MiR⁃31 Promotes the Proliferation and Migration of Human Dental Pulp Mesenchymal Stem Cells / 中国生物化学与分子生物学报

ABSTRACT

Pulpitis and periapical inflammation are two common diseases in stomatology today. Existing treatment options primarily include root canal therapy and pulp revascularization, which can effectively control inflammation and preserve the affected tooth while also causing permanent deactivation of the pulp tissue, structural failure, and secondary infection. In recent years, research on dental pulp regeneration has progressively entered the public consciousness because of tissue engineering technology that combines stem cells and biomaterials. Due to their multi⁃differentiation and high proliferation, dental pulp stem cells (DPSCs) isolated from permanent or deciduous teeth have emerged as a significant stem cell source for dentin or pulp tissue regeneration. However, the number and survival time of live cells in the dam⁃ aged area are impacted, which significantly limits the efficacy of stem cells since they are unable to efficiently be recruited to the injured area. The ability of DPSCs to migrate and multiply must therefore be enhanced. This study sought to determine if miR⁃31 (miR⁃31) may significantly enhance the proliferative and migratory capacities of DPSCs. The tissue block enzyme digestion method was used to successfully separate and culture DPSCs from dental pulp tissues, and the miR⁃31 levels in dental pulp tissues and DPSCs from normal and inflammatory teeth were compared. The results of real⁃time fluorescence quanti⁃ tative PCR (RT⁃qPCR) revealed that the expression level of miR⁃31 in dental pulp tissues and DPSCs from inflammatory teeth was significantly lower when compared to the control group (P<0. 05). Interfer⁃ ence and over⁃expression of miR⁃31 expressions in DPSCs were specifically divided into three groups the NC group, the miR⁃31 agomir (over⁃expressed) group and the miR⁃31 antagomir (inhibitor) group. RTq⁃PCR results showed that the transfection was successful (P<0. 001). The results of CCK⁃8, wound⁃ healing, and Transwell migration experiments showed that overexpression of miR⁃31 successfully improved the proliferation and migration abilities of DPSCs compared with the control group (P<0. 05). Further⁃ more, Western blotting analysis revealed that miR⁃31 overexpression increased the expression of important migratory proteins, including CXC chemokine receptor type 4 (CXCR4) and matrix metalloproteinase2 (MMP2), as well as key proliferation proteins Ki67 and proliferating cell nuclear antigen (PCNA) (P< 0. 05). This study demonstrates that miR⁃31 can effectively boost the proliferation and migratory ability of DPSCs, providing strong theoretical support for the increased use of DPSCs in regenerative medicine.