蛋白酶活化受体2在糖尿病肾病间质炎症中的作用及机制研究

Renal interstitial inflammation is the important pathophysiologic foundation of diabetic nephropathy. Protease-activated receptors 2(PAR2) correlates tightly with inflammation ,diabetes and renal disease. However, the role of PAR2 in diabetic renal inflammation is unknown. So,we made a research and first time found that the expression of PAR2 protein increased significantly under high glucose(HG) condition. At the same time, the increased interleukin-1β(IL-1β) level was detected. These data suggest a pathogenic role of PAR2 in inflammation of diabetic nephropathy. Based on above, we will reasearch the subject deeply to explore the proinflammatory effect of PAR2 in diabetic nephropathy and its mechanism. .First, we will investigate the expression of PAR2 and the inflammation markers such as IL-1β, monocyte chemoattratctant protein-1(MCP-1) under HG condition in vivo and in vitro. And we will observe the effect of PAR2 silencing , PAR2 overexpression and nature/synthetic PAR2 agonist on the inflammation markers. So, it is aimed to clarify the potential proinflammatory role of PAR2 in the progression of diabetic nephropathy. .Next, a report recently indicates the relationship between PAR2 and the silent information regulator genes(sirtunes, Sirt) in Human Embryonic Kidney cells (HEK293) via cDNA microarray analyses. At the same time, Many studies have associated Sirt1 with inflammatory conditions and kidney disease.And the function of Sirt1 in the progression of diabetic nephropathy remains unknown. So, we will investigate the role of Sirt1 in the kidney under HG condition. Then we will further clarify the relationship between PAR2 and Sirt1 in the development of inflammation in diabetic nephropathy for better understanding the downstream regulation mechanism of PAR2. .The aim of this study, therefore, is to reveal the partial pathogenetic mechanism of DN and validate a new therapeutic avenue for treating.

肾间质炎症反应过程是糖尿病肾病的重要病理生理基础。蛋白酶活化受体2（PAR2）和炎症、糖尿病、肾脏病变有着密切的联系，但PAR2在糖尿病肾病炎症中的作用未见报道。我们的前期研究发现PAR2在高糖环境下表达明显升高，炎症标志物表达升高，提示其在糖尿病肾病中可能起促炎作用。为此，本项目围绕高糖负荷下PAR2和炎症及后续纤维化之间的关系及机制进行深入研究。首先研究高糖负荷时肾小管上皮细胞PAR2的变化及对炎症的影响，明确PAR2在糖尿病肾脏炎症中的确切作用；然后基于微点阵技术提示PAR2活化和Sirt1之间有一定关系、Sirt1在炎症、肾脏疾病中丰富的作用，且尚未有关Sirt1在糖尿病肾病炎症中的报道，本项目将探究Sirt1在糖尿病肾病炎症中的作用，并明确它与PAR2之间的关系，即PAR2在糖尿病肾脏炎症中发挥作用是否呈Sirt1依赖性。旨在揭示糖尿病肾病发病新机制，为从抗炎角度治疗找到新靶向。

肾间质炎症反应过程是糖尿病肾病的重要病理生理基础。蛋白酶活化受体2（PAR2）和炎症、糖尿病、肾脏病变有着密切的联系，但PAR2在糖尿病肾病中的作用未见报道。本课题在前期工作中首次发现PAR2在高糖环境下表达明显升高，炎症标志物表达升高，提示其在糖尿病肾病炎症发生发展中可能起重要作用。为此，本项目围绕高糖负荷下PAR2和炎症及后续纤维化之间的关系及机制进行深入研究。首先研究糖尿病时肾小管上皮细胞PAR2的变化及对炎症的调控作用，明确PAR2在糖尿病肾脏炎症中的确切作用；然后基于微点阵技术检测到PAR2的活化和Sirt1之间的关系、Sirt1在炎症、肾脏疾病中丰富的作用，研究Sirt1在糖尿病时的变化规律以及它对PAR2活化的影响，明确PAR2在糖尿病肾脏炎症中发挥作用是否呈Sirt1依赖性。旨在揭示糖尿病肾病发病新机制，为从抗炎角度治疗找到新靶向。体外研究结果显示，在高糖负荷下，PAR2和炎症因子及其后续纤维化均显著升高。应用PAR2 siRNA转染/PAR2抑制剂能够显著抑制炎症因子的表达，并改善后续纤维化相关指标。另外，在高糖刺激下，Sirt1表达显著下降。应用Sirt1 过表达质粒/活化剂SRT1720能够显著改善炎症及后续纤维化表达。体内单侧输尿管结扎小鼠模型研究显示，应用PAR2抑制剂及Sirt1过表达质粒均能够显著改善小鼠结扎侧肾脏的肾脏病理病变程度、炎症因子表达及纤维化相关表达。同时，我们还在项目书的原有内容上做了拓展，观察了CTGFsiRNA对单侧输尿管结扎肾脏保护作用中Sirt1是否起到了一定作用。通过上述研究，PAR2及Sirt1可能因为与炎症密切相关而参与了肾间质纤维化的过程，可能成为肾间质炎症及纤维化治疗的新靶点。另外，Sirt1并没有参与CTGFsiRNA对单侧输尿管结扎肾脏的保护作用，为CTGFsiRNA的肾脏保护作用新机制研究提供了一定的提示。