Resveratrol repairs skeletal muscle injury by up-regulating basic fibroblast growth factor and insulin-like growth factor 1 / 中国组织工程研究

ABSTRACT

BACKGROUND: In recent years, resveratrol has been studied a lot on the inhibition of tissue fibrosis, but the effect of resveratrol on the rehabilitation of muscle injury has been rarely reported. OBJECTIVE: To observe the expression of basic fibroblast growth factor (bFGF) and insulin-like growth factor 1 (IGF-1) protein in the repair of acute blunt trauma of the skeletal muscle, and to explore the mechanism by which resveratrol promotes the structural and functional recovery of damaged skeletal muscle. METHODS: Thirty-three New Zealand rabbits were randomly divided into three groups Normal group (n=3), natural recovery group (n=15) and resveratrol group (n=15). The skeletal muscle contusion model was established by blunt violence except for the normal group. The natural recovery group was not treated and the resveratrol group was intragastrically given resveratrol after injury. The animals were euthanized at 1, 3, 7,14, and 21 days after injury. Infiltration of inflammatory cells and formation of collagen fibers were observed using hematoxylin-eosin staining and Masson staining. The expression of bFGF and IGF-1 protein in the skeletal muscle was detected by immunohistochemistry and immunoblotting. RESULTS AND CONCLUSION: (1) Hematoxylin-eosin staining results: In the normal group, the muscle fibers were presented with polygons, regular shape, tight arrangement, muscle nucleus evenly distributed under the sarcolemma, no hyperplasia and pyknosis, and sarcolemma intact. In the injury groups, blood cells were exuded at 1 day, and inflammatory cells infiltrated at 3 days, which reached the maximum at 7 days. The morphology of muscle fibers returned to normal at 21 days after injury. The resveratrol group was better than the natural recovery group in terms of inflammatory cell infiltration and repair time. (2) Masson staining results: There were few collagen fibers in normal muscle cells. After injury, the number of collagen fibers increased with the formation of scar tissue, and reached a peak at 14 days. The content of collagen fibers in the resveratrol group was lower than that in the natural recovery group. (3) Immunohistochemistry and immunoblotting results: The expression of bFGF and IGF-1 protein first increased and then decreased after injury. In both groups, the expression of bFGF and IGF-1 protein reached the peak at 7 days and was still at a high level at 21 days. The resveratrol group had significantly higher bFGF and IGF-1 levels than the natural recovery group (P<0.05). Overall, resveratrol can effectively accelerate the histological healing process and improve the healing quality of rabbit skeletal muscle after blunt trauma. Resveratrol significantly promotes the repair of damaged skeletal muscle by up-regulating bFGF and IGF-1 expression, but not altering the overall change of protein expression during skeletal muscle injury repair.