The changes of expressions of the endoplasmic reticulum chaperones GRP78, GRP94, and caspase-12 following cerebral ischemia in rats / 中国脑血管病杂志

ABSTRACT

Objective: To observe the expressions of glucose-regulated protein (GRP) 78, GRP94 and caspase-12 related with endoplasmic reticulum in the striatum during focal cerebral ischemia in rats, so as to investigate the possible effect of endoplasmic reticulum molecular chaperones and apoptosis factor in the ischemic process. Methods: Sixty rats were equally randomized into 2 groups (n = 30) The sham operated group and the ischemic group (focal transient cerebral ischemia model was established with intraluminal occlusion of left meddle cerebral artery). The expression of GRP78, GRP94 and caspase-12 in rats striatum was detected by immunohistochemistry staining and semiquantitative RT-PCR at the different time points (6, 12 and 24 h after ischemia). Results: Immunohistochemistry staining and RT-PCR results illustrated that the mRNAs and protein expressions of GRP78 and GRP94 in ischemic group were lower than that in sham operated group at each time point (P < 0.05). The expression of the GRP78 and GRP94 were highest at 12 h from 6 h to 24 h (P < 0.05) in ischemic group. The expression of caspase-12 in ischemic group upgrade at 6 h and were highest at 12 h and decreased at 24 h. There was no expression in sham operated group. Conclusion: Endoplasmic reticulum-self regulated system was started through the increased expressions of GRP78 and GRP94 after striatum ischemia in rats, so as to attenuated cerebral ischemic injury. Endoplasmic reticulum-self regulated function loss because of severe cerebral ischemia. Initiation of caspase-12 apoptosis pathway is possible one of the mechanisms that priming endoplasmic reticulum apoptosis pathway in cerebral ischemic injury.