Tags

Type your tag names separated by a space and hit enter

Gene-specific repression of proinflammatory cytokines in stimulated human macrophages by nuclear IκBα.
J Immunol. 2010 Sep 15; 185(6):3685-93.JI

Abstract

We have previously shown that increased nuclear accumulation of IkappaBalpha inhibits NF-kappaB activity and induces apoptosis in human leukocytes. In this study, we wanted to explore the possibility that the nucleocytoplasmic distribution of IkappaBalpha can be used as a therapeutic target for the regulation of NF-kappaB-dependent cytokine synthesis. Treatment of LPS-stimulated human U937 macrophages with an inhibitor of chromosome region maintenance 1-dependent nuclear export, leptomycin B, resulted in the increased nuclear accumulation of IkappaBalpha and inhibition of NF-kappaB DNA binding activity, caused by the nuclear IkappaBalpha-p65 NF-kappaB interaction. Surprisingly, however, whereas mRNA expression and cellular release of TNF-alpha, the beta form of pro-IL-1 (IL-1beta), and IL-6 were inhibited by the leptomycin B-induced nuclear IkappaBalpha, IL-8 mRNA expression and cellular release were not significantly affected. Analysis of in vivo recruitment of p65 NF-kappaB to NF-kappaB-regulated promoters by chromatin immunoprecipitation in U937 cells and human PBMCs indicated that although the p65 recruitment to TNF-alpha, IL-1beta, and IL-6 promoters was inhibited by the nuclear IkappaBalpha, p65 recruitment to IL-8 promoter was not repressed. Chromatin immunoprecipitation analyses using IkappaBalpha and S536 phosphospecific p65 NF-kappaB Abs demonstrated that although the newly synthesized IkappaBalpha induced by postinduction repression is recruited to TNF-alpha, IL-1beta, and IL-6 promoters but not to the IL-8 promoter, S536-phosphorylated p65 is recruited to IL-8 promoter, but not to TNF-alpha, IL-1beta, or IL-6 promoters. Together, these data indicate that the inhibition of NF-kappaB-dependent transcription by nuclear IkappaBalpha in LPS-stimulated macrophages is gene specific and depends on the S536 phosphorylation status of the recruited p65 NF-kappaB.

Authors+Show Affiliations

Department of Biological Sciences, St. John's University, New York, NY 11439, USA.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, N.I.H., Extramural

Language

eng

PubMed ID

20696864

Citation

Ghosh, Chandra C., et al. "Gene-specific Repression of Proinflammatory Cytokines in Stimulated Human Macrophages By Nuclear IκBα." Journal of Immunology (Baltimore, Md. : 1950), vol. 185, no. 6, 2010, pp. 3685-93.
Ghosh CC, Ramaswami S, Juvekar A, et al. Gene-specific repression of proinflammatory cytokines in stimulated human macrophages by nuclear IκBα. J Immunol. 2010;185(6):3685-93.
Ghosh, C. C., Ramaswami, S., Juvekar, A., Vu, H. Y., Galdieri, L., Davidson, D., & Vancurova, I. (2010). Gene-specific repression of proinflammatory cytokines in stimulated human macrophages by nuclear IκBα. Journal of Immunology (Baltimore, Md. : 1950), 185(6), 3685-93. https://doi.org/10.4049/jimmunol.0902230
Ghosh CC, et al. Gene-specific Repression of Proinflammatory Cytokines in Stimulated Human Macrophages By Nuclear IκBα. J Immunol. 2010 Sep 15;185(6):3685-93. PubMed PMID: 20696864.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Gene-specific repression of proinflammatory cytokines in stimulated human macrophages by nuclear IκBα. AU - Ghosh,Chandra C, AU - Ramaswami,Sitharam, AU - Juvekar,Ashish, AU - Vu,Hai-Yen, AU - Galdieri,Luciano, AU - Davidson,Dennis, AU - Vancurova,Ivana, Y1 - 2010/08/09/ PY - 2010/8/11/entrez PY - 2010/8/11/pubmed PY - 2010/12/14/medline SP - 3685 EP - 93 JF - Journal of immunology (Baltimore, Md. : 1950) JO - J Immunol VL - 185 IS - 6 N2 - We have previously shown that increased nuclear accumulation of IkappaBalpha inhibits NF-kappaB activity and induces apoptosis in human leukocytes. In this study, we wanted to explore the possibility that the nucleocytoplasmic distribution of IkappaBalpha can be used as a therapeutic target for the regulation of NF-kappaB-dependent cytokine synthesis. Treatment of LPS-stimulated human U937 macrophages with an inhibitor of chromosome region maintenance 1-dependent nuclear export, leptomycin B, resulted in the increased nuclear accumulation of IkappaBalpha and inhibition of NF-kappaB DNA binding activity, caused by the nuclear IkappaBalpha-p65 NF-kappaB interaction. Surprisingly, however, whereas mRNA expression and cellular release of TNF-alpha, the beta form of pro-IL-1 (IL-1beta), and IL-6 were inhibited by the leptomycin B-induced nuclear IkappaBalpha, IL-8 mRNA expression and cellular release were not significantly affected. Analysis of in vivo recruitment of p65 NF-kappaB to NF-kappaB-regulated promoters by chromatin immunoprecipitation in U937 cells and human PBMCs indicated that although the p65 recruitment to TNF-alpha, IL-1beta, and IL-6 promoters was inhibited by the nuclear IkappaBalpha, p65 recruitment to IL-8 promoter was not repressed. Chromatin immunoprecipitation analyses using IkappaBalpha and S536 phosphospecific p65 NF-kappaB Abs demonstrated that although the newly synthesized IkappaBalpha induced by postinduction repression is recruited to TNF-alpha, IL-1beta, and IL-6 promoters but not to the IL-8 promoter, S536-phosphorylated p65 is recruited to IL-8 promoter, but not to TNF-alpha, IL-1beta, or IL-6 promoters. Together, these data indicate that the inhibition of NF-kappaB-dependent transcription by nuclear IkappaBalpha in LPS-stimulated macrophages is gene specific and depends on the S536 phosphorylation status of the recruited p65 NF-kappaB. SN - 1550-6606 UR - https://www.unboundmedicine.com/medline/citation/20696864/Gene_specific_repression_of_proinflammatory_cytokines_in_stimulated_human_macrophages_by_nuclear_IκBα_ L2 - http://www.jimmunol.org/cgi/pmidlookup?view=long&pmid=20696864 DB - PRIME DP - Unbound Medicine ER -