Altered protein expression and phosphorylation from retroperitoneal adipose tissue of ovariectomy rats.xlsx

Menopause is often accompanied by visceral obesity. With the aim of exploring the consequences of ovarian failure on visceral fat, we evaluated the effects of ovariectomy and estrogen replacement on the proteome/phosphoproteome and on the fatty acids profile of the retroperitoneal adipose depot (RAT) of rats. Eighteen three months old female Wistar rats were either ovariectomized or sham-operated and fed with standard chow for three months. A sub-group of ovariectomized rats received estradiol replacement. RAT samples were analyzed using data-independent acquisitions LC-MS/MS and pathway analysis was performed with the differentially expressed/phosphorylated proteins. RAT lipid profile was analyzed by gas chromatography. Ovariectomy induced high adiposity and insulin resistance and promoted alterations in protein expression and phosphorylation. Pathway analysis showed that 5 pathways were significantly affected by ovariectomy, namely metabolism of lipids (included fatty acid metabolism and mitochondrial fatty acid β-oxidation), fatty acyl-CoA biosynthesis, innate immune system (included neutrophil degranulation), metabolism of vitamins and cofactors, and integration of energy metabolism (included ChREBP activates metabolic gene expression). Lipid profile analysis showed increased palmitic and palmitoleic acids content. The analysis of the data indicated that ovariectomy favored lipogenesis while it impaired fatty acids oxidation, and induced a pro-inflammatory state in the visceral adipose tissue. These effects are consistent with the findings of high adiposity, hyperleptinemia, and impaired insulin sensitivity. The observed alterations were partially attenuated by estradiol replacement. The data point to a role of disrupted lipid metabolism in adipose tissue in the genesis of obesity after menopause.

绝经常伴随内脏型肥胖。本研究旨在探讨卵巢功能衰竭对内脏脂肪的影响，评估卵巢切除术与雌激素替代疗法对大鼠腹膜后脂肪垫（retroperitoneal adipose depot, RAT）的蛋白质组/磷酸化蛋白质组以及脂肪酸谱的作用。选取18只3月龄雌性Wistar大鼠，随机分为卵巢切除术组与假手术组，均采用标准饲料喂养3个月；其中卵巢切除术组的亚组大鼠接受雌二醇替代治疗。采用数据非依赖性采集液相色谱-串联质谱（data-independent acquisitions LC-MS/MS）对RAT样本进行分析，并对差异表达/磷酸化蛋白质进行通路富集分析；采用气相色谱法分析RAT的脂质谱。卵巢切除术可诱导大鼠出现高肥胖症与胰岛素抵抗，并促进蛋白质表达与磷酸化水平发生改变。通路富集分析显示，卵巢切除术显著影响了5条通路，分别为脂质代谢（涵盖脂肪酸代谢与线粒体脂肪酸β-氧化）、脂酰辅酶A生物合成、先天免疫系统（涵盖中性粒细胞脱颗粒）、维生素与辅因子代谢，以及能量代谢整合（涵盖碳水化合物反应元件结合蛋白（ChREBP）激活代谢基因表达）。脂质谱分析结果显示，棕榈酸与棕榈油酸的含量升高。数据分析表明，卵巢切除术可促进脂肪生成，同时削弱脂肪酸氧化过程，并在内脏脂肪组织中诱导促炎状态。上述效应与高肥胖症、高瘦素血症及胰岛素敏感性受损的研究结果相符。雌二醇替代治疗可部分缓解上述观察到的异常改变。本研究数据表明，脂肪组织脂质代谢紊乱在绝经后肥胖的发生发展中发挥了一定作用。