Periodontal disease (PD) is a common dental disease associated with the interaction between dysbiotic oral microbiota and host immunity. It is a prevalent disease, resulting in loss of gingival tissue, periodontal ligament, cementum and alveolar bone. PD is a major form of tooth loss in the adult population. Experimental animal models have enabled the study of PD pathogenesis and are used to test new therapeutic approaches for treating the disease. The ligature-induced periodontitis model has several advantages as compared with other models, including rapid disease induction, predictable bone loss and the capacity to study periodontal tissue and alveolar bone regeneration because the model is established within the periodontal apparatus. Although mice are the most convenient and versatile animal models used in research, ligature-induced periodontitis has been more frequently used in large animals. This is mostly due to the technical challenges involved in consistently placing ligatures around murine teeth. To reduce the technical challenge associated with the traditional ligature model, we previously developed a simplified method to easily install a bacterially retentive ligature between two molars for inducing periodontitis. In this protocol, we provide detailed instructions for placement of the ligature and demonstrate how the model can be used to evaluate gingival tissue inflammation and alveolar bone loss over a period of 18 d after ligature placement. This model can also be used on germ-free mice to investigate the role of human oral bacteria in periodontitis in vivo. In conclusion, this protocol enables the mechanistic study of the pathogenesis of periodontitis in vivo.

An increased population of CD4+CD25highFoxp3+ regulatory T cells (Tregs) in the tumor-associated microenvironment plays an important role in cancer immune evasion. However, the underlying mechanism remains unclear. Here we observed an increased secretion of miR-214 in various types of human cancers and mouse tumor models. Tumor-secreted miR-214 was sufficiently delivered into recipient T cells by microvesicles (MVs). In targeted mouse peripheral CD4+ T cells, tumor-derived miR-214 efficiently downregulated phosphatase and tensin homolog (PTEN) and promoted Treg expansion. The miR-214-induced Tregs secreted higher levels of IL-10 and promoted tumor growth in nude mice. Furthermore, in vivo studies indicated that Treg expansion mediated by cancer cell-secreted miR-214 resulted in enhanced immune suppression and tumor implantation/growth in mice. The MV delivery of anti-miR-214 antisense oligonucleotides (ASOs) into mice implanted with tumors blocked Treg expansion and tumor growth. Our study reveals a novel mechanism through which cancer cell actively manipulates immune response via promoting Treg expansion.

Non-surgical periodontal treatment can effectively improve periodontal and circulating inflammatory status. Despite a lack of strong evidence, trends in some results support improved glycemic control after periodontal treatment in patients with diabetes.

Phosphofructokinase 1 (PFK1) plays a critical role in glycolysis; however, its role and regulation in tumorigenesis are not well understood. Here, we demonstrate that PFK1 platelet isoform (PFKP) is the predominant PFK1 isoform in human glioblastoma cells and its expression correlates with total PFK activity. We show that PFKP is overexpressed in human glioblastoma specimens due to an increased stability, which is induced by AKT activation resulting from phosphatase and tensin homologue (PTEN) loss and EGFR-dependent PI3K activation. AKT binds to and phosphorylates PFKP at S386, and this phosphorylation inhibits the binding of TRIM21 E3 ligase to PFKP and the subsequent TRIM21-mediated polyubiquitylation and degradation of PFKP. PFKP S386 phosphorylation increases PFKP expression and promotes aerobic glycolysis, cell proliferation, and brain tumor growth. In addition, S386 phosphorylation in human glioblastoma specimens positively correlates with PFKP expression, AKT S473 phosphorylation, and poor prognosis. These findings underscore the potential role and regulation of PFKP in human glioblastoma development.