Roles of L-type calcium channels (Ca1.2) and the distal C-terminus (DCT) in differentiation and mineralization of rat dental apical papilla stem cells (rSCAPs).

Objective: Voltage-gated inward Ca currents (ICa) are triggered by cell depolarization and commonly produce transient increases in the cytoplasmic free Ca concentration. The Ca1.2 distal C-terminus is susceptible to proteolytic cleavage, which yields a truncated Ca1.2 subunit and a cleaved C-terminal fragment (CCt or DCT). Stem cells from the apical papilla (SCAPs) has a capacity for differentiation into the odontoblastic-like cells in vitro and dentin forming in vivo, which makes SCAPs advantages in tissue engineering and regenerative endodontic. The aim of this study was to investigate the effect of Ca1.2 and its distal C-terminal fragment in the odontoblastic differentiation of rat SCAPs (stem cells from the apical papilla).

Design: In this study, we generated stable Ca1.2 knockdown and DCT over-expressed rSCAPs using short hairpin RNA and DCT gene containing Lentivirus vectors, respectively. The transfected apical papilla cells were induced to differentiate into the odontoblast-like cells, and the expression of markers for odontoblastic differentiation were analyzed by alizarin red staining, Real-time Polymerase chain reaction (RT-PCR), and Western blot analysis.

Results: The knockdown of Ca1.2 and excess expression of DCT both suppressed the expression of DSPP, ALP in mRNA level and the formation of calcium nodules.

Conclusions: Our results suggest that Ca1.2 and DCT play important roles in the differentiation of rSCAPs, DCT might act as a transcription factor and regulate the differentiation of rSCAPs.