Department of Emergency Medicine, West China Hospital, Sichuan University, 37 Guoxue Road, Chengdu, 610041, Sichuan, China.
Department of Cardiology, Chengdu Shangjin Jin Nanfu Hospital, Chengdu, China.
Neurocrit Care. 2018 Jun;28(3):379-387. doi: 10.1007/s12028-017-0486-4.
To determine the cerebral protective effects of mild hypothermia (MH) on cerebral microcirculation.
We established ischemia-reperfusion (I/R) injury and MH treatment models with rat brain microvascular endothelial cells (RBMECs) in vitro and examined the apoptotic changes. The cultured RBMECs were randomly divided into the control group, I/R group, and MH group, which was further divided into two subgroups: intra-ischemia hypothermia (IIH) and post-ischemia hypothermia (PIH). Cell morphological changes were assessed using fluorescence microscopy. Apoptotic rates were obtained by flow cytometry. Expressions of caspase-3, Bax, and Bcl-2 were analyzed by Western blot.
I/R injury in vitro induced apoptosis of RBMECs. The apoptotic rates in the control group, I/R group, and MH group were 0.13, 19.04, and 13.13%, respectively (P < 0.01). Compared with the I/R group, the MH group showed a significant decrease in the number of apoptotic cells, mainly in stage I apoptotic cells (P < 0.0083). The caspase-3 and Bax expressions were significantly enhanced (P < 0.05) in RBMECs after I/R injury, while substantial decreases in Bcl-2 expression were noted (P < 0.05). Following MH intervention, the increase in caspase-3 and Bax expression was suppressed (P < 0.05), while Bcl-2 expression significantly increased. The apoptotic rates or protein expressions between the two subgroups were not different significantly (P > 0.05).
These results indicate that MH could inhibit RBMEC apoptosis by preventing pro-apoptotic cells and early apoptotic cells from progressing to intermediate and advanced stages. This may be due to the effect of MH on I/R-induced apoptotic gene expression changes.
为了确定亚低温（MH）对脑微循环的脑保护作用。
我们建立了体外大鼠脑微血管内皮细胞（RBMEC）缺血再灌注（I / R）损伤和 MH 治疗模型，并观察了细胞凋亡的变化。将培养的 RBMEC 随机分为对照组、I / R 组和 MH 组，其中 MH 组又分为缺血期亚低温（IIH）和缺血后亚低温（PIH）亚组。荧光显微镜观察细胞形态变化。流式细胞术检测细胞凋亡率。Western blot 检测 caspase-3、Bax 和 Bcl-2 的表达。
体外 I / R 损伤诱导 RBMEC 凋亡。对照组、I / R 组和 MH 组的凋亡率分别为 0.13%、19.04%和 13.13%（P < 0.01）。与 I / R 组相比，MH 组凋亡细胞数明显减少，主要为 I 期凋亡细胞（P < 0.0083）。I / R 损伤后 RBMEC 中 caspase-3 和 Bax 的表达明显增强（P < 0.05），Bcl-2 的表达明显降低（P < 0.05）。MH 干预后，caspase-3 和 Bax 的表达增加受到抑制（P < 0.05），而 Bcl-2 的表达显著增加。两个亚组的凋亡率或蛋白表达无显著差异（P > 0.05）。
这些结果表明，MH 可通过阻止促凋亡细胞和早期凋亡细胞进展为中晚期，抑制 RBMEC 凋亡。这可能是由于 MH 对 I / R 诱导的凋亡基因表达变化的影响。
