CD200在重症中暑大鼠中的表达及其与炎症因子关系

Relationship between expression of CD200 and inflammation mediators in rats with severe heatstroke

目的观察CD200在重症中暑大鼠中的表达与变化规律,及其与炎症因子分泌的关系,初步探讨CD200参与重症中暑炎症反应的机制。方法将雄性Wistar大鼠32只,随机分为对照组(n=8)、重症中暑组(HS,n=24)。重症中暑组置于人工气候舱内,温度(40±2)℃,湿度(65±5)%,热打击制备经典中暑模型,对照组置于(22.0±1)℃室温下。分别于造模后0、6、12 h时点采血并处死大鼠,抽血用酶联免疫法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,采用RT-PCR法检测肺组织CD200 m RNA表达。结果重症中暑组各时点CD200m RNA表达均低于对照组(P<0.05),热打击后CD200 m RNA表达逐渐降低,且呈时间依赖性递减(P<0.05);重症中暑组血清中HMGB1、TNF-α、IL-6均明显高于对照组(P<0.05);热打击后HMGB1、TNF-α、IL-6分泌逐渐上调,且呈时间依赖性升高(P<0.05);CD200 m RNA表达降低与HMGB1(r=-0.635,P<0.05),TNF-α(r=-0.701,P<0.05),IL-6(r=-0.786,P<0.05)浓度升高呈显著负相关性。结论重症中暑时,CD200表达减少并随着时间进一步降低,促炎细胞因子HMGB1、TNF-α和IL-6分泌增多并随时间逐渐升高,CD200表达减少与HMGB1、TNF-α和IL-6分泌增多呈负相关。CD200的表达异常可能是重症中暑炎症反应的分子机制之一。

Objective To investigate the relationship and mechanism between the expression of CD200 and the serum levels of inflammation mediators in rats with severe heatstroke（HS）. Methods Thirty-two male Wistar rats were randomly divided into a normal control group（n=8）and a heatstroke group（HS group,n=24）. The rats of the HS group were placed in an artificial climate chamber [temperature（40±2）℃,humidity（65±5）%] to induce HS,while the rats of the control group were kept at room temperature（22±1）℃. The HS group rats were sacrificed in batches at 0,6 and 12 h after successful modeling. The levels of high mobility group protein B1（HMGB1）,tumor necrosis factor α（TNF-α）,and interleukin-6（IL-6）were determined. The expression of CD200 mRNA was also assayed by RT-PCR. Results The expression of CD200 mRNA was significantly decreased after the heat treatment（P〈0.05）,and it showed a gradual decrement trend performance over time（P〈0.05）. Compared with the control group,HMGB1,IL-6,and TNF-α were increased after the heat treatment（P〈0.05）,and this effect was enhanced with the prolongation of exposure time（P〈0.05）. There was a negative correlation between the expression of CD200 mRNA and the serum levels of HMGB1（r =-0.635,P〈0.05）,TNF-α（r =-0.701,P〈0.05）,and IL-6（r =-0.786,P〈0.05）. Conclusion The expression rate of CD200 decreases significantly in rats with severe heatstroke,in the meantime,the serum levels of HMGB1,TNF-α,and IL-6 increase significantly. There is a negative correlation between the CD200 decrease and HMGB1,TNF-α,and IL-6 increases. These results indicate that CD200 might participate in the pathogenesis of inflammation in severe heatstroke.