Document Detail


Functional interaction of bone morphogenetic protein and growth hormone releasing peptide in adrenocorticotropin regulation by corticotrope cells.
MedLine Citation:
PMID:  21742013     Owner:  NLM     Status:  Publisher    
Abstract/OtherAbstract:
Mechanisms by which GHRP stimulates ACTH release in corticotrope cells were investigated using mouse corticotrope AtT20 cells by focusing on the biological activity of BMP-4. GHRP-2 increased ACTH and cAMP secretion by AtT20 cells; however, its effects were less potent than the effects of CRH. BMP-4 suppressed basal ACTH production and POMC transcription, and the inhibition of endogenous BMP receptor signaling led to an increase in ACTH production. Of note, BMP-4 suppressed ACTH production and POMC-promoter activity induced by CRH more efficaciously than that induced by GHRP-2. BMP-4 had no significant effect on cAMP synthesis induced by CRH or GHRP-2. Stimulation with CRH, but not GHRP-2, activated ERK1/2, p38, SAPK/JNK and Akt phosphorylation, in which CRH-induced phosphorylation of ERK and p38 was suppressed by BMP-4. GHRP-2-induced ACTH secretion was not affected by inhibitors of ERK, p38 and Akt pathways, which effectively suppressed CRH-induced ACTH release. Blockage of the cAMP-PKA pathway reversed CRH- as well as GHRP-2-induced ACTH secretion. Furthermore, the inhibition of ERK and p38 significantly reduced cAMP synthesis induced by CRH but not by GHRP-2. Thus, CRH activates ACTH production through ERK and p38 pathways in addition to the cAMP-PKA pathway, which is also activated downstream of MAPK. On the other hand, GHRP-2-induced ACTH production was predominantly linked to the cAMP-PKA pathway. Moreover, CRH and GHRP-2 upregulated BMP receptor signaling, while BMP-4, CRH and GHRP-2 had no significant effect on the expression level of GHSR. In addition, GHRP-2 suppressed the expression of Smad7, which is an inhibitor of the BMP-Smad1/5/8 pathway. Collectively, the results revealed a functional interaction between GHRP-2 and BMP signaling, in which endogenous BMP may act as an autoregulatory system in controlling ACTH production.
Authors:
Naoko Tsukamoto; Fumio Otsuka; Tomoko Miyoshi; Kenichi Inagaki; Eri Nakamura; Tomohiro Terasaka; Masaya Takeda; Toshio Ogura; Yasumasa Iwasaki; Hirofumi Makino
Related Documents :
3679753 - Phorbol ester: effect on intraocular pressure, adenylate cyclase, and protein kinase in...
2129393 - Effect of bacterial toxins on spermine-induced inhibition of adenylate cyclase activity...
19709933 - Pikk-dependent phosphorylation of mre11 induces mrn complex inactivation by disassembly...
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2011-7-1
Journal Detail:
Title:  Molecular and cellular endocrinology     Volume:  -     ISSN:  1872-8057     ISO Abbreviation:  -     Publication Date:  2011 Jul 
Date Detail:
Created Date:  2011-7-11     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  7500844     Medline TA:  Mol Cell Endocrinol     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Copyright Information:
Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.
Affiliation:
Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Separate and combined effects of low dose ketamine and nicotine on behavioural and neural correlates...
Next Document:  HSP90 interacting with IRS-2 is involved in cAMP-dependent potentiation of IGF-I signals in FRTL-5 c...