氧化型脂蛋白(a)对血管内皮细胞血小板衍生生长因子B链表达的影响

Increased expression of platelet derived growth factor-B in human umbilical vein endothelial cells by oxidized lipoprotein(a)

目的 探讨氧化型脂蛋白 (a)〔ox Lp(a)〕对人脐静脉内皮细胞表达血小板衍生生长因子 B链 (PDGF B)的影响 ,以阐明其在动脉粥样硬化发生中的作用。 方法 在内皮细胞培养基中分别加入天然脂蛋白 (a)〔n Lp(a)〕与ox Lp(a)及天然低密度脂蛋白 (n LDL)与氧化型低密度脂蛋白(ox LDL) ,37℃温育。用细胞酶联免疫检测PDGF B蛋白的表达 ,同时用荧光免疫方法证实PDGF B蛋白表达 ,并用Northern杂交检测PDGF BmRNA的表达。 结果 ox Lp(a)增加内皮细胞PDGF B蛋白表达呈剂量依赖性 ,并且 5nmol/L及 2 0nmol/Lox Lp(a)分别使PDGF B表达明显增加了 (15 6± 18) %及 (2 19± 42 ) %。同时用免疫荧光证实ox Lp(a)促使PDGF B表达增强。比较相同浓度的n LDL、n Lp(a)、ox LDL、ox Lp(a) 4种脂蛋白的作用 ,显示ox Lp(a)的作用最强 ,10nmol/L的n LDL、n Lp(a)、ox LDL、ox Lp(a)分别使PDGF B表达增加了 (96± 17) %、(138± 19) %、(12 7± 11) %、(2 48± 41) %。Northern杂交检测结果显示 ,ox Lp(a)能促使PDGF BmRNA表达明显增加。 结论 ox Lp(a)能诱导内皮细胞表达PDGF B增强 ,这可能与Lp(a)致动脉粥样硬化作用机制有关。

Objective To investigate the effects of oxidized lipoprotein(a) 〔ox Lp(a)〕 on the expression of platelet derived growth factor B (PDGF B) in cultured human umbilical vein endothelial cells (HUVECs). Methods Native Lp(a) 〔n Lp(a)〕, native low density lipoprotein (n LDL), oxidized LDL (ox LDL) and ox Lp(a) were incubated with HUVECs at 37℃ for various time, cell ELISA was used to detect the expression of platelet derived growth factor B (PDGD B) protein. Meanwhile, fluorescein immuno assay was used to detect the expression of PDGF B protein and Northern blot was used to detect the PDGF B mRNA expression. Results Ox Lp(a) enhanced the levels of PDGF B in a dose dependent manner; it increased PDGF B in HUVECs by (156 ± 18)% at 5 nmol/L and (219 ± 42)% at 20 nmol/L. Moreover, ox Lp(a) was the most potent stimulus for PDGF B expression, 10 nmol/L n LDL, n Lp(a), ox LDL and ox Lp(a) increased the PDGF B expression by (96 ± 17)%、(138 ± 19)%、(127 ± 11)%、(248 ± 41)%, respectively. Furthermore, Northern blot analysis demonstrated that the amount of PDGF B mRNA was increased after treatment with ox Lp(a). Conclusions Ox Lp(a) can induce PDGF B expression in HUVECs, thus influencing the pathogenesis of athersclerosis.