A novel mouse model of diabetes, atherosclerosis and fatty liver disease using an AAV8-PCSK9-D377Y injection and dietary manipulation in db/db mice

Biochem Biophys Res Commun. 2022 Sep 24:622:163-169. doi: 10.1016/j.bbrc.2022.07.031. Epub 2022 Jul 15.

Abstract

Preclinical mouse models of cardiometabolic diseases are crucial to study the pathological mechanisms of cardiometabolic diseases and to explore potential new therapeutic agents. Using double-knockouts in the background of ApoE-/- or Ldlr-/- mice requires an extensive amount of breeding and is costly. A significant breakthrough in atherosclerosis research is the use of AAV8-PCSK9-D377Y (a gain-of-function mutant of PCSK9 which promotes LDLR degradation) injection which can induce hyperlipidemia, increased endothelial stiffness, vascular calcification, aneurysm, and atherosclerotic plaque development in normal C57BL/6J mice. The purpose of this study was to assess the possibility that the injection of AAV8-PCSK9 vectors in db/db mice (a well-established animal model of type 2 diabetes mellitus) produces a novel mouse model of diabetes, atherosclerosis and fatty liver disease to study the pathomechanisms of cardiometabolic disease and its complications. Db/db mice were injected with AAV8-PCSK9-D377Y (AAV8-PCSK9 for simplicity) or AAV8-control and fed with high-cholesterol diets for 8 weeks. Levels of total cholesterol (TC) and triglyceride (TG) were significantly elevated in AAV8-PCSK9-injected mice compared to the controls. AAV8-PCSK9 injection led to increased serum level of PCSK9, serious liver steatosis, hypercholesterolemia and atherosclerotic plaque as determined by aortic arch/roots histopathological staining, with Oil Red O, Masson-trichrome and hematoxylin-eosin staining. RNA sequencing and bioinformatics were used to assess the global gene expression in liver tissues. We conclude that AAV8-PCSK9 injection in db/db mice is a promising and time-efficient approach to induce diabetic atherosclerosis with fatty liver. This mouse model can be a new one to investigate the etiology and therapeutics of atherosclerosis with diabetes and fatty liver beyond the traditional model established in ApoE-/- mice or LDLR-/- mice receiving streptozotocin (STZ) injection.

Keywords: Atherosclerosis; Cardiometabolic diseases; Fatty liver; Hypercholesterolemia; PCSK9.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apolipoproteins E / genetics
  • Atherosclerosis* / genetics
  • Atherosclerosis* / metabolism
  • Atherosclerosis* / therapy
  • Cholesterol
  • Diabetes Mellitus, Type 2* / complications
  • Diabetes Mellitus, Type 2* / genetics
  • Diet
  • Disease Models, Animal
  • Fatty Liver*
  • Hypercholesterolemia*
  • Liver Diseases*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Plaque, Atherosclerotic* / genetics
  • Proprotein Convertase 9 / genetics
  • Proprotein Convertase 9 / metabolism
  • Receptors, LDL / genetics
  • Receptors, LDL / metabolism

Substances

  • Apolipoproteins E
  • Receptors, LDL
  • Cholesterol
  • PCSK9 protein, human
  • Pcsk9 protein, mouse
  • Proprotein Convertase 9