Pulsed electromagnetic fields promote osteoblast mineralization and maturation needing the existence of primary cilia

Abstract

Although pulsed electromagnetic fields (PEMFs) have been approved as a therapy for osteoporosis, action mechanisms and optimal parameters are elusive. To determine the optimal intensity, exposure effects of 50 Hz PEMFs of 0.6-3.6 mT (0.6 interval at 90 min/day) were investigated on proliferation and osteogenic differentiation of cultured calvarial osteoblasts. All intensity groups stimulated proliferation significantly with the highest effect at 0.6 mT. The 0.6 mT group also obtained the optimal osteogenic effect as demonstrated by the highest ALP activity, ALP(+) CFU-f colony formation, nodule mineralization, and expression of COL-1 and BMP-2. To verify our hypothesis that the primary cilia are the cellular sensors for PEMFs, osteoblasts were also transfected with IFT88 siRNA or scrambled control, and osteogenesis-promoting effects of 0.6 mT PEMFs were found abrogated when primary cilia were inhibited by IFT88 siRNA. Thus primary cilia of osteoblasts play an indispensable role in mediating PEMF osteogenic effect in vitro.

Mitochondrial ROS Release and Subsequent Akt Activation Potentially Mediated the Anti-Apoptotic Effect of a 50-Hz Magnetic Field on FL Cells

“…MF exposure has been reported to affect cell fate in a bimodal fashion, either cytotoxic or cytoprotective [12,13]. To assess whether MF exposure had any effects on cell death or cell viability, FL cells were exposed to a 50-Hz MF at 0.4 mT for 30, 60, or 120 min, then cell early apoptosis and cell viability were determined by Annexin/PI staining and CCK-8, respectively.…”

Underlying Signaling Pathways and Therapeutic Applications of Pulsed Electromagnetic Fields in Bone Repair

“…Therefore, the improvement of the present available technologies is still needed to acquire more satisfactory clinical outcomes in bone defect repair. PEMFs, as described above, have a marked function to accelerate the proliferation, osteogenic differentiation, and mutation of BMSCs by activating a series of signaling pathways [7, 21, 25, 31, 38, 73]. Moreover, the expressions of many osteogenesis- and angiogenesis-promoting cytokines, including TGF-β, BMPs, IGFs, FGFs, and VEGFs, in BMSCs are strikingly elevated by PEMF exposure.…”

“…Therefore, effective treatment strategy for promoting bone growth and remodeling is needed. Pulsed electromagnetic fields (PEMFs) have been recently employed as a effective method to enhance bone repair because of their non-invasiveness, safety, lack of side effects, convenience, and superior treatment prospects in several refractory bone diseases, such as non-unions and delayed healings of fractures [3-5], osteoporosis [6, 7] and osteonecrosis of the femoral head (ONFH) [8, 9]. In this review, we analyze and summarize the latest research progress on the underlying signaling pathways of PEMFs-induced bone repair and its therapeutic application.…”

Effects of pyrite bioleaching solution of Acidithiobacillus ferrooxidans on viability, differentiation and mineralization potentials of rat osteoblasts

“…A. f ? N-pyrite solution (100 dilution), estradiol (1.0 9 10 -8 M) or control, the osteoblasts were analyzed by immunofluorescence staining for Runx-2 protein expression (Zhou et al 2011;Yan et al 2015). Briefly, immunofluorescence staining was performed using specific rabbit anti-Runx-2 primary antibodies (1:400) (abcam, Cambridge, MA, USA) and Rhodamine (TRITC)-conjugated Affinipure Goat anti-rabbit IgG (H ?…”