轻度热应激大鼠脾脏巨噬细胞BiP蛋白的表达与意义

目的： 探讨轻度热应激脾脏巨噬细胞免疫球蛋白结合蛋白(BiP/GRP78)的表达及其对细胞功能改变的影响。方法: 原代培养脾脏巨噬细胞，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 ℃，分别检测应激后0 min、30 min、60 min、120 min、180 min巨噬细胞BiP mRNA、BiP蛋白的表达；同时段分别检测巨噬细胞吞噬功能、杀伤活性和趋化作用。结果: （1）轻度热应激后，脾脏巨噬细胞BiP mRNA的表达明显增加，30 min后到达高峰，60 min、120 min时仍高于对照组，180 min后恢复至正常水平。BiP蛋白的表达在60 min后到达高峰，120 min、180 min时仍高于对照组。（2）轻度热应激后，脾脏巨噬细胞的吞噬功能、杀伤活性和趋化作用均明显增强，且与BiP mRNA、BiP蛋白表达的改变基本同步。结论: 轻度热应激脾脏巨噬细胞BiP mRNA、BiP蛋白的表达与巨噬细胞功能发生同步改变，提示BiP蛋白表达上调可能与轻度热应激脾脏巨噬细胞功能增强密切相关。

Expression of BiP in rat splenic macrophages with mild heat stress

AIM: To investigate the role of mild heat stress towards the immunological function of splenic macrophages and significance of BiP protein expression. METHODS: Primary cultured splenic macrophages were prepared and placed in 41 ℃ thermostat for thermal stress and restored to 37 ℃ after an hour. Heat stressed macrophages were separated into groups at time points of 0 min, 30 min, 60 min, 120 min and 180 min, and their BiP mRNA and BiP protein expressions were detected. At the same time, the phagocytic function, cytotoxicity and chemotaxis of the macrophages were detected. RESULTS: After heat stress, the expressions of BiP mRNA and BiP protein in splenic macrophages remarkably increased, and reached to peak after 30-60 min, still remained higher than control group after 120 min and restored to normal level after 180 min. At the same time, mild heat stress enhanced the phagocytotic, cytotoxicity and chemotactic activities of splenic macrophages, and reached to peak after 60 min then gradually decreased. CONCLUSION: The expression of BiP protein is enhanced after mild heat stress, synchronous changes happen both in BiP protein expression and cellular function. There is close relation between BiP protein expression and increased functions of splenic macrophages induced by mild heat stress.