Molecular evaluation of the BMP2/DLX3 induced osteogenic differentiation in dental follicle cells (DFCs)

BMP2/DLX3 诱导牙囊细胞 (DFC) 成骨分化的分子评估

• 批准号: 319390412
• 负责人: Professor Dr. Christian Morsczeck
• 金额: --
• 依托单位: Klinik und Poliklinik für Mund-, Kiefer- und Gesichtschirurgie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/319390412?language=en
• 关键词: Molecular; evaluation; BMP2; DLX3; induced

Precursor cells of the human dental follicle (DFCs) are the precursors of the periodontium and have the endogenous potential to differentiate into cementoblasts, alveolar osteoblasts and fibroblasts of the periodontal ligament. Due to their high differentiation capability, DFCs provide the promising potential for use in regenerative therapies of craniofacial bone tissue and probably also for the treatment of peripheral bone diseases. However, the molecular mechanisms of differentiation into (alveolar) osteoblasts are still inadequately examined despite much progress during the last years, and need to be further understood before. It was already shown that the initiation of osteogenic differentiation in DFCs is mainly controlled by BMP2 and its induction of the transcription factor DLX3, which leads to the expression of further differentiation markers. Besides, activation of protein kinase A is involved via the phosphorylation und therefore stabilization of β-Catenin, which is the key protein of the canonical WNT signaling pathway. Expression of DLX3 is enhanced after binding of β-Catenin to the TCF/LEF promotor. In contrast, the non-canonical WNT signaling pathway via WNT5A mostly affects proliferation and viability of DFCs and does only indirectly influence differentiation. Furthermore, previous results of the project showed that later differentiation phases until mineralization mainly depend on the regulation of protein kinase C (PKC) and protein kinase B (also called AKT). In addition, both kinases as well as WNT5A and DLX3 affect viability of DFCs. Further preliminary studies showed that increased oxidative stress and a decreased expression of the hypoxia-induced protein HIF-1α are observed during differentiation as well as a significantly increased expression of mitochondrial markers during middle and late periods of differentiation. The preliminary results lead to the new working hypothesis that oxidative stress increases during osteogenic differentiation of DFCs which needs to be neutralized by OSD (oxidative stress defense) proteins – the expression of which might be regulated e.g. via PKC or Akt – in order to facilitate successful osteogenic differentiation. The oxidative stress could originate mainly from increased oxidative phosphorylation in the mitochondria, which enables the energy consuming processes of matrix secretion and mineralization. Hence, the first part of the project is intended to investigate the role of oxidative stress, viability and energy metabolism during osteogenic differentiation, while the second part aims to evaluate the involvement of PKC and Akt. The results of this project will further extend the molecular knowledge about DFCs and contribute to create a fundament for the use of the cells in regenerative therapies of (craniofacial) bone tissue.

人牙囊前体细胞（Precursor cells of the human dental follicle，DFC）是牙周组织的前体细胞，具有向成牙骨质细胞、牙槽骨细胞和牙周膜成纤维细胞分化的内源性潜能。由于其高分化能力，DFC提供了用于颅面骨组织的再生疗法的有希望的潜力，并且可能还用于治疗外周骨疾病。然而，尽管在过去的几年里取得了很大的进展，但分化为（肺泡）成骨细胞的分子机制仍然没有得到充分的研究，需要进一步了解之前。已经表明，DFC中成骨分化的起始主要受BMP 2及其对转录因子DLX 3的诱导控制，这导致进一步分化标志物的表达。此外，蛋白激酶A的激活通过磷酸化参与，从而稳定β-连环蛋白，其是经典WNT信号通路的关键蛋白。β-连环蛋白与TCF/LEF启动子结合后DLX 3的表达增强。相反，通过WNT 5A的非经典WNT信号传导途径主要影响DFC的增殖和活力，并且仅间接影响分化。此外，该项目的先前结果表明，后期分化阶段直到矿化主要取决于蛋白激酶C（PKC）和蛋白激酶B（也称为AKT）的调节。此外，两种激酶以及WNT 5A和DLX 3影响DFC的活力。进一步的初步研究表明，在分化过程中观察到氧化应激增加和缺氧诱导蛋白HIF-1α表达减少，以及在分化中期和晚期线粒体标记物的表达显著增加。初步结果导致了新的工作假设，即在DFC的成骨分化期间氧化应激增加，其需要被OSD（氧化应激防御）蛋白中和-其表达可能例如通过PKC或Akt调节-以促进成功的成骨分化。氧化应激可能主要来源于线粒体中氧化磷酸化的增加，这使得基质分泌和矿化的能量消耗过程成为可能。因此，该项目的第一部分旨在研究成骨分化过程中氧化应激，活力和能量代谢的作用，而第二部分旨在评估PKC和Akt的参与。本项目的研究结果将进一步扩展有关DFCs的分子知识，并为DFCs在（颅面）骨组织再生治疗中的应用奠定基础。