PDF(Pubmed)
Abstract：
Diabetic cardiomyopathy (DCM) is a chronic disease caused by diabetes mellitus, which is recognized as a worldwide challenging disease. This study aimed to investigate the role and the potential mechanism of knocking down the NACHT-, LRR- and PYD domains-containing protein 3 (NLRP3), an inflammasome associated with onset and progression of various diseases, on high glucose or diabetes -induced cardiac cells pyroptosis and ferroptosis, two regulated non-necrosis cell death modalities discovered recent years. In the present study, both in vivo and in vitro studies were conducted simultaneously. Diabetic rats were induced by 55 mg/kg intraperitoneal injection of streptozotocin (STZ). Following the intraperitoneal injection of MCC950 (10 mg/kg), On the other hand, the DCM model in H9C2 cardiac cells was simulated with 35 mmol/L glucose and a short hairpin RNA vector of NLRP3 were transfected to cells. The results showed that in vivo study, myocardial fibers were loosely arranged and showed inflammatory cell infiltration, mitochondrial cristae were broken and the GSDMD-NT expression was found notably increased in the DM group, while the protein expressions of xCT and GPX4 was significantly decreased, both of which were reversed by MCC950. High glucose reduced the cell viability and ATP level in vitro, accompanied by an increase in LDH release. All of the above indicators were reversed after NLRP3 knockdown compared with the HG treated alone. Moreover, the protein expressions of pyroptosis- and ferroptosis-related fators were significantly decreased or increased, consistent with the results shown by immunofluorescence. Furthermore, the protective effects of NLRP3 knockdown against HG were reversed following the mtROS agonist rotenone (ROT) treatment. In conclusion, inhibition of NLRP3 suppressed DM-induced myocardial injury. Promotion of mitochondrial ROS abolished the protective effect of knockdown NLRP3, and induced the happening of pyroptosis and ferroptosis. These findings may present a novel therapeutic underlying mechanism for clinical diabetes-induced myocardial injury treatment.
摘要：
糖尿病性心肌病(DCM)是由糖尿病引起的慢性疾病,这被认为是一种世界性的具有挑战性的疾病。本研究旨在探讨敲除NACHT的作用和潜在机制。含LRR和PYD结构域的蛋白3（NLRP3），与各种疾病的发生和发展有关的炎症小体，高糖或糖尿病诱导的心肌细胞焦亡和铁凋亡，近年来发现的两种调节非坏死细胞死亡模式。在本研究中,同时进行体内和体外研究。采用55mg/kg腹腔注射链脲佐菌素(STZ)诱导糖尿病大鼠。腹膜内注射MCC950（10mg/kg）后，另一方面,用35mmol/L葡萄糖模拟H9C2心肌细胞的DCM模型，并将NLRP3的短发夹RNA载体转染到细胞中。结果表明,在体内研究,心肌纤维排列松散，表现为炎症细胞浸润，在DM组中，线粒体cr破裂，GSDMD-NT表达显着增加，而xCT和GPX4的蛋白表达显著降低,两者都被MCC950逆转。高糖在体外降低细胞活力和ATP水平,伴随着LDH释放的增加。与单独处理的HG相比,在NLRP3敲低后所有上述指标均逆转。此外，成焦率和铁死亡相关因子的蛋白表达显著降低或升高，与免疫荧光显示的结果一致。此外，在mtROS激动剂鱼藤酮（ROT）治疗后，NLRP3敲低对HG的保护作用被逆转。总之,抑制NLRP3抑制DM诱导的心肌损伤。线粒体ROS的促进消除了敲低NLRP3的保护作用，并诱导了焦凋亡和铁凋亡的发生。这些发现可能为临床糖尿病引起的心肌损伤治疗提供了新的治疗基础机制。
