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Cigarette smoke-induced expression of heme oxygenase-1 in human lung fibroblasts is regulated by intracellular glutathione
- Source :
- The American Journal of Physiology. Oct, 2008, Vol. 295 Issue 4, pL624, 13 p.
- Publication Year :
- 2008
-
Abstract
- Fibroblasts are key structural cells that can be damaged by cigarette smoke. Cigarette smoke contains many components capable of eliciting oxidative stress, which may induce heine oxygenase (HO)-1, a cytoprotective enzyme. There are no data on HO-1 expression in primary human lung fibroblasts after cigarette smoke extract (CSE) exposure. We hypothesized that human lung fibroblasts exposed to cigarette smoke would increase HO-I though changes in intracellular glutathione (GSH). Primary human lung fibroblasts were exposed to CSE, and changes in HO-1 expression and GSH levels were assessed. CSE induced a time- and dose-dependent increase in expression of HO-1, but not HO-2 or biliverdin reductase, in two different primary human lung fibroblast strains, a novel finding. This induction of HO-1 paralleled a decrease in intracellular GSH, and a sustained reduction in GSH resulted in a dramatic increase in HO-1. Treatment with the antioxidants N-acetyl-L-cysteine or GSH reduced the expression of HO-I induced by CSE. We also examined the signal transduction mechanism responsible for HO-1 induction. Nuclear factor erythroid-derived 2, like 2 (Nrf2) was not involved in HO-1 induction by CSE. Activator protein-1 (AP-1) is a redox-sensitive transcription factor shown in other systems to regulate HO-1 expression. CSE exposure resulted in nuclear accumulation of c-Fos and c-Jun, two key AP-1 components. Reduction of c-Fos and c-Jun nuclear translocation by SP-600125 attenuated the CSE-induced expression of HO-1. These data support the concept that changes in the cellular redox status brought on by cigarette smoke induce HO-1 in fibroblasts. This increase in HO-1 may help protect against cigarette smoke-induced inflammation and/or cell death. oxidative stress; activator protein-l; biliverdin reductase; chronic obstructive pulmonary disease; nuclear factor erythroid-derived 2, like 2
Details
- Language :
- English
- ISSN :
- 00029513
- Volume :
- 295
- Issue :
- 4
- Database :
- Gale General OneFile
- Journal :
- The American Journal of Physiology
- Publication Type :
- Academic Journal
- Accession number :
- edsgcl.187841305