title: Do laser and led phototherapies influence mast cells and myofibroblasts to produce collagen?
abstract: Laser and LED phototherapies accelerate tissue repair. Mast cells induce the proliferation of fibroblasts and the development of local fibrosis. Increased numbers of myofibroblasts and mast cells are frequently found together in a normal wound repair, suggesting that mediators produced by the mast cells could play a role in the regulation of myofibroblast differentiation and function. The aim of this study was to analyze the involvement of mast cells on the synthesis of collagen and their influence on myofibroblast differentiation in the late phase of tissue repair on wounds treated with LLLT (λ 660 nm, 10 J/cm(2), 40 mW, 252 s) or LED (λ 630 ± 10 nm, 10 J/cm(2), 115 mW, 87 s). A 1 × 1-cm surgical wound was created on the dorsum of 30 rats divided into three groups of ten animals each: control, laser, and LED. The animals of each group were irradiated and sacrificed 7 and 14 days after injury. The statistical analysis was performed using the Mann-Whitney and Spearman correlation tests. Laser light improved the collagen deposition rate along the time points (p = 0.22), but when compared to the control groups during the periods studied, the number of mast cells decreased significantly (p ≤ 0.05). With respect to myofibroblasts, the results showed a trend to their reduction. No statistical significances were observed for LED light according to the parameters used in this study. It is concluded that the mast cell and myofibroblast population might participate in the collagen formation of irradiated wounds particularly in relation to laser phototherapy.
authors.affiliation: Center of Biophotonics, School of Dentistry, Federal University of Bahia, Av. Araújo Pinho, 62, Canela, Salvador, Bahia, CEP 40110-150, Brazil, isabeledecastro@gmail.com.
authors.forename: Isabele Cardoso Vieira
authors.initials: IC
authors.lastname: De Castro
authors.forename: Clarissa Araújo Gurgel
authors.initials: CA
authors.lastname: Rocha
authors.forename: Aguida Cristina
authors.initials: AC
authors.lastname: Gomes Henriques
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Cavalcanti de Sousa
authors.forename: Márcio Vieira
authors.initials: MV
authors.lastname: Lisboa
authors.forename: Drielli da Rocha
authors.initials: Dda R
authors.lastname: Sotero
authors.forename: Antônio Luiz Barbosa
authors.initials: AL
authors.lastname: Pinheiro
authors.forename: Patrícia Ramos
authors.initials: PR
authors.lastname: Cury
authors.forename: Jean Nunes Dos
authors.initials: JN
authors.lastname: Santos
mesh_terms: D000818:Animals; D003094:Collagen / Q000096:biosynthesis*; D054023:Lasers, Semiconductor; D028022:Low-Level Light Therapy; D008297:Male; D008407:Mast Cells / Q000378:metabolism* / Q000528:radiation effects; D058628:Myofibroblasts / Q000378:metabolism* / Q000528:radiation effects; D051381:Rats; D017208:Rats, Wistar; D014945:Wound Healing
chemical_list: D003094:Collagen