Department of Prosthodontics and Periodontics, Piracicaba Dental School, University of Campinas, Piracicaba, Brazil.
Health Science Institute, School of Dentistry, Paulista University-UNIP, São Paulo, Brazil.
DNA Cell Biol. 2021 May;40(5):662-674. doi: 10.1089/dna.2020.6239. Epub 2021 Mar 22.
Periodontal ligament cells (PDLCs) have well documented osteogenic potential; however, this commitment can be highly heterogenous, limiting their applications in tissue regeneration. In this study, we use PDLC populations characterized by high and low osteogenic potential (h-PDLCs and l-PDLCs, respectively) to identify possible sources of such heterogeneity and to investigate whether the osteogenic differentiation can be enhanced by epigenetic modulation. In h-PDLCs, low basal expression levels of pluripotency markers (, ), DNA methyltransferases (, ), and enzymes involved in active DNA demethylation (, ) were prerequisite to high osteogenic potential. Furthermore, these genes were downregulated upon early osteogenesis, possibly allowing for the increase in expression of the key osteogenic transcription factors, Runt-related transcription factor 2 () and , and ultimately, mineral nodule formation. l-PDLCs appeared locked in the multipotent state and this was further enhanced upon early osteogenic stimulation, correlating with low expression and impaired mineralization. Further upregulation of s was also evident, while pretreatment with RG108, the DNMTs' inhibitor, enhanced the osteogenic program in l-PDLCs through downregulation of s, increased RUNX2 expression and nuclear localization, accelerated expression of osteogenic markers, and increased mineralization. These findings point toward the role of DNMTs and Ten Eleven Translocations (TETs) in osteogenic commitment and support application of epigenetic approaches to modulate biomineralization in PDLCs.
牙周膜细胞 (PDLCs) 具有明确的成骨潜力；然而，这种潜能具有高度异质性，限制了它们在组织再生中的应用。在这项研究中，我们使用具有高和成骨潜力的 PDLC 群体（分别为 h-PDLCs 和 l-PDLCs）来鉴定这种异质性的可能来源，并研究成骨分化是否可以通过表观遗传调控来增强。在 h-PDLCs 中，多能性标志物（、）、DNA 甲基转移酶（、）和参与活性 DNA 去甲基化的酶（、）的低基础表达水平是高成骨潜力的前提。此外，这些基因在早期成骨过程中下调，可能允许关键成骨转录因子 Runt 相关转录因子 2 () 和 的表达增加，最终导致矿化结节形成。l-PDLCs 似乎被锁定在多能状态，并且在早期成骨刺激下进一步增强，这与低表达和矿化受损相关。s 的进一步上调也很明显，而在用 RG108（DNMTs 的抑制剂）预处理后，通过下调 s、增加 RUNX2 表达和核定位、加速成骨标志物的表达和增加矿化，增强了 l-PDLCs 的成骨程序。这些发现表明 DNMTs 和 Ten Eleven Translocations (TETs) 在成骨潜能中的作用，并支持应用表观遗传方法来调节 PDLCs 中的生物矿化。
