Maturational factors modulate transcription factors CCAAT/enhancer-binding proteins alpha, beta, delta, and peroxisome proliferator-activated receptor-gamma in fetal rat lung epithelial cells.
Am J Respir Cell Mol Biol
; 29(5): 620-6, 2003 Nov.
Article
in En
| MEDLINE
| ID: mdl-14568882
ABSTRACT
Previous investigations have evidenced the importance of CCAAT/enhancer-binding proteins (C/EBPs) and peroxisome proliferator-activated receptor (PPAR)gamma for lung development, especially for alveolar type II cells (ATII). This prompted us to explore whether ATII maturation-promoting mediators controlled their expression in isolated ATII. In whole rat lung, C/EBPalpha, beta, delta, and PPARgamma mRNAs increased 3-5 times between gestational day 18 and term (Day 22), dropped around birth, then reincreased. C/EBPbeta and delta, but not PPARgamma, displayed similar profile in isolated ATII; C/EBPalpha transcript disappeared and the protein became hardly detectable in isolated cells. In cultured ATII, dexamethasone increased C/EBPbeta and PPARgamma mRNAs 2-4 times, and cyclic AMP increased C/EBPbeta and delta mRNAs approximately 1.5 times. Whereas retinoic acid increased C/EBPbeta and PPARgamma mRNAs 1.5 times in ATII in vitro, vitamin-A deficiency strongly decreased fetal lung C/EBPalpha, beta, and PPARgamma transcripts in vivo. C/EBPbeta, delta, and PPARgamma mRNAs were also increased in vitro by epidermal growth factor and keratinocyte growth factor, whereas they were unchanged by the maturation inhibitor transforming growth factor-beta. C/EBPalpha expression was not reinduced by any mediator. Changes in transcripts were reflected in protein levels analyzed through Western blotting. These results argue for a role of these factors in ATII functional maturation, and indicate a multifactorial control of their ontogeny.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Transcription Factors
/
Receptors, Cytoplasmic and Nuclear
/
CCAAT-Enhancer-Binding Proteins
/
Lung
Limits:
Animals
Language:
En
Journal:
Am J Respir Cell Mol Biol
Journal subject:
BIOLOGIA MOLECULAR
Year:
2003
Document type:
Article
Affiliation country: