Abstract
The activation of pro-inflammatory gene programs by nuclear factor-κB (NF-κB) is primarily regulated through cytoplasmic sequestration of NF-κB by the inhibitor of κB (IκB) family of proteins1. IκBβ, a major isoform of IκB, can sequester NF-κB in the cytoplasm2, although its biological role remains unclear. Although cells lacking IκBβ have been reported3,4, in vivo studies have been limited and suggested redundancy between IκBα and IκBβ5. Like IκBα, IκBβ is also inducibly degraded; however, upon stimulation by lipopolysaccharide (LPS), it is degraded slowly and re-synthesized as a hypophosphorylated form that can be detected in the nucleus6,7,8,9,10,11. The crystal structure of IκBβ bound to p65 suggested this complex might bind DNA12. In vitro, hypophosphorylated IκBβ can bind DNA with p65 and c-Rel, and the DNA-bound NF-κB:IκBβ complexes are resistant to IκBα, suggesting hypophosphorylated, nuclear IκBβ may prolong the expression of certain genes9,10,11. Here we report that in vivo IκBβ serves both to inhibit and facilitate the inflammatory response. IκBβ degradation releases NF-κB dimers which upregulate pro-inflammatory target genes such as tumour necrosis factor-α (TNF-α). Surprisingly, absence of IκBβ results in a dramatic reduction of TNF-α in response to LPS even though activation of NF-κB is normal. The inhibition of TNF-α messenger RNA (mRNA) expression correlates with the absence of nuclear, hypophosphorylated-IκBβ bound to p65:c-Rel heterodimers at a specific κB site on the TNF-α promoter. Therefore IκBβ acts through p65:c-Rel dimers to maintain prolonged expression of TNF-α. As a result, IκBβ−/− mice are resistant to LPS-induced septic shock and collagen-induced arthritis. Blocking IκBβ might be a promising new strategy for selectively inhibiting the chronic phase of TNF-α production during the inflammatory response.
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References
Hayden, M. S. & Ghosh, S. Shared principles in NF-κB signaling. Cell 132, 344–362 (2008)
Malek, S., Chen, Y., Huxford, T. & Ghosh, G. IκBβ, but not IκBα, functions as a classical cytoplasmic inhibitor of NF-κB dimers by masking both NF-κB nuclear localization sequences in resting cells. J. Biol. Chem. 276, 45225–45235 (2001)
Tergaonkar, V., Correa, R. G., Ikawa, M. & Verma, I. M. Distinct roles of IκB proteins in regulating constitutive NF-κB activity. Nature Cell Biol. 7, 921–923 (2005)
Hoffmann, A., Levchenko, A., Scott, M. L. & Baltimore, D. The IκB-NF-κB signaling module: temporal control and selective gene activation. Science 298, 1241–1245 (2002)
Cheng, J. D. et al. Functional redundancy of the nuclear factor κB inhibitors IκBα and IκBβ. J. Exp. Med. 188, 1055–1062 (1998)
Thompson, J. E. et al. IκB-β regulates the persistent response in a biphasic activation of NF-κB. Cell 80, 573–582 (1995)
Weil, R., Laurent-Winter, C. & Israel, A. Regulation of IκBβ degradation. Similarities to and differences from IκBα. J. Biol. Chem. 272, 9942–9949 (1997)
Kerr, L. D. et al. The rel-associated pp40 protein prevents DNA binding of Rel and NF-κB: relationship with IκBβ and regulation by phosphorylation. Genes Dev. 5, 1464–1476 (1991)
Tran, K., Merika, M. & Thanos, D. Distinct functional properties of IκBα and IκBβ. Mol. Cell. Biol. 17, 5386–5399 (1997)
Suyang, H., Phillips, R., Douglas, I. & Ghosh, S. Role of unphosphorylated, newly synthesized IκBβ in persistent activation of NF-κB. Mol. Cell. Biol. 16, 5444–5449 (1996)
Phillips, R. J. & Ghosh, S. Regulation of IκBβ in WEHI 231 mature B cells. Mol. Cell. Biol. 17, 4390–4396 (1997)
Malek, S. et al. X-ray crystal structure of an IκBβ·NF-κB p65 homodimer complex. J. Biol. Chem. 278, 23094–23100 (2003)
Ernst, M. K., Dunn, L. L. & Rice, N. R. The PEST-like sequence of IκBα is responsible for inhibition of DNA binding but not for cytoplasmic retention of c-Rel or RelA homodimers. Mol. Cell. Biol. 15, 872–882 (1995)
Memet, S. et al. IκBε-deficient mice: reduction of one T cell precursor subspecies and enhanced Ig isotype switching and cytokine synthesis. J. Immunol. 163, 5994–6005 (1999)
Hertlein, E. et al. RelA/p65 regulation of IκBβ. Mol. Cell. Biol. 25, 4956–4968 (2005)
Klement, J. F. et al. IκBα deficiency results in a sustained NF-κB response and severe widespread dermatitis in mice. Mol. Cell. Biol. 16, 2341–2349 (1996)
Beg, A. A., Sha, W. C., Bronson, R. T. & Baltimore, D. Constitutive NF-κB activation, enhanced granulopoiesis, and neonatal lethality in IκBα-deficient mice. Genes Dev. 9, 2736–2746 (1995)
Goudeau, B. et al. IκBα/IκBε deficiency reveals that a critical NF-κB dosage is required for lymphocyte survival. Proc. Natl Acad. Sci. USA 100, 15800–15805 (2003)
Hayden, M. S., West, A. P. & Ghosh, S. NF-κB and the immune response. Oncogene 25, 6758–6780 (2006)
Rittirsch, D., Flierl, M. A. & Ward, P. A. Harmful molecular mechanisms in sepsis. Nature Rev. Immunol. 8, 776–787 (2008)
Evans, G. F., Snyder, Y. M., Butler, L. D. & Zuckerman, S. H. Differential expression of interleukin-1 and tumor necrosis factor in murine septic shock models. Circ. Shock 29, 279–290 (1989)
Kontoyiannis, D. et al. Impaired on/off regulation of TNF biosynthesis in mice lacking TNF AU-rich elements: implications for joint and gut-associated immunopathologies. Immunity 10, 387–398 (1999)
Han, J., Brown, T. & Beutler, B. Endotoxin-responsive sequences control cachectin/tumor necrosis factor biosynthesis at the translational level. J. Exp. Med. 171, 465–475 (1990)
Chu, Z. L. et al. Basal phosphorylation of the PEST domain in the IκBβ regulates its functional interaction with the c-rel proto-oncogene product. Mol. Cell. Biol. 16, 5974–5984 (1996)
Kuprash, D. V. et al. Similarities and differences between human and murine TNF promoters in their response to lipopolysaccharide. J. Immunol. 162, 4045–4052 (1999)
Sanjabi, S. et al. Selective requirement for c-Rel during IL-12 P40 gene induction in macrophages. Proc. Natl Acad. Sci. USA 97, 12705–12710 (2000)
Brennan, F. M. & McInnes, I. B. Evidence that cytokines play a role in rheumatoid arthritis. J. Clin. Invest. 118, 3537–3545 (2008)
Miagkov, A. V. et al. NF-κB activation provides the potential link between inflammation and hyperplasia in the arthritic joint. Proc. Natl Acad. Sci. USA 95, 13859–13864 (1998)
Jimi, E. et al. Selective inhibition of NF-κB blocks osteoclastogenesis and prevents inflammatory bone destruction in vivo. Nature Med. 10, 617–624 (2004)
Feldmann, M. Development of anti-TNF therapy for rheumatoid arthritis. Nature Rev. Immunol. 2, 364–371 (2002)
Acknowledgements
We thank A. Lin at the Yale W.M. Keck Biostatistics Resource for analysis of microarray data. S.G. was supported by grants from the National Institutes of Health (R37-AI03343).
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P.R. characterized the mice and performed most of the experiments, M.S.H. performed the immunoprecipitation experiments and helped in writing the paper, M.L. performed collagen-induced arthritis experiments, D.Z. and A.P.W. performed generation of BMDM cells, A.O. performed some experiments, M.L.S. and D.B. generated the knockout mice, C.L. and A.H. performed the RNAse protection assays, and S.G. conceived the study and wrote the paper.
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Rao, P., Hayden, M., Long, M. et al. IκBβ acts to inhibit and activate gene expression during the inflammatory response. Nature 466, 1115–1119 (2010). https://doi.org/10.1038/nature09283
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DOI: https://doi.org/10.1038/nature09283
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