Caspase-1调节近端肾小管上皮细胞焦亡在对比剂所致急性肾损伤中的作用

Iodinated contrast media are widely used for disease diagnosis and treatment, which results in increased incidence of contrast-induced acute kidney injury (CI-AKI) in both ambulatory and hospitalized patients. However, the pathogenesis of CI-AKI is not fully understood. Our previous research demonstrated that the administration of iodinated contrast agent could trigger local innate immune response in the kidney. In addition, we found that exogenous Omnipaque and Visipaque could activate NOD-like receptor protein 3 (NLRP3), a sensor of the innate immune system, in human renal proximal tubular epithelial cells (PTECs). By doing so, iodinated contrast media further leaded to increased secretion of IL-18 by PTECs..Non-canonical effect of NLRP3 inflammasome is recently identified, characterized as activation of caspase-1 and pyroptosis. Pyroptosis is a process of caspase-1-dependent immunogenic programmed cell death, which strongly triggers the immune system as a result of the rapid release of unprocessed intracellular contents into the extracellular space. Our preliminary experiments indicated Omnipaque and Visipaque induced pyroptosis-like morphological changes in PTEC. However, the role of caspase-1 mediated pyroptosis in the pathogenesis of CI-AKI remains to be investigated..The current study proposes to set up in vitro and in vivo CI-AKI models by using human PTECs and single nephrectomy mice to investigate the effect of pyroptosis in the pathogenesis of CI-AKI. We will firstly determine whether iodinated contrast agent could trigger pyroptosis (activation of caspase-1, caspase-5/11, IL-1β, secretion of mature IL-18, cell morphologic changes, kidney tubular injury, etc.) in human PTECs and murine kidney tissue. In addition, the relationship between pyroptosis and kidney function decline will be determined. In the second part, experiments are designed to suppress pyroptosis by silencing NLRP3, caspase-1 gene expression, or pharmacologically inhibiting the activity of caspase-1 and caspase-5/11, or preserving plasma membrane permeability of the cells, and then further investigate whether blocking pyroptosis could reduce the incidence of CI-AKI or ameliorate kidney function deterioration during the progression of CI-AKI..These data will allow us to gain further insight into the mechanism of CI-AKI, which is prerequisite to designing novel therapeutic strategies to preserve the structural and functional properties of the kidney after the administration of iodinated contrast media.

碘对比剂所致急性肾损伤（CI-AKI）为住院患者新发急性肾损伤的第三大病因。本课题组研究发现对比剂可激活近端肾小管上皮细胞中先天免疫反应受体NLRP3并致IL-18释放。新近研究发现NLRP3可活化Caspase-1并在Caspase-5/11辅助下引发细胞焦亡，细胞焦亡为炎症型细胞死亡，其剧烈放大了炎症反应，但在CI-AKI中的作用有待研究。.本课题拟通过碘海醇刺激人近端肾小管上皮细胞或诱发小鼠AKI建立CI-AKI实验模型，探讨对比剂可否激活Caspase-1并引起细胞焦亡，并将细胞焦亡与肾功能变化行相关性分析，评估细胞焦亡在CI-AKI发病和进展中的作用。通过沉默NLRP3、Capsase-1表达，或抑制Caspase-1、Caspase-5/11活性，或使用细胞膜稳定剂，探讨多靶点阻断细胞焦亡可否降低CI-AKI的发病并改善预后。本研究可为CI-AKI病理机制和治疗靶点提供新依据。

碘对比剂所致急性肾损伤（CI-AKI）为住院患者新发急性肾损伤的第三大病因。本课题组研究发现对比剂可激活近端肾小管上皮细胞中先天免疫反应受体NLRP3并致IL-18释放。新近研究发现Caspase-4/5/11和Caspase-1参与细胞焦亡，细胞焦亡为炎症型细胞死亡，其剧烈放大了炎症反应，但在CI-AKI中的作用有待研究。. 本课题拟通过碘海醇刺激肾小管上皮细胞和建立CI-AKI实验模型，探讨对比剂可否激活Caspase-4/5/11和Caspase-1并引起细胞焦亡，并将细胞焦亡与肾功能变化行相关性分析，评估细胞焦亡在CI-AKI发病和进展中的作用。通过沉默NLRP3、Capsase-1、Caspase-11表达，或抑制NLRP3、Caspase-1、Caspase-4/5/11活性，探讨多靶点阻断细胞焦亡可否降低CI-AKI的发病并改善预后。本研究可为CI-AKI病理机制和治疗靶点提供新依据。