title: Reactivity of rat bone marrow-derived macrophages to neurotransmitter stimulation in the context of collagen II-induced arthritis.
abstract: BACKGROUND
  Numerous observations indicate that rheumatoid arthritis (RA) has a bone marrow component. In parallel, local synovial changes depend on neuronal components of the peripheral sympathetic nervous system. Here, we wanted to analyze whether collagen II-induced arthritis (CIA) has an impact on number, adhesion, apoptosis, and proliferation of the macrophage subset of bone marrow cells and how alterations in neurotransmitter microenvironment affect these properties.
  
  
  METHODS
  Bone marrow-derived macrophages (BMMs) were isolated from Dark Agouti rats at different stages of CIA, and number, adhesion, caspase 3/7 activity, and proliferation were analyzed in the presence of acetylcholine (ACh), noradrenaline (NA), and vasoactive intestinal peptide (VIP).
  
  
  RESULTS
  Opposed to enhanced CD11b(+) (cluster of differentiation 11b-positive) and EMR1(+) (epidermal growth factor-like module-containing mucin-like hormone receptor-like 1-positive) cells, characterizing the macrophage subset, in native bone marrow of rats with acute inflammatory arthritis, we found decreased numbers of CIA macrophages after enrichment and culture in comparison with healthy (control) animals. Adhesion studies revealed significantly reduced attachment to plastic in acute arthritis and collagen type I and fibronectin in chronic arthritis. Additionally, we found a strong reduction in proliferation of BMMs at CIA onset and in the chronic phase of CIA. Apoptosis remained unaffected. Neurotransmitter stimulation profoundly affected proliferation, adhesion, and apoptosis of BMMs from CIA and control rats, depending on disease time point. Cultured BMMs from CIA and control animals expressed neurotransmitter receptors for ACh, VIP and NA, but the expression profile seemed not to be affected by CIA.
  
  
  CONCLUSIONS
  Induction of CIA distinctly inhibits proliferation of BMMs in low- and non-inflammatory phases and reduces attachment to plastic at the acute inflammatory arthritis stage and adhesion to collagen I and fibronectin at the chronic stage. Influence of neurotransmitter stimulation on adhesion, apoptosis, and proliferation is altered by CIA depending on disease stage. We suggest an altered reactivity of BMMs to neurotransmitter stimulation caused by CIA and maybe also by aging.
authors.affiliation: Experimental Orthopedics, Centre for Medical Biotechnology, Biopark I, University of Regensburg, Josef-Engert-Str. 9, 93053, Regensburg, Germany. dominique.muschter@klinik.uni-regensburg.de.|Department of Orthopedic Surgery, University of Regensburg, Kaiser-Karl V-Allee 3, 93077, Bad Abbach, Germany. dominique.muschter@klinik.uni-regensburg.de.
authors.forename: Dominique
authors.initials: D
authors.lastname: Muschter
authors.affiliation: Experimental Orthopedics, Centre for Medical Biotechnology, Biopark I, University of Regensburg, Josef-Engert-Str. 9, 93053, Regensburg, Germany. claudia.goettl@klinik.uni-regensburg.de.|Department of Orthopedic Surgery, University of Regensburg, Kaiser-Karl V-Allee 3, 93077, Bad Abbach, Germany. claudia.goettl@klinik.uni-regensburg.de.
authors.forename: Claudia
authors.initials: C
authors.lastname: Göttl
authors.affiliation: Experimental Orthopedics, Centre for Medical Biotechnology, Biopark I, University of Regensburg, Josef-Engert-Str. 9, 93053, Regensburg, Germany. mandy.vogel@klinik.uni-regensburg.de.|Department of Orthopedic Surgery, University of Regensburg, Kaiser-Karl V-Allee 3, 93077, Bad Abbach, Germany. mandy.vogel@klinik.uni-regensburg.de.
authors.forename: Mandy
authors.initials: M
authors.lastname: Vogel
authors.affiliation: Department of Orthopedic Surgery, University of Regensburg, Kaiser-Karl V-Allee 3, 93077, Bad Abbach, Germany. joachim.grifka@klinik.uni-regensburg.de.
authors.forename: Joachim
authors.initials: J
authors.lastname: Grifka
authors.affiliation: Laboratory of Experimental Rheumatology and Neuroendocrine Immunology, Department of Internal Medicine I, University Hospital Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany. rainer.straub@klinik.uni-regensburg.de.
authors.forename: Rainer H
authors.initials: RH
authors.lastname: Straub
authors.affiliation: Experimental Orthopedics, Centre for Medical Biotechnology, Biopark I, University of Regensburg, Josef-Engert-Str. 9, 93053, Regensburg, Germany. susanne.graessel@klinik.uni-regensburg.de.|Department of Orthopedic Surgery, University of Regensburg, Kaiser-Karl V-Allee 3, 93077, Bad Abbach, Germany. susanne.graessel@klinik.uni-regensburg.de.
authors.forename: Susanne
authors.initials: S
authors.lastname: Grässel
mesh_terms: D000818:Animals; D001169:Arthritis, Experimental / Q000276:immunology* / Q000473:pathology; D001172:Arthritis, Rheumatoid / Q000276:immunology* / Q000473:pathology; D001854:Bone Marrow Cells / Q000276:immunology; D002448:Cell Adhesion / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D005260:Female; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D008264:Macrophages / Q000187:drug effects / Q000276:immunology* / Q000473:pathology; D018377:Neurotransmitter Agents / Q000494:pharmacology*; D016133:Polymerase Chain Reaction; D051381:Rats
chemical_list: D018377:Neurotransmitter Agents