The role of beta 2 adrenoceptor in skeletal muscle regeneration.

Author(s)

Meiricris Tomaz da Silva

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI)
• Defense date: 2014-08-28

Examining board members

Elen Haruka Miyabara; Reury Frank Pereira Bacurau; Cecilia Helena de Azevedo Gouveia Ferreira; Vanessa Morais Freitas; Maria Julia Marques

• Advisor: Elen Haruka Miyabara

Abstract

In this study, we investigated the role of the b2-adrenoceptor in skeletal muscle regeneration. Tibialis anterior muscles from b2-adrenoceptor knockout (b2KO) mice were cryolesioned and analysed after 1, 3, 10, and 21 days. Analysis of structural and contractile aspects, M1 and M2 macrophage profile, cAMP content, and activation of TGF-b/smad signalling elements. Regenerating muscles from b2KO mice showed diminished calibre of regenerating myofibres, decreased muscle contractile function at 10 days when compared with those from wild-type, attenuated augment in cAMP content in muscles at 10 days post-injury, increase in inflammatory process and in the number of macrophages at 3 and 10 days, prevalence of M1 macrophage phenotype, reduction in TbR-I and smad2/3 activation, and in the smad4 expression at 3 days, and an increase in akirin1 expression at 10 days in muscles from b2KO mice when compared to those from wild-type. Our data suggest that the b2-adrenoceptor contributes to the control of the initial stages of muscle regeneration. (AU)