IADR Abstract Archives
Molecular Mechanism of BAF45A Chromatin Regulation in Odontoblasts
Objectives: Tissue specific epigenetic regulation and the resulting gene expression patterns contribute to cellular identity and function. Remodeling of chromatin by the BAF complex contributes to gene activation by sliding nucleosomes into an open conformation around active loci. Cell specific BAF activity arises from the modular composition of subunits. However, little is known about BAF complex mediated gene expression in dental pulp cells. Our lab has identified BAF45A as an essential BAF subunit for differentiation in osteoblasts. The objective of this study is to characterize the molecular function of BAF45A and its homologs BAF45B/C/D during differentiation of odontoblasts.
Methods: To characterize BAF45A mediated BAF activity in odontoblast, we subjected OD-21 pre-odontoblast cells to differentiation conditions. We analyzed the changes in expression of Baf45 homologs and odontoblast specific genes in undifferentiated and differentiated cells. We also performed ChIP-QPCR and ATAC-seq to assess the changes in BAF complex occupancy and chromatin accessibility at these tissue specific loci.
Results: Here we show that BAF45A and BAF45D are preferentially expressed in odontoblasts compared to BAF45B and BAF45C. BAF45A is part of the Polybromo-BAF (PBAF) complex. Here we show that loss of BAF45A causes a reduction in chromatin accessibility at genes important for mineralization and differentiation. We also assess histone acetylation chromatin occupancy around these genes.
Conclusions:
BAF45A is an important BAF complex member for the development of mineralized tissue, in both bone and tooth. BAF45A, in addition to BAF45D, are the primary homologs expressed in these tissues and it appears at this time that the expression of BAF45B and BAF45C are negligible for differentiation and development.
Methods: To characterize BAF45A mediated BAF activity in odontoblast, we subjected OD-21 pre-odontoblast cells to differentiation conditions. We analyzed the changes in expression of Baf45 homologs and odontoblast specific genes in undifferentiated and differentiated cells. We also performed ChIP-QPCR and ATAC-seq to assess the changes in BAF complex occupancy and chromatin accessibility at these tissue specific loci.
Results: Here we show that BAF45A and BAF45D are preferentially expressed in odontoblasts compared to BAF45B and BAF45C. BAF45A is part of the Polybromo-BAF (PBAF) complex. Here we show that loss of BAF45A causes a reduction in chromatin accessibility at genes important for mineralization and differentiation. We also assess histone acetylation chromatin occupancy around these genes.
Conclusions:
BAF45A is an important BAF complex member for the development of mineralized tissue, in both bone and tooth. BAF45A, in addition to BAF45D, are the primary homologs expressed in these tissues and it appears at this time that the expression of BAF45B and BAF45C are negligible for differentiation and development.