外周注射福尔马林诱导前扣带皮层中胶质细胞激活和细胞因子表达增高

为了观察外周注射福尔马林对大鼠前扣带皮层(ACC)中星形胶质细胞标记物胶质纤维酸性蛋白(GFAP)和S100B,小胶质细胞标记物CD14以及与胶质细胞密切相关的炎症前细胞因子白介素1β(IL-1β)、肿瘤坏死因子α(TNF-α)表达的影响,本研究结合行为学检测和RT-PCR方法,观察了大鼠单侧足底皮下注射福尔马林后的行为学变化,并检测了在不同时间点ACC中GFAP、S100B、CD14、IL-1β和TNF-α在基因水平的表达变化。结果显示:福尔马林急性疼痛刺激的大鼠出现典型的双时相自发性疼痛反应。ACC中GFAP和S100B mRNAs表达水平在刺激后30min、1h增高,2h恢复正常;CD14 mRNA表达水平在15min开始增高,1h达到高峰,6h恢复正常;IL-1β和TNF-αmRNAs表达水平在刺激后30min、1h、2h增高,6h恢复正常。上述结果表明,福尔马林外周急性伤害性刺激能够诱导ACC内短暂性的星形胶质细胞、小胶质细胞激活及IL-1β、TNF-α表达增高,提示激活的胶质细胞及表达上调的炎症前细胞因子可能参与伤害性信息的调制。

Glial activation and cytokines upregulation in the anterior cingnlate cortex induced by peripheral injection of formalin

To explore the effects of fomalin administrated into peripheral region on the expression of astroglial marker (glial fibrillary acidic protein,GFAP and S100B),microglial marker(CD14),and pro-inflammatory cytokines (IL-1β,TNF-α) in the the anterior cingulate cortex (ACC),the behavior observation and RT-PCR techniques were used to examine the behavioral changes following intraplantar administration of formalin in hindpaw of the rat and the expressional changes of GFAP,S100B,CD14,IL-1β,TNF-α mRNAs in the ACC at different time points.The results showed that a typical biphasic spontaneous pain response was observed in rats suffering acute pain. The expression of GFAP and S100B mRNAs increased at 30 min and 1 h,and returned to normal level at 2 h after formalin injection. The expression of CD14 mRNA began to increase at 15 min,peaked at 1 h and returned to normal level at 6 h. The expression of IL-1β and TNF-α mRNA increased at 30 min,1 h,2 h and returned to normal level at 6 h.The present results indicate that peripheral noxious stimulus induced transient activation of astrocytes,microglia,and enhanced the expression of IL-1β and TNF-α in the ACC,suggesting that glial cells and pro-inflammatory cytokines may be involved in the modulation of nociceptive information in rats.