PCSK9降解ApoER2对ApoE/ApoER2抗炎作用的影响

Effect of ApoER2 degradation by PCSK9 on the anti-inflammatory effect of ApoE/ApoER2

[目的]探讨前蛋白转化酶枯草溶菌素9(PCSK9)对载脂蛋白E(ApoE)受体2(ApoER2)的降解作用与ApoE/ApoER2抗炎作用之间的关系。[方法]体外培养人脐静脉内皮细胞(HUVEC)和HepG2细胞,采用Western blot和ELISA检测脂多糖(LPS)对HUVEC中Toll样受体(TLR4)、肿瘤坏死因子α(TNF-α)、白细胞介素6(IL-6)和PCSK9表达及分泌的影响;ApoE3对LPS诱导的HUVEC中TNF-α、IL-6、PCSK9和ApoER2表达及分泌的影响;ApoE的三种亚型(ApoE2、ApoE3和ApoE4)对非炎症状态下HUVEC和HepG2细胞中PCSK9及ApoER2表达的影响;PCSK9对HUVEC中ApoER2、TNF-α和IL-6表达及分泌的影响。[结果]Western blot和ELISA检测结果显示,LPS可以上调HUVEC中TLR4、TNF-α、IL-6和PCSK9的表达及分泌。ApoE3抑制LPS诱导的炎症反应,并上调ApoER2的表达及分泌。ApoE的三种亚型(ApoE2、ApoE3和ApoE4)对非炎症状态下HUVEC和HepG2细胞中PCSK9及ApoER2的表达无明显影响。不同剂量(0、0.5、1.0和2.5 mg/L)的人重组PCSK9处理HUVEC 24 h,Western blot和ELISA检测结果显示,PCSK9上调TNF-α、IL-6的表达及分泌,下调ApoER2的表达。[结论]PCSK9通过对ApoER2的降解来拮抗ApoE/ApoER2的抗炎作用。

Aim To investigate the relationship between apolipoprotein E(ApoE)receptor 2(ApoER2)degradation by proprotein convertase subtilisin kexin 9(PCSK9)and the anti-inflammatory effect of ApoE/ApoER2.Methods Human umbilical vein endothelial cells(HUVEC)and HepG2 cells were cultured in vitro,Western blot and ELISA were used to detect the effects of lipopolysaccharide(LPS)on the expression and secretion of Toll-like receptor(TLR4),tumor necrosis factor-α(TNF-α),interleukin-6(IL-6)and PCSK9 in HUVEC;the effects of ApoE3 on the expression and secretion of TNF-α,IL-6,PCSK9 and ApoER2 in HUVEC induced by LPS;the effects of three isoforms of ApoE(ApoE2,ApoE3 and ApoE4)on the expression of PCSK9 and ApoER2 in HUVEC and HepG2 cells under non-inflammatory conditions;and the effects of PCSK9 on the expression and secretion of ApoER2,TNF-αand IL-6 in HUVEC.Results Western blot and ELISA showed that LPS up-regulated the expression and secretion of TLR4,TNF-α,IL-6 and PCSK9 in HUVEC;ApoE3 inhibited LPS-induced inflammatory responses,and up-regulated ApoER2 expression and secretion;the three isoforms of ApoE(ApoE2,ApoE3 and ApoE4)had no effect on the expression of PCSK9 and ApoER2 in HUVEC and HepG2 cells under non-inflammatory conditions.Different doses(0,0.5,1.0 and 2.5 mg/L)of recombinant human PCSK9 were used to treat HUVEC for 24 h,Western blot and ELISA showed that PCSK9 up-regulated the expression and secretion of TNF-αand IL-6,and down-regulated the expression of ApoER2.Conclusion PCSK9 antagonizes the anti-inflammatory effects of ApoE/ApoER2 by degrading ApoER2.