烫伤小鼠巨噬细胞内细胞因子变化与ERK信号的关系

The Relationship between Changes in Cytokines and the ERK Signal Pathway in Macrophages of Severely Scalded Mice

目的 :观察烫伤后腹腔巨噬细胞内肿瘤坏死因子 (TNF αmRNA)、活化蛋白 1(AP 1)变化及给予MEK1 2特异性阻断药PD980 5 9后TNF αmRNA、AP 1的改变 ,阐明丝裂原活化蛋白激酶 (MAPK)信号途径中的细胞外信息调节蛋白激酶 (ERK)信号通路是否调控烫伤后TNF αmRNA的生成。方法 :以 15 %体表面积Ⅲ度烫伤小鼠为模型 ,收集腹腔巨噬细胞 ,采用逆转录 多聚酶链式反应 (RT PCR)测TNF αmRNA的表达 ,电泳迁移率改变分析法 (EMSA)测AP 1的活性。结果 :烫伤后巨噬细胞内TNF αmRNA于烫伤后 2 ,12h表达较强 ,以后呈降低趋势。AP 1于烫伤后被激活。与单纯烫伤相比 ,PD980 5 9组的AP 1活性明显被抑制 ,而TNF αmRNA表达量无明显变化。结论 :严重烫伤后巨噬细胞内TNF αmRNA的过量表达反映了烫伤后巨噬细胞的功能紊乱 ,而MAPK信号途径于烫伤后被激活 ,其中TNF αmRNA的表达可能不受ERK信号途径调控。

Objective:To observe the dynamic changes in TNF α mRNA expression, AP 1(activator protein 1) activity of murine peritoneal macrophages (PMΦs) following burns as well as after the administration of the specific MEK 1/2 tlocker PD98059 in order to clarify whether the ERK (extracellular signal regulatory protein kinase) route along the MAPK signal pathway is involved in the regulation of the production of TNF α mRNA after scalds. Methods:An experimental model of 15% TBSA (total body surface area) full thickness vapor scalded mice was used and PMΦs were collected. AP 1 activity was measured by EMSA(electron microscope society of America) and TNF-α mRNA by RT PCR. Results:Expression of TNF-α mRNA by murine PMΦs increased to high levels at the second PBH (postburn hour) and twelfth PBH followed by gradual decline. AP 1 was activated following burns. In PD98059 treated mice, no evident changes in TNF α mRNA expression were noted while AP 1 activity was markedly inhibited, as compared with the respective parameters in mice with simple burns. Conclusion: Excessive expression of TNF α mRNA following severe scalds is a reflection of functional disorders of the macrophages. The MAPK signal pathway of macrophages is activated following scalds and the expression of TNF αmRNA is probably not regulated by the ERK signal pathway.