Effects of low-level laser therapy on expression of TNF-α and TGF-β in skeletal muscle during the repair process.
The aim of the present study was to determine the effect of low-level laser therapy (LLLT) on the expression of TNF-α and TGF-β in the tibialis anterior muscle of rats following cryoinjury. Muscle regeneration involves cell proliferation, migration and differentiation and is regulated by growth factors and cytokines. A growing body of evidence suggests that LLLT promotes skeletal muscle regeneration by reducing the duration of acute inflammation and accelerating tissue repair. Adult male Wistar rats (n = 35) were randomly divided into three groups: control group (no lesion, untreated, n = 5), cryoinjury without LLLT group (n = 15), and cryoinjury with LLLT group (n = 15). The injured region was irradiated three times a week using an AlGaInP laser (660 nm; beam spot 0.04 cm(2), output power 20 mW, power density 500 mW/cm(2), energy density 5 J/cm(2), exposure time 10 s). Muscle remodeling was evaluated at 1, 7 and 14 days (long-term) following injury. The muscles were removed and total RNA was isolated using TRIzol reagent and cDNA synthesis. Real-time polymerase chain reactions were performed using TNF-α and TGF-β primers; GAPDH was used to normalize the data. LLLT caused a decrease in TNF-α mRNA expression at 1 and 7 days following injury and in TGF-β mRNA expression at 7 days following cryoinjury in comparison to the control group. LLLT modulated cytokine expression during short-term muscle remodeling, inducing a decrease in TNF-α and TGF-β.
Departamento de Pós Graduação, Mestrado em Ciências da Reabilitação, Universidade Nove de Julho - UNINOVE, Av. Francisco Matarazzo, 612, Água Branca, CEP 05001-100, São Paulo, SP, Brazil. raquel.mesquita@gmail.com
Raquel Agnelli
RA
Mesquita-Ferrari
Manoela Domingues
MD
Martins
Jose Antônio
JA
Silva
Tatiana Dias
TD
da Silva
Roberto Farina
RF
Piovesan
Vanessa Christina Santos
VC
Pavesi
Sandra Kalil
SK
Bussadori
Kristianne Porta Santos
KP
Fernandes
D000818:Animals; D001483:Base Sequence; D015870:Gene Expression / Q000528:radiation effects; D028022:Low-Level Light Therapy; D008297:Male; D018482:Muscle, Skeletal / Q000293:injuries / Q000502:physiology* / Q000528:radiation effects*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012038:Regeneration / Q000235:genetics / Q000502:physiology / Q000528:radiation effects; D016212:Transforming Growth Factor beta / Q000235:genetics*; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*; D014945:Wound Healing / Q000235:genetics / Q000502:physiology / Q000528:radiation effects
D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D014409:Tumor Necrosis Factor-alpha