Expression and significance of Homer1a protein in cerebral cortex after ischemic reperfusion injury of brain in rats

Objective To investigate the expression and significance of Homer1a protein in cerebral cortex after ischemic reperfusion injury of brain in rats.Methods Fifty-four adult SD rats were randomized into nine groups with 6 rats in each group:normal control group and post-ischemic groups of 10 min,1 h,3 h,6 h,12 h,24 h,48 h and 72 h after ischemic brain injury.The expressions of Homer1a were investigated by immunohistochemistry,immunoblotting and RT-PCR.Results Forty-nine rats were studied with five rats excluded due to their death during the study.It was shown that compared with the control group,there were three peak levels of expression of the gray value of Homer1a protein and mRNA following ischemic reperfusion brain injury,at 10 min,6 h and 24 h.The levels remains high at 72 h with mild decrease.The immunoreactivity score of Homer1a protein expression showed two peak values respectively at 6 h and 24 h after ischemic reperfusion brain injury;Homer1a protein expression was also detected in glia cells besides neurons.Conclusions After ischemic reperfusion brain injury,there are three peak levels of expression of Homer1a which may play important roles in the development of brain injury via different mechanism.