Zhu Yan-hui, Wang Xian
Department of Physiology and Pathophysiology, Basic Medical College, Key Laboratory of Molecular Cardiovascular Biology, Ministry of Education, Peking University, Beijing 100083, China.
Acta Pharmacol Sin. 2005 Sep;26(9):1076-80. doi: 10.1111/j.1745-7254.2005.00137.x.
To explore whether overexpression of the small heat shock protein HSP20 in rat cardiomyocytes protects against simulated ischemia/reperfusion (SI/R) injury.
Recombinant adenovirus expressing HSP20 was used to infect rat H9c2 cardiomyocytes at high efficiency, as assessed by green fluorescent protein. H9c2 cells were subjected to SI/R stress; survival was estimated through assessment of lactate dehydrogenase and cell apoptosis through caspase-3 activity.
Overexpression of HSP20 decreased lactate dehydrogenase release by 21.5% and caspase-3 activity by 58.8%. Pretreatment with the protein kinase C inhibitor Ro-31-8220 (0.1 micromol/L) for 30 min before SI/R canceled the protective effect of HSP20. The selective mitochondrial K+ATP channel inhibitor 5-hydroxydecanoate (100 micromol/L) had a similar effect. However, the non-selective K+ATP channel inhibitor glibenclamide (100 micromol/L) had no significant effect.
These data indicate that the protective effect of HSP20 in vitro is primarily due to reduced necrotic and apoptotic death of cardiomyocytes, possibly via the protein kinase C/mitochondrial K+ATP pathway.
探讨大鼠心肌细胞中小热休克蛋白HSP20的过表达是否能预防模拟缺血/再灌注（SI/R）损伤。
用表达HSP20的重组腺病毒高效感染大鼠H9c2心肌细胞，通过绿色荧光蛋白进行评估。对H9c2细胞施加SI/R应激；通过评估乳酸脱氢酶来估计细胞存活情况，通过半胱天冬酶-3活性评估细胞凋亡情况。
HSP20的过表达使乳酸脱氢酶释放减少21.5%，半胱天冬酶-3活性降低58.8%。在SI/R之前用蛋白激酶C抑制剂Ro-31-8220（0.1微摩尔/升）预处理30分钟可消除HSP20的保护作用。选择性线粒体K+ATP通道抑制剂5-羟基癸酸（100微摩尔/升）有类似作用。然而，非选择性K+ATP通道抑制剂格列本脲（100微摩尔/升）没有显著作用。
这些数据表明，HSP20在体外的保护作用主要是由于心肌细胞坏死和凋亡死亡减少，可能是通过蛋白激酶C/线粒体K+ATP途径实现的。
