Protease dependent signalling at the glomerular filtration barrier

肾小球滤过屏障的蛋白酶依赖性信号传导

• 批准号: 281777554
• 负责人: Professor Dr. Berend Isermann
• 金额: --
• 依托单位: Institut für Laboratoriumsmedizin, Klinische Chemie und Molekulare Diagnostik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/281777554?language=en
• 关键词: Protease; dependent; signalling; glomerular; filtration

Diabetic nephropathy (dNP) is gaining pandemic dimensions, putting an enormous burden on affected individuals, health care providers, and insurances. Established therapies, such as blood glucose and blood pressure control delay, but do not avert dNP. In recent years we established an important function of coagulation proteases in regulating glomerular function. In particular, we demonstrated that the serine protease activated protein C (aPC) protects against dNP. This finding has been confirmed by others and clinical studies support such a role of aPC. However, how coagulation protease dependent signalling is regulated locally at the glomerular filtration barrier remains largely enigmatic. Of note, not only receptors for coagulation factors (e.g. protease activated receptors, PARs), but also their regulators, such as thrombomodulin (TM) and tissue factor (TF), and even the proteases themselves (e.g. protein C ,PC), are locally expressed by glomerular cells such as podocytes and endothelial cells. Yet, it remains unknown whether and how locally expressed coagulation factors and regulators contribute to signalling via coagulation proteases. Furthermore, it is not known whether and how endothelial cells and podocytes interact via coagulation proteases. In preliminary work we identified that podocyte specific expression of TM protects against dNP - at least in part independent of PC-activation. Furthermore, we detected an interaction between aPC and alphavbeta3-integrin, which is relevant for podocyte signalling. Likewise, TF modulates glomerular function in dNP. Potential mechanism through which TM and TF may coordinately modulate glomerular function will be evaluated within the current proposal. We wish to determine whether TM provides a functional signaling switch between PAR-1 and integrin dependent signalling and whether TM modulates signalling either by functionally interacting with TF or with intracellular proteins via its cytoplasmic domain. Specifically, we wish to 1) characterize the expression and activity of locally expressed coagulation regulators, 2) evaluate whether TM provides a functional switch between PAR-1 and PAR-3 - avb3 signalling, 3) identify the role of TMs cytoplasmic domain for glomerular cell function and dNP, 4) characterize the functional relevance of TM-dependent complement regulation for TF-activity, 5) delineate the mechanism through which TF modulates glomerular cell function, 6) characterize TM- and TF-mediated receptorsome formation, including the interaction with integrins, 7) analyze the relevance of isomerase switches for protease dependent signalling in podocytes. These comprehensive studies will provide novel insight into coagulation protease dependent signalling in glomerular disease. We expect that these findings will provide new impetus for translational efforts and will have implications for studies addressing coagulation protease signalling in other tissues.

糖尿病性肾病（DNP）正在获得大流行维度，给受影响的个人，医疗保健提供者和保险带来巨大负担。已建立的疗法，例如血糖和血压控制延迟，但不避免DNP。近年来，我们确定了凝结蛋白酶在调节肾小球功能中的重要功能。特别是，我们证明了丝氨酸蛋白酶活化的蛋白C（APC）可预防DNP。其他人已经证实了这一发现，临床研究支持APC的作用。但是，如何在肾小球滤过屏障的局部调节凝结蛋白酶的信号传导在很大程度上仍然是神秘的。值得注意的是，不仅是用于凝血因子的受体（例如蛋白酶活化受体，PARS），还包括其调节剂，例如血小板蛋白（TM）和组织因子（TF），甚至是蛋白酶本身（例如蛋白质C，PC）由肾小球细胞（例如足细胞和内皮细胞）局部表达。然而，尚不清楚是否以及如何通过凝结蛋白酶来局部表达的凝结因子和调节剂有助于信号传导。此外，尚不清楚内皮细胞和足细胞如何通过凝结蛋白酶相互作用。在初步工作中，我们确定了TM的足细胞特异性表达可预防DNP - 至少部分独立于PC激活。此外，我们检测到APC和Alphavbeta3-整合素之间的相互作用，这与Podocyte信号传导有关。同样，TF在DNP中调节肾小球函数。 TM和TF可以协调调节肾小球功能的潜在机制将在当前建议中评估。我们希望确定TM是否在PAR-1和整合素依赖性信号之间提供功能信号转换，以及TM是否通过与TF功能相互作用或通过其细胞质域通过功能相互作用来调节信号传导。具体而言，我们希望1）表征局部表达的凝血调节剂的表达和活性，2）评估TM是否在PAR-1和PAR-3-3-AVB3信号之间提供功能切换细胞功能和DNP，4）表征TM依赖性补体调节TF活性的功能相关性，5）描述TF调节肾小球细胞功能的机制，6）表征TM-和TF介导的受体形成，包括相互作用，包括相互作用使用整联蛋白，7）分析异构酶开关对于蛋白酶依赖性信号的相关性。这些全面的研究将为肾小球疾病中依赖性蛋白酶信号传导提供新的见解。我们预计这些发现将为转化工作提供新的动力，并将对解决其他组织中凝血蛋白酶信号的研究产生影响。