CREB1 alleviates the apoptosis and potentiates the osteogenic differentiation of zoledronic acid-treated human periodontal ligament stem cells via up-regulating VEGF

Abstract

Periodontitis represents a severe inflammatory illness in tooth supporting tissue. It has been supported that cAMP response element binding protein 1 (CREB1), a common transcription factor, extensively participates in osteogenic differentiation. Here, the current study was to look into the impacts of CREB1 on the process of periodontitis and its possible action mechanism. After human periodontal ligament stem cells (PDLSCs) were challenged with zoledronic acid (ZA), CREB1 expression was examined with RT-qPCR and western blotting. CCK-8 assay appraised cell activity. Following CREB1 elevation or/and vascular endothelial growth factor (VEGF) silencing in ZA-treated PDLSCs, CCK-8 and TUNEL assays separately estimated cell viability and apoptosis. Western blotting tested the expression of apoptosis- and osteogenic differentiation-associated proteins. ALP staining measured PDLSCs osteogenic ability and ARS staining estimated mineralized nodule formation. JASPAR predicted the potential binding of CREB1 with VEGF promoter, which was then testified by ChIP and luciferase reporter assays. RT-qPCR and western blotting tested VEGF expression. CREB1 expression was declined in ZA-exposed PDLSCs and CREB1 elevation exacerbated the viability and osteogenic differentiation while obstructed the apoptosis of PDLSCs. Additionally, CREB1 bond to VEGF promoter and transcriptionally activated VEGF expression. Further, VEGF absence partially stimulated the apoptosis while suppressed the osteogenic differentiation of CREB1-overexpressing PDLSCs treated by ZA. To be concluded, CREB1 might activate VEGF transcription to obstruct the apoptosis while contribute to the osteogenic differentiation of ZA-treated PDLSCs.