Keeley Tyler, Kirov Aleksandr, Koh Woon Yuen, Demambro Victoria, Bergquist Ivy, Cotter Jessica, Caradonna Peter, Siviski Matthew E, Best Bradley, Henderson Terry, Rosen Clifford J, Liaw Lucy, Prudovsky Igor, Small Deena J
Department of Chemistry and Physics, College of Arts and Sciences, University of New England, Biddeford, Maine.
Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine.
Physiol Rep. 2019 Apr;7(7):e14034. doi: 10.14814/phy2.14034.
Overdevelopment of visceral adipose is positively correlated with the etiology of obesity-associated pathologies including cardiovascular disease and insulin resistance. However, identification of genetic, molecular, and physiological factors regulating adipose development and function in response to nutritional stress is incomplete. Fibroblast Growth Factor 1 (FGF1) is a cytokine expressed and released by both adipocytes and endothelial cells under hypoxia, thermal, and oxidative stress. Expression of Fibroblast Growth Factor 1 (FGF1) in adipose is required for normal depot development and remodeling. Loss of FGF1 leads to deleterious changes in adipose morphology, metabolism, and insulin resistance. Conversely, diabetic and obese mice injected with recombinant FGF1 display improvements in insulin sensitivity and a reduction in adiposity. We report in this novel, in vivo study that transgenic mice expressing an endothelial-specific FGF1 transgene (FGF1-Tek) are resistant to high-fat diet-induced abdominal adipose accretion and are more glucose-tolerant than wild-type control animals. Metabolic chamber analyses indicate that suppression of the development of visceral adiposity and insulin resistance was not associated with alterations in appetite or resting metabolic rate in the FGF1-Tek strain. Instead, FGF1-Tek mice display increased locomotor activity that likely promotes the utilization of dietary fatty acids before they can accumulate in adipose and liver. This study provides insight into the impact that genetic differences dictating the production of FGF1 has on the risk for developing obesity-related metabolic disease in response to nutritional stress.
内脏脂肪过度发育与包括心血管疾病和胰岛素抵抗在内的肥胖相关病理的病因呈正相关。然而,对于在营养应激下调节脂肪发育和功能的遗传、分子和生理因素的识别尚不完整。成纤维细胞生长因子1(FGF1)是一种在缺氧、热应激和氧化应激下由脂肪细胞和内皮细胞表达并释放的细胞因子。脂肪组织中FGF1的表达是正常脂肪库发育和重塑所必需的。FGF1的缺失会导致脂肪形态、代谢和胰岛素抵抗发生有害变化。相反,注射重组FGF1的糖尿病和肥胖小鼠的胰岛素敏感性得到改善,肥胖程度降低。我们在这项新的体内研究中报告,表达内皮特异性FGF1转基因(FGF1-Tek)的转基因小鼠对高脂饮食诱导的腹部脂肪堆积具有抗性,并且比野生型对照动物更耐葡萄糖。代谢室分析表明,FGF1-Tek品系中内脏肥胖和胰岛素抵抗的发展受到抑制与食欲或静息代谢率的改变无关。相反,FGF1-Tek小鼠表现出运动活性增加,这可能促进膳食脂肪酸在积聚于脂肪和肝脏之前被利用。这项研究深入了解了决定FGF1产生的遗传差异对营养应激下发生肥胖相关代谢疾病风险的影响。