胰岛素抵抗（IR）是多囊卵巢综合征（PCOS）主要发病机制，前期研究显示LNK可通过抑制前脂肪细胞增殖和胰岛素信号通路参与IR形成。容积调控氯通道蛋白（ClC-3）表达增加可促进前脂肪细胞凋亡，ClC3 -/-2型糖尿病模型中IR和血糖明显改善，提示CLC-3可通过调控脂肪功能和胰岛素受体后机制参与IR发生发展；预实验更提示LNK可在体外与CLC-3结合。由此提出科研假设：LNK可通过与ClC-3相互作用，调控前脂肪细胞增殖和/或凋亡和胰岛素信号通路，参与PCOS中胰岛素抵抗形成。本项目应用LNK cDNA和CLC-3 cDNA/siRNA共转染等分子生物学方法，在细胞、LNK-/- PCOS小鼠和PCOS患者水平，探讨LNK通过与ClC-3相互作用调控胰岛素信号通路和脂肪组织功能的机制，以揭示PCOS胰岛素抵抗发生的新分子网络，为LNK或ClC-3或可成胰岛素抵抗新干预靶点提供科学依据。

Insulin resistance is the one of the main pathogenesis of polycystic ovary syndrome (PCOS). Enlarged adipocytes are taken as an independent predictor for T2DM, which is mainly due to reduced differentiation ability of preadipocytes or the enhanced apoptosis of preadipocytes. Our preliminary data have shown that LNK could inhibit the proliferation of preadipocytes and insulin signaling pathway. LNK polymorphism is also found to be highly associated with insulin resistance in PCOS women. Besides, in our previous studies, volume regulated chloride channel protein is important mediator contributing to cellular volume regulation, proliferation and apoptosis and thereby accounting for many pathological processes in response to volume stress, such as hpertension, stroke and atherosclerosis. Our recent preliminary data showed that ClC-3 could promote apoptosis in preadipocyte; and the insulin resistance, lipid disorders and inflammatory status improved significantly in the ClC-3 KO mice subjected to type 2 diabetes mellitus (T2DM). CLC-3 may be involved in the pathogenesis of insulin resistance via the mechanism of post receptor. These preliminary data suggested that both LNK and ClC-3 should be involved in the pathogenesis and development of insulin resistance, through enhancing the apoptosis of preadipocytes and inhibiting the insulin signaling. During these path-physiologic processes, we proposed the hypothesis that Lnk may have interactions with ClC-3, participating in the formation of insulin resistance in PCOS. To confirm the relationship between Lnk and CLC-3，we performed co-IP experiment and found that they could combine together. The objectives of this project are to elucidate the role and the role and molecular mechanisms that LNK regulated the proliferation, differentiation ability, apoptosis, and insulin signalling pathways in adipose tissue through the interaction with ClC-3, by using the molecular biological methods of co-transfection both Lnk cDNA and CLC-3 cDNA/siRNA into cells, and the investigation of Lnk-/- PCOS mice and PCOS patients. The novelty of this proposal is to identify LNK as a novel molecular mechanism by interacting CLC-3 for insulin resistance in PCOS, and will help in the search of new drug target for improving insulin sensitivity in PCOS women.