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Query: UMLS:C0034067 (
emphysema
)
11,506
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Transforming growth factor (TGF)-beta1 has been reported to cause endothelial cell apoptosis. However, conflicting data have also demonstrated that TGF-beta1 promotes endothelial cell survival. In this study, the effect of TGF-beta1 on apoptosis of cultured bovine pulmonary artery endothelial cells (PAEC) induced by multiple stimuli was investigated. TGF-beta1 protected against apoptosis of bovine PAEC induced by serum deprivation or the VEGF receptor inhibitor SU-5416, but not by UV light exposure or TNFalpha. Neither
caspase-8
nor caspase-12 was activated by serum deprivation or the VEGF receptor blocker. However, blockade of VEGF receptors activated caspase-9, an effect that was abolished by TGF-beta1. Furthermore, serum deprivation and inhibition of VEGF receptors significantly decreased the protein level of Bcl-2, an effect that was also abrogated by TGF-beta1. In addition, the baseline level of Bcl-2 was enhanced by TGF-beta1 and reduced by inhibition of activin receptor-like kinase 5 (ALK5), a TGF-beta1 type I receptor. Furthermore, inhibition of ALK5 caused apoptosis of bovine PAEC. These results suggest that TGF-beta1 signaling is critical for maintenance of bovine PAEC survival. Finally, the protective effects of TGF-beta1 on bovine PAEC apoptosis and Bcl-2 reduction were abolished by ALK5 inhibition, but not by inhibition of non-SMAD signaling pathways. Also, TGF-beta1 activated SMAD2 and SMAD1/5, an effect that was abolished by ALK5 inhibition. The results of this study suggest that TGF-beta1 protects against bovine PAEC apoptosis, possibly through ALK5-mediated Bcl-2 induction and subsequent inhibition of the mitochondria-mediated intrinsic pathway of apoptosis. Understanding the mechanism by which TGF-beta1 promotes endothelial cell survival may provide a better treatment for apoptosis-dependent vascular diseases, such as
emphysema
.
...
PMID:Transforming growth factor-beta1 protects against pulmonary artery endothelial cell apoptosis via ALK5. 1845 97
Cigarette smoke, a major causative agent of chronic obstructive pulmonary disease (COPD), induces lung cell death by incompletely understood mechanisms. The induction of apoptosis in lung structural cells by cigarette smoke may contribute to the pathogenesis of
emphysema
. Phosphodiesterase-4 (PDE4) inhibitors are anti-inflammatory agents used in COPD therapy that can prevent cigarette smoke-induced
emphysema
in mice. We investigated the effect of rolipram, a first generation PDE4 inhibitor, on the regulation of cigarette smoke-induced apoptosis. Human lung fibroblast (MRC-5) cells were exposed to cigarette smoke extract (CSE). Cell viability and apoptosis were determined by MTT assay and Annexin-V staining, respectively. Caspase activation was determined by Western immunoblot analysis. Rolipram protected against cell death and increased viability in MRC-5 fibroblasts after CSE exposure. Furthermore, rolipram protected against apoptosis, decreased caspase-3 and -8 cleavage in MRC-5 cells exposed to CSE. Pre-treatment with rolipram enhanced Akt phosphorylation and associated cytoprotection in CSE-treated cells, which could be reversed by the PI3K inhibitor LY294002 partly. In conclusion, rolipram protects against apoptosis of MRC-5 cells through inhibition of caspase-3 and
caspase-8
. Rolipram may represent an effective therapeutic agent to reduce cigarette smoke-induced apoptosis of lung fibroblasts.
...
PMID:The phosphodiesterase 4 inhibitor rolipram protects against cigarette smoke extract-induced apoptosis in human lung fibroblasts. 2349 92