The Immunomodulatory Properties of Periodontal Ligament Stem Cells Isolated from Inflamed Periodontal Granulation

Abstract

Periodontitis is currently the main cause of tooth loss and as yet there is no appropriate method for establishing a functional and predictable periodontal regeneration. Tissue engineering involving seed cells provides a new prospect for periodontal regeneration. While periodontal ligament stem cells (PDLSCs) are a good choice for seed cells, it is not always possible to obtain the patients' own PDLSCs. We and others have found a type of stromal cells from inflamed periodontal granulation. These cells displayed similar differentiation properties to PDLSCs. Inflammation has a profound influence on the immunomodulatory properties of mesenchymal stem cells, which may affect therapeutic outcome. In this study, we assessed the immunomodulatory characteristics of these inflamed human (ih)PDLSCs. Along with the similarity in cell surface marker expressions, they also displayed immunomodulatory properties comparable to those in healthy human (hh)PDLSCs. Both hhPDLSCs and ihPDLSCs can suppress the proliferation and secretion of IFN-γ in peripheral blood mononuclear cells by indirect soluble mediators and direct cell-cell contact. Albeit with some quantitative variances, the gene expressions of inducible nitric oxide synthases, indoleamine 2,3 dioxygenase, cyclooxygenase-2, TNF-α-induced protein 6 and IL-10 in ihPDLSCs displayed similar patterns as those in hhPDLSCs. Taken together, our results suggest that ihPDLSCs can provide a promising alternative to hhPDLSCs in terms of evident similarities in immunomodulatory properties as well as their easier accessibility and availability.

Stem cells derived from “inflamed” and healthy periodontal ligament tissues and their sheet functionalities: a patient‐matched comparison

“…, Li et al. ). Despite these differences, we noted that both types of cells displayed acceptable immunomodulatory activity, and interestingly, no significant difference in the suppression of IL‐10 production by the two types of PDLSCs was observed (Fig.…”

“…, Li et al. ), it is difficult to reach a conclusion regarding how and to what extent periodontal inflammation may impact the function of PDLSCs due to differences in both donor groups and tissue sources. Previous studies were specifically limited by a lack of confidence that the “inflamed” tissues used for cell isolation were of pure PDL origin, by a lack of exact age matching of the two groups, or both.…”

“…, Li et al. ). Furthermore, typical mesenchymal stem cells (MSCs) derived from other human chronic granulomatous tissues, such as periapical lesions, have been demonstrated to possess both multilineage differentiation potential and immunosuppressive properties (Dokić et al.…”

Pathological Examination of Experimentally Induced Periodontal Polyp in Mice

“…Due to the experimental perforation of the floor of the pulp chamber in mice, growth of chronic inflammatory granulation tissue was found to be the main tissue change without causing purulent inflammation. Recently, several studies mentioned that the cellular components of the granulation tissue were derived from the periodontal ligament stem cells (PDLSCs) [9][10][11] . We utilized bone marrow transplanted GFP mouse to analyze cell differentiation and migration in periodontal tissue.…”

A prospective cohort study of immediate implant placement into posterior compromised sockets with or without primary wound closure of reactive soft tissue

“…In addition, mesenchymal stem cells, which were highly osteogenic, were isolated from inflamed periapical or periodontal granulation tissue and, when transplanted into an ectopic animal model, they generated mineralized tissues, dropping hints about regenerative potential . Furthermore, immunomodulatory properties of these stem cells were retained, since they expressed the same levels of immunoregulatory surface markers, inhibited the proliferation of peripheral blood mononuclear cells and downregulated the secretion of proinflammatory cytokines, similar to those derived from healthy periodontal tissue . Taken together, stem cells from the preserved granulation tissue presumably contribute to bone formation and also control of inflammation.…”