DNMT1 mediated methylation silences miR-214-3p gene and promotes hair follicle stem cell differentiate into adipogenic lineages

Abstract

Background Dysfunction of the DNA methylation was associated with stem cell reprogramming. Moreover, DNA methyltransferase 1 (DNMT1) deficiency was involved in the differentiation of hair follicle stem cell (HFSc), but the molecular mechanisms remain unknown. Methods HFSc from human scalp tissues were isolated and cultured. The oil red O staining was used to detect the adipogenesis. The interaction relationship between microRNA (miR)-214-3p and mitogen-activated protein kinase 1 (MAPK1) was accessed by dual-luciferase reporter gene assay. The methylation level of miR-214-3p promoter was detected by methylation-specific PCR, and the enrichment of DNMT1 in miR-214-3p promoter was detected by chromatin immunoprecipitation assay (ChIP). The mouse model of trauma was established to observe the skin regeneration at 0, 6 and 14 days. Results Expression of DNMT1 and MAPK1 was increased in the HFSc, while the expression of miR-214-3p was reduced. Moreover, DNMT1 inhibited the expression of miR-214-3p by promoting the promoter methylation of miR-214-3p. Overexpression of DNMT1 could reduce the expression of miR-214-3p but increased the expression of MAPK1 and the extent of extracellular signal regulated kinase (ERK)1/2 phosphorylation. DNMT1 also significantly enhanced the adipogenic differentiation, and increased the proportion and markers of adipogenic cells. Importantly, DNMT1 promoted skin regeneration in vivo. Conversely, overexpression of miR-214-3p could reverse the effects of DNMT1 on adipogenesis of HFSc. Conclusion DNMT1 promotes adipogenesis of HFSc by mediating miR-214-3p/MAPK1/phosphorylated-ERK1/2 axis. This study may provide more biomarkers for the potential application in stem cell therapy.