Conditioned Medium from Periodontal Ligament Stem Cells Enhances Periodontal Regeneration

Abstract

Periodontal disease is one of the most common infectious diseases in adults and is characterized by the destruction of tooth-supporting tissues. Mesenchymal stem cells (MSCs) comprise the mesoderm-originating stem cell population, which has been studied and used for cell therapy. However, because of the lower rate of cell survival after MSC transplantation in various disease models, paracrine functions of MSCs have been receiving increased attention as a regenerative mechanism. The aim of this study was to investigate the regenerative potential of transplanted conditioned medium (CM) obtained from cultured periodontal ligament stem cells (PDLSCs), the adult stem cell population in tooth-supporting tissues, using a rat periodontal defect model. Cell-free CM was collected from PDLSCs and fibroblasts, using ultrafiltration and transplanted into surgically created periodontal defects. Protein content of CM was examined by antibody arrays. Formation of new periodontal tissues was analyzed using microcomputed tomography and histological sections. PDLSC-CM transplantation enhanced periodontal tissue regeneration in a concentration-dependent manner, whereas fibroblast-CM did not show any regenerative function. Proteomic analysis revealed that extracellular matrix proteins, enzymes, angiogenic factors, growth factors and cytokines were contained in PDLSC-CM. Furthermore, PDLSC-CM transplantation resulted in the decreased mRNA level of tumor necrosis factor-α (TNF-α) in healing periodontal tissues. In addition, we found that PDLSC-CM suppressed the mRNA level of TNF-α in the monocyte/macrophage cell line, RAW cells, stimulated with IFN-γ. Our findings suggested that PDLSC-CM enhanced periodontal regeneration by suppressing the inflammatory response through TNF-α production, and transplantation of PDLSC-CM could be a novel approach for periodontal regenerative therapy.

Dental Stem Cell-Derived Secretome/Conditioned Medium: The Future for Regenerative Therapeutic Applications

“…Stem/Progenitor Cell-Derived Secretome/Conditioned Medium The periodontal ligament is considered a potent source of stem/progenitor cells for tissue regeneration that can differentiate into several types of cells [178][179][180]. They are the most favorable stem/progenitor cell population utilized in periodontal regeneration [181], due to their high expression of scleraxis, a protein responsible for the formation of the cementum-periodontal ligament complex [37]. Human periodontal ligament MSCs are similar to bone marrow MSCs, with high proliferative rate, immunomodulatory functions, and an in vitro differentiation ability into osteogenic, adipogenic, chondrogenic, and neurogenic cell lineages [182][183][184].…”

Changes in characteristics of periodontal ligament stem cells in spheroid culture

“…We have previously reported that decreased levels of tumor necrosis factor α (TNFα) were correlated with the regeneration of periodontal tissues; this suggested positive relationships between the inhibition of inflammation and periodontal regeneration. 35 These results, together with the enhanced gene expression in PDLSC spheroid, inspired us to examine the regenerative function of PDLSC spheroids in vivo. However, we did not find the regeneration of periodontal tissues by transplanting of PDLSC spheroids into periodontal defects in rats, although the sample size was small.…”

“…Male nude rats were used in this study (F344/N‐Jcl‐rnu/rnu; 7‐10 weeks of age; n = 6). Surgical procedures were performed as described in previous studies . Briefly, an incision of 1‐1.5 cm was made at the bottom of the mandible, and the buccal plate was exposed.…”

“…Surgical procedures were performed as described in previous studies. 35,37,38 Briefly, an incision of 1-1.5 cm was made at the bottom of the mandible, and the buccal plate was exposed. Then, the periodontal defects of 2 × 3 mm were created in the buccal area of mandible first molar.…”

“…It has been confirmed that PDLSCs isolated using this method demonstrate MSC-like characteristics, such as cell surface marker expression (CD105+, CD90+, CD44+, CD146+, CD166+, CD45−, CD31−, CD34−) and the capacity to differentiate into osteoblasts, adipocytes, and chondrocytes. 35,36…”