Insulin modulates myogenesis and muscle atrophy resulting from skin scald burn in young male rats

• Autor(a) principal: Quintana, Hananiah Tardivo
• Data de Publicação: 2020
• Outros Autores: Baptista, Vivianne Izabelle de Araújo, Lazzarin, Mariana Cruz, Antunes, Hanna Karen Moreira, Le Sueur-Maluf, Luciana, Oliveira, Camila Aparecida Machado de, Oliveira, Flavia de
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRN
• Texto Completo: https://repositorio.ufrn.br/handle/123456789/31035
• topic: Burn injury; Insulin; Skeletal muscle; Myogenesis; Atrophy

Burn injuries (BIs) due to scalding are one of the most common accidents among children. BIs greater than 40% of total body surface area are considered extensive and result in local and systemic response. We sought to assess morphological and myogenic mechanisms through both short- and long-term intensive insulin therapies that affect the skeletal muscle after extensive skin BI in young rats. Materials and methods: Wistar rats aged 21 d were distributed into four groups: control (C), control with insulin (C þ I), scald burn injury (SI), and SI with insulin (SI þ I). The SI groups were submitted to a 45% total body surface area burn, and the C þ I and SI þ I groups received insulin (5 UI/Kg/d) for 4 or 14 d. Glucose tolerance and the homeostatic model assessment of insulin resistance index were determined. Gastrocnemius muscles were analyzed for histopathological, morphometric, and immunohistochemical myogenic parameters (Pax7, MyoD, and MyoG); in addition, the expression of genes related to muscle atrophy (MuRF1 and MAFbx) and its regulation (IGF-1) were also assessed. Results: Short-term treatment with insulin favored muscle regeneration by primary myogenesis and decreased muscle atrophy in animals with BIs, whereas the long-term treatment modulated myogenesis by increasing the MyoD protein. Both treatments improved histopathological parameters and secondary myogenesis by increasing the MyoG protein. Conclusions: Treatment with insulin benefits myogenic parameters during regeneration and modulates MuRF1, an important mediator of muscle atrophy