Alveolar epithelial cells regulate the induction of endothelial cell apoptosis.
Am J Physiol
; 267(4 Pt 1): C893-900, 1994 Oct.
Article
em En
| MEDLINE
| ID: mdl-7943282
ABSTRACT
Mesenchymal cell apoptosis is important during development, tissue homeostasis, and repair. We sought to determine whether type II alveolar epithelial cells influence mesenchymal cell apoptosis, using the model of tumor necrosis factor-alpha (TNF-alpha)-induced apoptosis of endothelial cells. Apoptosis was quantified by morphology and confirmed by electrophoretic DNA size analysis. Endothelial cells exposed to 20 ng/ml of TNF-alpha for 16 h exhibited apoptosis in 14.4 +/- 1.4% (SE) of the cells, whereas serum-free conditioned media (CM) from primary cultures of rat type II cells reduced TNF-alpha-induced apoptosis by 52% to 7.5 +/- 0.9% (P < 0.01). Flow cytometric analysis of subdiploid DNA content per cell also showed that CM reduced the percentage of cells with TNF-alpha-induced DNA degradation by 48 +/- 1.7%. The protective effect of CM was concentration dependent and also was effective across a range of TNF concentrations. This CM factor was trypsin sensitive and stable at 65 degrees C for 1 h. It bound to a Mono-Q anion-exchange resin, eluting in a discrete peak at 1.18 M NaCl and pH 8.5. Therefore alveolar type II cells release a heat-stable peptide(s) that protects endothelial cells against apoptosis induced by TNF. Our results suggest that alveolar epithelial cells regulate the response of mesenchymal cells to factors that induce apoptosis during injury and repair.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Alvéolos Pulmonares
/
Apoptose
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Am J Physiol
Ano de publicação:
1994
Tipo de documento:
Article