Immunolocalization of myostatin (GDF-8) following musculoskeletal injury and the effects of exogenous myostatin on muscle and bone healing.
The time course and cellular localization of myostatin expression following musculoskeletal injury are not well understood; therefore, the authors evaluated the temporal and spatial localization of myostatin during muscle and bone repair following deep penetrant injury in a mouse model. They then used hydrogel delivery of exogenous myostatin in the same injury model to determine the effects of myostatin exposure on muscle and bone healing. Results showed that a "pool" of intense myostatin staining was observed among injured skeletal muscle fibers 12-24 hr postsurgery and that myostatin was also expressed in the soft callus chondrocytes 4 days following osteotomy. Hydrogel delivery of 10 or 100 µg/ml recombinant myostatin decreased fracture callus cartilage area relative to total callus area in a dose-dependent manner by 41% and 80% (p<0.05), respectively, compared to vehicle treatment. Myostatin treatment also decreased fracture callus total bone volume by 30.6% and 38.8% (p<0.05), with the higher dose of recombinant myostatin yielding the greatest decrease in callus bone volume. Finally, exogenous myostatin treatment caused a significant dose-dependent increase in fibrous tissue formation in skeletal muscle. Together, these findings suggest that early pharmacological inhibition of myostatin is likely to improve the regenerative potential of both muscle and bone following deep penetrant musculoskeletal injury.
School of Dental Medicine, University of Colorado Denver, Denver, Colorado, USA.
Moataz
M
Elkasrawy
David
D
Immel
Xuejun
X
Wen
Xiaoyan
X
Liu
Li-Fang
LF
Liang
Mark W
MW
Hamrick
D000818:Animals; D001842:Bone and Bones / Q000187:drug effects / Q000293:injuries* / Q000378:metabolism; D002146:Bony Callus / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D019902:Chondrocytes / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D005360:Fibula / Q000187:drug effects / Q000293:injuries / Q000378:metabolism; D017102:Fracture Healing / Q000187:drug effects; D020100:Hydrogels; D007150:Immunohistochemistry; D051379:Mice; D018485:Muscle Fibers, Skeletal / Q000378:metabolism; D018482:Muscle, Skeletal / Q000187:drug effects / Q000293:injuries* / Q000378:metabolism; D055435:Myostatin / Q000378:metabolism* / Q000494:pharmacology / Q000627:therapeutic use; D011994:Recombinant Proteins / Q000494:pharmacology / Q000627:therapeutic use; D012038:Regeneration / Q000187:drug effects; D014945:Wound Healing / Q000187:drug effects*; D014950:Wounds, Penetrating / Q000188:drug therapy / Q000378:metabolism*
D020100:Hydrogels; D055435:Myostatin; D011994:Recombinant Proteins