VPS4B mutation impairs the osteogenic differentiation of dental follicle cells derived from a patient with dentin dysplasia type I

Abstract

A splicing mutation in VPS4B can cause dentin dysplasia type I (DD-I), a hereditary autosomal-dominant disorder characterized by rootless teeth, the etiology of which is genetically heterogeneous. In our study, dental follicle cells (DFCs) were isolated and cultured from a patient with DD-I and compared with those from an age-matched, healthy control. In a previous study, this DD-I patient was confirmed to have a loss-of-function splicing mutation in VPS4B (IVS7 + 46C > G). The results from this study showed that the isolated DFCs were vimentin-positive and CK14-negative, indicating that the isolated cells were derived from the mesenchyme. DFCs harboring the VPS4B mutation had a significantly higher proliferation rate from day 3 to day 8 than control DFCs, indicating that VPS4B is involved in cell proliferation. The cells were then replenished with osteogenic medium to investigate how the VPS4B mutation affected osteogenic differentiation. Induction of osteogenesis, detected by alizarin red and alkaline phosphatase staining in vitro, was decreased in the DFCs from the DD-I patient compared to the control DFCs. Furthermore, we also found that the VPS4B mutation in the DD-I patient downregulated the expression of osteoblast-related genes, such as ALP, BSP, OCN, RUNX2, and their encoded proteins. These outcomes confirmed that the DD-I-associated VPS4B mutation could decrease the capacity of DFCs to differentiate during the mineralization process and may also impair physiological root formation and bone remodeling. This might provide valuable insights and implications for exploring the pathological mechanisms underlying DD-I root development.

Identifying molecular subgroups of patients with preeclampsia through bioinformatics

“…Vacuolar protein sorting 4B (VPS4B) is a member of the ATPase protein family and a crucial component of the sorting complex that regulates membrane protein internalization and lysosomal degradation ( 29 ). VPS4B is closely related to dentin dysplasia pathogenesis ( 30 , 31 ). VPS4B can participate in cell proliferation and act as a regulator of Wnt-β-catenin signaling in human gingival fibroblasts.…”

Abnormal dental follicle cells: A crucial determinant in tooth eruption disorders (Review)

“…Therefore, VPS4B mutations may lead to abnormal osteogenesis by affecting the normal differentiation and proliferation of DFCs, and eventually leading to abnormal tooth eruption. Ultimately, a comparative analysis of the proliferation and osteogenic induction capacity of DFCs derived from patients with VPS4B-mutant DD1 and healthy controls was conducted ( 145 ). The growth rates of DFCs were found to be significantly greater in patients with DD1 than in controls; however, compared with those from control individuals, DFCs from patients with DD1 exhibited lower expression levels of osteogenic genes, such as ALP, OCN, BSP and RUNX2, as well as fewer calcium nodules, as observed via Alizarin red S and ALP staining.…”

Adding Some “Splice” to Stress Eating: Autophagy, ESCRT and Alternative Splicing Orchestrate the Cellular Stress Response

“…A proposed mechanism for how mis-splicing of VPS4B manifests into DDI relates to osteogenic differentiation [142]. The mis-splicing mutation was examined in vitro using dental follicle cells that were isolated and cultured from a patient with DDI.…”