MiR-375 promotes human periodontal ligament stem cells proliferation and osteogenic differentiation by targeting transducer of ERBB2, 2

Background: MiRNAs have been demonstrated to be important regulators during osteogenic differentiation in multiple types of stem cells. In the study, the interaction between miR-375 and TOB2 was analyzed to identify their functions on the proliferation and osteogenic differentiation of hPDLSCs.

Methods: hPDLSCs were isolated from human first premolars, and hPDLSCs stably expressing and silenced miR-375 were constructed using miR-375-ago and miR-375-antago, respectively. miR-375 and RUNX2 mRNA expression levels in hPDLSCs during osteogenic differentiation were investigated using qRT-PCR. The impact of miR-375 expression on hPDLSCs proliferation and osteogenic differentiation was determined using MTT assay, ALP assay, and alizarin red S staining. The protein expression levels of COL1A1, RUNX2 and OCN were detected using Western blot. The targeting of TOB2 by miR-375 was validated using dual luciferase reporter assay.

Results: The expression levels of miR-375 were increased in hPDLSCs during osteogenic differentiation in a time-dependant manner, and was positively correlated with RUNX2 mRNA expression. miR-375 facilitated the proliferation and osteogenic differentiation of hPDLSCs, and promoted the protein expression levels of COL1A1, RUNX2 and OCN. Moreover, TOB2 protein expression was reduced in hPDLSCs during osteogenic differentiation in a time-dependant manner, and miR-375 directly targeted TOB2 expression. In addition, targeting TOB2 expression in hPDLSCs could rescue the suppression of cell proliferation and osteogenic differentiation by miR-375-antago.

Conclusion: In summary, miR-375 promotes proliferation and osteogenic differentiation of hPDLSCs by targeting TOB2, which reveals a new regulatory mechanism underlying osteogenic differentiation of hPDLSCs by miR-375/TOB2 axis.