Early regeneration of whole skeletal muscle grafts is unaffected by overexpression of IGF-1 in MLC/mIGF-1 transgenic mice.
Early myogenic events in regenerating whole muscle grafts were compared between transgenic MLC/mIGF-1 mice with skeletal muscle-specific overexpression of the Exon-1 Ea isoform of insulin-like growth factor-1 (mIGF-1) and control FVB mice, from day 3 to day 21 after transplantation. Immunocytochemistry with antibodies against desmin showed that skeletal muscle-specific overexpression of IGF-1 did not affect the pattern of myoblast activation or proliferation or the onset and number of myotubes formed in regenerating whole muscle grafts. Hypertrophied myotubes were observed in MLC/mIGF grafts at day 7 after transplantation, although such hypertrophy was transient, and the transgenic and control grafts had a similar appearance at later time points (days 10, 14, and 21). Immunostaining with antibodies to platelet endothelial cell adhesion molecule-1, which identifies endothelial cells, demonstrated no difference in the formation of new vascular network in grafts of transgenic and control mice. Skeletal muscle-specific overexpression of mIGF-1 does not appear to stimulate the early events associated with myogenesis during regeneration of whole muscle grafts.
Shavlakadze
Thea
T
School of Anatomy and Human Biology, University of Western Australia, Crawley, Western Australia 6009.
Davies
Marilyn
M
White
Jason D
JD
Grounds
Miranda D
MD
D000818:Animals; D002452:Cell Count; D007150:Immunohistochemistry; D007334:Insulin-Like Growth Factor I / Q000096:biosynthesis* / Q000235:genetics*; D051379:Mice; D008822:Mice, Transgenic; D018485:Muscle Fibers, Skeletal / Q000166:cytology; D018482:Muscle, Skeletal / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D012038:Regeneration; D014182:Transplantation, Autologous
D007334:Insulin-Like Growth Factor I