Synergy between A2B adenosine receptors and hypoxia in activating human lung fibroblasts.

Autor: Zhong H; Department of Drug Research and Pharmacological Sciences, CV Therapeutics, Inc., 3172 Porter Drive, Palo Alto, CA 94304, USA., Belardinelli L, Maa T, Zeng D
Jazyk: angličtina
Zdroj: American journal of respiratory cell and molecular biology [Am J Respir Cell Mol Biol] 2005 Jan; Vol. 32 (1), pp. 2-8. Date of Electronic Publication: 2004 Oct 07.
DOI: 10.1165/rcmb.2004-0103OC
Abstrakt: Chronic inflammatory airway diseases, such as asthma, chronic obstructive pulmonary disease and pulmonary fibrosis, are associated with subepithelial fibroblast activation, myofibroblast hyperplasia, hypoxia, and increase in interstitial adenosine concentrations. The goal of this study was to determine the effect of adenosine and its receptors on activation of human lung fibroblasts under normoxia (21% O2) and hypoxia (5% O2). Under the normoxic condition, adenosine and its stable analog, 5'-(N-ethylcarboxamido)-adenosine, via activation of A2B adenosine receptors, increased the release of interleukin (IL)-6 by 14-fold and induced the differentiation of human lung fibroblasts to myofibroblasts. This latter effect of 5'-(N-ethylcarboxamido)-adenosine was abolished by an IL-6-neutralizing antibody. Hypoxia increased the release of IL-6 by 2.8-fold, and there was a synergy between hypoxia and activation of A2B adenosine receptors to increase the release of IL-6 and to induce differentiation of fibroblasts into myofibroblasts. Hypoxia increased the expression of A2B adenosine receptors by 3.4-fold. Altogether, these data suggest that hypoxia amplifies the effect of adenosine on the release of IL-6 and cell differentiation by upregulating the expression of A2B adenosine receptors. Our findings provide a novel mechanism whereby adenosine participates in the remodeling process of inflammatory lung diseases.
Databáze: MEDLINE