Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston MA 02215, USA.
Department of Biochemistry, Weill Cornell Medical College, New York, NY 10065, USA.
Cell Rep. 2017 Oct 24;21(4):1021-1035. doi: 10.1016/j.celrep.2017.09.091.
Lower adipose-ChREBP and de novo lipogenesis (DNL) are associated with insulin resistance in humans. Here, we generated adipose-specific ChREBP knockout (AdChREBP KO) mice with negligible sucrose-induced DNL in adipose tissue (AT). Chow-fed AdChREBP KO mice are insulin resistant with impaired insulin action in the liver, muscle, and AT and increased AT inflammation. HFD-fed AdChREBP KO mice are also more insulin resistant than controls. Surprisingly, adipocytes lacking ChREBP display a cell-autonomous reduction in insulin-stimulated glucose transport that is mediated by impaired Glut4 translocation and exocytosis, not lower Glut4 levels. AdChREBP KO mice have lower levels of palmitic acid esters of hydroxy stearic acids (PAHSAs) in serum, and AT. 9-PAHSA supplementation completely rescues their insulin resistance and AT inflammation. 9-PAHSA also normalizes impaired glucose transport and Glut4 exocytosis in ChREBP KO adipocytes. Thus, loss of adipose-ChREBP is sufficient to cause insulin resistance, potentially by regulating AT glucose transport and flux through specific lipogenic pathways.
脂肪组织 ChREBP 和从头合成脂肪(DNL)与人类的胰岛素抵抗有关。在这里,我们生成了脂肪组织特异性 ChREBP 敲除(AdChREBP KO)小鼠,其脂肪组织中蔗糖诱导的 DNL 可忽略不计。正常饮食喂养的 AdChREBP KO 小鼠表现出胰岛素抵抗,肝脏、肌肉和脂肪组织的胰岛素作用受损,脂肪组织炎症增加。高脂肪饮食喂养的 AdChREBP KO 小鼠也比对照组更具胰岛素抵抗性。令人惊讶的是,缺乏 ChREBP 的脂肪细胞表现出胰岛素刺激的葡萄糖转运的细胞自主减少,这是由 Glut4 易位和胞吐作用受损介导的,而不是 Glut4 水平降低。AdChREBP KO 小鼠的血清和脂肪组织中棕榈酸羟基硬脂酸酯(PAHSAs)的水平较低。9-PAHSA 补充完全挽救了它们的胰岛素抵抗和脂肪组织炎症。9-PAHSA 还可使 ChREBP KO 脂肪细胞中受损的葡萄糖转运和 Glut4 胞吐作用正常化。因此,脂肪组织 ChREBP 的缺失足以导致胰岛素抵抗,可能是通过调节特定的脂肪生成途径来调节脂肪组织的葡萄糖转运和通量。