scholarly journals 17α-Estradiol Modulates IGF1 and Hepatic Gene Expression in a Sex-Specific Manner

2020 ◽  
Author(s):  
Silvana Sidhom ◽  
Augusto Schneider ◽  
Yimin Fang ◽  
Samuel McFadden ◽  
Justin Darcy ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Insulin Sensitivity ◽  
Growth Hormone Receptor ◽  
Health Benefits ◽  
Male Mice ◽  
Wild Type ◽  
Somatotropic Axis ◽  
Gh Secretion ◽  
17Β Estradiol ◽  
Estradiol 17Β

Abstract Aging is the greatest risk factor for most chronic diseases. The somatotropic axis is one of the most conserved biological pathways that regulates aging across species. 17α-Estradiol (17α-E2), a diastereomer of 17β-estradiol (17β-E2), was recently found to elicit health benefits, including improved insulin sensitivity and extend longevity exclusively in male mice. Given that 17β-E2 is known to modulate somatotropic signaling in females through actions in the pituitary and liver, we hypothesized that 17α-E2 may be modulating the somatotropic axis in males, thereby contributing to health benefits. Herein, we demonstrate that 17α-E2 increases hepatic insulin-like growth factor 1 (IGF1) production in male mice without inducing any changes in pulsatile growth hormone (GH) secretion. Using growth hormone receptor knockout (GHRKO) mice, we subsequently determined that the induction of hepatic IGF1 by 17α-E2 is dependent upon GH signaling in male mice, and that 17α-E2 elicits no effects on IGF1 production in female mice. We also determined that 17α-E2 failed to feminize the hepatic transcriptional profile in normal (N) male mice, as evidenced by a clear divergence between the sexes, regardless of treatment. Conversely, significant overlap in transcriptional profiles was observed between sexes in GHRKO mice, and this was unaffected by 17α-E2 treatment. Based on these findings, we propose that 17α-E2 acts as a pleiotropic pathway modulator in male mice by uncoupling IGF1 production from insulin sensitivity. In summary, 17α-E2 treatment upregulates IGF1 production in wild-type (and N) male mice in what appears to be a GH-dependent fashion, while no effects in female IGF1 production are observed following 17α-E2 treatment.

scholarly journals Removal of growth hormone receptor (GHR) in muscle of male mice replicates some of the health benefits seen in global GHR−/− mice

Aging ◽  
2015 ◽  
Vol 7 (7) ◽  
pp. 500-512 ◽  
Author(s):  
Edward O. List ◽  
Darlene E. Berryman ◽  
Yuji Ikeno ◽  
Gene B. Hubbard ◽  
Kevin Funk ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Hormone Receptor ◽  
Growth Hormone Receptor ◽  
Health Benefits ◽  
Male Mice

scholarly journals Egg size-dependent expression of growth hormone receptor accompanies compensatory growth in fish

2011 ◽  
Vol 279 (1728) ◽  
pp. 592-600 ◽  
Author(s):  
F. H. I. D. Segers ◽  
G. Berishvili ◽  
B. Taborsky
Keyword(s):  
Growth Hormone ◽  
Hormone Receptor ◽  
Egg Size ◽  
Growth Hormone Receptor ◽  
Yolk Sac ◽  
Juvenile Growth ◽  
Somatotropic Axis ◽  
Expression Levels ◽  
Potential Link ◽  
Adaptive Adjustment

Large egg size usually boosts offspring survival, but mothers have to trade off egg size against egg number. Therefore, females often produce smaller eggs when environmental conditions for offspring are favourable, which is subsequently compensated for by accelerated juvenile growth. How this rapid growth is modulated on a molecular level is still unclear. As the somatotropic axis is a key regulator of early growth in vertebrates, we investigated the effect of egg size on three key genes belonging to this axis, at different ontogenetic stages in a mouthbrooding cichlid ( Simochromis pleurospilus ). The expression levels of one of them, the growth hormone receptor ( GHR ), were significantly higher in large than in small eggs, but remarkably, this pattern was reversed after hatching: young originating from small eggs had significantly higher GHR expression levels as yolk sac larvae and as juveniles. GHR expression in yolk sac larvae was positively correlated with juvenile growth rate and correspondingly fish originating from small eggs grew faster. This enabled them to catch up fully in size within eight weeks with conspecifics from larger eggs. This is the first evidence for a potential link between egg size, an important maternal effect, and offspring gene expression, which mediates an adaptive adjustment in a relevant hormonal axis.

scholarly journals Distinct growth hormone receptor signaling modes regulate skeletal muscle development and insulin sensitivity in mice

2010 ◽  
Vol 120 (11) ◽  
pp. 4007-4020 ◽  
Author(s):  
Mahendra D. Mavalli ◽  
Douglas J. DiGirolamo ◽  
Yong Fan ◽  
Ryan C. Riddle ◽  
Kenneth S. Campbell ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Growth Hormone ◽  
Insulin Sensitivity ◽  
Hormone Receptor ◽  
Growth Hormone Receptor ◽  
Muscle Development ◽  
Receptor Signaling ◽  
Skeletal Muscle Development

Loss of growth hormone signaling in the mouse germline or in adulthood reduces islet mass and alters islet function with notable sex differences

2021 ◽  
Author(s):  
Silvana Duran-Ortiz ◽  
Kathryn L. Corbin ◽  
Ishrat Jahan ◽  
Nicholas B. Whitticar ◽  
Sarah E Morris ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Insulin Secretion ◽  
Insulin Sensitivity ◽  
Glucose Tolerance ◽  
Body Fat ◽  
Isolated Islets ◽  
Wild Type ◽  
Cross Sectional ◽  
Islet Mass ◽  
The Impact

In the endocrine pancreas, growth hormone (GH) is known to promote pancreatic islet growth and insulin secretion. In this study, we show that GH receptor (GHR) loss in the germline and in adulthood impacts islet mass in general but more profoundly in male mice. GHR knockout (GHRKO) mice have enhanced insulin sensitivity and low circulating insulin. We show that the total cross-sectional area of isolated islets (estimated islet mass) was reduced by 72% in male but by only 29% in female GHRKO mice compared to wild type controls. Also, islets from GHRKO mice secreted ~50% less glucose-stimulated insulin compared to size-matched islets from wild type mice. We next used mice with a floxed Ghr gene to knock down the GHR in adult mice at six-months of age (6mGHRKO) and examined the impact on glucose and islet metabolism. By 12-months of age, female 6mGHRKO mice had increased body fat and reduced islet mass but had no change in glucose tolerance or insulin sensitivity. However, male 6mGHRKO mice had nearly twice as much body fat, substantially reduced islet mass, and enhanced insulin sensitivity, but no change in glucose tolerance. Despite large losses in islet mass, glucose-stimulated insulin secretion from isolated islets was not significantly different between male 6mGHRKO and controls while isolated islets from female 6mGHRKO mice showed increased glucose-stimulated insulin release. Our findings demonstrate the importance of GH to islet mass throughout life and that unique sex-specific adaptations to the loss of GH signaling allow mice to maintain normal glucose metabolism.

361 GROWTH HORMONE RECEPTOR MUTANT PIGS PRODUCED BY USING THE CLUSTERED REGULARLY INTERSPACED SHORT PALINDROMIC REPEATS (CRISPR) AND CRISPR-ASSOCIATED SYSTEMS IN IN VITRO-PRODUCED ZYGOTES

2015 ◽  
Vol 27 (1) ◽  
pp. 269 ◽  
Author(s):  
M. Kurome ◽  
M. Dahlhoff ◽  
S. Bultmann ◽  
S. Krebs ◽  
H. Blum ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Hormone Receptor ◽  
Growth Hormone Receptor ◽  
Large Animal Model ◽  
Large Animal ◽  
Single Mutation ◽  
Wild Type ◽  
Ghr Gene ◽  
Normal Fertilization

Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) technology is considered as an efficient strategy for generating gene edited large animals, such as pigs. Compared to somatic cell nuclear transfer, this new technology offers a relatively simple way to generate mutant pigs by direct injection of RNA into the cytoplasm of zygotes. Moreover, the use of in vitro produced zygotes would provide a highly effective and practical method for the production of porcine disease models for biomedical research. Here we examined the production efficiency of growth hormone receptor (GHR) mutant pigs by the combination of the CRISPR/Cas system and in vitro produced zygotes. In vitro maturation (IVM) of oocytes was performed as described previously (Kurome et al., Meth. Mol. Biol., in press). In all experiments, the same batch of frozen sperm was used. After IVM, around 20 oocytes with expanded cumulus cells were incubated with 5 × 104 spermatozoa in a 100-μL drop of porcine fertilization medium for 7 h. In vitro-produced embryos were assessed by the ratio of normal fertilization (eggs with 2 pronuclei) and blastocyst formation at Day 7. The Cas9 mRNA and a single guide RNA, recognising a short sequence of 20 base pairs in exon 3 of the GHR gene, were injected directly into the cytoplasm of the embryos 8.5 to 9.5 h after IVF. Injected embryos were transferred laparoscopically to recipient pigs, and 86.4% (57/66) of sperm-penetrated oocytes (66/96) exhibited normal fertilization. Incidence of polyspermy was relatively low (9/66, 13.6%). Developmental ability of in vitro-produced embryos to the blastocyst stage was 17.4% (24/138). In total, 426 RNA-injected embryos were transferred into 2 recipients, one of which became pregnant and gave birth to 8 piglets. All piglets were clinically healthy and developed normally. In 3 out of 8 piglets (37.5%), mutations were introduced. Next-generation sequencing revealed that all of them were mosaics: one with a single mutation (22% wild-type/78% mutant) and 2 piglets with 2 different mutations (80% wild-type/2% mutant_1/18% mutant_2 and 94% wild-type/4% mutant_1/2% mutant_2). Four out of 5 mutations caused a frameshift in the GHR gene. Our study reports for the first time generation of GHR mutant pigs by the use of the CRISPR/Cas system in in vitro-produced zygotes. Because all GHR mutant offspring were mosaic, Cas9 activation probably occurred after the 1-cell stage under our experimental conditions. The founder animal with the highest proportion of mutant GHR alleles will be used for breeding to establish a large animal model for Laron syndrome.This work is supported by the German Research Council (TR-CRC 127).

scholarly journals A Postweaning Reduction in Circulating Ghrelin Temporarily Alters Growth Hormone (GH) Responsiveness to GH-Releasing Hormone in Male Mice But Does Not Affect Somatic Growth

Endocrinology ◽  
2010 ◽  
Vol 151 (4) ◽  
pp. 1743-1750 ◽  
Author(s):  
Hiroyuki Ariyasu ◽  
Hiroshi Iwakura ◽  
Go Yamada ◽  
Naotetsu Kanamoto ◽  
Mika Bando ◽  
...  
Keyword(s):  
Diphtheria Toxin ◽  
Somatic Growth ◽  
Male Mice ◽  
Wild Type ◽  
Endogenous Ligand ◽  
Gh Secretion ◽  
Igf I ◽  
Ghrelin Secretion ◽  
Physiologic Role

Ghrelin was initially identified as an endogenous ligand for the GH secretagogue receptor. When administrated exogenously, ghrelin stimulates GH release and food intake. Previous reports in ghrelin-null mice, which do not exhibit impaired growth nor appetite, question the physiologic role of ghrelin in the regulation of the GH/IGF-I axis. In this study, we generated a transgenic mouse that expresses human diphtheria toxin (DT) receptor (DTR) cDNA in ghrelin-secretion cells [ghrelin-promoter DTR-transgenic (GPDTR-Tg) mice]. Administration of DT to this mouse ablates ghrelin-secretion cells in a controlled manner. After injection of DT into GPDTR-Tg mice, ghrelin-secreting cells were ablated, and plasma levels of ghrelin were markedly decreased [nontransgenic littermates, 70.6 ± 10.2 fmol/ml vs. GPDTR-Tg, 5.3 ± 2.3 fmol/ml]. To elucidate the physiological roles of circulating ghrelin on GH secretion and somatic growth, 3-wk-old GPDTR-Tg mice were treated with DT twice a week for 5 wk. The GH responses to GHRH in male GPDTR-Tg mice were significantly lower than those in wild-type mice at 5 wk of age. However, those were normalized at 8 wk of age. In contrast, in female mice, there was no difference in GH response to GHRH between GPDTR-Tg mice and controls at 5 or 8 wk of age. The gender-dependent differences in response to GHRH were observed in ghrelin-ablated mice. However, GPDTR-Tg mice did not display any decreases in IGF-I levels or any growth retardation. Our results strongly suggest that circulating ghrelin does not play a crucial role in somatic growth.

Substitution of Trp1242 of TM17 alters substrate specificity of human multidrug resistance protein 3

2003 ◽  
Vol 284 (2) ◽  
pp. G280-G289 ◽  
Author(s):  
Curtis J. Oleschuk ◽  
Roger G. Deeley ◽  
Susan P. C. Cole
Keyword(s):  
Multidrug Resistance ◽  
Substrate Specificity ◽  
Multidrug Resistance Protein ◽  
Wild Type ◽  
Multidrug Resistance Protein 3 ◽  
17Β Estradiol ◽  
Resistance Protein ◽  
Estradiol 17Β ◽  
Taurocholate Transport

Multidrug resistance protein 3 (MRP3) is an ATP-dependent transporter of 17β-estradiol 17β(d-glucuronide) (E217βG), leukotriene C4 (LTC4), methotrexate, and the bile salts taurocholate and glycocholate. In the present study, the role of a highly conserved Trp residue at position 1242 on MRP3 transport function was examined by expressing wild-type MRP3 and Ala-, Cys-, Phe-, Tyr-, and Pro-substituted mutants in human embryonic kidney 293T cells. Four MRP3-Trp1242 mutants showed significantly increased E217βG uptake, whereas transport by the Pro mutant was undetectable. Similarly, the Pro mutant did not transport LTC4. By comparison, LTC4transport by the Ala, Cys, Phe, and Tyr mutants was reduced by ∼35%. The Ala, Cys, Phe, and Tyr mutants all showed greatly reduced methotrexate and leucovorin transport, except the Tyr mutant, which transported leucovorin at levels comparable with wild-type MRP3. In contrast, the MRP3-Trp1242 substitutions did not significantly affect taurocholate transport or taurocholate and glycocholate inhibition of E217βG uptake. Thus Trp1242 substitutions markedly alter the substrate specificity of MRP3 but leave bile salt binding and transport intact.

Growth hormone regulation of follicular growth

2012 ◽  
Vol 24 (1) ◽  
pp. 19 ◽  
Author(s):  
Matthew C. Lucy
Keyword(s):  
Growth Hormone ◽  
Insulin Sensitivity ◽  
Growth Factor ◽  
Post Partum ◽  
Feedback Signal ◽  
Hormone Regulation ◽  
Primary Target ◽  
Igf Binding Proteins ◽  
Somatotropic Axis ◽  
Local Synthesis

The somatotropic axis – consisting of growth hormone (GH), the insulin-like growth factors 1 and 2 (IGF1 and IGF2), GH binding protein (GHBP), IGF binding proteins (IGFBPs) 1 to 6, and the cell-surface receptors for GH and the IGFs – has major effects on growth, lactation and reproduction. The primary target tissues for GH are involved in growth and metabolism. The functionality of the somatotropic axis depends in part on the expression of liver GH receptor (GHR), which determines the amount of IGF1 released from the liver in response to GH. The IGF1 acts as a pleiotropic growth factor and also serves as the endocrine negative feedback signal controlling pituitary GH secretion. Growth hormone and IGF1 undergo dynamic changes throughout the life cycle, particularly when animals are either growing, early post partum or lactating. Cells within the reproductive tract can respond directly to GH but to a lesser degree than the primary target tissues. The major impact that GH has on reproduction, therefore, may be secondary to its systemic effects on metabolism (including insulin sensitivity) or secondary to the capacity for GH to control IGF1 secretion. Insulin-like growth factor 1 and IGFBP are also synthesised within the ovary and this local synthesis is a component of the collective IGF1 action on the follicle. Future studies of GH should focus on its direct effects on the follicle as well as its indirect effects mediated by shifts in nutrient metabolism, insulin sensitivity, IGF1 and IGFBP.

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