title: Effects of low-level laser therapy on the expression of osteogenic genes during the initial stages of bone healing in rats: a microarray analysis.
abstract: This study evaluated the morphological changes produced by LLLT on the initial stages of bone healing and also studied the pathways that stimulate the expression of genes related to bone cell proliferation and differentiation. One hundred Wistar rats were divided into control and treated groups. Noncritical size bone defects were surgically created at the upper third of the tibia. Laser irradiation (Ga-Al-As laser 830 nm, 30 mW, 94 s, 2.8 J) was performed for 1, 2, 3, 5, and 7 sessions. Histopathology revealed that treated animals produced increased amount of newly formed bone at the site of the injury. Moreover, microarray analysis evidenced that LLLT produced a significant increase in the expression TGF-β, BMP, FGF, and RUNX-2 that could stimulate osteoblast proliferation and differentiation, which may be related to improving the deposition of newly formed bone at the site of the injury. Thus, it is possible to conclude that LLLT improves bone healing by producing a significant increase in the expression of osteogenic genes.
authors.affiliation: Department of Physiotherapy, Federal University of São Carlos, Rod Washington Luis Km 235, São Carlos, 13565-905, Brazil. carlinha_tim@hotmail.com.
authors.forename: Carla Roberta
authors.initials: CR
authors.lastname: Tim
authors.affiliation: Department of Bioscience, Federal University of São Paulo, Av. Ana Costa 95, Santos, 11050-240, Brazil.
authors.forename: Paulo Sérgio
authors.initials: PS
authors.lastname: Bossini
authors.affiliation: Department of Physiotherapy, Federal University of São Carlos, Rod Washington Luis Km 235, São Carlos, 13565-905, Brazil.
authors.forename: Hueliton Wilian
authors.initials: HW
authors.lastname: Kido
authors.affiliation: Department of Genetics and Evolution, Federal University of São Carlos, Rod Washington Luis Km 235, São Carlos, 13565-905, Brazil.
authors.forename: Iran
authors.initials: I
authors.lastname: Malavazi
authors.affiliation: Department of Clinical Analysis, Toxicological and Bromatological, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Av. do Café 95, Ribeirão Preto, 14049-900, Brazil.
authors.forename: Marcia Regina
authors.initials: MR
authors.lastname: von Zeska Kress
authors.affiliation: Department of Genetics and Evolution, State University of Campinas, Cidade Universitária Zeferino Vaz, Campinas, 13083-970, Brazil.|Brazilian National Center for Research in Energy and Materials, Brazilian Biosciences National Laboratory, Giuseppe Máximo Scolfaro 10.000, Campinas, 13083-970, Brazil.
authors.forename: Marcelo Falsarella
authors.initials: MF
authors.lastname: Carazzolle
authors.affiliation: Department of Physiotherapy, Federal University of São Carlos, Rod Washington Luis Km 235, São Carlos, 13565-905, Brazil.
authors.forename: Nivaldo Antonio
authors.initials: NA
authors.lastname: Parizotto
authors.affiliation: Department of Bioscience, Federal University of São Paulo, Av. Ana Costa 95, Santos, 11050-240, Brazil.
authors.forename: Ana Cláudia
authors.initials: AC
authors.lastname: Rennó
mesh_terms: D000818:Animals; D001861:Bone Regeneration / Q000235:genetics / Q000528:radiation effects; D028022:Low-Level Light Therapy; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis; D010012:Osteogenesis / Q000235:genetics* / Q000528:radiation effects*; D051381:Rats; D017208:Rats, Wistar; D013977:Tibia / Q000502:physiology* / Q000528:radiation effects*; D014945:Wound Healing / Q000235:genetics / Q000528:radiation effects*
keywords: Bone regeneration; LLLT; Microarray; Osteogenic genes