Effect of mild hypothermia on expression of small ubiquitin-like modifier-specific proteases 3 in brain tissues during cerebral ischemia-reperfusion in mice

Abstract

Objective To investigate the effect of mild hypothermia on the expression of small ubiquitin-like modifier-specific proteases 3(SENP3)in the brain tissues during cerebral ischemia-reperfusion(I/R)in mice. Methods Ninety-six male C57/BL6 mice, aged 10-12 weeks, weighing 22-30 g, were randomly divided into 3 groups(n=32 each)using a random number table: sham operation group(group S), group I/R, and mild hypothermia group(group H). Cerebral I/R was produced by occlusion of bilateral common carotid arteries for 15 min followed by reperfusion.The surface cooling was started immediately after reperfusion, and the rectal temperature was maintained at 32-34 ℃ for 3 h. At 6, 12, 24 and 72 h of reperfusion, 8 mice were selected from each group and sacrificed.The hippocampi were removed for examination of the pathological changes(with light microscope)and for determination of cell apoptosis(using TUNEL)and expression of SENP3(by Western blot). The apoptosis rate was calculated. Results Compared with group S, the apoptosis rate in hippocampal CA1 region was significantly increased, and the expression of SENP3 was significantly up-regulated at each time point of reperfusion in group I/R(P<0.05). Compared with group I/R, the apoptosis rate in hippocampal CA1 region was significantly decreased, and the expression of SENP3 was significantly down-regulated at each time point of reperfusion(P<0.05), and the pathological changes were significantly reduced in group H. Conclusion The mechanism by which mild hypothermia reduces cerebral I/R injury is associated with inhibition of SENP3 expression in the brain tissues of mice. Key words: Hypothermia, induced; Cysteine endopeptidases; Reperfusion injury; Brain