title: Low level laser therapy modulates viability, alkaline phosphatase and matrix metalloproteinase-2 activities of osteoblasts.
abstract: Low level laser therapy (LLLT) has been shown to stimulate bone cell metabolism but their impact on the matrix metalloproteinase (MMP) expression and activity is little explored. This study evaluated the influence of LLLT at two different wavelengths, red and infrared, on MC3T3-E1 preosteoblast viability, alkaline phosphatase (ALP) and MMP-2 and -9 activities. To accomplish this, MC3T3-E1 cells were irradiated with a punctual application of either red (660nm; InGaAIP active medium) or infrared (780nm; GaAlAs active medium) lasers both at a potency of 20mW, energy dose of 0.08 or 0.16J, and energy density of 1.9J/cm2or 3.8J/cm2, respectively. The control group received no irradiation. Cellular viability, ALP and MMP-2 and -9 activities were assessed by MTT assay, enzymatic activity and zymography, respectively, at 24, 48 and 72h. The treatment of cells with both red and infrared lasers significantly increased the cellular viability compared to the non-irradiated control group at 24 and 48h. The ALP activity was also up modulated in infrared groups at 24 and 72h, depending on the energy densities. In addition, the irradiation with red laser at the energy density of 1.9J/cm2promoted an enhancement of MMP-2 activity at 48 and 72h. However, no differences were observed for the MMP-9 activity. In conclusion, when used at these specific parameters, LLL modulates both preosteoblast viability and differentiation highlighted by the increased ALP and MMP-2 activities induced by irradiation.
authors.affiliation: Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil.
authors.forename: Flávia Amadeu de
authors.initials: FA
authors.lastname: Oliveira
authors.affiliation: Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil.
authors.forename: Adriana Arruda
authors.initials: AA
authors.lastname: Matos
authors.affiliation: Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil.
authors.forename: Sandra Satiko
authors.initials: SS
authors.lastname: Matsuda
authors.affiliation: Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil.
authors.forename: Marília Afonso Rabelo
authors.initials: MA
authors.lastname: Buzalaf
authors.affiliation: Departamento de Física e Ciência dos Materiais, Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, SP, Brazil.
authors.forename: Vanderley Salvador
authors.initials: VS
authors.lastname: Bagnato
authors.affiliation: Department of Pediatric Dentistry, Orthodontics and Public Health, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil.
authors.forename: Maria Aparecida de Andrade Moreira
authors.initials: MA
authors.lastname: Machado
authors.affiliation: Department of Prosthodontics/Periodontics, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil.
authors.forename: Carla Andreotti
authors.initials: CA
authors.lastname: Damante
authors.affiliation: Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil. Electronic address: rodrigocardoso@usp.br.
authors.forename: Rodrigo Cardoso de
authors.initials: RC
authors.lastname: Oliveira
authors.affiliation: Universidade do Sagrado Coração, Pró-Reitoria de Pesquisa e Pós-Graduação, Bauru, SP, Brazil.
authors.forename: Camila
authors.initials: C
authors.lastname: Peres-Buzalaf
mesh_terms: D016475:3T3 Cells; D000469:Alkaline Phosphatase / Q000528:radiation effects; D000818:Animals; D002454:Cell Differentiation / Q000528:radiation effects; D002470:Cell Survival / Q000528:radiation effects; D006801:Humans; D007259:Infrared Rays; D007834:Lasers; D008027:Light; D028022:Low-Level Light Therapy; D020778:Matrix Metalloproteinase 2 / Q000528:radiation effects; D020780:Matrix Metalloproteinase 9 / Q000528:radiation effects; D051379:Mice; D010006:Osteoblasts / Q000166:cytology* / Q000201:enzymology
chemical_list: D000469:Alkaline Phosphatase; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9
keywords: ALP; LLL; Laser therapy; MMP-2; MMP-9; Preosteoblast