Pereira Camila A, Carlos Daniela, Ferreira Nathanne S, Silva Josiane F, Zanotto Camila Z, Zamboni Dario S, Garcia Valéria D, Ventura Dora Fix, Silva João S, Tostes Rita C
Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil.
Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil.
Front Physiol. 2020 Jan 17;10:1557. doi: 10.3389/fphys.2019.01557. eCollection 2019.
NLRP3 inflammasome activation in response to several signals, including mitochondrial DNA (mDNA), regulates inflammatory responses by caspase-1 activation and interleukin-1β (IL-1β) release. Circulating mDNA is linked to micro and macrovascular complications in diabetes. However, a role for mDNA in endothelial dysfunction is not clear. We tested the hypothesis that mDNA contributes to diabetes-associated endothelial dysfunction and vascular inflammation via NLRP3 activation. Vascular reactivity, reactive oxygen species (ROS) generation, calcium (Ca) influx and caspase-1 and IL-1β activation were determined in mesenteric resistance arteries from normoglicemic and streptozotocin-induced diabetic C57BL/6 and NLRP3 knockout ( ) mice. Endothelial cells and mesenteric arteries were stimulated with mDNA from control (cmDNA) and diabetic (dmDNA) mice. Diabetes reduced endothelium-dependent vasodilation and increased vascular ROS generation and caspase-1 and IL-1β activation in C57BL/6, but not in mice. Diabetes increased pancreatic cytosolic mDNA. dmDNA decreased endothelium-dependent vasodilation. In endothelial cells, dmDNA activated NLRP3 via mitochondrial ROS and Ca influx. Patients with type 1 diabetes exhibited increased circulating mDNA as well as caspase-1 and IL-1β activation. dmDNA activates endothelial NLRP3 inflammasome by mechanisms that involve Ca influx and mitochondrial ROS generation. NLRP3 deficiency prevents diabetes-associated vascular inflammatory damage and endothelial dysfunction. Our study highlights the importance of NLRP3 inflammasome in diabetes-associated vascular dysfunction, which is key to diabetic complications.
NLRP3炎性小体对包括线粒体DNA（mDNA）在内的多种信号作出反应而被激活，通过胱天蛋白酶-1激活和白细胞介素-1β（IL-1β）释放来调节炎症反应。循环中的mDNA与糖尿病的微血管和大血管并发症有关。然而，mDNA在内皮功能障碍中的作用尚不清楚。我们检验了这样一个假说，即mDNA通过NLRP3激活导致糖尿病相关的内皮功能障碍和血管炎症。在正常血糖和链脲佐菌素诱导的糖尿病C57BL/6和NLRP3基因敲除小鼠的肠系膜阻力动脉中测定血管反应性、活性氧（ROS）生成、钙（Ca）内流以及胱天蛋白酶-1和IL-1β激活情况。用来自对照（cmDNA）和糖尿病（dmDNA）小鼠的mDNA刺激内皮细胞和肠系膜动脉。糖尿病降低了C57BL/6小鼠的内皮依赖性血管舒张，并增加了血管ROS生成以及胱天蛋白酶-1和IL-1β激活，但在NLRP3基因敲除小鼠中未出现这种情况。糖尿病增加了胰腺细胞溶质中的mDNA。dmDNA降低了内皮依赖性血管舒张。在内皮细胞中，dmDNA通过线粒体ROS和Ca内流激活NLRP3。1型糖尿病患者循环中的mDNA以及胱天蛋白酶-1和IL-1β激活增加。dmDNA通过涉及Ca内流和线粒体ROS生成的机制激活内皮NLRP3炎性小体。NLRP3缺乏可预防糖尿病相关的血管炎性损伤和内皮功能障碍。我们的研究强调了NLRP3炎性小体在糖尿病相关血管功能障碍中的重要性，而这是糖尿病并发症的关键所在。
