Relationship between expression of caspase-activated DNase and neuronal injury during focal reversible ischemia in rat brain

Objective To investigate the relationship between the expression variations of caspase-activated DNase(CAD) protein and the neuronal apoptosis in rat cerebral cortex injured after focal cerebral ischemia-reperfusion with the intervention of caspase-3 inhibitor(Ac-DEVD-CHO) against neuronal injury.Methods The focal cerebral ischemia and reperfusion model was prepared by thread embolism of unilateral middle cerebral artery(MCA).The expression of protein and neuronal apoptosis in the temporal parietal cortex regions injured by ischemia for 1 h then reperfusions at 6,12,24,48,72 h points were stu-died by using HE staining,immunohistochemistry,in situ apoptotic detection(TUNEL method) and electron microscope technique.And then the effects of caspase-3 inhibitor given via intraventricular injection on these variations were also assessed.Results In ischemia-reperfusion group,the change of apoptotic cells was accordant with that of protein expression.As for the treatment group,the trend of above parameters tends to be mild,and the peak expression of these parameters were lower than that in ischemia and reperfusion group after 6 h point.Conclusion The expression of caspase-3 followed by the activated of CAD protein participates the process of neuronal apoptosis in rat brains subjected to transient focal cerebral ischemia.Treatment with caspase-3 inhibitor to a certain extent inhibits the activation of caspases-3 and CAD,reduces the number of apoptotic cell after focal cerebral ischemia and reperfusion,thus plays a protective role in ischemic brain damage.