Gomori A, Ishihara A, Ito M, Matsushita H, Ito M, Mashiko S, Iwaasa H, Matsuda M, Bednarek M A, Qian S, Macneil D J, Kanatani A
Department of Pharmacology, Tsukuba Research Institute, Banyu Pharmaceutical Co. Ltd, Tsukuba, Japan.
Br J Pharmacol. 2007 Jul;151(6):900-8. doi: 10.1038/sj.bjp.0707292. Epub 2007 May 21.
Melanin-concentrating hormone (MCH) is a cyclic orexigenic neuropeptide predominantly expressed in the lateral hypothalamus. We investigated the roles of MCH1 receptor signalling in ovariectomy (OVX)-induced obesity in female C57BL/6J mice, an animal model of postmenopausal obesity.
The effects of blocking signalling via the MCH1 receptor on OVX-induced obesity was investigated by using Mch1r deficient (KO) mice and chronic treatment with a selective MCH1 receptor antagonist.
OVX induced body weight gain and increases in the weight of visceral fat and of liver; these effects were attenuated following OVX in Mch1r KO mice. OVX-induced triglyceride (TG) accumulation and elevated expression of lipogenic genes were significantly ameliorated in the liver of Mch1r KO mice. In agreement with these results, chronic i.c.v. infusion of a selective MCH1 receptor antagonist significantly reduced body weight gain, visceral fat and liver weights in OVX mice, and hepatic TG contents and lipogenic gene expression levels were normalized.
Our results indicate that MCH1 receptor signalling is involved in the development of fatty liver, as well as obesity, in OVX mice, and suggest a therapeutic potential for MCH1 receptor antagonists in the treatment of obesity and fatty liver.
促黑素(MCH)是一种主要在下丘脑外侧表达的环型促食欲神经肽。我们研究了MCH1受体信号传导在去卵巢(OVX)诱导的雌性C57BL/6J小鼠肥胖中的作用,该小鼠是绝经后肥胖的动物模型。
通过使用Mch1r基因缺陷(KO)小鼠以及用选择性MCH1受体拮抗剂进行长期治疗,研究阻断MCH1受体信号传导对OVX诱导的肥胖的影响。
OVX导致体重增加,内脏脂肪和肝脏重量增加;在Mch1r KO小鼠中,OVX后的这些影响减弱。Mch1r KO小鼠肝脏中OVX诱导的甘油三酯(TG)积累和脂肪生成基因表达升高得到显著改善。与这些结果一致,慢性脑室内注射选择性MCH1受体拮抗剂可显著降低OVX小鼠的体重增加、内脏脂肪和肝脏重量,肝脏TG含量和脂肪生成基因表达水平恢复正常。
我们的结果表明,MCH1受体信号传导参与了OVX小鼠脂肪肝以及肥胖的发生发展,并提示MCH1受体拮抗剂在治疗肥胖和脂肪肝方面具有治疗潜力。