大鼠压力性损伤皮肤皮下组织中IL-6受体表达及其意义

Expression and significance of interleukin-6(IL-6)receptor in subcutaneou tissue of rats with stress injury

目的观察大鼠压力性损伤组织中膜结合型IL-6受体(mIL-6R)和可溶型IL-6受体(sIL-6R)及受其调控的细胞因子表达水平,探讨IL-6受体对压力性损伤发生发展的影响及机制。方法将60只雄性SD大鼠随机分为正常对照组(n=20)、压力性损伤模型组(n=20)、sgp130Fc(特异性IL-6反式信号通路阻断剂)预处理组(n=20)。正常对照组不做任何处理;压力性损伤模型组在麻醉下于股薄肌处建立压力性损伤模型;sgp130Fc预处理组大鼠在麻醉前30 min给予sgp130Fc 250 ng腹腔内注射,随后在麻醉下采取与压力性损伤模型组相同的方法建立压力性损伤模型。大鼠建立压力性损伤模型成功后分别取股薄肌处组织及血液,运用ELISA法检测血液中IL-6、sIL-6R表达水平,运用免疫组化法检测组织中mIL-6R、细胞间黏附分子-1(ICAM-1)、血管内皮生长因子(VEGF)及凋亡因子(Bcl-2、Bax、Caspase-3)的表达。运用Tunel法观察组织中细胞凋亡水平。结果与正常对照组大鼠相比,压力性损伤模型组大鼠血液中IL-6、sIL-6R及组织中ICAM-1、Bax、Caspase-3表达明显增加(P<0.05),而组织中mIL-6R、VEGF表达减少(P<0.05)。sgp130Fc预处理组大鼠组织中mIL-6R、VEGF、Bcl-2的表达与压力性损伤模型组大鼠相比无明显差异(P>0.05),ICAM-1、Bax、Caspase-3的表达及细胞凋亡指数明显低于压力性损伤模型组大鼠(P<0.05)。结论压力性损伤大鼠组织中mIL-6R表达减少,血液中sIL-6R水平异常升高。异常升高的sIL-6R可上调炎症因子和凋亡因子表达,促使压力性损伤发生。

Objective To investigate the role of the interleukin-6(IL-6)receptor in occurrence of pressure injury.To observe the expression of membrane-bound interleukin-6 receptor(mIL-6R)and soluble interleukin-6 receptor(sIL-6R)as well as the inflammatory cytokines.Methods 60 male Sprague-Dawley rats were randomly assigned to control group(n=20),the pressure injury model group(n=20)and sgp130Fc treatment group(a specific IL-6 trans-signaling pathway blocker,n=20).The normal control group did not receive any treatment,whereas the latter 2 groups were established the pressure injury model on gracilis muscle on both hind limbs using a way of cycle compression of ischemia-reperfusion magnet.The sgp130Fc group received intraperitoneal injection of 250 ng of sgp130Fc 30 minutes before the surgery.The tissue and blood samples were taken when the pressure injury modelling process was established.The expression levels of IL-6 and sIL-6R in the blood were determined by ELISA assay.The expression levels of mIL-6R,intercellular adhesion molecule-1(ICAM-1),vascular endothelial growth factor(VEGF)and apoptosis-related proteins(Bcl-2,Bax,Caspase-3)were detected by immunohistochemistry.Tunel method was used to observe the level of apoptosis in the tissues.Results Compared with the normal control group,the pressure injury model group had significant increases in the expressions of IL-6 and sIL-6R in blood and ICAM-1,Bax and Caspase-3 in tissue(P<0.05),while significant reductions in the expressions of mIL-6R and VEGF in tissue(P<0.05).There were no significant differences in the expression levels of mIL-6R,VEGF and Bcl-2 in the tissues of the rats pretreated with sgp130Fc compared with those of the rats in the pressure injury model group(P>0.05).The expression levels of ICAM-1,Bax and Caspase-3 and the apoptosis index of the sgp130Fc pre-treatment group rats were significantly lower than those in the pressure injury model group(P<0.05).Conclusion The reduction of expression of mIL-6R and the abnormal increment expression of sIL-6R were observed in the tissue and blood of pressure injury rats.Abnormal elevation of sIL-6R can upregulate the expression of inflammatory and apoptotic factors and promote the occurrence of pressure injury.