Effects of ultrasound on transforming growth factor-beta genes in bone cells.
Therapeutic ultrasound (US) is a widely used form of biophysical stimulation that is increasingly applied to promote fracture healing. Transforming growth factor-beta (TGF-beta), which is encoded by three related but different genes, is known to play a major part in bone growth and repair. However, the effects of US on the expression of the TGF-beta genes and the physical acoustic mechanisms involved in initiating changes in gene expression in vitro, are not yet known. The present study demonstrates that US had a differential effect on these TGF-beta isoforms in a human osteoblast cell line, with the highest dose eliciting the most pronounced up-regulation of both TGF-beta1 and TGF-beta3 at 1 hour after treatment and thereafter declining. In contrast, US had no effect on TGF-beta2 expression. Fluid streaming rather than thermal effects or cavitation was found to be the most likely explanation for the gene responses observed in vitro.
Harle
J
J
University Department of Radiology, Oxford, UK.
Mayia
F
F
Olsen
I
I
Salih
V
V
D000162:Acoustics; D001842:Bone and Bones / Q000166:cytology*; D045744:Cell Line, Tumor; D005786:Gene Expression Regulation; D006801:Humans; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013696:Temperature; D053773:Transforming Growth Factor beta1 / Q000235:genetics*; D053781:Transforming Growth Factor beta2 / Q000235:genetics*; D053782:Transforming Growth Factor beta3 / Q000235:genetics*; D014465:Ultrasonics
D012333:RNA, Messenger; D053773:Transforming Growth Factor beta1; D053781:Transforming Growth Factor beta2; D053782:Transforming Growth Factor beta3