Exosomes derived from P2X7 receptor gene-modified cells rescue inflammation-compromised periodontal ligament stem cells from dysfunction

Abstract

Although cellular therapy has been proposed for inflammation-related disorders such as periodontitis for decades, clinical application has been unsuccessful. One explanation for these disappointing results is that the functions of stem cells are substantially compromised when they are transplanted into an inflammatory in vivo milieu. Considering the previous finding that P2X7 receptor (P2X7R) gene modification is able to reverse inflammation-mediated impairment of periodontal ligament stem cells (PDLSCs), we further hypothesized that cells subjected to P2X7R gene transduction also exert influences on other cells within an in vivo milieu via an exosome-mediated paracrine mechanism. To define the paracrine ability of P2X7R gene-modified cells, P2X7R gene-modified stem cell-derived conditional medium (CM-Ad-P2X7) and exosomes (Exs-Ad-P2X7) were used to incubate PDLSCs. In an inflammatory osteogenic microenvironment, inflammation-mediated changes in PDLSCs were substantially reduced, as shown by quantitative real-time PCR (qRT-PCR) analysis, Western blot analysis, alkaline phosphatase (ALP) staining/activity assays, and Alizarin red staining. In addition, the Agilent miRNA microarray system combined with qRT-PCR analysis revealed that miR-3679-5p, miR-6515-5p, and miR-6747-5p were highly expressed in Exs-Ad-P2X7. Further functional tests and luciferase reporter assays revealed that miR-3679-5p and miR-6747-5p bound directly to the GREM-1 protein, while miR-6515-5p bound to the GREM-1 protein indirectly; these effects combined to rescue inflammation-compromised PDLSCs from dysfunction. Thus, in addition to maintaining their robust functionality under inflammatory conditions, P2X7R genemodified stem cells may exert positive influences on their neighbors via a paracrine mechanism, pointing to a novel strategy for modifying the harsh local microenvironment to accommodate stem cells and promote improved tissue regeneration. Xin-Yue Xu, Bei-Min Tian, and Yu Xia contributed equally to this work.

Therapeutic Features and Updated Clinical Trials of Mesenchymal Stem Cell (MSC)-Derived Exosomes

“…Dysbiosis in the periodontal cavity promotes the growth of pathogenic microbiota such as Porphyromonas gingivalis and Fusobacterium nucleatum , contributing to autoantibody generation and subversion of host immune responses after invasion of these autoantibodies into the circulatory system and various organs [ 63 ]. Xu et al demonstrated that exosomes from P2 × 7 receptor (P2 × 7R) gene-modified periodontal ligament stem cells (PDLSCs) restored the compromised regenerative function of neighboring cells by binding to the GREM-1 protein and upregulating the expression of miRNAs including miR-3679-5p, miR-6515-5p, and miR-6747-5p [ 64 ]. Exosomal microRNA-155-5p from PDLSCs directly rectified the imbalance in the Th17/Treg ratio by regulating the expression of sirtuin-1 (SIRT1) in a chronic periodontitis experimental model [ 65 ].…”

Exosomes Isolated From Bone Marrow Mesenchymal Stem Cells Exert a Protective Effect on Osteoarthritis via lncRNA LYRM4-AS1-GRPR-miR-6515-5p

“…GRPR, a gastrin-releasing peptide receptor, has been reported to be involved in the healing process in the synovium in patients with OA (Grimsholm et al, 2008). Xu et al (2020) demonstrated that miR-6515-5p was highly expressed in P2 × 7R gene-modified stem cell-derived exosomes and reduced inflammation-mediated impairment of periodontal ligament stem cells through indirect binding to the GREM-1 protein. Together with our results, we speculate that exosomes isolated from human BMSCs may regulate chondrocyte growth by the LYRM4-AS1/GRPR/miR-6515-5p signal axis, reducing inflammation in OA.…”

Immunomodulation in the Treatment of Periodontitis: Progress and Perspectives

“…It has been found that the gene modification of the P2X7 receptor (P2X7R) can promote the repair of inflammatory lesions in PDLSCs. In addition to maintaining their robust functionality under inflammatory conditions, P2X7R gene-modified stem cells may have positive influences on their neighbors through paracrine mechanism, suggesting a novel strategy to modify the harsh local microenvironment of periodontitis to accommodate stem cells and promote improved tissue regeneration (206).…”