羟基红花黄色素A上调低氧状态下血管内皮细胞中缺氧诱导因子-1α的表达

羟基红花黄色素A(hydroxysafflor yellow A，HSYA)是从菊科植物红花中提取的查尔酮类化合物。本实验观察HSYA对低氧状态(1% O₂)下人脐静脉内皮细胞株(Eahy926)增殖的促进作用及其调节Eahy 926细胞中林希氏基因(von Hippel-Lindau gene，VHL)，抑癌基因p53(tumor suppressor gene p53，p53)和降解缺氧诱导因子-1α(hypoxia-inducible factor 1α，HIF-1α)的作用。采用MTT法测定低氧状态下HSYA(100、 10和1 μmol·L^-1)对Eahy 926细胞增殖率的影响。免疫组织化学方法测定VHL与p53蛋白表达数量和定位。RT-PCR方法检测细胞中VHL、 p53和HIF-1α的转录水平。Western blotting方法检测VHL、 p53和HIF-1α的蛋白表达。与低氧模型对照组相比，HSYA(100 μmol·L^-1)促使细胞增殖率升高，HIF-1α转录和蛋白表达水平显著增强，呈时间依赖性。给药8 h后，VHL与p53的蛋白表达和转录水平均明显降低。HSYA诱导HIF-1α表达增加并提高低氧状态下细胞增殖率的作用，可能通过抑制VHL和p53两种HIF-1α的降解调节因子实现。

Hydroxysafflor yellow A up-regulates HIF-1α via inhibition of VHL and p53 in Eahy 926 cell line exposed to hypoxia

In present study, we investigated the mechanism of regulating HIF-1alpha expression by hydroxysafflor yellow A (HSYA) in Eahy 926 cell line under 1% O2 hypoxia. Eahy 926 cells were incubated with HSYA (100, 10 and 1 micromol x L(-1)) under hypoxia for the indicated time after treatment. Cell proliferation rate was detected using MTT assays. VHL and p53 location and protein expression were analyzed by immunocytochemical stain. HIF-1alpha, VHL and p53 mRNA expression were detected by RT-PCR. Protein expression of HIF-1alpha, VHL and p53 were assayed by Western blotting method. HSYA at 100 micromol x L(-1) increased Eahy 926 cells proliferation rate under hypoxia. HIF-1alpha mRNA and protein expression were up-regulated in the presence of HSYA. VHL, p53 mRNA and protein expression decreased significantly after 8 hours of treatment under hypoxia. HSYA protected Eahy 926 cells from hypoxia, and up-regulated HIF-1alpha expression partially via its inhibition of VHL and p53 expression.