急性冷热应激对大鼠脊髓和脊神经节ERK信号转导的影响  

Effect of acute cold or heat stress on ERK activation in the spinal cord and ganglia of rats

作　　者：王进堂[1] 尹岭[1] 田淑君[1] 张笑明[1] 

机构地区：[1]中国人民解放军总医院神经信息中心,北京100853

出　　处：《神经解剖学杂志》2009年第2期163-169,共7页Chinese Journal of Neuroanatomy

基　　金：973国际合作课题(No.2004CB720300);国家自然科学基金(No.30171135)资助项目

摘　　要：ERK是细胞内MAPK信号转导系统的重要蛋白激酶,参与多种刺激的应激反应。本实验建立冷热应激模型,应用免疫组织化学和Western blot方法,研究冷热应激刺激对大鼠脊髓和脊神经节ERK的激活作用。结果显示:(1)正常脊髓非磷酸化ERK1(pan-ERK1)阳性细胞分布于RexedIII-X层,而I-II层没有免疫反应,胞浆着色,没有核膜断裂;磷酸化ERK1/2(p-ERK1/2)阳性细胞见于灰质Rexed各层(I-X),散在分布。免疫产物位于胞浆核周区,少见于细胞核,核膜有断裂。脊神经节p-ERK1/2免疫反应见于大、中、小型神经元,定位于细胞核;没有pan-ERK1免疫反应。(2)20min热应激后,RexedII层p-ERK1/2阳性细胞数明显增多,核周着色区增大,核膜常有断裂,脊神经节阳性细胞数没有明显变化;10min热应激和体温(38℃)应激后,脊髓和脊神经节阳性细胞数和核着色没有显著变化。(3)20min冷应激后,脊髓II层p-ERK1/2阳性细胞数轻度减少,核周着色区变窄,核膜有断裂,脊神经节阳性细胞数没有变化;10min冷应激后阳性细胞数没有明显变化。(4)Western blot显示,热应激和冷应激分别提高和降低了胸段脊髓p-ERK1/2的蛋白表达水平。本研究证实,ERK存在于脊髓灰质各层和脊神经节各型神经元,热应激提高了ERK激活水平而冷应激则相反,提示MAPK信号转导激活具有应激类型和应激强度的依赖性,参与了感觉神经元的功能调节。ERK （ Extracellular signal-regulated protein kinases） is an important protein kinase of MAPK （ Mitogen-activated protein kinase） signal transduetion, which is involved in stress responses of multiple environmental stimuli. To investigate the distribution and the changed activation of ERK in the spinal cord and spinal ganglia of rats exposed to acute cold or heat stress, the stress models were established and the immunohistochemistry and Western blotting analysis were used. Results showed that ： （ 1 ） In the normal spinal cord, pan- ERK immunoreaction was localized in Rexed Ⅲ-X, without staining in Rexed Ⅰ-Ⅱ; the phospho-ERK1/2 （p-ERK1/2） positive cells were mainly and evenly scattered in all Rexed layers（ Ⅰ-X ）, and occasionally seen in the white matter. The brown products were located in cytoplasm, especially around nucleus, and rarely in nucleus. The broken nucleus membranes were seen occasionally. In the spinal ganglia, p- ERK1/2 immunoreaction was distributed in the large-, medium-, and small-sized neurons with cell nuclei staining. （2） Acute heat stress （20 min） significantly induced the increased positive cells in the thoracic Rexed Ⅱ layers, but in Rexed Ⅲ-X layers no evident alteration was found in the number of positive cells, and the broken nuclear membranes often seen ; 10 min of heal stress did not greatly alter the positive cell number and nucleus staining. （3） Acute cold stress （20 rain） reduced the positive cells in the thoracic Rexed II layer, with perinucleus staining thinner and the broken nucleus membrane rarely seen; 10 min of cold stress did not display the reduced positive cells. In the spinal ganglia, there was no significant change for either cold or heat stress. （4） Western blot analysis showed that heat stress upregulated the activated ERK1/2 in the thoracic spinal cord, with cold stress downregulating it. The results indicate that cold and heat stresses may alter ERK1/2 activation in the spinal cord, with heat stress enhancing ERK1/2

关 键 词：冷应激 热应激 丝裂原激活蛋白激酶(MAPK) 细胞外信号调节蛋白激酶(ERK) 大鼠 

分 类 号：R363[医药卫生—病理学]