Overview of noncoding RNAs involved in the osteogenic differentiation of periodontal ligament stem cells

Figure 2 Regulatory mechanisms of noncoding RNAs associated with the osteogenic differentiation of periodontal ligament stem cells. Red indicates miRNAs, green indicates mRNAs, blue indicates long noncoding RNAs and purple indicates circular RNAs. Collectively, the regulatory mechanism of miRNAs is to directly bind to the 3’-UTR of target genes and inhibit the mRNA levels or protein expression. Long noncoding RNAs regulate the osteogenic differentiation of periodontal ligament stem cells at the transcriptional, posttranscriptional or epigenetic level. And the demonstrated mechanism of circular RNAs is to act as miRNA sponges to inhibit the mRNA levels of target genes. ATF4: Activated transcription factor 4; CTNNB1: Catenin beta 1; TCF3: Transcriptional factor 3; Smurf1: Smad ubiquitin regulatory factor 1; Spry1: Palmitate phosphoprotein Sprouty1; ACVR2B: Activin A receptor type 2B; Smad5: SMAD family member 5; Runx2: Runt-related transcription factor 2; TOB2: Transducer of ERBB2; Satb2: Special AT-rich sequence-binding protein 2; IL-6: Interleukin-6; CDR1as: Antisense to the cerebellar degeneration-related protein 1 transcript; GDF5: Growth differentiation factor 5; HDAC6: Histone deacetylase 6; HIF-1α: Hypoxia-inducible factor-1α; HIF1A‑AS1/2: HIF1A antisense RNA 1/2; PCAT1: Prostate cancer-associated ncRNA transcript-1; E2F5: E2F transcription factor 5; POIR: Osteogenesis impairment-related long noncoding RNA of periodontal ligament stem cells; FoxO1: Forkhead box O1; ANCR: Anti-differentiation noncoding RNA; Notch2: Neurogenic locus notch homolog protein 2; TUG1: Taurine upregulated gene 1; Lin28A: Lin-28 homolog A; MEG3: Maternally expressed gene 3; hnRNP I: Heterogeneous nuclear ribonucleoprotein I; EZH2: Enhancer of zeste homolog 2; BMP2: Bone morphogenetic protein-2; ALP: Alkaline phosphatase, OCN: Osteocalcin; OSX: Osterix; BSP: Bone sialoprotein; miR: MicroRNA; ncRNAs: Non-coding RNAs.