肝X受体激动剂通过激活SIRT1信号级联改善Aβ诱导的视网膜色素上皮细胞炎症和凋亡反应  

Liver X receptor agonist ameliorates amyloid β-induced inflammation and apoptosis in retinal pigment epithelial cells by activating SIRT1 signaling cascade

作　　者：甘敏 周巧雅 洪美静 李雪[1] 彭惠[1] GAN Min;ZHOU Qiaoya;HONG Meijing;LI Xue;PENG Hui(Department of Ophthalmology,Chongqing Eye Institute,Chongqing Key Laboratory of Ophthalmology,the First Affiliated Hospital of Chongqing Medical University,Chongqing,400016,China)

机构地区：[1]重庆医科大学附属第一医院眼科,眼科学重庆市市级重点实验室,重庆市眼科研究所,重庆400016

出　　处：《第三军医大学学报》2020年第14期1398-1406,共9页Journal of Third Military Medical University

基　　金：国家自然科学基金面上项目(81670881)。

摘　　要：目的探讨LXR-SIRT1调控轴在淀粉样β(amyloidβ,Aβ)诱导的视网膜上皮(retinal pigment epithelial,RPE)细胞炎症和凋亡中的作用。方法体外培养ARPE-19细胞系,收集湿性年龄相关性黄斑变性(age-related macular degeneration,AMD)患者和正常受试者的人外周血单个核细胞(human peripheral blood mononuclear cell,PBMC)并检测其中沉默信息调节因子1(silencing information regulator 1,SIRT1)的mRNA表达。用1.0、5.0μmol/L的Aβ1-40和5.0μmol/L Aβ40-1处理ARPE-19细胞24 h,Real-time PCR检测SIRT1、IL-1β、p21在ARPE-19细胞中的表达,探讨Aβ对ARPE-19细胞炎症、凋亡的影响。用5.0μmol/L Aβ1-40和5.0μmol/L TO90处理ARPE-19细胞,Western blot检测SIRT1、LXRα、ace-NF-κB、NF-κB、ace-p53、p53、p21的表达,研究Aβ1-40刺激及TO90预处理对SIRT1信号级联的影响。在敲低SIRT1后,Western blot检测NF-κB和p53信号通路的表达,进一步验证TO90对SIRT1信号级联的调控作用。结果SIRT1在湿性AMD患者的PBMC中明显下调(P<0.01)。Aβ1-40刺激ARPE-19细胞后,SIRT1在mRNA及蛋白水平明显下调(P<0.05),p21在mRNA及蛋白水平明显上调(P<0.05),IL-1β在基因水平明显上调(P<0.05),ace-NF-κB、NF-κB、ace-p53、p53在蛋白水平显著上调(P<0.05),而TO90预处理则可逆转Aβ1-40对这些因子的调节(P<0.05)。SIRT1敲低后,TO90对ace-NF-κB、NF-κB、ace-p53、p53上调的逆转作用显著下降(P<0.05)。结论LXR激动剂通过激活SIRT1信号级联改善Aβ诱导的ARPE-19细胞炎症及凋亡反应。Objective To investigate the role of liver X receptor(LXR)-SIRT1 regulatory axis in inflammation and apoptosis of retinal pigment epithelial(RPE)cells induced byβ-amyloid(Aβ).Methods Human peripheral blood mononuclear cells(PBMCs)were collected from patients with wet agerelated macular degeneration(AMD)and normal subjects for detection of SIRT1 mRNA expression.And then,human RPE cell line ARPE-19 stimulated with 1.0,5.0μmol/L Aβ1-40 or 5.0μmol/L Aβ40-1 was examined for expression of SIRT1,IL-1βand p21 using real-time PCR to investigate the effects of Aβon cell inflammation and apoptosis;Subsequently,the expression levels of SIRT1,LXRα,ace-NF-κB,NF-κB,acep53,p53,and p21 proteins in ARPE-19 cells treated with 5.0μmol/L Aβ1-40,5.0μmol/L TO90,or both were detected using Western blotting to analyze the effect of Aβ1-40 stimulation and TO90 pretreatment on SIRT1 signaling cascade.Finally,after knocking down SIRT1,the expression of NF-κB and p53 signaling pathways was detected by Western blot analysis to further verify the regulatory effect of TO90 on the SIRT1 signaling cascade.Results SIRT1 was significantly down-regulated in the PBMCs of patients with wet AMD(P<0.05).Aβstimulation of ARPE-19 cells caused obvious downregulation of SIRT1(P<0.05)and upregulation of p21 at both the mRNA and protein levels(P<0.05),upregulation of IL-1βat the mRNA level(P<0.05),and upregulation of ace-NF-κB,NF-κB,ace-p53,and p53 at the protein level(P<0.05);TO90 pretreatment effectively abolished the effects of Aβon these factors(P<0.05).After SIRT1 knockdown,the reverse effect of TO90 on the upregulation of ace-NF-κB,NF-κB,ace-p53,and p53 was significantly reduced(P<0.05).Conclusion LXR agonists improve Aβ-induced inflammation and apoptosis in ARPE-19 cells by activating the SIRT1 signaling cascade.

关 键 词：视网膜色素上皮 肝X受体 沉默信息调节因子1 淀粉样β 年龄相关性黄斑变性 

分 类 号：R329.25[医药卫生—人体解剖和组织胚胎学] R774.5[医药卫生—基础医学]