Estrogen increases apolipoprotein M through estrogen receptor / 中华内分泌代谢杂志

ABSTRACT

Objective To explore the effects of estrogen on apolipoprotein M ( apoM ).Methods ApoM mRNA 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 groupsOVX group,Sham group,OVX+ EB group,normal group and normal + EB group.From a week of being operated,the rats were injected subcutaneously estradiol beuzoate 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 cells 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.