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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Impaired structural and functional regeneration of skeletal muscles from beta 2-adrenoceptor knockout mice

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Author(s):
Silva, M. T. [1] ; Wensing, L. A. [2] ; Brum, P. C. [3] ; Camara, N. O. [2] ; Miyabara, E. H. [1]
Total Authors: 5
Affiliation:
[1] Univ Sao Paulo, Inst Biomed Sci, Dept Anat, BR-05508000 Sao Paulo - Brazil
[2] Univ Sao Paulo, Inst Biomed Sci, Dept Immunol, BR-05508000 Sao Paulo - Brazil
[3] Univ Sao Paulo, Sch Phys Educ & Sport, Dept Biodynam, BR-05508000 Sao Paulo - Brazil
Total Affiliations: 3
Document type: Journal article
Source: ACTA PHYSIOLOGICA; v. 211, n. 4, p. 617-633, AUG 2014.
Web of Science Citations: 10
Abstract

Aims: beta 2-adrenergic stimulation causes beneficial effects on structure and function of regenerating muscles; thus, the beta 2-adrenoceptor may play an important role in the muscle regenerative process. Here, we investigated the role of the beta 2-adrenoceptor in skeletal muscle regeneration. Methods: Tibialis anterior (TA) muscles from beta 2-adrenoceptor knockout (beta 2KO) mice were cryolesioned and analysed after 1, 3, 10 and 21 days. The role of beta 2-adrenoceptor on regenerating muscles was assessed through the analysis of morphological and contractile aspects, M1 and M2 macrophage profile, cAMP content, and activation of TGF-beta signalling elements. Results: Regenerating muscles from beta 2KO mice showed decreased calibre of regenerating myofibres and reduced muscle contractile function at 10 days when compared with those from wild type. The increase in cAMP content in muscles at 10 days post-cryolesion was attenuated in the absence of the beta 2-adrenoceptor. Furthermore, there was an increase in inflammation and in the number of macrophages in regenerating muscles lacking the beta 2-adrenoceptor at 3 and 10 days, a predominance of M1 macrophage phenotype, a decrease in T beta R-I/Smad2/3 activation, and in the Smad4 expression at 3 days, while akirin1 expression increased at 10 days in muscles from beta 2KO mice when compared to those from wild type. Conclusions: Our results suggest that the beta 2-adrenoceptor contributes to the regulation of the initial phases of muscle regeneration, especially in the control of macrophage recruitment in regenerating muscle through activation of TbR-I/Smad2/3 and reduction in akirin1 expression. These findings have implications for the future development of better therapeutic approaches to prevent or treat muscle injuries. (AU)

FAPESP's process: 12/21238-2 - Skeletal muscle plasticity after injury: role of beta2-adrenoceptor
Grantee:Elen Haruka Miyabara
Support Opportunities: Regular Research Grants
FAPESP's process: 09/53528-7 - Skeletal muscle plasticity after injury and atrophy: influence of heat shock proteins
Grantee:Elen Haruka Miyabara
Support Opportunities: Regular Research Grants
FAPESP's process: 09/12593-0 - Effect of beta 2-adrenergic stimulation on attenuation of skeletal muscle regenerative deficit in old rats.
Grantee:Lucila Hernandes da Silva
Support Opportunities: Scholarships in Brazil - Master