Acid Sphingomyelinase Inhibition Attenuates Cell Death in Mechanically Ventilated Newborn Rat Lung.
Am J Respir Crit Care Med
; 199(6): 760-772, 2019 03 15.
Article
en En
| MEDLINE
| ID: mdl-30326731
RATIONALE: Premature infants subjected to mechanical ventilation (MV) are prone to lung injury that may result in bronchopulmonary dysplasia. MV causes epithelial cell death and halts alveolar development. The exact mechanism of MV-induced epithelial cell death is unknown. OBJECTIVES: To determine the contribution of autophagy to MV-induced epithelial cell death in newborn rat lungs. METHODS: Newborn rat lungs and fetal rat lung epithelial (FRLE) cells were exposed to MV and cyclic stretch, respectively, and were then analyzed by immunoblotting and mass spectrometry for autophagy, apoptosis, and bioactive sphingolipids. MEASUREMENTS AND MAIN RESULTS: Both MV and stretch first induce autophagy (ATG 5-12 [autophagy related 5-12] and LC3B-II [microtubule-associated proteins 1A/1B light chain 3B-II] formation) followed by extrinsic apoptosis (cleaved CASP8/3 [caspase-8/3] and PARP [poly(ADP-ribose) polymerase] formation). Stretch-induced apoptosis was attenuated by inhibiting autophagy. Coimmunoprecipitation revealed that stretch promoted an interaction between LC3B and the FAS (first apoptosis signal) cell death receptor in FRLE cells. Ceramide levels, in particular C16 ceramide, were rapidly elevated in response to ventilation and stretch, and C16 ceramide treatment of FRLE cells induced autophagy and apoptosis in a temporal pattern similar to that seen with MV and stretch. SMPD1 (sphingomyelin phosphodiesterase 1) was activated by ventilation and stretch, and its inhibition prevented ceramide production, LC3B-II formation, LC3B/first apoptosis signal interaction, caspase-3 activation, and, ultimately, FLRE cell death. SMPD1 inhibition also attenuated ventilation-induced autophagy and apoptosis in newborn rats. CONCLUSIONS: Ventilation-induced ceramides promote autophagy-mediated cell death, and identifies SMPD1 as a potential therapeutic target for the treatment of ventilation-induced lung injury in newborns.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Respiración Artificial
/
Esfingomielina Fosfodiesterasa
/
Recién Nacido
/
Muerte Celular
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Células Epiteliales
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Pulmón
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Am J Respir Crit Care Med
Asunto de la revista:
TERAPIA INTENSIVA
Año:
2019
Tipo del documento:
Article
País de afiliación:
Canadá
Pais de publicación:
Estados Unidos