Lijun Sun1, Shuxin Sun2, Xinjuan Zhao1, Jing Zhang1, Jianzhong Guo3, Liang Tang4, Dean Ta5,6,7. 1. Institute of Sports Biology, Shaanxi Normal University, Xi'an, 710119, China. 2. Department of Electronic Engineering, Fudan University, Shanghai, 200433, China. 3. Shaanxi Key Laboratory of Ultrasonics, Shaanxi Normal University, Xi'an, 710119, China. 4. Institute of Sports Biology, Shaanxi Normal University, Xi'an, 710119, China. tl531@snnu.edu.cn. 5. Department of Electronic Engineering, Fudan University, Shanghai, 200433, China. tda@fudan.edu.cn. 6. Human Phenome Institute, Fudan University, Shanghai, 201203, China. tda@fudan.edu.cn. 7. Key Laboratory of Medical Imaging Computing and Computer Assisted Intervention (MICCAI) of Shanghai, Shanghai, 200032, China. tda@fudan.edu.cn.
Abstract
PURPOSE: Low-intensity pulsed ultrasound (LIPUS) is effective in promoting bone healing, and a myostatin deficiency also has a positive effect on bone formation. In this study, we evaluated the effects of LIPUS on bone healing in rats in vivo and investigated the mechanisms in vitro, aiming to explore whether LIPUS promotes bone healing through inhibition of the myostatin signaling pathway. METHODS: Rats with both drill-hole defects and MC3T3-E1 cells were randomly assigned to a LIPUS group and a control group. The LIPUS group received LIPUS treatment (1.5 MHz, 30 mW/cm2) for 20 min/day. RESULTS: After 21 days, the myostatin expression in quadriceps was significantly inhibited in the LIPUS group, and remodeling of the newly formed bone in the drill-hole site was significantly better in the LIPUS group than that in the control group, which was confirmed by micro-CT analysis. After 3 days, LIPUS significantly promoted osteoblast proliferation; inhibited the expression of AcvrIIB (the myostatin receptor), Smad3, p-Smad3, and GSK-3β; and increased Wnt1 and β-catenin expression. Moreover, translocation of β-catenin from the cytolemma to the nucleus was observed in the LIPUS group. However, these effects were blocked by treatment with myostatin recombinant protein. CONCLUSIONS: The results indicate that LIPUS may promote bone healing through inhibition of the myostatin signal pathway.
PURPOSE: Low-intensity pulsed ultrasound (LIPUS) is effective in promoting bone healing, and a myostatin deficiency also has a positive effect on bone formation. In this study, we evaluated the effects of LIPUS on bone healing in rats in vivo and investigated the mechanisms in vitro, aiming to explore whether LIPUS promotes bone healing through inhibition of the myostatin signaling pathway. METHODS:Rats with both drill-hole defects and MC3T3-E1 cells were randomly assigned to a LIPUS group and a control group. The LIPUS group received LIPUS treatment (1.5 MHz, 30 mW/cm2) for 20 min/day. RESULTS: After 21 days, the myostatin expression in quadriceps was significantly inhibited in the LIPUS group, and remodeling of the newly formed bone in the drill-hole site was significantly better in the LIPUS group than that in the control group, which was confirmed by micro-CT analysis. After 3 days, LIPUS significantly promoted osteoblast proliferation; inhibited the expression of AcvrIIB (the myostatin receptor), Smad3, p-Smad3, and GSK-3β; and increased Wnt1 and β-catenin expression. Moreover, translocation of β-catenin from the cytolemma to the nucleus was observed in the LIPUS group. However, these effects were blocked by treatment with myostatin recombinant protein. CONCLUSIONS: The results indicate that LIPUS may promote bone healing through inhibition of the myostatin signal pathway.
Entities:
Keywords:
Bone healing; Bone micro-architectures; Low-intensity pulsed ultrasound; Myostatin; Proliferation; Wnt
Authors: T Noda; H Nagano; I Takemasa; S Yoshioka; M Murakami; H Wada; S Kobayashi; S Marubashi; Y Takeda; K Dono; K Umeshita; N Matsuura; K Matsubara; Y Doki; M Mori; M Monden Journal: Br J Cancer Date: 2009-04-28 Impact factor: 7.640