Pluripotency of Dental Pulp Cells and Periodontal Ligament Cells Was Enhanced through Cell-Cell Communication via STAT3/Oct-4/Sox2 Signaling

Figure 7

STAT3 bound to the endogenous Oct-4/Sox2 promoters. (a) Oligonucleotide sequences indicating the Oct-4/Sox2 promoters and the distance from the transcription start site (TSS) are shown. Green arrows denote the transcription direction. (b) The relative luciferase activities of the Oct-4 and Sox2 mutants were significantly decreased when compared with the STAT3 mimic in cotransfected 293 T cells. Data are represented as the . , , and ; wild-type (WT) vs. mutation (MUT). (c) STAT3 binding to the endogenous Oct-4 and Sox2 promoters was evaluated by the chromatin immunoprecipitation assay. The levels of Oct-4 and Sox2 promoter regions in the lower chamber DPCs were significantly higher than those in the control group. (d) The binding sites for STAT3 on Oct 4 and Sox2 were detected by the electrophoretic mobility shift assay (EMSA) performed with DIG-labeled oligonucleotide probes (lane 2). Incubation with a specific competitor abolished the binding (lane 3), while addition of a mutant competitor increased the intensities of the putative bands (lane 4). Moreover, incubation with STAT3 antibody reduced the intensities of those bands while causing an upward super shift (lane 5).

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