摘要
目的动态观察大鼠肝缺血再灌注(HIRI)不同时限葡萄糖调节蛋白78(GRP78)、葡萄糖调节蛋白94(GRP94)、磷酸化蛋白激酶B1(p-Akt1)及半胱氨酰天冬氨酸特异性蛋白酶12(Caspase-12)的表达变化,并探讨其意义。方法将55只Wistar雄性大鼠随机分为正常组(n=5)、假手术组(n=25)、缺血再灌注组(n=25),无损伤动脉钳阻断肝血流45min后使其复流,用免疫组织化学法检测GRP78、GRP94及Caspase-12在再灌注0、3、12、24、72h时的蛋白表达,用Western blot法检测同期p-Akt1蛋白表达。结果GRP78在缺血再灌注组的表达显著高于正常组与假手术组(P〈0.01),在缺血再灌注0h时表达开始上升(393.04±79.06),12h时达峰值(2369.38±182.53),24h(1023.02±185.61)及72h(505.19±102.89)表达开始下降,但仍高于前述各组表达水平。GRP94在缺血再灌注组的表达显著高于正常组与假手术组(P〈0.01),在缺血再灌注0h时表达开始上升(168.47±21.08),12h时达峰值(678.80±52.62),24h(425.78±38.63)及72h(173.99±36.82)表达降低。Caspase-12在缺血再灌注组的表达显著高于正常组与假手术组(P〈0.01),在缺血再灌注0h时表达开始上升(647.00±73.68),12h达峰值(6867.67±601.11),24h(2356.12±210.65)及72h(675.89±109.3)表达开始降低。p-Akt1在缺血再灌注组各观察时限点的表达趋势与GRP78一致,显著高于正常组及假手术组。结论大鼠肝缺血再灌注损伤可触发经内质网途经的Caspase级联反应活化;GRP78与GRP94可能通过降低内质网负荷和促进糖异生而发挥细胞保护作用;p-Akt1可能是此过程中机体通过磷酸肌醇3激酶(P13K)/Akt信号通路上调GRP78表达的重要信号分子。
Objective To dynamically observe the changes of glucose regulated protein 78 (GRP78),glucose regulated protein 94 (GRP94),p-protein kinase B1 (p-Akt1) and Caspase-12 expression during the periods of hepatic ischemia/reperfusion (I/R) in rats.Methods Fifty-five Wistar rats were randomly divided into 3 groups:normal control group (n =5),sham operated group (n =25) and I/R group (n =25).The rat model of hepatic I/R was established by clamping hepatic pedicle for 45 min by using no damage artery clamp and then reperfusion.The expression of GRP78,GRP94 and Caspase-12 was detected by using immunohistochemistry SABC at 0,3,12,24-and 72 h after I/R.The expression of p-Akt1 was detected by using Western blotting at the same time points.Results The expression levels of GRP78,GRP94 and Caspase-12 in I/R group were significantly higher than in normal control group and sham operated group (P <0.01).In I/R group,the expression of GRP78 was increased at 0 h (393.04±79.06) after reperfusion,peaked at 12 h (2369.38 ± 182.53),and began to decline at 24 h (1023.02 ± 185.61) and 72 h (505.19 ± 102.89),but still significantly higher than the other two groups.In I/R group,the expression of GRP94 was increased at 0 h (168.47 ±21.08) after reperfusion,peaked at 12 h (678.8 ±52.62),and hegan to decline at 24 h (425.78 ±38.63) and 72 h (173.99 ±36.82).In I/R group,the expression of Caspase-12 was increased at 0 h (647±73.68) after reperfusion,peaked at 12 h (6867.67 ± 601.11),and began to decline at 24 h (2356.12 ±210.65) and 72 h (675.89 ± 109.3).The expression trend of p-Aktl resembled GRP78 in I/R group at different time points,and significantly higher than the other two groups.Conclusion Hepatic I/R injury can activate Caspase cascade reaction via the endoplasmic reticulum.GRP78 and GRP94 may play a protective effect during the periods of hepatic I/R in rats by reducing the burden of endoplasmic reticulum and promoting gluconeogenic pathway.p-Akt1 probably is an important signal molecule in the phosphatidylinositol 3 kinase (PI3K)/Akt signal path by which the expression of GRP78 is up-regulated.
出处
《中华实验外科杂志》
CAS
CSCD
北大核心
2013年第5期940-943,共4页
Chinese Journal of Experimental Surgery
基金
基金项目:国家自然科学基金资助项目(81170420)