title: Attenuation of inflammatory mediator production by the NF-κB member RelB is mediated by microRNA-146a in lung fibroblasts.
abstract: Lung inflammation can result from exposure to multiple types of inflammatory stimuli. Fibroblasts, key structural cells in the lung that are integral to inflammation and wound healing, produce inflammatory mediators after exposure to stimuli such as IL-1β. We and others have shown that the NF-κB member RelB has anti-inflammatory properties in mice. Little is known, however, about the anti-inflammatory role of RelB in human cells and how it functions. MicroRNAs (miRNAs), a novel class of small, noncoding RNAs, can mediate inflammatory signaling pathways, including NF-κB, through regulation of target gene expression. Our goal was to analyze the anti-inflammatory properties of RelB in human lung fibroblasts. We hypothesized that RelB regulates inflammatory mediator production in lung fibroblasts in part through a mechanism involving miRNAs. To accomplish this, we transfected human lung fibroblasts with a plasmid encoding RelB and small interfering (si)RNA targeting RelB mRNA to overexpress and downregulate RelB, respectively. IL-1β, a powerful proinflammatory stimulus, was used to induce NF-κB-driven inflammatory responses. RelB overexpression reduced IL-1β-induced cyclooxygenase (Cox)-2, PGE₂, and cytokine production, and RelB downregulation increased Cox-2 expression and PGE₂ production. Furthermore, RelB overexpression increased IL-1β-induced expression of miRNA-146a, an NF-κB-dependent miRNA with anti-inflammatory properties, whereas RelB downregulation reduced miRNA-146a. miR-146a overexpression ablated the effects of RelB downregulation on IL-1β-induced Cox-2, PGE₂, and IL-6 production, suggesting that RelB mediates IL-1β-induced inflammatory mediator production in lung fibroblasts through miRNA-146a. RelB and miRNA-146a may therefore be new therapeutic targets in the treatment of lung inflammation caused by various agents and conditions.
authors.affiliation: Department of Environmental Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA.
authors.forename: David H
authors.initials: DH
authors.lastname: McMillan
authors.forename: Collynn F
authors.initials: CF
authors.lastname: Woeller
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Thatcher
authors.forename: Sherry L
authors.initials: SL
authors.lastname: Spinelli
authors.forename: Sanjay B
authors.initials: SB
authors.lastname: Maggirwar
authors.forename: Patricia J
authors.initials: PJ
authors.lastname: Sime
authors.forename: Richard P
authors.initials: RP
authors.lastname: Phipps
mesh_terms: D051546:Cyclooxygenase 2 / Q000096:biosynthesis; D015232:Dinoprostone / Q000096:biosynthesis; D015536:Down-Regulation; D005347:Fibroblasts / Q000378:metabolism; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism*; D008168:Lung / Q000187:drug effects / Q000378:metabolism*; D035683:MicroRNAs / Q000096:biosynthesis / Q000502:physiology*; D051841:Transcription Factor RelB / Q000096:biosynthesis / Q000378:metabolism*
chemical_list: D018836:Inflammation Mediators; C542542:MIRN146 microRNA, human; D035683:MicroRNAs; C497593:RELB protein, human; D051841:Transcription Factor RelB; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D015232:Dinoprostone
keywords: RelB; fibroblasts; inflammation; microRNA-146a; nuclear factor-κB
references.citation: Am J Physiol Cell Physiol. 2002 Aug;283(2):C599-608
references.pmid: 12107070
references.citation: Mol Biol Int. 2011;2011:437301
references.pmid: 22091404
references.citation: Arthritis Res Ther. 2012 Apr 16;14(2):R75
references.pmid: 22507670
references.citation: FEBS Lett. 2009 Oct 20;583(20):3349-55
references.pmid: 19786024
references.citation: Exp Cell Res. 2009 May 1;315(8):1439-47
references.pmid: 19133256
references.citation: Oncogene. 2001 Nov 22;20(53):7722-33
references.pmid: 11753650
references.citation: Invest Ophthalmol Vis Sci. 2011 Jul 01;52(7):4859-65
references.pmid: 21571679
references.citation: Front Biosci (Landmark Ed). 2009 Jan 01;14:1596-605
references.pmid: 19273149
references.citation: Invest Ophthalmol Vis Sci. 2010 Jun;51(6):2976-85
references.pmid: 20053980
references.citation: FASEB J. 2007 Feb;21(2):325-32
references.pmid: 17267386
references.citation: Proc Natl Acad Sci U S A. 2012 May 15;109(20):7865-70
references.pmid: 22550173
references.citation: Am J Physiol Lung Cell Mol Physiol. 2004 Nov;287(5):L981-91
references.pmid: 15234907
references.citation: J Biol Chem. 2012 Jun 22;287(26):21783-95
references.pmid: 22547075
references.citation: J Clin Invest. 2001 Jun;107(12):1529-36
references.pmid: 11413160
references.citation: Am J Respir Crit Care Med. 2012 Oct 15;186(8):740-51
references.pmid: 22923663
references.citation: Am J Pathol. 1997 Aug;151(2):317-22
references.pmid: 9250144
references.citation: Annu Rev Immunol. 2007;25:101-37
references.pmid: 17090225
references.citation: Cell Rep. 2012 Apr 19;1(4):317-24
references.pmid: 22545247
references.citation: Biochem J. 2004 Sep 1;382(Pt 2):393-409
references.pmid: 15214841
references.citation: N Engl J Med. 1997 Apr 10;336(15):1066-71
references.pmid: 9091804
references.citation: Lancet. 2009 May 30;373(9678):1905-17
references.pmid: 19482216
references.citation: Vital Health Stat 2. 1999 Jul;(126):1-119
references.pmid: 10495692
references.citation: Am J Respir Crit Care Med. 2010 Oct 15;182(8):1020-9
references.pmid: 20522791
references.citation: J Periodontol. 2009 May;80(5):833-49
references.pmid: 19405838
references.citation: Am J Respir Cell Mol Biol. 2005 Apr;32(4):311-8
references.pmid: 15668323
references.citation: Am J Physiol Lung Cell Mol Physiol. 2006 Jul;291(1):L19-29
references.pmid: 16443644
references.citation: J Mol Cell Biol. 2011 Jun;3(3):159-66
references.pmid: 21502305
references.citation: Am J Physiol Lung Cell Mol Physiol. 2010 Feb;298(2):L261-9
references.pmid: 19897740
references.citation: Aging (Albany NY). 2009 Apr;1(4):402-11
references.pmid: 20148189
references.citation: J Biol Chem. 2008 Oct 24;283(43):28944-57
references.pmid: 18697742
references.citation: PLoS Pathog. 2009 Dec;5(12):e1000681
references.pmid: 19997496
references.citation: Respir Res. 2010 Oct 28;11:148
references.pmid: 21029443
references.citation: FEBS Lett. 2003 Jul 17;547(1-3):75-9
references.pmid: 12860389
references.citation: Am J Pathol. 2011 Jul;179(1):125-33
references.pmid: 21703398
references.citation: Immunol Invest. 2006;35(3-4):297-325
references.pmid: 16916756
references.citation: Am J Pathol. 1997 Aug;151(2):375-87
references.pmid: 9250151
references.citation: Am J Respir Crit Care Med. 2011 Apr 1;183(7):898-906
references.pmid: 21037022
references.citation: Am J Pathol. 2007 Mar;170(3):855-64
references.pmid: 17322371
references.citation: Cell. 1995 Jan 27;80(2):331-40
references.pmid: 7834753
references.citation: Cell. 2005 Jan 14;120(1):15-20
references.pmid: 15652477
references.citation: J Clin Invest. 2012 Jun;122(6):1973-90
references.pmid: 22622040
references.citation: Mol Cell Biol. 2004 Nov;24(21):9658-67
references.pmid: 15485931
references.citation: Am J Physiol Lung Cell Mol Physiol. 2005 Aug;289(2):L322-8
references.pmid: 15833762
references.citation: Respiration. 2001;68(5):441-8
references.pmid: 11694802
references.citation: J Immunol. 1997 Dec 15;159(12):5964-72
references.pmid: 9550394
references.citation: J Biol Chem. 2003 May 30;278(22):19852-60
references.pmid: 12657634
references.citation: Respirology. 2003 Mar;8(1):17-21
references.pmid: 12856737
references.citation: Biochem Biophys Res Commun. 2008 Jan 18;365(3):583-8
references.pmid: 17996728
references.citation: Nat Immunol. 2010 Sep;11(9):799-805
references.pmid: 20711193
references.citation: Proc Natl Acad Sci U S A. 2006 Aug 15;103(33):12481-6
references.pmid: 16885212
references.citation: Int J Biochem Cell Biol. 1999 Oct;31(10):1209-19
references.pmid: 10582348