Pulsed electromagnetic fields simultaneously induce osteogenesis and upregulate transcription of bone morphogenetic proteins 2 and 4 in rat osteoblasts in vitro.
Pulsed electromagnetic fields (PEMF) are successfully employed in the treatment of a variety of orthopaedic conditions, particularly delayed and nonunion fractures. In this study, we examined PEMF effects on in vitro osteogenesis by bone nodule formation and on mRNA expression of bone morphogenetic proteins 2 and 4 by reverse-transcriptase polymerase chain reaction (RT-PCR) in cultured rat calvarial osteoblasts. PEMF exposure induced a significant increase in both the number (39% over unexposed controls) and size (70% larger compared to unexposed controls) of bone-like nodules formed. PEMF also induced an increase in the levels of BMP-2 and BMP-4 mRNA in comparison to controls. This effect was directly related to the duration of PEMF exposure. This study shows that clinically applied PEMF have a reproducible osteogenic effect in vitro and simultaneously induce BMP-2 and -4 mRNA transcription. This supports the concept that the two effects are related.
Bodamyali
T
T
School of Postgraduate Medicine, University of Bath, Claverton Down, United Kingdom.
Bhatt
B
B
Hughes
F J
FJ
Winrow
V R
VR
Kanczler
J M
JM
Simon
B
B
Abbott
J
J
Blake
D R
DR
Stevens
C R
CR
D000818:Animals; D055396:Bone Morphogenetic Protein 2; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins / Q000096:biosynthesis / Q000235:genetics*; D002454:Cell Differentiation / Q000528:radiation effects; D004574:Electromagnetic Fields; D009024:Morphogenesis / Q000528:radiation effects; D010006:Osteoblasts / Q000166:cytology / Q000502:physiology / Q000528:radiation effects; D051381:Rats; D012886:Skull; D015533:Transcriptional Activation / Q000528:radiation effects*; D016212:Transforming Growth Factor beta
C525720:Bmp2 protein, rat; C525811:Bmp4 protein, rat; D055396:Bone Morphogenetic Protein 2; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins; D016212:Transforming Growth Factor beta