Kir6.1介导的线粒体钙调控在糖尿病心肌病心律失常中的作用及其分子机制研究

糖尿病心肌病患者易发生心律失常。Kir6.1在糖尿病心肌病进展中具有重要作用，Kir6.1作为线粒体膜通道蛋白影响线粒体功能，可能参与糖尿病心肌病心律失常发生，但其机制尚不清。本课题组前期研究发现，糖尿病心肌病小鼠Kir6.1表达量降低，线粒体结构紊乱和功能障碍，细胞内钙离子紊乱。据此假设Kir6.1通过影响线粒体功能导致细胞内钙紊乱，诱发心律失常。为验证此假说，通过心脏特异性敲除Kir6.1，观察其对心脏功能和心电活动影响，通过流式细胞仪、生物能量测定仪探讨Kir6.1对线粒体膜电势及能量代谢影响，共聚焦显微镜观察线粒体基质钙及胞内钙动力学变化，并检测钙调蛋白表达量，采用膜片钳技术观察离子流、动作电位参数及触发活动发生。进一步过表达Kir6.1验证其对线粒体钙调控作用，通过探讨Kir6.1介导线粒体钙调控在糖尿病心肌病心律失常中的作用及其分子机制，为糖尿病心肌病心律失常治疗提供新靶点。

Diabetic cardiomyopathy patients are prone to arrhythmia. Kir6.1 plays an important role in the progression of diabetic cardiomyopathy. As a mitochondrial membrane channel protein, it affects mitochondrial function and may be involved in the occurrence of arrhythmias in diabetic cardiomyopathy, but the mechanism is still unclear. Our previous study found that the expression level of Kir6.1 in diabetic cardiomyopathy mice was decreased, leading mitochondrial structural disorder and dysfunction, and intracellular calcium ions disorder. Therefore, it is hypothesized that Kir6.1 cause intracellular calcium disorder by affecting mitochondrial function and induce arrhythmia.So, this study observe the effect of Kir6.1 on cardiac function and electrical activity by knockout cardiac-specific Kir6.1 with diabetic cardiomyopathy mice. Through flow cytometry meter and bioenergy analyzer to detect Kir6.1 effect on mitochondrial membrane potential and energy metabolism. Mitochondrial matrix calcium and intracellular calcium dynamics are observed by confocal microscopy. The expression levels of calcium-related proteins are detected. Patch clamp technique is used to observe ion flow, action potential parameters and triggering activity. Furthermore, overexpression of Kir6.1 is used to verify its effect on mitochondrial calcium regulation. All the above, to explore the role of Kir6.1 mediated mitochondrial calcium regulation in diabetic cardiomyopathy arrhythmia and its molecular mechanisms.It will provide a new target for the clinical treatment of arrhythmia with diabetic cardiomyopathy.