title: LXA4 actions direct fibroblast function and wound closure.
abstract: Timely resolution of inflammation is crucial for normal wound healing. Resolution of inflammation is an active biological process regulated by specialized lipid mediators including the lipoxins and resolvins. Failure of resolution activity has a major negative impact on wound healing in chronic inflammatory diseases that is manifest as excess fibrosis and scarring. Lipoxins, including Lipoxin A4 (LXA4), have known anti-fibrotic and anti-scarring properties. The goal of this study was to elucidate the impact of LXA4 on fibroblast function. Mouse fibroblasts (3T3 Mus musculus Swiss) were cultured for 72 h in the presence of TGF-β1, to induce fibroblast activation. The impact of exogenous TGF-β1 (1 ng/mL) on LXA4 receptor expression (ALX/FPR2) was determined by flow cytometry. Fibroblast proliferation was measured by bromodeoxyuridine (BrdU) labeling and migration in a "scratch" assay wound model. Expression of α-smooth muscle actin (α-SMA), and collagen types I and III were measured by Western blot. We observed that TGF-β1 up-regulates LXA4 receptor expression, enhances fibroblast proliferation, migration and scratch wound closure. α-SMA levels and Collagen type I and III deposition were also enhanced. LXA4 slowed fibroblast migration and scratch wound closure at early time points (24 h), but wound closure was equal to TGF-β1 alone at 48 and 72 h. LXA4 tended to slow fibroblast proliferation at both concentrations, but had no impact on α-SMA or collagen production by TGF-β1 stimulated fibroblasts. The generalizability of the actions of resolution molecules was examined in experiments repeated with resolvin D2 (RvD2) as the agonist. The activity of RvD2 mimicked the actions of LXA4 in all assays, through an as yet unidentified receptor. The results suggest that mediators of resolution of inflammation enhance wound healing and limit fibrosis in part by modulating fibroblast function.
authors.affiliation: Department of Applied Oral Sciences, Center for Periodontology, The Forsyth Institute, Cambridge, MA, USA; Microbiology Branch, US Army Dental and Trauma Research Detachment, Institute of Surgical Research, JBSA Fort Sam Houston, TX, USA.
authors.forename: Bruno S
authors.initials: BS
authors.lastname: Herrera
authors.affiliation: Department of Applied Oral Sciences, Center for Periodontology, The Forsyth Institute, Cambridge, MA, USA.
authors.forename: Alpdogan
authors.initials: A
authors.lastname: Kantarci
authors.affiliation: Department of Applied Oral Sciences, Center for Periodontology, The Forsyth Institute, Cambridge, MA, USA.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Zarrough
authors.affiliation: Department of Applied Oral Sciences, Center for Periodontology, The Forsyth Institute, Cambridge, MA, USA.
authors.forename: Hatice
authors.initials: H
authors.lastname: Hasturk
authors.affiliation: Microbiology Branch, US Army Dental and Trauma Research Detachment, Institute of Surgical Research, JBSA Fort Sam Houston, TX, USA. Electronic address: kai.p.leung.civ@mail.mil.
authors.forename: Kai P
authors.initials: KP
authors.lastname: Leung
authors.affiliation: Department of Applied Oral Sciences, Center for Periodontology, The Forsyth Institute, Cambridge, MA, USA. Electronic address: tvandyke@forsyth.org.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Van Dyke
mesh_terms: D016475:3T3 Cells; D000199:Actins / Q000378:metabolism; D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D049109:Cell Proliferation / Q000187:drug effects / Q000502:physiology; D024042:Collagen Type I / Q000378:metabolism; D024061:Collagen Type III / Q000378:metabolism; D004281:Docosahexaenoic Acids / Q000494:pharmacology; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D007249:Inflammation / Q000188:drug therapy / Q000473:pathology / Q000503:physiopathology; D044045:Lipoxins / Q000494:pharmacology / Q000502:physiology*; D051379:Mice; D058628:Myofibroblasts / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D044042:Receptors, Formyl Peptide / Q000502:physiology; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology; D014945:Wound Healing / Q000187:drug effects / Q000502:physiology*
chemical_list: D000199:Actins; D024042:Collagen Type I; D024061:Collagen Type III; C469988:Fpr1 protein, mouse; D044045:Lipoxins; D044042:Receptors, Formyl Peptide; D053773:Transforming Growth Factor beta1; C544013:alpha-smooth muscle actin, mouse; C040527:lipoxin A4; C545423:resolvin D2; D004281:Docosahexaenoic Acids
keywords: Collagen; Docosahexaenoic acids; Inflammation; Lipoxins; Resolvin D2; Wound healing