CDK5介导的PPARγ磷酸化在动脉粥样硬化泡沫细胞形成过程中的作用  

The role of CDK5-mediated PPARγ phosphorylation in the formation of foam cells in atherosclerosis

作　　者：沈娜 贺晶[3] 邸研博[2] 刘勇 田凤石[3] 刘运德[1] SHEN Na;HE Jing;DI Yan-bo;LIU Yong;TIAN Feng-shi;LIU Yun-de(School of Medical Laboratory, Tianjin Medical University, Tianjin 300203, China;Central Laboratory, Tianjin 4th Center Hospital;Department of Cardiology, Tianjin 4th Center Hospital)

机构地区：[1]天津医科大学医学检验学院,300203 [2]天津市第四中心医院中心实验室 [3]天津市第四中心医院心血管内科

出　　处：《天津医药》2019年第10期1045-1049,共5页Tianjin Medical Journal

基　　金：中国中青年临床研究基金-VG基金(2017-CCA-VG-021);天津市卫生行业重点攻关项目(16KG146);天津市慢性病防治科技重大专项(17ZXMFSY00200)

摘　　要：目的探讨细胞周期素依赖蛋白激酶5(CDK5)介导的过氧化物酶体增殖物激活受体γ(PPARγ)磷酸化在动脉粥样硬化中的作用。方法常规培养小鼠Raw264.7巨噬细胞,实验设对照组(C组)、氧化低密度脂蛋白(ox-LDL)组(O组,50mg/Lox-LDL)、Roscovitine+ox-LDL组(R组,15μmol/LRoscovitine+50mg/Lox-LDL)。待细胞融合至70%左右,R组加入15μmol/LRoscovitine预处理30min,之后O组和R组分别加入50mg/Lox-LDL继续培养24h,使其转化为泡沫细胞;C组不作处理。利用Westernblot检测各组pPPARγ、tPPARγ、p35和CDK5蛋白表达的变化,油红O染色和异丙醇萃取实验分析各组细胞内脂质聚积情况,酶法测定细胞内胆固醇含量,反转录PCR(RT-PCR)检测各组ox-LDL摄取相关基因CD36、SR-A1和胆固醇外流相关基因ABCA1、ABCG1的mRNA表达水平。结果ox-LDL诱导后,O组pPPARγ/tPPARγ比值、p35/CDK5比值、细胞内脂质聚积、总胆固醇含量、游离胆固醇含量、胆固醇酯/总胆固醇比值均较C组明显升高(P<0.05);CDK5抑制剂干预后,R组上述指标均较O组降低(P<0.05)。RTPCR结果显示,ox-LDL诱导后,O组ox-LDL摄取相关基因CD36、SR-A1的mRNA表达水平升高,而胆固醇外流相关基因ABCA1、ABCG1的mRNA表达水平降低(P<0.05);CDK5抑制剂干预后,上述指标变化与O组呈相反趋势(P<0.05)。结论CDK5/pPPARγ途径参与动脉粥样硬化泡沫细胞的形成。Objective To investigate the role of cyclin-dependent kinases 5 (CDK5)- mediated PPARγphosphorylation in atherosclerosis. Methods Raw264.7 macrophages were induced by ox-LDL to differentiate into foam cells, and then CDK5 inhibitor was used as the intervent. The experimental cells were divided into control group (C group), ox-LDL group (O group, 50 mg/L ox-LDL) and roscovitine group (50 mg/L ox-LDL+15 μmol/L Roscovitine). Expressions of pPPARγ, tPPARγ, p35 and CDK5 protein were detected by Western blot assay. Lipid accumulation was analyzed by oil red O staining and isopropyl alcohol extraction experiments. Levels of cholesterol content in macrophages were measured by enzymatic method. Expression of ox-LDL uptake related genes CD36, SR-A1 and cholesterol efflux related genes ABCA1 and ABCG1 were detected by RT-PCR. Results After ox-LDL induction, the ratios of pPPARγ/tPPARγ and p35/CDK5 significantly increased, and lipid accumulation, total cholesterol content, free cholesterol content and the ratio of cholesterol ester/total cholesterol were up-regulated significantly in O group compared with those of C group (P <0.05). RT-PCR showed that expression levels of ox-LDL uptake-related genes CD36 and SR-A1 mRNA increased, while the expression levels of cholesterol efflux-related genes ABCA1 and ABCG1 decreased in O group (P <0.05). After intervention with CDK5 inhibitor, the above indicators showed the opposite trend compared with those of O group (P <0.05). Conclusion CDK5/ pPPARγ pathway is involved in the formation of foam cells in atherosclerosis.

关 键 词：动脉粥样硬化 泡沫细胞 细胞周期蛋白依赖激酶5 过氧化物酶体增殖物激活受体 CD36 SR-A1 ABCA1 ABCG1 

分 类 号：R541.4[医药卫生—心血管疾病]