The Role of Estrogen in Gender Differences in Adipocyte Biology

Abstract

BackgroundIt has been established that males and females differ in their adipose tissue deposition; however, a full understanding of the adipocyte biology involved is needed. The objective of our study is to explore the role estrogen plays in gender differences in obesity, specifically in adipocyte biology.MethodsTo determine the role of estrogen in gender differences in the susceptibility to obesity we used C57BL/6J mice (15/group): 1) males 2) nonovariectomized females 3) ovariectomized females and 4) ovariectomized females supplemented with estrogen, which were randomized to the following diets: 30% calorie‐restricted, low‐fat or high‐fat diet. We measured weight gain, percent body fat, abdominal adipose tissue, and adipocyte size. Additionally, we assessed adipocyte biology by using QRTPCR to detect mRNA levels of key adipocyte biology genes.ResultsMale mice were more susceptible to diet induced obesity compared to female mice. Removal of the ovaries caused the female mice to mimic the males' susceptibility to obesity, and supplementation of estrogen to the ovariectomized females restored their protection to obesity. In the high‐fat diet groups, males and ovariectomized females gained more abdominal adipose tissue due to increased adipocyte size. Moreover, males and ovariectomized females had significantly higher peroxisome proliferator‐activated receptor‐gamma and leptin mRNA levels. Male mice also had significantly higher lipin1 and Ccaat‐enhancer‐binding protein‐beta mRNA levels compared to intact females and ovariectomized females supplemented with estrogen.ConclusionEstrogen protects female mice from obesity by modulating adipocyte biology thru key adipogenic genes.Grant Support: This work was supported by American Cancer Society grant.