LSDP5调控胰岛素抵抗作用机制的研究

Type 2 diabetes has reached epidemic proportions in the word wide. Nonalcoholic fatty liver disease (NAFLD) is associated with hepatic insulin resistance. The predominant differential expression of genes during the pathologic procedure would contribute to develop new drugs. LSDP5 is located on the surface of intracellular lipid droplets, which is one member of PAT family proteins. It is a potent and promising therapeutic target for liver steatosis and insulin resistance. In the present study, we investigate the differential expression of LSDP5 in high-fat diet induced obese mouse model. In vivo, the expression of LSDP5 is reduced via antisense oligonucleotide (ASO) treatment. In vitro, the expression of LSDP5 is increased or decreased by transfecting of high expression plasmid or LSDP5-siRNA plasmid into HepG2 cell line. We investigate the function of LSDP5 on liver steatosis and insulin resistance. Furthermore, we would underline molecular interactions between LSDP5 and pathways involved in lipid metabolism. We expect to clarify the function of LSDP5 and provide new in sight into the pathogenesis of NAFLD and insulin resistance.

非酒精性脂肪性肝病是导致肝脏胰岛素抵抗的主要原因。深入研究该病理过程中重要的差异表达基因及其作用机制将为新药研发提供理论依据。LSDP5是最新发现的PAT家族蛋白成员，定位于细胞内脂肪滴表面，是防治肝脏脂肪变性及胰岛素抵抗的一个极有前途的干预靶点。本研究拟构建高脂膳食诱导脂肪肝和胰岛素抵抗小鼠动物模型，鉴定LSDP5基因表达谱；在体内实验通过腹腔注射靶向基因反义寡核苷酸特异性抑制肝脏LSDP5表达，在体外实验通过"高表达"和"沉默"真核表达载体上调和下调人肝细胞株LSDP5表达，探讨LSDP5基因对肝脏脂肪变性及胰岛素抵抗的调控作用及分子机制；应用酵母双杂交技术寻找可能与LSDP5有特异性相互作用的蛋白分子，并通过免疫荧光染色、免疫沉降及GST融合蛋白沉降技术，验证蛋白质间的相互作用。期望阐明LSDP5的功能，为非酒精性脂肪性肝病和胰岛素抵抗的发病机制及基因干扰工程研究提供新的有效靶标。

胰岛素抵抗是2型糖尿病发病的始动因素。非酒精性脂肪性肝是导致肝脏胰岛素抵抗的主要原因。深入研究该病理过程中重要的差异表达基因及其作用机制将为新药研发提供理论依据。LSDP5是最新发现的PAT家族蛋白成员，定位于细胞内脂肪滴表面，是防治肝脏脂肪变性及胰岛素抵抗的一个极有前途的干预靶点。本研究构建高脂膳食诱导脂肪肝和胰岛素抵抗小鼠动物模型，发现胰岛素抵抗小鼠肝脏LSDP5基因表达增加；在体外实验通过慢病毒介导的“高表达”和“沉默”真核质粒表达载体上调和下调肝细胞株LSDP5表达，结果提示LSDP5基因增加肝细胞内的脂质蓄积，但能促进葡萄糖的摄取，增加p-AKT和p-GSK的表达，减少糖异生但不增加糖酵解。在体内实验通过尾静脉注射慢病毒介导的“高表达”LSDP5的载体，上调肝脏LSDP5基因表达，进一步验证LSDP5的改善胰岛素抵抗的作用，与细胞实验结果不同的是小鼠肝脏过表达LSDP5增加了糖酵解的相关酶GPI的表达。该研究结果为胰岛素抵抗的防治提供了新的靶点。