Cryopyrin/NLRP3 Signaling in Inflammation and Innate Immunity

NLRP 3炎性小体是激活caspase-1和分泌生物学活性的关键平台。 活性IL-1β和IL-18对细菌毒素、颗粒物质和某些内源性刺激的反应。 此外，NLRP 3的异常激活与几种获得性免疫缺陷的发病机制有关。 炎症性疾病，包括痛风性关节炎、硅肺病、动脉粥样硬化、糖尿病和阿尔茨海默氏病 疾病虽然关于激活神经元的刺激和细胞事件已经取得了很大进展， NLRP 3炎性体，该领域的一个主要空白是鉴定炎性体所需的分子。 NLRP 3激活和响应NLRP 3激活刺激的caspase-1激活机制。的 Nek 7激酶在最后一个资助周期中被确定为NLRP 3所需的关键因子 在体外和体内响应于广泛的刺激激活。Nek 7被证明是在 K+外流激活NLRP 3。然而，K+流出通过Nek 7激活NLRP 3的机制是， 仍然未知。此外，NLRP 3通过衔接子激活caspase-1的分子事件 ASC诱导ASC寡聚化和ASC斑点形成的机制尚不清楚。在这次更新中， 应用，我们提出了三个具体的目的研究，以（i）确定如何K+流出激活NLRP 3 使用生物化学和体内方法通过激酶Nek 7抑制炎性小体;（ii）鉴定 调节Nek 7的磷酸化以介导NLRP 3的活化，和（iii）进一步表征 基于肌动蛋白的马达蛋白在ASC介导的炎性小体激活机制中的作用。 了解NLRP 3是如何被激活的，有望为研究NLRP的作用提供重要的见解。 炎症小体在不同的生物系统，这将有助于开发新的治疗 预防和/或治疗炎性小体相关疾病的方法。

The NLRP3 inflammasome is a critical platform for the activation of caspase-1 and secretion of biologically active IL-1β and IL-18 in response to bacterial toxins, particulate matter and certain endogenous stimuli. Furthermore, aberrant activation of NLRP3 has been linked to the pathogenesis of several acquired inflammatory disorders including gouty arthritis, silicosis, atherosclerosis, diabetes and Alzheimer’s disease. Although much progress has been made about the stimuli and cellular events that activate the NLRP3 inflammasome, a major gap in the field is the identification of molecules that are required for NLRP3 activation and the mechanism of caspase-1 activation in response to NLRP3 activating stimuli. The Nek7 kinase was identified during the last cycle of the grant as a critical factor required for NLRP3 activation in response to a wide array of stimuli in vitro and in vivo. Nek7 was shown to act downstream of K+ efflux to activate NLRP3. However, the mechanism by which K+ efflux activates NLRP3 via Nek7 remains unknown. Furthermore, the molecular events by which NLRP3 activates caspase-1 via the adaptor ASC to induce ASC oligomerization and ASC speck formation are poorly understood. In this renewal application, we propose studies in three specific Aims to (i) determine how K+ efflux activates the NLRP3 inflammasome through the kinase Nek7 using biochemical and in vivo approaches; (ii) identify factors that regulate the phosphorylation of Nek7 to mediate the activation of NLRP3 and (iii) further characterize the role of actin-based motor proteins in the mechanism of ASC-mediated inflammasome activation. Understanding how NLRP3 is activated is expected to provide critical insight into the role of the inflammasomes in different biological systems which will aid the development of new therapeutic approaches to prevent and/or treat inflammasome-associated diseases.