血管内皮祖细胞-血管再生在缺血再灌注损伤中的作用探讨

The potential effects of EPCs-angiogenesis on ischemia-reperfusion injury

目的探讨血管内皮祖细胞(EPCs)-血管再生途径在血红素结合蛋白(HPX)改善大鼠脑缺血再灌注(I/R)后认知功能障碍中的作用。方法 SD雄性大鼠依处理方式不同分为假手术(Sham)组31只、局灶性I/R(MCAO,0.9%生理盐水10μL)组30只、MCAO+叠氮钠(Vehicle,0.1%Vehicle 10μL)组30只、MCAO+HPX(1.86 g/L的HPX10μL)组30只。采用改良的神经功能缺损评分(m NSS)评价大鼠I/R后神经功能缺损程度,Morris水迷宫(MWM)实验检测大鼠I/R后的学习记忆能力改变;流式细胞技术(FCM)结合CD34/CD133双抗体标记技术检测大鼠I/R后外周血中EPCs数量变化;免疫组织化学技术结合CD31/v WF免疫荧光显色技术检测大鼠I/R后缺血半暗带皮质区新生血管数量。结果与Sham组相比,MCAO组大鼠I/R后m NSS升高,逃避潜伏期延长,目标象限时间百分比减少,外周血中EPCs数量增加,缺血半暗带皮质区血管数量增加(均P<0.05);MCAO+Vehicle组大鼠与MCAO组相比,I/R后m NSS、逃避潜伏期、目标象限时间百分比、外周血中EPCs数量和缺血半暗带皮质区血管数量均无明显变化(均P>0.05);MCAO+HPX组大鼠与MCAO组、MCAO+Vehicle组相比,I/R后m NSS显著降低,逃避潜伏期显著缩短,在目标象限时间百分比明显增加,外周血中EPCs计数显著增加,缺血半暗带皮质区血管数量明显增加(均P<0.05)。结论 EPCs-血管再生机制在HPX改善大鼠局灶性I/R后认知功能障碍中发挥积极的作用。

Objective To explore the potential effects of endothelial progenitor cells (EPCs)-angiogenesis on mechanism of alleviating cognitive dysfunction in rats subjected to cerebral ischemia-reperfusion (I/R) injury. Methods A total of 121 male Sprague–Dawley (SD) rats were randomly divided into four groups:Sham group (n=31), focal I/R(MCAO, 0.9%saline 10μL, n=30) group, MCAO+Vehicle (sodium azide, 0.1%Vehicle 10μL, n=30) group and MCAO+HPX (1.86 g/L HPX 10μL, n=30) group. The modified neurological severity scores (mNSS) was carried out to determine neurological function deficit after I/R. Morris water maze (MWM) was carried out to assess learning and memory abilities after I/R. The circulating EPCs after I/R were counted by flowcytometry (FCM) combined with double-immunofluorescence staining of CD34 and CD133. Angiogenesis in rat penumbra cortex after I/R was assessed by immunohistochemical technique combined with immunofluorescent chromogenic detection of CD31 and vWF. Results Compared with sham group, the mNSS scores, the escape latency and the circulating EPCs count were increased after I/R, the time percentage spent in target quadrant was reduced, and the new vessel density in penumbra cortex was increased after I/R in MCAO group (P < 0.05 respectively). There were no significant differences in mNSS score, the escape latency, the time percentage spent in target quadrant, the circulating EPCs count and the new vessel density in penumbra cortex between MCAO group and MCAO+Vehicle group ( P>0.05). The mNSS score and the escape latency were significantly decreased, the circulating EPCs count and new vessel density in penumbra cortex were significantly increased after I/R in MCAO+HPX group compared with those of MCAO+Vehicle and MCAO group (P<0.05). Conclusion EPCs-angiogenesis signaling plays positive effects on HPX alleviating cognitive dysfunction in rats subjected to focal cerebral ischemia reperfusion injury.