment, the animal chow is provided daily as a total dry weight of about 900 grams. In one embodiment, the method further comprises providing water ad libitum to the animal. In one embodiment, the water comprises about 40 mg salt per 1 liter. In one embodiment, the animal chow and water are administered for at least 20 weeks. In one embodiment, the animal is a swine laboratory animal. In one embodiment, the swine animal is a Gottingen Minipig®.
An aspect of the invention is directed to a method of treating a swine to cause it to have heart failure with preserved ejection (HFpEF) whereby the swine can be used as an animal model. In one embodiment, the method comprises administering to a swine an animal HFpEF composition; inducing high blood pressure above an arterial systolic blood pressure of about 150 mm HG in the swine by 30 days; and maintaining high blood pressure above an arterial systolic blood pressure of about 150 mm HG in the swine for at least 30 days. In one embodiment, the HFpEF composition comprises a hypertensive agent formulated in a dose of about 5 mg/kg to about 100 mg/kg, wherein the hypertensive agent comprises 11-deoxycorticosterone acetate (DOCA), N(gamma)-nitro-L-arginine methyl ester (L-NAME), or Angiotensin II (ANG II), and an animal chow comprising a 50%-50% (wt/wt) proportion of standard diet and custom diet, wherein the standard diet comprises about 33% carbohydrate, about 3.9% fat, about 16.1% protein, about 0% cholesterol, about 0.4% salt, about 2.3 kcal/g energy density, or a combination thereof, wherein the custom diet comprises about 39.8% carbohydrate, about 40% to about 44.1% fat, about 16.2% protein, about 2% cholesterol, about 0.5% to about 0.7% sodium cholate, about 4.01 kcal/g energy density, or a combination thereof. In one embodiment, the method further comprises increasing circulating LDL cholesterol levels above 150 mg/DL for 30 days. In one embodiment, DOCA is formulated in a dose of about 25 mg/kg to about 100 mg/kg. In one embodiment, the DOCA pellet is administered subcutaneously or orally. In one embodiment, DOCA, L-NAME, or ANG II is administered subcutaneously, intravenously, transdermal, or orally. In one embodiment, the custom diet further comprises 4% salt. In one embodiment, the custom diet further comprises carbohydrates that comprise 17.8% fructose. In one embodiment, the blood pressure comprises an arterial systolic blood pressure ≥about 130 mmHg, an arterial diastolic blood pressure ≥about 90 mmHg, a mean arterial blood pressure ≥about 100 mmHg, a left ventricular end-diastolic pressure ≥about 14 mmHg, or a combination of these blood pressure readouts. In one embodiment, the blood pressure comprises an arterial systolic blood pressure ≥about 150 mmHg, an arterial diastolic blood pressure ≥about 110 mmHg, a mean arterial blood pressure ≥about 130 mmHg, a left ventricular end-diastolic pressure ≥about 14 mmHg, or a combination of these blood pressure readouts. In one embodiment, the animal chow is provided daily as a total dry weight of about 900 grams. In one embodiment, the method further comprises providing water ad libitum to the animal. In one embodiment, the water comprises about 40 mg salt per 1 liter. In one embodiment, the animal chow and water are administered for at least 20 weeks. In one embodiment, the animal is a swine laboratory animal. In one embodiment, the swine animal is a Gottingen Minipig®.
An aspect of the invention is directed to a heart failure with preserved ejection (HFpEF) animal model. In embodiments, the animal model is prepared according to the methods described herein. In one embodiment, the animal is a swine laboratory animal. In one embodiment, the swine animal is a Gottingen Minipig®.
An aspect of the invention is directed to kits for heart failure with preserved ejection (HFpEF) animal model. In one embodiment, the kit comprises an animal HFpEF composition, a Gottingen Minipig® and can further comprise instructions for use. In one embodiment, the animal HFpEF composition comprises a hypertensive agent formulated in a dose of about 5 mg/kg to about 100 mg/kg, and an animal chow. In one embodiment, the hypertensive agent comprises 11-deoxycorticosterone acetate (DOCA), N(gamma)-nitro-L-arginine methyl ester (L-NAME), or Angiotensin II (ANG II). In one embodiment, the hypertensive agent comprises a pellet comprising DOCA formulated in a dose of about 25 mg/kg to about 100 mg/kg. In one embodiment, the animal chow comprises about a 50%-50% (wt/wt) proportion of standard diet and custom diet, wherein the standard diet comprises about 33% carbohydrate, about 3.9% fat, about 16.1% protein, about 0% cholesterol, about 0.4% salt, about 2.3 kcal/g energy density, or a combination of the standard diet components described herein; and the custom diet comprises about 39.8% carbohydrate, about 40% to about 44.1% fat, about 16.2% protein, about 2% cholesterol, about 0.5% to about 0.7% sodium cholate, about 4.01 kcal/g energy density, or a combination of the custom diet components described herein.
Detailed descriptions of one or more embodiments are provided herein. It is to be understood, however, that the invention can be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the invention in any appropriate manner.
The singular forms “a”, “an” and “the” include plural reference unless the context clearly dictates otherwise. The use of the word “a” or “an” when used in conjunction with the term “comprising” in the claims and/or the specification can mean “one,” but it is also consistent with the meaning of “one or more,” “at least one,” and “one or more than one.”
Wherever any of the phrases “for example,” “such as,” “including” and the like are used herein, the phrase “and without limitation” is understood to follow unless explicitly stated otherwise. Similarly, “an example,” “exemplary” and the like are understood to be non-limiting.
The term “substantially” allows for deviations from the descriptor that do not negatively impact the intended purpose. Descriptive terms are understood to be modified by the term “substantially” even if the word “substantially” is not explicitly recited.
The terms “comprising” and “including” and “having” and “involving” (and similarly “comprises”, “includes,” “has,” and “involves”) and the like are used interchangeably and have the same meaning. Specifically, each of the terms is defined consistent with the common United States patent law definition of “comprising” and is therefore interpreted to be an open term meaning “at least the following,” and is also interpreted not to exclude additional features, limitations, aspects, etc. Thus, for example, “a process involving steps a, b, and c” means that the process includes at least steps a, b and c. Wherever the terms “a” or “an” are used, “one or more” is understood, unless such interpretation is nonsensical in context.
As used herein, the term “about” can refer to approximately, roughly, around, or in the region of. When the term “about” is used in conjunction with a numerical range, it modifies that range by extending the boundaries above and below the numerical values set forth. In general, the term “about” is used herein to modify a numerical value above and below the stated value by a variance of 20 percent up or down (higher or lower).
In embodiments, the at least a portion of the HFpEF compositions described herein can be provided as daily feed ration for laboratory animals. For example, laboratory animals can include, mice, rats, donkeys, swine (pigs), dogs, cats, rabbits, horses, sheep, goats, monkeys, and non-human primates. For example, the laboratory animal is a Gottingen Minipig®. As used herein, the term “standard diet,” “control diet,” or “standard control diet” can refer to a normal, calorically balanced maintenance diet that is not designed to induce hypertension or dyslipidemia. In an embodiment, the standard diet comprises a balanced maintenance diet employed for optimum health of the animal. For example, a standard diet will not result in hypertension, obesity, metabolic syndrome, and/or diabetes mellitus in animals and animal models that do not have a predisposition for any of the foregoing. As used herein, the term “standard diet” can be used interchangeably with the term “control diet” and “standard control diet.” As used herein, the term “custom diet” can refer to a diet that can result in an outcome by the consumer of said diet. In embodiments, a Western Diet in combination with a Standard Diet can refer to an HFpEF diet. In an embodiment, a percentage of Western diet can be added to a percentage of a standard diet to create an animal chow. In certain embodiments, a portion of Western Diet can be combined with a portion of a standard diet to create an animal chow. An animal chow can comprise a portion of Western Diet that is about equal to a portion of the standard diet. modified custom. In embodiments, animal chow comprises about a 50/50 mixture (by weight) of Western Diet and standard control diet. The term “animal chow” and “HFpEF diet” can be used interchangeably. In some embodiments, the term “Western Diet” and the term “custom diet” can be used interchangeably. In embodiments, a Western Diet or custom diet can refer to a diet high in fat, fructose, salt, or a combination thereof. In embodiments, the standard diet comprises about 33% carbohydrate, about 3.9% fat, about 16.1% protein, about 0% cholesterol, about 0.4% salt, about 2.3 kcal/g energy density, or a combination thereof. In embodiments, the Western Diet or custom diet comprises about 39.8% carbohydrate, about 40% to about 44.1% fat, about 16.2% protein, about 2% cholesterol, about 0.5% to about 0.7% sodium cholate, about 4.01 kcal/g energy density, or a combination thereof. In embodiments, the standard diet comprises about 33% carbohydrate, about 3.9% fat, about 16% protein, about 0% cholesterol, about 0.4% salt, about 2.3 kcal/g energy density, or a combination thereof. In embodiments, the custom diet comprises about 39.9% carbohydrate, about 40% to about 44.1% fat, about 16.2% protein, about 2% cholesterol, about 0.5% to about 0.7% sodium cholate, about 4.01 kcal/g energy density, or a combination thereof.
In embodiments, the animal chow herein can comprise a high fat content. The fat included in the animal chow may come from more than one fat source. In some embodiments, the animal chow is in the form of feed particles. In some embodiments, a combination of at least two, at least three, at least four, or at least 5 fats are used. Feed particles may be made by methods known in the art.
As used herein, the term “hypertensive agent” can refer to any compound that when administered to a subject increases blood pressure. In embodiments, the hypertensive agent comprises 11-deoxycorticosterone acetate (DOCA), N(gamma)-nitro-L-arginine methyl ester (L-NAME), or Angiotensin II (ANG II). As used herein, the term “blood pressure” refers to the pressure of the blood within the arteries.
In embodiments, an HFpEF composition comprises animal chow and a hypertensive agent.
In one embodiment, the HFpEF composition comprises a hypertensive agent formulated in a dose of less than 5 mg/kg, about 5 mg/kg, about 10 mg/kg, about 15 mg/kg, about 20 mg/kg, about 25 mg/kg, about 30 mg/kg, about 35 mg/kg, about 40 mg/kg, about 45 mg/kg, about 50 mg/kg, about 55 mg/kg, about 60 mg/kg, about 65 mg/kg, about 70 mg/kg, about 75 mg/kg, about 80 mg/kg, about 85 mg/kg, about 90 mg/kg, about 95 mg/kg, about 100 mg/kg, and greater than 100 mg/kg.
In an embodiment, the animal chow comprises about 10%-90% wt/wt proportion of standard diet and custom diet, about 20%-80% wt/wt proportion of standard diet and custom diet, about 25%-75% wt/wt proportion of standard diet and custom diet, about 30%-70% wt/wt proportion of standard diet and custom diet, about 40%-60% wt/wt proportion of standard diet and custom diet, about 50%-50% wt/wt proportion of standard diet and custom diet, about 55%-45% wt/wt proportion of standard diet and custom diet, about 60%-40% wt/wt proportion of standard diet and custom diet, about 65%-35% wt/wt proportion of standard diet and custom diet, about 70%-30% wt/wt proportion of standard diet and custom diet, about 75%-25% wt/wt proportion of standard diet and custom diet, about 80%-20% wt/wt proportion of standard diet and custom diet, about 85%-15% wt/wt proportion of standard diet and custom diet, about 90%-10% wt/wt proportion of standard diet and custom diet, and about 95%-5% wt/wt proportion of standard diet and custom diet.
In an embodiment, the HFpEF compositions described herein can be used for administration to laboratory animals for the induction of heart failure with preserved ejection fraction (HFpEF) for the purposes of modeling the disease. In embodiments, the HFpEF model described herein recapitulates several comorbidities of HFpEF. In embodiments, comorbidities of HFpEF can comprise hypertension, old age, obesity, hypercholesterolemia, pre-diabetic phenotype, pulmonary and/or systemic arterial hypertension, diabetes mellitus, or a combination of the co-morbidities described herein.
In embodiments, the animal chow (HFpEF diet) described herein may include fat, nutritional components and other additives. For example, nutritional components can include starch, carbohydrates, and protein components. For example, other additives can include amino acids, vitamins, minerals, fatty acids, nutraceuticals, pharmaceuticals, and the like. In embodiments, additives can be added to the nutritional components or fat components of the animal chow. In embodiments, the animal chow can comprise starches such as corn, wheat, barley, oats, sorghum, tapioca, isolated dry or wet milled starch, their milled components or a combination thereof. For example, amino acids can comprise aspartic acid, glutamic acid, alanine, glycine, threonine, proline, serine, leucine, isoleucine, valine, phenylalanine, tyrosine, methionine, cystine, lysine, histidine, arginine, and tryptophan. For example, minerals can comprise calcium, phosphorus, non-phytate phosphorus, sodium, potassium, chloride, magnesium, sulfur, zinc, manganese, chloride, fluorine, cobalt, chromium, copper, iodine, iron, and selenium. For example, vitamins can comprise Vitamin A, Vitamin D3, Vitamin E, Vitamin K, Vitamin B2, Vitamin B12, thiamin, riboflavin, menadione, pantothenic acid, pyridoxine, ascorbic acid, niacin, biotin, carotene, folic acid, and choline chloride. For example, fatty acids can comprise palmitic acid, stearic acid, oleic acid, linoleic acid, arachidonic acid, linolenic acid, and omega-3 fatty acids.
In embodiments, the animal chow described herein comprise protein components. For example, protein sources can comprise soybean meal, amino acids, casein, cottonseed meal, and corn gluten meal, other oil seed meals, animal-by products, plant by-products, and microbial protein. In embodiments, the composition comprises at least one source of fiber.
In embodiments, the animal chow comprises fructose, dehulled soybean meal, wheat middlings, hydrogenated soy oil, casein, ground soybean hulls, ground corn, high fructose corn syrup-55, hydrogenated coconut oil, lard, salt, dicalcium phosphate, glucose, cholesterol, soybean oil, cane molasses, calcium carbonate, sodium cholate, potassium bicarbonate, powdered cellulose, vitamin/mineral premix (trace mineral premix, sodium selenite, pyridoxine hydrochloride, biotin, calcium pantothenate, folic acid, D-Alpha Tocopheryl Acetate, cholecalciferol, zine oxide, Vitamin B-12 supplement, Vitamin A Acetate, riboflavin supplement, sucrose, eat carotene, nicotinic acid, thiamine mononitrate, calcium iodate, copper sulfate, chromium chloride), magnesium oxide, dicalcium phosphate, menadione dimethylpyrimidinol, bisulfate, ethoxyquin.
The following examples are given for the purpose of illustrating various embodiments of the invention and are not meant to limit the present invention in any fashion. One skilled in the art will appreciate readily that the present invention is well adapted to carry out various embodiments of the invention. Changes therein and other uses which are encompassed within the spirit of the invention as defined by the scope of the claims will occur to those skilled in the art.
Examples are provided herein to facilitate a more complete understanding of the invention. The following examples illustrate the exemplary modes of making and practicing the invention. However, the scope of the invention is not limited to specific embodiments disclosed in these Examples, which are for purposes of illustration only, since alternative methods can be utilized to obtain similar results.
Composition and Methods of Developing a Swine Model of Heart Failure with Preserved Ejection Fraction
Composition
1. Gottingen Minipig®
2. DOCA
3. HFpEF Diet
4. Salt
5. Water
Methods
1) The use of the Gottingen minipig (Marshall BioResources, Inc) is used to provide the proper genetic predisposition for development of a swine model of heart failure with preserved ejection fraction (HFpEF).
2) The use of 11-deoxycorticosterone acetate (DOCA) is utilized to provide proper development of this swine model of HFpEF. DOCA is administered in pellet form and is implanted subcutaneously. DOCA pellets are manufactured by Innovative Research of America, Inc. A dose range of ≥25-<100 mg/kg; for a 30-90 day release is utilized to induce and maintain high blood pressure throughout the protocol (arterial systolic blood pressure ≥130 mmHg, arterial diastolic blood pressure ≥90 mmHg and mean arterial blood pressure ≥100 mmHg). The DOCA could be delivered in alternative routes of administration.
The use of a diet composed of a 50/50 (wt/wt) proportion of standard diet and custom diet is necessary to provide proper development of this swine model of HFpEF. A total dry weight of 900 grams of the newly composed 50/50 diet (termed HFpEF diet) is provided to the animals daily. The HFpEF diet is used to induce hypercholesterolemia, pre-diabetic mellitus condition, and to aid in the induction and maintenance of high blood pressure.
The salt component in this instance is supplemented into the custom diet. Alternatively, the salt could be administered through the drinking water.
Access to drinking water ad libitum is necessary to induce and maintain high blood pressure.
The combination of HFpEF diet, DOCA and water is maintained in the Gottingen minipig for 20 weeks (5 months) in order to develop a swine HFpEF model (
Hypercholesterolemia
1. Custom diet (WD)—
Ossabaw High Fat High Fructose
(TestDiet® 5B4L w/ 4% Total Salt—9GZC)
Hypertension (HTN)
1. Deoxycorticosterone acetate (DOCA) pellets
(Innovative Research of America SM-121) (100 mg/kg/day [90-day release])
Implanted (S.C.) behind the left ear
2. Dietary Salt (approximate 4%)
Hypercholesterolemia
1. HFpEF Diet—Mixture (50/50) of Standard Dietz and Custom Diet
Standard Diet—
Mini-Pig Breeder (ENVIGO 8753)
Custom Diet—
Ossabaw High Fat High Fructose
(TestDiet® 5B4L w/ 4% Total Salt—LT479)
Hypertension (HTN)
1. Deoxycorticosterone acetate (DOCA) pellets
(Innovative Research of America SM-121) (50 mg/kg/day [60-day release])
Implanted (S.C.) behind the left ear
2. Dietary Salt (approximate 2.2%)
Background—Increasing prevalence of heart failure with preserved ejection fraction (HFpEF) coupled with a lack of effective therapies represents a significant unmet need in cardiovascular medicine. Likewise, a lack of preclinical animal models which recapitulate the comorbid-laden syndrome has led to the inability to tease out mechanistic insights and test new therapeutic strategies. Herein, we developed a preclinical large animal model integrating multiple co-morbid determinants of HFpEF in a miniswine breed that exhibits sensitivity to obesity, metabolic syndrome and vascular disease with overt clinical signs of heart failure.
Methods and Results—Female Gottingen miniswine were fed a standard diet or Western diet (WD) to induce metabolic syndrome coupled with 11-deoxycorticosterone acetate (DOCA)—salt induced hypertension over a 20-week period. Serial echocardiographic assessment was performed over the 20-weeks. Invasive hemodynamics were measured at baseline and 20-weeks. Gottingen miniswine treated with WD+DOCA demonstrated obesity, hypercholesterolemia, a pre-diabetic phenotype and sustained hypertension at 20-weeks. While LVEF was preserved, comorbidities led to LV concentric hypertrophy and diastolic dysfunction as measured by E/e′ and left atrial remodeling, elevated filling pressures, pulmonary hypertension and venous congestion. Endothelial-dependent vascular dysfunction was present in the HFpEF group along with histopathological abnormalities including cardiac fibrosis, adipose infiltrate, pulmonary remodeling, and extensive renal fibrosis.
Conclusions—The combination of WD and DOCA-salt induced hypertension in the Gottingen miniswine led to the development of a new preclinical large animal model of HFpEF exhibiting multi-organ involvement and a full spectrum of comorbidities associated with human HFpEF.
A lack of preclinical large animal models of HFpEF which recapitulate the comorbid-laden syndrome has led to the inability to tease out mechanistic insights and test therapeutic strategies. Herein, we developed a large animal model integrating multiple co-morbid determinants of HFpEF in a miniswine breed that exhibits sensitivity to obesity, metabolic syndrome and vascular disease with overt clinical signs of heart failure. The combination of WD and DOCA-salt induced hypertension in the Gottingen miniswine led to the development of a new large animal model of HFpEF exhibiting multi-organ involvement and a full spectrum of comorbidities associated with human HFpEF.
CVP Central Venous Pressure
DBP Diastolic Blood Pressure
DOCA 11-Deoxycorticosterone Acetate
EF Ejection Fraction
HFpEF Heart Failure with Preserved Ejection Fraction
IVGTT Intravenous Glucose Tolerance Test
LAFAC Left Atrial Fractional Area of Change
LV Left Ventricle
MAP Mean Arterial Pressure
PASP Pulmonary Systolic Pressure
PCWP Pulmonary Capillary Wedge Pressure
PW Pulse Wave
SBP Systolic Blood Pressure
WD Western Diet
Heart failure with preserved ejection fraction (HFpEF) has emerged as cardiovascular medicine's most complex, comorbidity-laden, heterogenous disease. The increasing prevalence of HFpEF in an obese, diabetic, hypertensive, aging population coupled with lack of effective treatments further complicates this critical public health problem(1). Though complex in its multi-organ pathophysiology, all patients suffering from HFpEF exhibit increased left ventricular filling pressure and reduced exercise tolerance with a preserved left ventricular ejection fraction(2,3). Despite the clear cardiac indices, it is the extra-cardiac comorbidities that are integral in disease progression and actively contribute to the syndrome of HFpEF(4). While there are several shared comorbidities between heart failure with reduced ejection fraction (HFrEF) and HFpEF patients, the higher burden of a subset of comorbidities associated with HFpEF results in a higher risk of mortality(5). Within the growing number of cardiac and noncardiac comorbidities, the most common risk factors/comorbidities associated with HFpEF are age, female gender, hypertensions, renal impairment, diabetes and obesity(5).
The pathophysiological mechanisms involved in disease progression of HFpEF have yet to be clearly defined due to the lack of robust and translationally relevant animal models. The multiple phenotypes in HFpEF has proven difficult to recapitulate in an animal model. Typically, a single organ-single stressor approach is usually favored when developing animal models making the multiple comorbidities associated with HFpEF difficult to mimic in the laboratory(4). One rodent model which has overcome this limitation and has shown to recapitulate several comorbidities through genetic selection is the ZSF-1 obese rat. The ZSF-1 rat model, which crosses the spontaneous hypertensive heart failure rat with a Zucker diabetic fatty rat, provides an overlapping genetic phenotype which predisposes the animals to hypertension and metabolic syndrome, two major prerequisites for the development of HFpEF (6). Several laboratories have demonstrated abnormalities in these animals the parallel human HFpEF (6,7). Various species and models have been used to model concentric LV hypertrophy, a hallmark of HFpEF, though none perfectly resemble the complex myocardial milieu seen with HFpEF. The hypertrophic, fibrotic and impaired relaxation phenotype has been successfully modeled in dogs by repeated coronary microembolization(8) and in aged hypertensive dogs by renal wrapping(9); however, due to societal intolerance for canine experimentation and a growing number of phenotypically-selective breeding and genetically-modified pigs available, swine represent a more suitable large animal for HFpEF model development.
Swine models of HFpEF have been described with varying success using the most prominent amongst the comorbidities: hypertension, obesity and diabetes mellitus generated typically as a single-insult or as a two-hit approach. Models that utilize hypertension as the sole-driver of HFpEF pathophysiology include those that focus the hypertension directly to the myocardium by mechanical manipulations to facilitate pressure overload left ventricular hypertrophy. Devices constricting the aorta with bands(10,11), cuffs(12,13) and stents(14), mitral regurgitation valve chordae rupture(15) and renal artery stenosis combined with ventricular pacing(16) all result in increased myocardial mass, stiffness and fibrosis; however, the absence of multi-organ pathogenic effects significantly limit their clinical applicability. In contrast, pharmacological approaches to induce LV hypertrophy in swine through systemic hypertension by vasopressor(17-19) lack the severity to meaningfully impact cardiac function and fail to demonstrate overt heart failure at rest. Additionally, efforts to incorporate obesity and diabetic comorbidities has been performed through Western diets (WD) high in fat, fructose and salt either alone or in combination with additional stressors in healthy swine(19-22) and strains predisposed to exhibit metabolic syndrome(23,24) and yet these models have failed to faithfully mimic the human HFpEF condition.
Unlike humans, many wild-type animal strains are highly resistant to diabetes, hypertension, atherosclerosis, and fail to exhibit cardiovascular diseases following prolonged exposure to risk factors(25-27). Utilizing animals predisposed to cardiovascular disease provides an optimal background on which exposure to a WD and hypertension will ultimately induce HFpEF. Gottingen miniswine, bred for small size and ease of handling in a laboratory setting, were developed by crossbreeding the Vietnamese, Hormel, and German improved Landrace swine(28). The Gottingen miniswine are described in relation to glucose metabolism and obesity, with propensity to develop various aspects of the metabolic syndrome including obesity, insulin resistance, and glucose intolerance when fed various high fat, WDs(28-30). The Gottingen miniswine also exhibits a propensity for development of dyslipidemia, vascular disease and atherosclerosis(29). Though diabetes and obesity are contributing comorbidities, hypertension is critical in driving the pathophysiological HFpEF phenotype of concentric hypertrophic LV remodeling, myocardial fibrosis and impaired ventricular relaxation.
Using a multi-hit minimally invasive approach, we endeavored to create a clinically relevant miniswine model that combines three common comorbidities (metabolic syndrome, hypertension, female sex) that contribute to the complex pathophysiology of human HFpEF. Superimposing systemic hypertension using deoxycorticosterone acetate (DOCA) onto diet-induced obesity and a pre-diabetic phenotype in female Gottingen miniswine results in a new animal model that exhibits the full spectrum of comorbidities and multi-organ involvement associated with HFpEF disease progression.
Methods
Experimental Design
All animal experiments were performed in accordance with the Guide for the Care and Use of laboratory Animals, the Public Health Service Policy on the Humane Care and Use of Laboratory Animals, and the Animal Welfare Act. Institutional Animal Care and Use Committee (IACUC) approval was obtained from the Louisiana State University Health Sciences Center—New Orleans prior to initiation of these experimental studies.
Fourteen-month old, intact female Gottingen minipigs (17 to 20 kg) were acquired (Marshall BioResources, Rose, N.Y.) and assigned to 2 groups: healthy Control (n=3) and WD+deoxycorticosterone acetate (DOCA)-induced HFpEF (n=8). One HFpEF animal succumbed to sudden death of unknown causes 9 weeks; two HFpEF animals exhibiting severe end-organ damage, lethargy and poor overall health were humanely euthanized at 10 weeks and these animals were not included in the final data analysis. Adjustments to amounts of HFpEF diet and DOCA were implemented with final constituents detailed below and final outcome measures in the HFpEF group assessed in a total of 5 animals.
The Control group were fed a standard diet (8753, Teklad Miniswine Diet, Envigo; 2.3 kcal/g-1; carbohydrate: 33%; protein: 16%; fat: 3.9%: cholesterol: 0% wt/wt; salt, sodium chloride: 0.4%; 900 g/day), whereas the HFpEF group was fed 50/50 (wt/wt) mix of standard diet and custom WD containing high levels of fat, fructose, cholesterol and salt (9GZC TestDiet, St. Louis, Mo.: Ossabaw atherosclerotic diet type 5B4L w/ 4% total salt; 4.01 kcal/g-1; carbohydrate: 39.9% [17.8% high-fructose corn syrup]; protein: 16.2%; fat: 40%; cholesterol: 2%; sodium cholate: 0.7%; 900 g/day). Animals were fed once per day and water was provided. Minipigs in the HFpEF group received a subcutaneous DOCA depot (50 mg/kg, 200 mg pellets, 60-day release, Innovative Research of America, Sarasota, Fla.). Altogether, Gottingen miniswine in the Control group (n=3) and in the HFpEF group (n=5) were on-study for a total of 20 weeks (
Blood Collection
Venous blood samples were obtained from anesthetized animals at baseline and at 4, 8, 12, 16 and 20 weeks, processed for serum, snap frozen and stored at −80° C. Total cholesterol (TC), low density lipoprotein (LDL), and high density lipoprotein (HDL) levels were measured (IDEXX Laboratories, Memphis, Tenn.)
Transthoracic Echocardiography
At baseline, 4, 8, 12, 16 and 20 weeks, transthoracic echocardiography (Vivid E9, M5S transducer, GE Healthcare, Wauwatosa, Wis.) was performed in miniswine under ketamine/xylazine induction anesthesia (15 mg/kg/1.5 mg/kg, IM) and then isoflurane anesthesia (1.5% in 100% oxygen) as maintenance. To ensure accurate and consistent image acquisition, diltiazem (0.25 mg/kg) was administered to reach a target heart rate <90 bpm(31). Left ventricular (LV) volumes and ejection fraction was measured using 2D auto EF. Auto EF utilizes speckle tracing technology and Simpson's method to track the endocardium through systole and diastole(32). LV wall thickness at end-systole and end-diastole were measured from subcostal 2D B-mode images acquired at the level of the mitral valve leaflets as previously described (32). Left atrial (LA) areas and fractional area of change were measured from subcostal 2D B-mode views (33).
Pulse wave (PW) doppler echocardiography, with a maximal corrected angle of 40°, was used to assess transmitral inflow velocities during diastole at the level of the mitral valve orifice. The ratio of peak early (E) and late (A) transmitral velocities was calculated. PW tissue doppler imaging, with a maximal corrected angle of 40°, was used to calculate tissue velocities during early ventricular filling (e′) at the mitral valve medial and lateral annulus. Medial and lateral ratios of early transmitral inflow and tissue velocity (E/e′) were calculated(33). All images were acquired by a single cardiovascular researcher (TES) experienced in miniswine echocardiography. Analysis were performed offline in a blinded fashion (GE EchoPAC Software, Version 202, GE Healthcare, Wauwatosa, Wis.).
Invasive Hemodynamics
Miniswine underwent invasive systemic, left ventricular, and pulmonary hemodynamic measurements at baseline and at 20 weeks. Animals were sedated as above, intubated, ventilated and maintained under methohexital (Brevital, 7.0-8.0 mg/kg/hr, IV) as previously described(32,34,35). Electrocardiogram, heart rate, respiration rate, 02 saturation, arterial blood pressure and body temperature were continuously monitored. Using standard sterile technique, percutaneous femoral artery and vein sheath introducers were placed under ultrasound guidance (Vivid E9, ML6-15 transducer, GE Healthcare, Wauwatosa, Wis.). Systemic arterial blood pressures (SBP, DBP, MAP) were obtained using from femoral artery access and recorded on the TruWave Pressure Transducer® (Edwards Lifescience, Irvine, Calif.). For left ventricular hemodynamics, a solid state single-pressure catheter (Millar Instruments, TX) was advanced through the ascending thoracic aorta via femoral artery access under fluoroscopic guidance (Optima CL232i; GE Healthcare Wauwatosa, Wis.) and subsequently placed in the LV chamber for recording of LV pressures. Steady-state data was recorded (PowerLab 8/35, ADInstruments, Colorado Springs, Colo.) under spontaneous heart rate for a minimum of 10 consecutive beats with the ventilator tidal volume set to zero to eliminate respiratory artifact. Right heart catheterization was performed with a Swan-Ganz catheter (Edwards Lifesciences, Irvine, Calif.) placed in the left branch of the pulmonary artery via femoral vein access. Central venous pressure (CVP), pulmonary artery systolic, diastolic, mean and wedge pressure (PASP, and PCWP, respectively) were recorded (TruWave Pressure Transducer, Edwards Lifescience, Irvine, Calif.). Pressure measurements were performed offline in a blinded fashion (LabChart 8 Software, ADInstruments, Colorado Springs, Colo.).
Central Venous Line Placement and Intravenous Glucose Tolerance Testing
For intravenous glucose tolerance test (IVGTT) serial blood sampling, minipigs were sedated, anesthetized using isoflurane as above and an indwelling catheter (Hickman, C. R. Bard, Inc, Salt Lake City, Utah) surgically placed in the right jugular vein as previously described(34,35). Surgical complications with implantation of one indwelling catheter led to only four HFpEF animals undergoing the IVGTT. Animals were recovered for 3 days prior to IVGTT. At 20 weeks, conscious, overnight fasted miniswine received an intravenous bolus of 50% glucose solution (0.5 g/kg body weight, Animal Health International, Patterson, Colo.) and blood samples (3 ml) collected at −5, 0, 2.5, 5, 10, 20, 30, 40, 50, 60 min. Blood glucose levels were monitored (Contour Blood Glucose Monitoring System, Bayer Healthcare, Mishawaka, Ind.) and plasma insulin values were measured (Insulin ELISA, Mercodia, Winston-Salem, N.C.).
Euthanasia
At 20 weeks, minipigs were sedated, intubated, and anesthetized as above. Heparin (300 U/kg IV) administered and under deep anesthesia, minipigs were euthanized (potassium chloride, KCl, 40 mEq/kg IV, Hospira, Inc, Lake Forest, Ill.) in accordance with the 2013 Edition of the AVMA Guidelines for the Euthanasia of Animals.
Ex Vivo Coronary Vascular Reactivity
Hearts were excised, and the left anterior descending (LAD) and circumflex (LCX) coronary arteries carefully dissected, cut into 3-5 mm rings and mounted onto the tension apparatus within organ bath chambers (Radnoti, Glass Technology, Monrovia, Calif.) with oxygenated Krebs buffer for isometric tension experiments as previously described(32,36). Briefly, LAD and LCX coronary arterial rings were placed under 2 grams of preload tension and allowed to stabilize for 60-90 min. Coronary arterial ring viability was assessed using 50 and 100 mM KCl consecutively. Rings were washed, precontracted with prostaglandin (PGF2a, 30 μM) and endothelial-dependent relaxation concentration curves were generated using bradykinin (1011 to 10−6 M) and substance P (10−12 to 10−8 M). Endothelial-independent relaxation concentration curves were generated using sodium nitroprusside (SNP, 10−9 to 10−5M). Maximal relaxation and half maximal effective concentration (EC50) were calculated.
Circulating Biomarkers of Cardiovascular Disease Risk
To assess oxidative stress in our model we measure 8-isoprostane levels in plasma from baseline, 4, 12 and 20 weeks in all animals using an enzyme-linked immune-assay kit (Cayman Chemical Company, Ann Arbor, Mich.). Endothelin-1 has been well established as a marker of endothelial dysfunction (37). Circulating serum levels of endothelin-1 were measured at baseline, 4, 12 and 20 weeks in all animals using an enzyme-linked immune-assay kit (Enzo Lifescience, Farmingdale, N.Y.).
RNA Isolation and PCR Analysis of Natriuretic Peptides
Real-time PCR (qPCR) mRNA levels of left ventricular expression of natriuretic peptides were assessed as previously describe (32). Briefly, mRNA was isolated from left ventricular tissue and gene expression of atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP).
Fibrosis Staining and Quantification
Heart, lung, liver and kidney specimens were harvested, fixed in 10% neutral buffered formalin, processed for paraffin embedding, sections cut (5 μm), stained with Masson's trichrome and photomicrographs acquired. Left ventricular, pulmonary, hepatic and renal cortical fibrosis was quantified by calculating the percentage of total Masson's trichrome positive tissue (blue) over the total tissue area using image J software. Hepatic lobule area was quantified by identification of the central vein and portal triads along the perimeter with an outline drawn around the perimeter and through the portal triads to acquire hepatic lobule area.
Statistical Analysis
All data are expressed as the mean±standard error of the mean (SEM). Statistical analyses were performed using Prism 6 (GraphPad Software, San Diego, Calif.). Repeated 2-way analysis of variance (ANOVA) was performed for multiple comparisons between two groups over time with a Sidak post-hoc test correction for multiple comparisons. A Student unpaired, 2-tailed, τ test was performed when comparing data from two groups at a single time point. A p-value of <0.05 was considered statistically significant.
Results
Gottingen Minipigs' Enhanced Sensitivity to Multiple Cardiovascular Disease Insults
Based on previous studies using WD-induced obesity in Gottingen minipigs(28,29), Gottingen miniswine were fed full rations of the custom WD containing 2% cholesterol and 4% sodium chloride (9GZC TestDiet, St. Louis, Mo.). Since DOCA-induced hypertension had not been previously performed in Gottingen miniswine, we based our initial DOCA implantation regimen of 100 mg/kg, 90-day release pellets on reported literature using Landrace pigs(20). Following 4 weeks of WD diet and DOCA (100 mg/kg, 90-day), serum cholesterol levels increased 20-fold (data not shown) and Gottingen miniswine (n=3) were returned to standard control diet. Though cholesterol levels were improved when placed on standard diet, it appeared that the high levels of DOCA contributed to the moribund condition of the pigs and consequently, one Gottingen minipig was lost due to sudden death and the other two minipigs were humanely euthanized due to severe end-organ damage. As a result of the early mortalities, animals in the HFpEF group were subsequently fed a modified custom WD (50/50 wt mix with standard control diet [HFpEF diet]) and implanted with DOCA at 50 mg/kg, 200 mg pellets, 60-day release.
Gottingen Minipigs Exhibit Obesity and Hypercholesterolemia
Minipigs fed the HFpEF diet for 20 weeks gained significant (p<0.05) weight starting at 12 weeks compared to control diet fed animals (
Altered Glucose Metabolism and Circulating Insulin Levels in Response to IVGTT
Minipigs underwent intravenous glucose tolerance testing at 20 weeks to determine systemic responsiveness towards a glucose metabolism (
Biomarkers of Cardiovascular Disease Risk
Oxidative stress is a driving force of long-term abnormalities in cardiovascular disease. 8-isoprostane was measure in the plasma in all animals at baseline, 4, 12, and 20 weeks in the study (
DOCA- and Salt-Induced Hypertension
DOCA pellet implantation (50 mg/kg, 60-day release) and increased dietary salt intake in HFpEF miniswine resulted in significant elevations in systemic blood pressures at 20 weeks (
Preserved LV Systolic Function with Progressive Diastolic Dysfunction
Echocardiograms acquired every 4 weeks revealed that systolic LV function was maintained over the 20-week study (
Diastolic function was assessed by measuring mitral valve inflow velocity using pulse wave doppler and tissue doppler echocardiography of the medial and lateral mitral valve annulus (
Increased LV Wall Thickness and Concentric Hypertrophy
Serial echocardiographic assessment of left ventricular structure showed progressive and significant thickening of the LV walls in HFpEF miniswine (
Elevated LV Filling Pressures with Left Atrial Remodeling and Dysfunction
In the HFpEF minipigs, we observed a significant elevation in left ventricular pressures coupled with adverse remodeling and function of the left atria (
Pre- and Post-Capillary Pulmonary Hypertension
Right heart catheterization was performed at baseline and 20 weeks to assess pulmonary pressures (
Impaired Coronary Artery Endothelial Function
In the setting HFpEF, there is profound coronary artery dysfunction manifested by impaired relaxation to endothelial-dependent agonists(1). At 20 weeks, left anterior descending (LAD) and left circumflex (LCX) coronary arteries were isolated from control and HFpEF Gottingen minipig hearts. Ex vivo vasodilatory responses to endothelial-dependent (bradykinin and substance P) and -independent (sodium nitroprusside) agonists are shown (
Multi-Organ Histopathology with Increased LV Myocardial and Renal Fibrosis
In HFpEF minipigs, representative photomicrographs of left ventricular Masson's trichrome stain demonstrate increased myocardial fibrosis associated with interstitial lipid deposition within the mid-myocardium (
In this study, we report a large animal model of HFpEF induced through dietary and chronic mineralocorticoid administration using a minipig breed with known susceptibilities toward obesity and metabolic syndrome, and atherosclerosis. Severe LV diastolic dysfunction was evidenced by significant elevations in end-diastolic pressure, diastolic early filling velocities (E/e′), coupled with profound myocardial hypertrophic and fibrosis during which EF was preserved. We observed significant vascular injury and dysfunction evidenced by pulmonary and systemic hypertension as well as impaired coronary artery endothelial-dependent vasorelaxation responses in vitro. In addition to the cardiac pathology, this HFpEF model encompasses impairments across multiple organ systems including pancreas, liver and kidney as exhibited by significant blunting of glucose and insulin handling, elevated circulating cholesterol levels and increased renal fibrosis. The combination of established methods of DOCA-salt induced hypertension and WD metabolic syndrome have not been previously performed in Gottingen miniswine. Our results describe a unique miniswine translational animal model that exhibits the spectrum of multi-organ pathophysiology characteristic of human HFpEF.
There is universal agreement that the lack of suitable preclinical animals models of HFpEF is among the largest roadblocks to advancing our understanding of HFpEF and developing new therapies to treat HFpEF patients. Most of the previous described HFpEF models consist of cardiac pressure-overload to induce LV concentric hypertrophy and diastolic dysfunction, but these models fail to fully capture the characteristics of human HFpEF and have not proven to be reliable for preclinical evaluation of potentially new therapeutic targets(38). Purported animal models of HFpEF exhibit select features of human condition and do not truly reflect the full spectrum of pathological phenotypes observed in HFpEF patients(39). The Gottingen minipig DOCA-salt and WD model described here is to our knowledge the only large animal model to date that exhibits definite evidence of advanced, severe HFpEF. Clinically, diagnostic confirmation of HFpEF requires either elevated LV filling pressures at rest (LVEDP >16 mmHg) or an elevated mean capillary wedge pressure at rest (PCWP >15 mmHg) in the presence of normal systolic LV function (LVEF >50%)(40-43). As we've demonstrated, the Gottingen DOCA-salt and WD model exhibits elevated LV filling pressures at rest (LVEDP, 17.7±0.3 mmHg) and elevated mean capillary wedge pressure at rest (PCWP, 19.8±0.7 mmHg) in the presence of normal systolic LV function (LVEF, 64.3±1.8%). Furthermore, this model is representative of advanced HFpEF as LV filling pressures were elevated at rest, whereas earlier stage HFpEF, is characterized by LV pressure increases observed only during exercise(22). Several other swine models have established comorbid-laden models attempting to mimic HFpEF (24,44); however, they do not demonstrate the clinical endpoints necessary for classification of HFpEF, specifically the non-invasive diastolic echocardiographic measurement of E/e′ and the invasive hemodynamic measurements of elevated LV end-diastolic pressure or elevated PCWP (42,45).
It is well recognized that diastolic dysfunction by itself is not enough to produce HFpEF and additional cardiac and extracardiac abnormalities involving multiple organs are critical in capturing the heterogenicity of HFpEF pathophysiology. In the present study we utilized a systemic, multi-organ approach by subjecting the whole animal to hypertension and a high fat, high salt WD resulting in a spectrum of pathologies involving a number of organs. Moreover, the diverse spectrum of HFpEF pathologies encompassed in this Gottingen minipig HFpEF model is ideally suited for evaluating the degree to which each of the organ systems is altered and the relative impact of each comorbidity on the overall clinical condition(38).
Until now, absence of an animal model that comprehensively exhibited the heterogenicity of the HFpEF clinical condition forcing the field to compromise and reluctantly accepted animal models that only recapitulated partial HFpEF phenotypes(38). Developing a disease phenotypically characterized by multi-comorbidities and multi-organ dysfunction, is further complicated in that each comorbidity is in itself a stand-alone multifaceted disease with distinct phenotypes driven by a combination of different genetic, dietary and environmental factors. The challenge, similar to that observed among patients with HFpEF, is that with a higher burden of comorbidities comes a higher risk of mortality(5). So too, high mortality rates have been reported in many preclinical HF swine models induced using multiple insults to mimic the multiple comorbidities (21) as had occurred during our initial development of the model. Early in model development, we failed to recognize the unique impact of the Gottingen minipig strain on disease progression. Reliance on previously reported doses and duration of DOCA administration using younger Landrace swine(20,46,47), proved catastrophic causing circulating lipid levels to soar, systemic and LV pressures to skyrocket resulting in rapid end-organ damage and circulatory collapse.
The “too much, too fast” is certainly not the clinical scenario as aging in the setting of long-standing hypertension and metabolic syndrome are critically important contributors to the HFpEF condition. Gottingen miniswine are commonly used as models of obesity, metabolic syndrome and hypercholesterolemia(28-30) manifesting as early as after 2-5 weeks of high-cholesterol/high-fat diet in comparison to most other metabolic syndrome swine models including the Ossabaw strain where features of this disorder require 3-6 months of diet to appear. The applicability of using the Gottingen minipig strain over other swine strains for modeling human HFpEF is further evidenced by its genetic diversity. It has been suggested that similar to human HFpEF, the use of outbred murine colonies could contribute to a better experimental setting because, in contrast, the use of inbred strains represents limited genetic diversity and might not reflect the responses generated in a diverse human population(1,48). Though the Ossabaw strain encompasses descendants of minipigs brought from Spain, their isolation on Ossabaw Island has resulted in a breed that has lived in relative genetic isolation for centuries(49). Gottingen minipig genetic diversity stems from the crossbreeding the Minnesota minipig, the Vietnamese pot-bellied pig, and the German Landrace pig(28). Lastly, and equally important when developing animal models designed to assess therapeutic efficacy of interventions, body size often limits the type of study. The major advantage of rodents is the fact that pharmacological studies require lesser amounts of test agents and rodents are suitable for genetic manipulations to create transgenic models that aid in the elucidation of pathological mechanisms. However, given the current lack of effective treatments for HFpEF coupled with the multifactorial nature of HFpEF pathophysiology, devices and technologies are also being explored thereby necessitating animals large enough as would be deployed in HFpEF patients. The size of the Gottingen minipig makes this strain more suitable for HFpEF studies in that they are the smallest of the swine breeds thereby facilitating pharmacological studies while at the same time large enough for device testing.
In summary, our results demonstrate that the combination of DOCA-salt induced hypertension and a high salt, WD-induced metabolic syndrome in the Gottingen minipig strain exhibit a full spectrum of HFpEF phenotypes. This large animal model of HFpEF represents an important preclinical research tool that will drive future studies to identify key molecular mechanisms and evaluate potential therapeutics for HFpEF. The Gottingen minipig HFpEF model also permits a multidimensional phenotypic readout of therapeutic efficacy (i.e. antihypertensive effects, obesity and metabolic syndrome effects), which can help identify patient subgroups most likely to benefit from a specific intervention.
Clinical Competencies—The increasing prevalence of heart failure with preserved ejection fraction (HFpEF) coupled with a lack of effective therapies represents a unmet need in cardiovascular medicine. The heterogeneity of the syndrome has created a challenging task to pinpoint the underlying mechanism which drive human HFpEF. This is further exacerbated by a lack of preclinical models which effectively recapitulate the clinical scenario. In order to better understand the pathological drivers of HFpEF manifestation and progress, new preclinical models must be developed.
Translational Outlook—The lack of preclinical animal models that encompass the systemic, multi-organ dysfunction and comorbid-laden phenotype observed in patients has led to an inability to tease out mechanistic insights and test new therapeutic strategies. Herein, we have developed a large animal model integrating multiple co-morbid determinants of HFpEF in a miniswine breed that exhibits sensitivity to obesity, metabolic syndrome and vascular disease with overt clinical signs of heart failure. This model will allow for identification of key mechanisms and testing of new therapeutic strategies thereby permitting better clinical translation.
Those skilled in the art will recognize, or be able to ascertain, using no more than routine experimentation, numerous equivalents to the specific substances and procedures described herein. Such equivalents are considered to be within the scope of this invention, and are covered by the following claims.
This application claims priority from U.S. Provisional Application No. 63/044,865, filed on Jun. 26, 2020, and U.S. Provisional Application No. 63/104,678, filed on Oct. 23, 2020, the entire contents of each of which are incorporated herein by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2021/039130 | 6/25/2021 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63044865 | Jun 2020 | US | |
| 63104678 | Oct 2020 | US |
