Influence of Low-Intensity Pulsed Ultrasound Stimulation on Expression of Bone-Related Genes in Rat Bone Marrow Cells

Abstract

Low-intensity pulsed ultrasound (LIPUS) is used in physiotherapy and bone fracture healing. Previously we demonstrated that LIPUS enhances bone formation around dental implants inserted into rabbit femur. Here, we present the effect of LIPUS treatment on cell proliferation, alkaline phosphatase (ALPase) activity, and the expression of bone-related genes in bone marrow cells. Cell proliferation was not affected by LIPUS treatment. ALPase activity was increased on day 6 after LIPUS treatment in cells treated with 40 mW/cm 2 ultrasound. Evaluation of gene expression in rat bone marrow cells treated with 40 mW/cm 2 ultrasound demonstrated a shift in the expression of genes associated with bone formation; Cox-2 gene expression was increased 30 min after 5-or 20-min LIPUS treatment. BMP-2 gene expression increased 30 min after 5-min LIPUS treatment or 6 h after 10-min LIPUS treatment. Cbfa1/Runx2 gene expression increased 30 min after 20-min LIPUS treatment. These results suggest that the clinical application of LIPUS for dental implants may promote osseointegration through the activation of bone-related genes.

Effect of Low Intensity Pulsed Ultrasound (LIPUS) on Tooth Movement and Root Resorption: A Prospective Multi-Center Randomized Controlled Trial

“…This leads to increased gene expression [47,48], which in turn leads to increased protein expression [49]. LIPUS increases RANK-L (receptor activator of nuclear factor kappa-ligand) protein expression in the osteoclasts to accelerate bone resorption [50,51], while in osteoblasts LIPUS increases bone-forming proteins RUNX2 (runt-related transcription factor 2) [52], OPG (osteoprotegerin) [53], and ALP (alkaline phosphatase) [54].…”

A Comparison of 1‐ and 3.2‐MHz Low‐Intensity Pulsed Ultrasound on Osteogenesis on Porous Titanium Alloy Scaffolds: An In Vitro and In Vivo Study

“…Numerous reports suggest that LIPUS does not affect cell proliferation . Akagi et al reported no influence of LIPUS on cell proliferation in rat bone marrow cells.…”

“…Numerous reports suggest that LIPUS does not affect cell proliferation . Akagi et al reported no influence of LIPUS on cell proliferation in rat bone marrow cells. Veronick et al demonstrated that LIPUS had no effect on MC3T3 mouse osteoblast cell proliferation on hydrogels.…”

Low-Intensity Pulsed Ultrasound Accelerates Differentiation of Osteoblastic Cells on Roughened Titanium Surface

“…In this study, the cell number on days 5 and 7 did not show any statistical difference between the LIPUS and control groups. Akagi et al also reported that LIPUS had no effect on cell proliferation 34) . In contrast, LIPUS was shown to have a positive effect in the proliferation of osteoblastic cells 39,40) .…”

“…In the orthopedic field, LIPUS has been used to accelerate the process of bone fractures healing [9][10][11] . Although, the biological processes involved in accelerating the repair of the bone fracture when treated with LIPUS are not still fully understood 30) , it was reported that the production of cyclooxygenese 2 (COX-2) in cells was enhanced; this in turn stimulated molecules for enhanced fracture repair 31) through not only increasing the levels of osteogenic molecules, such as bone morphogenetic proteins (BMPs) [32][33][34] , insulin-like growth factor 1 (IGF-1) 35) , stromal cell-derived factor 1 (SDF-1) 36) , and Prostaglandin E2 (PGE2) 37) , but also through promoting the apoptosis of osteoclasts 38) .…”