title: Photobiomodulation Protects and Promotes Differentiation of C2C12 Myoblast Cells Exposed to Snake Venom.
abstract: BACKGROUND
  Snakebites is a neglected disease and in Brazil is considered a serious health problem, with the majority of the snakebites caused by the genus Bothrops. Antivenom therapy and other first-aid treatments do not reverse local myonecrose which is the main sequel caused by the envenomation. Several studies have shown the effectiveness of low level laser (LLL) therapy in reducing local myonecrosis induced by Bothropic venoms, however the mechanism involved in this effect is unknown. In this in vitro study, we aimed to analyze the effect of LLL irradiation against cytotoxicity induced by Bothrops jararacussu venom on myoblast C2C12 cells.
  
  
  METHODS
  C2C12 were utilized as a model target and were incubated with B. jararacussu venom (12.5 μg/mL) and immediately irradiated with LLL at wavelength of red 685 nm or infrared 830 nm with energy density of 2.0, 4.6 and 7.0 J/cm2. Effects of LLL on cellular responses of venom-induced cytotoxicity were examined, including cell viability, measurement of cell damage and intra and extracellular ATP levels, expression of myogenic regulatory factors, as well as cellular differentiation.
  
  
  RESULTS
  In non-irradiated cells, the venom caused a decrease in cell viability and a massive release of LDH and CK levels indicating myonecrosis. Infrared and red laser at all energy densities were able to considerably decrease venom-induced cytotoxicity. Laser irradiation induced myoblasts to differentiate into myotubes and this effect was accompanied by up regulation of MyoD and specially myogenin. Moreover, LLL was able to reduce the extracellular while increased the intracellular ATP content after venom exposure. In addition, no difference in the intensity of cytotoxicity was shown by non-irradiated and irradiated venom.
  
  
  CONCLUSIONS
  LLL irradiation caused a protective effect on C2C12 cells against the cytotoxicity caused by B. jararacussu venom and promotes differentiation of these cells by up regulation of myogenic factors. A modulatory effect of ATP synthesis may be suggested as a possible mechanism mediating cytoprotection observed under laser irradiation.
authors.affiliation: Posgraduated Program in Medicine, Universidade Nove de Julho-UNINOVE, São Paulo, SP, Brazil.
authors.forename: Luciana Miato Gonçalves
authors.initials: LM
authors.lastname: Silva
authors.affiliation: Posgraduated Program in Medicine, Universidade Nove de Julho-UNINOVE, São Paulo, SP, Brazil.
authors.forename: Camila Aparecida Alves da
authors.initials: CA
authors.lastname: Silva
authors.affiliation: Posgraduated Program in Medicine, Universidade Nove de Julho-UNINOVE, São Paulo, SP, Brazil.
authors.forename: Aline da
authors.initials: Ad
authors.lastname: Silva
authors.affiliation: Posgraduated Program in Medicine, Universidade Nove de Julho-UNINOVE, São Paulo, SP, Brazil.
authors.forename: Rodolfo Paula
authors.initials: RP
authors.lastname: Vieira
authors.affiliation: Posgraduated Program in Biophotonics, Universidade Nove de Julho-UNINOVE, São Paulo, SP, Brazil.
authors.forename: Raquel Agnelli
authors.initials: RA
authors.lastname: Mesquita-Ferrari
authors.affiliation: Institute of Research and Development, Universidade do Vale do Paraíba, UNIVAP, São José dos Campos, SP, Brazil.
authors.forename: José Carlos
authors.initials: JC
authors.lastname: Cogo
authors.affiliation: Posgraduated Program in Medicine, Universidade Nove de Julho-UNINOVE, São Paulo, SP, Brazil.
authors.forename: Stella Regina
authors.initials: SR
authors.lastname: Zamuner
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000528:radiation effects; D015153:Blotting, Western; D017837:Bothrops; D002454:Cell Differentiation / Q000187:drug effects* / Q000528:radiation effects*; D049109:Cell Proliferation / Q000187:drug effects / Q000528:radiation effects; D002478:Cells, Cultured; D007124:Immunoenzyme Techniques; D028022:Low-Level Light Therapy; D051379:Mice; D032446:Myoblasts / Q000187:drug effects / Q000473:pathology* / Q000528:radiation effects; D020011:Protective Agents; D012910:Snake Venoms / Q000633:toxicity*
chemical_list: D020011:Protective Agents; D012910:Snake Venoms; D000255:Adenosine Triphosphate