Alterations in growth hormone receptor abundance regulate growth hormone signaling in murine obstructive cholestasis

2005 ◽  
Vol 288 (5) ◽  
pp. G986-G993 ◽  
Author(s):  
Matthew A. Held ◽  
Wilfredo Cosme-Blanco ◽  
Lisa M. Difedele ◽  
Erin L. Bonkowski ◽  
Ram K. Menon ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Growth Hormone ◽  
Growth Hormone Receptor ◽  
Fat Free Mass ◽  
Cholestatic Liver Disease ◽  
Duct Ligation ◽  
Obstructive Cholestasis ◽  
Igf I ◽  
Ad Libitum ◽  
Gh Resistance

Children with cholestatic liver diseases, in particular biliary atresia, may develop an acquired growth hormone (GH) resistance. This is characterized by normal GH secretion, reduced liver GH receptor (GHR) abundance, and reduced circulating insulin-like growth factor I (IGF-I). Consequences include linear growth failure, reduced muscle mass, and increased perioperative morbidity and mortality. However, the molecular basis for altered GH signaling in liver and skeletal muscle in cholestatic liver disease is not known. We hypothesized that reduced IGF-I expression in obstructive cholestasis would be associated with downregulation of the GHR and impaired phosphorylation of signal transducers and activators of transcription (STAT5). Body composition was determined in C57BL/6J male mice after bile duct ligation (BDL) relative to pair-fed (PF) and ad libitum-fed controls. GHR, STAT5, Sp3, and IGF-I expression and/or DNA binding were assessed using immunoblots, electrophoretic mobility shift assays, and/or real time RT-PCR. Fat-free mass was reduced in PF mice relative to ad libitum-fed controls. BDL led to a further reduction in fat mass and fat-free mass relative to PF controls. TNF-α was increased in liver and skeletal muscle of BDL mice. This was associated with reduced GH-dependent STAT5 activation and IGF-I RNA expression. GHR expression was reduced in BDL mice; in liver, this was associated with reduced Sp3 binding to a GHR gene promoter cis element. Wasting in murine obstructive cholestasis is due to combined effects of reduced caloric intake and biliary obstruction. GH resistance due to downregulation of GHR expression may be attributed primarily to the obstructive cholestasis; therapies that specifically increase GHR expression may restore GH signaling in this setting.

scholarly journals Dairy cows experience selective reduction of the hepatic growth hormone receptor during the periparturient period

2004 ◽  
Vol 181 (2) ◽  
pp. 281-290 ◽  
Author(s):  
J Wook Kim ◽  
RP Rhoads ◽  
SS Block ◽  
TR Overton ◽  
SJ Frank ◽  
...  
Keyword(s):  
Gene Expression ◽  
Skeletal Muscle ◽  
Growth Hormone ◽  
Dairy Cows ◽  
Hormone Receptor ◽  
Growth Hormone Receptor ◽  
Late Pregnancy ◽  
Target Tissue ◽  
Ghr Gene ◽  
Igf I

At parturition, dairy cows experience a 70% reduction in plasma IGF-I. This reduction coincides with decreased abundance of GHR1A, the liver-specific transcript of the growth hormone receptor (GHR) gene, suggesting impaired growth hormone-dependent synthesis of IGF-I. It is not immediately obvious that the periparturient reduction in GHR1A is sufficient to reduce hepatic GHR abundance. This is because approximately 50% of total GHR mRNA abundance in prepartum liver is accounted for by ubiquitously expressed transcripts which remain collectively unchanged at parturition. In addition, the possibility that parturition alters GHR expression in other growth hormone target tissue has not been examined. To address these questions, we measured GHR gene expression and GHR protein in liver and skeletal muscle of four dairy cows on days -35,+3 and+56 (relative to parturition on day 0). Hepatic GHR abundance and GHR1A transcripts were lower on day+3 than on day -35 and returned to late pregnancy value by day+56. Additional studies in two other groups of cows indicated that the hepatic levels of the GHR protein recovered substantially within 10 days after parturition. These changes occurred without variation in the abundance of HNF4, a liver-enriched transcription factor activating the promoter responsible for GHR1A synthesis. In contrast to liver, levels of GHR gene expression and GHR protein were identical on days -35,+3 and+56 in skeletal muscle. These data suggest a role for the GHR in regulating tissue-specific changes in growth hormone responsiveness in periparturient dairy cows.

scholarly journals Effect of Growth Hormone and Calorie Restriction on the Expression of Antioxidant Enzymes in the Liver and Kidney of Growth Hormone Receptor Knockout Mice

2017 ◽  
Vol 2 (2) ◽  
pp. 136-141
Author(s):  
Khalid A Al-Regaiey
Keyword(s):  
Growth Hormone ◽  
Antioxidant Enzymes ◽  
Defense Mechanisms ◽  
Growth Hormone Receptor ◽  
Oxidative Stress Marker ◽  
Gh Receptor ◽  
Liver And Kidney ◽  
Ad Libitum ◽  
Gpx Activity ◽  
Gh Resistance

Caloric restriction (CR) can delay aging and prolong life span and these actions may be related to reduced oxidative damage. Mice with disrupted growth hormone (GH) receptor/binding protein knockout (GHRKO) live significantly longer than their normal siblings. Therefore, it is of interest to examine the effects of chronic CR on hepatic and renal antioxidant enzymes as well as lipid peroxidation (LP) as an oxidative stress marker in GHRKO mice. Female GHRKO and normal mice were either fed ad libitum (AL) or subjected to 30% CR starting at 2 months of age and examined at the age of 9 months. In the liver, catalase (CAT) activity was significantly increased in GHRKO-AL as compared to normal control -AL animals. CR reduced CAT activity in both GHRKO and normal phenotypes. Cu/Zn superoxide dismutase (SOD1) activity was also higher in GHRKO-AL as compared to normal-AL mice. However, CR reduced SOD1 activity in GHRKO mutants. Glutathione peroxidase (GPx) activity was significantly decreased in GHRKO-AL mice and further reduced in GHRKO-CR group of animals. CR significantly increased LP in GHRKOs while its activity was not altered in GHRKO-AL group of mice. In the kidney, CAT activity was lower in GHRKO-AL as compared to normal-AL, however CR did not induce any significant effect in both phenotypes. Similarly, SOD1 levels were significantly lower in GHRKO than in normal mice. GPx expression was higher in GHRKO-AL as compared to control-AL. CR reduced GPx activity in GHRKO mice but increased it in controls as compared to their AL counterparts. There was no difference in LP expression between GHRKO-AL and normal-AL mice. However, CR significantly increased its levels in both phenotypes. Although these findings do not support the hypothesis that CR would increase the capacity of ROS defense mechanisms in GHRKO mice by increasing antioxidant enzymes levels, they do agree with some of the reported effects of CR on their expression. We suspect that GH resistance and CR may affect aging by different mechanisms and if CR delays aging in GHRKO animals it is not due to changes in the activity of antioxidant enzymes.

scholarly journals Consequences of maternal undernutrition for fetal and postnatal hepatic insulin-like growth factor-I, growth hormone receptor and growth hormone binding protein gene regulation in the rat

1998 ◽  
Vol 20 (3) ◽  
pp. 313-326 ◽  
Author(s):  
SM Woodall ◽  
NS Bassett ◽  
PD Gluckman ◽  
BH Breier
Keyword(s):  
Growth Hormone ◽  
Growth Hormone Receptor ◽  
Growth Failure ◽  
Postnatal Growth ◽  
Exon 2 ◽  
Maternal Undernutrition ◽  
Igf I ◽  
Exon 1 ◽  
Ad Libitum ◽  
Postnatal Growth Failure

The mechanisms that contribute to postnatal growth failure following intrauterine growth retardation (IUGR) are poorly understood. We demonstrated previously that nutritional deprivation in the pregnant rat leads to IUGR in offspring, postnatal growth failure and to changes in endocrine parameters of the somatotrophic axis. The present study examines the effects of maternal undernutrition (30% of the ad libitum available diet; IUGR group) throughout pregnancy on hepatic insulin-like growth factor-I (IGF-I), growth hormone receptor (GHR) and GH-binding protein (GHBP) gene expression using solution hybridisation/RNase protection assays (RPAs). Animals were killed at fetal (E22, term=23 days) and postnatal (birth, days 5, 9, 15, 21) ages, livers were collected and RNA extracted for RPAs. Results demonstrate the presence of all IGF-I mRNAs resulting from transcription start sites (ss) in exon 1 (ss1/2, ss3, ss2 spliced), exon 2, the two IGF-I E-domain variants (Ea and Eb) as well as GHR and GHBP mRNAs in hepatic tissue at E22 in both the ad libitum fed and IUGR offspring. In the postnatal liver, IGF-I ss1/2, ss3, ss2 spliced, Ea and Eb IGF-I variants as well as GHR and GHBP mRNA transcripts increased in abundance from birth to day 21. IGF-I exon 2 transcripts were relatively constant from E22 until postnatal day 15, then increased at postnatal day 21 in both the ad libitum fed and IUGR offspring. The expressions of all hepatic IGF-I leader exon ss and Ea domain variants were significantly reduced in IUGR offspring (P<0.05) from E22 to postnatal day 9. In contrast, relative abundance of hepatic IGF-I Eb variants, GHR and GHBP mRNAs were unaltered in IUGR offspring compared with the ad libitum fed animals. Whether these postnatal effects of undernutrition are a direct consequence of IUGR or whether they are related, in part, to differences in postnatal food intake remains to be investigated. In summary, we have demonstrated that hepatic IGF-I ss within exon 1 and exon 2 are coordinately regulated. Use of exon 1 ss increased during normal development and decreased with IUGR without changes in GHR or GHBP gene expression. Eb transcripts, thought to represent GH-dependent endocrine regulation of IGF-I, were unchanged in IUGR. These results suggest a possible postreceptor defect in GH action as a consequence of IUGR.

Laron syndrome – A case Report

JMS SKIMS ◽  
2017 ◽  
Vol 20 (2) ◽  
pp. 104-106
Author(s):  
Javaid Ahmad Bhat ◽  
Moomin Hussain Bhat ◽  
Hilal Bhat ◽  
Mona Sood ◽  
Shariq Rashid Masoodi
Keyword(s):  
Growth Hormone ◽  
Case Report ◽  
Hormone Receptor ◽  
Growth Hormone Receptor ◽  
Genetic Disorder ◽  
Female Child ◽  
Receptor Signaling ◽  
Laron Syndrome ◽  
Rare Genetic Disorder ◽  
Igf I

Background : Laron & colleagues (1966) reported a rare genetic disorder in Israliei Jewish sublings which was characterized by insensitivity to growth hormone due to abnormality in growth hormone receptor or post receptor signaling pathway.Case Report: We hereby report a case of a 5 year old female child who presented to us with features similar to Laron syndrome. The diagnosis was made & confirmed by various Lab. investigations like low IGF-I levels and managed accordingly. JMS 2017; 20 (2):104-106  

The interrelationship between and the regulation of hepatic growth hormone receptors and circulating GH binding protein in the pig

1992 ◽  
Vol 126 (2) ◽  
pp. 155-161 ◽  
Author(s):  
Geoffrey R Ambler ◽  
Bernhard H Breier ◽  
Andrzej Surus ◽  
Hugh T Blair ◽  
Stuart N McCutcheon ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Growth Hormone Receptor ◽  
Hormone Receptors ◽  
Binding Capacity ◽  
Binding Protein ◽  
Somatic Growth ◽  
Gh Receptor ◽  
Age Related ◽  
Igf I ◽  
Serum Gh

We evaluated the interrelationship between, and regulation of, the hepatic growth hormone receptor and serum GH binding protein (GH BP) in pigs treated with recombinant porcine growth hormone (rpGH). Infant and pubertal male pigs (N = 5 per group) received either rpGH 0.15 mg/kg daily or diluent intramuscularly for 12 days. Somatic growth, serum IGF-I and GH BP and [125I]bovine GH (bGH) binding to MgCl2-treated hepatic membrane homogenates were examined. Marked age-related increases were seen in serum GH BP (p<0.001) and [125I]bGH binding to hepatic membranes (p<0.001). GH BP was increased in rpGH treated animals (p = 0.03), from 13.8±1.2 (mean±1 x sem) (controls) to 17.8±2.0% in infants, and from 35.2±2.6 (controls) to 41.8±3.4% in pubertal animals. [125I]bGH binding to hepatic membranes was also increased by rpGH treatment (p<0.05), from 7.0±1.6 (controls) to 15.4±3.6% in infants and from 53.7±7.1 (controls) to 65.1±11.8% in pubertal animals. No significant interaction between age and treatment was seen. Overall, serum GH BP correlated significantly with [125I]bGH membrane capacity (r=0.82, p<0.001), with a correlation of r= 0.83 in the infant animals but no significant correlation in the pubertal animals considered alone (r=0.13). Serum IGF-I correlated significantly with serum GH BP (r=0.93, p<0.001) and [125]bGH membrane binding capacity (r = 0.91, p< 0.001). These observations suggest that serum GH BP levels reflect major changes of hepatic GH receptor status. In addition, the present study demonstrates that the hepatic GH receptor can be induced by GH in the infant pig, despite a developmentally low GH receptor population at this age, suggesting potential efficacy of GH at earlier ages than generally considered.

Growth hormone acutely stimulates forearm muscle protein synthesis in normal humans

1991 ◽  
Vol 260 (3) ◽  
pp. E499-E504 ◽  
Author(s):  
D. A. Fryburg ◽  
R. A. Gelfand ◽  
E. J. Barrett
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Growth Hormone ◽  
Protein Synthesis ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Skeletal Muscle Protein ◽  
Skeletal Muscle Protein Synthesis ◽  
Igf I ◽  
Normal Humans

The short-term effects of growth hormone (GH) on skeletal muscle protein synthesis and degradation in normal humans are unknown. We studied seven postabsorptive healthy men (age 18-23 yr) who received GH (0.014 micrograms.kg-1.min-1) via intrabrachial artery infusion for 6 h. The effects of GH on forearm amino acid and glucose balances and on forearm amino acid kinetics [( 3H]Phe and [14C]Leu) were determined after 3 and 6 h of the GH infusion. Forearm deep vein GH rose to 35 +/- 6 ng/ml in response to GH, whereas systemic levels of GH, insulin, and insulin-like growth factor I (IGF-I) were unchanged. Forearm glucose uptake did not change during the study. After 6 h, GH suppressed forearm net release (3 vs. 6 h) of Phe (P less than 0.05), Leu (P less than 0.01), total branched-chain amino acids (P less than 0.025), and essential neutral amino acids (0.05 less than P less than 0.1). The effect on the net balance of Phe and Leu was due to an increase in the tissue uptake for Phe (71%, P less than 0.05) and Leu (37%, P less than 0.005) in the absence of any significant change in release of Phe or Leu from tissue. In the absence of any change in systemic GH, IGF-I, or insulin, these findings suggest that locally infused GH stimulates skeletal muscle protein synthesis. These findings have important physiological implications for both the role of daily GH pulses and the mechanisms through which GH can promote protein anabolism.

Serum lipoprotein changes following IGF-I normalization using a growth hormone receptor antagonist in acromegaly

2002 ◽  
Vol 56 (3) ◽  
pp. 303-311 ◽  
Author(s):  
C. Parkinson ◽  
W. M. Drake ◽  
G. Wieringa ◽  
A. P. Yates ◽  
G. M. Besser ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Receptor Antagonist ◽  
Hormone Receptor ◽  
Growth Hormone Receptor ◽  
Serum Lipoprotein ◽  
Igf I ◽  
Growth Hormone Receptor Antagonist

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

scholarly journals Insulin action in growth hormone-deficient and age-matched control rats: effect of growth hormone treatment

1999 ◽  
Vol 160 (1) ◽  
pp. 127-135 ◽  
Author(s):  
◽  
JL Laustsen ◽  
BS Hansen ◽  
EA Richter
Keyword(s):  
Skeletal Muscle ◽  
Growth Hormone ◽  
Glucose Metabolism ◽  
Recombinant Human Growth Hormone ◽  
Normal Weight ◽  
Lower Amount ◽  
Control Group ◽  
Muscle Fibre Size ◽  
Igf I

The isolated effect of growth hormone on carbohydrate metabolism in rat skeletal muscle was studied in growth hormone-deficient dwarf rats (dw/dw) treated with either recombinant human growth hormone or saline for 10 days. In addition, age-matched heterozygous (DW/dw) (normal weight and plasma IGF-I) control rats were treated with saline. Growth hormone increased weight gain from 0.1+/-0.1 (s.e.m) to 3.6+/-0.1 g/day and plasma IGF-I concentration from 364+/-23 to 451+/-32 ng/ml. Glucose metabolism in skeletal muscle perfused with basal, submaximal and maximal concentrations (0, 600 and 60 000 pmol/l respectively) of insulin was not changed by growth hormone. No change could be detected in the total number of glucose transporters (GLUT1 and GLUT4) in the skeletal muscles, except from a lower amount of GLUT4 in the soleus muscle in the heterozygous control group. However, at submaximal insulin concentrations, skeletal muscle glucose uptake and transport were significantly lower in the heterozygous control group compared with the growth hormone-deficient group. This could indicate either a direct long-term effect of growth hormone or more likely a secondary effect attributable to the difference in body weight (205.2+/-3.1 vs 361. 6+/-5.9 g for dwarf rats and heterozygous controls respectively), and thereby muscle fibre size, between the groups probably resulting in lower average interstitial insulin and glucose concentrations at a given plasma concentration in the heterozygous rats. It is concluded that restoration of subnormal growth hormone concentrations for 10 days has no effect on insulin-stimulated glucose metabolism in skeletal muscle in vitro.

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