title: Synergistic effect of low-intensity pulsed ultrasound on growth factor stimulation of nucleus pulposus cells.
abstract: Low-intensity pulsed ultrasound (LIPUS) has been reported to stimulate the activity of various cells. We have reported that the capacity of human intervertebral nucleus pulposus cell line to synthesize proteoglycan (PG) was increased by exposure to LIPUS, and postulated that one of the mechanisms underlying this response was an increase in expression of the transforming growth factor-beta type I receptor gene (TGFbetaR1). Therefore, the present study was conducted to assess the synergistic effect of LIPUS and TGF-beta on nucleus pulposus cells harvested from canines. The cells were cultured under four different sets of conditions: control group (Group A), LIPUS group (Group B), TGF-beta1 group (Group C), and LIPUS + TGF-beta1 group (Group D). They were evaluated by measuring cell proliferation, PG synthesis, PG content, gene expression of TGFbetaR1, and TGF-beta1 concentration. There were no significant differences in proliferation during culture. However, PG synthesis and endogenous TGF-beta1 production increased and demonstrated a synergistic effect between LIPUS and TGF-beta. Because LIPUS is safe and noninvasive, the results of the present study suggest that it would be a promising new therapy for prevention of intervertebral disc degeneration, which is said to be one of the primary causes of low back pain.
authors.affiliation: Department of Orthopaedic Surgery, Surgical Science, Tokai University School of Medcine, Boseidai, Isehara, Kanagawa 259-1193, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Hiyama
authors.forename: Joji
authors.initials: J
authors.lastname: Mochida
authors.forename: Toru
authors.initials: T
authors.lastname: Iwashina
authors.forename: Hiroko
authors.initials: H
authors.lastname: Omi
authors.forename: Takuya
authors.initials: T
authors.lastname: Watanabe
authors.forename: Kenji
authors.initials: K
authors.lastname: Serigano
authors.forename: Sadahiro
authors.initials: S
authors.lastname: Iwabuchi
authors.forename: Daisuke
authors.initials: D
authors.lastname: Sakai
mesh_terms: D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D004285:Dogs; D005260:Female; D007403:Intervertebral Disc / Q000000981:diagnostic imaging* / Q000187:drug effects / Q000378:metabolism; D016014:Linear Models; D011509:Proteoglycans / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D053773:Transforming Growth Factor beta1 / Q000378:metabolism / Q000494:pharmacology*; D014464:Ultrasonic Therapy; D014463:Ultrasonography
chemical_list: D011509:Proteoglycans; D053773:Transforming Growth Factor beta1