title: Comparative effects of low-level laser therapy pre- and post-injury on mRNA expression of MyoD, myogenin, and IL-6 during the skeletal muscle repair.
abstract: This study analyzed the effect of pre-injury and post-injury irradiation with low-level laser therapy (LLLT) on the mRNA expression of myogenic regulatory factors and interleukin 6 (IL-6) during the skeletal muscle repair. Male rats were divided into six groups: control group, sham group, LLLT group, injury group; pre-injury LLLT group, and post-injury LLLT group. LLLT was performed with a diode laser (wavelength 780 nm; output power 40 mW' and total energy 3.2 J). Cryoinjury was induced by two applications of a metal probe cooled in liquid nitrogen directly onto the belly of the tibialis anterior (TA) muscle. After euthanasia, the TA muscle was removed for the isolation of total RNA and analysis of MyoD, myogenin, and IL-6 using real-time quantitative PCR. Significant increases were found in the expression of MyoD mRNA at 3 and 7 days as well as the expression of myogenin mRNA at 14 days in the post-injury LLLT group in comparison to injury group. A significant reduction was found in the expression of IL-6 mRNA at 3 and 7 days in the pre-injury LLLT and post-injury LLLT groups. A significant increase in IL-6 mRNA was found at 14 days in the post-injury LLLT group in comparison to the injury group. LLLT administered following muscle injury modulates the mRNA expression of MyoD and myogenin. Moreover, the both forms of LLLT administration were able to modulate the mRNA expression of IL-6 during the muscle repair process.
authors.affiliation: Postgraduate Program in Rehabilitation Sciences, Universidade Nove de Julho-UNINOVE, Rua Vergueiro, 235/249, Liberdade, CEP 01504-001, São Paulo, SP, Brazil.
authors.forename: Agnelo Neves
authors.initials: AN
authors.lastname: Alves
authors.affiliation: Postgraduate Program in Rehabilitation Sciences, Universidade Nove de Julho-UNINOVE, Rua Vergueiro, 235/249, Liberdade, CEP 01504-001, São Paulo, SP, Brazil.
authors.forename: Beatriz Guimarães
authors.initials: BG
authors.lastname: Ribeiro
authors.affiliation: Postgraduate Program in Biophotonics Applied to Health Sciences, Universidade Nove de Julho-UNINOVE, São Paulo, SP, Brazil.
authors.forename: Kristianne Porta Santos
authors.initials: KP
authors.lastname: Fernandes
authors.affiliation: Postgraduate Program in Rehabilitation Sciences, Universidade Nove de Julho-UNINOVE, Rua Vergueiro, 235/249, Liberdade, CEP 01504-001, São Paulo, SP, Brazil.
authors.forename: Nadhia Helena Costa
authors.initials: NH
authors.lastname: Souza
authors.affiliation: Departament of Molecular Pathology, School of Dentistry, Universidade de São Paulo-FOUSP, São Paulo, SP, Brazil.
authors.forename: Lília Alves
authors.initials: LA
authors.lastname: Rocha
authors.affiliation: Departament of Oral Pathology, School of Dentistry, Universidade de São Paulo-FOUSP, São Paulo, SP, Brazil.
authors.forename: Fabio Daumas
authors.initials: FD
authors.lastname: Nunes
authors.affiliation: Postgraduate Program in Rehabilitation Sciences, Universidade Nove de Julho-UNINOVE, Rua Vergueiro, 235/249, Liberdade, CEP 01504-001, São Paulo, SP, Brazil.|Postgraduate Program in Biophotonics Applied to Health Sciences, Universidade Nove de Julho-UNINOVE, São Paulo, SP, Brazil.
authors.forename: Sandra Kalil
authors.initials: SK
authors.lastname: Bussadori
authors.affiliation: Postgraduate Program in Rehabilitation Sciences, Universidade Nove de Julho-UNINOVE, Rua Vergueiro, 235/249, Liberdade, CEP 01504-001, São Paulo, SP, Brazil. raquel.mesquita@gmail.com.|Postgraduate Program in Biophotonics Applied to Health Sciences, Universidade Nove de Julho-UNINOVE, São Paulo, SP, Brazil. raquel.mesquita@gmail.com.
authors.forename: Raquel Agnelli
authors.initials: RA
authors.lastname: Mesquita-Ferrari
mesh_terms: D000818:Animals; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism; D054023:Lasers, Semiconductor / Q000627:therapeutic use*; D028022:Low-Level Light Therapy; D008297:Male; D018482:Muscle, Skeletal / Q000293:injuries / Q000502:physiology*; D017570:MyoD Protein / Q000235:genetics / Q000378:metabolism; D018008:Myogenin / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012038:Regeneration / Q000528:radiation effects*; D014945:Wound Healing / Q000528:radiation effects
chemical_list: D015850:Interleukin-6; D017570:MyoD Protein; C503803:Myog protein, rat; D018008:Myogenin; D012333:RNA, Messenger
keywords: Cytokines; Low-level laser therapy; Muscle injury; Myogenic factors; Regeneration; Satellite cells