孕酮对大鼠脑缺血再灌注损伤后TASK3蛋白表达的影响

Effects of progesterone on TASK3 expression in rats after cerebral ischemia and reperfusion injury

目的观察孕酮对大脑中动脉栓塞(MCAO)大鼠脑组织TASK3蛋白表达的影响,探讨孕酮对脑缺血再灌注损伤大鼠的脑保护作用及机制。方法雄性SD大鼠随机分为正常对照组、假手术组、缺血再灌注组(I/R组)和孕酮+I/R组,后3组按缺血再灌注后不同时间随机分为0 h、6 h、12 h、24 h、48 h、72 h、96 h和120 h 8个亚组。线栓法建立大鼠右侧MCAO模型,缺血2 h再灌注24 h进行脑损伤评估,检测各组大鼠死亡率、神经功能缺陷评分以及2,3,5-氯化三苯基四氮唑(TTC)染色测定脑梗死体积;采用免疫印迹法检测各组大鼠脑组织缺血2 h再灌注后不同时间点TASK3蛋白的表达。结果孕酮+I/R组大鼠死亡率(18.18%)明显低于I/R组(40.66%),该组动物脑梗死体积(21.85%±3.53%)也显著低于I/R组(37.21%±3.50%)(P<0.01),且该组神经功能缺陷评分(2.00±0.74)显著低于I/R组(2.67±0.49)(P<0.05)。与正常对照组相比,假手术组各时间点脑组织TASK3蛋白的表达无明显变化,而I/R组各时间点脑组织TASK3蛋白的表达均显著降低(P<0.05);与I/R组相比,孕酮+I/R组各时间点脑组织TASK3蛋白的表达显著升高(P<0.05)。结论孕酮对脑缺血再灌注损伤的大鼠具有脑保护作用,其机制可能与上调TASK3通道蛋白的表达有关。

Objective To investigate the effect of progesterone （PROG） on the expression of Two-pore domain K channel 3 （TASK3） after cerebral ischemia-reperfusion injury in rats. Methods Male Sprague-Dawley rats were divided into four groups randomly ： normal control group, sham-operated group, ischemia-reperfusion group （ I/R group） and PROG ＋ I/R group. Sham-operated group,I/R group and PROG ＋ I/R group were divided into 0 h,6 h,12 h,24 h,48 h,72 h,96 h and 120 h eight subtypes according to different reperfusion time. The model of MCAO was established by the line-embolism method. The mortality rate, the nervous functional defect degree and the volumes of cerebral infarction were evaluated when rats were suffered 2 h/24 h ischemia-reperfusion stress. The expression of TASK3 protein in right brain was measured by Western blotting assay at reperfusion time of 0 h,6 h,12 h,24 h,48 h,72 h,96 h and 120 h after 2 h ischemia. Results The mortality rate in PROG ＋ I/R rats （ 18.18% ） were obviously lower than that of I/R group（40.66% ）. The nervous defect scores in PROG ＋ I/R rats （2.00 ± 0.74） were significant lower than that of I/R group （ 2.67 ± 0.49 ） （ P 〈 0.05 ）. The volumes of cerebral infarction in PROG ＋ I/R group （21.85% ± 3.53% ） were significant lower than that of I/R group （37.21% ± 3.50% ） （ P 〈 0.01 ）. No significant difference of the protein expression of TASK3 in brain tissues at all time points between normal control group and sham-operated group was detected. However, the protein expression of TASK3 in brain tissue at all time points significant decreased in I/R group as compared with normal control group （ P 〈 0.05 ）. Compared with I/R group, the protein expression of TASK3 in brain tissue at all time points dramatically increased in PROG ＋ I/R group （ P 〈 0.05 ）. Conclusion Progesterone exerts the neuroprotective effect on focal cerebral ischemia/ reperfusion injury in rats,the protective mechanism might be associated with up-regulating the expression of TASK3 protein in brain.