CB1R拮抗剂可能通过上调肝脏脂联素受体来增加高脂喂养犬的肝脏胰岛素清除率。
CB1R antagonist increases hepatic insulin clearance in fat-fed dogs likely via upregulation of liver adiponectin receptors.
作者信息
Kabir Morvarid, Iyer Malini S, Richey Joyce M, Woolcott Orison O, Asare Bediako Isaac, Wu Qiang, Kim Stella P, Stefanovski Darko, Kolka Cathryn M, Hsu Isabel R, Catalano Karyn J, Chiu Jenny D, Ionut Viorica, Bergman Richard N
机构信息
Cedars-Sinai Diabetes and Obesity Research Institute, Los Angeles, California; and
Cedars-Sinai Diabetes and Obesity Research Institute, Los Angeles, California; and.
出版信息
Am J Physiol Endocrinol Metab. 2015 Oct 15;309(8):E747-58. doi: 10.1152/ajpendo.00196.2015. Epub 2015 Aug 25.
The improvement of hepatic insulin sensitivity by the cannabinoid receptor 1 (CB1R) antagonist rimonabant (RIM) has been recently been reported to be due to upregulation of adiponectin. Several studies demonstrated that improvement in insulin clearance accompanies the enhancement of hepatic insulin sensitivity. However, the effects of RIM on hepatic insulin clearance (HIC) have not been fully explored. The aim of this study was to explore the molecular mechanism(s) by which RIM affects HIC, specifically to determine whether upregulation of liver adiponectin receptors (ADRs) and other key genes regulated by adiponectin mediate the effects. To induce insulin resistance in skeletal muscle and liver, dogs were fed a hypercaloric high-fat diet (HFD) for 6 wk. Thereafter, while still maintained on a HFD, animals received RIM (HFD+RIM; n = 11) or placebo (HFD+PL; n = 9) for an additional 16 wk. HIC, calculated as the metabolic clearance rate (MCR), was estimated from the euglycemic-hyperinsulinemic clamp. The HFD+PL group showed a decrease in MCR; in contrast, the HFD+RIM group increased MCR. Consistently, the expression of genes involved in HIC, CEACAM-1 and IDE, as well as gene expression of liver ADRs, were increased in the HFD+RIM group, but not in the HFD+PL group. We also found a positive correlation between CEACAM-1 and the insulin-degrading enzyme IDE with ADRs. Interestingly, expression of liver genes regulated by adiponectin and involved in lipid oxidation were increased in the HFD+RIM group. We conclude that in fat-fed dogs RIM enhances HIC, which appears to be linked to an upregulation of the adiponectin pathway.
近期有报道称,大麻素受体1(CB1R)拮抗剂利莫那班(RIM)可通过上调脂联素改善肝脏胰岛素敏感性。多项研究表明,胰岛素清除率的提高与肝脏胰岛素敏感性的增强相伴。然而,RIM对肝脏胰岛素清除率(HIC)的影响尚未得到充分研究。本研究的目的是探讨RIM影响HIC的分子机制,特别是确定肝脏脂联素受体(ADR)和其他受脂联素调节的关键基因的上调是否介导了这些作用。为诱导骨骼肌和肝脏的胰岛素抵抗,给犬喂食高热量高脂肪饮食(HFD)6周。此后,在继续给予HFD的同时,动物接受RIM(HFD+RIM;n = 11)或安慰剂(HFD+PL;n = 9),持续16周。通过正常血糖-高胰岛素钳夹技术估算以代谢清除率(MCR)计算的HIC。HFD+PL组MCR降低;相比之下,HFD+RIM组MCR升高。一致地,HFD+RIM组中涉及HIC的基因CEACAM-1和IDE的表达以及肝脏ADR的基因表达增加,而HFD+PL组未增加。我们还发现CEACAM-1和胰岛素降解酶IDE与ADR之间呈正相关。有趣的是,HFD+RIM组中受脂联素调节且参与脂质氧化的肝脏基因表达增加。我们得出结论,在喂食脂肪的犬中,RIM增强HIC,这似乎与脂联素途径的上调有关。