Regulation of growth hormone (GH) receptor (GHR1 and GHR2) mRNA level by GH and metabolic hormones in primary cultured tilapia hepatocytes
Regulation of growth hormone (GH) receptor (GHR1 and GHR2) mRNA level by GH and metabolic hormones in primary cultured tilapia hepatocytes
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DOI：
10.1016/j.ygcen.2012.07.010
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发表时间：
2012-10-01
影响因子：
2.7
通讯作者：
Grau, E. G.
中科院分区：
文献类型：
--
作者：
Pierce, A. L.;Breves, J. P.;Grau, E. G.
生长激素（GH）调节硬骨鱼的基本生理功能，包括生长、代谢和代谢调节。最近的研究已经确定了两个进化枝的推定受体生长激素（GHR 1进化枝和GHR 2进化枝）在鱼类，这两个都是高度表达的肝脏。此外，肝脏是GH通过内分泌IGFs合成代谢作用的重要靶点，肝脏对GH的敏感性受代谢激素调节。研究了生长激素、胰岛素、胰高血糖素、皮质醇和三碘甲状腺原氨酸对原代培养罗非鱼肝细胞GHR 1和GHR 2 mRNA水平的影响。生理浓度的GH强烈刺激GHR 2 mRNA水平（0.5-50 × 10（-9）M），但不影响GHR 1 mRNA水平。胰岛素抑制GH（10（-8）-10（-6）M）对GHR 2 mRNA水平的刺激。胰岛素增加基础GHR 1 mRNA水平（10（-8）-10（-6）M）。皮质醇增加基础GHR 2 mRNA水平（10（-7）-10（-6）M），但不影响GH刺激的GHR 2 mRNA水平。皮质醇增加基础GHR 1 mRNA水平（10（-9）-10（-6）M）。在超生理浓度（10（-6）M）下，胰高血糖素抑制GH刺激的GHR 2 mRNA水平，增加基础GHR 1 mRNA水平。单次注射GH（5 μ g/g）可增加肝脏GHR 2 mRNA水平，注射胰岛素（5 μ g/g）可降低基础水平和GH刺激的GHR 2 mRNA水平。而胰岛素和GH注射对肝脏GHR 1 mRNA水平影响不大。本研究表明，生长激素受体1和生长激素受体2基因表达的差异调节的生理水平的生长激素和胰岛素在罗非鱼原代肝细胞。(C)2012 Elsevier Inc. All rights reserved.
Growth hormone (GH) regulates essential physiological functions in teleost fishes, including growth, metabolism, and osmoregulation. Recent studies have identified two clades of putative receptors for GH (GHR1 clade and GHR2 clade) in fishes, both of which are highly expressed in the liver. Moreover, the liver is an important target for the anabolic effects of GH via endocrine IGFs, and liver sensitivity to GH is modulated by metabolic hormones. We investigated the effects of GH, insulin, glucagon, cortisol and triiodothyronine on GHR1 and GHR2 mRNA levels in primary cultured tilapia hepatocytes. Physiological concentrations of GH strongly stimulated GHR2 mRNA level (0.5-50 x 10(-9) M), but did not affect GHR1 mRNA level. Insulin suppressed stimulation of GHR2 mRNA level by GH (10(-8)-10(-6) M). Insulin increased basal GHR1 mRNA level (10(-8)-10(-6) M). Cortisol increased basal GHR2 mRNA level (10(-7)-10(-6) M), but did not consistently affect GH-stimulated GHR2 mRNA level. Cortisol increased basal GHR1 mRNA level (10(-9)-10(-6) M). Glucagon suppressed GH-stimulated GHR2 mRNA level and increased basal GHR1 mRNA level at a supraphysiological concentration (10(-6) M). A single injection of GH (5 mu g/g) increased liver GHR2 mRNA level, and insulin injection (5 mu g/g) decreased both basal and GH-stimulated GHR2 mRNA levels after 6 h. In contrast, insulin and GH injection had little effect on liver GHR1 mRNA level. This study shows that GHR1 and GHR2 gene expression are differentially regulated by physiological levels of GH and insulin in tilapia primary hepatocytes. (C) 2012 Elsevier Inc. All rights reserved.