IGF-I regulates pro-opiomelanocortin and GH gene expression in the mouse pituitary gland

J. Honda, Y. Manabe, R. Matsumura, Sakae Takeuchi, S. Takahashi

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

IGF-I is expressed in somatotrophs, and IGF-I receptors are expressed in most somatotrophs and some corticotrophs in the mouse pituitary gland. Our recent study demonstrated that IGF-I stimulates the proliferation of corticotrophs in the mouse pituitary. These results suggested that somatotrophs regulate corticotrophic functions as well as somatotrophic functions by the mediation of IGF-I molecules. The present study aimed to clarify factors regulating pituitary IGF-I expression and also the roles exerted by IGF-I within the mouse anterior pituitary gland. Mouse anterior pituitary cells were isolated and cultured under serum-free conditions. GH (0-5 or 1 μg/ml), ACTH (10-8 or 10-7 M), GH-releasing hormone (GHRH; 10-8 or 10-7 M), dexamethasone (DEX; 10-8 or 10-7 M) and estradiol-17β (E2; 10-11 or 10-9 M) were given for 24h. IGF-I mRNA levels were measured using competitive RT-PCR, and GH and pro-opiomelanocortin (POMC) mRNA levels were measured using Northern blotting analysis. GH treatment significantly increased IGF-I mRNA levels (1.5- or 2.1-fold). ACTH treatment did not alter GH and IGF-I mRNA levels. IGF-I treatment decreased GH mRNA levels (0.7-or 0.5-fold), but increased POMC mRNA levels (1.8-fold). GH treatment (4 or 8 μg/ml) for 4 days increased POMC mRNA levels. GHRH treatment increased GH mRNA levels (1.3-fold), but not IGF-I mRNA levels. DEX treatment significantly decreased IGF-I mRNA levels (0.8-fold). E2 treatment did not affect IGF-I mRNA levels. GH receptor mRNA, probably with GH-binding protein mRNA, was detected in somatotrophs, and some mammotrophs and gonadotrophs by in situ hybridization using GH receptor cDNA as a probe. These results suggested that IGF-I expression in somatotrophs is regulated by pituitary GH, and that IGF-I suppresses GH expression and stimulates POMC expression at the transcription level. Pituitary IGF-I produced in somatotrophs is probably involved in the regulation of somatotroph and corticotroph functions.

Original languageEnglish
Pages (from-to)71-82
Number of pages12
JournalJournal of Endocrinology
Volume178
Issue number1
DOIs
Publication statusPublished - Jul 1 2003

Fingerprint

Pro-Opiomelanocortin
Pituitary Gland
Insulin-Like Growth Factor I
Gene Expression
Somatotrophs
Messenger RNA
Corticotrophs
Adrenocorticotropic Hormone
Gonadotrophs
IGF Type 1 Receptor
Anterior Pituitary Gland
Northern Blotting

ASJC Scopus subject areas

  • Endocrinology

Cite this

IGF-I regulates pro-opiomelanocortin and GH gene expression in the mouse pituitary gland. / Honda, J.; Manabe, Y.; Matsumura, R.; Takeuchi, Sakae; Takahashi, S.

In: Journal of Endocrinology, Vol. 178, No. 1, 01.07.2003, p. 71-82.

Research output: Contribution to journalArticle

@article{9908b806527a4f22aad38e6f9a173bca,
title = "IGF-I regulates pro-opiomelanocortin and GH gene expression in the mouse pituitary gland",
abstract = "IGF-I is expressed in somatotrophs, and IGF-I receptors are expressed in most somatotrophs and some corticotrophs in the mouse pituitary gland. Our recent study demonstrated that IGF-I stimulates the proliferation of corticotrophs in the mouse pituitary. These results suggested that somatotrophs regulate corticotrophic functions as well as somatotrophic functions by the mediation of IGF-I molecules. The present study aimed to clarify factors regulating pituitary IGF-I expression and also the roles exerted by IGF-I within the mouse anterior pituitary gland. Mouse anterior pituitary cells were isolated and cultured under serum-free conditions. GH (0-5 or 1 μg/ml), ACTH (10-8 or 10-7 M), GH-releasing hormone (GHRH; 10-8 or 10-7 M), dexamethasone (DEX; 10-8 or 10-7 M) and estradiol-17β (E2; 10-11 or 10-9 M) were given for 24h. IGF-I mRNA levels were measured using competitive RT-PCR, and GH and pro-opiomelanocortin (POMC) mRNA levels were measured using Northern blotting analysis. GH treatment significantly increased IGF-I mRNA levels (1.5- or 2.1-fold). ACTH treatment did not alter GH and IGF-I mRNA levels. IGF-I treatment decreased GH mRNA levels (0.7-or 0.5-fold), but increased POMC mRNA levels (1.8-fold). GH treatment (4 or 8 μg/ml) for 4 days increased POMC mRNA levels. GHRH treatment increased GH mRNA levels (1.3-fold), but not IGF-I mRNA levels. DEX treatment significantly decreased IGF-I mRNA levels (0.8-fold). E2 treatment did not affect IGF-I mRNA levels. GH receptor mRNA, probably with GH-binding protein mRNA, was detected in somatotrophs, and some mammotrophs and gonadotrophs by in situ hybridization using GH receptor cDNA as a probe. These results suggested that IGF-I expression in somatotrophs is regulated by pituitary GH, and that IGF-I suppresses GH expression and stimulates POMC expression at the transcription level. Pituitary IGF-I produced in somatotrophs is probably involved in the regulation of somatotroph and corticotroph functions.",
author = "J. Honda and Y. Manabe and R. Matsumura and Sakae Takeuchi and S. Takahashi",
year = "2003",
month = "7",
day = "1",
doi = "10.1677/joe.0.1780071",
language = "English",
volume = "178",
pages = "71--82",
journal = "Journal of Endocrinology",
issn = "0022-0795",
publisher = "Society for Endocrinology",
number = "1",

}

TY - JOUR

T1 - IGF-I regulates pro-opiomelanocortin and GH gene expression in the mouse pituitary gland

AU - Honda, J.

AU - Manabe, Y.

AU - Matsumura, R.

AU - Takeuchi, Sakae

AU - Takahashi, S.

PY - 2003/7/1

Y1 - 2003/7/1

N2 - IGF-I is expressed in somatotrophs, and IGF-I receptors are expressed in most somatotrophs and some corticotrophs in the mouse pituitary gland. Our recent study demonstrated that IGF-I stimulates the proliferation of corticotrophs in the mouse pituitary. These results suggested that somatotrophs regulate corticotrophic functions as well as somatotrophic functions by the mediation of IGF-I molecules. The present study aimed to clarify factors regulating pituitary IGF-I expression and also the roles exerted by IGF-I within the mouse anterior pituitary gland. Mouse anterior pituitary cells were isolated and cultured under serum-free conditions. GH (0-5 or 1 μg/ml), ACTH (10-8 or 10-7 M), GH-releasing hormone (GHRH; 10-8 or 10-7 M), dexamethasone (DEX; 10-8 or 10-7 M) and estradiol-17β (E2; 10-11 or 10-9 M) were given for 24h. IGF-I mRNA levels were measured using competitive RT-PCR, and GH and pro-opiomelanocortin (POMC) mRNA levels were measured using Northern blotting analysis. GH treatment significantly increased IGF-I mRNA levels (1.5- or 2.1-fold). ACTH treatment did not alter GH and IGF-I mRNA levels. IGF-I treatment decreased GH mRNA levels (0.7-or 0.5-fold), but increased POMC mRNA levels (1.8-fold). GH treatment (4 or 8 μg/ml) for 4 days increased POMC mRNA levels. GHRH treatment increased GH mRNA levels (1.3-fold), but not IGF-I mRNA levels. DEX treatment significantly decreased IGF-I mRNA levels (0.8-fold). E2 treatment did not affect IGF-I mRNA levels. GH receptor mRNA, probably with GH-binding protein mRNA, was detected in somatotrophs, and some mammotrophs and gonadotrophs by in situ hybridization using GH receptor cDNA as a probe. These results suggested that IGF-I expression in somatotrophs is regulated by pituitary GH, and that IGF-I suppresses GH expression and stimulates POMC expression at the transcription level. Pituitary IGF-I produced in somatotrophs is probably involved in the regulation of somatotroph and corticotroph functions.

AB - IGF-I is expressed in somatotrophs, and IGF-I receptors are expressed in most somatotrophs and some corticotrophs in the mouse pituitary gland. Our recent study demonstrated that IGF-I stimulates the proliferation of corticotrophs in the mouse pituitary. These results suggested that somatotrophs regulate corticotrophic functions as well as somatotrophic functions by the mediation of IGF-I molecules. The present study aimed to clarify factors regulating pituitary IGF-I expression and also the roles exerted by IGF-I within the mouse anterior pituitary gland. Mouse anterior pituitary cells were isolated and cultured under serum-free conditions. GH (0-5 or 1 μg/ml), ACTH (10-8 or 10-7 M), GH-releasing hormone (GHRH; 10-8 or 10-7 M), dexamethasone (DEX; 10-8 or 10-7 M) and estradiol-17β (E2; 10-11 or 10-9 M) were given for 24h. IGF-I mRNA levels were measured using competitive RT-PCR, and GH and pro-opiomelanocortin (POMC) mRNA levels were measured using Northern blotting analysis. GH treatment significantly increased IGF-I mRNA levels (1.5- or 2.1-fold). ACTH treatment did not alter GH and IGF-I mRNA levels. IGF-I treatment decreased GH mRNA levels (0.7-or 0.5-fold), but increased POMC mRNA levels (1.8-fold). GH treatment (4 or 8 μg/ml) for 4 days increased POMC mRNA levels. GHRH treatment increased GH mRNA levels (1.3-fold), but not IGF-I mRNA levels. DEX treatment significantly decreased IGF-I mRNA levels (0.8-fold). E2 treatment did not affect IGF-I mRNA levels. GH receptor mRNA, probably with GH-binding protein mRNA, was detected in somatotrophs, and some mammotrophs and gonadotrophs by in situ hybridization using GH receptor cDNA as a probe. These results suggested that IGF-I expression in somatotrophs is regulated by pituitary GH, and that IGF-I suppresses GH expression and stimulates POMC expression at the transcription level. Pituitary IGF-I produced in somatotrophs is probably involved in the regulation of somatotroph and corticotroph functions.

UR - http://www.scopus.com/inward/record.url?scp=0043172274&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0043172274&partnerID=8YFLogxK

U2 - 10.1677/joe.0.1780071

DO - 10.1677/joe.0.1780071

M3 - Article

C2 - 12844338

AN - SCOPUS:0043172274

VL - 178

SP - 71

EP - 82

JO - Journal of Endocrinology

JF - Journal of Endocrinology

SN - 0022-0795

IS - 1

ER -