title: Hepatocyte growth factor (HGF) and the satellite cell response following muscle lengthening contractions in humans.
abstract: The time-courses of satellite cell (SC) activation and protein expression of hepatocyte growth factor (HGF), HGF activator (HGFA), HGFA inhibitor-1 (HAI-1), and HGFA inhibitor-2 (HAI-2) in human skeletal muscle, as well as serum HGF following a single bout of muscle lengthening contractions, were determined. Eight recreationally active participants were recruited for the study. Subjects performed 300 lengthening contractions involving the quadriceps femoris muscles of a single leg at a fixed velocity of 180 degrees/s. Percutaneous muscle biopsies were taken before (PRE) and at 4 h (T4), 24 h (T24), 72 h (T72), and 120 h (T120) following the exercise. The protocol resulted in an increase in the number of SCs [neural cell adhesion molecule (NCAM)-labeled cells] expressed relative to total myonuclei, at T24, compared with both PRE and T4 (P<0.05), and peaked at T72 (approximately 80% increase vs. PRE, P<0.05). HGF protein increased significantly in serum from baseline (PRE) to T4 (P<0.05). Active HGF protein was detected in skeletal muscle at rest [14.4+/-1.3 average integrated density value (IDV)/actin average IDV] and tended to increase at early time-points (P=0.12). HGFA protein increased significantly from PRE to T24 (P<0.05). HAI-1 protein increased significantly from PRE to T24 (P<0.05). HAI-2 (32 kDa) increased significantly from baseline (PRE) by T24 (P<0.05), and also by T72 and T120 (P<0.05). We conclude that a single bout of lengthening muscle contractions is sufficient to activate SCs, which may involve both a local and systemic HGF response to contraction-induced injury.
authors.affiliation: Department of Kinesiology, Ivor Wynne Centre, McMaster University, Hamilton, Ontario L8S 4K1, Canada.
authors.forename: Ciara
authors.initials: C
authors.lastname: O'Reilly
authors.affiliation: Department of Kinesiology, Ivor Wynne Centre, McMaster University, Hamilton, Ontario L8S 4K1, Canada.
authors.forename: Bryon
authors.initials: B
authors.lastname: McKay
authors.affiliation: Department of Kinesiology, Ivor Wynne Centre, McMaster University, Hamilton, Ontario L8S 4K1, Canada.
authors.forename: Stuart
authors.initials: S
authors.lastname: Phillips
authors.affiliation: Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Mark
authors.initials: M
authors.lastname: Tarnopolsky
authors.affiliation: Department of Kinesiology, Ivor Wynne Centre, McMaster University, Hamilton, Ontario L8S 4K1, Canada.|Department of Medical Physics and Applied Radiation Science, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Gianni
authors.initials: G
authors.lastname: Parise
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D015444:Exercise / Q000502:physiology; D005786:Gene Expression Regulation / Q000502:physiology; D017228:Hepatocyte Growth Factor / Q000097:blood*; D006801:Humans; D007797:Laminin / Q000378:metabolism; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000166:cytology* / Q000502:physiology; D019006:Neural Cell Adhesion Molecules / Q000378:metabolism; D053491:Proteinase Inhibitory Proteins, Secretory / Q000378:metabolism; D032496:Satellite Cells, Skeletal Muscle / Q000378:metabolism / Q000502:physiology*; D012697:Serine Endopeptidases / Q000378:metabolism; D013997:Time Factors; D055815:Young Adult
chemical_list: D007797:Laminin; D019006:Neural Cell Adhesion Molecules; D053491:Proteinase Inhibitory Proteins, Secretory; C109149:SPINT1 protein, human; D017228:Hepatocyte Growth Factor; C081092:HGF activator; D012697:Serine Endopeptidases