Linked Life Data

1999156

Source:http://linkedlifedata.com/resource/pubmed/id/1999156

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1991-4-10
pubmed:abstractText
Chromogranin A (CgA) is a 50 kilodalton (kDa) acidic glycoprotein that is costored and cosecreted from secretory granules with endogenous hormone from diverse endocrine cell types. The physiological role(s) of CgA is yet to be defined. In this study we used the AtT-20 mouse corticotropic cell line, which produces both CgA and POMC-derived peptides, to study 1) the regulation of CgA and POMC synthesis and secretion, and 2) the influence of CgA on POMC secretion. To study regulation of CgA and POMC biosynthesis and secretion, cells were treated with dexamethasone (DEX) or CRF for 48 h and CgA and POMC messenger RNAs and proteins were analyzed. Exposure to DEX for 48 h (10 nM) inhibited secretion of the 16 K fragment of POMC by 60% while stimulating CgA secretion 500% of control value. Consonant with these changes in protein, POMC mRNA levels fell to 40% of control levels while CgA mRNA levels increased to 250% of control values with DEX treatment. DEX treatment had no effect on the sizes of the CgA [2.1 kilobase (kb)] and POMC (1.0 kb) mRNAs. CRF (100 nM) stimulated secretion of both CgA (4-fold) and ACTH (2.5-fold) above basal values. By contrast, CRF increased POMC mRNA levels but had no effect on levels of CgA mRNA. Changes in total peptide production paralleled the changes in mRNA levels. Because DEX differentially regulated CgA and POMC synthesis and secretion, we questioned whether CgA could function as an autocrine inhibitor of hormone secretion. CgA inhibited CRF-stimulated secretion of 16 K fragment in a concentration-dependent manner (100% at 100 nM) without affecting basal 16 K fragment secretion. Moreover, anti-CgA antiserum, but not nonimmune serum, increased basal 16 K fragment secretion 2-fold and CRF-stimulated 16 K fragment secretion 1.5-fold. These results suggest that CgA plays an autocrine role as a glucocorticoid responsive inhibitor of POMC-derived peptide secretion.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0013-7227
pubmed:author
pubmed:issnType
Print
pubmed:volume
128
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1345-51
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
A proposed role for chromogranin A as a glucocorticoid-responsive autocrine inhibitor of proopiomelanocortin secretion.
pubmed:affiliation
Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.