Synergistic effect of low-intensity pulsed ultrasound on growth factor stimulation of nucleus pulposus cells

✍ Scribed by Akihiko Hiyama; Joji Mochida; Toru Iwashina; Hiroko Omi; Takuya Watanabe; Kenji Serigano; Sadahiro Iwabuchi; Daisuke Sakai

• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 221 KB
• Volume: 25
• Category: Article
• ISSN: 0736-0266
• DOI: 10.1002/jor.20460

✦ Synopsis

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‐β type I receptor gene (TGFβR1). Therefore, the present study was conducted to assess the synergistic effect of LIPUS and TGF‐β 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‐β1 group (Group C), and LIPUS + TGF‐β1 group (Group D). They were evaluated by measuring cell proliferation, PG synthesis, PG content, gene expression of TGFβR1, and TGF‐β1 concentration. There were no significant differences in proliferation during culture. However, PG synthesis and endogenous TGF‐β1 production increased and demonstrated a synergistic effect between LIPUS and TGF‐β. 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. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1574–1581, 2007