This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Davey, H. W. Articles by Grattan, D. R. Search for Related Content PubMed PubMed Citation Articles by Davey, H. W. Articles by Grattan, D. R.

STAT5b Is Required for GH-Induced Liver Igf-I Gene Expression

AgResearch (H.W.D., T.X., M.J.M.), Ruakura Research Centre, Hamilton 2001, New Zealand; Department of Biology (T.X., R.J.W.), University of Waikato, Hamilton 2001, New Zealand; Division of Cell and Molecular Biology (D.J.W.), Department of Biology, Boston University, Boston, Massachusetts 02215; and Department of Anatomy and Structural Biology (D.R.G.), School of Medical Sciences, University of Otago, Dunedin 6001, New Zealand

Address all correspondence and requests for reprints to: Helen W. Davey, AgResearch, Ruakura Research Center, East Street Private Bag 3123, Hamilton, New Zealand. E-mail: helen.davey{at}agresearch.co.nz

	Abstract

Top Abstract Introduction Materials and Methods Results Discussion References

 
Although the increased expression of Igf-I in liver in response to GH is well characterized, the intracellular signaling pathways that mediate this effect have not been identified. Intracellular signaling molecules belonging to the Janus kinase-signal transducer and activator of transcription 5b (JAK2-STAT5b) pathway are activated by GH and have previously been shown to be required for sexually dimorphic body growth and the expression of liver cytochrome P450 proteins known to be regulated by the gender-specific temporal patterns of pituitary GH secretion. Here, we evaluate the role of STAT5b in GH activation of Igf-I by monitoring the induction of Igf-I mRNA in livers of wild-type and Stat5b^-/-mice stimulated with exogenous pulses of GH. GH induced the expression of liver Igf-I mRNA in hypophysectomized male wild-type, but not in hypophysectomized male Stat5b^-/- mice, although theStat5b^-/- mice exhibit both normal liver GH receptor expression and strong GH induction of Cytokine-inducible SH2 protein (Cis), which is believed to contribute to the down-regulation of GH-induced liver STAT5b signaling. Thus, STAT5b plays an important and specific role in liver Igf-I gene expression.

	Introduction

Top Abstract Introduction Materials and Methods Results Discussion References

 
THE EFFECTS OF GH on postnatal growth are mediated, at least in part, by the 70 amino acid peptide IGF-I, which is produced both in the liver (approximately 75% of total circulating IGF-I) and in peripheral tissues. Gene deletion studies have established that liver-derived IGF-I is dispensable for normal body growth, suggesting that IGF-I produced locally in peripheral tissues mediates the major effects of GH on postnatal growth (1, 2, 3, 4, 5, 6, 7) and that liver-derived IGF-I functions as a component of insulin action in peripheral tissues (8). However, the elevated plasma GH levels seen in liver IGF-I-deficient mice (8) may support growth via increased peripheral tissue expression of Igf-I, raising the possibility that liver-derived IGF-I may indeed help mediate the growth effects of GH under normal physiological conditions.

GH-stimulated dimerization of GH receptors on the cell surface of target tissues results in the activation of multiple intracellular signaling molecules, including MAP kinase, insulin receptor substrates, phosphoinositol 3'-phosphate kinase, diacylglycerol, PKC, intracellular calcium, and STAT signaling pathways (9, 10, 11). These intracellular factors mediate GH-stimulated changes in gene expression, and have diverse effects on growth and metabolism (11, 12, 13).

Although GH treatment of hypophysectomized rats induces Igf-I gene transcription within 30 min (14), the signaling pathways used by GH to activate Igf-I expression are unknown (11). One possibility is that GH-stimulated Igf-I expression is regulated by the JAK-STAT5b pathway, which we have shown to be required for sexually dimorphic body growth and also for the expression of the major urinary proteins and several cytochrome P450 enzymes in murine liver (15, 16). These well characterized gender differences in body growth and gene expression are particularly striking in rodents and result from the distinct temporal patterns of pituitary GH secretion that occur in males and females (17).

The availability of mice that are deficient in STAT5b has provided a simple in vivo model to test the hypothesis that GH-induced Igf-I expression is dependent on STAT5b signaling. In the present study, wild-type (WT) and Stat5b^-/- male mice were hypophysectomized to eliminate endogenous GH, and then GH was replaced by injections given twice daily. Expression of Igf-I mRNA was stimulated by GH in livers of WT, but not Stat5b^-/- mice, providing strong evidence for the involvement of STAT5b in GH-induced liver Igf-I gene expression.

	Materials and Methods

Top Abstract Introduction Materials and Methods Results Discussion References

 
Animals
Male 129 X BALB/c WT and Stat5b^-/- mice were hypophysectomized by the parapharyngeal route (18) at 4–17 wk of age and maintained on a 12-h light, 12-h dark schedule, with free access to food and drinking water (supplemented with 5% glucose wt/vol) for 8 wk. Bovine GH (2 µg per g body weight; American Cyanamid Co., Princeton, NJ) was then injected ip at 12-h intervals for 7 d. This protocol has previously been shown to reestablish male-specific gene expression patterns in GH-deficient mice (16, 19). No thyroxine was given before or during this experiment, although some mice had been treated for 1 wk for an independent experiment to measure major urinary protein expression (16), at least 2 wk before the GH treatment. There was no glucocorticoid replacement at any time. Liver tissue from 3-month-old intact male and female WT and Stat5b^-/- mice was also analyzed. Mice were killed by CO₂ asphyxiation (at similar times after GH injection for both WT and Stat5b^-/- mice), and livers were collected and frozen in liquid nitrogen. The experimental procedures were approved by the Ruakura Animal Ethics Committee acting in accordance with the guidelines of the New Zealand Animal Ethics Advisory Committee.

RNA isolation, Northern analysis, and quantitative PCR
Total RNA was extracted using TRIZOL (Life Technologies, Inc.). The RNA (15 µg) was fractionated on a 1% formaldehyde-agarose gel, then transferred and fixed to Hybond N⁺ (Amersham Pharmacia Biotech). cDNA probes were labeled with [-³²P]dCTP (Rediprime II labeling kit, Amersham Pharmacia Biotech). For Igf-I (ovine Igf-I cDNA, provided by Dr. E. A. Wong, Virginia Polytechnic Institute and State University), the hybridization was at 60 C for 7 h (20), and the membrane was washed at 60 C to 0.5x SSC, 0.1% SDS. For probings for expression of GH receptor (ovine Ghr cDNA provided by Dr. T. E. Adams, CSIRO, Parkville, Australia), Cis (mouse cDNA provided by Dr. D. J. Hilton, The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia) and ß actin (21), the Super Hyb kit was used (Molecular Research Center, Inc., Cincinnati, OH). Membranes were exposed to X-OMAT AR film with an intensifying screen at -80 C.

In addition to Northern analyses, we used the ABI Prism 7700 Sequence Detection System (Applied Biosystems) to quantify relative levels of gene expression. TaqMan probes and primers were designed for murine Igf-I, GH receptor (Ghr) and glyceraldehyde-3-phosphate dehydrogenase (Gapdh) mRNA transcripts, and were used to measure the relative amounts of these mRNAs in liver tissue by real-time quantitative RT-PCR. To detect Igf-I transcripts, the probe and primers were designed to detect exons 3 and 4, which are common to all Igf-I mRNAs (22, 23) (mIgf-I probe 5' CTC CAG CAT TCG GAG GGC ACC TC 3'; forward primer 5' CTT CAA CAA GCC CAC AGG CTA T 3'; reverse primer 5' GCT CCG GAA GCA ACA CTC AT 3'). For GH receptor mRNA, the primers and probe were designed to detect exons 7 and 8 (mGhr-probe 5' CAC ATG CTT CCA ATA TGT TCG TCT GAG GAA 3'; forward primer 5' TTC AGC GAA GTC CTC CGT GTA 3'; reverse primer 5' AGA ACC ATG GAA ACT GGA TAT CTT CT 3'). GH binding protein mRNA, which is derived from splicing of an alternative 8A exon (24, 25) is not amplified using these primers, and genomic DNA sequences are not amplified efficiently because the primers span intron sequences. Reverse transcriptase (Superscript II, Life Technologies, Inc.) was used to synthesize cDNA before PCR. Control reactions without reverse transcriptase were included in the assays to ensure that DNA, including pseudogene sequences, did not contribute to the quantification results. Gapdh was used to normalize differences in the amounts of template RNA used in the TaqMan assays (mGapdh probe 5'-TGG AAG GGC TCA TGA CCA CAG TCC A-3'; Forward primer 5' TGC ACC ACC AAC TGC TTA GC 3'; Reverse primer 5' GTC TTC TGG GTG GCA GTG ATG 3'). Universal PCR Master Mix (PE Applied Biosystems) was used in these studies. The concentration of primers and probe were 300 nM and 200 nM, respectively. The PCR program was 50 C for 2 min; 95 C for 10 min; then 40 cycles of 95 C for 15 sec and 60 C for 1 min.

The relative amounts of mRNA were calculated from the threshold cycle numbers, and are presented relative to the amounts of mRNA in one sample that is arbitrarily set at one. The threshold cycle is the first PCR cycle for which there is a statistically significant increase in fluorescence resulting from the 5' nuclease activity of the AmpliTaq Gold DNA polymerase. The fluorescence increases exponentially with the amount of PCR product and the threshold cycle reflects the amount of target RNA or DNA in the sample (i.e. more target results in a lower threshold cycle). The threshold cycle for Gapdh was used to standardize the amount of sample RNA in the reaction i.e. the difference in the threshold cycles for Igf-I or Ghr and Gapdh mRNA was used to calculate the relative amounts of Igf-I or Ghr mRNAs in each sample.

Serum IGF-1 assay
Mouse serum IGF-I concentrations were measured after acid-ethanol cryoprecipitation using a RIA, as previously described (26).

Statistical analysis
Serum IGF-I concentrations were analyzed by ANOVA of the log transformed concentrations, using Minitab Release 12 (Minitab Inc., State College, PA). The results are presented as the backtransformed geometric means.

TaqMan mRNA data are presented as the means and SEMs. The PCR threshold cycle differences were transformed using 2^value to determine the relative levels of mRNA expression (because there is a 2-fold exponential increase in the amount of DNA product/fluorescence following each PCR cycle). Levels of significance were calculated by ANOVA using Minitab Release 12. t tests were also used to make comparisons between two groups where appropriate.

	Results

Top Abstract Introduction Materials and Methods Results Discussion References

 
Completeness of hypophysectomy
Several criteria were used to confirm that the pituitaries were successfully removed. These included a marked reduction in the excretion of major urinary proteins in urine (measured 2 and 8 wk following surgery), low serum PRL concentrations, the absence of the pituitaries on post mortem inspection of the base of the skull, and the absence of body growth (18) (data not shown). Following hypophysectomy, the body weights of the mice did not increase; even young mice that weighed about 15 g remained at this weight. A few of the older mice (>30 g) lost weight immediately following hypophysectomy, but there was no apparent difference between WT and Stat5b^-/- mice.

Liver Igf-I mRNA is induced by GH in hypophysectomized WT but not hypophysectomized Stat5b^-/- mice.
The levels of Igf-I mRNA in the livers of intact male and female WT and Stat5b^-/- mice, and in male hypophysectomized WT and Stat5b^-/-mice either with or without GH replacement were determined using real-time quantitative PCR (Fig. 1A) and Northern blot analysis (Fig. 1B). STAT5b deficiency, in itself, resulted in a 50% reduction (P < 0.01, t test) in the average Igf-I mRNA in the liver (Fig. 1A). Following hypophysectomy, the levels of Igf-I dropped dramatically, in both WT and Stat5b^-/-male mice, to 8% and 1.3% of the levels found in intact WT mice. GH injection twice daily for 7 d induced the expression of Igf-I mRNA in hypophysectomized WT mice to levels that were similar to the intact WT mice. By contrast, in hypophysectomized Stat5b^-/- mice there was no significant increase in liver Igf-I mRNA in response to GH (Fig. 1A).

View larger version (42K): [in this window] [in a new window]   Figure 1. A, Relative levels of Igf-I mRNA in livers of WT and Stat5b-/- (knockout; KO) mice, and in hypophysectomized (Hx) male mice that were untreated (-) or injected with bGH (+) every 12 h for 7 d as described under Materials and Methods. TaqMan real-time RT-PCR was used to quantify the indicated mRNAs in six to nine mice per group. The mRNA levels reported are normalized to Gapdh mRNA levels, and are expressed relative to the level in untreated hypophysectomized male Stat5b-/- mice. Differences between the means in the ANOVA, are indicated by letters. a and b differ from d (P < 0.001); a differs from c (P < 0.05). In separate analyses using t test, Igf-I mRNA was found to be higher (P < 0.01) in both male and female intact WT vs. intact Stat5b-/- mice. B, Northern blot analysis of Igf-I mRNA in individual hypophysectomized male mice. Total RNA (15 µg) was separated on a 1% agarose gel, transferred to a nylon membrane and probed with radioactively labeled cDNA probe. The Igf-I cDNA hybridized to mRNA transcripts of 0.9–1.2, 1.5–1.9, and 7.0–7.5 kb. C, The ethidium bromide stained agarose gel before northern blotting, showing the consistency of the 28S and 18S rRNAs.

Serum IGF-I levels follow similar trends to liver mRNA levels
Stat5b^-/- mice have about 30% lower levels of serum IGF-I compared with WT mice (15). As expected, hypophysectomy greatly reduced serum IGF-I levels in both WT and Stat5b^-/- mice (Table 1). Pulsatile GH replacement for 7 d stimulated a dramatic 13-fold increase in serum IGF-I in hypophysectomized WT mice (P < 0.001). By contrast, in hypophysectomized Stat5b^-/- mice, GH replacement stimulated a very small increase in serum IGF-I (P < 0.05) (Table 1). The GH-induced IGF-I level in hypophysectomized WT mice, corresponds to a 79% restoration of the IGF-I levels that we previously reported in WT intact mice (15).

View larger version (48K): [in this window] [in a new window]   Figure 2. A, Relative levels of Ghr mRNA in livers of WT (WT) and Stat5b-/- (KO) mice and in hypophysectomized (Hx) male mice that were untreated (-) or treated for 7 d with GH (+) as described in Materials and Methods. TaqMan real-time RT-PCR was used to quantify the indicated mRNAs in six to nine mice per group. The mRNA levels reported are normalized to Gapdh mRNA levels and are expressed relative to the level in untreated hypophysectomized male Stat5b-/- mice. Differences between the means are indicated by letters. a differs from b (P < 0.01). B, GH receptor mRNA in individual hypophysectomized male WT (WT) and Stat5b-/- (KO) mice. Total RNA (15 µg) was electrophoresed on a 1% denaturing agarose gel, transferred to nylon membrane and hybridized with radiolabeled Ghr cDNA. The membrane was exposed to X-OMAT-AR film. C, Northern blot from B, stripped and reprobed with a human ß actin cDNA probe.

View larger version (32K): [in this window] [in a new window]   Figure 3. Cis mRNA in individual hypophysectomized male WT and Stat5b-/- (KO) mice. Total RNA (15 µg) was electrophoresed on a 1% denaturing agarose gel, transferred to nylon membrane and hybridized with radiolabeled Cis cDNA. The membrane was exposed to X-OMAT-AR film.

	Discussion

Top Abstract Introduction Materials and Methods Results Discussion References

GH rapidly and transiently stimulates transcription of Igf-I in liver in vivo (14, 29) and activates a number of intracellular signaling pathways (11, 13) including those mediated by STATs 1, 3, 5a, and 5b (9, 10, 30, 31, 32). However, the relative importance of these events for GH-induced Igf-I gene expression was not previously resolved by these, or other, experiments (33, 34). Serum IGF-I levels are dramatically reduced in hypophysectomized rats, to about 5% of those found in intact rats, and these low basal levels have facilitated studies of the kinetics of GH-induced Igf-I expression. Using this model, a single injection of GH increases Igf-I transcription within 30 min (14). In the present study, we also used hypophysectomy to eliminate endogenous GH and circulating IGF-I. The induction of liver Igf-I mRNA in WT, but not in Stat5b^-/- mice following GH replacement provides a simple demonstration of the requirement for STAT5b in the GH-induced expression of Igf-I in hypophysectomized mice. This requirement of STAT5b for GH pulse stimulation of Igf-I (this study) and male-specific liver cytochrome P450s seen earlier (16) does not reflect a generalized loss of GH signaling, as evidenced by the GH-inducible expression of Cis mRNA in the same mice (Fig. 3).

The present demonstration that STAT5b plays a role in liver Igf-I expression raises several questions. The average level of liver Igf-I mRNA in intact Stat5b^-/- mice was 50% of that in WT mice, which is in agreement with our finding that Stat5b^-/- mice have serum IGF-I levels that are approximately 30% lower than WT mice (15). This result would not be predicted, however, if the sole signaling pathway for expressing Igf-I was via GH activation of STAT5b. The dramatic reduction in serum IGF-I levels seen in hypophysectomized Stat5b^-/- mice (Table 1) indicates that factors secreted by or regulated by the pituitary gland play an important role in maintaining serum IGF-I in a STAT5b-independent manner. That GH is primarily responsible for Igf-I expression is indicated by the near complete restoration of serum IGF-I in response to GH treatment of WT hypophysectomized mice. One possible explanation for these observations is that compensatory mechanisms, involving pituitary-derived factors other than GH, operate in intact but not hypophysectomized Stat5b^-/- mice, resulting in substantial expression of Igf-I in liver, and consequently maintenance of plasma levels of IGF-I despite the absence of STAT5b. There is also indirect evidence that pituitary GH secretion may be elevated in Stat5b^-/- mice (15, 35), which may stimulate Igf-I expression in peripheral tissues by a STAT5b-independent pathway perhaps involving STAT5a.

A further question is whether GH acts directly to activate Igf-I gene expression via the JAK-STAT5b pathway, or whether GH-activated STAT5b operates via an indirect mechanism to induce Igf-I gene expression. GH has an immediate effect on Igf-I gene transcription in WT hypophysectomized rats (14). However, whereas there may be a direct action of GH on Igf-I transcription in the present experiments, the STAT5b requirement for Igf-I expression may nevertheless be an indirect one, i.e. STAT5b may not directly activate Igf-I gene transcription by directly binding to the promoter or interacting in transcription complexes. STAT5 DNA-binding consensus elements have not been identified in rodent Igf-I 5' flanking DNA sequences, but the analysis has not been extensive. Moreover, STAT5 tetramers have the ability to bind to adjacent weak consensus elements that are not revealed in a search for standard STAT5 consensus sequences (36). Further investigation, including a more detailed analysis of Igf-I gene regulatory elements, and a determination of whether a single pulse of GH stimulates a rapid increase in Igf-I mRNA in hypophysectomized WT but not Stat5b^-/- mice, will be required to establish the precise role of the STAT5b pathway in GH-induced liver Igf-I gene expression.

Also of interest is whether STAT5b is specifically required for Igf-I gene expression, or whether STAT5a, which shares 92% amino acid identity with STAT5b, acts equivalently in this regard. Greater than 90% of the Stat5 mRNA in liver is Stat5b (37), and thus Stat5b^-/- mice are estimated to have dramatically lower levels of STAT5 per se than WT mice. Liver STAT5a protein levels are not altered by Stat5b gene disruption or by hypophysectomy of the Stat5b^-/- mice (16) and because the pattern of STAT5a activation in the liver is similar to that for STAT5b (37, 38), the reduced amounts of total STAT5 protein, rather than the loss of STAT5b per se, could explain the lack of GH-induced Igf-I mRNA in the livers of hypophysectomized Stat5b^-/- mice.

GH treatment of hypophysectomized Stat5b^-/- mice stimulated a modest increase in serum IGF-I levels (P < 0.05), which was greater than the increase in liver Igf-I mRNA levels. This proportionally greater increase in serum IGF-I may reflect changes in extrahepatic IGF-I production, as well as changes in other GH-regulated factors that modulate plasma IGF-I, such as IGFBP3 and the acid labile subunit ALS (39), that may, at least in part, be independent of STAT5b. Alternatively, as in intact Stat5b^-/- mice, a portion of serum IGF-I may be derived from GH-JAK2 signaling mediated by STAT5a, which is activated in hypophysectomized Stat5b^-/- mice by GH treatment (16). This latter observation, together with the induction of Cis expression in the livers of GH-treated hypophysectomized Stat5b^-/- mice noted above, provides clear evidence for a functional GH receptor/JAK2 pathway in these mice. Accordingly, defects in these components can be ruled out as the basis for the unresponsiveness of the Igf-I gene (Fig. 1) and the sexually dimorphic liver cytochrome P450s (16), to GH pulse stimulation in Stat5b^-/- mice.

In conclusion, our data provides strong evidence for STAT5b playing an important role in liver Igf-I expression.

	Acknowledgments

 
We thank Dr. P. K. Lund (University of North Carolina at Chapel Hill) for encouraging us to do this work, Dr. B. H. Breier (University of Auckland) for performing the IGF-I assays and Simrana Clayton for the technical assistance. We also thank American Cyanamid Co. for providing the bGH. Special thanks to Ric Broadhurst for assistance with anesthesia and surgery, Glenda Smith and Bobby Smith for care of the mice, and Harold Henderson for statistical advice.

	Footnotes

 
This work was funded by the New Zealand Marsden Fund (H.W.D., R.J.W.) and by the U.S. National Institutes of Health, Grant DK-33765 (D.J.W.)

Abbreviations: Hx, Hypophysectomized; KO, knockout; WT, wild-type.

Received February 15, 2001.

Accepted for publication May 31, 2001.

	References

Top Abstract Introduction Materials and Methods Results Discussion References

 

1. Daughday WH, Hall K, Raben MS, Salmon Jr WD, Van der Brande JL, Van Wyk JJ 1972 Somatomedin: proposed designation for sulphation factor. Nature 235:107[CrossRef][Medline]
2. Baker J, Liu J-P, Robertson EJ, Efstradiadis A 1993 Role of insulin-like growth factors in embryonic and postnatal growth. Cell 75:73–82[CrossRef][Medline]
3. Liu J-P, Baker J, Perkins AS, Robertson EJ, Efstradiadis A 1993 Mice carrying null mutations of the genes encoding insulin-like growth factor I (Igf-I) and type I IGF receptor (IgfIr). Cell 75:59–72[Medline]
4. Liu JL, Le Roith D 1999 Insulin-like growth factor I is essential for postnatal growth in response to growth hormone. Endocrinology 140:5178–5184[Abstract/Free Full Text]
5. Sjogren K, Liu JL, Blad K, et al. 1999 Liver-derived insulin-like growth factor I (IGF-I) is the principal source of IGF-I in blood but is not required for postnatal body growth in mice. Proc Natl Acad Sci USA 96:7088–7092[Abstract/Free Full Text]
6. Yakar S, Liu JL, Stannard B, et al. 1999 Normal growth and development in the absence of hepatic insulin-like growth factor I. Proc Natl Acad Sci USA 96:7324–7329[Abstract/Free Full Text]
7. Le Roith D, Bondy C, Yakar S, Liu JL, Butler A 2001 The somatomedin hypothesis: 2001. Endocr Rev 22:53–74[Abstract/Free Full Text]
8. Yakar S, Liu JL, Fernandez AM, et al. 2001 Liver-specific Igf-1 gene deletion leads to muscle insulin insensitivity. Diabetes 50:1110–1118[Abstract/Free Full Text]
9. Meyer DJ, Campbell GS, Cochran BH, et al. 1994 Growth hormone induces a DNA binding factor related to the interferon-stimulated 91-kDa transcription factor. J Biol Chem 269:4701–4704[Abstract/Free Full Text]
10. Gronowski AM, Rotwein P 1994 Rapid changes in nuclear protein tyrosine phosphorylation after growth hormone treatment in vivo. Identification of phosphorylated mitogen-activated protein kinase and STAT91. J Biol Chem 269:7874–7878[Abstract/Free Full Text]
11. Carter-Su C, Smit LS 1998 Signaling via JAK tyrosine kinases: growth hormone receptor as a model system. Recent Prog Horm Res 53:61–82
12. Isaksson OGP, Eden S, Jansson J-O 1985 Mode of action of pituitary growth hormone on target cells. Annu Rev Physiol 47:483–499[CrossRef][Medline]
13. Waxman DJ, Frank SJ 2000 Principles of molecular regulation. In: Cohen PM, Means AR, eds. Totawa, NJ: Humana Press; 55–83
14. Bichell DP, Kikuchi K, Rotwein P 1992 Growth hormone rapidly activates insulin-like growth factor I gene transcription in vivo. Mol Endocrinol 6:1899–1908[Abstract/Free Full Text]
15. Udy GB, Towers RP, Snell RG, et al. 1997 Requirement of STAT5b for sexual dimorphism of body growth rates and liver gene expression. Proc Natl Acad Sci USA 94:7239–7244[Abstract/Free Full Text]
16. Davey HW, Park SH, Grattan DR, McLachlan MJ, Waxman DJ 1999 STAT5b-deficient mice are growth hormone pulse-resistant—role of STAT5b in sex-specific liver P450 expression. J Biol Chem 274:35331–35336[Abstract/Free Full Text]
17. Davey HW, Wilkins RJ, Waxman DJ 1999 STAT5 signaling in sexually dimorphic gene expression and growth patterns. Am J Hum Genet 65:959–965[CrossRef][Medline]
18. Averill RLW, Grattan DR, Norris SK 1991 Posterior pituitary lobectomy chronically attenuates the nocturnal surge of prolactin in early pregnancy. Endocrinology 128:705–709[Abstract/Free Full Text]
19. Noshiro M, Negishi M 1986 Pretranslational regulation of sex-dependent testosterone hydroxylases by growth hormone in mouse liver. J Biol Chem 261:15923–15927[Abstract/Free Full Text]
20. Church GM, Gilbert W 1984 Genomic sequencing. Proc Natl Acad Sci USA 81:1991–1995[Abstract/Free Full Text]
21. Erba HP, Gunning P, Kedes L 1986 Nucleotide sequence of the human cytoskeletal actin mRNA: anomalous evolution of vertebrate non-muscle actin genes. Nucleic Acids Res 14:5275–5294[Abstract/Free Full Text]
22. Lund PK 1999 Insulin-like growth factors: gene structure and regulation. In: Goodman HM, ed. Handbook of physiology. A critical, comprehensive presentation of physiological knowledge and concepts. Vol V: Hormonal control of growth. New York: Oxford University Press; 537–571
23. Rotwein P 1991 Structure, evolution, expression and regulation of insulin-like growth factors I and II. Growth Factors 5:3–18[Medline]
24. Edens A, Southard JN, Talamantes F 1994 Mouse growth hormone-binding protein and growth hormone receptor transcripts are produced from a single gene by alternative splicing. Endocrinology 135:2802–2805[Abstract]
25. Moffat JG, Edens A, Talamantes F 1999 Structure and expression of the mouse growth hormone receptor/growth hormone binding protein gene. J Mol Endocrinol 23:33–44[Abstract]
26. Breier BH, Vickers MH, Gravance CG, Casey PJ 1996 Growth hormone (GH) therapy markedly increases the motility of spermatozoa and the concentration of insulin-like growth factor-I in seminal vesicle fluid in the male GH-deficient dwarf rat. Endocrinology 137:4061–4064[Abstract]
27. Davey HW, McLachlan MJ, Wilkins RJ, Hilton DJ, Adams TE 1999 STAT5b mediates the GH-induced expression of SOCS-2 and SOCS-3 mRNA in the liver. Mol Cell Endocrinol 158:111–116[CrossRef][Medline]
28. Teglund S, McKay C, Schuetz E et al. 1998 Stat5a and Stat5b proteins have essential and nonessential, or redundant, roles in cytokine responses. Cell 93:841–850[CrossRef][Medline]
29. Thomas MJ, Kikuchi K, Bichell DP, Rotwein P 1994 Rapid activation of rat insulin-like growth factor-I gene transcription by growth hormone reveals no alterations in deoxyribonucleic acid-protein interactions within the major late promoter. Endocrinology 135:1584–1592[Abstract]
30. Gronowski AM, Zhong Z, Wen Z, Thomas MJ, Darnell Jr JE, Rotwein P 1995 In vivo growth hormone treatment rapidly stimulates the tyrosine phosphorylation and activation of Stat3. Mol Endocrinol 9:171–177[Abstract/Free Full Text]
31. Ram PA, Park S-H, Choi HK, Waxman DJ 1996 Growth hormone activation of Stat 1, Stat 3, and Stat 5 in rat liver. J Biol Chem 271:5929–5940[Abstract/Free Full Text]
32. Waxman DJ, Ram PA, Park S-H, Choi HK 1995 Intermittent plasma growth hormone triggers tyrosine phosphorylation and nuclear translocation of a liver-expressed, STAT5-related DNA binding protein. J Biol Chem 270: 13262–13270
33. Meton I, Boot EPJ, Sussenbach JS, Steenbergh PH 1999 Growth hormone induces insulin-like growth factor-I gene transcription by synergistic action of STAT5 and HNF-1. FEBS Lett 444:155–159[CrossRef][Medline]
34. Benbassat C, Shoba LNN, Newman M, Adamo ML, Frank SJ, Lowe WL 1999 Growth hormone-mediated regulation of insulin-like growth factor I promoter activity in C6 glioma cells. Endocrinology 140:3073–3081[Abstract/Free Full Text]
35. Luckman SM, McGuiness L, Thomas GB, Robinson ICAF, Udy GB, Davey HW 1998 Signal transducer and activator of transcription, STAT5b, and growth hormone (GH) feedback on somatostatin (SOM) neurons. Society for Neuroscience (Abstract)
36. Soldaini E, John S, Moro S, Bollenbacher J, Schindler U, Leonard WJ 2000 DNA binding site selection of dimeric and tetrameric Stat5 proteins reveals a large repertoire of divergent tetrameric Stat5a binding sites. Mol Cell Biol 20:389–401[Abstract/Free Full Text]
37. Park SH, Liu X, Hennighausen L, Davey HW, Waxman DJ 1999 Distinctive roles of STAT5a and STAT5b in sexual dimorphism of hepatic P450 gene expression. Impact of STAT5a gene disruption. J Biol Chem 274:7421–7430[Abstract/Free Full Text]
38. Choi HK, Waxman DJ 1999 Continuous GH, but not prolactin, maintains low-level activation of STAT5a and STAT5b in female rat liver. Endocrinology 140:5126–5135[Abstract/Free Full Text]
39. Ooi GT, Cohen FJ, Tseng LY, Rechler MM, Boisclair YR 1997 Growth hormone stimulates transcription of the gene encoding the acid-labile subunit (ALS) of the circulating insulin-like growth factor-binding protein complex and ALS promoter activity in rat liver. Mol Endocrinol 11:997–1007[Abstract/Free Full Text]

This article has been cited by other articles:

				P. Klover, W. Chen, B.-M. Zhu, and L. Hennighausen Skeletal muscle growth and fiber composition in mice are regulated through the transcription factors STAT5a/b: linking growth hormone to the androgen receptor FASEB J, September 1, 2009; 23(9): 3140 - 3148. [Abstract] [Full Text] [PDF]

				D. J. Waxman and M. G. Holloway Sex Differences in the Expression of Hepatic Drug Metabolizing Enzymes Mol. Pharmacol., August 1, 2009; 76(2): 215 - 228. [Abstract] [Full Text] [PDF]

				X. Wang, N. Yang, L. Deng, X. Li, J. Jiang, Y. Gan, and S. J. Frank Interruption of Growth Hormone Signaling via SHC and ERK in 3T3-F442A Preadipocytes upon Knockdown of Insulin Receptor Substrate-1 Mol. Endocrinol., April 1, 2009; 23(4): 486 - 496. [Abstract] [Full Text] [PDF]

				J. M. Oldham, C. C. Osepchook, F. Jeanplong, S. J. Falconer, K. G. Matthews, J. V. Conaglen, D. F. Gerrard, H. K. Smith, R. J. Wilkins, J. J. Bass, et al. The decrease in mature myostatin protein in male skeletal muscle is developmentally regulated by growth hormone J. Physiol., February 1, 2009; 587(3): 669 - 677. [Abstract] [Full Text] [PDF]

				M. D. Buzzelli, M. Nagarajan, J. F. Radtka, M. L. Shumate, M. Navaratnarajah, C. H. Lang, and R. N. Cooney Nuclear Factor-{kappa}B Mediates the Inhibitory Effects of Tumor Necrosis Factor-{alpha} on Growth Hormone-Inducible Gene Expression in Liver Endocrinology, December 1, 2008; 149(12): 6378 - 6388. [Abstract] [Full Text] [PDF]

				M. Wang, M. Chen, G. Zheng, B. Dillard, M. Tallarico, Z. Ortiz, and A.-X. Holterman Transcriptional activation by growth hormone of HNF-6-regulated hepatic genes, a potential mechanism for improved liver repair during biliary injury in mice Am J Physiol Gastrointest Liver Physiol, August 1, 2008; 295(2): G357 - G366. [Abstract] [Full Text] [PDF]

				S. Eleswarapu, Z. Gu, and H. Jiang Growth Hormone Regulation of Insulin-Like Growth Factor-I Gene Expression May Be Mediated by Multiple Distal Signal Transducer and Activator of Transcription 5 Binding Sites Endocrinology, May 1, 2008; 149(5): 2230 - 2240. [Abstract] [Full Text] [PDF]

				H. Jiang, Y. Wang, M. Wu, Z. Gu, S. J. Frank, and R. Torres-Diaz Growth Hormone Stimulates Hepatic Expression of Bovine Growth Hormone Receptor Messenger Ribonucleic Acid through Signal Transducer and Activator of Transcription 5 Activation of a Major Growth Hormone Receptor Gene Promoter Endocrinology, July 1, 2007; 148(7): 3307 - 3315. [Abstract] [Full Text] [PDF]

				T. A. Ahmed, M. D. Buzzelli, C. H. Lang, J. B. Capen, M. L. Shumate, M. Navaratnarajah, M. Nagarajan, and R. N. Cooney Interleukin-6 inhibits growth hormone-mediated gene expression in hepatocytes Am J Physiol Gastrointest Liver Physiol, June 1, 2007; 292(6): G1793 - G1803. [Abstract] [Full Text] [PDF]

				M. G. Holloway, Y. Cui, E. V. Laz, A. Hosui, L. Hennighausen, and D. J. Waxman Loss of Sexually Dimorphic Liver Gene Expression upon Hepatocyte-Specific Deletion of Stat5a-Stat5b Locus Endocrinology, May 1, 2007; 148(5): 1977 - 1986. [Abstract] [Full Text] [PDF]

				S. J. Frank Growth Hormone, Insulin-Like Growth Factor I, and Growth: Local Knowledge Endocrinology, April 1, 2007; 148(4): 1486 - 1488. [Full Text] [PDF]

				P. Klover and L. Hennighausen Postnatal Body Growth Is Dependent on the Transcription Factors Signal Transducers and Activators of Transcription 5a/b in Muscle: A Role for Autocrine/Paracrine Insulin-Like Growth Factor I Endocrinology, April 1, 2007; 148(4): 1489 - 1497. [Abstract] [Full Text] [PDF]

				X Han, N Benight, B Osuntokun, K Loesch, S J Frank, and L A Denson Tumour necrosis factor {alpha} blockade induces an anti-inflammatory growth hormone signalling pathway in experimental colitis Gut, January 1, 2007; 56(1): 73 - 81. [Abstract] [Full Text] [PDF]

				X. Han, B. Osuntokun, N. Benight, K. Loesch, S. J. Frank, and L. A. Denson Signal Transducer and Activator of Transcription 5b Promotes Mucosal Tolerance in Pediatric Crohn's Disease and Murine Colitis Am. J. Pathol., December 1, 2006; 169(6): 1999 - 2013. [Abstract] [Full Text] [PDF]

				S. J. Frank, X. Wang, K. He, N. Yang, P. Fang, R. G. Rosenfeld, V. Hwa, T. R. Chaudhuri, L. Deng, and K. R. Zinn In Vivo Imaging of Hepatic Growth Hormone Signaling Mol. Endocrinol., November 1, 2006; 20(11): 2819 - 2830. [Abstract] [Full Text] [PDF]

				T. Ahmed, G. Yumet, M. Shumate, C. H. Lang, P. Rotwein, and R. N. Cooney Tumor necrosis factor inhibits growth hormone-mediated gene expression in hepatocytes Am J Physiol Gastrointest Liver Physiol, July 1, 2006; 291(1): G35 - G44. [Abstract] [Full Text] [PDF]

				K. H. Clodfelter, M. G. Holloway, P. Hodor, S.-H. Park, W. J. Ray, and D. J. Waxman Sex-Dependent Liver Gene Expression Is Extensive and Largely Dependent upon Signal Transducer and Activator of Transcription 5b (STAT5b): STAT5b-Dependent Activation of Male Genes and Repression of Female Genes Revealed by Microarray Analysis Mol. Endocrinol., June 1, 2006; 20(6): 1333 - 1351. [Abstract] [Full Text] [PDF]

				C. Z. Michaylira, N. M. Ramocki, J. G. Simmons, C. K. Tanner, K. K. McNaughton, J. T. Woosley, C. J. Greenhalgh, and P. K. Lund Haplotype Insufficiency for Suppressor of Cytokine Signaling-2 Enhances Intestinal Growth and Promotes Polyp Formation in Growth Hormone-Transgenic Mice Endocrinology, April 1, 2006; 147(4): 1632 - 1641. [Abstract] [Full Text] [PDF]

				A. Flores-Morales, C. J. Greenhalgh, G. Norstedt, and E. Rico-Bautista Negative Regulation of Growth Hormone Receptor Signaling Mol. Endocrinol., February 1, 2006; 20(2): 241 - 253. [Abstract] [Full Text] [PDF]

				J. E. Rowland, L. M. Kerr, M. White, P. G. Noakes, and M. J. Waters Heterozygote Effects in Mice with Partial Truncations in the Growth Hormone Receptor Cytoplasmic Domain: Assessment of Growth Parameters and Phenotype Endocrinology, December 1, 2005; 146(12): 5278 - 5286. [Abstract] [Full Text] [PDF]

				K. He, K. Loesch, J. W. Cowan, X. Li, L. Deng, X. Wang, J. Jiang, and S. J. Frank Janus Kinase 2 Enhances the Stability of the Mature Growth Hormone Receptor Endocrinology, November 1, 2005; 146(11): 4755 - 4765. [Abstract] [Full Text] [PDF]

				M. L. Shumate, G. Yumet, T. A. Ahmed, and R. N. Cooney Interleukin-1 inhibits the induction of insulin-like growth factor-I by growth hormone in CWSV-1 hepatocytes Am J Physiol Gastrointest Liver Physiol, August 1, 2005; 289(2): G227 - G239. [Abstract] [Full Text] [PDF]

				M. A. Held, W. Cosme-Blanco, L. M. Difedele, E. L. Bonkowski, R. K. Menon, and L. A. Denson Alterations in growth hormone receptor abundance regulate growth hormone signaling in murine obstructive cholestasis Am J Physiol Gastrointest Liver Physiol, May 1, 2005; 288(5): G986 - G993. [Abstract] [Full Text] [PDF]

				Y. Wang and H. Jiang Identification of a Distal STAT5-binding DNA Region That May Mediate Growth Hormone Regulation of Insulin-like Growth Factor-I Gene Expression J. Biol. Chem., March 25, 2005; 280(12): 10955 - 10963. [Abstract] [Full Text] [PDF]

				F. Haddad, F. Zaldivar, D. M. Cooper, and G. R. Adams IL-6-induced skeletal muscle atrophy J Appl Physiol, March 1, 2005; 98(3): 911 - 917. [Abstract] [Full Text] [PDF]

				J. E. Rowland, A. M. Lichanska, L. M. Kerr, M. White, E. M. d'Aniello, S. L. Maher, R. Brown, R. D. Teasdale, P. G. Noakes, and M. J. Waters In Vivo Analysis of Growth Hormone Receptor Signaling Domains and Their Associated Transcripts Mol. Cell. Biol., January 1, 2005; 25(1): 66 - 77. [Abstract] [Full Text] [PDF]

				D. F. Sun, Z. Zheng, P. Tummala, J. Oh, F. Schaefer, and R. Rabkin Chronic Uremia Attenuates Growth Hormone-Induced Signal Transduction in Skeletal Muscle J. Am. Soc. Nephrol., October 1, 2004; 15(10): 2630 - 2636. [Abstract] [Full Text] [PDF]

				Y. Huang, S.-O. Kim, N. Yang, J. Jiang, and S. J. Frank Physical and Functional Interaction of Growth Hormone and Insulin-Like Growth Factor-I Signaling Elements Mol. Endocrinol., June 1, 2004; 18(6): 1471 - 1485. [Abstract] [Full Text] [PDF]

				R. P. Rhoads, J. W. Kim, B. J. Leury, L. H. Baumgard, N. Segoale, S. J. Frank, D. E. Bauman, and Y. R. Boisclair Insulin Increases the Abundance of the Growth Hormone Receptor in Liver and Adipose Tissue of Periparturient Dairy Cows J. Nutr., May 1, 2004; 134(5): 1020 - 1027. [Abstract] [Full Text] [PDF]

				M. D. Lewis, M. Horan, D. S. Millar, V. Newsway, T. E. Easter, L. Fryklund, J. W. Gregory, M. Norin, C.-J. Del Valle, J. P. Lopez-Siguero, et al. A Novel Dysfunctional Growth Hormone Variant (Ile179Met) Exhibits a Decreased Ability to Activate the Extracellular Signal-Regulated Kinase Pathway J. Clin. Endocrinol. Metab., March 1, 2004; 89(3): 1068 - 1075. [Abstract] [Full Text] [PDF]

				V. Hwa, B. Little, E. M. Kofoed, and R. G. Rosenfeld Transcriptional Regulation of Insulin-like Growth Factor-I by Interferon-{gamma} Requires STAT-5b J. Biol. Chem., January 23, 2004; 279(4): 2728 - 2736. [Abstract] [Full Text] [PDF]

				H. Yoshizato, M. Tanaka, N. Nakai, N. Nakao, and K. Nakashima Growth Hormone (GH)-Stimulated Insulin-Like Growth Factor I Gene Expression Is Mediated by a Tyrosine Phosphorylation Pathway Depending on C-Terminal Region of Human GH Receptor in Human GH Receptor-Expressing Ba/F3 Cells Endocrinology, January 1, 2004; 145(1): 214 - 220. [Abstract] [Full Text] [PDF]

				L. Q. Hong-Brown, C. R. Brown, R. N. Cooney, R. A. Frost, and C. H. Lang Sepsis-induced muscle growth hormone resistance occurs independently of STAT5 phosphorylation Am J Physiol Endocrinol Metab, July 1, 2003; 285(1): E63 - E72. [Abstract] [Full Text] [PDF]

				J. Woelfle, J. Billiard, and P. Rotwein Acute Control of Insulin-like Growth Factor-I Gene Transcription by Growth Hormone through Stat5b J. Biol. Chem., June 13, 2003; 278(25): 22696 - 22702. [Abstract] [Full Text] [PDF]

				N. Balthasar, P.-F. Mery, C. B. Magoulas, K. E. Mathers, A. Martin, P. Mollard, and I. C. A. F. Robinson Growth Hormone-Releasing Hormone (GHRH) Neurons in GHRH-Enhanced Green Fluorescent Protein Transgenic Mice: A Ventral Hypothalamic Network Endocrinology, June 1, 2003; 144(6): 2728 - 2740. [Abstract] [Full Text] [PDF]

				Y. Huang, S.-O. Kim, J. Jiang, and S. J. Frank Growth Hormone-induced Phosphorylation of Epidermal Growth Factor (EGF) Receptor in 3T3-F442A Cells: MODULATION OF EGF-INDUCED TRAFFICKING AND SIGNALING J. Biol. Chem., May 23, 2003; 278(21): 18902 - 18913. [Abstract] [Full Text] [PDF]

				R. A. Frost, G. J. Nystrom, and C. H. Lang Tumor Necrosis Factor-{alpha} Decreases Insulin-Like Growth Factor-I Messenger Ribonucleic Acid Expression in C2C12 Myoblasts via a Jun N-Terminal Kinase Pathway Endocrinology, May 1, 2003; 144(5): 1770 - 1779. [Abstract] [Full Text] [PDF]

				L. A. Denson, M. A. Held, R. K. Menon, S. J. Frank, A. F. Parlow, and D. L. Arnold Interleukin-6 inhibits hepatic growth hormone signaling via upregulation of Cis and Socs-3 Am J Physiol Gastrointest Liver Physiol, April 1, 2003; 284(4): G646 - G654. [Abstract] [Full Text] [PDF]

				G. Liu, L. Robillard, B. Banihashemi, and P. R. Albert Growth Hormone-induced Diacylglycerol and Ceramide Formation via Galpha i3 and Gbeta gamma in GH4 Pituitary Cells. POTENTIATION BY DOPAMINE-D2 RECEPTOR ACTIVATION J. Biol. Chem., December 6, 2002; 277(50): 48427 - 48433. [Abstract] [Full Text] [PDF]

				S.-O. Kim, K. Loesch, X. Wang, J. Jiang, L. Mei, J. M. Cunnick, J. Wu, and S. J. Frank A Role for Grb2-Associated Binder-1 in Growth Hormone Signaling Endocrinology, December 1, 2002; 143(12): 4856 - 4867. [Abstract] [Full Text] [PDF]

				G. Yumet, M. L. Shumate, P. Bryant, C.-M. Lin, C. H. Lang, and R. N. Cooney Tumor necrosis factor mediates hepatic growth hormone resistance during sepsis Am J Physiol Endocrinol Metab, September 1, 2002; 283(3): E472 - E481. [Abstract] [Full Text] [PDF]

				V. Beauloye, B. Willems, V. de Coninck, S. J. Frank, M. Edery, and J.-P. Thissen Impairment of Liver GH Receptor Signaling by Fasting Endocrinology, March 1, 2002; 143(3): 792 - 800. [Abstract] [Full Text] [PDF]

				M. S. Chacko and M. L. Adamo Double-Stranded RNA Decreases IGF-I Gene Expression in a Protein Kinase R-Dependent, but Type I Interferon-Independent, Mechanism in C6 Rat Glioma Cells Endocrinology, February 1, 2002; 143(2): 525 - 534. [Abstract] [Full Text] [PDF]

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Davey, H. W. Articles by Grattan, D. R. Search for Related Content PubMed PubMed Citation Articles by Davey, H. W. Articles by Grattan, D. R.