Long noncoding RNAs (lncRNAs) are emerging as important regulators in molecular processes and may play vital roles in odontogenic differentiation of human dental pulp stem cells (hDPSCs). However, their functions remain to be elucidated. As lncRNA H19 is one of the most classical lncRNA, which plays essential roles in cellular differentiation, thus we explored the effects and mechanisms of H19 in odontogenic differentiation of hDPSCs. Stable overexpression and knockdown of H19 in hDPSCs were constructed using recombinant lentiviruses containing H19 and short hairpin-H19 expression cassettes, respectively. Alkaline phosphatase (ALP) assay, Alizarin red staining assay, von kossa staining, quantitative polymerase chain reaction (qPCR), Western blot analysis, and immunofluorescent staining results indicated that overexpression of H19 in hDPSCs positively regulates the odontogenic differentiation of hDPSCs, while knockdown of H19 in hDPSCs inhibits odontogenic differentiation of hDPSCs. Further, we found that H19 promotes the odontogenic differentiation of hDPSCs through S-adenosylhomocysteine hydrolase (SAHH) epigenetically regulates the methylation and expression of distal-less homeobox (DLX3) gene. Herein, for the first time, we determined that H19/SAHH axis epigentically regulates odontogenic differentiaiton of hDPSCs by inhibiting the DNA methyltransferase 3B (DNMT3B)-mediated methylation of DLX3. Our findings provide a new insight into how H19/SAHH axis play its role in odontogenic differentiation of hDPSCs, and would be helpful in developing therapeutic approaches for dentin regeneration based on stem cells.

长非编码RNA（lncRNA）逐渐成为分子过程中的重要调节剂，并且可能在人类牙髓干细胞（hDPSC）的牙源性分化中发挥重要作用。但是，它们的功能仍有待阐明。lncRNA H19是最经典的lncRNA之一，在细胞分化中起着至关重要的作用，因此我们探讨了H19在hDPSCs牙源性分化中的作用和机制。使用分别包含H19和短发夹-H19表达盒的重组慢病毒构建hDPSC中H19的稳定过表达和敲低。碱性磷酸酶（ALP）测定，茜素红染色测定，冯·科萨（von kossa）染色，定量聚合酶链反应（qPCR），蛋白质印迹分析，免疫荧光染色结果表明，hDPSCs中H19的过表达正调控hDPSCs的牙源性分化，而敲除hDPSCs中的H19则抑制hDPSCs的牙源性分化。此外，我们发现H19通过S-腺苷同型半胱氨酸水解酶（SAHH）促进hDPSCs的牙源性分化，表观遗传上调控远侧同源盒（DLX3）基因的甲基化和表达。在这里，我们第一次确定H19 / SAHH轴通过抑制DLX3的DNA甲基转移酶3B（DNMT3B）介导的甲基化来调控hDPSC的牙源性分化。我们的发现为H19 / SAHH轴如何在hDPSC的牙源性分化中发挥作用提供了新的见解，