Hormonal regulation of hepatic IGF-I and IGF-II gene expression in the Marine TeleostSparus aurata

Carnevali, Oliana; Cardinali, Marco; Maradonna, Francesca; Parisi, M. de las Nieves; Olivotto, Ike; Polzonetti-Magni, A.M.; Mosconi, Gilberto; Funkenstein, Bruria

doi:10.1002/mrd.20122

Cited by 62 publications

(32 citation statements)

References 56 publications

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“…In the present study, the expression of both sbGHR1 and sbGHR2 was found to be decreased by estradiol treatment in black seabream. This decreased receptor expression in the seabream liver by estradiol in fact provides an explanation to a recent report that estradiol decreases GH-stimulated expression of IGF-I mRNA in the seabream liver (Carnevali et al 2005). In mammals, rather diverse observations on estradiol regulated GHR expression have been reported.…”

Section: Discussionmentioning

confidence: 57%

The co-existence of two growth hormone receptors in teleost fish and their differential signal transduction, tissue distribution and hormonal regulation of expression in seabream

Jiao

Huang²,

Chan³

et al. 2006

Journal of Molecular Endocrinology

151

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Two genomic contigs of putative growth hormone receptors (GHRs) were identified in fugu and zebrafish genomes by in silico analysis, suggesting the presence of two GHR subtypes in a single teleost species. We have tested this hypothesis by cloning the full-length cDNA sequence of a second GHR subtype from the black seabream in which the first GHR subtype had been previously reported by us. In addition, we had also cloned the sequences of both GHR subtypes from two other fish species, namely the Southern catfish and the Nile tilapia. Phylogenetic analysis of known GHR sequences from various vertebrates revealed that fish GHRs cluster into two distinct clades, viz. GHR1 and GHR2. One clade (GHR1), containing 6 to 7 extracellular cysteine residues, is structurally more akin to the non-teleost GHRs. The other clade (GHR2), containing only 4 to 5 extracellular cysteine residues, is unique to teleosts and is structurally more divergent from the non-teleost GHRs. In addition, we had examined the biological activities of both GHR subtypes from seabream using a number of reporter transcription assays in cultured eukaryotic cells and demonstrated that both of them were able to activate the Spi 2·1 and -casein promoters upon receptor stimulation in a ligand specific manner. In contrast, only GHR1 but not GHR2 in seabream could trigger the c-fos promoter activity, indicating that the two GHR subtypes possess some differences in their signal transduction mechanisms. Also, the expression of GHR2 is significantly higher than GHR1 in many tissues of the seabream including the gonad, kidney, muscle, pituitary and spleen. In vivo hormone treatment data indicated that cortisol upregulated hepatic GHR1 expression in seabream but not GHR2, whereas testosterone decreased hepatic GHR2 expression but not GHR1. On the other hand, hepatic expression of both GHR1 and GHR2 in seabream was decreased by estradiol treatment.

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Section: Discussionmentioning

confidence: 57%

The co-existence of two growth hormone receptors in teleost fish and their differential signal transduction, tissue distribution and hormonal regulation of expression in seabream

Jiao

Huang²,

Chan³

et al. 2006

Journal of Molecular Endocrinology

151

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“…However, even without assuming a causative role of the EE 2 -induced activation and upregulation of the ER pathway, our results suggest that administration of EE 2 during early development exerts a long-term suppressive effect on hepatic IGF-I expression and synthesis. Previous in vivo and in vitro studies in adults of different fish species also reported an estrogen-associated decrease in hepatic IGF-I mRNA (Riley et al 2004, Carnevali et al 2005, Filby et al 2006 or in serum IGF-I (Arsenault et al 2004, McCormick et al 2005.…”

Section: Discussionmentioning

confidence: 85%

“…Thus, there is a rising interest in the significance of IGF-I in fish development, growth, and reproduction. In this respect, some evidence has been presented (Riley et al 2004, Carnevali et al 2005, McCormick et al 2005) that estrogens may acutely influence synthesis and/or release of IGF-I from adult fish liver. Very recently, the influence of exposure to estrogen (E 2 ) on several genes, including IGF-I, has been investigated in adults of the fathead minnow (Filby et al 2006).…”

Section: Introductionmentioning

confidence: 99%

Ethinylestradiol differentially interferes with IGF-I in liver and extrahepatic sites during development of male and female bony fish

Shved

Berishvili

D'Cotta

et al. 2007

Journal of Endocrinology

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Growth and sexual development are closely interlinked in fish; however, no reports exist on potential effects of estrogen on the GH/IGF-I-axis in developing fish. We investigate whether estrogen exposure during early development affects growth and the IGF-I system, both at the systemic and tissue level. Tilapia were fed from 10 to 40 days post fertilization (DPF) with 17a-ethinylestradiol (EE 2 ). At 50, 75, 90, and 165 DPF, length, weight, sex ratio, serum IGF-I (RIA), pituitary GH mRNA and IGF-I, and estrogen receptor a (ERa) mRNA in liver, gonads, brain, and gills (real-time PCR) were determined and the results correlated to those of in situ hybridization for IGF-I. Developmental exposure to EE 2 had persistent effects on sex ratio and growth. Serum IGF-I, hepatic IGF-I mRNA, and the number of IGF-I mRNA-containing hepatocytes were significantly decreased at 75 DPF, while liver ERa mRNA was significantly induced. At 75 DPF, a transient decline of IGF-I mRNA and a largely reduced number of IGF-I mRNA-containing neurons were observed in the female brain. In both sexes, pituitary GH mRNA was significantly suppressed. A transient downregulation of IGF-I mRNA occurred in ovaries (75 DPF) and testes (90 DPF). In agreement, in situ hybridization revealed less IGF-I mRNA signals in granulosa and germ cells. Our results show for the first time that developmental estrogen treatment impairs GH/IGF-I expression in fish, and that the effects persist. These long-lasting effects both seem to be exerted indirectly via inhibition of pituitary GH and directly by suppression of local IGF-I in organ-specific cells.

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“…Recent studies show that teleost fishes including salmonids, sea bream, carp, catfish, eels, rabbitfish, sea bass, and hybrid striped bass, as well as the dogfish, an elasmobranch, differ from mammals in that liver igf2 gene expression and plasma Igf2 levels are stimulated by GH and respond to metabolic status (Shamblott et al 1995, Tse et al 2002, Vong et al 2003a, Peterson et al 2004, Carnevali et al 2005, Gabillard et al 2006, Wilkinson et al 2006, Ayson et al 2007, Terova et al 2007, Gahr et al 2008, Moriyama et al 2008a, b, Picha et al 2008b, Ponce et al 2008, Devlin et al 2009, Peterson & Waldbieser 2009, Eppler et al 2010, Pierce et al 2010. In primary cultured coho salmon hepatocytes, insulin directly increased igf2 mRNA, and strongly increased the response of igf2 mRNA to GH, but suppressed the response of igf1 mRNA to GH (Pierce et al 2005(Pierce et al , 2010.…”

Section: Introductionmentioning

confidence: 99%

Differential regulation of Igf1 and Igf2 mRNA levels in tilapia hepatocytes: effects of insulin and cortisol on GH sensitivity

Pierce

Breves²,

Moriyama³

et al. 2011

Journal of Endocrinology

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Igf1 and Igf2 stimulate growth and development of vertebrates. In mammals, liver-derived endocrine Igf1 mediates the growth promoting effects of GH during postnatal life, whereas Igf2 stimulates placental and fetal growth and is not regulated by GH. Insulin enhances Igf1 production by the mammalian liver directly, and by increasing hepatocyte sensitivity to GH. We examined the regulation of igf1 and igf2 mRNA levels by GH, insulin, and cortisol, and the effects of insulin and cortisol on GH sensitivity in primary cultured hepatocytes of tilapia, a cichlid teleost. GH increased mRNA levels of both igf1 and igf2 in a concentration-related and biphasic manner over the physiological range, with a greater effect on igf2 mRNA level. Insulin increased basal igf2 mRNA level, and strongly increased GH-stimulated igf2 mRNA level, but slightly reduced basal igf1 mRNA level and did not affect GH-stimulated igf1 mRNA level. Cortisol inhibited GH stimulation of igf1, but increased GH stimulation of igf2 mRNA level. The synergistic effect of insulin and GH on igf2 mRNA level was confirmed in vivo. These results indicate that insulin and cortisol differentially modulate the response of igf1 and igf2 mRNA to GH in tilapia hepatocytes, and suggest that the regulation of liver Igf2 production differs between fish and mammals. Regulation of liver Igf2 production in fish appears to be similar to regulation of liver Igf1 production in mammals.

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Hormonal regulation of hepatic IGF-I and IGF-II gene expression in the Marine TeleostSparus aurata

Cited by 62 publications

References 56 publications

The co-existence of two growth hormone receptors in teleost fish and their differential signal transduction, tissue distribution and hormonal regulation of expression in seabream

The co-existence of two growth hormone receptors in teleost fish and their differential signal transduction, tissue distribution and hormonal regulation of expression in seabream

Ethinylestradiol differentially interferes with IGF-I in liver and extrahepatic sites during development of male and female bony fish

Differential regulation of Igf1 and Igf2 mRNA levels in tilapia hepatocytes: effects of insulin and cortisol on GH sensitivity

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