猪甘油三酯水解酶和激素敏感脂酶基因表达规律的研究

Expression Rule of TGH Gene in Adipose Tissue and Primary Cultured Adipocytes of Pig

利用半定量RT-PCR法分析比较了甘油三酯水解酶(Triacylglycerol hydrolase,TGH)和激素敏感脂酶(Hormone-sensitive lipase,HSL)基因在不同猪种、不同发育阶段及不同部位脂肪组织中转录表达的差异,探讨其在猪脂肪组织的表达规律。结果显示,脂肪型个体TGHmRNA表达丰度显著低于瘦肉型和杂交型个体,成年猪较初生仔猪低,皮下、腹膜和内脏脂肪组织中TGH表达量依次递增;其变化规律与HSL相同。此外,对分离培养的原代前体脂肪细胞通过诱导分化和油红O染色区分分化状态,分析TGHmRNA表达的时序变化,发现TGH在前脂肪细胞中不转录表达,诱导分化后开始表达,且在诱导分化第4天表达量最高,分化第10天表达量下降,达到峰值的时间较HSL早。结果表明,TGH的表达与个体肥胖程度、年龄、脂肪组织部位以及脂肪细胞分化程度相关,同时,在脂肪细胞分化过程中,TGH表达峰值早于HSL,提示TGH在脂肪细胞发育过程中可能较早承担基础脂解作用。

Triacylglycerol hydrolase （TGH） is an intracellular neutral TG lipase identified in mufine adipocytes. To explore the transcriptional expression rule of TGH gene in porcine adipose tissue, mRNA levels of TGH and HSL genes in variously located adipose tissue from pigs in different types, growth stage were assessed by semiquantitative RT-PCR. The results showed that TGH mRNA level was significantly higher in adipose tissue of lean pigs than those of obese and crossbreed ones, and also higher in piglets at birth than mature pigs. On the other hand, the abundance of TGH mRNA increased in the order as subcutaneous, peritoneal and visceral fat . All these variances of TGH gene expression were in accordance with that of HSL gene. To elucidate the time sequence variety of TGH gene expression during the adipocytes differentiation, preadipocytes isolated from adipose tissue of 1-3 day-old piglets were induced to differentiate and the differentiation state was confirmed by Oil Red O staining. The results of TGH gene expression determination showed that instead of expressing in prea differentiating adipocytes and the level reached its peak at which was earlier than that of HSL mRNA did. These data dipocytes, TGH mRNA expressed in 4 d after differentiation induction, indicated that TGH gene expression was related to the site of adipose tissue, economic type, and age of pig as well as differentiating state of adipocyte, implying that TGH might play a major role in the basic lipolysis of adipose.