First Author | Xiao YQ | Year | 2006 |
Journal | J Immunol | Volume | 176 |
Issue | 2 | Pages | 1209-17 |
PubMed ID | 16394011 | Mgi Jnum | J:126440 |
Mgi Id | MGI:3761250 | Doi | 10.4049/jimmunol.176.2.1209 |
Citation | Xiao YQ, et al. (2006) Oxidants selectively reverse TGF-beta suppression of proinflammatory mediator production. J Immunol 176(2):1209-17 |
abstractText | Although TGF-beta inhibits the production of proinflammatory mediators in vitro and in vivo, its anti-inflammatory activities may be ineffective in early or severe acute inflammatory circumstances. In this study, we suggest a role for oxidative stress on TGF-beta signaling, leading to prevention of its normal anti-inflammatory effects but leaving its Smad-driven effects on cellular differentiation or matrix production unaffected. Stimulation of the RAW 264.7 macrophage cells, human or mouse alveolar macrophages with LPS led to NF-kappaB-driven production of proinflammatory mediators, which were inhibited by TGF-beta. This inhibition was prevented in the presence of hydrogen peroxide. We found that hydrogen peroxide acted by inducing p38 MAPK activation, which then prevented the ERK activation and MAPK phosphatase-1 up-regulation normally induced by TGF-beta. This was mediated through Src tyrosine kinases and protein phosphatase-1/2A. By contrast, hydrogen peroxide had no effects on TGF-beta-induced Smad2 phosphorylation and SBE-luc reporter gene transcription. |