ABSTRACT
AIM:To investigate the effects of high plasma triglyceride (TG) caused by apolipoprotein C Ⅲ( ApoC Ⅲ) transgene on the occurrence and development of abdominal aortic aneurysm ( AAA) .METHODS:The animal models of hypercholesterolemia and hypercholesterolemia combined with hypertriglyceridemia were established by feeding high-fat diet to LDLR-/-and ApoC Ⅲ+LDLR-/-mice, respectively.AAA was induced in these mice by pancreatic elastase. By evaluating the incidence of AAA, relative maximal abdominal aortic diameter, disruption of the elastic lamellar structure and expression of matrix metalloproteinases ( MMPs) in the aorta walls of the AAA, the occurrence and development of AAA were compared in LDLR-/-and ApoC Ⅲ+LDLR-/-mice fed with either chow diet or high-fat diet.In addition, an in vitro TNF-α-induced aneurysmal microenvironment model on vascular smooth muscle cells ( VSMC) was used to study the impact of triglyceride-rich lipoproteins ( TRLs) from mice with normal or high contents of ApoCⅢon elastin protein expres-sion.RESULTS:Feeding the high-fat diet aggravated the severity of AAA in the LDLR-/-mice.ApoC Ⅲ+LDLR-/-mice fed with high-fat diet had less severe AAA than LDLR-/-mice fed with high-fat diet.TRLs inhibited degradation of VSMC elas-tin protein induced by TNF-α, and in vitro TRLs from the mice with high content of ApoC Ⅲ, compared to those with nor-mal content of ApoC Ⅲ, had better inhibitory effect on the degradation of elastin.CONCLUSION:High plasma TG caused by ApoC Ⅲtransgene alleviates AAA of the LDLR-/-mice induced by elastase and high-fat diet.The effect is probably attrib-uted to the hypertriglyceridemia caused by ApoC Ⅲtransgene.