Orexin-A stimulates the expression of GLUT4 in a glucose dependent manner in the liver of orange-spotted grouper (Epinephelus coioides)

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• 作者：Cong Zhang ; Caiyun Sun ; Bin Wang ; Peipei Yan ; Amin Wu ; Guokun Yang ; Wensheng Li ; ^{lsslws@mail.sysu.edu.cn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：OXA ; Orexin-A ; OXR ; Orexin receptor ; GLUT4 ; Glucose transporter 4 ; I.P. ; Intraperitoneal ; MAPK ; Mitogen-activated protein kinase ; JNK ; Jun N-terminal kinase ; ERK1/2 ; Extracellular signal-regulated kinase ; FBS ; Fetal bovine serum ; BSA ; Bovine serum albumin ; SB334867 ; 1-(2-methylbenzoxazol-6-yl)-3-[1 ; 5]naphthyridin-4-yl urea ; U0126 ; 1 ; 4-diamino-2 ; 3-dicyano-1 ; 4-bis(2-aminophenylthio) butadiene ; SP600125 ; 2H-Dibenzo[cd ; g]indazol-6-one ; SB203580 ; 4-[4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-1H-im
• 刊名：Comparative Biochemistry and Physiology - Part A: Molecular & Integrative Physiology
• 出版年：2016
• 出版时间：September 2016
• 年：2016
• 卷：199
• 期：Complete
• 页码：95-104
• 全文大小：1203 K

文摘

Orexins are hypothalamic neuropeptides involved in the central regulation of feeding behavior, sleep-wake cycle and other physiological functions. Orexin-A can regulate energy metabolism and increase glucose uptake, suggesting a role in glucose metabolism. In this study, we investigated the effects of orexin-A on GLUT4 mRNA and protein levels and the intracellular signaling mechanisms mediating orexin-A activity in the hepatocytes of grouper. Our results demonstrate that intraperitoneal injection of orexin-A increased the expression of GLUT4 in the liver, and this effect was significantly enhanced by co-injection of glucose. Treatment of primary cultured hepatocytes with either orexin-A or glucose alone had no effect on the expression of GLUT4, while co-treatment with orexin-A and glucose significantly increased the expression of GLUT4. This stimulatory effect was partially blocked by inhibitors to ERK1/2, JNK or p38 MAPK and was further blocked by an orexin receptor antagonist, which indicates that orexin-A could stimulate the expression of GLUT4 in a glucose dependent manner in primary hepatocytes via ERK1/2, JNK and p38 signaling. Our results suggest that orexin-A could play a pivotal role in stimulating glucose utilization in grouper, for a long-term goal, which might be useful in reducing costs in the aquaculture industry.