title: Annexin A1 Deficiency does not Affect Myofiber Repair but Delays Regeneration of Injured Muscles.
abstract: Repair and regeneration of the injured skeletal myofiber involves fusion of intracellular vesicles with sarcolemma and fusion of the muscle progenitor cells respectively. In vitro experiments have identified involvement of Annexin A1 (Anx A1) in both these fusion processes. To determine if Anx A1 contributes to these processes during muscle repair in vivo, we have assessed muscle growth and repair in Anx A1-deficient mouse (AnxA1-/-). We found that the lack of Anx A1 does not affect the muscle size and repair of myofibers following focal sarcolemmal injury and lengthening contraction injury. However, the lack of Anx A1 delayed muscle regeneration after notexin-induced injury. This delay in muscle regeneration was not caused by a slowdown in proliferation and differentiation of satellite cells. Instead, lack of Anx A1 lowered the proportion of differentiating myoblasts that managed to fuse with the injured myofibers by days 5 and 7 after notexin injury as compared to the wild type (w.t.) mice. Despite this early slowdown in fusion of Anx A1-/- myoblasts, regeneration caught up at later times post injury. These results establish in vivo role of Anx A1 in cell fusion required for myofiber regeneration and not in intracellular vesicle fusion needed for repair of myofiber sarcolemma.
authors.affiliation: Section on Membrane Biology, Program of Physical Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bldg. 10/Rm. 10D05, 10 Center Dr. Bethesda, Maryland 20892-1855, USA.
authors.forename: Evgenia
authors.initials: E
authors.lastname: Leikina
authors.affiliation: Children's National Medical Center, Center for Genetic Medicine Research, 111 Michigan Avenue, NW, Washington DC 20010-2970, USA.
authors.forename: Aurelia
authors.initials: A
authors.lastname: Defour
authors.affiliation: Section on Membrane Biology, Program of Physical Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bldg. 10/Rm. 10D05, 10 Center Dr. Bethesda, Maryland 20892-1855, USA.
authors.forename: Kamran
authors.initials: K
authors.lastname: Melikov
authors.affiliation: Children's National Medical Center, Center for Genetic Medicine Research, 111 Michigan Avenue, NW, Washington DC 20010-2970, USA.
authors.forename: Jack H
authors.initials: JH
authors.lastname: Van der Meulen
authors.affiliation: Children's National Medical Center, Center for Genetic Medicine Research, 111 Michigan Avenue, NW, Washington DC 20010-2970, USA.|Department of Integrative Systems Biology, George Washington University School of Medicine and Health Sciences, Washington DC, USA.
authors.forename: Kanneboyina
authors.initials: K
authors.lastname: Nagaraju
authors.affiliation: Children's National Medical Center, Center for Genetic Medicine Research, 111 Michigan Avenue, NW, Washington DC 20010-2970, USA.
authors.forename: Shivaprasad
authors.initials: S
authors.lastname: Bhuvanendran
authors.affiliation: Section on Genome Imprinting, Program on Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, USA.
authors.forename: Claudia
authors.initials: C
authors.lastname: Gebert
authors.affiliation: Section on Genome Imprinting, Program on Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, USA.
authors.forename: Karl
authors.initials: K
authors.lastname: Pfeifer
authors.affiliation: Section on Membrane Biology, Program of Physical Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bldg. 10/Rm. 10D05, 10 Center Dr. Bethesda, Maryland 20892-1855, USA.
authors.forename: Leonid V
authors.initials: LV
authors.lastname: Chernomordik
authors.affiliation: Children's National Medical Center, Center for Genetic Medicine Research, 111 Michigan Avenue, NW, Washington DC 20010-2970, USA.|Department of Integrative Systems Biology, George Washington University School of Medicine and Health Sciences, Washington DC, USA.
authors.forename: Jyoti K
authors.initials: JK
authors.lastname: Jaiswal
mesh_terms: D000818:Animals; D017305:Annexin A1 / Q000172:deficiency*; D002459:Cell Fusion; D005260:Female; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D009119:Muscle Contraction / Q000235:genetics; D018485:Muscle Fibers, Skeletal / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000293:injuries / Q000473:pathology / Q000502:physiology*; D012508:Sarcolemma / Q000378:metabolism / Q000648:ultrastructure; D014945:Wound Healing / Q000235:genetics*
chemical_list: D017305:Annexin A1