Oxytocin facilitates the proliferation, migration and osteogenic differentiation of human periodontal stem cells in vitro.

Abstract

OBJECTIVE\nTo explore the effect of oxytocin (OT) on the proliferation, migration, and osteogenic differentiation of periodontal ligament stem cells (PDLSCs) in vitro.\n\n\nDESIGN\nPDLSCs were obtained by limiting dilution method. Immunofluorescence (IF), cell-counting kit-8 (CCK8), cell migration assay, Alizarin Red S staining, cetylpyridinium chloride (CPC) colorimetry, quantitative real-time polymerase chain reaction (qRT-PCR), and western blot analysis were used to examine the effect of OT on oxytocin receptor (OTR) expression, cell proliferation, migration and osteogenic differentiation of PDLSCs.\n\n\nRESULTS\nOur study showed that PDLSCs expressed OTR. One hundred nanomolar OT exhibited the maximal effect on migration, while only 50\u2009nM OT significantly promoted proliferation of PDLSCs, as well as mineralized nodule formation and calcium deposition (p\u2009<\u20090.05). Furthermore, 50\u2009nM OT significantly up-regulated expression of osteogenesis-related genes-alkaline phosphatase (ALP), Collagen I (Col I), runt related transcription factor 2 (Runx 2), osteopontin (OPN) and osteocalcin (OCN)-at specific time points compared with osteogenic inductive medium (p\u2009<\u20090.05). In addition, western blot analysis demonstrated that 50\u2009nM OT enhanced protein levels of ALP, Col I, and Runx 2 at day 7 and day 14 (p\u2009<\u20090.01), as well as activating the phosphorylation of extracellular-signal-regulated kinase (ERK) and protein kinase B (AKT) pathway; notably, 50\u2009nM OT inhibited phosphorylation of the phosphatidylinositol 3-kinase (PI3K) pathway (p\u2009<\u20090.05).\n\n\nCONCLUSIONS\nOT promoted proliferation, migration, and osteogenic differentiation of PDLSCs in vitro. Furthermore, the effect of OT on osteogenic differentiation was mediated through ERK and AKT pathway. Thus, OT may have potential for use in periodontal regeneration.