Journal Article

miRNA-720 Controls Stem Cell Phenotype, Proliferation and Differentiation of Human Dental Pulp Cells

Tajima, Shoji, Pham, Hai Thanh, Eguchi, Takanori, Kubota, Satoshi, Kuboki, Takuo, Ono, Mitsuaki, Takigawa, Masaharu, Hara, Emilio Satoshi, Sonoyama, Wataru, Calderwood, Stuart K.

2013

Overview

Dental pulp cells (DPCs) are known to be enriched in stem/progenitor cells but not well characterized yet. Small non-coding microRNAs (miRNAs) have been identified to control protein translation, mRNA stability and transcription, and have been reported to play important roles in stem cell biology, related to cell reprogramming, maintenance of stemness and regulation of cell differentiation. In order to characterize dental pulp stem/progenitor cells and its mechanism of differentiation, we herein sorted stem-cell-enriched side population (SP) cells from human DPCs and periodontal ligament cells (PDLCs), and performed a locked nucleic acid (LNA)-based miRNA array. As a result, miR-720 was highly expressed in the differentiated main population (MP) cells compared to that in SP cells. In silico analysis and a reporter assay showed that miR-720 targets the stem cell marker NANOG, indicating that miR-720 could promote differentiation of dental pulp stem/progenitor cells by repressing NANOG. Indeed, gain-and loss-of-function analyses showed that miR-720 controls NANOG transcript and protein levels. Moreover, transfection of miR-720 significantly decreased the number of cells positive for the early stem cell marker SSEA-4. Concomitantly, mRNA levels of DNA methyltransferases (DNMTs), which are known to play crucial factors during stem cell differentiation, were also increased by miR-720 through unknown mechanism. Finally, miR-720 decreased DPC proliferation as determined by immunocytochemical analysis against ki-67, and promoted odontogenic differentiation as demonstrated by alizarin red staining, as well as alkaline phosphatase and osteopontin mRNA levels. Our findings identify miR-720 as a novel miRNA regulating the differentiation of DPCs.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: 3' Untranslated Regions / Adult / Alizarin / Alkaline phosphatase / Base Pairing / Base Sequence / Biochemistry / Biocompatibility / Biology / Biomarkers / Biomedical materials / Cancer / Cell differentiation / Cell Differentiation - genetics / Cell Line / Cell Proliferation / Cells (biology) / Cellular biology / Cluster Analysis / Control stability / Cytochemistry / Dental pulp / Dental Pulp - cytology / Dental Pulp - physiology / Dentistry / Deoxyribonucleic acid / Differentiation (biology) / DNA / DNA (Cytosine-5-)-Methyltransferases - metabolism / DNA methylation / DNA Methyltransferase 3A / DNA Methyltransferase 3B / Flow Cytometry / Gene Expression Profiling / Gene Expression Regulation / Genetic aspects / Genotype & phenotype / Homeodomain Proteins - genetics / Humans / Medicine / Methyltransferases / MicroRNA / MicroRNAs / MicroRNAs - chemistry / MicroRNAs - genetics / MicroRNAs - metabolism / miRNA / mRNA stability / Nanog Homeobox Protein / Nucleic acids / Osteopontin / Periodontal ligament / Pharmaceutical sciences / Phase transitions / Phenotype / Political aspects / Population / Rehabilitation / Side-Population Cells - metabolism / Stem cells / Stem Cells - cytology / Stem Cells - metabolism / Studies / Transcription / Transcription (Genetics) / Transcription, Genetic / Transfection / Translation (Genetics) / University graduates