氧化低密度脂蛋白联合流感病毒加重内质网应激致巨噬细胞凋亡

Oxidized low density lipoprotein combined with influenza virus induced macrophages apoptosis by aggravating endoplasmic reticulum stress

目的 探讨氧化低密度脂蛋白模拟的高脂环境对流感病毒感染巨噬细胞的影响并阐明其内在机制.方法 分别运用流式细胞术,MTT法检测有无氧化低密度脂蛋白预处理,不同剂量流感病毒感染THP-1巨噬细胞8h、24 h、48 h后,细胞存活率和凋亡率的变化.RT-PCR、Western blot检测内质网应激相关分子GRP78、GADD153的mRNA和蛋白水平.结果 ①流感病毒能感染THP-1巨噬细胞并造成细胞凋亡.②低剂量氧化低密度脂蛋白（＜5μg/mL）促进细胞存活,高剂量氧化低密度脂蛋白（＞ 10 μg/mL）促进细胞凋亡.③5μg/mL氧化低密度脂蛋白单独预处理不影响巨噬细胞凋亡率（P =0.159）,但显著增加流感病毒（1＆#215;103、2＆#215;103、5＆#215;103和1＆#215;104 TCID50/mL）感染状态下的凋亡率（P =0.001、0.001、0.026和0.035）.④氧化低密度脂蛋白增强流感病毒感染引起的内质网相关分子GRP78和GADD153表达,促进巨噬细胞凋亡.结论 低剂量氧化低密度脂蛋白预处理可以增加流感病毒感染后巨噬细胞的凋亡,内质网应激在其中起重要作用.

Objective To investigate the effect and underlying mechanism of influenza virus infection in macrophages especially in low oxidized density lipoprotein （oxLDL） mimicked high lipid conditions.Methods Cell viability and apoptosis were detected by MTT assay and flow cytometry when macrophages were infected by different concentrations of influenza virus for 8 h,24 h and 48 h in the presence or absence of oxLDL.The expressions of GRP78,GADD153 mRNA were detected by RT-PCR and Western blot analysis.Results ①Influenza virus could infect THP-1 macrophages and induce cell apoptosis.②Low level oxLDL（〈 5 μg/mL）promoted cell survival,in contrast,high level oxLDL （〉 10 μg/mL）promoted cell apoptosis.③OxLDL pretreatment at 5 μg/mL did not influence macrophage apoptosis sole （P =0.159）,on the contrary,it increased macrophages apoptosis along with different concentrations （1 ＆#215; 103,2 ＆#215; 103,5 ＆#215; 103 and 1 ＆#215; 104TCID50/mL） of influenza virus infection.The P values were 0.001,0.001,0.026 and 0.035,respectively.④The expressions of GRP78 and GADD153 related to endoplasmic reticulum stress were significantly inclined compared with oxLDL absence groups in influenza virus infected conditions.Conclusions Endoplasmic reticulum stress plays a role in oxLDL pretreatment to promote influenza virus infection induced macrophages apoptosis.