Somatic Editing of Ldlr With Adeno-Associated Viral-CRISPR Is an Efficient Tool for Atherosclerosis Research

Arterioscler Thromb Vasc Biol. 2018 Sep;38(9):1997-2006. doi: 10.1161/ATVBAHA.118.311221.


Objective- Atherosclerosis studies in Ldlr knockout mice require breeding to homozygosity and congenic status on C57BL6/J background, a process that is both time and resource intensive. We aimed to develop a new method for generating atherosclerosis through somatic deletion of Ldlr in livers of adult mice. Approach and Results- Overexpression of PCSK9 (proprotein convertase subtilisin/kexin type 9) is currently used to study atherosclerosis, which promotes degradation of LDLR (low-density lipoprotein receptor) in the liver. We sought to determine whether CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats-associated 9) could also be used to generate atherosclerosis through genetic disruption of Ldlr in adult mice. We engineered adeno-associated viral (AAV) vectors expressing Staphylococcus aureus Cas9 and a guide RNA targeting the Ldlr gene (AAV-CRISPR). Both male and female mice received either (1) saline, (2) AAV-CRISPR, or (3) AAV-hPCSK9 (human PCSK9)-D374Y. A fourth group of germline Ldlr-KO mice was included for comparison. Mice were placed on a Western diet and followed for 20 weeks to assess plasma lipids, PCSK9 protein levels, atherosclerosis, and editing efficiency. Disruption of Ldlr with AAV-CRISPR was robust, resulting in severe hypercholesterolemia and atherosclerotic lesions in the aorta. AAV-hPCSK9 also produced hypercholesterolemia and atherosclerosis as expected. Notable sexual dimorphism was observed, wherein AAV-CRISPR was superior for Ldlr removal in male mice, while AAV-hPCSK9 was more effective in female mice. Conclusions- This all-in-one AAV-CRISPR vector targeting Ldlr is an effective and versatile tool to model atherosclerosis with a single injection and provides a useful alternative to the use of germline Ldlr-KO mice.

Keywords: CRISPR-Cas systems; atherosclerosis; gene editing; hypercholesterolemia; lipoproteins.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenoviridae
  • Animals
  • Atherosclerosis / blood
  • Atherosclerosis / genetics*
  • CRISPR-Associated Protein 9 / genetics
  • Clustered Regularly Interspaced Short Palindromic Repeats*
  • Disease Models, Animal*
  • Female
  • Gene Editing
  • Gene Expression
  • Genetic Vectors*
  • Hypercholesterolemia / blood
  • Hypercholesterolemia / genetics
  • Liver / metabolism
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Proprotein Convertase 9 / blood
  • Proprotein Convertase 9 / genetics
  • Receptors, LDL / blood
  • Receptors, LDL / genetics*


  • Receptors, LDL
  • CRISPR-Associated Protein 9
  • Cas9 endonuclease Streptococcus pyogenes
  • PCSK9 protein, human
  • Proprotein Convertase 9