内质网应激-CaMK II-凋亡通路介导分子氢心脏保护作用机制的研究

Endoplasmic reticulum stress (ERS)-calmodulin dependent protein kinaseII (CaMKII) pathway plays a pivotal role in myocardial ischemia reperfusion (I/R) injury. ROS interacted with ERS in IR plays a key role in process. Formal studies showed that hydrogen can protect IR injury by inhibit the over activation of ROS. Our previous research demonstrated that hydrogen could protect against myocardial I/R injury by relieving ERS, reduced calcium influx, imply that hydrogen might mitigate calcium overload through ERS-CaMKII pathway. This study is designed to investigate the effect of hydrogen on ERS-CaMKII pathway on the I/R injury model as well as on the hypoxia/ reoxygenation cultured myocyte model. We try to identify how hydrogen affect ERS-CaMKII pathway by using the suppressors, and put emphasis on knockdown and over expression of ERS related gene(CHOP) in cultured myocytes. The aim is to elucidate whether hydrogen could inhibit myocyte calcium overload by attenuating ERS-CaMKII pathway to conduct myocardial protective. Results gained from this study will light the probably mechanism of hydrogen regulating myocyte ERS induced IR injury. It will provide new vision and help with the development of novel therapies for clinical cardioprotection.

内质网应激（ERS）引起的CaMKII过表达是心肌缺血再灌注（IR）损伤发生和发展的枢纽性环节，活性氧（ROS）与ERS的相互作用在IR的发生发展过程中扮演着关键角色。既往的研究表明：分子氢可以通过抑制ROS的过度激活发挥对再灌注损伤的保护作用；而我们的前期研究证实：氢在IR过程中可减轻内质网应激，减少钙内流，缓解钙超载，发挥对IR损伤的保护作用，提示氢可能通过ERS-CaMKII通路，减少钙内流，发挥对再灌注损伤的保护作用。本项目拟在已成功建立的心肌IR损伤模型和细胞缺氧/复氧模型基础上，应用相关通路抑制剂，研究分子氢在IR过程中对ERS-CaMKII通路的作用，重点探讨沉默或过表达ERS相关基因（CHOP等）对分子氢抑制心肌细胞钙超载的影响，明确其是否可通过ERS-CaMKII通路，减少心肌细胞钙超载的发生，发挥其心脏保护作用。

内质网应激（ERS）引起的CaMKII过表达是心肌缺血再灌注（IR）损伤发生和发展的枢纽性环节，活性氧（ROS）与ERS的相互作用在IR的发生发展过程中扮演着关键角色。既往的研究表明：分子氢可以通过抑制ROS的过度激活发挥对再灌注损伤的保护作用；而我们的前期研究证实：氢在IR过程中可减轻内质网应激，减少钙内流，缓解钙超载，发挥对IR损伤的保护作用，提示氢可能通过ERS-CaMKII通路，减少钙内流，发挥对再灌注损伤的保护作用。本项目拟在已成功建立的心肌IR损伤模型和细胞缺氧/复氧模型基础上，应用相关通路抑制剂，研究分子氢在IR过程中对ERS-CaMKII通路的作用，重点探讨沉默或过表达ERS相关基因（CHOP等）对分子氢抑制心肌细胞钙超载的影响，明确其是否可通过ERS-CaMKII通路，减少心肌细胞钙超载的发生，发挥其心脏保护作用。本研究发现：1、心肌IR能激活ERS，增加心肌细胞的凋亡；2、H2可通过减轻心肌IR后ERS，下调CHOP表达，降低CaMKⅡ的氧化激活，减少细胞凋亡；3、H2影响心肌细胞凋亡的具体机制与CaMKⅡ介导细胞内Ca2+超载有关。