地塞米松抑制谷氨酸诱导的大鼠小胶质细胞活化

Dexamethason suppresses the activation of rat microglia induced by glutamic acid

目的探讨地塞米松(DEX)对谷氨酸(GLU)诱导的大鼠小胶质细胞活化的影响。方法分离纯化并体外培养SD幼鼠脊髓小胶质细胞,并通过免疫荧光技术鉴定小胶质细胞并检测其纯度,按照随机数字表法将细胞分为5组:Dulbecco磷酸盐缓冲液处理组(DPBS组)、GLU处理组、DEX预处理后再用GLU处理组、DEX与GLU同时处理组、GLU刺激再用DEX处理组。通过免疫荧光技术检测糖皮质激素受体(GR)与小胶质细胞活化标志蛋白CD11b/c的表达。结果与DPBS对照组比较,GLU处理组CD11b/c表达增强,且细胞突起长度缩短,形态变圆;而与GLU组比较,DEX与GLU同时处理组和GLU刺激后DEX再处理组CD11b/c表达降低,DEX预处理后再用GLU处理组无差异。结论 DEX对GLU诱导大鼠小胶质细胞的活化产生抑制作用,而预处理无此作用。

Objective To investigate the effect of dexamethasone （DEX） on the microglia activation induced by glutamic acid （GLU） in rats. Methods We isolated and cultured the microglia from the spinal cord of SD infant rats in vitro. The cell purity was tested by immunofluorescence technique. The cells were then randomly divided into 5 groups： Dulbecco＇s phosphate buffered saline treatment （ DPBS group） ; GLU treatment （GLU group） ; DEX pretreatment and then GLU stimulation; simultaneous treatment of DEX and GLU; GLU stimulation followed by DEX treatment. Finally, immunofluorescence technique was used to investigate the expressions of glucocorticoid receptor （GR） and CD11b/c protein. Results Compared with the DPBS group, GLU group presented the increased expression of CD11b/c protein, the shorten length of cell processes as well as cell shape turning round. Furthermore, compared with the GLU group, the CD11b/c protein expression significantly decreased in the group treated simultaneously with DEX and GLU and the group treated with DEX after GLU stimulation. However, the expression was not different between the GLU group and the group treated with DEX and then stimulated by GLU. Conclusion DEX could inhibit microglia activation induced by GLU, while DEX pretreatment have no such an effect on microglia.