雌激素通过雌激素受体上调载脂蛋白M表达

Estrogen increases apolipoprotein M through estrogen receptor

目的研究雌激素对载脂蛋白M的影响。方法采用RT—PCR法检测不同浓度、不同作用时间雌激素处理HepG2细胞以及雌激素和雌激素受体拮抗剂共同处理后，HepG2细胞载脂蛋白MmRNA的表达；将sD雌性大鼠分为5组：去卵巢组（OVX）；假手术组（Sham）；去卵巢＋苯甲酸雌二醇（EB）组（OVX＋EB）；正常大鼠组（对照组）；正常大鼠＋EB组（EB组），术后给予不同剂量的EB。常规生化检测血液标本中血清甘油三酯、总胆固醇、低密度脂蛋白胆固醇（LDL）和高密度脂蛋白胆固醇（HDL），RT—PCR和Western印迹检测鼠apoM表达。结果雌激素上调HepG2细胞载脂蛋白M的表达，这种效应呈剂量和时间依赖性，可以被ER拮抗剂抑制。术后第1个月，OVX＋EB组和EB组大鼠apoMmRNA水平以及血清apoM、HDL、总胆固醇、甘油三酯和LDL水平分别较OVX组和对照组大鼠有显著性升高（P〈0．05）。结论雌激素通过ER途径上调载脂蛋白M的表达。

Objective To explore the effects of estrogen on apolipoprotein M （apoM）. Methods ApoM mRN A was assayed in HepG2 cells by RT-PCR after incubation of estrogen with or without estrogen receptor antagonist at different concentrations and durations. SD female rats were divided into five groups： OVX group, Sham group, OVX＋EB group, normal group and normal＋ EB group. From a week of being operated, the rats were injected subcutaneously estradiol benzoate or vehicle. After 12-hrs fasting, serum levels of triglycerides （ TG ） , LDL- cholesterol, HDL-cholesterol, total cholesterol （TC） at months 1, 2 and 3 after operation were measured. The expression of apoM in rats was detected by using real time RT-PCR and Western blot. Results Estrogen increased mRNA levels of apoM and apoAI in the HepG2 ceils with a dose- and time-dependent manner, which could be abolished by addition of estrogen receptor antagonist. Serum apoM, TG, TC, HDL and LDL levels were significantly increased in the ovariectomized or normal rats which received estrogen treatment than those in OVX or normal group rats at month 1 after treatments. Conclusions Estrogen upregulates apoM expression via its receptor.