RAAV Mediated Human C5L2Gene Therapy Fat Liver Induced By A High Diet In The Wistar Rats

Background and Aim:Recently studies suggest C5L2is the only functional receptor of acylation-stimulating protein (ASP) and associated with lipid and carbohydrate metabolism. ASP-C5L2pathway increases the activity of diacylglycerol acyltransferase (DGAT), stimulates glucose uptake, inhibits hormone-sensitive lipase activity and stimulates insulin secretion. These actions of ASP-C5L2pathway increase the efficiency of triglyceride synthesis and storage in adipocytes. Nonalcoholic fatty liver disease (NAFLD) is a hepatic manifestation of the metabolic syndrome, and is closely associated with lipids disorders and inflammatory. Accumulating studies suggest overexpression C5L2gene may contribute to relieve liver steatosis induced by a high-fat diet. S323I-C5L2mutation previously identified was demonstrated to be loss of function. We hypothesized the gene C512overexpression may alleviate the hepatic steatosis. However, S323I-C5L2mutation overexpression had no effect on NAFLD.Method:We fed the8weeks age old Wistar rats with a high diet (60%calorie from fat)and induced NAFLD model after feeding the high diet for12weeks. We delivered human C5L2cDNA, S323I-C5L2and GFP(as control) in rAAV. The rAAV-C5L2or rAAV-S323I-C5L2or rAAV-GFP (as control) was injected respectively the Wistar rats. All the Wistar rats were sacrificed8weeks after gene delivery. C5L2expression in liver was assessed by Western blot, and the blood biochemical parameters were measured. The hepatic steatosis was evaluated by HE staining and liver triglyceride content. NF-κB inflammation pathway in liver was evaluated by Western blot. The mRNA level of TNF-α and IL-6in liver were measured by Real-time PCR.Results:(1) After rAAV-mediated C5L2gene delivery, C5L2could stable expressed in vivo.(2) In HFD group, C5L2overexpression could sign ificantly decrease theserum levels of TG, glucose, FFA, reduce liver TG content and relieve the hepatic steatosis.(3) In HFD groups, C5L2overexpression could significantly inhibit NF-κBinflammation pathway, and decrease the mRNA levels of the inflammation mediators including TNF-α, IL-6in liver.(4) S323I-C5L2mutant had no effect above.(5) InLFD groups,C5L2and S323I-C5L2had not effect.