Project description:Neutrophil recruitment and activation are hallmarks of the prevalent inflammatory disease, periodontitis. However, the mechanisms by which neutrophils contribute to in inflammatory bone destruction remain unclear. Herein, we document that neutrophil extracellular traps (NETs) have a direct role in mediating inflammatory pathology. In an established animal model of periodontitis, we demonstrate that genetic or pharmacologic inhibition of NETs formation, or removal of NETs by DNase-Ⅰ, alleviates inflammatory bone loss in vivo. Investigating the mechanisms by which NETs drive periodontal inflammation, we find that extracellular histones have a direct role in disease progression. Consistent with findings in animal models, histones bearing classic NET-associated post-translational modifications are correlated with disease severity and are significantly elevated in local lesions and systemic circulation of patients with periodontitis. Our work reveals NETs-associated components as pathogenic mediators, potential biomarkers, and therapeutic targets for periodontitis.
Project description:We performed single-cell RNA-sequencing analysis on mouse periodontal lesions to analyze the detailed mechanism underlying immune–bone cell interactions in periodontitis.
Project description:The oral mucosa remains an understudied barrier tissue rich in exposure to antigens, commensals and pathogens. Moreover, it is the tissue where one of the most prevalent human microbe-triggered inflammatory diseases, periodontitis, occurs. To understand this complex environment at the cellular level, we assemble herein a human single-cell transcriptome atlas of oral mucosal tissues in health and periodontitis. Our work reveals transcriptional diversity of stromal and immune cell populations, predicts intercellular communication and uncovers an altered immune responsiveness of stromal cells participating in tissue homeostasis and disease at the gingival mucosa. In health, we define unique populations of CXCL1,2,8- expressing epithelial cells and fibroblasts mediating immune homeostasis primarily through the recruitment of neutrophils. In disease, we further observe stromal, particularly fibroblast hyper-responsiveness linked to recruitment of leukocytes and neutrophil populations. Our work suggests a stromal-neutrophil axis as a key regulator of mucosal immunity. Pursuant to these findings, most Mendelian forms of periodontitis were shown to be linked to genetic mutations in neutrophil-expressed genes. Moreover, we document previously unappreciated expression of known pattern- and damage- recognition receptors on stromal cell populations in the setting of periodontitis, suggesting avenues for triggering of stromal responsiveness. This comprehensive atlas offers an important reference for in-depth understanding of oral mucosal homeostasis and inflammation and reveals unique stromal–immune interactions implicated in tissue immunity.
Project description:Single cell analysis of PDL cells in ligature-induced periodontitis: The periodontal ligament (PDL) is a fibrillar connective tissue that lies between the alveolar bone and the tooth and is composed of highly specialized extracellular matrix (ECM) molecules and a heterogeneous population of cells that are responsible for collagen formation, immune response, bone formation, and chewing force sensation. Type VI collagen (COL6), a widely distributed ECM molecule, plays a critical role in the structural integrity and mechanical properties of various tissues including muscle, tendon, bone, cartilage, and skin. However, its role in the PDL remains largely unknown. Our study shows that deficiency of COL6 impairs PDL fibrogenesis and exacerbates tissue destruction in ligature-induced periodontitis (LIP). We found that COL6 deficient mice exhibited increased bone loss and degraded PDL in LIP and that fibroblasts expressing high levels of Col6α2 are pivotal in ECM organization and cell-ECM interactions. Moreover, COL6 deficiency in the PDL led to an increased number of fibroblasts geared towards the inflammatory response. We also observed that cultured COL6 deficient fibroblasts from the PDL exhibited decreased expression of genes related to collagen fiber metabolism and ECM organization, and migration and proliferation. Our findings suggest that COL6 plays a crucial role in the PDL, influencing fibroblast function in fibrogenesis and affecting the immune response in periodontitis. These insights could advance our understanding of the molecular mechanisms underlying PDL maturation and periodontal disease.
Project description:Treatment of periodontitis in people with diabetes remains challenging. Diabetes-enhanced oxidative stress is a primary cause of aggravation of periodontitis. The present study aimed to investigate the therapeutic potential of thioredoxin-1 (TRX1), an essential endogenous antioxidant protein, in the management of periodontitis with diabetes, as well as its role in modulating osteogenic differentiation. Our findings indicated that the production of reactive oxygen species (ROS) was elevated, while the expression of TRX1 was significantly reduced in the periodontal tissues of periodontitis mice with diabetes. Furthermore, knockdown of TRX1 in periodontal ligament stem cells (PDLSCs) resulted in the inhibition of osteogenic differentiation through disrupting Wnt/β-catenin signal pathway. However, this inhibition was restored upon administration of recombinant human TRX1 (rhTRX1). Importantly, rhTRX1 treatment decreased ROS generation, activated Wnt/β-catenin signal pathway and considerably promoted the alveolar bone repair of periodontitis mice with diabetes. These findings highlighted the crucial protective role of TRX1 in periodontitis with diabetes and suggested that it may serve as a potential therapeutic target for refractory periodontitis associated with oxidative stress.
Project description:Gene expressions relate to the pathogenesis of periodontitis and have a crucial role in local tissue destruction and susceptibility to the disease. The aims of the present study were to explore comprehensive gene expressions/transcriptomes in periodontitis-affected gingival tissues, and to identify specific biological processes. The purpose of the present study was 1) to compare comprehensive gene expression/transcriptomes of periodontitis-affected gingival tissues with those of healthy tissues by using microarray and data mining technologies, and 2) to analyze significantly differentially expressed genes which belong to pathological pathways in periodontitis by qRT-PCR. Two distinct gingival samples including healthy and periodontal-affected gingiva were taken from 3 patients with severe chronic periodontitis. Total RNAs from 6 gingival tissue samples were used for microarray and data-mining analyses. Comparisons, gene ontology, and pathway frequency analyses were performed and identified significant biological pathways in periodontitis. Quantitative reverse transcription real-time polymerase chain reaction (qRT-PCR) analyse using 14 chronic periodontitis patients including 3 patients listed above and 14 healthy individuals showed 9 differentially expressed genes in leukocyte migration and cell communication pathways.
Project description:Periodontitis, delineated by the destruction of structures that support teeth, is predominantly propelled by intricate immune responses. Immunomodulatory treatments offer considerable promise for the management of this ailment; however, the modulation of the periodontal immune microenvironment to facilitate tissue regeneration presents a substantial biomedical challenge. Herein, our study investigates the role of Wilms' tumor 1-associating protein (WTAP), a critical m6A methyltransferase, in the immunomodulation of periodontitis and assesses its viability as a therapeutic target. We observed heightened expression of WTAP in macrophages extracted from gingival tissues impacted by periodontitis, with a strong association with M1 polarization. Via loss-of-function experiments, we demonstrated that diminishing WTAP expression precipitates a transition from M1 to M2 macrophage phenotypes amidst inflammatory conditions, thus improving the periodontal immune landscape. Further, RNA sequencing and indirect co-culture assays indicated that suppressing of WTAP expression modulates osteoimmune responses and enhances the osteogenic differentiation of bone marrow stromal cells. The local deployment of adeno-associated virus-shWTAP in murine models of periodontitis robustly validated the therapeutic promise of targeting WTAP in this disease. Collectively, our findings highlight the crucial role of WTAP in orchestrating macrophage-mediated osteoimmune responses and tissue regeneration in periodontitis, proposing novel avenues for immunotherapeutic interventions in its treatment.
Project description:Expression profiling by microarray was performed to delineate the EBV effect on the transcriptome of gingival tissues from periodontitis patients and healthy volunteers. The transcriptome analysis revealed numerous genes that were differentially expressed in periodontitis only when EBV was present. The most upregulated genes were related to inflammatory/immune response, B and plasma cell markers. Conversely, major downregulation was reported for genes related to epithelial tissue organization and structural support. The results provide new significant insights regarding EBV physiopathology in the gum, assigning a direct etiopathogenetic contribution to EBV in periodontitis.