The Establishment Of Atherosclerosis Models Of Apoe And Ldlr Gene Knockout Rats And Their Systemic Comparison Of Phenotypes

Atherosclerosis(AS)is one of the most prevalent cardiovascular diseases.It is closely related to hyperlipemia,coronary heart disease,myocardial infarction,stroke and other cardiovascular and cerebrovascular diseases.In addition,it is the pathological and physiological basis as well as the pre-symptom of many cardiovascular diseases.Apoe and Ldlr knockout mice have been widely used as animal models of atherosclerosis,but still the pathological characterization of atherosclerosis in mice are quite different from human beings.Such as its locations of onset that are not fully consistent between the two spices.Moreover,the mouse models mimic only the early stages of human atherosclerosis.Without high fat and high cholesterol diet,it's difficult for mice to develop into the stages of vascular stenosisor the formation of the plaques.Besides,the proof on plaque rupture and thrombosis which are important events in humans.All these defects driving scientists to develop a betteranimal model,rats are potential candidates.So far,the gene knockout rats obtained through TALEN technology has been only reported in one article about Apoe gene,for the first time we established Ldlr knockout and Apoe-Ldlr double knockout rat models.Single knockout,double knockout of Apoe and Ldlr gene in rats were established via CRISPR/cas9 system.Rats was divided into two groups depending on their diet:Normal Diet and Western Diet.Physical characteristics,AS characteristics were systematically and comprehensively evaluated.Characteristics of metabolic disease and tissue pathology staining were also performed in the meantime.To this end,these phenotypes were characterized and compared within different genders,different gene types(WT,Apoe KO,Ldlr KO and Double KO)at different time points(4w,8w,14w,24w,48w).We found that knockout of Apoe and Ldlr gene in rats have no obvious influence on physique,and glycometabolism,but led to increased size of versical fat cells.Ldlr-KO,Apoe-KO and DKO rats developed severely dyslipiedemia.Atherosclerosis plaques with various sizes have been found in the carotid bifurcation,aortic arch,thoracic aorta and abdominal aorta,and they are mainly distributed in the entrance of arterioles and small vessels,independent of the gender of rats.However,fatty liver was more severe in females than in males,and Western Diet induction can aggravate fatty liver and atherosclerosis.At the mRNA level,the expression of inflammatory related cytokines such as ICAM-1,C-reactive protein(CRP)and TLR4,as well as lipid metabolism related factors such as LOX-1,CD36,were all increased in liver and aortic arch,in different extents.The enhancement of these cytokines is one of characteristics of atherosclerosis.Our data suggest that Ldlr KO,Apoe KO and DKO rats can be used as novel models for researches of dyslipidemia diseases.DKO and Apoe KO rats can also act as models for atherosclerosis and fatty liver,in considering of their physiological and pathological advantages over mice.