阿托伐他汀减轻巨噬细胞内质网应激及其介导的细胞凋亡

目的 探讨阿托伐他汀对7-酮胆固醇（7-KC）诱导的巨噬细胞内质网应激及细胞凋亡的影响。方法 AopE-/-小鼠左肾动脉和左颈总动脉联合部分结扎建立颈动脉易损斑块模型。采用HE染色方法观察斑块病理学改变，用免疫荧光结合激光扫描共聚焦显微镜技术检测斑块中内质网应激(ER stress)相关蛋白CHOP及磷酸化PERK（p-PERK）的表达。体外培养小鼠巨噬细胞RAW264.7，给予7-KC、H2O2或联合阿托伐他汀处理后，蛋白质免疫印迹方法（Western blot）测定ER stress相关蛋白CHOP、p-PERK 、XBP-1s及凋亡相关蛋白cleaved caspase-3的表达。结果 AopE-/-小鼠颈动脉易损斑块局部ER stress相关蛋白CHOP的表达及PERK磷酸化水平明显上调；7-KC可诱导小鼠巨噬细胞ER stress，进而诱导细胞凋亡；同时，氧化应激诱导剂H2O2也可通过诱导小鼠巨噬细胞ER stress介导细胞凋亡；而阿托伐他汀可抑制7-KC和H2O2诱导的巨噬细胞ER stress及其介导的细胞凋亡。结论 ER stress可能参与AS易损斑块的形成；阿托伐他汀可通过减少细胞内氧化应激的水平，减轻巨噬细胞ER stress，从而抑制细胞凋亡。

Atorvastatin alleviates endoplasmic reticulum stress and apoptosis in macrophages

AIM To investigate the effect of atorvastatin on 7-ketocholesterol (7-KC)-induced endoplasmic reticulum stress (ER stress) and apoptosis in macrophages. METHODS We generated an ApoE-/- mouse model of vulnerable carotid atherosclerotic plaque by partial ligation of the left common carotid artery and left renal artery. The pathological changes of atherosclerotic plaques were observed by hematoxylin-eosin (HE) staining and the expression level or phosphorylation status of ER stress-associated proteins (CHOP and p-PERK) were detected by immunofluorescence staining. Macrophages (murine RAW 264.7 cells) were cultured and incubated with 7-KC or H2O2 with or without pretreatment with atorvastatin. ER stress-associated proteins (CHOP, p-PERK, XBP-1s) and apoptotic protein (cleaved caspase-3) were measured by Western blotting. RESULTS Vulnerable carotid atherosclerotic plaques from ApoE-/- mice showed induction of ER stress, as indicated by elevated CHOP levels and PERK phosphorylation. Levels of CHOP expression, PERK phosphorylation and cleavage of caspase-3 were elevated after exposure RAW264.7 cells to 7-KC, as well as to the direct inducer of oxidative stress H2O2. Atorvastatin inhibited 7-KC- and H2O2-induced ER stress and apoptosis in RAW264.7 cells in vitro. CONCLUSION 7-KC and oxidative stress induce ER stress and apoptosis in macrophages in vulnerable atherosclerotic plaques. Atorvastatin inhibits ER stress and apoptosisvia reducing oxidative stress.