脂肪组织PTP1B表达对局部RAS的调控作用及机制研究

项目名称： 脂肪组织PTP1B表达对局部RAS的调控作用及机制研究

项目编号： No.81000352

项目类型： 青年科学基金项目

立项/批准年度： 2011

项目学科： 轻工业、手工业

项目作者： 顾萍

作者单位： 中国人民解放军南京军区南京总医院

项目金额： 10万元

中文摘要： 背景：本研究以PTP1B为靶点，研究脂肪组织PTP1B表达对局部RAS的调控作用及机制。方法：构建PTP1B重组腺病毒及PTP1B靶向RNAi腺病毒，转染3T3-L1前脂肪细胞，诱导分化获取成熟脂肪细胞。检测：1）脂肪细胞RAS各组分的表达；2）细胞信号通路IRS-1、Akt 和p38MAPK的表达及磷酸化水平；3）TNF-α12289;PPARγ21644;C/EBPα30340;表达。结果：1） PTP1B过表达组脂肪细胞ANT、ACE及AngⅡ#30340;mRNA及蛋白表达增高，而PTP1B抑制表达组ANT、ACEmRNA及蛋白表达下降；2）PTP1B过表达组IRS-1及Akt磷酸化水平下降，p38MAPK磷酸化水平增加，而PTP1B抑制表达组IRS-1及Akt磷酸化水平增加，p38MAPK磷酸化水平下降；3）PTP1B组过表达组TNF-αNA表达增加，PPARγ12289;C/EBPα34507;白表达下降， 而PTP1B抑制表达组TNF-αNA表达下降，而PPARγ12289;C/EBPα34507;白表达增加。结论：PTP1B对脂肪组织局部RAS具有调控作用，其机制可能通过信号通路引起脂肪分化转录因子和因子分泌异常，从而发挥调控RAS的作用。

中文关键词： 蛋白酪氨酸磷酸酶1B； 脂肪分化；信号通路；细胞因子； 肾素-血管紧张素系统

英文摘要： background: Adiposopathy（sick fat）plays a role in the pathogenesis of metabolic diseases which has the potential to scientifically define adipose tissue anatomic and physiologic abnormalities.The local renin angiotensin system(RAS) in the adipos tissue has also been implicated in the pathogenesis of metabolic syndrom.There are many evidences that excessive activation of RAS is associated with adipocyte differentiation and function abnormality. PTP1B is considered a negative regulator of insulin signaling by dephosphorylating the phosphotyrosine residues of the insulin receptor kinase activation segment. Some studies have shown that the function of PTP1B is associated with adipocyte differentiation and function abnormally. Methods Recombinant adenoviruses containing PTP1B (Ad-PTP1B) and siPTP1B（Ad-siPTP1B）sequences were constructed. 3T3-L1 adipocytes were transfected and then assigned to Ad-PTP1B group, Ad-siPTP1B group, Ad-siControl group, and mock control group. Real-time reverse transcription-PCR and Western blot were used to evaluate the expression level of PTP1B, ANT, ACE and AngⅡThe insulin signaling proteins IRS-1, phospho-IRS-1, Akt, phospho-Akt, p38MAPK and phospho-p38MAPK were also measured with Western blotting. And western blot of PPARγd C/EBPαd real-time reverse transcription-PCR of TNF-αre also done. Results：Compared with 3T3-L1 adipocytes treated with Ad-siControl, ad-PTP1B treatment resulted in increase in PTP1B, ANT, ACE and AngⅡRNA levels and protein.Conversely, ad-siPTP1B treatment resulted in decrease in PTP1B, ANT and ACE mRNA levels and protein. And significant decrease and increase of both phosphorylation level of IRS-1 and Akt were found in ad-PTP1B group and ad-siPTP1B respectively when compared with ad-control group. The phosphorylation level of p38MAPK has been increased in ad-PTP1B group and decreased in ad-siPTP1B group. Furthermore, The protein of PPARγd C/EBPαere decreased and TNF-αNA levels were increased in ad-PTP1B group ,but the protein of PPARγd C/EBPαere increased and TNF-αNA levels were decreased in ad-siPTP1B group. Conclution: PTP1B is an important regulator of activation of RAS in adipos tissue.

英文关键词： PTP1B；RAS； adipocyte differentiation； adipocytokines