Abnormal expression of telomerase/apoptosis limits type II alveolar epithelial cell replication in the early remodeling of usual interstitial pneumonia/idiopathic pulmonary fibrosis.
Hum Pathol
; 41(3): 385-91, 2010 Mar.
Article
em En
| MEDLINE
| ID: mdl-19954818
Idiopathic pulmonary fibrosis is a distinctive, usually fatal, type of chronic fibrosing interstitial pneumonia of unknown cause that increases in prevalence with advanced age, characterized by failure of alveolar re-epithelization and progressive scar formation. Recently, limitation of the replicative capacity of tissues determined by telomerase/apoptosis balance has been implicated in pathogenesis of age-related diseases. In this study, we validated the importance of the expression of type 2 alveolar epithelial cells telomerase protein and studied the relationships between telomerase and apoptosis in early remodeling of usual interstitial pneumonia. We determined type 2 alveolar epithelial cells density, telomerase expression, and apoptosis in surgical lung biopsies from 24 patients with usual interstitial pneumonia, and in normal lung tissues from 18 subjects. We used immunohistochemistry, deoxynucleotidyl transferase method of end labeling, electron microscopy, and histomorphometry to evaluate the amount of type 2 alveolar epithelial cells staining for surfactant-A, telomerase, and in situ detection of apoptotic cells. Unaffected areas of usual interstitial pneumonia and normal lung tissue had similar densities of type 2 alveolar epithelial cells, but a significant minor subpopulation of type 2 alveolar epithelial cells was telomerase positive and a large population was telomerase negative. A significant inverse association was found between low type 2 alveolar epithelial cell telomerase expression and high apoptosis in unaffected areas of usual interstitial pneumonia. Although type 2 alveolar epithelial cell telomerase expression was higher than apoptosis in NLT group, no significant association was found between them. Electron microscopy confirmed epithelial apoptosis, alveolar collapse, and initial fibroplasia. We conclude that abnormal type 2 alveolar epithelial cells telomerase/apoptosis balance may reduce alveolar epithelial regenerative capacity, thus contributing to the early remodeling response in usual interstitial pneumonia.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Apoptose
/
Telomerase
/
Proliferação de Células
/
Fibrose Pulmonar Idiopática
/
Células Epiteliais Alveolares
Tipo de estudo:
Prognostic_studies
/
Risk_factors_studies
Limite:
Aged
/
Female
/
Humans
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Male
/
Middle aged
Idioma:
En
Revista:
Hum Pathol
Assunto da revista:
PATOLOGIA
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Estados Unidos