SIRT1调控内质网应激在蛛网膜下腔出血后早期脑损伤中的作用研究

Role of SIRT1 in regulating endoplasmic reticulum stress in early brain injury after subarachnoid hemorrhage

目的探讨Sirtuin 1(SIRT1)调控内质网应激在蛛网膜下腔出血(SAH)后早期脑损伤中的作用。方法采用颈内动脉穿刺的方法构建小鼠SAH模型。Western Blot和实时荧光定量PCR检测SAH后0、3、6、12、24、48、72 h SIRT1的蛋白和mRNA的表达水平,给予SIRT1抑制剂sirtinol或SIRT1小干扰RNA(siRNA)后Western Blot检测SIRT1和内质网应激相关标志物葡萄糖调节蛋白78(GRP78)、磷酸化蛋白激酶R样内质网激酶(p-PERK)/PERK、磷酸化真核细胞翻译起始因子2α(p-eIF2α)/eIF2α和C/EBP同源蛋白(CHOP)的表达水平及SAH后24 h检测SAH评分、神经功能评分、脑含水量和血脑屏障完整性。结果与其他时间点相比,在24 h时,SIRT1蛋白和mRNA的表达最高,其差异有统计学意义(均P<0.001)。抑制SIRT1表达后内质网应激相关的蛋白GRP78、p-PERK/PERK、p-eIF2α/eIF2α和CHOP表达量增加,加剧出血量和脑含水量、破坏血脑屏障完整性,显著降低神经功能评分。结论抑制SIRT1表达显著增加内质网应激发反应,加剧SAH后的早期脑损伤。

Objective To investigate the effect of Sirtuin 1(SIRT1)on subarachnoid hemorrhage(SAH)and its possible mechanism.Methods A mouse model of SAH was constructed by internal carotid artery puncture.The protein and mRNA expression levels of SIRT1 at 0,3,6,12,24,48,and 72 h were detected by Western Blot and qRT-PCR.A Western Blot assay was used to examine SIRT1 and the expression levels of endoplasmic reticulum stress-related markers GRP78,p-PERK/PERK,p-eIF2α/eIF2α,and CHOP after administration of a SIRT1 inhibitor or SIRT1 si-RNA.At 24 h after SAH,subarachnoid hemorrhage volume,neurological function score,brain water content,and blood-brain barrier integrity were measured.Results The highest expression of SIRT1 protein and mRNA was observed at 24 h compared with other time points,and the differences were statistically significant(all P<0.001).Inhibition of SIRT1 expression leads to increased expression of endoplasmic reticulum stress-related proteins GRP78,p-PERK/PERK,p-eIF2α/eIF2α,and CHOP,exacerbating hemorrhage and brain water content,disrupting blood-brain barrier integrity,and significantly reducing neurological function scores.Conclusions Inhibition of SIRT1 expression significantly increased the endoplasmic reticulum response to excitation and exacerbated early brain injury after SAH.