title: Low-level laser irradiation modulates cell viability and creatine kinase activity in C2C12 muscle cells during the differentiation process.
abstract: Low-level laser irradiation (LLLI) is increasingly used to treat musculoskeletal disorders, with satisfactory results described in the literature. Skeletal muscle satellite cells play a key role in muscle regeneration. The aim of the present study was to evaluate the effect of LLLI on cell viability, creatine kinase (CK) activity, and the expression of myogenic regulatory factors in C2C12 myoblasts during the differentiation process. C2C12 cells were cultured in Dulbecco's modified Eagle's medium (DMEM) containing 2% horse serum and submitted to irradiation with GaAlAs diode laser (wavelength, 780 nm; output power, 10 mW; energy density, 5 J/cm2). Cell viability and the expression of myogenic regulatory factors were assessed 24, 48, and 72 h after irradiation by 3-(4,5-dimethylthiazol-2-yl)-2,5,-diphenyltetrazolium bromide (MTT) assay and quantitative real-time polymerase chain reaction (RT-qPCR), respectively. CK activity was analyzed at 24 and 72 h. An increase in cell viability was found in the laser group in comparison to the control group at all evaluation times. CK activity was significantly increased in the laser group at 72 h. Myogenin messenger RNA (mRNA) demonstrated a tendency toward an increase in the laser group, but the difference in comparison to the control group was non-significant. In conclusion, LLLI was able to modulate cell viability and CK activity in C2C12 myoblasts during the differentiation process.
authors.affiliation: Postgraduate Program in Rehabilitation Sciences and Biophotonics Applied to Health Sciences, Universidade Nove de Julho (UNINOVE), Rua Vergueiro, 235/249, Liberdade, São Paulo, SP, 01504-001, Brazil. raquel.mesquita@gmail.com.
authors.forename: Raquel Agnelli
authors.initials: RA
authors.lastname: Mesquita-Ferrari
authors.affiliation: Postgraduate Program in Rehabilitation Sciences and Biophotonics Applied to Health Sciences, Universidade Nove de Julho (UNINOVE), Rua Vergueiro, 235/249, Liberdade, São Paulo, SP, 01504-001, Brazil.
authors.forename: Agnelo Neves
authors.initials: AN
authors.lastname: Alves
authors.affiliation: Postgraduate Program in Rehabilitation Sciences and Biophotonics Applied to Health Sciences, Universidade Nove de Julho (UNINOVE), Rua Vergueiro, 235/249, Liberdade, São Paulo, SP, 01504-001, Brazil.
authors.forename: Vinicius
authors.initials: V
authors.lastname: de Oliveira Cardoso
authors.affiliation: Postgraduate Program in Rehabilitation Sciences and Biophotonics Applied to Health Sciences, Universidade Nove de Julho (UNINOVE), Rua Vergueiro, 235/249, Liberdade, São Paulo, SP, 01504-001, Brazil.
authors.forename: Paola Pelegrineli
authors.initials: PP
authors.lastname: Artilheiro
authors.affiliation: Postgraduate Program in Rehabilitation Sciences and Biophotonics Applied to Health Sciences, Universidade Nove de Julho (UNINOVE), Rua Vergueiro, 235/249, Liberdade, São Paulo, SP, 01504-001, Brazil.
authors.forename: Sandra Kalil
authors.initials: SK
authors.lastname: Bussadori
authors.affiliation: Departament of Molecular Pathology, School of Dentistry, University of São Paulo, Av. Professor Lineu Prestes, 2227, Cidade Universitária, São Paulo, 05508-000, SP, Brazil.
authors.forename: Lilia Alves
authors.initials: LA
authors.lastname: Rocha
authors.affiliation: Department of Oral Pathology, School of Dentistry, University of São Paulo, Av. Professor Lineu Prestes, 2227, Cidade Universitária, São Paulo, 05508-000, SP, Brazil.
authors.forename: Fábio Daumas
authors.initials: FD
authors.lastname: Nunes
authors.affiliation: Postgraduate Program in Rehabilitation Sciences and Biophotonics Applied to Health Sciences, Universidade Nove de Julho (UNINOVE), Rua Vergueiro, 235/249, Liberdade, São Paulo, SP, 01504-001, Brazil.
authors.forename: Kristianne Porta Santos
authors.initials: KP
authors.lastname: Fernandes
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000235:genetics / Q000528:radiation effects*; D002470:Cell Survival / Q000528:radiation effects; D002478:Cells, Cultured; D003402:Creatine Kinase / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000528:radiation effects; D028022:Low-Level Light Therapy; D051379:Mice; D017570:MyoD Protein / Q000235:genetics / Q000378:metabolism; D032446:Myoblasts / Q000166:cytology* / Q000201:enzymology* / Q000528:radiation effects; D018008:Myogenin / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D017570:MyoD Protein; D018008:Myogenin; D012333:RNA, Messenger; D003402:Creatine Kinase
keywords: C2C12 differentiation; Cell viability; Creatine kinase; Low-level laser; Myoblasts