p38MAPK对轻度热应激大鼠脾脏巨噬细胞免疫功能的影响

目的: 探讨p38MAPK在Bip蛋白介导的体外轻度热应激大鼠巨噬细胞功能改变中的信号作用.方法: p38MAPK抑制剂预处理大鼠脾脏巨噬细胞,将细胞置于41℃恒温箱中,使细胞轻度热应激,1 h后恢复到37℃(抑制组),以未应激(对照组)和41℃热应激1 h后60 min巨噬细胞(应激组)为对照,分别检测3组巨噬细胞吞噬、杀伤、趋化功能,同时检测p38MAPK蛋白和Bip蛋白的表达.结果: p38MAPK抑制剂预处理大鼠脾脏巨噬细胞,与应激组比较,轻度热应激后巨噬细胞吞噬、趋化和杀伤活性明显降低(0.17±0.01 vs 0.74±0.03,33.32±3.55 vs 82.07±5.17,24.20%±2.39% vs 60.80%±4.02%,均P<0.01);应激组p38MAPK蛋白表达明显上调,p38MAPK抑制剂预处理后,抑制组p38 MAPK蛋白表达受到抑制,与应激组比较差异有显著性(p38/β-actin: 2.863±0.794 vs 4.752±1.386,P<0.01);Bip蛋白的表达(Bip/β-act in)也因p38MAPK抑制剂预处理而由应激组的1.270±0.535降至抑制组的1.028±1.061( P<0.05).结论: p38MAPK抑制剂可显著抑制轻度热应激大鼠巨噬细胞吞噬、趋化和杀伤功能以及p38MAPK和Bip蛋白的表达.

Effect of p38MAPK on immunofunction of spleen macrophages from heat stressed rats

AIM: To investigate the role of p38MAPK in Bip protein-mediated functional changes of mild heat stressed rat splenic macrophages in vitro. METHODS: Rat splenic macrophages were pretreated with p38MAPK inhibitor and placed into 41℃ incubator for mild heat stress. One hour later,temperature was restored to 37℃ in inhibition group. Non stressed rat spleen macrophages were assigned to the control group,and macrophages which was heat stressed at 41 ℃ for 1 h (stress group) were used as controls,too. Three groups were detected for macrophage phagocytosis,cytotoxicity and chemotaxis. At the same time p38MAPK protein and Bip protein expressions were detected. RESULTS: p38MAPK inhibitor pretreated rat splenic macrophages,when compared with the stress group,their phagocytosis,cytotoxicity and chemotaxis were significantly lowered after mild heat stress (0.17 ± 0.01 vs 0.74 ± 0.03,33.32 ± 3.55vs 82.07 ± 5.17,24.20% ± 2.39% vs 60.80% ± 4.02%,all P < 0.01). In stress group p38MAPK protein expressions were significantly increased;compared with the stress group,p38MAPK protein expressions were significantly inhibited after p38MAPK inhibitor pretreatment in inhibition group (p38/β-actin: 2.863 ± 0.794 vs 4.752 ± 1.386,P < 0.01). p38MAPK inhibitor pretreatment also caused changes in Bip protein expressions (Bip/ β-actin) in the stress group from 1.2702 ± 0.5345dropped to 1.0281 ± 1.0614 in inhibition group (P < 0.05).CONCLUSION: p38 inhibitors can significantly inhibit mild heat stressed rat splenic macrophage phagocytosis,cytotoxicity and chemotaxis,which inhibit p38MAPK and Bip protein expressions.