Growth factors improve muscle healing in vivo

TLDR

Muscle injury is common, and prior in vitro work shows that b‑FGF, IGF‑1, and NGF stimulate myoblast proliferation and fusion. The study aimed to determine whether injecting these growth factors into lacerated gastrocnemius muscle in mice improves healing. Regeneration was evaluated one week after injury by histological staining and quantitative analysis, and muscle function was assessed one month later through contractile measurements. b‑FGF and IGF‑1 significantly enhanced in‑vivo muscle regeneration, and at one month they increased fast‑twitch and tetanic strength, indicating therapeutic potential.

Abstract

Injury to muscles is very common. We have previously observed that basic fibroblast growth factor (b-FGF), insulin growth factor type 1 (IGF-1) and nerve growth factor (NGF) are potent stimulators of the proliferation and fusion of myoblasts in vitro. We therefore injected these growth factors into mice with lacerations of the gastrocnemius muscle. The muscle regeneration was evaluated at one week by histological staining and quantitative histology. Muscle healing was assessed histologically and the contractile properties were measured one month after injury. Our findings showed that b-FGF, IGF and to a less extent NGF enhanced muscle regeneration in vivo compared with control muscle. At one month, muscles treated with IGF-1 and b-FGF showed improved healing and significantly increased fast-twitch and tetanus strengths. Our results suggest that b-FGF and IGF-1 stimulated muscle healing and may have a considerable effect on the treatment of muscle injuries.