PIM1调节氧化低密度脂蛋白诱导的ApoE^(-/-)小鼠血管平滑肌细胞表型转化  

PIM1 mediates oxidized low-density lipoprotein-induced phenotypic switching of vascular smooth muscle cells in ApoE^(−/−)mice

作　　者：付萌萌 钟耕瑞 徐梦琪 王小波 王汉琴 FU Mengmeng;ZHONG Gengrui;XU Mengqi;WANG Xiaobo;WANG Hanqin(Translational Medicine Research Center,Suizhou Hospital,Hubei University of Medicine,Suizhou 441300,China;Department of Anatomy,Basic Medical College,Hubei University of Medicine,Shiyan 442000,China)

机构地区：[1]湖北医药学院附属随州医院转化医学研究中心,湖北随州441300 [2]湖北医药学院基础医学院解剖学教研室,湖北十堰442000

出　　处：《中国病理生理杂志》2024年第10期1854-1863,共10页Chinese Journal of Pathophysiology

基　　金：国家自然科学基金资助项目(No.31670961);湖北医药学院研究生科技创新项目(No.YC2023018)。

摘　　要：目的:探讨莫洛尼小鼠白血病病毒前病毒整合位点1(PIM1)在氧化低密度脂蛋白(oxLDL)诱导的ApoE^(-/-)小鼠血管平滑肌细胞(VSMC)表型转化中的作用及机制。方法:8周龄ApoE^(-/-)雄性小鼠18只随机分为普通饮食组和高脂饮食组,每组9只。16周后取主动脉,HE染色观察内膜变化,Western blot法和免疫荧光法检测PIM1、VSMC表型相关蛋白α-平滑肌肌动蛋白(α-SMA)、平滑肌蛋白22α(SM22α)、骨桥蛋白(OPN)和CD68表达。体外用oxLDL(50 mg/L)诱导原代培养的ApoE^(-/-)小鼠主动脉平滑肌细胞表型转化,分别用PIM1特异性抑制剂SMI-4a、PIM1小干扰RNA(siPIM1)、糖酵解小分子抑制剂3-(3-吡啶基)-1-(4-吡啶基)-2-丙烯-1-酮(3PO)进行干预。用Western blot法和免疫荧光法检测PIM1和平滑肌表型相关蛋白的表达;用Western blot法检测糖酵解酶6-磷酸果糖-2-激酶/果糖-2,6-二磷酸酶3(PFKFB3)和己糖激酶2(HK2)表达,用乳酸测试盒检测VSMC上清乳酸分泌变化。结果:高脂饮食ApoE^(-/-)小鼠主动脉HE染色可见动脉粥样斑块形成。免疫荧光可见PIM1蛋白和合成表型蛋白OPN高表达在内膜下斑块组织内,收缩表型蛋白α-SMA主要分布在血管壁中膜层。主动脉壁Western blot结果显示,与普通饮食组相比,高脂饮食组PIM1蛋白表达显著增加(P<0.01),同时收缩表型蛋白(α-SMA和SM22a)表达显著减少,合成表型蛋白(OPN和CD68)表达显著增加(P<0.01)。体外细胞实验结果显示,oxLDL显著减少VSMC中α-SMA和SM22a表达,增加OPN和CD68表达(P<0.05或P<0.01),同时显著上调PIM1蛋白表达(P<0.01),增加糖酵解酶PFKFB3和HK2表达(P<0.05),伴随VSMC乳酸分泌水平升高(P<0.01)。SMI-4a处理和siPIM1转染VSMC,显著减弱了oxLDL以上诱导效果(P<0.05或P<0.01)。3PO显著抑制了oxLDL上调的糖酵解水平,同时抑制VSMC向合成表型的转化(P<0.05或P<0.01)。结论:PIM1高表达在ApoE^(-/-)小鼠动脉粥样硬化斑块中。VSMC表型转化与PIM1表达水平有关AIM:To investigate the role of proviral integration site for Moloney murine leukemia virus 1(PIM1)in the phenotypic switching of vascular smooth muscle cells(VSMCs)induced by oxidized low-density lipoprotein(oxLDL),and to explore the underlying mechanisms.METHODS:Eighteen male ApoE^(−/−)mice(8 weeks old)were randomly divided into general diet group and high-fat diet group,with 9 mice per group.After 16 weeks,aortic samples were analyzed using HE staining to observe plaque formation.In vitro,VSMCs were exposed to oxLDL to induce phenotypic transformation.Western blot and immunofluorescence were used to measure the protein expression levels of PIM1 and phenotypic markers includingα-smooth muscle actin(α-SMA),smooth muscle protein 22α(SM22α),osteopontin(OPN),and CD68.Glycolysis levels were assessed by detecting the expression of glycolytic enzymes 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase(PFKFB3)and hexokinase 2(HK2)by Western blot,and lactate secretion was measured using a lactate test kit.The effects of SMI-4a(a specific inhibitor of PIM1)and PIM1 small interfering RNA on oxLDL-induced phenotypic markers in VSMCs were evaluated.Moreover,the impact of 3-(3-pyridinyl)-1-(4-pyridinyl)-2-propen-1-one(3PO;a glycolysis inhibitor)on oxLDL-induced phenotypic switching and glycolysis in VSMCs was investigated.RESULTS:HE staining revealed atherosclerotic plaque formation in the aortas of ApoE^(−/−)mice fed with high-fat diet.Immunofluorescence showed high accumulation of PIM1 and OPN in the tunica intima of atherosclerotic plaques.Compared with control group,aortic plaques exhibited significantly elevated levels of PIM1,OPN and CD68 proteins(P<0.01),accompanied by reduced expression of contractile phenotype markersα-SMA and SM22α(P<0.01).In vitro,oxLDL treatment led to gradual decrease inα-SMA and SM22αexpression(P<0.05 or P<0.01),while OPN and CD68 expression increased(P<0.05 or P<0.01).Moreover,oxLDL significantly up-regulated the protein expression of PIM1,PFKFB3 and HK2,and increased lactate se

关 键 词：PIM1蛋白 血管平滑肌细胞 表型 氧化低密度脂蛋白 

分 类 号：Q78[生物学—分子生物学] R322.1[医药卫生—人体解剖和组织胚胎学] R543[医药卫生—基础医学]