Novel mechanisms of kidney inflammation and fibrosis

项目摘要 慢性肾脏病（CKD）是一种公共卫生问题，困扰着3700多万美国人。 目前这种进行性疾病的治疗选择是有限的;因此，新的治疗策略 是迫切需要的。CKD的共同特征是肾脏炎症和纤维化。炎症通常会引发 纤维化是慢性炎症反应的最终结果。肾脏炎症的特征是 巨噬细胞活化和促炎分子产生。然而，分子机制 潜在的巨噬细胞活化尚未完全了解。因此，这项建议的长远目标 是了解巨噬细胞激活的分子机制，以便有效的策略， 用于治疗CKD。 我们已经确定PU.1是在肾脏炎症过程中调节肾脏炎症的关键因子。 CKD的发展。具体地说，我们已经证明，PU.1是诱导在肾脏中的实验性 1对于巨噬细胞活化是必需的， 炎症分子产生和CKD的发展。基因缺失或药理学抑制 PU.1在体外防止巨噬细胞活化和巨噬细胞中的炎性分子产生，和 PU.1的药理学抑制抑制了巨噬细胞活化、炎性分子产生， 肾纤维化的发展与梗阻性损伤。此外，PU.1的促炎作用 似乎是由NOD样受体家族含pyrin结构域3（NLRP 3）炎性体介导的 通路在本申请中，我们提出检查和表征PU.1-NLRP 3途径在以下中的作用： 巨噬细胞活化和极化以及促炎和促纤维化分子的产生， 了解炎症和肾纤维化发展的分子机制。我们的中央 假设PU.1促进巨噬细胞中的NLRP 3表达和炎性小体活化，导致 促炎和促纤维化分子的表达和肾纤维化的发展。为了验证这个假设， 我们将追求以下具体目标。具体目的1是确定PU.1在巨噬细胞中的作用， 体外和体内的活化和极化。具体目标2是剖析分子机制， PU.1促进巨噬细胞活化和极化。具体目标3是探索 用于治疗CKD的选择性PU.1抑制剂。 我们计划利用分子、遗传和药理学方法来研究PU的作用。 NLRP 3通路在巨噬细胞活化和极化以及肾纤维化发展中的作用结果 这些研究将为肾脏炎症的分子机制提供新的见解， 开发治疗CKD的新治疗策略。

PROJECT SUMMARY Chronic kidney disease (CKD) is a public health problem that afflicts more than 37 million Americans. The current therapeutic options for this progressive disorder are limited; therefore, novel therapeutic strategies are urgently needed. Common features of CKD are kidney inflammation and fibrosis. Inflammation often triggers fibrosis, and fibrosis is the end result of chronic inflammatory reactions. Renal inflammation is characterized by macrophage activation and proinflammatory molecule production. However, the molecular mechanisms underlying macrophage activation are not fully understood. Therefore, the long-term objective of this proposal is to understand the molecular mechanisms of macrophage activation so that effective strategies can be developed for the treatment of CKD. We have identified PU.1 as a critical factor in the regulation of kidney inflammation during the development of CKD. Specifically, we have demonstrated that PU.1 is induced in the kidney in experimental models of CKD and in human kidney with CKD and PU.1 is obligatory for macrophage activation and inflammatory molecule production and development of CKD. Genetic deletion or pharmacological inhibition of PU.1 prevents macrophage activation and inflammatory molecule production in macrophages in vitro, and pharmacological inhibition of PU.1 suppresses macrophage activation, inflammatory molecule production, and fibrosis development in the kidney with obstructive injury. Furthermore, the proinflammatory effect of PU.1 appears to be mediated by the NOD-like receptor family pyrin domain–containing 3 (NLRP3) inflammasome pathway. In this application, we propose to examine and characterize the role of PU.1-NLRP3 pathway in macrophage activation and polarization and proinflammatory and profibrotic molecule production to further understand the molecular mechanisms of inflammation and development of kidney fibrosis. Our central hypothesis is that PU.1 promotes NLRP3 expression and inflammasome activation in macrophages leading to proinflammatory and profibrotic molecule expression and development of kidney fibrosis. To test this hypothesis, we will pursue the following Specific Aims. Specific Aim 1 is to determine the role of PU.1 in macrophage activation and polarization in vitro and in vivo. Specific Aim 2 is to dissect the molecular mechanisms by which PU.1 promotes macrophage activation and polarization. Specific Aim 3 is to explore the therapeutic potential of a selective PU.1 inhibitor for the treatment of CKD. We plan to utilize molecular, genetic, and pharmacological approaches to examine the role of PU.1- NLRP3 pathway in macrophage activation and polarization and development of kidney fibrosis. Results from these studies will provide novel insights into the molecular mechanisms of kidney inflammation and could lead to the development of novel therapeutic strategies for the treatment of CKD.