Aging impairs alveolar epithelial type II cell function in acute lung injury.
Am J Physiol Lung Cell Mol Physiol
; 319(5): L755-L769, 2020 11 01.
Article
em En
| MEDLINE
| ID: mdl-32877222
ABSTRACT
Morbidity and mortality rates in acute lung injury (ALI) increase with age. As alveolar epithelial type II cells (AE2) are crucial for lung function and repair, we hypothesized that aging promotes senescence in AE2 and contributes to the severity and impaired regeneration in ALI. ALI was induced with 2.5 µg lipopolysaccharide/g body weight in young (3 mo) and old (18 mo) mice that were euthanized 24 h, 72 h, and 10 days later. Lung function, pulmonary surfactant activity, stereology, cell senescence, and single-cell RNA sequencing analyses were performed to investigate AE2 function in aging and ALI. In old mice, surfactant activity was severely impaired. A 60% mortality rate and lung function decline were observed in old, but not in young, mice with ALI. AE2 of young mice adapted to injury by increasing intracellular surfactant volume and proliferation rate. In old mice, however, this adaptive response was compromised, and AE2 of old mice showed signs of cell senescence, increased inflammatory signaling, and impaired surfactant metabolism in ALI. These findings provide evidence that ALI promotes a limited proliferation rate, increased inflammatory response, and surfactant dysfunction in old, but not in young, mice, supporting an impaired regenerative capacity and reduced survival rate in ALI with advancing age.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Surfactantes Pulmonares
/
Envelhecimento
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Lesão Pulmonar Aguda
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Células Epiteliais Alveolares
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article