LncRNA CALB2 sponges miR-30b-3p to promote odontoblast differentiation of human dental pulp stem cells via up-regulating RUNX2.

Illuminating the mechanisms of odontoblast differentiation of human dental pulp stem cells (hDPSCs) is the key to find therapeutic clues to promote odontogenesis. LncRNAs play a regulatory role in odontoblast differentiation. Here, we identified a novel lncRNA, named lncRNA CALB2. It was up-regulated in odontoblast-differentiated hDPSCs and potentially interacted with miR-30b-3p and RUNX2. Via gain- and loss-of-function approaches, we found lncRNA CALB2 significantly promoted the odontoblast differentiation of hDPSCs. Then, dual luciferase reporter assay and RNA immunoprecipitation assay revealed that both lncRNA CALB2 and RUNX2 mRNA could directly bind to miR-30b-3p via the same binding sites. Interestingly, miR-30b-3p in hDPSCs was down-regulated and RUNX2 was up-regulated during odontoblast differentiation. Moreover, lncRNA CALB2 knockdown significantly reduced the protein level of RUNX2, DSPP and DMP-1, while miR-30b-3p inhibitor rescued the reduction. Furthermore, miR-30b-3p exerted an inhibitory effect on odontoblast differentiation, which could be reversed by lncRNA CALB2. Collectively, these findings indicate that the newly identified lncRNA CALB2 acts as a miR-30b-3p sponge to regulate RUNX2 expression, thus promoting the odontoblast differentiation of hDPSCs. LncRNA CALB2/miR-30b-3p/RUNX2 axis could be a novel therapeutic target for accelerating odontogenesis.