Primary cilia respond to intermittent low-magnitude, high-frequency vibration and mediate vibration-induced effects in osteoblasts.
Our objective was to investigate the role of primary cilia in low-magnitude, high-frequency vibration (LMHFV) treatment of MC3T3-E1 osteoblasts (OBs). We used chloral hydrate (CH), which has a well-characterized function in chemically removing primary cilia, to elucidate the role of primary cilia in LMHFV-induced OB osteogenic responses through cell viability assay, Western blot analysis, real-time quantitative RT-PCR, and histochemical staining methods. We observed a significant, 30% decrease in the number of MC3T3-E1 OBs with primary cilia (reduced from 64.3 ± 5%) and an approximately 50% reduction in length of primary cilia (reduced from 3 ± 0.8 μm) after LMHFV stimulation. LMHFV stimulation upregulated protein expression of the bone matrix markers collagen 1 (COL-1), osteopontin (OPN), and osteoclacin(OCN) in MC3T3-E1 OBs, indicating that LMHFV induces osteogenesis. High-concentration or long-duration CH exposure resulted in inhibition of MC3T3-E1 OB survival. In addition, Western blot analysis and RT-PCR revealed that CH treatment prevented LMHFV-induced osteogenesis. Furthermore, decreased alkaline phosphate activity, reduced OB differentiation, mineralization, and maturation were observed in CH-pretreated and LMHFV-treated OBs. We showed that LMHFV induces morphological changes in primary cilia that may fine-tune their mechanosensitivity. In addition, we demonstrated the significant inhibition by CH of LMHFV-induced OB mineralization, maturation, and differentiation, which might reveal the critical role of primary cilia in the process.
['Li|Yan-Hui|YH|', 'Zhu|Dong|D|', 'Cao|Zongbing|Z|', 'Liu|Yanwei|Y|', 'Sun|Jian|J|', 'Tan|Lei|L|']
D016475:3T3 Cells D000818:Animals D002454:Cell Differentiation D002697:Chloral Hydrate D002923:Cilia D024042:Collagen Type I D050659:Core Binding Factor Alpha 1 Subunit D051546:Cyclooxygenase 2 D005786:Gene Expression Regulation D040542:Mechanotransduction, Cellular D051379:Mice D010006:Osteoblasts D015675:Osteocalcin D010012:Osteogenesis D053495:Osteopontin D013997:Time Factors D014732:Vibration
primary cilia high-frequency vibration osteoblasts chloral hydrate differentiation low-magnitude, mineralization