ClC-3氯通道作为甘油三酯代谢调控新靶点的机制研究

Plasma triglyceride levels are closely associated with various cardiovascular diseases and metabolic diseases, thus exploring the target for regulating plasma triglyceride metabolism is of great importance in the development of new drugs. Our preliminary results show that ClC-3 deficiency can attenuate the rise of plasma triglyceride levels as well as the binding and uptake of oxidized low density lipoprotein (oxLDL), which is the ligand of peroxisome proliferator-activated receptor γ/α (PPARγ/α). As well known, the nuclear receptor PPARγ/α is a pivotal factor regulating the metabolism of triglycerides. Thus we put forth the hypothesis that ClC-3 may play a key role in triglyceride metabolism by regulating PPARγ/α expression and activity. To test this hypothesis, we will establish hyperlipidemia model using ClC-3 knockout and wild-type mice to clarify the effect of ClC-3 on triglyceride metabolism; at the cellular level, in-vitro assay methods will be established to evaluate transactivation and binding activity of ligands on PPARγ/α based on reporter gene, and we will observe the effects of cytoplasmic Cl- concentration on PPARγ/α levels and activities; we will apply PPARγ/α inhibitors and siRNA to illuminate the role of PPARγ/α through which ClC-3 puts its effects on triglyceride metabolism. This study will evaluate ClC-3 chloride channel as a novel pharmacologic target of combating hypertriglyceridemia, and provide novel insights into the metabolism of triglyceride and the new drug development.

血浆甘油三酯水平与多种心血管疾病和代谢疾病密切相关，针对甘油三酯代谢机制寻找有效的调控靶点具有重要的理论意义和应用价值。申请人前期研究发现，ClC-3氯通道能够影响血浆甘油三酯水平，且能影响细胞对PPARγ/α配体的摄取。由于核受体PPARγ/α是调控甘油三酯代谢的重要因子，我们推测ClC-3氯通道可能通过调控PPARγ/α表达和活性影响甘油三酯代谢。因此，本课题拟建立ClC-3野生型和敲除型小鼠高脂血症模型，比较ClC-3缺失对甘油三酯代谢的影响；在细胞水平建立基于报告基因的PPARγ/α转录激活活性和结合活性体外评价方法，考察胞内氯离子浓度对PPARγ/α活性的调控作用；结合PPARγ/α抑制剂、基因沉默等技术，阐明ClC-3通过PPARγ/α途径影响甘油三酯代谢的机理，从而系统研究ClC-3氯通道调控甘油三酯代谢的作用机制，为寻找治疗高甘油三酯血症的新药靶点提供理论依据和新思路。

越来越多的临床研究表明，血浆高甘油三酯水平是多种心血管疾病和代谢疾病的危险因素，因此针对甘油三酯代谢过程寻找有效的调控靶点具有重要的理论意义和临床价值。本课题建立了ClC-3野生型和敲除型小鼠高脂血症模型，在整体动物模型上发现，ClC-3缺失抑制了高脂模型动物血浆甘油三酯水平的上升；在细胞水平通过使用氯通道阻断剂等验证了ClC-3氯通道对胞内甘油三酯蓄积的影响；结合实时荧光定量PCR、蛋白免疫印记、siRNA基因沉默等技术，在分子水平探索氯通道阻断对甘油三酯代谢相关分子如ApoA5、ApoC3等的影响，阐明ClC-3氯通道影响甘油三酯代谢的机理，为寻找治疗高甘油三酯血症的新药靶点提供理论依据和新思路。