CD200预处理对重症中暑大鼠炎症反应的影响

Pretreatment with CD200 alleviates systemic inflammation response in rats with severe heatstroke

目的:观察CD200预处理对重症中暑大鼠炎症反应的影响,探讨CD200参与重症中暑炎症反应的机制。方法:将40只雄性Wistar大鼠随机分为对照组(n=8)、重症中暑模型组(HS组,n=16)、CD200预处理组(CD200组,n=16)。HS组和CD200预处理组在热暴露前分别尾静脉注射生理盐水和CD200重组融合蛋白,制备经典中暑模型,对照组置于(22.0±1)℃室温下。分别于造模后60min时点检测肺组织CD200mRNA表达,检测血清高迁移率族蛋白B1(HMGB1)、肿瘤坏死因子α(TNF-α)和白介素6(IL-6)浓度。记录大鼠重症中暑形成时间、生存时间。结果:HS组和CD200预处理组CD200 mRNA表达均低于对照组(P<0.05);HS组和CD200预处理组血清中HMGB1、TNF-α、IL-6均明显高于对照组(P<0.05),HS组HMGB1、TNF-α、IL-6高于CD200预处理组(P<0.05);CD200预处理组相比HS组在重症中暑形成时间(P<0.05)和中位生存时间(P<0.05)均延长。结论:CD200的表达异常可能是重症中暑炎症反应的分子机制之一,CD200预处理可以减轻重症中暑大鼠炎症反应,改善热应激状态下大鼠的预后。

Objective：To observe the effect of CD200 pretreatment on systemic inflammatory response in rats induced by severe heat-stroke. Method： Forty rats were randomly assigned into normalcontrol group （n= 8）, heat stroke model group （HS group,n= 16）, and CD200 pretreatment group （CD200 group, n=16）. Rats in the HS group and CD200 group were placed in an artificial climate chamber to induce HS, while rats of control group were kept at room temperature （22±1℃）. For CD200 group, 100 /11 CD200 （1 000μg/ml） recombinant fusion protein was intravenously infused before heat-stress, for HS group, 100 ul saline was intravenously infused before heat- stress. The HS group and CD200 group rats were sacrificed in batches at 0,12 h after successful modeling. The lev- els of high mobility group protein B1 （HMGB1）,tumor necrosis factor α （TNF-α）,interleukin-6 （IL-6） were de- termined. The expression of CD200 mRNA were also assayed. The time-point of heatstroke onset and survival tim- ewere recorded. Result：The expression of CD200 mRNA were significant decrease after heat treatment in HS group and CD200 group compared withcontrol group （P〈0.05）. ELISA results showed, compared with control group, both the HMGB1, IL-6,TNF-α releases were increased after heat treatment in HS group and CD200 group （P〈0. 05） ,and them were also increased in HS group compared with CD200 group （P〈0.05）. The time-point of heat- stroke onset and survival timewere prolonged in CD200 group compared withHS group （P〈0.05）. Conclusion：Ex- pression rate of CD200 decreased significantly in rats with severe heatstroke,in the meantime, the serum levels of HMGB1,TNF-α, IL-6 increased significantly. However, in rats pretreatmentwithCD200, the serum levels of HMGB1,TNF-α,IL-6 decrease. The time-point of heatstroke onset and survival timewere prolonged in pretreat- ment with CD200.