Regulation of insulin-like growth factor I gene expression by growth hormone.

Mathews, Lawrence S.; Norstedt, Gunnar; Palmiter, Richard D.

doi:10.1073/pnas.83.24.9343

Cited by 525 publications

(269 citation statements)

References 39 publications

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“…Within the liver, the biosynthesis of The adult liver has been recognized as the major site individual proteins has been attributed to different of IGF biosynthesis. 4,5 cell populations, e.g., that of ALS to hepatocytes and…”

Section: The Adult Liver Is the Main Source Of Circulatingmentioning

confidence: 99%

Synthesis of insulinlike growth factor binding proteins and of the acid-labile subunit in primary cultures of rat hepatocytes, of Kupffer cells, and in cocultures: Regulation by insulin, insulinlike growth factor, and growth hormone

Scharf¹,

Ramadori²,

Braulke³

et al. 1996

Hepatology

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The adult liver is the main source of circulatingThe insulinlike growth factors (IGF-I and IGF-II) are insulinlike growth factors (IGFs ) and their serum circulating peptides with structural homology to proinbinding proteins (IGFBPs) including the acid-labile sulin. 1,2 They are known to participate in the regulation subunit (ALS), a component of the ternary binding of growth, metabolism, and cellular differentiation. 3 protein complex. Within the liver, the biosynthesis of The adult liver has been recognized as the major site individual proteins has been attributed to different of IGF biosynthesis. 4,5 cell populations, e.g., that of ALS to hepatocytes andIn serum, IGFs bind with high affinity to specific that of IGFBP-3 to nonparenchymal cells. Ligand and binding proteins. So far, six distinct binding proteins immunoblotting as well as Northern blotting analyses (named IGFBP-1 to -6) have been identified. 6 In the 3, and of the acid-labile subunit (ALS). 7,8 Formation ofsynthesis of IGFBP-1, -2, and -4 was observed; insulin and IGF-I decreased that of IGFBP-1, and -2 while in-this ternary complex is believed to prolong half-life of creasing that of IGFBP-4. KCs synthesized IGFBP-2, IGFs in systemic circulation 9 and to prevent acute insuand -3, insulin and IGF-I showing no effect. In cocul-linlike actions of these peptides, i.e., hypoglycemia. In tures, however, synthesis of IGFBP-3 was stimulated addition, IGFs form binary complexes with other by insulin and IGF-I. By immunocytochemistry IGFBPs (e.g., IGFBP-1, -2, and -4) of 31 to 40 kd that IGFBP-3 biosynthesis was localized to KCs exclu-are capable of crossing capillary walls and facilitating sively. When pore membranes were used for separa-IGF transport to target tissues. 10 tion of hepatocytes and KCs in coculture, this in-The biosynthesis of serum IGFBPs has been localized sulin-stimulatory action on IGFBP-3 synthesis was to the liver, too. 11 Recently, several studies in rats have size this glycosylated 82-to 88-kd protein. 16,17 Regulation of biosynthesis of individual IGFBPs and of ALS is not uniform and apparently linked to condi- Before the addition of hormones, cultures and cocultures of rat liver cells specific activity of approximately 60 to 80 mCi/mg. Porcine insulin, dexamethasone, and glucose oxidase were obtained were washed with the M-199 medium supplemented with 0.2% (wt/vol) BSA and then incubated in the culture medium from Sigma Chemical Co. (Deisenhofen, Germany). Human GH was kindly donated by Nordisk (Mainz, Germany). En-at 37ЊC for 1 hour. The medium was then replaced by fresh medium supplemented with 0.2% (wt/vol) BSA, and the cells zymes, fetal calf serum (FCS), and M-199 medium were purchased from Boehringer Mannheim (Mannheim, Germany). were incubated in the presence or absence of insulin, IGF-I, and GH in concentrations ranging from 0.1 to 100 nmol/L Bovine serum albumin (BSA), glucagon, and antibiotics were from Serva Feinbiochemica Gmbtt & Co. KG (Heidelberg, each for 36 hours.Immunocytochemistry. For immunocytochemical analys...

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Section: The Adult Liver Is the Main Source Of Circulatingmentioning

confidence: 99%

Synthesis of insulinlike growth factor binding proteins and of the acid-labile subunit in primary cultures of rat hepatocytes, of Kupffer cells, and in cocultures: Regulation by insulin, insulinlike growth factor, and growth hormone

Scharf¹,

Ramadori²,

Braulke³

et al. 1996

Hepatology

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“…Restriction of the vector (pCRII) containing a fragment of the oPR cDNA with HindIII allows the synthesis of an anti-sense RNA probe using T7 RNA polymerase. The 35 S-UTP-labeled cRNA was hybridized (20 000-40 000 cpm per incubation) at 70 °C to TNA samples as described by Mathews et al [19]. Incubation was performed in duplicates at two different concentrations, in microcentrifuge tubes (Treff AG, Switzerland) in a volume of 40 µl containing 0.6 M NaCl, 20 mM Tris-HCl (pH 7.5), 4 mM EDTA, 0.1% SDS, 0.75 mM DTT, and 25% formamide under two drops of paraffin oil.…”

Section: Hybridization Analysis Of Mrnamentioning

confidence: 99%

A biphasic action of estradiol on estrogen and progesterone receptor expression in the lamb uterus

et al. 2000

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-Regulation of the uterine expression of estrogen and progesterone receptors was studied in 20 three-month-old lambs that were not treated or treated with estradiol-17β. Determinations of receptors were performed by binding assays in the nuclear and cytosolic fractions, receptor mRNAs by solution hybridization, and estrogen receptor protein by an enzyme-immunoassay. Estradiol treatment decreased the receptor binding capacity of both receptors and the levels of immunoreactive estrogen receptor 12 h after injection in the absence of decreased receptor mRNAs, suggesting that the initial decrease is due to degradation of the proteins or that mRNAs are translated into new receptor proteins at a reduced rate. The mRNA levels increased after estradiol treatment suggesting that the replenishment phase consists of synthesis of new receptors rather than recycling of inactivated receptors.estrogen / progesterone / receptor / uterus / lamb Résumé -Action biphasique de l'oestradiol sur l'expression des récepteurs aux oestrogènes et à la progestérone dans l'utérus de l'agnelle. La régulation de l'expression des récepteurs aux oestrogènes et à la progestérone au niveau de l'utérus a été étudiée chez des agnelles immatures âgées de 3 mois (n = 20), traitées et non traitées avec oestradiol-17β. Les déterminations des récepteurs ont été faites par des essais de liaison dans les fractions nucléaires et cytosoliques, les ARNm des récepteurs par la méthode d'hybridation en solution et la protéine du récepteur aux oestrogènes par un essai immuno-enzymatique. Le traitement à l'oestradiol réduit la capacité de liaison des deux récepteurs et les niveaux des récepteurs aux oestrogènes immunoréactifs 12 h après l'injection en absence d'une diminution des ARNm des récepteurs, suggèrent que la réduction initiale est due à la dégradation des Reprod. Nutr. Dev. 40 (2000) 283-293 283

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“…Key Words • rats • cardiac volume • insulin-like growth factor I • growth hormone • fistula • wall stress content is growth hormone (GH), and GH enhances IGF-I transcription 9 as well as the abundance of IGF-I mRNA in most rodent tissues. 910 The effects of GH are evoked by the interaction of the ligand with its cellular receptor, and recent studies suggest that the tissue response is also dependent on the expression of the GH receptor.…”

Section: ;23[part 2]: 884-888)mentioning

confidence: 99%

Increased expression of growth hormone receptor mRNA and insulin-like growth factor-I mRNA in volume-overloaded hearts.

et al. 1994

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Recent results suggest that insulin-like growth factor-I (IGF-I) may be involved in the transition of a hemodynamic load into cardiac hypertrophy and that the expression of IGF-I seems to be coupled to increased wall stress. The present study investigated the role of growth hormone (GH) and IGF-I in myocardial hypertrophy induced by volume overload. An aortocaval fistula (ACF) was created in male Wistar rats, and experiments were performed 2, 4, and 7 days after the onset of volume overload. Right and left ventricular (RV and LV, respectively) myocardial expression of GH receptor mRNA and IGF-I mRNA were quantitated by a solution hybridization RNase protection assay. RV GH receptor mRNA content was elevated on the fourth and seventh days after the induction of the shunt, with peak levels (0.63±0.16 versus 0.14±0.03 amol//ig DNA for the shamoperated animals; P<.01) after 4 days. Similarly, IGF-I mRNA was significantly increased in the RV of shunted animals T he heart responds to an increased systemic pressure load with an adaptive hypertrophy of the left ventricle.1 -2 Moreover, volume overload (ie, increased venous return resulting in increased cardiac output) induces cardiac hypertrophy characterized by a proportional increase in internal chamber volume and wall thickness. -3 However, the mechanisms involved in the conversion of the mechanical stimuli into an increased tissue mass are less known, although several factors, including proto-oncogenes and growth factors, have been proposed to be involved in this process. -5The presence of insulin-like growth factor-I (IGF-I) mRNA in the rat heart has been shown, 6 and it was recently demonstrated that IGF-I mRNA and protein were induced specifically in the pressure-overloaded left ventricle of two-kidney, one clip rats.7 Presumably, IGF-I gene expression was coupled to the increased left ventricular (LV) workload, and IGF-I thus constitutes a possible mediator of cardiac hypertrophy in response to hemodynamic load. This adds further support to the fact that IGF-I is synthesized in peripheral tissues and exerts paracrine-autocrine effects during tissue growth 8 and that it can be produced in specific regions within the heart. The primary regulator of local IGF-I mRNA (1.26±0.13 versus 0.56±0.05 amol/^g DNA; F<.01) 7 days after surgery. In the left ventricle, where systolic pressure was reduced in ACF rats, no differences could be detected in GH receptor and IGF-I mRNA content between ACF and shamoperated rats on any of the experimental days. There was no difference in the ratio of RV to LV weight during the experimental period. We have shown that the thin-walled right ventricle responds to volume overload with an increase of GH receptor mRNA content followed by elevated expression of IGF-I mRNA. The present results suggest that the heart regionally produces trophically acting factors, such as IGF-I, which may be of importance for the initiation of the hypertrophic process, at least when a ventricle is being challenged, such as the right ventricle in volume ...

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Regulation of insulin-like growth factor I gene expression by growth hormone.

Cited by 525 publications

References 39 publications

Synthesis of insulinlike growth factor binding proteins and of the acid-labile subunit in primary cultures of rat hepatocytes, of Kupffer cells, and in cocultures: Regulation by insulin, insulinlike growth factor, and growth hormone

Synthesis of insulinlike growth factor binding proteins and of the acid-labile subunit in primary cultures of rat hepatocytes, of Kupffer cells, and in cocultures: Regulation by insulin, insulinlike growth factor, and growth hormone

A biphasic action of estradiol on estrogen and progesterone receptor expression in the lamb uterus

Increased expression of growth hormone receptor mRNA and insulin-like growth factor-I mRNA in volume-overloaded hearts.

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