Department of Cellular and Physiological Sciences, Diabetes Research Group, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada.
Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada.
FASEB J. 2018 Mar;32(3):1196-1206. doi: 10.1096/fj.201700518R. Epub 2018 Jan 3.
Excess circulating insulin is associated with obesity in humans and in animal models. However, the physiologic causality of hyperinsulinemia in adult obesity has rightfully been questioned because of the absence of clear evidence that weight loss can be induced by acutely reversing diet-induced hyperinsulinemia. Herein, we describe the consequences of inducible, partial insulin gene deletion in a mouse model in which animals have already been made obese by consuming a high-fat diet. A modest reduction in insulin production/secretion was sufficient to cause significant weight loss within 5 wk, with a specific effect on visceral adipose tissue. This result was associated with a reduction in the protein abundance of the lipodystrophy gene polymerase I and transcript release factor ( Ptrf; Cavin) in gonadal adipose tissue. RNAseq analysis showed that reduced insulin and weight loss also associated with a signature of reduced innate immunity. This study demonstrates that changes in circulating insulin that are too fine to adversely affect glucose homeostasis nonetheless exert control over adiposity.-Page, M. M., Skovsø, S., Cen, H., Chiu, A. P., Dionne, D. A., Hutchinson, D. F., Lim, G. E., Szabat, M., Flibotte, S., Sinha, S., Nislow, C., Rodrigues, B., Johnson, J. D. Reducing insulin via conditional partial gene ablation in adults reverses diet-induced weight gain.
循环胰岛素过多与人类和动物模型中的肥胖有关。然而,由于没有明确的证据表明可以通过急性逆转饮食诱导的高胰岛素血症来诱导体重减轻,因此成人肥胖中高胰岛素血症的生理因果关系受到了质疑。在此,我们描述了在一种小鼠模型中,胰岛素基因的诱导性部分缺失的后果,在该模型中,动物通过食用高脂肪饮食已经肥胖。胰岛素产生/分泌的适度减少足以在 5 周内导致明显的体重减轻,对内脏脂肪组织有特定的影响。这一结果与性腺脂肪组织中脂肪营养不良基因聚合酶 I 和转录释放因子(Ptrf;Cavin)的蛋白丰度降低有关。RNAseq 分析表明,胰岛素减少和体重减轻也与先天免疫减少的特征有关。这项研究表明,循环胰岛素的变化即使细微到不会对葡萄糖稳态产生不利影响,但仍能控制肥胖。