Accelerated tooth movement in Rsk2-deficient mice with impaired cementum formation

Abstract

Coffin–Lowry–Syndrome (CLS) is a X-linked mental retardation characterized by skeletal dysplasia and premature tooth loss. We and others have previously demonstrated that the ribosomal S6 kinase RSK2, mutated in CLS, is essential for bone and cementum formation; however, it remains to be established whether RSK2 plays also a role in mechanically induced bone remodeling during orthodontic tooth movement (OTM). We, therefore, performed OTM in wild-type (WT) mice and Rsk2-deficient mice using Nitinol tension springs that were fixed between the upper left molars and the incisors. The untreated contralateral molars served as internal controls. After 12 days of OTM, the jaws were removed and examined by micro-computed tomography (µCT), decalcified histology, and immunohistochemistry. Our analysis of the untreated teeth confirmed that the periodontal phenotype of Rsk2-deficient mice is characterized by alveolar bone loss and hypoplasia of root cementum. Quantification of OTM using µCT revealed that OTM was more than two-fold faster in Rsk2-deficient mice as compared to WT. We also observed that OTM caused alveolar bone loss and root resorptions in WT and Rsk2-deficient mice. However, quantification of these orthodontic side effects revealed no differences between WT and Rsk2-deficient mice. Taken together, Rsk2 loss-of-function accelerates OTM in mice without causing more side effects.

Novel one-pot strategy for fabrication of a pH-Responsive bone-targeted drug self-frame delivery system for treatment of osteoporosis

“…Among these genes, DC-STAMP, a dendritic cell-specific transmembrane protein, a seven-fold transmembrane protein that is directly involved in the regulation of cell-to-cell fusion, and it is also commonly used as a marker of osteoclast fusion [ 68 ]. c-Fos and NFATc1 are the key nuclear transcription factors in osteoclast differentiation [ 69 , 70 ]. The heterodimer transcription factor AP-1 consists of c-Fos/c-Jun increased NFATc1 expression and transcriptional activity [ 71 ].…”

Zebrafish as a Model to Unveil the Pro-Osteogenic Effects of Boron-Vitamin D3 Synergism

“…RSK2 (encoded by rps6ka3a gene) was shown to be highly upregulated in the B10VD group relative to B100VD and VD groups, which is particularly relevant, given its importance for osteoblast differentiation and function (60). It is in fact involved at the distal end of the MAPK pathway, where it plays a key role in bone turnover by phosphorylating different substrates, such as cAMP response element-binding protein, which is a known inducer of osteoblast differentiation and c-Fos, which is an osteoclast differentiation inducer (61)(62)(63). C-Fos was found to be downregulated in both VD and B10VD, but osteoclast marker gene ctsk was upregulated only in VD.…”

Force-induced Caspase-1-dependent pyroptosis regulates orthodontic tooth movement

“…In mice, nickel-titanium coil springs with the same size and 1 mm in length were ligated in a similar way to provide 20–30 g force for 7 d. 12 , 28 , 29 The contralateral first molar served as control. Mice were randomly divided into four groups as follows: (i) Force: force loading and 0.9% NaCl treatment every two days; (ii) Force + PPVI: force loading and pyroptosis activator Polyphyllin VI (PPVI, S9302, Selleck) treatment (5 mg/kg every two days); (iii) Force + MCC950: force loading and pyroptosis inhibitor MCC950 (S7809, Selleck) treatment (20 mg/kg every two days); (iv) Control: the group without force loading and treatment.…”