Epigenetic landscape during osteoblastogenesis defines a differentiation-dependent Runx2 promoter region
Department of Cell and Developmental Biology
Runx2 is a developmentally regulated gene in vertebrates and is essential for bone formation and skeletal homeostasis. The induction of runx2-P1 isoform transcripts is a hallmark of early osteoblastogenesis. Although previous in vitro studies have defined a minimal Runx2-P1 promoter sequence with well-characterized functional elements, several lines of evidence suggest that transcription of the Runx2-P1 isoform relies on elements that extend beyond the previously defined P1 promoter boundaries. In this study, we examined Runx2-P1 transcriptional regulation in a cellular in vivo context during early osteoblastogenesis of MC3T3-E1 cultures and BMSCs induced towards the bone lineage by multi-layered analysis of the Runx2-P1 gene promoter using the following methodologies: 1) sequence homology among several mammalian species, 2) DNaseI hypersensitivity coupled with massively parallel sequencing (DNase-seq), and 3) chromatin immunoprecipitation of activating histone modifications coupled with massively parallel sequencing (ChIP-seq). These epigenetic features have allowed the demarcation of boundaries that redefine the minimal Runx2-P1 promoter to include a 336-bp sequence that mediates responsiveness to osteoblast differentiation. We also find that an additional level of control is contributed by a regulatory region in the 5'-UTR of Runx2-P1.
DNase hypersensitivity, Gene regulation, Histone modification, Osteoblast differentiation, Runx2-P1
DOI of Published Version
Gene. 2014 Oct 15;550(1):1-9. doi: 10.1016/j.gene.2014.05.044. Epub 2014 Jun 2. Link to article on publisher's site
Tai, Phillip W. L.; Wu, Hai; Gordon, Jonathan A.R.; Whitfield, Troy W.; Barutcu, Ahmet Rasim; Van Wijnen, Andre J.; Lian, Jane B.; Stein, Gary S.; and Stein, Janet L., "Epigenetic landscape during osteoblastogenesis defines a differentiation-dependent Runx2 promoter region" (2014). GSBS Student Publications. 2008.