Department of Neurology, Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China.
Curr Neurovasc Res. 2013 Aug;10(3):208-15. doi: 10.2174/15672026113109990006.
Ischemic stroke causes a significant amount of cell damage resulting from an insufficient supply of glucose and oxygen to central nervous system tissue and finding more effective therapeutic neuroprotective agents has become a priority in the treatment of ischemic stroke. Hsp20, one of the small heat shock proteins, has been implicated in multiple physiological and pathophysiological processes and is a potential neuroprotective agents. To investigate whether Hsp20 exerts protective effects on in vitro ischemia-reperfusion injury, mouse neuroblastoma cells were subjected to oxygen-glucose deprivation/reoxygenation (OGDR) insult. The N2a cells transfected with Hsp20 and constitutively phosphorylated Hsp20 (S16D) had significantly less cell loss and less proportion of apoptotic cells compared to N2a cells transfected with pEGFP-N1 after oxygen-glucose deprivation (OGD) 4 h plus 12 and 24 h reperfusion, which showed no difference in N2a cells transfected with nonphosphorylatable Hsp20 (S16A). Meanwhile, transfected with Hsp20 and constitutively phosphorylated Hsp20 (S16D) also significantly attenuated mitochondrial fragmentation and modulated Bcl-2 and Bax expression level after OGD 4 h plus 12 reperfusion, which were not affected in N2a cells transfected with Hsp20 (S16A). In conclusion, our data demonstrated that increased Hsp20 and Hsp20 (S16D) expression in mouse N2A neuroblastoma cells protected against ischemia-reperfusion injury, the neuroprotective mechanism may be related to regulate Bcl-2 and Bax expression. However, blockade of Ser16-Hsp20 phosphorylation attenuated the neuroprotective effects of Hsp20. Therefore, Hsp20 and factors that contribute to regulation of phosphorylation on Ser16 of Hsp20 are potential new therapeutic targets for the treatment of cerebral ischemia-reperfusion injury.
缺血性中风会导致中枢神经系统组织因葡萄糖和氧气供应不足而造成大量细胞损伤，因此寻找更有效的治疗神经保护剂已成为治疗缺血性中风的首要任务。热休克蛋白 20（Hsp20）是一种小分子热休克蛋白，与多种生理和病理生理过程有关，是一种有潜力的神经保护剂。为了研究 Hsp20 是否对体外缺血再灌注损伤具有保护作用，将小鼠神经母细胞瘤细胞进行氧葡萄糖剥夺/再复氧（OGDR）处理。与转染 pEGFP-N1 的 N2a 细胞相比，转染 Hsp20 和组成性磷酸化 Hsp20（S16D）的 N2a 细胞在氧葡萄糖剥夺（OGD）4 小时后再灌注 12 小时和 24 小时时细胞丢失明显减少，且凋亡细胞比例也明显减少，而转染非磷酸化 Hsp20（S16A）的 N2a 细胞则无差异。同时，转染 Hsp20 和组成性磷酸化 Hsp20（S16D）也明显减轻了线粒体碎片化，并在 OGD 4 小时后再灌注 12 小时时调节了 Bcl-2 和 Bax 的表达水平，而转染 Hsp20（S16A）的 N2a 细胞则不受影响。综上所述，我们的数据表明，在小鼠 N2A 神经母细胞瘤细胞中增加 Hsp20 和 Hsp20（S16D）的表达可防止缺血再灌注损伤，其神经保护机制可能与调节 Bcl-2 和 Bax 的表达有关。然而，Ser16-Hsp20 磷酸化的阻断削弱了 Hsp20 的神经保护作用。因此，Hsp20 和促进 Ser16 磷酸化的因素可能是治疗脑缺血再灌注损伤的新的潜在治疗靶点。
