title: Amelioration of Duchenne muscular dystrophy in mdx mice by elimination of matrix-associated fibrin-driven inflammation coupled to the αMβ2 leukocyte integrin receptor.
abstract: In Duchenne muscular dystrophy (DMD), a persistently altered and reorganizing extracellular matrix (ECM) within inflamed muscle promotes damage and dysfunction. However, the molecular determinants of the ECM that mediate inflammatory changes and faulty tissue reorganization remain poorly defined. Here, we show that fibrin deposition is a conspicuous consequence of muscle-vascular damage in dystrophic muscles of DMD patients and mdx mice and that elimination of fibrin(ogen) attenuated dystrophy progression in mdx mice. These benefits appear to be tied to: (i) a decrease in leukocyte integrin α(M)β(2)-mediated proinflammatory programs, thereby attenuating counterproductive inflammation and muscle degeneration; and (ii) a release of satellite cells from persistent inhibitory signals, thereby promoting regeneration. Remarkably, Fib-gamma(390-396A) (Fibγ(390-396A)) mice expressing a mutant form of fibrinogen with normal clotting function, but lacking the α(M)β(2) binding motif, ameliorated dystrophic pathology. Delivery of a fibrinogen/α(M)β(2) blocking peptide was similarly beneficial. Conversely, intramuscular fibrinogen delivery sufficed to induce inflammation and degeneration in fibrinogen-null mice. Thus, local fibrin(ogen) deposition drives dystrophic muscle inflammation and dysfunction, and disruption of fibrin(ogen)-α(M)β(2) interactions may provide a novel strategy for DMD treatment.
authors.affiliation: Cell Biology Group, Department of Experimental and Health Sciences, Pompeu Fabra University, CIBER on Neurodegenerative Diseases, Barcelona, Spain.
authors.forename: Berta
authors.initials: B
authors.lastname: Vidal
authors.forename: Esther
authors.initials: E
authors.lastname: Ardite
authors.forename: Mònica
authors.initials: M
authors.lastname: Suelves
authors.forename: Vanessa
authors.initials: V
authors.lastname: Ruiz-Bonilla
authors.forename: Anna
authors.initials: A
authors.lastname: Janué
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Flick
authors.forename: Jay L
authors.initials: JL
authors.lastname: Degen
authors.forename: Antonio L
authors.initials: AL
authors.lastname: Serrano
authors.forename: Pura
authors.initials: P
authors.lastname: Muñoz-Cánoves
mesh_terms: D000818:Animals; D005109:Extracellular Matrix / Q000378:metabolism; D005337:Fibrin / Q000378:metabolism*; D005340:Fibrinogen / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D006801:Humans; D007249:Inflammation / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000628:therapy; D007962:Leukocytes / Q000378:metabolism; D008262:Macrophage Activation / Q000187:drug effects; D016177:Macrophage-1 Antigen / Q000378:metabolism*; D008297:Male; D051379:Mice; D018101:Mice, Inbred mdx; D018345:Mice, Knockout; D008817:Mice, Mutant Strains; D008954:Models, Biological; D009137:Muscular Dystrophy, Animal / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D020388:Muscular Dystrophy, Duchenne / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism; D010446:Peptide Fragments / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D012038:Regeneration / Q000502:physiology; D032496:Satellite Cells, Skeletal Muscle / Q000473:pathology / Q000502:physiology
chemical_list: D016177:Macrophage-1 Antigen; D050505:Mutant Proteins; D010446:Peptide Fragments; D005337:Fibrin; D005340:Fibrinogen