Low-intensity pulsed ultrasound produced an increase of osteogenic genes expression during the process of bone healing in rats.
The aim of this study was to measure the temporal expression of osteogenic genes during the process of bone healing in low-intensity pulsed ultrasound (LIPUS) treated bone defects by means of histopathologic and real-time polymerase chain reaction (PCR) analysis. Animals were randomly distributed into two groups (n = 30): control group (bone defect without treatment) and LIPUS treated (bone defect treated with LIPUS). On days 7, 13 and 25 postinjury, 10 rats per group were sacrificed. Rats were treated with a 30 mW/cm(2) LIPUS. The results pointed out intense new bone formation surrounded by highly vascularized connective tissue presenting a slight osteogenic activity, with primary bone deposition was observed in the group exposed to LIPUS in the intermediary (13 days) and late stages of repair (25 days) in the treated animals. In addition, quantitative real-time polymerase chain reaction (RT-qPCR) showed an upregulation of bone morphogenetic protein 4 (BMP4), osteocalcin and Runx2 genes 7 days after the surgery. In the intermediary period, there was no increase in the expression. The expression of alkaline phosphatase, BMP4 and Runx2 was significantly increased at the last period. Our results indicate that LIPUS therapy improves bone repair in rats and upregulated osteogenic genes, mainly at the late stages of recovery.
Department of Physiotherapy, Federal University of São Carlos, São Carlos, São Paulo, Brazil.
Elaine
E
Fávaro-Pípi
Paulo
P
Bossini
Poliani
P
de Oliveira
Juliana Uema
JU
Ribeiro
Carla
C
Tim
Nivaldo A
NA
Parizotto
Jose Marcos
JM
Alves
Daniel Araki
DA
Ribeiro
Heloísa Sobreiro
HS
Selistre de Araújo
Ana Claudia Muniz
AC
Renno
D000469:Alkaline Phosphatase / Q000235:genetics / Q000378:metabolism; D000818:Animals; D055415:Bone Morphogenetic Protein 4 / Q000378:metabolism*; D050659:Core Binding Factor Alpha 1 Subunit / Q000235:genetics / Q000378:metabolism; D017102:Fracture Healing / Q000235:genetics* / Q000502:physiology; D015870:Gene Expression; D008297:Male; D015675:Osteocalcin / Q000235:genetics / Q000378:metabolism; D010012:Osteogenesis / Q000235:genetics*; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012269:Ribosomal Proteins / Q000235:genetics; D013977:Tibia / Q000378:metabolism / Q000473:pathology; D013978:Tibial Fractures / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D014464:Ultrasonic Therapy; D015854:Up-Regulation
D055415:Bone Morphogenetic Protein 4; D050659:Core Binding Factor Alpha 1 Subunit; D012269:Ribosomal Proteins; C041184:ribosomal protein S18; D015675:Osteocalcin; D000469:Alkaline Phosphatase