Author_Institution :
Key Lab. for Space Biosci. & Biotechnol., Northwestern Polytech. Univ., Xi´an, China
Abstract :
The superconducting magnet with a high magnetic force field can levitate diamagnetic materials. In this study, a specially designed superconducting magnet with large gradient high magnetic field (LGHMF), which provides three apparent gravity levels (μg, 1 g, and 2 g), was used to study its influence on receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation from preosteoclast cell line RAW264.7. The effects of LGHMF on the viability, nitric oxide (NO) production, morphology in RAW264.7 cells were detected by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method, the Griess method, and the immunofluorescence staining, respectively. The changes induced by LGHMF in osteoclast formation, mRNA expression, and bone resorption were determined by tartrate-resistant acid phosphatase staining, semiquantity PCR, and bone resorption test, respectively. The results showed that: 1) LGHMF had no lethal effect on osteoclast precursors but attenuated NO release in RAW264.7 cells. 2) Diamagnetic levitation (μg) enhanced both the formation and bone resorption capacity of osteoclast. Moreover, diamagnetic levitation up-regulated mRNA expression of RANK, Cathepsin K, MMP-9, and NFATc1, while down-regulated RunX2 in comparison with controls. Furthermore, diamagnetic levitation induced obvious morphological alterations in osteoclast, including active cytoplasmic peripheral pseudopodial expansion, formation of pedosome belt, and aggregation of actin ring. 3) Magnetic field produced by LGHMF attenuated osteoclast resorption activity. Collectively, LGHMF with combined effects has multiple effects on osteoclast, which attenuated osteoclast resorption with magnetic field, whereas promoted osteoclast differentiation with diamagnetic levitation. Therefore, these findings indicate that diamagnetic levitation could be used as a novel ground-based microgravity simulator, which facilitates bone cell research of weight- essness condition.
Keywords :
RNA; biomagnetism; bone; cellular biophysics; diamagnetism; magnetic fields; magnetic levitation; superconducting magnets; Cathepsin K; Griess method; LGHMF; MMP-9; NFATc1; RAW264.7 cells; actin ring aggregation; bone resorption test; cytoplasmic peripheral pseudopodial expansion; diamagnetic levitation; ground-based microgravity simulator; immunofluorescence staining; large gradient high magnetic field; mRNA expression; magnetic force field; nitric oxide production; nuclear factor-κB ligand; osteoclast differentiation; osteoclast formation; pedosome belt; preosteoclast cell line; receptor activator; superconducting magnet; tartrate-resistant acid phosphatase staining; Bones; Cells (biology); Immune system; Levitation; Magnetic fields; Production; Superconducting magnets; Bone resorption; Large gradient high magnetic field; bone resorption; diamagnetic levitation; large gradient high magnetic field (LGHMF); nitric oxide; nitric oxide (NO); osteoclast differentiation;
