JAK2/STAT3通路介导热休克蛋白70对脑出血的神经保护作用

The neuroprotective effect of heat shock protein 70 through the JAK2/STAT3 signaling pathway in cerebral hemor-rhage

目的观察蛋白酪氨酸激酶2/信号转导和转录激活因子3(janus kinase 2-signal transducer and activator of transcription 3,JAK2/STAT3)信号通路特异性拮抗剂α-氰基-(3,4-羟基)N-苄苯乙烯胺〔alpha cyano-(3-hydroxy)N-styrene benzyl amine,AG-490〕对脑出血大鼠脑组织热休克蛋白70(heat shock protein 70,HSP70)、磷酸化蛋白酪氨酸激酶2(phosphorylated janus kinase 2,P-JAK2)、磷酸化信号转导和转录激活因子3(phosphorylated signal transducer and activator of transcription 3,P-STAT3)表达的影响,并分析HSP70与PJAK2、P-STAT3的相关性,探讨JAK2/STAT3信号通路是否介导HSP70对大鼠脑出血后的神经保护作用。方法将健康雄性Sprague-Dawley(SD)大鼠100只随机分为正常组、假手术组、脑出血和AG-490组;采用大鼠自体血注入法建立脑出血模型;各组按造模成功后时间分为6h、24h、48h、72h、7d共5个亚组,对各组大鼠进行神经功能缺损评分(neurological severity scores,NSS);免疫组化染色检测血肿周围HSP70表达,采用Western blot检测大鼠血肿周围脑组织P-JAK2、P-STAT3的表达。结果脑出血组和AG-490组HSP70、P-JAK2、PSTAT表达均高于假手术组和正常组(P<0.05),并于造模后48h达高峰(P<0.05);AG-490组HSP70、PJAK2、P-STAT表达较脑出血组低(P<0.05);脑出血组HSP70表达与NSS评分呈负相关(r=-0.511,P<0.05),HSP70表达与P-JAK2、P-STAT3的表达呈正相关(r=0.790,P<0.05;r=0.447,P<0.05)。结论 JAK2/STAT3信号通路可能通过上调HSP70的表达进而对大鼠脑出血后起神经保护作用。

Objective To investigate the effect of Alpha cyano-（3-hydroxy）N-styrene benzyl amine（AG-490）[the janus kinase 2-signal transducer and activator of transcription 3（JAK2/STAT3）signaling pathways specific antagonist]on the expression of heat shock protein 70（HSP70）,phosphorylated janus kinase 2（P-JAK2）and activator of transcription 3（P-STAT3）in cerebral hemorrhage rat models,and the correlation between the JAK2/STAT3 signaling pathway and the expression of HSP70.To investigate the role of JAK2/STAT3 signal pathway and HSP70 in neuroprotective effects of cerebral hemorrhage rats.Methods One hundred healthy male Sprague-Dawley rats were randomly divided into four groups：the normal group,the sham operation group,the cerebral hemorrhage group and the AG-490 group.The autologous arterial blood was stereotaxically injected to the right caudate nucleus to establish cerebral hemorrhage rat models.According to the different sacrificed time,every group was divided into 5subgroups：6h,24 h,48h,72 h,7d.The rats were evaluated by the neurological deficit scores（Neurological Severity Scores,NSS）,the expressions of HSP70,PJAK2,and P-STAT3 were detected by immunostaining and Western blot using rat brain tissue around the hematoma.Results HSP70,P-JAK2 and P-STAT expressions in the cerebral hemorrhage group and the AG-490 group were higher than those of the sham group and the normal group（P〈0.05）,and 48 hafter modeling their expressions reached a peak（P〈0.05）.HSP70,P-JAK2 and P-STAT expressions in the AG-490 group were lower than those of the cerebral hemorrhage group（P〈0.05）.NSS and HSP70 expression were negatively correlated（r=-0.511,P〈0.05）,HSP70 expression was positively correlated with P-JAK2 and P-STAT3expression（r=0.790,P〈0.05;r=0.447,P〈0.05）in the cerebral hemorrhage group.Conclusions JAK2/STAT3 signaling pathway may play a role in neuroprotection after cerebral hemorrhage by upregulating the expression of HSP70.