HSP60和HSP70在严重烧伤大鼠胃黏膜的表达及对胃黏膜的保护作用

The Expressions of Heat Shock Proteins 60 and 70 and Their Protective Effect on the Gastric Mucosa of Burned Rats

目的观察严重烧伤大鼠胃黏膜热休克蛋白60和70(HSP60、HSP70)的表达变化及热休克预处理(HS)对严重烧伤大鼠胃黏膜的影响,探讨热休克预处理诱导HSP60、HSP70过量表达后对严重烧伤大鼠胃黏膜的保护作用。方法将Wistar大鼠随机分为2大组:①烧伤组(B组)40只大鼠烧伤后即制作急性胃黏膜损伤模型;另取8只大鼠不烧伤,作为正常对照组(伤前);②HS+烧伤组(HB组)40只大鼠于烧伤前20 h行HS,另取8只大鼠只行HS不烧伤,作为实验对照组(伤前)。各组于伤后3、6、12、24、48 h处死大鼠(B组、HB组每时相点8只大鼠),留取标本检测胃黏膜损伤指数(UI)、HSP60、HSP70的变化,并进行相关分析。结果大鼠严重烧伤后胃黏膜HSP60、HSP70表达迅速升高,随后开始下降,伤后24 h降至最低,此时胃黏膜损伤程度最严重(UI=12.74±1.92)。HB组大鼠较B组大鼠HSP60、HSP70表达均显著增强,胃黏膜损伤程度则明显减轻(P<0.05或P<0.01)。UI与HSP70呈显著负相关(r=-0.794,P<0.05),UI与HSP60无相关性(r=-0.625,P>0.05)。结论热休克预处理诱导HSP60、HSP70过量表达后可减轻大鼠烧伤后急性胃黏膜损害。烧伤大鼠胃黏膜HSP60、HSP70的表达增强可能是胃黏膜保护或修复的一种机制。

Objective To observe the changes of the expressions of heat shock proteinS（HSP） 60 and 70 in the gastric mucosa of burned rats and the effect of heat shock preconditioning（HS） on the gastric mucosa of burned rats in order to explore the protection of HSP 60 and 70. Methods Ninety-six wistar rats were divided randomly into two groups：（1）burn group （n=40, burned and then being made into the model of acute gastric mucosal lesion）and another 8 normal rats without burn were employed as blank control（preburn）; （2）HB group（n=40, HS before burn） and another 8 rats preconditioned with heat shock without burn were employed as experimental control. The rats in two groups were sacrificed and laparotomized before and 3,6,12,24 and 48 postburn hours（PBH） to observe the extent of gastric mucosal lesions （UI） and the specimen were taken to examine the changes in the expressions of HSP 60 and 70. Linear correlation analysis among UI and HPS 60 and 70 was carried out respectively. Results After burn injury, the expressions of HSP60 and HSP70 in gastric mucosa of rats increased rapidly and then fell gradually, with a valley at 24 hours of postburn, at which time point the extent of gastric mucosal lesions was greatest （UI=12.7±1.92）. The expressions of HSP60 and HSP70 were greatly increased in HB group compared with those in B group（P〈0.05 or P〈0.01）. Rats in B group were induced conspicu-ous gastric mucosal lesions, while UI in HB group was significantly lower. There was a negative correlation between UI and HSPT0（r=-0. 794,P〈0.05）. There was no correlation between UI and HSP60（r=-0. 625,P〉0.05）. Conclusion HS could amilioate acute gastric mucosa lesion in burned rats through inducing overexpression of HSP60 and 70. HSP60 and 70 might involve in the gastric mucoca protection in burned rats.