CAJ | 학술논문

目的：探讨低温刺激诱导心肌细胞损伤及凋亡，以及细胞外信号调节蛋白激酶5（ERK5）/凋亡调节蛋白Bim途径的调控作用。 　　方法：基于乳鼠原代心肌细胞，低温培养箱施加低温刺激；使用特异性小干扰RNA（siRNA）下调ERK5或Bim的表达；细胞凋亡使用流式细胞仪检测；各蛋白表达水平通过Western blot检测；细胞内钙离子、活性氧簇（ROS）水平、线粒体膜电位（ΔΨm）通过荧光标记及流式细胞仪检测。 　　结果：在低温刺激下的心肌细胞中，ERK5 siRNA可加剧Bim蛋白表达；Bim siRNA不影响ERK5，但减轻p-ERK5表达；ERK5 siRNA导致更高的细胞凋亡率，Bim siRNA则可减弱ERK5 siRNA的促凋亡作用；ERK5 siRNA加重了细胞内钙离子超载、ROS激活、线粒体膜电位破坏，Bim siRNA则可对抗上述损伤性作用。 　　结论：在低温干预下的心肌细胞中，下调ERK5可释放对Bim的表达抑制，加重凋亡、细胞内钙离子超载、ROS爆发，造成更严重的线粒体膜电位破坏，而下调Bim则产生反向的保护作用。结果显示ERK5/Bim途径在低温诱导心肌细胞损伤中的重要调控作用。
목적：탐토저온자격유도심기세포손상급조망，이급세포외신호조절단백격매5（ERK5）/조망조절단백Bim도경적조공작용。 　　방법：기우유서원대심기세포，저온배양상시가저온자격；사용특이성소간우RNA（siRNA）하조ERK5혹Bim적표체；세포조망사용류식세포의검측；각단백표체수평통과Western blot검측；세포내개리자、활성양족（ROS）수평、선립체막전위（ΔΨm）통과형광표기급류식세포의검측。 　　결과：재저온자격하적심기세포중，ERK5 siRNA가가극Bim단백표체；Bim siRNA불영향ERK5，단감경p-ERK5표체；ERK5 siRNA도치경고적세포조망솔，Bim siRNA칙가감약ERK5 siRNA적촉조망작용；ERK5 siRNA가중료세포내개리자초재、ROS격활、선립체막전위파배，Bim siRNA칙가대항상술손상성작용。 　　결론：재저온간예하적심기세포중，하조ERK5가석방대Bim적표체억제，가중조망、세포내개리자초재、ROS폭발，조성경엄중적선립체막전위파배，이하조Bim칙산생반향적보호작용。결과현시ERK5/Bim도경재저온유도심기세포손상중적중요조공작용。
Objective: To explore the regulative role of extracellular regulated protein kinase-5 (ERK5)/Bcl-2 interacting mediator of cell death (Bim) pathway in hypothermal stimulation induced neonatal rat’s cardiomyocytes (CMs) damage and apoptosis. Methods: CMs were cultured for hypothermal stimulation and the speciifc siRNA was used to down-regulate the ERK5 or Bim in CMs. The cell apoptosis was detected by lfow cytometry, protein expression was examined by Western blot analysis, the intracellular Ca2+, reactive oxygen species (ROS) and mitochondrial membrane potential (ΔΨm) were evaluated by lfuorescent labeling and lfow cytometry. Results: In hypothermal stimulated CMs, ERK5 siRNA could promote Bim protein expression, but Bim siRNA could not inlfuence ERK5, while attenuated p-ERK5 expression. ERK5 siRNA induced higher apoptosis rate, while Bim siRNA could decrease such effect. ERK5 siRNA increased the intracellular Ca2+overloading, ROS activation andΔΨm damage, while Bim siRNA played the role to against those effects in hypothermal stimulated CMs. Conclusion: Our study revealed that ERK5/Bim pathway played the important regulative roll in hypothermal stimulation induced neonatal rat’s CMs damage and apoptosis.