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

Abstract

Alternation in culture environment due to cell-cell communications can rejuvenate the biological activity of aged/differentiated cells and stimulate the expression of pluripotency markers. Dental pulp cells (DPCs) and periodontal ligament cells (PDLCs) are promising candidates in dental tissue regeneration. However, the molecular network that underlies cell-cell communications between dental-derived cells and the microenvironment remains to be identified. To elucidate the signaling network that regulates the pluripotency of DPCs and PDLCs, proliferation, apoptosis, cell cycle, and the expression of Oct-4/Sox2/c-Myc in DPCs and PDLCs with indirect/direct coculture were examined. PCR arrays were constructed to identify genes that were differentially expressed, and the results were confirmed by a rat model with injury. Further research on the mechanism of the related signaling pathways was investigated by overexpression/silence of STAT3, ChIP, the dual-luciferase reporter assay, and EMSA. We found that the proliferation and apoptosis of DPCs and PDLCs were inhibited, and their cell cycles were arrested at the G0/G1 phase after coculture. Oct-4, Sox2, and STAT3 expression significantly increased and PAX5 expression decreased in the coculture systems. Oct-4/Sox2/STAT3/PAX5 was actively expressed in the rat defect model. Moreover, STAT3 was directly bound to the Oct-4 and Sox2 gene promoter regions and activated the expression of those genes. Our data showed that the pluripotency of DPCs and PDLCs was enhanced through cell-cell communication. STAT3 plays essential roles in regulating the pluripotency of DPCs and PDLCs by targeting Oct-4 and Sox2 both in vitro and in vivo.

Pluripotency of periodontal ligament and dental pulp cells is induced by intercellular communication via the CDX2/Oct-4/Sox2 pathway

“…In a previous study, we demonstrated that cell-cell communication between DPCs and PDLCs enhances the differentiation potential of both cell types, as shown by increased numbers of calcified nodules, elevated ALP activity, and adipogenic differentiation (15). In the present study, we observed the significant upregulation of Oct-4 and Sox2 levels after co-cultures.…”

“…Chromatin Immunoprecipitation (ChIP) assays were conducted to confirm that CDX2 interacts with the Oct-4 and Sox2 promoters (see Figure 3D). As previously shown (15), the promoter levels of both genes were raised in comparison to those of the controls. Then the probes with mutations in the CDX2-Oct-4/Sox2 interaction regions were used for the EMSAs (see Figures 3E,3F).…”

“…Intercellular communication in the culture environment can stimulate the expression of pluripotency markers in differentiated cells (15). Cells can be maintained in an undifferentiated state in culture by the addition of specific factors or the use of feeder cells (16)(17)(18).…”

Nuclear Factor I-C Regulates Stemness Genes and Proliferation of Stem Cells in Various Mineralized Tissue through Epithelial-Mesenchymal Interactions in Dental Epithelial Stem Cells

“…However, Li Zhang et al reported that sox2 mRNA expression was strongly expressed in OEE and SI but weakly expressed in dental mesenchyme and dental follicle [ 43 , 44 ]. In addition, Peng et al reported that Sox2 was expressed in the dental papilla and dental follicle in a time-dependent manner [ 45 , 46 ]. We confirmed that level of Sox2 protein in P14-old wild-type mice was strongly expressed in OEE and SI but not in the dental mesenchyme and dental follicle (data not shown).…”

Therapeutic potential of periodontal ligament stem cells

“…The pluripotent embryonic stem cells markers NANOG[ 30 , 34 , 37 ], OCT-4[ 30 , 34 , 37 , 38 ], SOX2[ 34 , 37 , 38 ], SSEA-1[ 30 , 37 ], SSEA-3[ 37 ], SSEA-4[ 30 , 37 ], TRA-1-60, and TRA-1-81[ 37 ] were also reported to be expressed by PDLSCs, which may indicate an even more undifferentiated state of these cells. In a recent study, we reported that about 10% of PDLSCs could present double positivity for SOX2 and OCT-4[ 38 ], two transcription factors important for the pluripotency of embryonic stem cells, but which are also detected in somatic stem cells, such as those derived from the periodontal ligament[ 39 ].…”