title: Low-level laser irradiation promotes the proliferation and maturation of keratinocytes during epithelial wound repair.
abstract: Low-level laser therapy (LLLT) has been extensively employed to improve epithelial wound healing, though the exact response of epithelium maturation and stratification after LLLT is unknown. Thus, this study aimed to assess the in vitro growth and differentiation of keratinocytes (KCs) and in vivo wound healing response when treated with LLLT. Human KCs (HaCaT cells) showed an enhanced proliferation with all the employed laser energy densities (3, 6 and 12 J/cm(2) , 660 nm, 100 mW), together with an increased expression of Cyclin D1. Moreover, the immunoexpression of proteins related to epithelial proliferation and maturation (p63, CK10, CK14) all indicated a faster maturation of the migrating KCs in the LLLT-treated wounds. In that way, an improved epithelial healing was promoted by LLLT with the employed parameters; this improvement was confirmed by changes in the expression of several proteins related to epithelial proliferation and maturation. Immunofluorescent expression of cytokeratin 10 (red) and Cyclin D1 (green) in (A) Control keratinocytes and (B) Low-level laser irradiated cells. Blue color illustrates the nuclei of the cells (DAPI staining).
authors.affiliation: Department of Pathology and Parasitology, Institute of Biomedical Sciences, Federal University of Alfenas, Alfenas, 37130-000, MG, Brazil. sperandio@usp.br, felipe.fornias@unifal-mg.edu.br.|Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA 02114, USA. sperandio@usp.br, felipe.fornias@unifal-mg.edu.br.|Department of Dermatology, Harvard Medical School, Boston, MA 02115, USA. sperandio@usp.br, felipe.fornias@unifal-mg.edu.br.
authors.forename: Felipe F
authors.initials: FF
authors.lastname: Sperandio
authors.affiliation: Department of Biomaterials and Oral Biology, School of Dentistry, University of São Paulo, São Paulo, 05508-000, SP, Brazil.
authors.forename: Alyne
authors.initials: A
authors.lastname: Simões
authors.affiliation: Department of Oral Pathology, School of Dentistry, University of São Paulo, São Paulo, 05508-000, SP, Brazil.
authors.forename: Luciana
authors.initials: L
authors.lastname: Corrêa
authors.affiliation: Department of Restorative Dentistry, Special Laboratory of Lasers in Dentistry (LELO), School of Dentistry, University of São Paulo, São Paulo, 05508-000, SP, Brazil.
authors.forename: Ana Cecília C
authors.initials: AC
authors.lastname: Aranha
authors.affiliation: A. C. Camargo Cancer Center, National Institute of Oncogenomics and National Institute of Translational Neurosciences, São Paulo, 01508010, SP, Brazil.
authors.forename: Fernanda S
authors.initials: FS
authors.lastname: Giudice
authors.affiliation: Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA 02114, USA.|Department of Dermatology, Harvard Medical School, Boston, MA 02115, USA.|Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA 02139, USA.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Hamblin
authors.affiliation: Department of Oral Pathology, School of Dentistry, University of São Paulo, São Paulo, 05508-000, SP, Brazil.
authors.forename: Suzana C O M
authors.initials: SC
authors.lastname: Sousa
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000528:radiation effects; D002460:Cell Line; D002465:Cell Movement / Q000528:radiation effects; D049109:Cell Proliferation / Q000528:radiation effects; D004848:Epithelium / Q000528:radiation effects; D005260:Female; D006801:Humans; D015603:Keratinocytes / Q000166:cytology* / Q000378:metabolism / Q000528:radiation effects*; D007633:Keratins / Q000378:metabolism; D028022:Low-Level Light Therapy; D051381:Rats; D017208:Rats, Wistar; D014945:Wound Healing / Q000528:radiation effects*
chemical_list: D007633:Keratins
keywords: Cyclin D1; HaCaT keratinocytes; keratins; low-level laser therapy; p63 protein; photobiomodulation; wound healing