title: Satellite cells produce neural chemorepellent semaphorin 3A upon muscle injury.
abstract: Regenerative mechanisms that regulate intramuscular motor innervation. including configuration of the neuromuscular connections are thought to reside in the spatiotemporal expression of axon-guidance molecules. Our previous studies proposed a heretofore unexplored role of satellite cells as a key source of a secreted neural chemorepellent semaphorin 3A (Sema3A) expression. In order to verify this concept, there is still a critical need to provide direct evidence to show the up-regulation of Sema3A protein in satellite cells in vivo upon muscle injury. The present study employed a Sema3A/MyoD double-immunohistochemical staining for cryo-sections prepared from cardiotoxin injected gastrocnemius muscle of adult mouse lower hind-limb. Results clearly demonstrated that Sema3A expression was up-regulated in myogenic differentiation-positive satellite cells at 4-12 days post-injury period, the time that corresponds to the cell differentiation phase characterized by increasing myogenin messenger RNA expression. This direct proof encourages a possible implication of satellite cells in the spatiotemporal regulation of extracellular Sema3A concentrations, which potentially ensures coordinating a delay in neurite sprouting and re-attachment of motoneuron terminals onto damaged muscle fibers early in muscle regeneration in synchrony with recovery of muscle-fiber integrity.
authors: Department of Animal and Marine Bioresource Sciences, Graduate School of Agriculture, Fukuoka, Japan.
authors: Yusuke
authors: Y
authors: Sato
authors: Mai-Khoi Q
authors: MK
authors: DO
authors: Takahiro
authors: T
authors: Suzuki
authors: Hideaki
authors: H
authors: Ohtsubo
authors: Wataru
authors: W
authors: Mizunoya
authors: Mako
authors: M
authors: Nakamura
authors: Mitsuhiro
authors: M
authors: Furuse
authors: Yoshihide
authors: Y
authors: Ikeuchi
authors: Ryuichi
authors: R
authors: Tatsumi
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D004179:Cobra Cardiotoxin Proteins / Q000008:administration & dosage / Q000633:toxicity; D007273:Injections, Intramuscular; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018482:Muscle, Skeletal / Q000166:cytology / Q000293:injuries* / Q000378:metabolism* / Q000502:physiology; D012038:Regeneration; D032496:Satellite Cells, Skeletal Muscle / Q000166:cytology / Q000378:metabolism* / Q000502:physiology*; D040121:Semaphorin-3A / Q000378:metabolism* / Q000502:physiology; D015854:Up-Regulation
chemical_list: D004179:Cobra Cardiotoxin Proteins; D040121:Semaphorin-3A