Elevated adipose differentiation-related protein level in ovariectomized mice correlates with tissue-specific regulation of estrogen.

OBJECTIVE: Redistribution of adipose tissue in the abdomen during the menopausal transition is attributable mostly to estrogen drop with aging. Adipose differentiation-related protein (ADRP), a major component of lipid droplets, is closely related to the onset of lipid accumulation. We hypothesized that estrogen exerted its tissue-specific effect in reducing abdominal fat accumulation by regulation of ADRP. METHODS: Twenty-four female C57/BL6 mice aged 8 weeks were randomly divided into 3 groups: sham operation (Sham), bilateral ovariectomy (OVX), and OVX plus 17ß-estradiol (OVX + E2). After being fed 8 weeks of a high-fat diet, plasma lipid profiles including total cholesterol (TC), total triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) levels, body weight gain, visceral, and subcutaneous adipose tissue, adipocyte size, and ADRP expression were measured. RESULTS: In comparison to sham-operated mice, OVX mice presented a weight gain with higher plasma TC, TG, LDL-C levels, and lower HDL-C levels. E2 supplement ameliorated the increase in weight and lipid profiles. Elevated ADRP expression was observed in visceral adipose tissue of OVX mice, whereas treatment of estrogen suppressed the ADPR expression and reversed the fat accumulation in the abdomen. However, no significant difference of ADRP expression in subcutaneous adipose tissue was detected between sham, OVX, and OVX + E2 mice. CONCLUSIONS: Our findings suggested that enhanced ADRP expression in ovariectomized mice correlates with the tissue-specific regulation of estrogen, which may provide useful clues for further exploring the regulatory mechanism and corresponding anti-abdominal obesity treatment in postmenopausal women.