Effect of lncRNA TUG1 on osteogenic/odontogenic differentiation of human dental pulp stem cells

To explore the effects of long noncoding-RNA (lncRNA) taurine upregulated gene 1 (TUG1) on the proliferation and osteogenic/odontoblast differentiation of human dental pulp stem cells (hDPSCs).

hDPSCs were isolated and cultured. The surface antigens CD44, CD45, CD73, CD90, CD133 and STRO-1 were detected by flow cytometry. Alkaline phosphatase (ALP) staining and alizarin red staining were used to identify the ability of cells to differentiate. RNA was collected on Days 0, 7 and 14 of the osteogenic induction of hDPSCs, and qRT-PCR was used to detect the relative expression of TUG1. The hDPSCs were stably transfected with a lentiviral vector containing the TUG1-silenced pSLenti-U6-shRNA(TUG1)-CMV-EGFP-F2A-Puro-WPRE to silence TUG1. The ability of hDPSCs to proliferate was assessed with the CCK-8 method. ALP and alizarin red staining and quantitative detection were used to detect the ALP activity and formation of mineralized nodules of hDPSCs. The expression levels of dentin sialophosphoprotein (DSPP), dentin matrix protein-1 (DMP-1), Runt-associated transcription factor 2 (Runx2), osteocalcin (OCN) and osteopontin (OPN) genes and proteins were measured by qRT-PCR and Western blot.

The hDPSCs were successfully isolated and cultured, and TUG1 expression was significantly increased during osteogenic differentiation (P<0.05). The hDPSCs proliferation was suppressed after silencing TUG1(P<0.05). After osteogenic induction, ALP and alizarin red staining showed that ALP activity and mineralized nodules were suppressed by silencing TUG1. The expression levels of the odontogenic differentiation gene DSPP and DMP-1 and the osteogenic differentiation gene Runx2, OCN and OPN were also significantly decreased (P<0.05).

Knocking down TUG1 can inhibit the proliferation and osteogenic/odontogenic differentiation of hDPSCs.