高压氧预处理减少局灶性脑缺血后泛素化蛋白聚集

Hyperbaric oxygen preconditioning reducing conjugated-ubiquitin accumulation after focal brain ischemia

目的探讨泛素-蛋白酶体系统在重复高压氧(HBO)预处理导致的脑缺血耐受中所起的作用。方法采用大脑中动脉阻闭(MCAO)制备大鼠局灶性脑缺血模型,将33只SD大鼠随机分为假手术组(Sham)组、MCAO组和HBO组,分别观察各组大鼠脑梗死灶的大小和神经功能学评分,并用免疫组织化学染色检测再灌注2h、24h时相点大鼠脑组织CA1区异常泛素化蛋白聚集的变化。结果 HBO组脑梗死容积小于MCAO组,差异有统计学意义(P<0.05),其神经功能学评分也明显优于MCAO组(P<0.05)。再灌注各时相点,HBO组泛素化蛋白聚集明显少于MCAO组(P<0.05)。结论高压氧预处理所诱导的脑缺血耐受的机制可能与泛素化蛋白聚集降低有关。

Objective To investigate the role of ubiquitin-proteasome system in cerebral ischemic tolerance induced by repeated hyperbaric oxygen （HBO） preconditioning in rats.Methods Focal rat brain ischemic model was established by middle cerebral artery occlusion （MCAO）. Thirty-three rats were randomly divided into 3 groups： sham group,MCAO group and HBO group. The brain infarct volume and the neurologic deficit scores of all groups were measured and the conjugated-ubiquitin accumulation in hippocampal CA1 region was measured by using immunohistochemical staining at 2 h and 24 h after reperfusion.Results In HBO group,the infarct volume was significantly smaller than that in MCAO group （P0.05）,and the neurologic deficit scores were improved compared to MCAO group （P0.05）; ubiquitin protein accumulation was significantly alleviated in HBO group compared with MCAO group at each time point （P0.05）.Conclusion Ischemic tolerance induced by repeated hyperbaric oxygen preconditioning may be related to the reduction of ubiquitin-proteasome accumulation.