Comprehensive analysis of circRNA expression profiles in p75NTR-knockout ecto- mesenchymal stem cells

Neural crest-derived ecto-mesenchymal stem cells (EMSCs), as the progenitor cells of odontogenic stem cells, may be the suitable seed cell for regenerative dentistry. p75NTR, as the neural crest stem cell marker, plays a crucial role during the teeth development of EMSCs. Nevertheless, the interaction networks p75NTR connecting with odonto/osteogenic differentiation and mineralization are still poorly studied. Circular RNAs (circRNAs) regulate life processes mainly by performing as a competitive endogenous RNA (ceRNA) to prevent the process that microRNAs (miRNAs) bind with their target mRNAs. But the roles of p75NTR-related circRNAs in EMSCs are largely unknown. We used circRNA-seq to examine the differentially expressed circRNAs between WT and p75NTR (-/-) EMSCs and three of them were selected for qRT-PCR verification. GO, KEGG and Reactome enrichment analyses showed that differentially expressed circRNAs interact with cell proliferation, locomotory behavior, cell differentiation and are mainly involved in Wnt, JAK/STAT, Hippo and TGF-β signaling pathways. Then, CCK8, transwell assay and ALP staining assay were performed to verify the result of enrichment analyses. Then, the circRNA-miRNA interaction networks were constructed by using bioinformatics analysis. A new circRNA, mmu_circ_0001380 and mmu_circ_0013536 were selected to predict potential target miRNAs. Besides, with TargetScan, we noticed that these three circRNAs may influence the expression of DSPP and RUNX2 and qRT-PCR was performed for verification. Therefore, these three circRNAs are inclined to be vital in developing EMSCs and be novel core molecules for the further understanding of odontogenesis related to p75NTR.