N-甲基-D-天冬氨酸受体/MAPK/环磷腺苷效应元件结合蛋白通路在前扣带皮层介导痛相关情绪

N-methyl-D-aspartic acid receptor/MAPK/cAMP-response element binding protein pathway mediating pain-related aversion in anterior cingulate cortex

目的探讨N-甲基-D-天冬氨酸(NMDA)受体/MAPK/环磷腺苷效应元件结合蛋白(CREB)通路参与前扣带皮层介导痛相关情绪的机制。方法选取健康SD大鼠共42只,随机分为空白对照组(Ctrl)、脚掌注射生理盐水(NS)组、脚掌注射完全弗氏佐剂(CFA)模型组(CFA)、脚掌注射CFA及前扣带皮层吻侧部(rACC)中注射NS组(CFA+NS)、脚掌注射NS及rACC中注射NS组(NS+NS)、脚掌注射CFA及rACC内注射NMDA受体拮抗剂(APⅤ)组(CFA+APⅤ)、脚掌注射NS及rACC内注射APⅤ组(NS+APⅤ),每组n=6只。分析大鼠回避分数及观察大鼠热缩足潜伏期(PWL),采用免疫组织化学染色检测脑rACC区NMDA受体表达;免疫荧光染色检测脑rACC区NMDA受体、磷酸化ERK(p-ERK)、磷酸化CREB(p-CREB)表达;尼氏染色观察脑rACC区尼氏小体数量;Western blotting检测rACC区NMDA受体、MAPK、CREB、ERK、p-ERK、p-CREB、突触小体相关蛋白25的相互作用蛋白30(SIP30)蛋白表达;Real-time PCR检测脑rACC区NMDA受体、MAPK、CREB、ERK的mRNA表达。结果与Ctrl组比较,CFA组大鼠回避分数及PWL明显降低,NMDA受体、MAPK、CREB表达明显增加(P<0.05);与CFA+NS组比较,CFA+APⅤ、NS+APⅤ组尼氏小体数量明显升高,NS+NS、NS+APⅤ组NMDA受体、MAPK、CREB、p-ERK、p-CREB表达明显降低(P<0.05)。结论rACC中的NMDA受体/MAPK/CREB信号通路参与了痛相关情绪,抑制NMDA可减轻痛相关负情绪。

Objective To explore the mechanism of N-methyl-D-aspartic acid(NMDA)receptor/MAPK/cAMPresponse element binding protein(CREB)pathway involved in pain-related aversion mediated by anterior cingulate cortex.Methods A total of 42 healthy SD rats were randomly divided into control group(Ctrl),normal saline(NS)injection group(NS),complete freund adjuvant(CFA)model group(CFA),injected CFA into the soles of the foot and injected NS into rostral part of anterior cingulate cortex(rACC)group(CFA+NS),injected NS into the soles of the foot and injected NS into rACC group(NS+NS),injected CFA into the soles of the foot and injected NMDA receptor antagonist(APⅤ)into rACC group(CFA+APⅤ),injected NS into the soles of the foot and injected APⅤinto rACC group(NS+APⅤ)with 6 rats in each group.Rats avoidance score was analysised and rat thermal foot contraction latency(PWL)ws alserved,the expression of NMDA receptor in rACC region was detected by immunohistochemical staining,the expression of NMDA receptor,phosphorylated ERK(p-ERK)and phosphorylated CREB(p-CREB)in rACC region was detected by immunofluorescent staining,the number of Nissl bodies in rACC region was observed by Nissl staining,and the expression of NMDA receptor,MAPK,CREB,ERK,p-ERK,p-CREB,synaptosomal-associated protein 25 interaction protein 30(SIP30)protein in rACC region was detected by Western blotting,and Real-time PCR was used to detect the mRNA expression of NMDA receptor,MAPK,CREB and ERK in the rACC region.Results Compared with the Ctrl group,the avoidance score and PWL decreased significantly and the expression of NMDA receptor,MAPK and CREB increased significantly in the CFA group(P<0.05).Compared with the CFA+NS group,the number of Nissl bodies in CFA+APⅤand NS+APⅤgroups increased significantly,while the expression of NMDA receptor,MAPK,CREB,p-ERK and p-CREB decreased significantly in NS+NS and NS+APⅤgroups(P<0.05).Conclusion NMDA receptor-MAPK-CREB signal pathway in rACC is involved in painrelated aversion,and inhibition of NMDA can reduce pain-related negative aversion.