Enhancer of zeste homolog 2 enhances the migration and chemotaxis of dental mesenchymal stem cells

DNA Methylation and Histone Modification in Dental-derived Mesenchymal Stem Cells

Epigenetic regulation, mainly involving DNA methylation, histone modification, and noncoding RNAs (ncRNAs), is essential for the regulation of multiple cellular processes. Dental-derived mesenchymal stem cells (DMSCs), a kind of multipotent cells derived from dental tissues, are impactful in regenerative medicine. Recent studies have shown that epigenetic regulation plays a major role in DMSCs. Therefore, exploring how epigenetic regulation is involved in DMSCs may be of guiding significance for tissue repair and regeneration or for exploring more effective treatments. A number of research of ncRNAs in DMSCs have been reported. However, little is known about the roles of DNA methylation and histone modifications in DMSCs. In this review, we summarize the important roles of DNA methylation and histone modifications of the fate of DMSCs.

miR-141-3p Regulates EZH2 to Attenuate Porphyromonas gingivalis Lipopolysaccharide-Caused Inflammation and Inhibition of Osteogenic Differentiation in Human Periodontal Ligament Stem Cells

Objective

miR-141-3p has been demonstrated to be both anti-inflammatory and osteoprotective. This study is aimed at investigating the effect of miR-141-3p on osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs) stimulated by Porphyromonas gingivalis lipopolysaccharide (PgLPS) and its mechanism.

Methods

PgLPS was used to induce an inflammatory environment, and overexpression of miR-141-3p was done to assess its effect on hPDLSCs in an inflammatory environment. The level of miR-141-3p and EZH2 in hPDLSCs from each treatment group was detected via qRT-PCR, and the inflammatory factors IL-6 and IL-8 in the supernatant of each group were detected by ELISA. ALP staining and alizarin red staining were used to assess the effect of miR-141-3p on the osteogenic differentiation ability of hPDLSCs, and also, western blot was used to detect expression of osteogenic differentiation-related proteins. Further, dual-luciferase reporter assay examined whether miR-141-3p targeted EZH2.

Results

PgLPS led to a significant decrease of miR-141-3p in hPDLSCs. Overexpression of miR-141-3p could enhance ALP activity and alizarin red staining intensity and increase Runx2, OPN and OCN protein expression levels in PgLPS-treated hPDLSCs. Additionally, miR-141-3p could reduce IL-6 and IL-8. miR-141-3p could target and negatively regulate EZH2, and overexpression of EZH2 reversed the promoting effect of miR-141-3p on osteogenic differentiation.

Conclusion

miR-141-3p can attenuate PgLPS-induced inhibition of osteogenic differentiation and inflammation in hPDLSCs by negatively regulating EZH2.

Role of enhancer of zeste homolog 2 in osteoclast formation and periodontitis development by downregulating microRNA-101-regulated VCAM-1

The enhancer of zeste homolog 2 (EZH2) represents a potential target for periodontitis treatment; however, its role in the development of periodontitis remains unclear. The current study aimed to elucidate the role of EZH2 in osteoclasts (OCs) growth as well as the mechanism underpinning the related process. The potential interaction among EZH2, microRNA-101 (miR-101), and vascular cell adhesion molecule 1 (VCAM-1) was evaluated using chromatin immunoprecipitation and dual-luciferase reporter gene assay. The expressions of EZH2 and miR-101 in OCs were examined by Western blot analysis and reverse transcription squantitative polymerase chain reaction. Loss- and gain-function assays were then performed to determine the role of EZH2/miR-101/VCAM-1 in periodontitis and OCs proliferation, followed by OC growth and proliferation detected using tartrate resistant acid phosphatase (TRAP) and 5-ethynyl-2'-deoxyuridine staining. Enzyme-linked immunoassay was conducted to determine the expression of interleukin 1β (IL-1β) and tumor necrosis factor-α (TNF-α). A periodontitis rat model was established to investigate the effect of EZH2 and VCAM-1 in vivo. EZH2 was overexpressed, while miR-101 was downregulated in the OCs of periodontitis. Silencing of EZH2, VCAM-1 repression, or miR-101 elevation suppressed the growth and proliferation of OC while acting to encumber the release of IL-1β and TNF-α. EZH2 negatively targeted miR-101, while miR-101 negatively targeted VCAM-1. Moreover, silencing of EZH2 or VCAM-1 was observed to attenuate periodontitis which was evidenced by an increase in BMD, BV/TV, and BS/BV as well as reduction in TRAP and cathepsin K in vivo. Taken together, the key findings of the current study demonstrate that EZH2 knockdown inhibited OC formation by elevating the expression of miR-101 via suppression of VCAM-1, ultimately attenuating periodontitis.