title: Effects of low level laser therapy on inflammatory and angiogenic gene expression during the process of bone healing: A microarray analysis.
abstract: The process of bone healing as well as the expression of inflammatory and angiogenic genes after low level laser therapy (LLLT) were investigated in an experimental model of bone defects. Sixty Wistar rats were distributed into control group and laser group (830nm, 30mW, 2,8J, 94seg). Histopathological analysis showed that LLLT was able to modulate the inflammatory process in the area of the bone defect and also to produce an earlier deposition of granulation tissue and newly formed bone tissue. Microarray analysis demonstrated that LLLT produced an up-regulation of the genes related to the inflammatory process (MMD, PTGIR, PTGS2, Ptger2, IL1, 1IL6, IL8, IL18) and the angiogenic genes (FGF14, FGF2, ANGPT2, ANGPT4 and PDGFD) at 36h and 3days, followed by the decrease of the gene expression on day 7. Immunohistochemical analysis revealed that the subjects that were treated presented a higher expression of COX-2 at 36h after surgery and an increased VEGF expression on days 3 and 7 after surgery. Our findings indicate that LLLT was efficient on accelerating the development of newly formed bone probably by modulating the inflammatory and angiogenic gene expression as well as COX2 and VEGF immunoexpression during the initial phase of bone healing.
authors.affiliation: Federal University of São Carlos, Department of Physiotherapy, Rod Washington Luis Km 235, São Carlos 13565-905, Brazil. Electronic address: carlinha_tim@hotmail.com.
authors.forename: Carla Roberta
authors.initials: CR
authors.lastname: Tim
authors.affiliation: Federal University of São Paulo, Department of Bioscience, Av. Ana Costa 95, Santos 11050-240, Brazil.
authors.forename: Paulo Sérgio
authors.initials: PS
authors.lastname: Bossini
authors.affiliation: Federal University of São Carlos, Department of Physiotherapy, Rod Washington Luis Km 235, São Carlos 13565-905, Brazil.
authors.forename: Hueliton Wilian
authors.initials: HW
authors.lastname: Kido
authors.affiliation: Federal University of São Carlos, Department of Genetics and Evolution, Rod Washington Luis Km 235, São Carlos 13565-905, Brazil.
authors.forename: Iran
authors.initials: I
authors.lastname: Malavazi
authors.affiliation: University of São Paulo, School of Pharmaceutical Sciences of Ribeirão Preto, Department of Clinical Analysis, Toxicological and Bromatological, Av. do Café 95, Ribeirão Preto, Brazil, 14049-900, Brazil.
authors.forename: Marcia Regina
authors.initials: MR
authors.lastname: von Zeska Kress
authors.affiliation: State University of Campinas, Department of Genetics and Evolution, 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: Federal University of São Carlos, Department of Physiotherapy, Rod Washington Luis Km 235, São Carlos 13565-905, Brazil.
authors.forename: Nivaldo Antonio
authors.initials: NA
authors.lastname: Parizotto
authors.affiliation: Federal University of São Paulo, Department of Bioscience, Av. Ana Costa 95, Santos 11050-240, Brazil.
authors.forename: Ana Cláudia
authors.initials: AC
authors.lastname: Rennó
mesh_terms: D000818:Animals; D001847:Bone Diseases / Q000378:metabolism / Q000473:pathology / Q000532:radiotherapy*; D001861:Bone Regeneration / Q000528:radiation effects; D001842:Bone and Bones / Q000378:metabolism / Q000473:pathology; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects*; D028022:Low-Level Light Therapy; D008297:Male; D046228:Microarray Analysis; D051381:Rats; D017208:Rats, Wistar; D044006:Receptors, Epoprostenol; D011982:Receptors, Prostaglandin / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation / Q000528:radiation effects; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism
chemical_list: D016207:Cytokines; C491909:Ptgir protein, rat; D044006:Receptors, Epoprostenol; D011982:Receptors, Prostaglandin; D042461:Vascular Endothelial Growth Factor A; D051546:Cyclooxygenase 2
keywords: Bone repair; Gene expression; LLLT; Microarray