Different Methylation Patterns of RUNX2, OSX, DLX5 and BSP in Osteoblastic Differentiation of Mesenchymal Stem Cells

Objective: runt-related transcription factor 2 (runx2) and osterix (osx) as two specificosteoblast transcription factors and distal-less homeobox 5 (dlx5) as a non-specific oneare of paramount importance in regulating osteoblast related genes including osteocalcin,bone sialoprotein (bsp), osteopontin and collagen type i?1. the present study sets out toinvestigate whether epigenetic regulation of these genes is important in osteoblastic differentiationof mesenchymal stem cells (mscs).materials and methods: in this experimental study, mscs were differentiated to osteoblastsunder the influence of the osteogenic differentiation medium. dna and rna wereextracted at days 0, 7, 14 and 21 from mscs differentiating to osteoblasts. promoterregions of runx2, osx, dlx5 and bsp were analyzed by methylation-specific pcr(msp). gene expression was analyzed during osteoblastic differentiation by quantitativereal-time polymerase chain reaction (pcr).results: msp analysis revealed that promoter methylation status did not change inrunx2, dlx5 and bsp during msc osteoblastic differentiation. in contrast, osx promotershowed a dynamic change in methylation pattern. moreover, runx2, osx, dlx5and bsp promoter regions showed three different methylation patterns during msc differentiation.gene expression analyses confirmed these results.conclusion: the results show that in differentiation of mscs to osteoblasts, epigeneticregulation of osx may play a leading role.