Key points are not available for this paper at this time.
The induction of vascular cell adhesion molecule-1 (VCAM-1) expression by tumor necrosis factor (TNF)-α requires the activation of nuclear factor-κB (NF-κB) via a process involving the phosphorylation and degradation of its cytoplasmic inhibitor, IκBα. We have shown that nitric oxide (NO) decreases VCAM-1 expression via inhibition of NF-κB activation. To determine how NO inhibits NF-κB, we studied the fate of IκBα following TNF-α stimulation in the presence of NO donorsS-nitrosoglutathione and sodium nitroprusside. Activation of NF-κB by TNF-α occurred within 15 min and coincided with rapid degradation of IκBα. Co-treatment with NO donors did not prevent IκBα phosphorylation or degradation. However, after 2 h of TNF-α stimulation, NO donors inhibited NF-κB activation and augmented IκBα resynthesis and nuclear translocation by 2.5- and 3-fold, respectively. This correlated with a 75% reduction in TNF-α-induced VCAM-1 expression. In a time-dependent manner, NO donors alone caused the nuclear translocation of IκBα. To confirm that NO donors have similar effects as endogenously derived NO, murine macrophage-like cells, RAW264.7, were co-cultured with endothelial cells. Induction of RAW264.7-derived NO inhibited lipopolysaccharide-induced endothelial VCAM-1 expression, which was reversed by the NO synthase inhibitorN ω-monomethyl-l-arginine. These findings indicate that NO inhibits NF-κB activation and VCAM-1 expression by increasing the expression and nuclear translocation of IκBα. The induction of vascular cell adhesion molecule-1 (VCAM-1) expression by tumor necrosis factor (TNF)-α requires the activation of nuclear factor-κB (NF-κB) via a process involving the phosphorylation and degradation of its cytoplasmic inhibitor, IκBα. We have shown that nitric oxide (NO) decreases VCAM-1 expression via inhibition of NF-κB activation. To determine how NO inhibits NF-κB, we studied the fate of IκBα following TNF-α stimulation in the presence of NO donorsS-nitrosoglutathione and sodium nitroprusside. Activation of NF-κB by TNF-α occurred within 15 min and coincided with rapid degradation of IκBα. Co-treatment with NO donors did not prevent IκBα phosphorylation or degradation. However, after 2 h of TNF-α stimulation, NO donors inhibited NF-κB activation and augmented IκBα resynthesis and nuclear translocation by 2.5- and 3-fold, respectively. This correlated with a 75% reduction in TNF-α-induced VCAM-1 expression. In a time-dependent manner, NO donors alone caused the nuclear translocation of IκBα. To confirm that NO donors have similar effects as endogenously derived NO, murine macrophage-like cells, RAW264.7, were co-cultured with endothelial cells. Induction of RAW264.7-derived NO inhibited lipopolysaccharide-induced endothelial VCAM-1 expression, which was reversed by the NO synthase inhibitorN ω-monomethyl-l-arginine. These findings indicate that NO inhibits NF-κB activation and VCAM-1 expression by increasing the expression and nuclear translocation of IκBα. The adhesion of circulating leukocytes to the vessel wall is an initiating event in atherogenesis and vascular inflammation (1Cybulsky M.I. Gimbrone Jr., M.A. Science. 1991; 251: 788-791Crossref PubMed Scopus (1405) Google Scholar, 2Davies M.J. Gordon J.L. Gearing A.J. Pigott R. Woolf N. Katz D. Kyriakopoulos A. J. Pathol. 1993; 171: 223-229Crossref PubMed Scopus (693) Google Scholar). Under certain conditions, the “activated” endothelium expresses cell surface adhesion molecules which mediate specific interactions between the endothelium and circulating leukocytes (3Mackay C.R. Imhof B.A. Immunol. Today. 1993; 3: 99-102Abstract Full Text PDF Scopus (243) Google Scholar, 4Smith C.W. Semin. Hematol. 1993; 30: 45-53PubMed Google Scholar). Factors that affect the induction of endothelial cell adhesion molecules such as vascular cell adhesion molecule (VCAM-1) 1The abbreviations used are: VCAM-1, vascular cell adhesion molecule-1; TNF-α, tumor necrosis factor-α; IFN-γ, interferon-γ; mIFN-γ, murine interferon-γ; GSNO,S-nitrosoglutathione; IκBα, inhibitor κBα; LPS, bacterial lipopolysaccharide; LNMA,N ω-monomethyl-l-arginine; NF-κB, nuclear factor-κB; PBS, phosphate-buffered saline; NO, nitric oxide. therefore may be important in regulating vascular inflammatory processes. Recent studies suggest that the activation of the pleotropic transcription factor nuclear factor-κB (NF-κB) is required for the transcriptional induction of endothelial cell adhesion molecules (5Collins T. Read M.A. Neish A.S. Whitley M.Z. Thanos D. Maniatis T. FASEB J. 1995; 9: 1-11Crossref PubMed Scopus (1578) Google Scholar). The activation of NF-κB involves the degradation of its cytoplasmic inhibitor, IκB (6Baeuerle P.A. Baltimore D. Cell. 1996; 87: 13-20Abstract Full Text Full Text PDF PubMed Scopus (2935) Google Scholar, 7Zabel U. Baeuerle P.A. Cell. 1990; 61: 255-265Abstract Full Text PDF PubMed Scopus (305) Google Scholar). Presently, five distinct IκB proteins have been shown to functionally retain NF-κB in the cytoplasm and render it inactive (6Baeuerle P.A. Baltimore D. Cell. 1996; 87: 13-20Abstract Full Text Full Text PDF PubMed Scopus (2935) Google Scholar). These IκB proteins contain ankyrin repeat motifs that mask the nuclear localization sequence of NF-κB subunits such as RelA (p65), c-Rel, and RelB (8Beg A.A. Ruben S.M. Scheinmann R.I. Haskill S. Rosen C.A. Baldwin Jr., A.S. Genes Dev. 1992; 6: 1899-1913Crossref PubMed Scopus (614) Google Scholar, 9Hatada E.N. Naumann M. Scheidereit C. EMBO J. 1993; 12: 2781-2788Crossref PubMed Scopus (79) Google Scholar). Of the different IκB proteins, the best described is IκBα. Following cytokine stimulation, IκBα is phosphorylated by a novel ubiquitinated serine kinase (10Chen Z.J. Parent L. Maniatis T. Cell. 1996; 84: 853-862Abstract Full Text Full Text PDF PubMed Scopus (871) Google Scholar). Phosphorylation of IκBα targets the IκBα for ubiquitination and rapid degradation by 26 S proteasomes (10Chen Z.J. Parent L. Maniatis T. Cell. 1996; 84: 853-862Abstract Full Text Full Text PDF PubMed Scopus (871) Google Scholar, 11Palombella V.J. Rando O.J. Goldberg A.L. Maniatis T. Cell. 1994; 78: 773-785Abstract Full Text PDF PubMed Scopus (1922) Google Scholar). The degradation of IκBα then allows the unbound NF-κB to translocate into the nucleus, where it can transactivate the enhancer elements of many proinflammatory genes (5Collins T. Read M.A. Neish A.S. Whitley M.Z. Thanos D. Maniatis T. FASEB J. 1995; 9: 1-11Crossref PubMed Scopus (1578) Google Scholar). Modulation of IκBα function and expression has been shown to regulate NF-κB activation. For example, the phosphorylation of IκBα is a key regulatory step in the activation of NF-κB (11Palombella V.J. Rando O.J. Goldberg A.L. Maniatis T. Cell. 1994; 78: 773-785Abstract Full Text PDF PubMed Scopus (1922) Google Scholar,12Brown K. Gerstenberger S. Carlson L. Franzoso G. Siebenlist U. Science. 1995; 267: 1485-1488Crossref PubMed Scopus (1317) Google Scholar). Indeed, recent studies indicate that salicylates and antioxidants inhibit NF-κB and endothelial cell activation by preventing IκBα phosphorylation and subsequent degradation (13Kopp E. Ghosh S. Science. 1994; 265: 956-959Crossref PubMed Scopus (1621) Google Scholar, 14Pierce J.W. Read M.A. Ding H. Luscinskas F. Collins T. J. Immunol. 1996; 156: 3961-3969PubMed Google Scholar, 15Sun S.C. Ganchi P.A. Ballard D.W. Greene W.C. Science. 1993; 259: 1912-1915Crossref PubMed Scopus (958) Google Scholar, 16Traenckner E.B. Wilk S. Baeuerle P.A. EMBO J. 1994; 13: 5433-5441Crossref PubMed Scopus (656) Google Scholar). Alternatively, the nuclear accumulation of IκBα resulting from overexpression of IκBα or following stimulation with tumor necrosis factor (TNF)-α has been shown to displace NF-κB from its cognate DNA and terminate NF-κB-mediated transcriptional activity (17Zabel U. Henkel T. dos Santos Silva M. Baeuerle P.A. EMBO J. 1993; 10: 4159-4167Google Scholar, 18Read M.A. Neish A.S. Gerritsen M.E. Collins T. J. Immunol. 1996; 157: 3472-3479PubMed Google Scholar). Finally, some of the anti-inflammatory effects of glucocorticoids may be mediated through their inhibitory effects on NF-κB, since glucocorticoids are known to induce IκBα expression (19Scheinman R.I. Cogswell C.P. Lofquist A.K. Baldwin Jr., A.S. Science. 1995; 270: 283-286Crossref PubMed Scopus (1601) Google Scholar, 20Auphan N. DiDonato J. Rosette C. Helmberg A. Karin M. Science. 1995; 270: 286-288Crossref PubMed Scopus (2169) Google Scholar). We and others have shown that nitric oxide can inhibit NF-κB and endothelial cell activation through non-cGMP-dependent mechanisms (21De Caterina R. Libby P. Peng H.B. Thannickal V.J. Rajavashisth T.B. Gimbrone Jr., M.A. Shin W.S. Liao J.K. J. Clin. Invest. 1995; 96: 60-68Crossref PubMed Scopus (1586) Google Scholar, 22Khan B.V. Harrison D.G. Olbrych M.T. Alexander R.W. Medford R.M. Proc. Natl. Acad. Sci. U. S. A. 1996; 93: 9114-9119Crossref PubMed Scopus (458) Google Scholar). Although NO donors appear to “stabilize” the NF-κB-IκBα heterotrimeric complex (23Peng H.-B. Libby P. Liao J.K. J. Biol. Chem. 1995; 270: 14214-14219Abstract Full Text Full Text PDF PubMed Scopus (638) Google Scholar), the possibility that newly synthesized IκBα could account for this stabilization has not been excluded. Furthermore, it is not known whether the induction of IκBα expression by NO donors could actually lead to an increase in cytoplasmic or nuclear IκBα protein levels. The purpose of this study, therefore, is to determine the mechanism(s) by which NO inhibits of NF-κB activation and VCAM-1 expression in terms of its effects on IκBα phosphorylation, expression, and nuclear accumulation. Medium 199 was purchased from Life Technologies, Inc. Fetal calf serum was purchased from Atlanta Biologicals (Norcross, GA). Recombinant TNF-α was purchased from Endogen (Cambridge, MA). Heparin sulfate, sodium nitrite, alkaline phospatase-conjugated secondary antibody, and p-nitrophenyl phosphate disodium were purchased from Sigma. Sodium nitroprusside (SNP) was purchased from Schwarz Pharma (Mannheim, Germany) and freshly prepared prior to each experiment in 5% dextrose. The NO donor,S-nitrosoglutathione (GSNO), was synthesized from reduced glutathione and sodium nitrite as described by Hart (24Hart T.W. Tetrahedron Lett. 1985; 26: 2013-2016Crossref Scopus (386) Google Scholar). The proteasome inhibitors, MG132 (Z-Leu-Leu-Leu-H) and ALL (N-acetyl-Leu-Leu-Met), were generously provided by Tucker Collins (Brigham 270: 17050-17055Abstract Full Text Full Text PDF PubMed Scopus (161) Google Scholar). For the separated co-culture system, endothelial cells were grown on coverslips coated with 0.1% gelatin in 6-well culture dishes (Falcon, Franklin Lakes, NY). Murine macrophage-like cells, RAW264.7, were grown on inserts with 0.4-μm pore size (Falcon). These inserts were placed above the underlying endothelial cells and shared the same culture medium of Dulbecco's modified Eagle's medium with 10% fetal calf serum and 50 μg/ml endothelial cell growth factor. Endothelial cells were stimulated with TNF-α (1000 units/ml) in the presence and absence of the indicated concentrations of NO donors. The preincubation period was 30 min for GSNO, 10 min for SNP, and 60 min for N-acetylcysteine (30 mm) before TNF-α stimulation. of phosphorylated IκBα was inhibited in the presence of a 26 S proteasome inhibitor, MG132 which was 30 min prior to TNF-α stimulation. Following with the indicated representative endothelial cell plates were for by endothelial cell with than cells were used in For immunoassays, each experiment was in The separated co-culture was stimulated with alone or in in the presence or absence of for were on endothelial cell a VCAM-1 were used in each The were with Following h of stimulation with TNF-α, endothelial cells were on 96-well plates with for min and then incubated with the indicated in Following min of with the antibody at 37 the alkaline secondary antibody was Finally, the phosphate was in an alkaline activity was after 30 min at an of with a CA). Endothelial cells grown on coverslips in the separated co-culture were with at °C for 10 min and then incubated with VCAM-1 antibody for in PBS, a antibody was for Following the cells were incubated with a alkaline antibody and with CA). was a Endothelial cells were grown on gelatin-coated coverslips in 6-well Following with TNF-α or NO donors for the indicated cells were and with at °C for 2 min or with at °C for min was with serum for were incubated with a rabbit polyclonal antibody the NF-κB RelA (p65), or with IκBα for h at antibody was used as secondary min of with the secondary antibody, was for was an were from four The NO was by for nitrite accumulation. following stimulation of the separated co-culture with the indicated a of medium was to of and in was at and nitrite was a of sodium nitrite concentrations from to In some the medium was with to of the to nitrite before the studies indicate that the nitrite to in was than Endothelial cells were by in were prepared as described (23Peng H.-B. Libby P. Liao J.K. J. Biol. Chem. 1995; 270: 14214-14219Abstract Full Text Full Text PDF PubMed Scopus (638) Google Scholar), and protein concentrations were by rabbit polyclonal RelA antibody was incubated with nuclear in 0.1% sodium in for h at were at for min at the was and the was four with of The were then in of 10% for and the was separated by specific with TNF-α and NO endothelial cells were with before of the sodium and to the dishes on an The cell were and for 2 min at cell of and molecular weight were separated by and to fluoride membranes (Immobilon pore was the was the of Scholar). from are as were by of was to a between were by of The NO GSNO, inhibited TNF-α-induced VCAM-1 expression in a 75% inhibition was at a of The of used in mm) did not cell as by cell DNA and To confirm that the effects of the NO donors are to the effects of endogenously derived NO, we a separated co-culture where murine macrophage-like cells, RAW264.7, were grown on culture inserts above endothelial cell the same culture medium In this separated co-culture system, endothelial VCAM-1 expression or RAW264.7-derived NO was 2 and with VCAM-1 expression in endothelial cells not in 2 Murine was inactive in endothelial cells by could not induce NO synthase expression in cells not The of and expression and NO in not in endothelial of NO on endothelial VCAM-1 for accumulation expression of separated co-culture of and endothelial cells was stimulated with the indicated for h as assay was on the co-culture and surface assay for VCAM-1 was on endothelial cell are were in with with and in a The separated co-culture of and endothelial cells was stimulated with the indicated for h as assay was on the co-culture and surface assay for VCAM-1 was on endothelial cell are were in with with and the separated co-culture was stimulated with the of and mIFN-γ, NO was to endothelial VCAM-1 expression was by with stimulation with alone 2 and However, of the inhibitor, to the separated co-culture that been stimulated with and inhibited NO by and augmented endothelial VCAM-1 expression by with the of VCAM-1 expression stimulated with and 2 with alone in endothelial VCAM-1 expression of that endothelial NO can functionally and inhibit VCAM-1 expression 2 of endothelial adhesion molecule expression requires the activation of NF-κB (5Collins T. Read M.A. Neish A.S. Whitley M.Z. Thanos D. Maniatis T. FASEB J. 1995; 9: 1-11Crossref PubMed Scopus (1578) Google Scholar). the activation of NF-κB involves the nuclear translocation of NF-κB we the localization of NF-κB by following TNF-α stimulation in the presence or absence of In endothelial cells, RelA is to the cytoplasm with in the 15 min following TNF-α stimulation, is nuclear accumulation of which was at 2 h with did not prevent the nuclear translocation of RelA after 15 min of TNF-α stimulation 2 h of TNF-α and GSNO, RelA was to the cytoplasm and nucleus, inhibition of NF-κB activation and nuclear to cytoplasmic translocation of NF-κB by with alone did not NF-κB at the 2 h was by the absence of RelA serum was used of RelA These indicate that the inhibitory effects of NO donors on NF-κB activation a 15 and suggest that NO not prevent the degradation of IκBα following TNF-α stimulation. the activation of NF-κB involves the phosphorylation and subsequent degradation of its cytoplasmic inhibitor, IκBα, we the fate of IκBα after stimulation with TNF-α (1000 units/ml) in the presence and absence of with TNF-α for 15 min caused an of IκBα, which was not by with phosphorylated IκBα has a and is to by we endothelial cells with a specific IκBα proteasome inhibitor, MG132 to phosphorylated IκBα. In the presence of stimulation with TNF-α for 15 min to phosphorylated and IκBα. with did not prevent IκBα phosphorylation with that of TNF-α alone with a of or with a NO on IκBα phosphorylation not (30 mm) IκBα and its degradation following TNF-α stimulation. In to a proteasome inhibitor, ALL did not prevent IκBα degradation following IκBα To the effects of NO on IκBα expression, endothelial cells were incubated for with with TNF-α (1000 units/ml) in IκBα degradation by 15 by the or resynthesis of IκBα at 2 h Co-treatment with did not prevent TNF-α-induced IκBα degradation at 15 min did TNF-α-induced IκBα expression by after 2 h to that of TNF-α with alone a time-dependent and increase in IκBα above after and 2 To determine whether NO can affect the localization of IκBα, we studies of IκBα following In endothelial cells, IκBα is to the cytoplasm with to the In a time-dependent manner, with caused a nuclear accumulation of IκBα with serum not The nuclear translocation of IκBα by NO, therefore, occurred in the absence of NF-κB since alone not NF-κB To determine whether the nuclear accumulation of IκBα by NO can terminate NF-κB in the by to we studied the of IκBα in the of nuclear that have been with antibody that IκBα to in the nuclear of endothelial cells following 2 h of TNF-α (1000 units/ml) stimulation This is with the of IκBα in the following and with caused a increase in nuclear IκBα resulting in a increase after h cytoplasmic of the nuclear was by the absence of in the nuclear In IκBα, which is in the cytoplasm of endothelial cells, was not in the nuclear The by which NO inhibits endothelial VCAM-1 expression in via the inhibition of NF-κB (21De Caterina R. Libby P. Peng H.B. Thannickal V.J. Rajavashisth T.B. Gimbrone Jr., M.A. Shin W.S. Liao J.K. J. Clin. Invest. 1995; 96: 60-68Crossref PubMed Scopus (1586) Google Scholar, 22Khan B.V. Harrison D.G. Olbrych M.T. Alexander R.W. Medford R.M. Proc. Natl. Acad. Sci. U. S. A. 1996; 93: 9114-9119Crossref PubMed Scopus (458) Google Scholar). the activation of NF-κB is its with its inhibitor, IκBα, which not and the nuclear translocation of NF-κB (6Baeuerle P.A. Baltimore D. Cell. 1996; 87: 13-20Abstract Full Text Full Text PDF PubMed Scopus (2935) Google Scholar, 7Zabel U. Baeuerle P.A. Cell. 1990; 61: 255-265Abstract Full Text PDF PubMed Scopus (305) Google may displace nuclear NF-κB from its cognate DNA E.B. Wilk S. Baeuerle P.A. EMBO J. 1994; 13: 5433-5441Crossref PubMed Scopus (656) Google Scholar), the of IκBα in the cytoplasm and may be important in the of and of NF-κB activation. of NF-κB activation by IκBα therefore may determine the of VCAM-1 expression in to We that NO inhibits NF-κB activation and VCAM-1 expression by increasing cytoplasmic and nuclear of IκBα. The NO GSNO, has been shown to NO N. J. J. Biol. Chem. 1996; Full Text Full Text PDF PubMed Scopus Google Scholar). Furthermore, the findings of the separated co-culture suggest that the effects of the NO donors is to NO and not some However, we interactions of NO with such as to NO such as T.W. J. P.A. B.A. Proc. Natl. Acad. Sci. U. S. A. 1990; 87: PubMed Scopus Google Scholar). the NO donors used in endogenously derived NO from cells as by cell DNA and it is that in NF-κB activation or VCAM-1 expression were to or effects of Furthermore, we have previously shown that endothelial cell surface proteins, and were not by similar with NO donors (21De Caterina R. Libby P. Peng H.B. Thannickal V.J. Rajavashisth T.B. Gimbrone Jr., M.A. Shin W.S. Liao J.K. J. Clin. Invest. 1995; 96: 60-68Crossref PubMed Scopus (1586) Google Scholar). We that the induction of IκBα by NO or TNF-α in a increase in IκBα protein of IκBα protein in the cytoplasm could the IκBα and retain and “stabilize” the complex in the The of newly synthesized IκBα to cytoplasmic NF-κB therefore may prevent nuclear translocation of NF-κB subunits and VCAM-1 with NO did not inhibit IκBα phosphorylation or degradation by 26 S proteasomes following TNF-α stimulation. This is in to study, which that NO may IκBα (23Peng H.-B. Libby P. Liao J.K. J. Biol. Chem. 1995; 270: 14214-14219Abstract Full Text Full Text PDF PubMed Scopus (638) Google Scholar). In the study, a stimulation that stabilization of IκBα is not for inhibition of of NF-κB in the cytoplasm after IκBα increase in IκBα protein in the may to terminate NF-κB-mediated VCAM-1 transcription by NF-κB from its E.B. Wilk S. Baeuerle P.A. EMBO J. 1994; 13: 5433-5441Crossref PubMed Scopus (656) Google Scholar). This is with that following with NO, and to a TNF-α, IκBα not in the is to nuclear of RelA to IκBα may to RelA from the into the the increase in nuclear IκBα and translocation of NF-κB may be mechanisms by which NO can terminate NF-κB-mediated is not whether this increase in nuclear IκBα is to nuclear translocation of IκBα or as a of in cytoplasmic IκBα levels. The activation of NF-κB following TNF-α stimulation to the transcriptional induction of IκBα via elements in the IκBα R. E. H. F. EMBO J. 1993; 12: PubMed Scopus Google Scholar, R. A. EMBO J. 1993; 12: PubMed Scopus Google Scholar, S. Proc. Natl. Acad. Sci. U. S. A. 1994; PubMed Scopus Google Scholar). The induction of IκBα by NF-κB, therefore, as an for NF-κB-mediated transcription S.C. Ganchi P.A. Ballard D.W. Greene W.C. Science. 1993; 259: 1912-1915Crossref PubMed Scopus (958) Google Scholar, S. Proc. Natl. Acad. Sci. U. S. A. 1994; PubMed Scopus Google Scholar). In the induction of IκBα by NO donors occurred of NF-κB activation in endothelial cells. The induction of IκBα by NO, is similar to the of which have been shown to induce IκBα transcription (19Scheinman R.I. Cogswell C.P. Lofquist A.K. Baldwin Jr., A.S. Science. 1995; 270: 283-286Crossref PubMed Scopus (1601) Google Scholar, 20Auphan N. DiDonato J. Rosette C. Helmberg A. Karin M. Science. 1995; 270: 286-288Crossref PubMed Scopus (2169) Google Scholar). Although the has to be of the and IκBα not to elements R. E. H. F. EMBO J. 1993; 12: PubMed Scopus Google Scholar, R. A. EMBO J. 1993; 12: PubMed Scopus Google Scholar, S. Proc. Natl. Acad. Sci. U. S. A. 1994; PubMed Scopus Google Scholar). it is to whether NO and glucocorticoids a similar transcriptional to the of the IκBα In NO inhibits VCAM-1 expression in cultured vascular endothelial cells via a novel involving the induction and nuclear translocation of IκBα. These effects of NO appear to be distinct from that of antioxidants and which prevent IκBα phosphorylation and degradation (13Kopp E. Ghosh S. Science. 1994; 265: 956-959Crossref PubMed Scopus (1621) Google Scholar, 14Pierce J.W. Read M.A. Ding H. Luscinskas F. Collins T. J. Immunol. 1996; 156: 3961-3969PubMed Google Scholar, 15Sun S.C. Ganchi P.A. Ballard D.W. Greene W.C. Science. 1993; 259: 1912-1915Crossref PubMed Scopus (958) Google Scholar, 16Traenckner E.B. Wilk S. Baeuerle P.A. EMBO J. 1994; 13: 5433-5441Crossref PubMed Scopus (656) Google Scholar). into how NO donors induce IκBα transcription and NF-κB activity may into the of NO in the vascular
Spiecker et al. (Mon,) studied this question.