Muscarinic M3 receptors on structural cells regulate cigarette smoke-induced neutrophilic airway inflammation in mice.
Anticholinergics, blocking the muscarinic M3 receptor, are effective bronchodilators for patients with chronic obstructive pulmonary disease. Recent evidence from M(3) receptor-deficient mice (M(3)R(-/-)) indicates that M3 receptors also regulate neutrophilic inflammation in response to cigarette smoke (CS). M(3) receptors are present on almost all cell types, and in this study we investigated the relative contribution of M(3) receptors on structural cells vs. inflammatory cells to CS-induced inflammation using bone marrow chimeric mice. Bone marrow chimeras (C56Bl/6 mice) were generated, and engraftment was confirmed after 10 wk. Thereafter, irradiated and nonirradiated control animals were exposed to CS or fresh air for four consecutive days. CS induced a significant increase in neutrophil numbers in nonirradiated and irradiated control animals (4- to 35-fold). Interestingly, wild-type animals receiving M(3)R(-/-) bone marrow showed a similar increase in neutrophil number (15-fold). In contrast, no increase in the number of neutrophils was observed in M3R(-/-) animals receiving wild-type bone marrow. The increase in keratinocyte-derived chemokine (KC) levels was similar in all smoke-exposed groups (2.5- to 5.0-fold). Microarray analysis revealed that fibrinogen-α and CD177, both involved in neutrophil migration, were downregulated in CS-exposed M(3)R(-/-) animals receiving wild-type bone marrow compared with CS-exposed wild-type animals, which was confirmed by RT-qPCR (1.6-2.5 fold). These findings indicate that the M(3) receptor on structural cells plays a proinflammatory role in CS-induced neutrophilic inflammation, whereas the M(3) receptor on inflammatory cells does not. This effect is probably not mediated via KC release, but may involve altered adhesion and transmigration of neutrophils via fibrinogen-α and CD177.
Department of Molecular Pharmacology, University of Groningen, The Netherlands; GRIAC Research Institute, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands l.e.m.kistemaker@rug.nl.
Loes E M
LE
Kistemaker
Section of Stem Cell Biology, Department of Cell Biology, University Medical Center Groningen, University of Groningen, The Netherlands;
Ronald P
RP
van Os
Section of Stem Cell Biology, Department of Cell Biology, University Medical Center Groningen, University of Groningen, The Netherlands;
Albertina
A
Dethmers-Ausema
Department of Molecular Pharmacology, University of Groningen, The Netherlands; GRIAC Research Institute, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
I Sophie T
IS
Bos
Department of Pathology and Medical Biology, University Medical Centre Groningen, Groningen, The Netherlands; GRIAC Research Institute, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
Machteld N
MN
Hylkema
Department of Pulmonary Diseases, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; and GRIAC Research Institute, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
Maarten
M
van den Berge
Department of Pulmonology, Leiden University Medical Center, Leiden, The Netherlands;
Pieter S
PS
Hiemstra
Laboratory of Bioorganic Chemistry, Molecular Signaling Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland;
Jürgen
J
Wess
Department of Molecular Pharmacology, University of Groningen, The Netherlands; GRIAC Research Institute, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
Herman
H
Meurs
Department of Pulmonary Diseases, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; and GRIAC Research Institute, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
Huib A M
HA
Kerstjens
Department of Molecular Pharmacology, University of Groningen, The Netherlands; GRIAC Research Institute, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
Reinoud
R
Gosens
D064591:Allografts; D000818:Animals; D016026:Bone Marrow Transplantation; D054360:Chemokine CXCL1 / Q000235:genetics / Q000378:metabolism; D015536:Down-Regulation / Q000235:genetics; D005340:Fibrinogen / Q000235:genetics / Q000378:metabolism; D007249:Inflammation / Q000209:etiology / Q000378:metabolism / Q000473:pathology; D051379:Mice; D018345:Mice, Knockout; D020556:Neutrophil Infiltration; D009504:Neutrophils / Q000378:metabolism* / Q000473:pathology; D043587:Receptor, Muscarinic M3 / Q000235:genetics / Q000378:metabolism*; D012120:Respiration Disorders / Q000209:etiology / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D012907:Smoking / Q000009:adverse effects* / Q000235:genetics / Q000378:metabolism; D018183:Transplantation Chimera / Q000235:genetics / Q000378:metabolism
D054360:Chemokine CXCL1; C475895:Cxcl1 protein, mouse; D043587:Receptor, Muscarinic M3; C464794:fibrinogen Aalpha; D005340:Fibrinogen
anticholinergics; neutrophil adhesion; nonneuronal acetylcholine