过氧化物酶体增殖物激活受体α诱导内源性成纤维细胞生长因子21表达水平变化对氧化修饰的低密度脂蛋白引起的鼠内皮细胞凋亡的影响

Oxidized low density lipoprotein and peroxisome proliferator-activated receptor α induced endogenous fibroblast growth factor 21 upregulation is protective against apoptosis in cardiac endothelial cells

目的 通过观察氧化修饰的低密度脂蛋白（ox-LDL）引起心脏血管内皮细胞损伤时,内源性成纤维细胞生长因子21（FGF21）基因表达及蛋白分泌水平的变化,以及过氧化物酶体增殖物激活受体α（PPARα）刺激内源性FGF21生成增加时,对ox-LDL诱导细胞凋亡的影响,探讨内源性FGF21对动脉粥样硬化早期内皮功能的保护作用.方法 分离并培养成年Wistar大鼠心脏微血管内皮细胞,给予ox-LDL溶液,建立心脏血管内皮细胞损伤模型,以实时（real time）PCR及ELlSA法分析FGF21基因及蛋白水平变化,并给予PPARα配基苯扎贝特（分为50、100及200μmol/L组）,诱导FGF21高表达,ELISA法观察细胞凋亡情况.结果 10、50及100μg/ml ox-LDL溶液组,FGF21基因表达及蛋白分泌越来越高.50及100 μg/ml ox-LDL组FGF21 mRNA表达水平,100 μg/ml ox-LDL组FGF21蛋白分泌水平,200 μmol/L苯扎贝特组诱导FGF21水平均显著高于溶剂对照组（P均＜0.05）.200 μmol/L苯扎贝特＋100μg/ml ox-LDL组细胞凋亡水平显著低于100 μg/ml ox-LDL组（P＜O.05）.结论 ox-LDL诱导心血管内皮细胞损伤时FGF21分泌水平可反应性增高,且呈剂量依赖性.PPARα配基苯扎贝特可引起FGF21表达水平增高,对ox-LDL诱导的内皮细胞凋亡起到一定的抑制作用,提示FGF21可能作为一种心血管内源性保护因子,拮抗动脉粥样硬化早期心血管内皮功能障碍.

Objective To investigate the effect of peroxisome proliferator-activated receptor （PPAR） α agonist bezafibrate and oxidized low density lipoprotein （ox-LDL） on fibroblast growth factor 21 （FGF21）expression and apoptosis in cardiac endothelial cells. Methods The mRNA level of FGF21 was determined by real time-PCR and the protein concentration of FGF21 in culture media was detected by enzyme-linked immunosorbent assay in cultured cardiac microvascular endothelial cells （CMECs） incubated with 10, 50,100 μg/ml ox-LDL, 50, 100 or 200 μmol/L bezafibrate alone or in combination with 100 μg/ml ox-LDL. CMECs apoptosis in various treatment groups was also determined. Results FGF21 mRNA and protein expressions were significantly upregulated in proportion to increased ox-LDL, and 200 μmol/L bezafibrate alone also significantly upregulated FGF21 expression and CMECs apoptosis was significantly reduced in 200 μ mol/L bezafibrate ＋ 100 μg/ml ox-LDL group compared to 100 μg/ml ox-LDL group（ P 〈0. 05 ）. Conclusions Our data suggest that bezafibrate and ox-LDL induced upregulation of FGF21 might mediate the protective effect against apoptosis. Endogenous FGF21 could thus play important roles in improving the endothelial function at the early stage of atherosclerosis and slowing the development of coronary heart disease.