| Literature DB >> 7688028 |
Y Vodovotz1, C Bogdan, J Paik, Q W Xie, C Nathan.
Abstract
Activated mouse peritoneal macrophages produce nitric oxide (NO) via a nitric oxide synthase that is inducible by interferon gamma (IFN-gamma): iNOS. We have studied the mechanisms by which transforming growth factor beta 1 (TGF-beta) suppresses IFN-gamma-stimulated NO production. TGF-beta treatment reduced iNOS specific activity and iNOS protein in both cytosolic and particulate fractions as assessed by Western blot with monospecific anti-iNOS immunoglobulin G. TGF-beta reduced iNOS mRNA without affecting the transcription of iNOS by decreasing iNOS mRNA stability. Even after iNOS was already expressed, TGF-beta reduced the amount of iNOS protein. This was due to reduction of iNOS mRNA translation and increased degradation of iNOS protein. The potency of TGF-beta as a deactivator of NO production (50% inhibitory concentration, 5.6 +/- 2 pM) may reflect its ability to suppress iNOS expression by three distinct mechanisms: decreased stability and translation of iNOS mRNA, and increased degradation of iNOS protein. This is the first evidence that iNOS is subject to other than transcriptional regulation.Entities:
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Year: 1993 PMID： 7688028 PMCID： PMC2191129 DOI： 10.1084/jem.178.2.605
Source DB: PubMed Journal: J Exp Med ISSN： 0022-1007 Impact factor: 14.307