The ex vivo differential expression of apoptosis signaling cofactors in the developing perinatal lung: Essential role of oxygenation during the transition from placental to pulmonary-based respiration
Jje. Haddad et al., The ex vivo differential expression of apoptosis signaling cofactors in the developing perinatal lung: Essential role of oxygenation during the transition from placental to pulmonary-based respiration, BIOC BIOP R, 281(2), 2001, pp. 311-316
Citations number
16
Categorie Soggetti
Biochemistry & Biophysics
Journal title
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
The signaling pathways implicated in regulating apoptosis in the perinatal
developing lung are not well characterized. We have previously shown that a
poptosis signaling cofactors in the fetal alveolar epithelium are redox-sen
sitive and differentially expressed in response to oxyexcitation (Haddad an
d Land, Biochem, Biophys, Res. Commun. 271, 257-267, 2000), In this report
we investigated the role of oxygenation during the transition period from p
lacental to pulmonary-based respiration in regulating the differential expr
ession of apoptosis cofactors ex vivo. The antiapoptotic proto-oncogene, Bc
l-2, exhibited suppressed abundance commencing after birth, an effect which
was partially restored at a later stage of development, Oxygenation-modiat
ed down-regulation of Bcl-2 was accompanied by suppression of Bax, such tha
t Bcl-2/Bax equilibrium ratio remained steadily constant postnatally, Analy
sis of whether a Bax-independent pathway is involved in cell death in the p
erinatal lung revealed a novel role for p53, whose abundance predominated t
hat of Bcl-2 and Bax at different stages of gestational development. We con
clude that apoptosis ex vivo is partly Bar-insensitive and mediated by supp
ression of Bcl-2 in a p53-dependent mechanism. (C) 2001 Academic Press.