鳜plin2生物信息学分析、组织表达及其在肝脏脂肪蓄积中的作用

BIOINFORMATICS AND EXPRESSION ANALYSIS OF PLIN2 IN CHINESE PERCH(SINIPERCA CHUATSI)AND ITS ROLE IN LIVER FAT ACCUMULATION

为探究鱼类脂滴包被蛋白plin2(Perilipin 2)基因的结构和功能,研究成功地克隆并鉴定出鳜(Siniperca chuatsi)plin2的2个亚型,分别命名为plin2a和plin2b。氨基酸多重比对发现其编码序列与刺鱼(Gasterosteus aculeatus)具有高度的同源性。结构域分析发现鳜plin2a和plin2b具有与哺乳动物相似的N末端PAT结构域和11-mer重复结构域。基因共线性分析发现plin2两个亚型在鳜和刺鱼中高度保守。系统发育分析表明鳜plin2和刺鱼、攀鲈(Anabas testudineus)和半滑舌鳎(Cynoglossus semilaevis)近源。RT-qPCR检测了plin2a与plin2b基因在鳜不同组织中的表达分布情况,结果表明鳜plin2a在肝脏中表达最高,其次是脂肪和脾脏组织;相反,plin2b基因在鳜的肝脏中几乎不表达,主要在肾脏、胃、脂肪和脑组织表达。此外,还探究了鳜肝脏和肝细胞在脂肪蓄积状态下plin2a基因的转录水平变化。实验结果表明在过量添加碳水化合物饲喂(8周)后,鳜肝脏中plin2a基因mRNA水平明显升高,鳜肝脏细胞在0.1 mmol/L棕榈酸钠刺激后显著增加了plin2a的mRNA水平。研究表明,鳜plin2两个亚型可能出现功能分化,并且plin2a作为肝脏脂代谢中的重要调节因子,可能在鳜肝脏脂肪蓄积中发挥更重要的功能。

Perlipin2(plin2)belongs to a family of related proteins named perilipin or PLIN(Perlipin),and is expressed in most tissues.plin2 plays a key role in the formation and stabilization of lipid droplets and fatty liver formation.However,little is known about the function of plin2 in Chinese perch(Siniperca chuatsi).This study identified two subtypes of plin2 gene in Chinese perch(Siniperca chuatsi),named plin2a and plin2b,respectively.Domain analysis found that plin2a and plin2b of Chinese perch included the conserved N-terminal PAT domain and 11-mer repeating domain.plin2 systemic analysis revealed that the genes adjacent to two subtypes of plin2 were strictly conserved in Chinese perch and stickleback.According to the phylogenetic analysis,plin2a and plin2b in Chinese perch had a closer relationship with stickleback,climbing perch and tongue sole.Meanwhile,we tested its mRNA expression of plin2a and plin2b in different tissues using real-time quantitative PCR.Both plin2 genes widely distributed but with some differences.plin2a had the highest level in liver,while plin2b had almost no expression in the liver.plin2b was mainly expressed in kidney,stomach,adipose and brain.To explore the function of plin2 in Chinese perch,we detected plin2a mRNA level in high-carbohydrates diet-fed fish.The result showed that compared with fish fed control diet,high-carbohydrate diet significantly increased the hepatic plin2a level.In addition,we found that plin2a mRNA level was also significantly increased after stimulating with 0.1 mmol/L sodium palmitate in Chinese perch hepatocytes.This study shows that the two subtypes of plin2 genes in Chinese perch may have functional differentiation.plin2a,as an important regulator in liver lipid metabolism,may play an important role in the accumulation of fat in the liver of Chinese perch.