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Therapeutic ultrasound stimulates MC3T3‐E1 cell proliferation through the activation of NF‐κB1, p38α, and mTOR
Author(s) -
Tassinary João A.F.,
Lunardelli Adroaldo,
Basso Bruno S.,
Stülp Simone,
Pozzobon Adriane,
Pedrazza Leonardo,
Bartrons Ramon,
Ventura Francesc,
Rosa Jose L.,
Melo Denizar A.S.,
Nunes Fernanda B.,
Donadio Márcio V.F.,
Oliveira Jarbas R.
Publication year - 2015
Publication title -
lasers in surgery and medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 112
eISSN - 1096-9101
pISSN - 0196-8092
DOI - 10.1002/lsm.22414
Subject(s) - pi3k/akt/mtor pathway , osteoblast , osteopontin , calcium in biology , chemistry , microbiology and biotechnology , cell growth , calcium , intracellular , medicine , signal transduction , in vitro , biology , biochemistry
Background and Objectives As the population ages, osteometabolic diseases and osteoporotic fractures emerge, resulting in substantial healthcare resource utilization and impaired quality of life. Many types of mechanical stimulation have the potential of being recognized by bone cells after a mechanical sign is transformed into a biological one (a process called mechanotransduction). The therapeutic ultrasound (TU) is one of several resources capable of promoting bone cell mechanical stimulation. Therefore, the main purpose of present study was to evaluate the effect of TU on the proliferation of pre‐osteoblasts using in vitro bioassays. Study Design/Materials and Methods We used MC3T3‐E1 pre‐osteoblast lineage cells kept in Alpha medium. Cells were treated using pulsed mode therapeutic ultrasound, with frequency of 1 MHz, intensity of 0.2 W/cm 2 (SATA), duty cycle of 20%, for 30 minutes. Nifedipine and rapamycin were used to further investigate the role of L‐type Ca 2+ channels and mTOR pathway. Intracellular calcium, TGF‐β1, magnesium, and the mRNA levels of osteopontin, osteonectin, NF‐κB1, p38α were evaluated. Results The results show that TU stimulates the growth of MC3T3‐E1 cells and decreases the supernatant calcium and magnesium content. Also, it increases intracellular calcium, activates NF‐κB1 and mTOR complex via p38α. Moreover, TU promoted a decrease in the TGF‐β1 synthesis, which is a cell growth inhibitor. Conclusions Therapeutic ultrasound, with frequency of 1 MHz, intensity of 0.2 W/cm 2 (SATA) and pulsed mode, for 30 minutes, was able to increase the proliferation of preosteoblast‐like bone cells. This effect was mediated by a calcium influx, with a consequent activation of the mTOR pathway, through increased NF‐κB1 and p38α. Lasers Surg. Med. 47:765–772, 2015. © 2015 Wiley Periodicals, Inc.