title: Low-level infrared laser modulates muscle repair and chromosome stabilization genes in myoblasts.
abstract: Infrared laser therapy is used for skeletal muscle repair based on its biostimulative effect on satellite cells. However, shortening of telomere length limits regenerative potential in satellite cells, which occurs after each cell division cycle. Also, laser therapy could be more effective on non-physiologic tissues. This study evaluated low-level infrared laser exposure effects on mRNA expression from muscle injury repair and telomere stabilization genes in myoblasts in normal and stressful conditions. Laser fluences were those used in clinical protocols. C2C12 myoblast cultures were exposed to low-level infrared laser (10, 35, and 70 J/cm(2)) in standard or normal (10 %) and reduced (2 %) fetal bovine serum concentrations; total RNA was extracted for mRNA expression evaluation from muscle injury repair (MyoD and Pax7) and chromosome stabilization (TRF1 and TRF2) genes by real time quantitative polymerization chain reaction. Data show that low-level infrared laser increases the expression of MyoD and Pax7 in 10 J/cm(2) fluence, TRF1 expression in all fluences, and TRF2 expression in 70 J/cm(2) fluence in both 10 and 2 % fetal bovine serum. Low-level infrared laser increases mRNA expression from genes related to muscle repair and telomere stabilization in myoblasts in standard or normal and stressful conditions.
authors.affiliation: Laboratório de Pesquisa em Células Tronco, Departamento de Histologia e Embriologia, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Avenida 28 de Setembro, 87, fundos, Vila Isabel, Rio de Janeiro, 20551030, Brazil.
authors.forename: Larissa Alexsandra
authors.initials: LA
authors.lastname: da Silva Neto Trajano
authors.affiliation: Laboratório de Pesquisa em Células Tronco, Departamento de Histologia e Embriologia, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Avenida 28 de Setembro, 87, fundos, Vila Isabel, Rio de Janeiro, 20551030, Brazil.
authors.forename: Ana Carolina
authors.initials: AC
authors.lastname: Stumbo
authors.affiliation: Laboratório de Pesquisa em Células Tronco, Departamento de Histologia e Embriologia, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Avenida 28 de Setembro, 87, fundos, Vila Isabel, Rio de Janeiro, 20551030, Brazil.
authors.forename: Camila Luna
authors.initials: CL
authors.lastname: da Silva
authors.affiliation: Departamento de Biofísica e Biometria, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Avenida 28 de Setembro, 87, fundos, 4° andar, Vila Isabel, Rio de Janeiro, 20551030, Brazil.
authors.forename: Andre Luiz
authors.initials: AL
authors.lastname: Mencalha
authors.affiliation: Departamento de Biofísica e Biometria, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Avenida 28 de Setembro, 87, fundos, 4° andar, Vila Isabel, Rio de Janeiro, 20551030, Brazil. adnfonseca@yahoo.com.br.|Departamento de Ciências Fisiológicas, Instituto Biomédico, Universidade Federal do Estado do Rio de Janeiro, Rua Frei Caneca, 94, Rio de Janeiro, 20211040, Brazil. adnfonseca@yahoo.com.br.
authors.forename: Adenilson S
authors.initials: AS
authors.lastname: Fonseca
mesh_terms: D006801:Humans; D028022:Low-Level Light Therapy / Q000379:methods*; D018482:Muscle, Skeletal / Q000293:injuries* / Q000528:radiation effects*; D032446:Myoblasts / Q000528:radiation effects*; D051763:PAX7 Transcription Factor / Q000096:biosynthesis; D012333:RNA, Messenger / Q000096:biosynthesis*; D012038:Regeneration
chemical_list: D051763:PAX7 Transcription Factor; C497321:PAX7 protein, human; D012333:RNA, Messenger
keywords: Low level laser; MyoD; Pax7; TRF1; TRF2