CCAAT/enhancer binding protein beta2 is involved in growth hormone-regulated insulin-like growth factor-II gene expression in the liver of rainbow trout (Oncorhynchus mykiss).

نویسندگان

  • Jay H Lo
  • Thomas T Chen
چکیده

Previously, we showed that levels of different CCAAT/enhancer binding protein (C/EBP) mRNAs in the liver of rainbow trout were modulated by GH and suggested that C/EBPs might be involved in GH-induced IGF-II gene expression. As a step toward further investigation, we have developed monospecific polyclonal antibodies to detect rainbow trout C/EBPalpha, -beta1, -beta2, and -delta2 isoform proteins. Injection of GH into adult rainbow trout resulted in a significant increase of C/EBPbeta1, C/EBPbeta2, and C/EBPdelta2 proteins in the liver. Chromatin immunoprecipitation analysis revealed that C/EBPbeta2 binds to multiple sites at the 5' promoter/regulatory region, introns, and the 3' untranslated region of the IGF-II gene. GH treatment reduced C/EBPbeta2 binding to several of these regions at 6 h after injection. The decreased occupancy of C/EBPbeta2 coincided well with an increase of histone H4 acetylation at the proximal promoter and elevation of the IGF-II mRNA level. Immunoblotting analysis showed that C/EBPbeta2 existed predominately as a truncated form in the liver, and cotransfection analysis further showed that the truncated C/EBPbeta2 acted as a negative regulator on IGF-II proximal promoter. GH treatment caused deacetylation of C/EBPbeta2 in the liver. In addition, we observed a GH-dependent interaction of C/EBPbeta2 with a complex involving histone H1. All together, these results suggest that C/EBPbeta2 was regulated at multiple levels by GH, and C/EBPbeta2 may play a suppressive role in mediating GH-induced IGF-II expression in the liver of rainbow trout.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Effects of three beta adrenergic receptor agonists on growth performance, blood biochemical parameters, fatty acids composition and carnitine palmitoyltransferase I gene expression of rainbow trout, Oncorhynchus mykiss

Different beta 1 and 2 adrenergic receptors agonists might have various biological and physiological effects on fish species. An experiment was designed to study the effects of feeding ractopamine, terbutaline and metaproterenol; as beta1, beta2 and less selective beta2 adrenergic receptor agonists, respectively; on body weight gain, feed conversion rate, concentration of biochemical parameters...

متن کامل

Effects of three beta adrenergic receptor agonists on growth performance, blood biochemical parameters, fatty acids composition and carnitine palmitoyltransferase I gene expression of rainbow trout Oncorhynchus mykiss

Different beta 1 and 2 adrenergic receptor agonists may be various biological and physiological effects on fish species. An experiment was designed to study the effects of feeding ractopamine, terbutaline and metaproterenol; as beta1, beta2 and less selective beta 2 adrenergic receptor agonists, respectively; on body weight gain, feed conversion ratio, concentration of biochemical parameters in...

متن کامل

Comparison of growth parameters, cortisol and muscle gene expression of rainbow trout reared in an open and water reuse system

Fish farming in recirculating aquaculture systems (RAS) has been expanding in the recent years, but the effects of water reuse are not well known. The aim of the present study was to compare the growth parameters, stress response and muscle stress- and growth- related gene expression of rainbow trout (Oncorhynchus mykiss) in open system (OS) versus water reuse system (WRS). For this purpose, yo...

متن کامل

Effects of short-term growth hormone treatment on liver and muscle transcriptomes in rainbow trout (Oncorhynchus mykiss).

Although studies have established that exogenous growth hormone (GH) treatment stimulates growth in fish, its effects on target tissue gene expression are not well characterized. We assessed the effects of Posilac (Monsanto, St. Louis, MO), a recombinant bovine GH, on tissue transcript levels in rainbow trout selected from two high-growth rate and two low-growth rate families. Transcript abunda...

متن کامل

Regulation of the somatotropic axis by dietary factors in rainbow trout (Oncorhynchus mykiss).

The activity of the somatotropic axis was analysed in juvenile rainbow trout (Oncorhynchus mykiss) fed either a fishmeal-based diet (FM) or graded levels of plant proteins to replace 50% (PP50 diet), 75% (PP75 diet) or 100% (PP100 diet) of the fishmeal protein. For this purpose, partial cloning and sequencing of the gene encoding rainbow trout growth hormone receptor (GHR) was first accomplishe...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Endocrinology

دوره 151 5  شماره 

صفحات  -

تاریخ انتشار 2010