Evaluation molekularer Mechanismen während der osteogenen Differenzierung in Vorläuferzellen des dentalen Follikels (DFV)

• Applicant: Professor Dr. Christian Morsczeck
• Subject Area: Human Genetics
• Term: from 2008 to 2014
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 60331293

Dental follicle progenitor/stem cells (DFCs) could be used for cellular therapies in the future, but little is known about their osteogenic differentiation mechanisms. In the previous work of the funded project it could be shown that the osteogenic differentiation of DFCs can be induced with BMP2 or dexamethasone. EDX analyses have shown that DFCs produce biominerals, which are comparable to those of differentated mesenchymal bone marrow stem cells. Since differentiated DFCs did not express dentinogenic markers, they are also very interesting for research on the mechanisms of cementoblasts or alveolar osteoblasts differentiation. Previous results of this project suggested a BMP-independent pathway for the differentiation of DFCs. In genome-wide expression studies, the transcription factor (TF) ZBTB16 was identified as a starting point for the evaluation of putative BMP-independent mechanisms of differentiation. However, initial studies with ZBTB16 revealed that ZBTB16 induces BMP2 while the TF DLX3 induces ZBTB16. DLX3 was already identified as a putative factor for the osteogenic differentiation of DFCs before the start of this project. Investigations of this project showed that the TF DLX3 supports the osteogenic differentiation of DFCs by a BMP2-feedback control. Based on these results, the project will now focus on factors/pathways that are associated with the BMP2/DLX3 feedback loop. Here, there is evidence that DLX3 regulates the TF EGR1, the NOTCH and WNT signaling pathways, which are also associated with differentiating DFCs. Moreover, extracellular matrix (ECM) proteins also influence the differentiation of DFCs. The renewal proposal will now examine the functional relationship of identified molecular processes during osteogenic differentiation in DFCs. In the first part of the project sub-processes are analyzed, which are associated with the DLX3 supported differentiation. Here, the TF EGR1 or biological processes or molecular functions such as the WNT signaling pathway will be examined for their relation to the TF DLX3 supported osteogenic differentiation of DFCs. In the second part of the project the influence of ECM protein binding integrins and their associated signaling pathways will be investigated. This influence should be evaluated on the level of molecular mechanisms in differentiating DFCs; especially on that of the BMP2/DLX3-pathway. The obtained detailed knowledge about the differentiation will provide new insights into the development of the periodontium and may also improve options for the therapeutic use of DFCs, e.g. procedures of bone-augmentation.

• DFG Programme: Research Grants