title: VAMP2 is expressed in muscle satellite cells and up-regulated during muscle regeneration.
abstract: Membrane trafficking is one of the most important mechanisms involved in the establishment and maintenance of the forms and functions of the cell. However, it is poorly understood in skeletal muscle cells. In this study, we have focused on vesicle-associated membrane proteins (VAMPs), which are components of the vesicle docking and fusion complex, and have performed immunostaining to investigate the expression of VAMPs in rat skeletal muscle tissue. We have found that VAMP2, but not VAMP1 or VAMP3, is expressed in satellite cells. VAMP2 is also expressed in myofibers in the soleus muscle and nerve endings. This is consistent with previous studies in which VAMP2 has been shown to regulate GLUT4 trafficking in slow-twitch myofibers in soleus muscle and neurotransmitter release in nerve endings. As satellite cells are quiescent myogenic cells, the expression of VAMP2 has further been examined in regenerating muscles after injury by the snake venom, cardiotoxin; we have observed enhanced expression of VAMP2 in immature myotubes with a peak at 3 days after injury. Our findings suggest that VAMP2 plays roles in quiescent satellite cells and is involved in muscle regeneration. The nature of the material transported in the VAMP2-bearing vesicles in satellite cells and myotubes is still under investigation.
authors.affiliation: Department of Neuromuscular and Developmental Anatomy, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma, 371-8511, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Tajika
authors.forename: Mahito
authors.initials: M
authors.lastname: Sato
authors.forename: Tohru
authors.initials: T
authors.lastname: Murakami
authors.forename: Kuniaki
authors.initials: K
authors.lastname: Takata
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yorifuji
mesh_terms: D000818:Animals; D008297:Male; D018485:Muscle Fibers, Skeletal / Q000378:metabolism; D018482:Muscle, Skeletal / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D012038:Regeneration / Q000235:genetics*; D032496:Satellite Cells, Skeletal Muscle / Q000378:metabolism*; D015854:Up-Regulation; D050987:Vesicle-Associated Membrane Protein 1 / Q000378:metabolism; D050988:Vesicle-Associated Membrane Protein 2 / Q000235:genetics* / Q000378:metabolism; D051040:Vesicle-Associated Membrane Protein 3 / Q000378:metabolism
chemical_list: C494706:Vamp2 protein, rat; D050987:Vesicle-Associated Membrane Protein 1; D050988:Vesicle-Associated Membrane Protein 2; D051040:Vesicle-Associated Membrane Protein 3; C494705:vesicle-associated membrane protein 1, rat; C494951:vesicle-associated membrane protein 3, rat