Ghrelin modulates fatty acid synthase and related transcription factor mRNA levels in a tissue-specific manner in neonatal broiler chicks
Ghrelin modulates fatty acid synthase and related transcription factor mRNA levels in a tissue-specific manner in neonatal broiler chicks
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DOI：
10.1016/j.peptides.2009.04.015
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发表时间：
2009-07-01
期刊：
影响因子：
3
通讯作者：
Dridi, Sami
中科院分区：
文献类型：
--
作者：
Buyse, Johan;Janssen, Sara;Dridi, Sami
生长激素（GH）促分泌素受体ghrelin的内源性配体是由哺乳动物的胃分泌的肽，并且刺激食物摄取和增强肥胖。在鸟类中，ghrelin主要由前胃产生，但减少食物摄入，而其对不同组织中脂肪生成的影响尚不清楚。因此，我们研究了2.8 μ g（每只鸡1 nmol）重组鸡生长激素释放肽在新生肉鸡中的单次静脉注射的效果。除了食物摄入量和血浆皮质酮水平，关键脂肪生成酶脂肪酸合成酶（FAS）及其相关转录因子固醇调节元件结合蛋白-1（SREBP-1）和过氧化物酶体增殖物激活受体-γ（PPAR γ）的mRNA水平在间脑，肝脏和股四头肌注射前，15，30和60分钟后进行了测定。鸡生长素释放肽给药引起食物摄入的显著短期（< 30分钟）减少和血浆皮质酮水平的显著升高。在间脑，FAS，SREBP-1和PPAR γ mRNA水平显着增加后15分钟内注射ghrelin。这些观察结果表明，中央脂肪酸代谢参与饥饿素的厌食作用。与此相反，FAS和两个转录因子的肝mRNA水平显着减少后30分钟内注射ghrelin。在肌肉中，FAS和转录因子基因表达非常低，不受ghrelin的影响。总体而言，我们的研究结果表明，生长激素释放肽对FAS和转录因子mRNA量具有相反的影响，在鸡的间脑中水平增加（中枢厌食作用），肝脏中水平降低（外周抗脂肪生成作用）。(C)2009 Elsevier Inc. All rights reserved.
The endogenous ligand for the growth hormone (GH) secretagogue receptor ghrelin is a peptide secreted by the stomach of mammals and stimulates food intake and enhances adiposity. In avian species, ghrelin is mainly produced by the proventriculus but reduces food intake whereas its effect on lipogenesis in different tissues is unknown. We therefore investigated the effects of a single intravenous injection of 2.8 mu g (1 nmol per chick) recombinant chicken ghrelin in neonatal broiler chicks. Besides food intake and plasma corticosterone levels, mRNA levels of the key lipogenic enzyme fatty acid synthase (FAS) and its related transcription factors sterol regulatory element binding protein-1 (SREBP-1) and peroxisome proliferator-activated receptor-gamma (PPAR gamma) were determined in diencephalon, liver and quadriceps femoris muscle before, and 15, 30, and 60 min after injection. Chicken ghrelin administration induced a significant short-term (< 30 min) reduction in food intake and markedly elevated plasma corticosterone levels. In diencephalon, FAS, SREBP-1 and PPAR gamma mRNA levels were significantly increased within 15 min after ghrelin injection. These observations suggest that central fatty acid metabolism is involved in the anorectic effects of ghrelin. In contrast, hepatic mRNA levels of FAS and both transcription factors were significantly reduced within 30 min after ghrelin injection. In muscle, FAS and transcription factor gene expression was very low and not affected by ghrelin. Overall, our results indicate that ghrelin has opposite effects on FAS and transcription factor mRNA amounts with increased levels in diencephalon (central anorectic effect) and decreased levels in liver (peripheral anti-lipogenic effect) in chickens. (C) 2009 Elsevier Inc. All rights reserved.