Induced Overexpression of Oct4A in Human Dental Pulp Cells Enhances Pluripotency and Multilineage Differentiation Capability

摘要

Octamer-binding transcription factor 4A (Oct4A), one of the three spliced variants of the class V of POU transcription factor family, is mainly expressed in the nucleus of undifferentiated cells and serves as the key regulator for the maintenance of pluripotency and self-renewal. However, its specific role in regulating pluripotency and multilineage differentiation potential of dental pulp cells (DPCs) remains unknown. To explore the effect of Oct4A on pluripotency and multilineage differentiation capability of DPCs, expression of Oct4A in human dental pulp tissue and pluripotent markers Oct4A, Sox2, c-Myc, Nanog, and Klf4 in DPCs with prolonged in vitro culture were examined by immunohistochemistry and immunofluorescent staining. Oct4A transfection rate in DPCs with lentivirus was evaluated by real-time polymerase chain reaction (PCR) and western blot. Cell proliferation, multilineage differentiation, and the expression of Oct4B1, Sox2, Nanog, Klf4, c-Myc, and Utf1 in DPCs after Oct4A transfection were detected by cell counting kit-8, Alizarin red/Oil red O staining, immunofluorescent staining, alkaline phosphatase analysis, and real-time PCR. We demonstrated that Oct4A was mainly expressed in the nucleus of odontoblasts in dental pulp tissue. Oct4A, Sox2, c-Myc, Nanog, and Klf4 were primarily located in the nucleus of DPCs at early passage (passage 1) and translocated to cytoplasm at late passage (passage 7). In DPCs with Oct4A overexpression, Oct4A, Oct4B1, Sox2, Nanog, Klf4, c-Myc, and Utf1 were significantly upregulated (p<0.05) and the cell proliferation (p<0.05), odontogenic and adipogenic differentiation were significantly enhanced. Taken together, Oct4A plays a critical role in regulation of cell proliferation, pluripotency, and multilineage differentiation potential of DPCs.