title: Nitro-oleic acid modulates classical and regulatory activation of macrophages and their involvement in pro-fibrotic responses.
abstract: Inflammation is an immune response triggered by microbial invasion and/or tissue injury. While acute inflammation is directed toward invading pathogens and injured cells, thus enabling tissue regeneration, chronic inflammation can lead to severe pathologies and tissue dysfunction. These processes are linked with macrophage polarization into specific inflammatory "M1-like" or regulatory "M2-like" subsets. Nitro-fatty acids (NO2-FAs), produced endogenously as byproducts of metabolism and oxidative inflammatory conditions, may be useful for treating diseases associated with dysregulated immune homeostasis. The goal of this study was to characterize the role of nitro-oleic acid (OA-NO2) in regulating the functional specialization of macrophages induced by bacterial lipopolysaccharide or interleukin-4, and to reveal specific signaling mechanisms which can account for OA-NO2-dependent modulation of inflammation and fibrotic responses. Our results show that OA-NO2 inhibits lipopolysaccharide-stimulated production of both pro-inflammatory and immunoregulatory cytokines (including transforming growth factor-β) and inhibits nitric oxide and superoxide anion production. OA-NO2 also decreases interleukin-4-induced macrophage responses by inhibiting arginase-I expression and transforming growth factor-β production. These effects are mediated via downregulation of signal transducers and activators of transcription, mitogen-activated protein kinase and nuclear factor-кB signaling responses. Finally, OA-NO2 inhibits fibrotic processes in an in vivo model of angiotensin II-induced myocardial fibrosis by attenuating expression of α-smooth muscle actin, systemic transforming growth factor-β levels and infiltration of both "M1-" and "M2-like" macrophage subsets into afflicted tissue. Overall, the electrophilic fatty acid derivative OA-NO2 modulates a broad range of "M1-" and "M2-like" macrophage functions and represents a potential therapeutic approach to target diseases associated with dysregulated macrophage subsets.
authors.affiliation: Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, Czech Republic.
authors.forename: Gabriela
authors.initials: G
authors.lastname: Ambrozova
authors.affiliation: Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, Czech Republic.|Department of Animal Physiology and Immunology, Masaryk University, Brno, Czech Republic.
authors.forename: Hana
authors.initials: H
authors.lastname: Martiskova
authors.affiliation: Department of Animal Physiology and Immunology, Masaryk University, Brno, Czech Republic.
authors.forename: Adolf
authors.initials: A
authors.lastname: Koudelka
authors.affiliation: Heart Centre, University Hospital of Cologne, Cologne, Germany.
authors.forename: Thorben
authors.initials: T
authors.lastname: Ravekes
authors.affiliation: Heart Centre, University Hospital of Cologne, Cologne, Germany.
authors.forename: Tanja K
authors.initials: TK
authors.lastname: Rudolph
authors.affiliation: Heart Centre, University Hospital of Cologne, Cologne, Germany.|International Clinical Research Center - Center of Biomolecular and Cellular Engineering, St. Anne's University Hospital, Brno, Czech Republic.
authors.forename: Anna
authors.initials: A
authors.lastname: Klinke
authors.affiliation: Heart Centre, University Hospital of Cologne, Cologne, Germany.
authors.forename: Volker
authors.initials: V
authors.lastname: Rudolph
authors.affiliation: Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Freeman
authors.affiliation: Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Steven R
authors.initials: SR
authors.lastname: Woodcock
authors.affiliation: Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, Czech Republic.|International Clinical Research Center - Center of Biomolecular and Cellular Engineering, St. Anne's University Hospital, Brno, Czech Republic.
authors.forename: Lukas
authors.initials: L
authors.lastname: Kubala
authors.affiliation: Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, Czech Republic.|International Clinical Research Center - Center of Biomolecular and Cellular Engineering, St. Anne's University Hospital, Brno, Czech Republic.
authors.forename: Michaela
authors.initials: M
authors.lastname: Pekarova
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D005355:Fibrosis; D015847:Interleukin-4 / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology; D008262:Macrophage Activation / Q000187:drug effects*; D051379:Mice; D008810:Mice, Inbred C57BL; D009206:Myocardium / Q000473:pathology; D009569:Nitric Oxide / Q000096:biosynthesis; D009829:Oleic Acids / Q000494:pharmacology*; D047495:PPAR gamma / Q000502:physiology; D050796:STAT3 Transcription Factor / Q000502:physiology; D013481:Superoxides / Q000378:metabolism
chemical_list: C521487:10-nitro-oleic acid; D008070:Lipopolysaccharides; D009829:Oleic Acids; D047495:PPAR gamma; D050796:STAT3 Transcription Factor; D013481:Superoxides; D015847:Interleukin-4; D009569:Nitric Oxide
keywords: Fibrosis; Inflammation; Macrophage functional specialization; Macrophages; Nitro-fatty acids; Nitro-oleic acid