title: Satellite cells attract monocytes and use macrophages as a support to escape apoptosis and enhance muscle growth.
abstract: Once escaped from the quiescence niche, precursor cells interact with stromal components that support their survival, proliferation, and differentiation. We examined interplays between human myogenic precursor cells (mpc) and monocyte/macrophages (MP), the main stromal cell type observed at site of muscle regeneration. mpc selectively and specifically attracted monocytes in vitro after their release from quiescence, chemotaxis declining with differentiation. A DNA macroarray-based strategy identified five chemotactic factors accounting for 77% of chemotaxis: MP-derived chemokine, monocyte chemoattractant protein-1, fractalkine, VEGF, and the urokinase system. MP showed lower constitutive chemotactic activity than mpc, but attracted monocytes much strongly than mpc upon cross-stimulation, suggesting mpc-induced and predominantly MP-supported amplification of monocyte recruitment. Determination of [3H]thymidine incorporation, oligosomal DNA levels and annexin-V binding showed that MP stimulate mpc proliferation by soluble factors, and rescue mpc from apoptosis by direct contacts. We conclude that once activated, mpc, which are located close by capillaries, initiate monocyte recruitment and interplay with MP to amplify chemotaxis and enhance muscle growth.
authors.affiliation: Institut National de la Santé et de la Recherche Médicale, EMI 00-11, Faculté de Médecine, 8 rue du Général Sarrail, 94000 Créteil, France. benedicte.chazaud@creteil.inserm.fr
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Chazaud
authors.forename: Corinne
authors.initials: C
authors.lastname: Sonnet
authors.forename: Peggy
authors.initials: P
authors.lastname: Lafuste
authors.forename: Guillaume
authors.initials: G
authors.lastname: Bassez
authors.forename: Anne-Cécile
authors.initials: AC
authors.lastname: Rimaniol
authors.forename: Françoise
authors.initials: F
authors.lastname: Poron
authors.forename: François-Jerome
authors.initials: FJ
authors.lastname: Authier
authors.forename: Patrick A
authors.initials: PA
authors.lastname: Dreyfus
authors.forename: Romain K
authors.initials: RK
authors.lastname: Gherardi
mesh_terms: D017209:Apoptosis; D002478:Cells, Cultured; D002630:Chemotactic Factors / Q000235:genetics / Q000378:metabolism; D002633:Chemotaxis; D018920:Coculture Techniques; D017077:Culture Media, Conditioned; D006801:Humans; D008264:Macrophages / Q000166:cytology / Q000502:physiology*; D008969:Molecular Sequence Data; D009000:Monocytes / Q000166:cytology / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000166:cytology / Q000254:growth & development*; D020411:Oligonucleotide Array Sequence Analysis; D032496:Satellite Cells, Skeletal Muscle / Q000166:cytology / Q000502:physiology*
chemical_list: D002630:Chemotactic Factors; D017077:Culture Media, Conditioned