Inhibition of Inducible Nitric Oxide Synthase Expression by Interferons α and β in Bovine Retinal Pigmented Epithelial Cells

Abstract

Bovine retinal pigmented epithelial (RPE) cells express an inducible nitric oxide synthase (NOS-2) after activation with interferon (IFN)-γ and lipopolysaccharide (LPS). Experiments were performed to investigate the effects of IFN-α and IFN-β on NOS-2 activity. These types of interferons did not aid LPS in the production of nitrite, but markedly inhibited in a concentration-dependent manner the nitrite release due to LPS/IFN-γ. Analysis by Western and Northern blots showed that RPE cells co-stimulated with IFN-α or IFN-β with LPS/IFN-γ accumulated lower levels of NOS-2 protein and mRNA than in the presence of LPS/IFN-γ alone. The presence of IFN-α or IFN-β did not accelerate mRNA degradation, implying that these interferons did not affect NOS-2 mRNA stability, but more probably NOS-2 gene expression. Furthermore, IFN-γ binding studies demonstrated that the inhibitory effect of IFN-α and IFN-β is not caused by a blocking of IFN-γ receptors. Analysis of NF-κB activation by electrophoretic mobility shift assay demonstrated that LPS/IFN-γ-induced NF-κB binding was not changed by the presence of IFN-α. However, similar experiments revealed that the activation of interferon regulatory factor-1 (IRF-1) by LPS/IFN-γ was decreased by IFN-α. This phenomenon could be due to the decline of IRF-1 mRNA and the up-regulation of IRF-2 mRNA, an IRF-1 repressor, by IFN-α. These results suggest that the inhibitory effect of IFN-α and -β on NOS-2 induction could be partially explained by their effect on the induction of the IRFs, which were involved in NOS-2 gene transcription. Bovine retinal pigmented epithelial (RPE) cells express an inducible nitric oxide synthase (NOS-2) after activation with interferon (IFN)-γ and lipopolysaccharide (LPS). Experiments were performed to investigate the effects of IFN-α and IFN-β on NOS-2 activity. These types of interferons did not aid LPS in the production of nitrite, but markedly inhibited in a concentration-dependent manner the nitrite release due to LPS/IFN-γ. Analysis by Western and Northern blots showed that RPE cells co-stimulated with IFN-α or IFN-β with LPS/IFN-γ accumulated lower levels of NOS-2 protein and mRNA than in the presence of LPS/IFN-γ alone. The presence of IFN-α or IFN-β did not accelerate mRNA degradation, implying that these interferons did not affect NOS-2 mRNA stability, but more probably NOS-2 gene expression. Furthermore, IFN-γ binding studies demonstrated that the inhibitory effect of IFN-α and IFN-β is not caused by a blocking of IFN-γ receptors. Analysis of NF-κB activation by electrophoretic mobility shift assay demonstrated that LPS/IFN-γ-induced NF-κB binding was not changed by the presence of IFN-α. However, similar experiments revealed that the activation of interferon regulatory factor-1 (IRF-1) by LPS/IFN-γ was decreased by IFN-α. This phenomenon could be due to the decline of IRF-1 mRNA and the up-regulation of IRF-2 mRNA, an IRF-1 repressor, by IFN-α. These results suggest that the inhibitory effect of IFN-α and -β on NOS-2 induction could be partially explained by their effect on the induction of the IRFs, which were involved in NOS-2 gene transcription. Nitric oxide (NO) 1The abbreviations used are: NO, nitric oxide; IRF, interferon regulatory factor; NOS, nitric oxide synthase; RPE, retinal pigmented epithelial; GAPDH, glyceraldehyde-3-phosphate dehydrogenase; NMMA,N G-monomethyl-l-arginine; LPS, lipopolysaccharide; IFN, interferon; PBS, phosphate-buffered saline; PCR, polymerase chain reaction; RT, reverse transcriptase; EMSA, electrophoretic mobility shift assay; h, human; b, bovine. 1The abbreviations used are: NO, nitric oxide; IRF, interferon regulatory factor; NOS, nitric oxide synthase; RPE, retinal pigmented epithelial; GAPDH, glyceraldehyde-3-phosphate dehydrogenase; NMMA,N G-monomethyl-l-arginine; LPS, lipopolysaccharide; IFN, interferon; PBS, phosphate-buffered saline; PCR, polymerase chain reaction; RT, reverse transcriptase; EMSA, electrophoretic mobility shift assay; h, human; b, bovine. is an important signaling molecule that mediates a variety of essential physiological processes including neurotransmission, vasodilatation, and host cell defense (1Knowles R.G. Moncada S. Biochem. J. 1994; 298: 249-258Crossref PubMed Scopus (2487) Google Scholar, 2Nathan C. Xie Q. Cell. 1994; 78: 915-918Abstract Full Text PDF PubMed Scopus (2737) Google Scholar). NO is synthesized froml-arginine by NO synthase (NOS), a family of enzymes with distinct functional, biochemical, and regulatory properties (1Knowles R.G. Moncada S. Biochem. J. 1994; 298: 249-258Crossref PubMed Scopus (2487) Google Scholar, 2Nathan C. Xie Q. Cell. 1994; 78: 915-918Abstract Full Text PDF PubMed Scopus (2737) Google Scholar). The constitutive NOS isoforms, originally described in endothelial cells and in neurons, produce small amounts of NO in response to an intracellular calcium increase (1Knowles R.G. Moncada S. Biochem. J. 1994; 298: 249-258Crossref PubMed Scopus (2487) Google Scholar, 3Bredt D.S. Snyder S.H. Annu. Rev. Biochem. 1994; 63: 175-195Crossref PubMed Scopus (2127) Google Scholar). Cytokine-inducible NO synthase, whose expression requires protein synthesis, has been demonstrated in a wide variety of mammalian cells and tissues (2Nathan C. Xie Q. Cell. 1994; 78: 915-918Abstract Full Text PDF PubMed Scopus (2737) Google Scholar, 4Nussler A.K. Billiar T.R. J. Leukocyte Biol. 1993; 54: 171-178Crossref PubMed Scopus (828) Google Scholar), and was cloned in different cell types such as murine macrophages (5Lyons C.R. Orloff G.J. Cunninghan J.M. J. Biol. Chem. 1992; 267: 6370-6374Abstract Full Text PDF PubMed Google Scholar, 6Xie Q. Cho H.J. Calaycay J. Mumford R.A. Swiderek K.M. Lee T.D. Ding A. Troso T. C. 1992; PubMed Scopus Google Scholar, D.S. Snyder S.H. S. A. 1992; PubMed Scopus Google Scholar), R.A. A.K. Snyder S.H. Billiar T.R. S. A. 1993; PubMed Scopus Google Scholar), and Moncada S. S. A. 1993; PubMed Scopus Google Scholar). The of NO production by the inducible NOS (NOS-2) is described in murine NO is their and (2Nathan C. Xie Q. Cell. 1994; 78: 915-918Abstract Full Text PDF PubMed Scopus (2737) Google Scholar, PubMed Scopus Google Scholar). the NO by NOS-2 is involved in to and (2Nathan C. Xie Q. Cell. 1994; 78: 915-918Abstract Full Text PDF PubMed Scopus (2737) Google Scholar, 4Nussler A.K. Billiar T.R. J. Leukocyte Biol. 1993; 54: 171-178Crossref PubMed Scopus (828) Google the demonstrated that cells express the NOS, after and J. 1994; 63: PubMed Scopus Google Scholar). pigmented epithelial (RPE) cells Biochem. 1992; PubMed Scopus Google Scholar), Biochem. 1994; PubMed Scopus Google Scholar), and murine 1994; PubMed Scopus Google Scholar, J. S. 1994; Google an inducible of and RPE NOS-2 mRNA is by IFN-γ and LPS and be in the by the of J. S. 1994; Google Scholar). RPE cells cell types with to the of of NO A.K. Billiar T.R. J. Leukocyte Biol. 1993; 54: 171-178Crossref PubMed Scopus (828) Google Scholar). of that in murine macrophages of and to aid LPS in the release of nitrite J. Google Scholar, 1994; PubMed Google Scholar), a of NO, and the expression of NOS-2 mRNA Snyder S.H. J. Biol. Chem. 1993; Full Text PDF PubMed Google Scholar). However, IFN-γ NO release and the of LPS with IFN-γ was the more NOS-2 induction J. Google Scholar, 1994; PubMed Google Scholar, Snyder S.H. J. Biol. Chem. 1993; Full Text PDF PubMed Google of the was to investigate IFN-α and which been described to be to with RPE cells A. 1993; Scopus Google Scholar, 1994; PubMed Scopus Google Scholar), could the production of NO in RPE results of IFN-α and IFN-β markedly NO production by the LPS/IFN-γ in RPE that the inhibitory effect of on NOS-2 could be with a of NOS-2 protein and mRNA This phenomenon is not due to a of IFN-α and IFN-β IFN-γ receptors. was of the activation of the Analysis of the effects of IFN-α on the induction of the IRF-1 and revealed that IFN-α the LPS/IFN-γ-induced IRF-1 mRNA and IRF-2 mRNA in RPE that and the expression of NOS in RPE cells as by nitrite in the of by the that levels of NOS This of the of NOS protein in the and RPE as revealed by Western the by IFN-α and IFN-β of the LPS/IFN-γ-induced increase in NOS mRNA that IFN-α and IFN-β affect the of the inducible of NOS the mRNA The levels with the levels of NOS protein activity. Experiments with revealed that and not the of NOS-2 mRNA in RPE cells with that the decreased expression of NOS-2 after or is not to decreased mRNA of the of the NOS-2 gene to be the The of NO synthase induction was (2Nathan C. Xie Q. Cell. 1994; 78: 915-918Abstract Full Text PDF PubMed Scopus (2737) Google different and such as and and (2Nathan C. Xie Q. Cell. 1994; 78: 915-918Abstract Full Text PDF PubMed Scopus (2737) Google Scholar, S. A. 1993; PubMed Scopus Google Scholar, J. Biochem. PubMed Scopus Google Scholar, C. 1994; Full Text PDF PubMed Scopus Google results with of studies J. Google Scholar, 1994; PubMed Google Scholar, Snyder S.H. J. Biol. Chem. 1993; Full Text PDF PubMed Google Scholar, T. J. Biol. Chem. 1994; Full Text PDF PubMed Google Scholar, A. J. PubMed Scopus Google Scholar), in which IFN-α and IFN-β were to be of NOS of IFN-α or IFN-β on murine macrophages could nitrite release J. Google Scholar, 1994; PubMed Google Scholar), and of IFN-α or IFN-β production could or NOS-2 mRNA in macrophages T. J. Biol. Chem. 1994; Full Text PDF PubMed Google A. J. PubMed Scopus Google Scholar). experiments not the of IFN-α to the nitrite release in macrophages that IFN-α is to nitrite release due to LPS or IFN-γ and effect on LPS/IFN-γ-induced nitrite that the inhibitory effect of IFN-α on NOS-2 induction in RPE cells is the the cell However, phenomenon is not to RPE cells demonstrated the of IFN-α and IFN-β to the nitrite release in macrophages S. PubMed Scopus Google and in S. S. PubMed Google Scholar). macrophages of nitrite production was due to a of NOS-2 mRNA S. J. PubMed Scopus Google Scholar), as in RPE the which the of NOS-2 by IFN-α and that in the signaling by which LPS/IFN-γ NOS-2 gene expression. on the of binding experiments the of NOS induction by was not due to a IFN-α or IFN-β with IFN-γ the the activation of NF-κB and involved in NOS-2 induction Q. C. J. 1993; PubMed Scopus Google Scholar, C. Xie Q. J. 1994; PubMed Scopus Google Scholar, T. J. T. T. J. 1994; PubMed Scopus Google Scholar). by EMSA, that IFN-α did not LPS/IFN-γ-induced NF-κB that the inhibitory effect of on LPS/IFN-γ-induced NOS-2 to be of NF-κB The of NF-κB by could be an inhibitory regulatory NOS induction in RPE as has been the of NOS-2 induction by the in cells C. Google is not the regulatory of NOS-2 gene but could in with such as IRF-1 C. Xie Q. J. 1994; PubMed Scopus Google Scholar, T. J. T. T. J. 1994; PubMed Scopus Google Scholar). demonstrated in that of RPE cells with IFN-γ or with IFN-γ LPS in an increase of IRF-1 mRNA and in an of a which were inhibited in the presence of IFN-α. a similar has been by J. 1994; Google with of the interferon binding demonstrated that IFN-α could the interferon binding protein mRNA in these is that is similar to but that the effect of IRF-1 T. A. T. T. Cell. Full Text PDF PubMed Scopus Google Scholar, J. PubMed Scopus Google Scholar). demonstrated that IRF-2 mRNA is by the IFN-γ decreased IFN-α Furthermore, IFN-α is to the and the LPS/IFN-γ-induced IRF-2 mRNA These results with demonstrated that of NOS-2 IRF-1 and decreased IRF-2 mRNA, the of NOS-2 induction decreased IRF-1 and IRF-2 similar of IRF-1 has been in murine macrophages by NOS and C. J. J. J. PubMed Scopus Google Scholar, C. J. PubMed Scopus Google Scholar). be to that by IRF-2 mRNA and IRF-1 mRNA could the of the which is more than IRF-1 J. T. T. PubMed Scopus Google Scholar). IRF-1 and IRF-2 could the T. A. T. T. Cell. Full Text PDF PubMed Scopus Google Scholar, J. PubMed Scopus Google Scholar). the of IRF-2 and of IRF-1 could the of IRF-2 with the NOS-2 gene in of IRF-1 and could the activation of NOS-2 gene by after IFN-α has been that and in the could be involved in the of the to the of response in 1994; PubMed Scopus Google distinct of that be in response to which and which or to and S. S. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). IFN-α and by on IFN-γ on to a in that results in a in gene expression S. S. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). G.J. K.M. K.M. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google that activation of IRF-1 in response to could be by the of is that IFN-α and -β the of the IFN-γ signaling in RPE by a by a the different 1994; PubMed Scopus Google Scholar, S. S. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar, G.J. K.M. K.M. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google NO as an and molecule in the 1994; PubMed Scopus Google Scholar), the NO release by NOS-2 retinal cell as in the of retinal J. 1993; PubMed Scopus Google or J. J. Google Scholar). by cell types in the of or the production of IFN-α and -β could the NO Xie C. C. 1993; Scopus Google and the defense in the This could a by which the a release of This is in with results in macrophages T.R. Scopus Google Scholar), in which the the induction of by the of IFN-α and However, that of IFN-α and -β on RPE cells by LPS and IFN-γ in to an important in the of response in the Nitric oxide (NO) 1The abbreviations used are: NO, nitric oxide; IRF, interferon regulatory factor; NOS, nitric oxide synthase; RPE, retinal pigmented epithelial; GAPDH, glyceraldehyde-3-phosphate dehydrogenase; NMMA,N G-monomethyl-l-arginine; LPS, lipopolysaccharide; IFN, interferon; PBS, phosphate-buffered saline; PCR, polymerase chain reaction; RT, reverse transcriptase; EMSA, electrophoretic mobility shift assay; h, human; b, bovine. 1The abbreviations used are: NO, nitric oxide; IRF, interferon regulatory factor; NOS, nitric oxide synthase; RPE, retinal pigmented epithelial; GAPDH, glyceraldehyde-3-phosphate dehydrogenase; NMMA,N G-monomethyl-l-arginine; LPS, lipopolysaccharide; IFN, interferon; PBS, phosphate-buffered saline; PCR, polymerase chain reaction; RT, reverse transcriptase; EMSA, electrophoretic mobility shift assay; h, human; b, bovine. is an important signaling molecule that mediates a variety of essential physiological processes including neurotransmission, vasodilatation, and host cell defense (1Knowles R.G. Moncada S. Biochem. J. 1994; 298: 249-258Crossref PubMed Scopus (2487) Google Scholar, 2Nathan C. Xie Q. Cell. 1994; 78: 915-918Abstract Full Text PDF PubMed Scopus (2737) Google Scholar). NO is synthesized froml-arginine by NO synthase (NOS), a family of enzymes with distinct functional, biochemical, and regulatory properties (1Knowles R.G. Moncada S. Biochem. J. 1994; 298: 249-258Crossref PubMed Scopus (2487) Google Scholar, 2Nathan C. Xie Q. Cell. 1994; 78: 915-918Abstract Full Text PDF PubMed Scopus (2737) Google Scholar). The constitutive NOS isoforms, originally described in endothelial cells and in neurons, produce small amounts of NO in response to an intracellular calcium increase (1Knowles R.G. Moncada S. Biochem. J. 1994; 298: 249-258Crossref PubMed Scopus (2487) Google Scholar, 3Bredt D.S. Snyder S.H. Annu. Rev. Biochem. 1994; 63: 175-195Crossref PubMed Scopus (2127) Google Scholar). Cytokine-inducible NO synthase, whose expression requires protein synthesis, has been demonstrated in a wide variety of mammalian cells and tissues (2Nathan C. Xie Q. Cell. 1994; 78: 915-918Abstract Full Text PDF PubMed Scopus (2737) Google Scholar, 4Nussler A.K. Billiar T.R. J. Leukocyte Biol. 1993; 54: 171-178Crossref PubMed Scopus (828) Google Scholar), and was cloned in different cell types such as murine macrophages (5Lyons C.R. Orloff G.J. Cunninghan J.M. J. Biol. Chem. 1992; 267: 6370-6374Abstract Full Text PDF PubMed Google Scholar, 6Xie Q. Cho H.J. Calaycay J. Mumford R.A. Swiderek K.M. Lee T.D. Ding A. Troso T. C. 1992; PubMed Scopus Google Scholar, D.S. Snyder S.H. S. A. 1992; PubMed Scopus Google Scholar), R.A. A.K. Snyder S.H. Billiar T.R. S. A. 1993; PubMed Scopus Google Scholar), and Moncada S. S. A. 1993; PubMed Scopus Google Scholar). The of NO production by the inducible NOS (NOS-2) is described in murine NO is their and (2Nathan C. Xie Q. Cell. 1994; 78: 915-918Abstract Full Text PDF PubMed Scopus (2737) Google Scholar, PubMed Scopus Google Scholar). the NO by NOS-2 is involved in to and (2Nathan C. Xie Q. Cell. 1994; 78: 915-918Abstract Full Text PDF PubMed Scopus (2737) Google Scholar, 4Nussler A.K. Billiar T.R. J. Leukocyte Biol. 1993; 54: 171-178Crossref PubMed Scopus (828) Google Scholar). the demonstrated that cells express the NOS, after and J. 1994; 63: PubMed Scopus Google Scholar). pigmented epithelial (RPE) cells Biochem. 1992; PubMed Scopus Google Scholar), Biochem. 1994; PubMed Scopus Google Scholar), and murine 1994; PubMed Scopus Google Scholar, J. S. 1994; Google an inducible of and RPE NOS-2 mRNA is by IFN-γ and LPS and be in the by the of J. S. 1994; Google Scholar). RPE cells cell types with to the of of NO A.K. Billiar T.R. J. Leukocyte Biol. 1993; 54: 171-178Crossref PubMed Scopus (828) Google Scholar). of that in murine macrophages of and to aid LPS in the release of nitrite J. Google Scholar, 1994; PubMed Google Scholar), a of NO, and the expression of NOS-2 mRNA Snyder S.H. J. Biol. Chem. 1993; Full Text PDF PubMed Google Scholar). However, IFN-γ NO release and the of LPS with IFN-γ was the more NOS-2 induction J. Google Scholar, 1994; PubMed Google Scholar, Snyder S.H. J. Biol. Chem. 1993; Full Text PDF PubMed Google Scholar). The of the was to investigate IFN-α and which been described to be to with RPE cells A. 1993; Scopus Google Scholar, 1994; PubMed Scopus Google Scholar), could the production of NO in RPE results of IFN-α and IFN-β markedly NO production by the LPS/IFN-γ in RPE that the inhibitory effect of on NOS-2 could be with a of NOS-2 protein and mRNA This phenomenon is not due to a of IFN-α and IFN-β IFN-γ receptors. was of the activation of the Analysis of the effects of IFN-α on the induction of the IRF-1 and revealed that IFN-α the LPS/IFN-γ-induced IRF-1 mRNA and IRF-2 mRNA in RPE that and the expression of NOS in RPE cells as by nitrite in the of by the that levels of NOS This of the of NOS protein in the and RPE as revealed by Western the by IFN-α and IFN-β of the LPS/IFN-γ-induced increase in NOS mRNA that IFN-α and IFN-β affect the of the inducible of NOS the mRNA The levels with the levels of NOS protein activity. Experiments with revealed that and not the of NOS-2 mRNA in RPE cells with that the decreased expression of NOS-2 after or is not to decreased mRNA of the of the NOS-2 gene to be the The of NO synthase induction was (2Nathan C. Xie Q. Cell. 1994; 78: 915-918Abstract Full Text PDF PubMed Scopus (2737) Google different and such as and and (2Nathan C. Xie Q. Cell. 1994; 78: 915-918Abstract Full Text PDF PubMed Scopus (2737) Google Scholar, S. A. 1993; PubMed Scopus Google Scholar, J. Biochem. PubMed Scopus Google Scholar, C. 1994; Full Text PDF PubMed Scopus Google results with of studies J. Google Scholar, 1994; PubMed Google Scholar, Snyder S.H. J. Biol. Chem. 1993; Full Text PDF PubMed Google Scholar, T. J. Biol. Chem. 1994; Full Text PDF PubMed Google Scholar, A. J. PubMed Scopus Google Scholar), in which IFN-α and IFN-β were to be of NOS of IFN-α or IFN-β on murine macrophages could nitrite release J. Google Scholar, 1994; PubMed Google Scholar), and of IFN-α or IFN-β production could or NOS-2 mRNA in macrophages T. J. Biol. Chem. 1994; Full Text PDF PubMed Google A. J. PubMed Scopus Google Scholar). experiments not the of IFN-α to the nitrite release in macrophages that IFN-α is to nitrite release due to LPS or IFN-γ and effect on LPS/IFN-γ-induced nitrite that the inhibitory effect of IFN-α on NOS-2 induction in RPE cells is the the cell However, phenomenon is not to RPE cells demonstrated the of IFN-α and IFN-β to the nitrite release in macrophages S. PubMed Scopus Google and in S. S. PubMed Google Scholar). macrophages of nitrite production was due to a of NOS-2 mRNA S. J. PubMed Scopus Google Scholar), as in RPE the which the of NOS-2 by IFN-α and that in the signaling by which LPS/IFN-γ NOS-2 gene expression. on the of binding experiments the of NOS induction by was not due to a IFN-α or IFN-β with IFN-γ the the activation of NF-κB and involved in NOS-2 induction Q. C. J. 1993; PubMed Scopus Google Scholar, C. Xie Q. J. 1994; PubMed Scopus Google Scholar, T. J. T. T. J. 1994; PubMed Scopus Google Scholar). by EMSA, that IFN-α did not LPS/IFN-γ-induced NF-κB that the inhibitory effect of on LPS/IFN-γ-induced NOS-2 to be of NF-κB The of NF-κB by could be an inhibitory regulatory NOS induction in RPE as has been the of NOS-2 induction by the in cells C. Google is not the regulatory of NOS-2 gene but could in with such as IRF-1 C. Xie Q. J. 1994; PubMed Scopus Google Scholar, T. J. T. T. J. 1994; PubMed Scopus Google Scholar). demonstrated in that of RPE cells with IFN-γ or with IFN-γ LPS in an increase of IRF-1 mRNA and in an of a which were inhibited in the presence of IFN-α. a similar has been by J. 1994; Google with of the interferon binding demonstrated that IFN-α could the interferon binding protein mRNA in these is that is similar to but that the effect of IRF-1 T. A. T. T. Cell. Full Text PDF PubMed Scopus Google Scholar, J. PubMed Scopus Google Scholar). demonstrated that IRF-2 mRNA is by the IFN-γ decreased IFN-α Furthermore, IFN-α is to the and the LPS/IFN-γ-induced IRF-2 mRNA These results with demonstrated that of NOS-2 IRF-1 and decreased IRF-2 mRNA, the of NOS-2 induction decreased IRF-1 and IRF-2 similar of IRF-1 has been in murine macrophages by NOS and C. J. J. J. PubMed Scopus Google Scholar, C. J. PubMed Scopus Google Scholar). be to that by IRF-2 mRNA and IRF-1 mRNA could the of the which is more than IRF-1 J. T. T. PubMed Scopus Google Scholar). IRF-1 and IRF-2 could the T. A. T. T. Cell. Full Text PDF PubMed Scopus Google Scholar, J. PubMed Scopus Google Scholar). the of IRF-2 and of IRF-1 could the of IRF-2 with the NOS-2 gene in of IRF-1 and could the activation of NOS-2 gene by after IFN-α has been that and in the could be involved in the of the to the of response in 1994; PubMed Scopus Google distinct of that be in response to which and which or to and S. S. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). IFN-α and by on IFN-γ on to a in that results in a in gene expression S. S. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). G.J. K.M. K.M. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google that activation of IRF-1 in response to could be by the of is that IFN-α and -β the of the IFN-γ signaling in RPE by a by a the different 1994; PubMed Scopus Google Scholar, S. S. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar, G.J. K.M. K.M. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google NO as an and molecule in the 1994; PubMed Scopus Google Scholar), the NO release by NOS-2 retinal cell as in the of retinal J. 1993; PubMed Scopus Google or J. J. Google Scholar). by cell types in the of or the production of IFN-α and -β could the NO Xie C. C. 1993; Scopus Google and the defense in the This could a by which the a release of This is in with results in macrophages T.R. Scopus Google Scholar), in which the the induction of by the of IFN-α and However, that of IFN-α and -β on RPE cells by LPS and IFN-γ in to an important in the of response in the that and the expression of NOS in RPE cells as by nitrite in the of by the that levels of NOS This of the of NOS protein in the and RPE as revealed by Western the by IFN-α and IFN-β of the LPS/IFN-γ-induced increase in NOS mRNA that IFN-α and IFN-β affect the of the inducible of NOS the mRNA The levels with the levels of NOS protein activity. Experiments with revealed that and not the of NOS-2 mRNA in RPE cells with that the decreased expression of NOS-2 after or is not to decreased mRNA of the of the NOS-2 gene to be the The of NO synthase induction was (2Nathan C. Xie Q. Cell. 1994; 78: 915-918Abstract Full Text PDF PubMed Scopus (2737) Google different and such as and and (2Nathan C. Xie Q. Cell. 1994; 78: 915-918Abstract Full Text PDF PubMed Scopus (2737) Google Scholar, S. A. 1993; PubMed Scopus Google Scholar, J. Biochem. PubMed Scopus Google Scholar, C. 1994; Full Text PDF PubMed Scopus Google Scholar). results with of studies J. Google Scholar, 1994; PubMed Google Scholar, Snyder S.H. J. Biol. Chem. 1993; Full Text PDF PubMed Google Scholar, T. J. Biol. Chem. 1994; Full Text PDF PubMed Google Scholar, A. J. PubMed Scopus Google Scholar), in which IFN-α and IFN-β were to be of NOS of IFN-α or IFN-β on murine macrophages could nitrite release J. Google Scholar, 1994; PubMed Google Scholar), and of IFN-α or IFN-β production could or NOS-2 mRNA in macrophages T. J. Biol. Chem. 1994; Full Text PDF PubMed Google A. J. PubMed Scopus Google Scholar). experiments not the of IFN-α to the nitrite release in macrophages that IFN-α is to nitrite release due to LPS or IFN-γ and effect on LPS/IFN-γ-induced nitrite that the inhibitory effect of IFN-α on NOS-2 induction in RPE cells is the the cell However, phenomenon is not to RPE cells demonstrated the of IFN-α and IFN-β to the nitrite release in macrophages S. PubMed Scopus Google and in S. S. PubMed Google Scholar). macrophages of nitrite production was due to a of NOS-2 mRNA S. J. PubMed Scopus Google Scholar), as in RPE the which the of NOS-2 by IFN-α and that in the signaling by which LPS/IFN-γ NOS-2 gene expression. on the of binding experiments the of NOS induction by was not due to a IFN-α or IFN-β with IFN-γ the the activation of NF-κB and involved in NOS-2 induction Q. C. J. 1993; PubMed Scopus Google Scholar, C. Xie Q. J. 1994; PubMed Scopus Google Scholar, T. J. T. T. J. 1994; PubMed Scopus Google Scholar). by EMSA, that IFN-α did not LPS/IFN-γ-induced NF-κB that the inhibitory effect of on LPS/IFN-γ-induced NOS-2 to be of NF-κB The of NF-κB by could be an inhibitory regulatory NOS induction in RPE as has been the of NOS-2 induction by the in cells C. Google Scholar). NF-κB is not the regulatory of NOS-2 gene but could in with such as IRF-1 C. Xie Q. J. 1994; PubMed Scopus Google Scholar, T. J. T. T. J. 1994; PubMed Scopus Google Scholar). demonstrated in that of RPE cells with IFN-γ or with IFN-γ LPS in an increase of IRF-1 mRNA and in an of a which were inhibited in the presence of IFN-α. a similar has been by J. 1994; Google with of the interferon binding demonstrated that IFN-α could the interferon binding protein mRNA in these is that is similar to but that the effect of IRF-1 T. A. T. T. Cell. Full Text PDF PubMed Scopus Google Scholar, J. PubMed Scopus Google Scholar). demonstrated that IRF-2 mRNA is by the IFN-γ decreased IFN-α Furthermore, IFN-α is to the and the LPS/IFN-γ-induced IRF-2 mRNA These results with demonstrated that of NOS-2 IRF-1 and decreased IRF-2 mRNA, the of NOS-2 induction decreased IRF-1 and IRF-2 similar of IRF-1 has been in murine macrophages by NOS and C. J. J. J. PubMed Scopus Google Scholar, C. J. PubMed Scopus Google Scholar). be to that by IRF-2 mRNA and IRF-1 mRNA could the of the which is more than IRF-1 J. T. T. PubMed Scopus Google Scholar). IRF-1 and IRF-2 could the T. A. T. T. Cell. Full Text PDF PubMed Scopus Google Scholar, J. PubMed Scopus Google Scholar). the of IRF-2 and of IRF-1 could the of IRF-2 with the NOS-2 gene in of IRF-1 and could the activation of NOS-2 gene by after IFN-α has been that and in the could be involved in the of the to the of response in 1994; PubMed Scopus Google distinct of that be in response to which and which or to and S. S. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). IFN-α and by on IFN-γ on to a in that results in a in gene expression S. S. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). G.J. K.M. K.M. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google that activation of IRF-1 in response to could be by the of is that IFN-α and -β the of the IFN-γ signaling in RPE by a by a the different 1994; PubMed Scopus Google Scholar, S. S. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar, G.J. K.M. K.M. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). NO as an and molecule in the 1994; PubMed Scopus Google Scholar), the NO release by NOS-2 retinal cell as in the of retinal J. 1993; PubMed Scopus Google or J. J. Google Scholar). by cell types in the of or the production of IFN-α and -β could the NO Xie C. C. 1993; Scopus Google and the defense in the This could a by which the a release of This is in with results in macrophages T.R. Scopus Google Scholar), in which the the induction of by the of IFN-α and However, that of IFN-α and -β on RPE cells by LPS and IFN-γ in to an important in the of response in the the of inducible NOS, the of murine NOS in EMSA, of the and