气体分子硫化氢调控线粒体重塑影响糖尿病动脉内皮细胞线粒体自噬发生的机制

Vascular diseases in patients with diabetes mellitus (DM) are also associated with oxidative stress of endothelial cells (ECs), in particular with an overproduction of reactive oxygen species in mitochondria, however, its mechanisms are unclear. H2S can be produced by cystathionine r-lyase (CSE) in ECs which can inhibit production of reactive oxygen.H2S plays a role in relaxing artery, antioxidation and anti-apoptosis. Our previous studies have shown that CSE activity was decreased, ROS was overproduced in mitochondria of endothelial cells in diabetic mice. Exogenous H2S inhibits ROS level in mitochondria and promotes mitochondrial fusion. Therefore, we postulate " H2S plays a protective role through maintaining ATP level and promoting mitochondrial fusion and decreasing mitochondrial fission and mitophage and apoptosis in diabetic mice model." We will observe the changes of H2S content and CSE activity in CSE wild type and knock out diabetic mice, which effects on mitochondrial fission and fusion and mitophage and apoptosis. The goal of this study is to investigate the protective role and its mechanisms of H2S and to provide a new idea to therapy in diabetic peripheral angiopathy.

糖尿病周围血管病是糖尿病的重要并发症，高血糖引起线粒体功能异常诱发动脉内皮细胞损伤，但机制不清。内皮细胞通过胱硫醚-γ-裂解酶（CSE）催化产生气体分子-H2S。研究发现，H2S具有舒张动脉、抗氧化及抗凋亡作用。前期我们证实，糖尿病内皮细胞CSE活性降低，线粒体ROS产生增多；给予外源性H2S，ROS产生减少，并促进线粒体融合发生。据此，我们推测"H2S是糖尿病动脉内皮细胞保护作用的信号分子，H2S通过维持线粒体ATP水平，调控线粒体重塑（即线粒体融合与分裂动态变化）、影响线粒体自噬及凋亡，进而启动糖尿病内皮细胞的保护作用"。本课题观察CSE野生及敲除型糖尿病小鼠及高糖处理的动脉内皮细胞中CSE活性及H2S含量变化，重点关注其对线粒体重塑、线粒体自噬和凋亡及线粒体能量代谢和呼吸功能的影响。本课题在器官、细胞、线粒体及分子水平上探讨H2S发挥保护作用的机制，为糖尿病周围血管病的防治提供新思路

糖尿病周围血管病是糖尿病的重要并发症，高血糖引起的线粒体功能异常诱发内皮细胞损伤，但其机制不清，内皮细胞通过胱硫醚-γ-裂解酶（CSE）催化产生气体分子—H2S。在前期结果的基础上，本课题推测“H2S是糖尿病动脉内皮细胞保护作用的信号分子，其通过维持线粒体ATP水平，调控线粒体的融合与分裂，影响线粒体自噬及凋亡，进而启动糖尿病内皮的保护作用”。本课题采用STZ诱导I型糖尿病大鼠及db/db小鼠模型II型糖尿病动物模型，动态观察主动脉CSE的表达及H2S的含量变化及动脉粘附功能改变，采用高糖高脂处理大鼠胸主动脉内皮细胞复制糖尿病细胞模型。给予外源性H2S，线粒体ROS生成抑制剂，细胞内ROS清除剂，CSE抑制剂，线粒体分裂抑制剂，AMPK siRNA，Atg7 siRNA和Mfn-2 siRNA转染等多种手段。本课题证实（1）高糖高脂诱导动脉内皮细胞CSE-H2S生成系统活性下降；（2）外源性H2S调控AMPK信号转导通路的活性，促进动脉血管内皮细胞自噬的发生。（3）在器官、细胞及分子水平上证明H2S调控线粒体分裂与融合，促进线粒体自噬的发生，减少内皮细胞凋亡的发生。