不同程度内质网应激对巨噬细胞自噬的影响

Effects of the Different Degree of the Endoplasmic Reticulum Stress on Macrophage's Autophagy

目的:采用ox-LDL诱导巨噬细胞泡沫化模型,通过不同剂量衣霉素诱导巨噬细胞不同程度内质网应激,观察对其自噬的影响。方法:不同剂量衣霉素作用于小鼠巨噬细胞系RAW264.7,通过TUNEL染色检测其凋亡率,Western blot检测内质网应激蛋白GRP78,以及自噬标志蛋白P62的表达水平。结果:与ox-LDL组和大剂量衣霉素组相比,小剂量衣霉素组可以显著减少巨噬细胞的凋亡(P<0.01);与ox-LDL组相比,小剂量衣霉素组上调内质网应激蛋白GRP78表达的同时,自噬标志蛋白P62适度下降(P<0.01);大剂量衣霉素组更为显著地上调了内质网应激蛋白GRP78表达,但同时自噬标志蛋白P62也显著增加(P<0.01)。结论:小剂量衣霉素引起一定程度的内质网应激,可以激活适度的自噬,从而减少巨噬细胞的凋亡,可能有助于降低动脉粥样硬化的程度。

Objective： By using ox-LDL-indueed macrophage foam cell model, we used different doses of tunicamycin to induce different degree of the endoplasmic reticulum stress, to observe the effects of it on autophagy. Methods： Different doses of tunieamycin were added to maerophage RAW264.7. The apoptosis rate was detected with TUNEL method. And the expression level of the endoplasmic reticulum stress marker protein GRP78 and autophagy marker protein P62 were detected by western blotting. Results： Compared with the ox-LDL group and the high-dose ttmicamycin group, low-dose of tunieamycin significantly reduced the apoptosis of macrophage （P〈0.01）; compared with ox-LDL group, the endoplasmic reticulum stress marker protein GRP78 expression was remarkable increased in low-dose tunicamycin group; meanwhile, the autophagy marker protein P62 moderately decreased （P〈0.01）; in the high-dose ttmicamycin group, there was more significant increase in the endoplasmic reticulurn stress marker protein GRP78 expression, however the autophagy marker protein P62 also increased notably （P〈0.01）. Conclusion： Low-dose of tunicamycin caused a certain degree of endoplasmic reticulum stress, which activated moderate autophagy, decreasing macrophage apoptosis. It may help to reduce the extent of the atherosclerosis.