脂多糖诱导Toll样受体4对载脂蛋白E基因敲除小鼠动脉粥样硬化斑块内质网应激的影响  

Effects of lipopolysaccharide-induced toll-like receptor 4 on endoplasmic reticulum stress in atherosclerotic plaques of polipoprotein E gene knockout mice

作　　者：郭晓坤[1] 夏晓爽[2] 王佩璐[2] 王林[1] 李新[1] Guo Xiaokun;Xia Xiaoshuang;Wang Peilu;Wang Lin;Li Xin(Department of Geriatrics,the Second Hospital of Tianjin Medical University,Tianjin 300211,China;Department of Neurology,the Second Hospital of Tianjin Medical University,Tianjin 300211,China)

机构地区：[1]天津医科大学第二医院老年病科,300211 [2]天津医科大学第二医院神经内科,300211

出　　处：《中华老年医学杂志》2020年第6期695-699,共5页Chinese Journal of Geriatrics

摘　　要：目的:通过观察脂多糖(LPS)诱导的Toll样受体4(TLR4)对载脂蛋白E基因敲除(ApoE-/-)小鼠动脉粥样硬化斑块内质网应激通路蛋白表达水平的影响,探讨内质网应激对小鼠动脉粥样硬化斑块稳定性的影响。方法:2015年10月至2016年2月选择ApoE-/-小鼠24只,高脂喂养10周后数字抽签随机分为对照组、LPS组、TLR4的特异性抑制剂TAK(TAK组),各8只。干预10周后取眼球血检测总胆固醇(TC)、三酰甘油(TG)、氧化型低密度脂蛋白(ox-LDL)。处死小鼠留取颈动脉和主动脉标本。免疫组化法检测颈动脉斑块巨噬细胞(MOMA-2)、平滑肌肌动蛋白(α-actin)、TLR4、白细胞介素1β(IL-1β)、IL-6、肿瘤坏死因子α(TNFα)及κ基因结合核因子(NFκB)的表达。免疫印迹法检测PKR样真核起始因子2α激酶(PERK)、C/EBP同源蛋白(CHOP)、糖调节蛋白78(GRP78)的水平。结果:LPS组小鼠与对照组和TAK组小鼠比较,TC(25.0±2.3)mmol/L比(20.2±1.6)mmol/L、(20.8±2.6)mmol/L、TG(1.3±0.1)mmol/L比(1.3±0.1)mmol/L、(1.0±0.1)mmol/L、ox-LDL(17.4±1.3)mmol/L比(15.8±1.6)mmol/L、(12.1±1.1)mmol/L水平升高(P<0.05);斑块形态学及病理学比较,LPS组小鼠动脉粥样硬化斑块范围大,巨噬细胞含量增多(P<0.05),平滑肌细胞含量减少(P<0.05),斑块TLR4、IL-1β、IL-6、TNFα及NFκB的表达水平较其他两组增加(P<0.05);PERK、CHOP、GRP78的表达水平增加(P<0.05)。与对照组比较,TAK组PERK、CHOP、GRP78的表达水平减少(P<0.05)。LPS组TLR4,质网应激通路蛋白PERK、CHOP、GRP78的表达水平增加。结论:LPS诱导的TLR4可上调内质网应激通路蛋白的表达,且引起内质网应激下游炎性细胞因子分泌增加,加重脂质代谢紊乱,增加动脉硬化斑块的不稳定性。Objective To investigate the effects of endoplasmic reticulum(ER)stress on the stability of atherosclerotic plaques in mice by examining the action of lipopolysaccharide(LPS)-induced Toll-like receptor 4(TLR4)on the protein expression levels in the ER stress pathway in atherosclerotic plaques of polipoprotein E gene knockout(ApoE-/-)mice.Methods From October 2015 to February 2016,24 ApoE-/-mice were randomly divided into the control group,the LPS group and the TAK group after 10 weeks of high-fat feeding(n=8,each group).After 10 weeks of intervention,peripheral blood was extracted by removing the eyeballs for the measurement of total cholesterol(TC),triglycerides(TG)and oxidized low density lipoprotein(ox-LDL).Then mice were sacrificed to obtain carotid and aortic specimens.Immunohistochemistry was used to detect the expression of carotid plaque macrophages(MOMA-2),smooth muscle actin(α-actin),TLR4,interleukin-1β(IL-1β),interleukin-6(IL-6),tumor necrosis factor-α(TNFα)and nuclear factor-κ-gene binding(NFκB).Western blotting was used to determine the expression of PKR-like eukaryotic initiation factor 2αkinase(PERK),C/EBP-homologous protein(CHOP)and glucose-regulated protein 78(GRP78).Results The levels of TC,TG and ox-LDL were elevated in the LPS group,compared with the control and TAK groups[(25.0±2.3)mmol/L vs.(20.2±1.6)mmol/L and(20.8±2.6)mmol/L,(1.3±0.1)mmol/L vs.(1.3±0.1)mmol/L and(1.0±0.1)mmol/L,(17.4±1.3)mmol/L vs.(15.8±1.6)mmol/L and(12.1±1.1)mmol/L,P<0.05].The comparison of plaque morphology and pathology showed that the LPS group had a wider range of atherosclerotic plaques,more macrophages and fewer vascular smooth muscle cells than the control and TAK groups(P<0.05).The expression of TLR4,IL-1β,IL-6,TNFα,NFκB,PERK,CHOP and GRP78 was higher in the LPS group than in the control and TAK groups(P<0.05).Compared with the control group,the expression of PERK,CHOP and GRP78 was lower in the TAK group(P<0.05).The expression of TLR4,PERK,CHOP and GRP78 was higher in the LPS group.Conclusion

关 键 词：脂多糖类 TOLL样受体4 动脉粥样硬化 内质网 

分 类 号：R543.5[医药卫生—心血管疾病]