Apolipoprotein E deficiency accelerates atherosclerosis development in miniature pigs

Abstract

Miniature pigs have advantages over rodents in modeling atherosclerosis because their cardiovascular system and physiology are similar to that of humans. Apolipoprotein E (ApoE) deficiency has long been implicated in cardiovascular disease in humans. To establish an improved large animal model of familial hypercholesterolemia and atherosclerosis, the clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein 9 system (CRISPR/Cas9) was used to disrupt the ApoE gene in Bama miniature pigs. Biallelic-modified ApoE pigs with in-frame mutations (ApoEm/m) and frameshift mutations (ApoE−/−) were simultaneously produced. ApoE−/− pigs exhibited moderately increased plasma cholesterol levels when fed with a regular chow diet, but displayed severe hypercholesterolemia and spontaneously developed human-like atherosclerotic lesions in the aorta and coronary arteries after feeding on a high-fat and high-cholesterol (HFHC) diet for 6 months. Thus, these ApoE−/− pigs could be valuable large animal models for providing further insight into translational studies of atherosclerosis.

Hyperlipidaemia and cardioprotection: Animal models for translational studies

“…Unbalanced diets containing high levels of fat and carbohydrates, the so-called Western diets (WD), frequently trigger hypercholesterolaemia. Also, genetic factors such as defects in the apolipoprotein genes or receptors (Fan & Watanabe, 2000) influence susceptibility to diet-induced hypercholesterolaemia (DHC). In humans, hyperlipidaemia includes hypercholesterolaemia and hypertriglyceridaemia and is classified as primary, also named as familial, and secondary.…”

“…Watanabe heritable hyperlipidaemic (WHHL) rabbits bear a defect on the LDLr and as a result, they stand as an animal model of unprovoked hypercholesterolaemia, with increased levels of LDL-c and extended atherosclerotic lesions (Fan & Watanabe, 2000). This animal model resembles the FHC seen in humans (Aliev & Burnstock, 1998).…”

“…A Yucatan minipig model of FHC was constructed by DNA transposition of human D374Y‐proprotein convertase subtilisin/kexin type 9 gain‐of‐function mutation, displaying severe hypercholesterolaemia due to decreased LDLr levels and LDL catabolism inhibition and, accordingly, associated with rapidly progressive atherosclerosis (Al‐Mashhadi et al, 2013). Bama minipigs were modified by CRISPR/Cas9, targeting ApoE and LDLr and generating biallelic knockout pigs that presented moderately elevated TC, LDL‐c and apoB levels, which were significantly increased after hypercholesterolaemic diet (Fang et al, 2018). To our knowledge, this model has not been tested in I/R injury.…”

CRISPR-Cas systems: Overview, innovations and applications in human disease research and gene therapy

“…Compared with mice, their body/organ size, lifespan, anatomy, physiology, metabolic profile and immune characteristics are more similar to those of humans, which makes the pig an ideal model for studying human cardiovascular diseases and xenotransplantation [115] . At present, several genetically modified pig models have been successfully generated, including neurodegenerative diseases, cardiovascular diseases, cancer, immunodeficiency and xenotransplantation model [116] , [117] , [118] , [119] , [120] , [121] , [122] .…”

CRISPR-Cas Systems: Prospects for Use in Medicine

“…The HTT gene knockin has resulted in pigs with Huntington's disease clinical manifestation [62]. Currently successful models of atherosclerosis (pig), retinal dystrophy (rat), glioblastoma (mouse), and deafness (mouse) have already been developed [63][64][65].…”