Defining the role of an endothelial-adipocyte precursor axis in adipocyte hyperplasia

项目摘要 肥胖，其被定义为白色脂肪组织（WAT）的过度积累，与 许多代谢、炎症和心血管紊乱的发展。然而， 与代谢疾病相关的内脏脂肪（VWAT）的积累，而 皮下脂肪（SWAT）被认为可以防止肥胖相关疾病的发展。性 已知激素影响脂肪的积累、VWAT和VWAT之间的脂肪分布， 皮下脂肪（SWAT）和代谢疾病的发展，但确切的机制， 性激素对脂肪功能和分布的影响尚不清楚。 我们以前已经证明，有一种肥胖特异性的脂肪形成机制， 以性别特异性模式增生。雌激素在这一过程中发挥作用，其中外源性雌激素驱动 雄性小鼠脂肪细胞增生的雌性样模式（VWAT和SWAT），而缺乏全身性 雌性小鼠中的雌激素导致雄性样模式（仅VWAT反应）。初步数据显示， 在缺乏全身性雌激素的情况下，雌激素信号仍然在VWAT脂肪细胞增生中起直接作用， 肥胖症的发病。我们发现VWAT内皮细胞表达芳香化酶，从而产生芳香化酶。 雄性和卵巢切除雌性脂肪细胞增生所需的雌激素。我们认为芳香化酶 VWAT内皮细胞的表达受糖皮质激素控制，将雌激素的VWAT特异性作用与 下丘脑-垂体-肾上腺（HPA）轴。根据我们的初步数据，我们假设雌激素和 糖皮质激素参与调节致肥胖脂肪形成的内皮细胞-脂肪细胞前体轴， 从而影响WAT的分布并影响代谢疾病。在这里，我们将建立脂肪的作用- 在肥胖和代谢疾病中产生雌激素，确定调节VWAT中芳香酶的机制 内皮细胞和定义的分子机制，调节雌激素作用的脂肪细胞前体。

Project Summary Obesity, which is defined as the excess accumulation of white adipose tissue (WAT) is associated with the development of numerous metabolic, inflammatory, and cardiovascular derangements. However, it is the accumulation of visceral adipose (VWAT) that is associated with metabolic diseases, while the accumulation of subcutaneous adipose (SWAT) is thought to protect against the development of obesity-associated disease. Sex hormones are known to influence both the accumulation of adipose, adipose distribution between VWAT and subcutaneous adipose (SWAT), and the development of metabolic disease, but the precise mechanisms by which sex hormones influence adipose function and distribution remain unclear. We have previously shown that there is an obesity-specific mechanism of adipogenesis that drives adipocyte hyperplasia in a sex-specific pattern. Estrogen plays a role in this process, where exogenous estrogen drives a female-like patterning (both VWAT and SWAT) of adipocyte hyperplasia in male mice, while the absence of systemic estrogen in female mice results in male-like patterning (VWAT only response). Our preliminary data indicates that in the absence of systemic estrogen, estrogen signaling still plays a direct role in VWAT adipocyte hyperplasia at the onset of obesity. We show here that it is VWAT endothelial cells that express aromatase and thereby produce the estrogen required for adipocyte hyperplasia in males and ovariectomized females. We propose that aromatase expression in VWAT endothelium is controlled by glucocorticoids, linking the VWAT-specific actions of estrogen to the hypothalamic-pituitary-adrenal (HPA) axis. Based on our preliminary data, we hypothesize that estrogen and glucocorticoids participate in an endothelial cell-adipocyte precursor axis that regulates obesogenic adipogenesis, thereby influencing distribution of WAT and impacting metabolic disease. Here we will establish the role of adipose- produced estrogen in obesity and metabolic disease, determine the mechanisms that regulate aromatase in VWAT endothelial cells and define the molecular mechanisms of that regulate estrogen action in adipocyte precursors.