Objective: Premenopausal women demonstrate a distinctive gynoid body fat distribution and circulating estrogen status is associated with the maintenance of this adiposity patterning. Estrogen's role in modulation of regional adiposity may occur through estrogen receptors (ERs), which are present in human adipose tissue. The purpose of this study was to determine regional differences in the protein content of ERα, ERβ, and the G protein-coupled estrogen receptor (GPER) between the abdominal (AB) and gluteal (GL) subcutaneous adipose tissue of overweight-to-obese premenopausal women.
Materials/methods: Biopsies of the subcutaneous AB and GL adipose tissue were performed in 15 premenopausal women (7 Caucasian/8 African American, 25.1 ± 1.8 years, BMI 29.5 ± 0.5kg/m(2)). Adipose tissue protein content was measured by western blot analysis and correlation analyses were conducted to assess the relationship between ER protein content and anthropometric indices/body composition measurements.
Results: We found that ERα protein was higher in AB than GL (AB 1.0 ± 0.2 vs GL 0.67 ± 0.1 arbitrary units [AU], P=0.02), ERβ protein was higher in GL than AB (AB 0.78 ± 0.12 vs GL 1.3 ± 0.2 AU, P=0.002), ERα/ERβ ratio was higher in AB than GL (AB 1.9 ± 0.4 vs GL 0.58 ± 0.08 AU, P=0.007), and GPER protein content was similar in AB and GL (P=0.80) subcutaneous adipose tissue. Waist-to-hip ratio was inversely related to gluteal ERβ (r(2)=0.315, P=0.03) and positively related to gluteal ERα/ERβ ratio (r(2)=0.406, P=0.01).
Conclusions: These results indicate that depot specific ER content may be an important underlying determinant of regional effects of estrogen in upper and lower body adipose tissue of overweight-to-obese premenopausal women.
Keywords: AB; African American; BMI; Body fat distribution; Caucasian; DERKO; DHEA-S; DXA; ERα; ERβ; Estradiol; Estrogen Receptor α knockout mouse; Estrogen Receptor β knockout mouse; G protein-coupled estrogen receptor; GL; GPER; HDL; HOMA-IR; Homeostasis model assessment of insulin resistance; LDL; SAT; SHBG; Sex steroid receptors; TC; TG; WHR; abdominal; body mass index; dehydroepiandrosterone sulfate; double ERα/ERβ knockout mouse; dual-energy x-ray absorptiometry; estrogen receptor alpha; estrogen receptor beta; gluteal; high-density-lipoprotein cholesterol; low-density-lipoprotein cholesterol; sex hormone-binding globulin; subcutaneous adipose tissue; total cholesterol; triglycerides; waist-to-hip ratio; αERKO; βERKO.
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