Zun Yang1, Leixi Ren, Feng Deng, Zhibiao Wang, Jinlin Song. 1. Affiliated Hospital of Stomatology, Chongqing Medical University, 426 Songshi North St, Yubei District, 401147 Chongqing, China. soongjl@163.com.
Abstract
OBJECTIVES: Low-intensity pulsed ultrasound (US) can accelerate fracture healing and osteogenic differentiation. The aim of this study was to investigate the osteogenic effect of low-intensity pulsed US on human periodontal ligament cells and to determine whether bone morphogenetic protein (BMP)-Smad signaling was involved. METHODS: Human periodontal ligament cells were exposed to low-intensity pulsed US at a frequency of 1.5 MHz and intensity of 90 mW/cm(2) for 20 min/d. Osteogenic differentiation was determined by assaying alkaline phosphatase (ALP) and calcium deposition. Expression of BMP-2, BMP-6, and BMP-9 was detected by real-time polymerase chain reaction analysis. Phosphorylated Smad was detected by western blotting; Smad in the cells was labeled by an immunofluorescent antibody and observed by laser-scanning confocal microscopy. RESULTS: The optical density of ALP stimulated by US at 1.5 MHz and 90 mW/cm(2) for 20 min/d was significantly higher than in other groups (P < .01); therefore, this dosage was considered optimal for promoting osteogenic differentiation. After 13 days of US exposure, ALP increased gradually after 5 days, peaked at 11 days, and decreased at 13 days, with a significant difference compared with the control group (P < .05). Osteocalcin production increased from 9 to 13 days and peaked at 15 days, with a significant difference compared with the control group (P < .05). BMP-2 and BMP-6 increased dynamically after exposure for 13 days. BMP-2 increased 6.07-fold at 3 days, 6.39-fold at 11 days, and 5.97-fold at 13 days. BMP-6 expression increased 6.82-fold at 1 day and 51.5-fold at 3 days and decreased thereafter. BMP-9 was not expressed. Phospho-Smad1/5/8 expression was significantly increased after exposure (P< .05) and transferred from the cytoplasm into the nuclei. CONCLUSIONS: Low-intensity pulsed US effectively induced osteogenic differentiation of human periodontal ligament cells, and the BMP-Smad signaling pathway was involved in the mechanism.
OBJECTIVES: Low-intensity pulsed ultrasound (US) can accelerate fracture healing and osteogenic differentiation. The aim of this study was to investigate the osteogenic effect of low-intensity pulsed US on human periodontal ligament cells and to determine whether bone morphogenetic protein (BMP)-Smad signaling was involved. METHODS:Human periodontal ligament cells were exposed to low-intensity pulsed US at a frequency of 1.5 MHz and intensity of 90 mW/cm(2) for 20 min/d. Osteogenic differentiation was determined by assaying alkaline phosphatase (ALP) and calcium deposition. Expression of BMP-2, BMP-6, and BMP-9 was detected by real-time polymerase chain reaction analysis. Phosphorylated Smad was detected by western blotting; Smad in the cells was labeled by an immunofluorescent antibody and observed by laser-scanning confocal microscopy. RESULTS: The optical density of ALP stimulated by US at 1.5 MHz and 90 mW/cm(2) for 20 min/d was significantly higher than in other groups (P < .01); therefore, this dosage was considered optimal for promoting osteogenic differentiation. After 13 days of US exposure, ALP increased gradually after 5 days, peaked at 11 days, and decreased at 13 days, with a significant difference compared with the control group (P < .05). Osteocalcin production increased from 9 to 13 days and peaked at 15 days, with a significant difference compared with the control group (P < .05). BMP-2 and BMP-6 increased dynamically after exposure for 13 days. BMP-2 increased 6.07-fold at 3 days, 6.39-fold at 11 days, and 5.97-fold at 13 days. BMP-6 expression increased 6.82-fold at 1 day and 51.5-fold at 3 days and decreased thereafter. BMP-9 was not expressed. Phospho-Smad1/5/8 expression was significantly increased after exposure (P< .05) and transferred from the cytoplasm into the nuclei. CONCLUSIONS: Low-intensity pulsed US effectively induced osteogenic differentiation of human periodontal ligament cells, and the BMP-Smad signaling pathway was involved in the mechanism.
Entities:
Keywords:
Smad; basic science; bone morphogenetic protein; human periodontal ligament cells; low-intensity pulsed ultrasound; osteogenic differentiation; signal transduction
Authors: Tarek El-Bialy; Khaled Farouk; Terry D Carlyle; William Wiltshire; Robert Drummond; Tim Dumore; Kevin Knowlton; Bryan Tompson Journal: J Clin Med Date: 2020-03-16 Impact factor: 4.241