CKIP-1 suppresses odontoblastic differentiation of dental pulp stem cells via BMP2 pathway and can interact with NRP1

ABSTRACTAim: Casein kinase 2 interacting protein-1 (CKIP-1) is a recently discovered intracellular regulator of bone formation, muscle cell differentiation, and tumor cell proliferation. Our study aims to identify the inhibition of BMP2-Smad1/5 signaling by CKIP-1 in odontoblastic differentiation of human dental pulp stem cells (DPSCs). Materials and Methods: DPSCs infected CKIP-1 siRNA or transfected CKIP-1 full-length plasmid were cultured in odontoblastic differentiation medium or added noggin (200 ng/mL) for 21 days. We examined the effects of CKIP-1 on odontoblastic differentiation, mineralized nodules formation, and interaction by western blot, real-time polymerase chain reaction (RT-PCR), alkaline phosphatase (ALP) staining, alizarin red S staining, and immunoprecipitation. Results: Firstly, we have demonstrated that CKIP-1 expression markedly decreased time-dependently along with cell odontoblastic differentiation. Indeed, the silence of CKIP-1 upregulated odontoblastic differentiation via BMP2-Sm...