scholarly journals Foreign GH gene expression in GH transgenic salmon

2002 ◽  
Vol 68 (sup2) ◽  
pp. 1071-1074 ◽  
Author(s):  
TSUKASA MORI ◽  
HIROYUKI NAGOYA ◽  
KAZUO ARAKI ◽  
ROBERT H. DEVLIN
Keyword(s):  
Gene Expression ◽  
Gh Gene ◽  
Transgenic Salmon

Gene transfer: potential to enhance the genome of Atlantic salmon for aquaculture

2004 ◽  
Vol 44 (11) ◽  
pp. 1095 ◽  
Author(s):  
G. L. Fletcher ◽  
M. A. Shears ◽  
E. S. Yaskowiak ◽  
M. J. King ◽  
S. V. Goddard
Keyword(s):  
Gene Transfer ◽  
Atlantic Salmon ◽  
Transgenic Fish ◽  
Single Copy ◽  
Environmental Safety ◽  
Chromosomal Dna ◽  
Regulatory Authorities ◽  
Gh Gene ◽  
The Usa ◽  
Transgenic Salmon

Over the past 20 years we have generated stable lines of transgenic Atlantic salmon possessing either antifreeze protein (AFP) genes or a salmon growth hormone (GH) gene construct. The AFP gene transfer studies were initiated in 1982. The AFP transgene integrated into salmon genomic DNA and AFP has been found in the blood of all 5 generations to date. However, AFP levels are low and a means to raise these levels needs to be developed. Our GH gene transfer studies were initiated in 1989. Evidence to date indicates that a single copy of the GH transgene integrated into chromosomal DNA and has been passed down in Mendelian fashion, along with its rapid growth phenotype, over 6 generations. Laboratory studies indicate that our GH transgene enhances growth rates with Atlantic salmon reaching market size (4–6 kg) a year earlier than non-transgenics cultured commercially in Atlantic Canada. This GH gene transfer technology was patented and licensed to Aqua Bounty Farms Inc., and the transgenic salmon are currently under review by various government regulatory authorities in the USA and Canada for use in commercial aquaculture ventures. Our experience with the regulatory authorities, the industry and the press indicates that the successful introduction of transgenic salmon into the aquaculture industry involves issues concerning not only science but also food safety, environmental safety, animal welfare and consumer acceptance. This communication centres on our experience with Atlantic salmon and outlines our plans and progress towards demonstrating the safety of transgenic fish to the consumer and to the environment.

Growth hormone in the nervous system: autocrine or paracrine roles in retinal function?

2003 ◽  
Vol 81 (4) ◽  
pp. 371-384 ◽  
Author(s):  
S Harvey ◽  
M Kakebeeke ◽  
A E Murphy ◽  
E J Sanders
Keyword(s):  
Gene Expression ◽  
Growth Hormone ◽  
Nervous System ◽  
Pituitary Gland ◽  
Neural Development ◽  
Growth Hormone Receptor ◽  
Neural Retina ◽  
Full Length ◽  
Chick Embryos ◽  
Gh Gene

Growth hormone (GH) is primarily produced in the pituitary gland, although GH gene expression also occurs in the central and autonomic nervous systems. GH-immunoreactive proteins are abundant in the brain, spinal cord, and peripheral nerves. The appearance of GH in these tissues occurs prior to the ontogenic differentiation of the pituitary gland and prior to the presence of GH in systemic circulation. Neural GH is also present in neonates, juveniles, and adults and is independent of changes in pituitary GH secretion. Neural GH is therefore likely to have local roles in neural development or neural function, especially as GH receptors (GHRs) are widespread in the nervous system. In recent studies, GH mRNA and GH immunoreactive proteins have been identified in the neural retina of embryonic chicks. GH immunoreactivity is present in the optic cup of chick embryos at embryonic day (ED) 3 of the 21-d incubation period. It is widespread in the neural retina by ED 7 but also present in the nonpigmented retina, choroid, sclera, and cornea. This immunoreactivity is associated with proteins in the neural retina comparable in size with those in the adult pituitary gland, although it is primarily associated with 15–16 kDa moieties rather than with the full-length molecule of approximately 22 kDa. These small GH moieties may reflect proteolytic fragments of "monomer" GH and (or) the presence of different GH gene transcripts, since full-length and truncated GH cDNAs are present in retinal tissue extracts. The GH immunoreactivity in the retina persists throughout embryonic development but is not present in juvenile birds (after 6 weeks of age). This immunoreactivity is also associated with the presence of GH receptor (GHR) immunoreactivity and GHR mRNA in ocular tissues of chick embryos. The retina is thus an extrapituitary site of GH gene expression during early development and is probably an autocrine or paracrine site of GH action. The marked ontogenic pattern of GH immunoreactivity in the retina suggests hitherto unsuspected roles for GH in neurogenesis or ocular development.Key words: growth hormone, growth hormone receptor, nervous system, retina, autocrine, paracrine.

172 IN VITRO EXPOSURE TO XENOESTROGENS INDUCES GROWTH HORMONE TRANSCRIPTION AND RELEASE VIA AN ESTROGEN RECEPTOR-DEPENDENT PATHWAY IN RAT PITUITARY GH3 CELLS

2008 ◽  
Vol 20 (1) ◽  
pp. 166
Author(s):  
V.-H. Dang ◽  
E.-B. Jeung
Keyword(s):  
Gene Expression ◽  
Growth Hormone ◽  
Estrogen Receptor ◽  
Gene Transcription ◽  
Gh3 Cells ◽  
Pituitary Cells ◽  
Rat Pituitary ◽  
In Vitro Exposure ◽  
Gh Gene

The term endocrine disruptor (ED) has been used widely to characterize natural and synthetic environmental compounds that may interfere with the endocrine system(s) of humans and wildlife. In previous studies, we demonstrated that in vitro single exposure to EDs induces CaBP-9k expression, a useful biomarker for detecting the estrogenic activities of EDs in rat pituitary GH3 cells. Here we employ the identical model to examine the effects of EDs in the regulation of growth hormone (GH) gene expression, an important hormone in growth, development, and body composition. We measured levels of GH mRNA transcription and GH release using semi-quantitative RT-PCR and EIA kit, respectively. GH3 cells were treated with alkyphenols (APs), i.e., octyl-phenol (OP), nonyl-phenol (NP), and bisphenol A (BPA), in a dose-dependent manner (10–5, 10–6, and 10–7 M) and harvested following 24 h of treatment. Cells were also exposed to a high concentration (10–5 M) of OP, NP, or BPA and harvested at various time points (1, 3, 6, 12, and 24 h). An anti-estrogen, ICI 182780 (10–7 M) was used to examine the potential involvement of estrogen receptor (ER) in the induction of GH by EDs through an ER-mediated pathway. The data were analyzed by one-way ANOVA, followed by Tukey's multiple comparison. OP, NP, and BPA induced a significant increase in GH gene expression at high (10–5 M) and medium (10–6 M) doses at 24 h. ED-exposure induced a marked increase in GH gene transcription as early as 6 h and peaked at 12 h. Co-treatment with ICI 182780 significantly attenuated ED-induced GH expression in GH3 cells. Interestingly, the level of in vitro GH release was increased significantly at 24 h in response to OP, NP, or BPA, whereas co-treatment with ICI 182780 significantly diminished ED-induced GH secretion in GH3 cells, indicating that ER may play a part in both GH gene transcription and GH release in these cells. Here we demonstrate for the first time that single in vitro exposure to OP, NP, or BPA results in an increase in GH expression at 24 h in GH3 rat pituitary cells. These results may provide new insight into the mode of ED action in GH gene regulation as well as the biological pathway underlying these molecular events. Furthermore, data showing GH responsiveness evoked by EDs supports the aim to develop an assay for use in predicting adverse health effects of EDs in humans and wildlife.

scholarly journals A microarray gene analysis of peripheral whole blood in normal adult male rats after long-term GH gene therapy

2010 ◽  
Vol 15 (2) ◽  
Author(s):  
Ying Qin ◽  
Ya-Ping Tian
Keyword(s):  
Gene Expression ◽  
Gene Therapy ◽  
Real Time ◽  
Microarray Data ◽  
Whole Blood ◽  
Normal Subjects ◽  
Male Rats ◽  
Blood Samples ◽  
Gh Gene

AbstractThe main aims of this study were to determine the effects of GH gene abuse/misuse in normal animals and to discover genes that could be used as candidate biomarkers for the detection of GH gene therapy abuse/misuse in humans. We determined the global gene expression profile of peripheral whole blood from normal adult male rats after long-term GH gene therapy using CapitalBio 27 K Rat Genome Oligo Arrays. Sixty one genes were found to be differentially expressed in GH gene-treated rats 24 weeks after receiving GH gene therapy, at a two-fold higher or lower level compared to the empty vector group (p < 0.05). These genes were mainly associated with angiogenesis, oncogenesis, apoptosis, immune networks, signaling pathways, general metabolism, type I diabetes mellitus, carbon fixation, cell adhesion molecules, and cytokine-cytokine receptor interaction. The results imply that exogenous GH gene expression in normal subjects is likely to induce cellular changes in the metabolism, signal pathways and immunity. A real-time qRT-PCR analysis of a selection of the genes confirmed the microarray data. Eight differently expressed genes were selected as candidate biomarkers from among these 61 genes. These 8 showed five-fold higher or lower expression levels after the GH gene transduction (p < 0.05). They were then validated in real-time PCR experiments using 15 single-treated blood samples and 10 control blood samples. In summary, we detected the gene expression profiles of rat peripheral whole blood after long-term GH gene therapy and screened eight genes as candidate biomarkers based on the microarray data. This will contribute to an increased mechanistic understanding of the effects of chronic GH gene therapy abuse/misuse in normal subjects.

Signaling mechanisms for α2-adrenergic inhibition of PACAP-induced growth hormone secretion and gene expression grass carp pituitary cells

2007 ◽  
Vol 292 (6) ◽  
pp. E1750-E1762 ◽  
Author(s):  
Xinyan Wang ◽  
Mable M. S. Chu ◽  
Anderson O. L. Wong
Keyword(s):  
Gene Expression ◽  
Growth Hormone ◽  
Adenylate Cyclase ◽  
Grass Carp ◽  
Promoter Activity ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Pituitary Cells ◽  
Gh Secretion ◽  
Gh Gene

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a potent growth hormone (GH)-releasing factor in lower vertebrates. However, its functional interactions with other GH regulators have not been fully characterized. In fish models, norepinephrine (NE) inhibits GH release at the pituitary cell level, but its effects on GH synthesis have yet to be determined. We examined adrenergic inhibition of PACAP-induced GH secretion and GH gene expression using grass carp pituitary cells as a cell model. Through activation of pituitary α2-adrenoreceptors, NE or the α2-agonist clonidine reduced both basal and PACAP-induced GH release and GH mRNA expression. In carp pituitary cells, clonidine also suppressed cAMP production and intracellular Ca2+ levels and blocked PACAP induction of these two second messenger signals. In GH3 cells transfected with a reporter carrying the grass carp GH promoter, PACAP stimulation increased GH promoter activity, and this stimulatory effect could be abolished by NE treatment. In parallel experiments, clonidine reduced GH primary transcript and GH promoter activity without affecting GH mRNA stability, and these inhibitory actions were mimicked by inhibiting adenylate cyclase (AC), blocking protein kinase A (PKA), removing extracellular Ca2+ in the culture medium, or inactivating L-type voltage-sensitive Ca2+ channels (VSCC). Since our recent studies have shown that PACAP can induce GH secretion in carp pituitary cells through cAMP/PKA- and Ca2+/calmodulin-dependent mechanisms, these results, taken together, suggest that α2-adrenergic stimulation in the carp pituitary may inhibit PACAP-induced GH release and GH gene transcription by blocking the AC/cAMP/PKA pathway and Ca2+ entry through L-type VSCC.

scholarly journals Effect of neonatal hyperthyroidism on GH gene expression reprogramming and physiological repercussions in rat adulthood

2006 ◽  
Vol 190 (2) ◽  
pp. 407-414 ◽  
Author(s):  
Kely de Picoli Souza ◽  
Francemilson Goulart da Silva ◽  
Maria Tereza Nunes
Keyword(s):  
Gene Expression ◽  
Body Weight ◽  
Adult Life ◽  
Control Group ◽  
Postnatal Life ◽  
Mrna Levels ◽  
Mineral Density ◽  
Thyroid State ◽  
Gh Gene ◽  
Neonatal Hyperthyroidism

The neonatal period (NP) is a critical phase of the development in which the expression pattern of most genes is established. Thyroid hormones (TH) play a key role in this process and, alterations in its availability in the NP may lead to different patterns of gene expression, which might reflect in the permanent expression of several genes in the adulthood. GH gene expression in the pituitary is greatly dependent on TH in the early postnatal life; thus, modifications of thyroid state in NP might lead to alterations in GH gene expression as well as to physiological repercussions in the adult life. This study aimed to investigate this possibility by means of the induction of a neonatal hyperthyroidism in rats (4 μg of 3,5,3′-triiodo-l-thyronine (T3)/100 g body weight, s.c.) for 5, 15 or 30 days, and further evaluation of GH gene expression, as well as its physiological consequences in adult rats subjected to a transient hyperthyroidism in the first 30 days of life. GH mRNA level was shown to be increased in T3-treated rats for 5 days; when the treatment was extended to 15 or 30 days, the GH mRNA levels were similar to the control group. Moreover, rats treated with T3 for 30 days and killed when 90 days old, i.e., 60 days at the end of the T3 treatment, showed decreased GH mRNA content, body weight, bone mineral density, and lean body mass. In conclusion: (1) T3 effects on GH gene expression depend on the period of life in which the hyperthyroidism is set and on the length of T3 treatment in the NP and (2) transient neonatal hyperthyroidism leads to a lower GH mRNA expression in adult life accompanied by physiological repercussions indicative of GH deficiency.

PKC and ERK are differentially involved in gonadotropin-releasing hormone-induced growth hormone gene expression in the goldfish pituitary

2005 ◽  
Vol 289 (6) ◽  
pp. R1625-R1633 ◽  
Author(s):  
Christian Klausen ◽  
Takeshi Tsuchiya ◽  
John P. Chang ◽  
Hamid R. Habibi
Keyword(s):  
Gene Expression ◽  
Growth Hormone ◽  
Primary Cultures ◽  
Gonadotropin Releasing Hormone ◽  
Growth Hormone Gene ◽  
Pituitary Cells ◽  
Mrna Levels ◽  
Releasing Hormone ◽  
Gh Secretion ◽  
Gh Gene

Gonadotropin-releasing hormone (GnRH) is produced by the hypothalamus and stimulates the synthesis and secretion of gonadotropin hormones. In addition, GnRH also stimulates the production and secretion of growth hormone (GH) in some fish species and in humans with certain clinical disorders. In the goldfish pituitary, GH secretion and gene expression are regulated by two endogenous forms of GnRH known as salmon GnRH and chicken GnRH-II. It is well established that PKC mediates GnRH-stimulated GH secretion in the goldfish pituitary. In contrast, the signal transduction of GnRH-induced GH gene expression has not been elucidated in any model system. In this study, we demonstrate, for the first time, the presence of novel and atypical PKC isoforms in the pituitary of a fish. Moreover, our results indicate that conventional PKCα is present selectively in GH-producing cells. Treatment of primary cultures of dispersed goldfish pituitary cells with PKC activators (phorbol ester or diacylglycerol analog) did not affect basal or GnRH-induced GH mRNA levels, and two different inhibitors of PKC (calphostin C and GF109203X) did not reduce the effects of GnRH on GH gene expression. Together, these results suggest that, in contrast to secretion, conventional and novel PKCs are not involved in GnRH-stimulated increases in GH mRNA levels in the goldfish pituitary. Instead, PD98059 inhibited GnRH-induced GH gene expression, suggesting that the ERK signaling pathway is involved. The results presented here provide novel insights into the functional specificity of GnRH-induced signaling and the regulation of GH gene expression.

scholarly journals Modulation of Calmodulin Gene Expression as a Novel Mechanism for Growth Hormone Feedback Control by Insulin-like Growth Factor in Grass Carp Pituitary Cells

Endocrinology ◽  
2005 ◽  
Vol 146 (9) ◽  
pp. 3821-3835 ◽  
Author(s):  
Longfei Huo ◽  
Guodong Fu ◽  
Xinyan Wang ◽  
Wendy K. W. Ko ◽  
Anderson O. L. Wong
Keyword(s):  
Gene Expression ◽  
Feedback Control ◽  
Grass Carp ◽  
Cell Model ◽  
Pituitary Hormone ◽  
Pituitary Cells ◽  
Mrna Levels ◽  
Hormone Synthesis ◽  
Igf I ◽  
Gh Gene

Abstract Calmodulin (CaM), the Ca2+ sensor in living cells, is essential for biological functions mediated by Ca2+-dependent mechanisms. However, modulation of CaM gene expression at the pituitary level as a means to regulate pituitary hormone synthesis has not been characterized. In this study we examined the functional role of CaM in the feedback control of GH by IGF using grass carp pituitary cells as a cell model. To establish the structural identity of CaM expressed in the grass carp, a CaM cDNA, CaM-L, was isolated from the carp pituitary using 3′/5′ rapid amplification of cDNA ends. The open reading frame of this cDNA encodes a 149-amino acid protein sharing the same primary structure with CaMs reported in mammals, birds, and amphibians. This CaM cDNA is phylogenetically related to the CaM I gene family, and its transcripts are ubiquitously expressed in the grass carp. In carp pituitary cells, IGF-I and IGF-II induced CaM mRNA expression with a concurrent drop in GH transcript levels. These stimulatory effects on CaM mRNA levels were not mimicked by insulin and appeared to be a direct consequence of IGF activation of CaM gene transcription without altering CaM transcript stability. CaM antagonism and inactivation of calcineurin blocked the inhibitory effects of IGF-I and IGF-II on GH gene expression, and CaM overexpression also suppressed the 5′ promoter activity of the grass carp GH gene. These results, as a whole, provide evidence for the first time that IGF feedback on GH gene expression is mediated by activation of CaM gene expression at the pituitary level.

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