Bernhard-Heine-Center for Locomotion Research, University of Würzburg, Würzburg, Germany; Department of Conservative Dentistry, School of Dental Medicine, University Hospital Tübingen, Tübingen, Germany.
Bernhard-Heine-Center for Locomotion Research, University of Würzburg, Würzburg, Germany; IZKF Research Group Tissue Regeneration in Musculoskeletal Diseases, University Hospital Würzburg, Würzburg, Germany.
Exp Cell Res. 2020 Jul 15;392(2):112026. doi: 10.1016/j.yexcr.2020.112026. Epub 2020 Apr 22.
Mineralization disorders with a broad range of etiological factors represent a huge challenge in dental diagnosis and therapy. Hypophosphatasia (HPP) belongs to the rare diseases affecting predominantly mineralized tissues, bones and teeth, and occurs due to mutations in the ALPL gene, which encodes tissue-nonspecific alkaline phosphatase (TNAP). Here we analyzed stem cells from bone marrow (BMSCs), dental pulp (DPSCs) and periodontal ligament (PDLSCs) in the absence and presence of efficient TNAP inhibitors. The differentiation capacity, expression of surface markers, and gene expression patterns of donor-matched dental cells were compared during this in vitro study. Differentiation assays showed efficient osteogenic but low adipogenic differentiation (aD) capacity of PDLSCs and DPSCs. TNAP inhibitor treatment completely abolished the mineralization process during osteogenic differentiation (oD). RNA-seq analysis in PDLSCs, comparing oD with and without TNAP inhibitor levamisole, showed clustered regulation of candidate molecular mechanisms that putatively impaired osteogenesis and mineralization, disequilibrated ECM production and turnover, and propagated inflammation. Combined alteration of cementum formation, mineralization, and elastic attachment of teeth to cementum via elastic fibers may explain dental key problems in HPP. Using this in vitro model of TNAP deficiency in DPSCs and PDLSCs, we provide novel putative target areas for research on molecular cues for specific dental problems in HPP.
具有广泛病因因素的矿化障碍在牙科诊断和治疗中是一个巨大的挑战。低磷酸酯酶症（HPP）属于主要影响矿化组织、骨骼和牙齿的罕见疾病，是由于编码组织非特异性碱性磷酸酶（TNAP）的 ALPL 基因突变引起的。在这里，我们分析了骨髓（BMSCs）、牙髓（DPSCs）和牙周膜（PDLSCs）干细胞在缺乏和存在有效 TNAP 抑制剂的情况下的情况。在这项体外研究中，比较了供体匹配的牙齿细胞的分化能力、表面标志物表达和基因表达模式。分化实验表明，PDLSCs 和 DPSCs 具有有效的成骨但低脂肪分化（aD）能力。TNAP 抑制剂处理完全抑制了成骨分化（oD）过程中的矿化。在 PDLSCs 中，将 oD 与 TNAP 抑制剂左旋咪唑进行比较的 RNA-seq 分析表明，候选分子机制的聚类调节可能损害了成骨和矿化、细胞外基质（ECM）产生和周转失衡，并引发了炎症。通过弹性纤维联合改变牙骨质的形成、矿化和牙齿与牙骨质的弹性附着，可能解释了 HPP 中牙齿的主要问题。使用 DPSCs 和 PDLSCs 中 TNAP 缺乏的这种体外模型，我们为 HPP 中特定牙齿问题的分子线索研究提供了新的潜在靶区。
