Identification and characterization of a chymotrypsin-like serine protease from periodontal pathogen, Tannerella forsythia

Innovative strategies targeting oral microbial dysbiosis: unraveling mechanisms and advancing therapies for periodontitis

Periodontitis, a prevalent inflammatory oral disease, is intricately linked to disruptions in the oral microbiome, a state known as microbial dysbiosis. This review explores the pivotal roles of key pathogens, including Porphyromonas gingivalis and Tannerella forsythia, in driving periodontitis and examines the underlying molecular mechanisms that disrupt microbial homeostasis. We discuss how interactions among bacterial species affect the oral ecosystem's balance and how microbial metabolites influence the host immune responses, contributing to disease progression. Leveraging these insights, we propose cutting-edge therapeutic approaches aimed at restoring microbial equilibrium. These include personalized pharmacological interventions tailored to individual microbiome profiles and innovative microbiome-targeted strategies such as probiotic formulations and bacteriophage therapy. By precisely modulating microbial communities, these strategies hold promise for enhancing treatment efficacy, preventing disease recurrence, and mitigating issues like antimicrobial resistance. Overall, this review paves the way for novel prevention and management techniques in periodontitis, offering significant improvements in oral health outcomes for patients.

Outer Membrane Vesicles Derived From Fusobacterium nucleatum Trigger Periodontitis Through Host Overimmunity

The virulent bacteria-induced host immune response dominates the occurrence and progression of periodontal diseases because of the roles of individual virulence factors from these pathogens in the initiation and spread of inflammation. Outer membrane vesicles (OMVs) as a pathogenic entity have recently attracted great attention as messenger bridges between bacteria and host tissues. Herein, the novel role of OMVs derived from Fusobacterium nucleatum in the occurrence of periodontitis is dissected. In a rat periodontitis model, it is found that OMVs derived from F. nucleatum caused deterioration of periodontitis by enhancing inflammation of the periodontium and absorption of alveolar bone, which is almost equivalent to the effect of F. nucleatum itself. Furthermore, that OMVs can independently induce periodontitis is shown. The pathogenicity of OMVs is attributed to multiple pathogenic components identified by omics. After entering human periodontal ligament stem cells (hPDLSCs) by endocytosis, OMVs activated NLRP3 inflammasomes and impaired the mineralization of hPDLSCs through NF-κB (p65) signaling, leading to the final injury of the periodontium and damage of alveolar bone in periodontitis. These results provide a new understanding of OMVs derived from pathogens and cues for the prevention of periodontitis.

Diabetes mellitus promotes susceptibility to periodontitis-novel insight into the molecular mechanisms

Diabetes mellitus is a main risk factor for periodontitis, but until now, the underlying molecular mechanisms remain unclear. Diabetes can increase the pathogenicity of the periodontal microbiota and the inflammatory/host immune response of the periodontium. Hyperglycemia induces reactive oxygen species (ROS) production and enhances oxidative stress (OS), exacerbating periodontal tissue destruction. Furthermore, the alveolar bone resorption damage and the epigenetic changes in periodontal tissue induced by diabetes may also contribute to periodontitis. We will review the latest clinical data on the evidence of diabetes promoting the susceptibility of periodontitis from epidemiological, molecular mechanistic, and potential therapeutic targets and discuss the possible molecular mechanistic targets, focusing in particular on novel data on inflammatory/host immune response and OS. Understanding the intertwined pathogenesis of diabetes mellitus and periodontitis can explain the cross-interference between endocrine metabolic and inflammatory diseases better, provide a theoretical basis for new systemic holistic treatment, and promote interprofessional collaboration between endocrine physicians and dentists.

Periodontitis and diabetes mellitus co-morbidity: A molecular dialogue

BACKGROUND

Type 2 diabetes mellitus (T2DM) and periodontitis are two biologically linked diseases that often coexist in complex interaction. While periodontitis may lead to insulin receptor desensitization, diabetes may increase the expression of inflammatory cytokines, such as Tumor Necrosis Factor-α (TNF-α) and Interleukin 6 (IL-6), in the gingival crevicular fluid and activate osteoclasts via Receptor activator of nuclear factor kappa-Β ligand (RANK-L) production, leading to bone resorption. However, the association between the two diseases processes, where one may exacerbate the progression of the other, is unclear. In addition, both diseases have similar mechanistic themes, such as chronic inflammation and oxidative stress. This review aimed to investigate the pathophysiological and molecular mechanisms underlying T2DM and periodontitis.

HIGHLIGHT

Uncontrolled diabetes is often associated with severe periodontitis, measured by clinical attachment loss. Alteration in the oral microbiome composition, which may activate the host inflammatory response and lead to irreversible oxidative stress, is a common finding in both diseases. An understanding of the molecular crosstalk between the two disease processes is crucial for developing therapeutic targets that inhibit bone resorption and halt the progression of periodontitis in patients with diabetes.

CONCLUSION

The Oral microbiome composition in T2DM and periodontitis shifts toward dysbiosis, favoring bacterial pathogens, such as Fusobacteria and Porphyromonas species. Both conditions are marked by pro-inflammatory immune activity via the activation of Interleukin 17 (IL-17), Interleukin 1 (IL-1), TNF-α, and Nuclear Factor Kappa Beta (NF-κB). Common molecular crosstalk signaling appears to involve advanced glycation end products (AGEs) and oxidative stress. Thus, future drug targets are multifactorial, ranging from modulatory of host inflammatory response to preventing the accumulation of AGEs and oxidative free radicals.

Lingonberries-General and Oral Effects on the Microbiome and Inflammation

Lingonberry (Vaccinium vitis ideae L.) is a low-bush wild plant found in the northern hemisphere. The berries are used in traditional medicine in Finland to treat oral yeast infections. General and oral effects of lingonberries on the microbiome and inflammation are reviewed. A brief introduction to oral microbiome symbiosis and dysbiosis, innate and adaptive immunity and inflammation are included, and special features in microbe/host interactions in the oral environment are considered. In vitro anticancer, antimicrobial, antioxidant, anti-inflammatory, and in vivo mouse and human studies are included, focusing on the symbiotic effect of lingonberries on oral and general health.

The contribution of Tannerella forsythia dipeptidyl aminopeptidase IV in the breakdown of collagen

In this study, we characterized a serine protease from Tannerella forsythia that degrades gelatin, type I, and III collagen. Tannerella forsythia is associated with periodontitis progression and severity. The primary goal of this research was to understand the mechanisms by which T. forsythia contributes to periodontitis progression. One of our previous metatranscriptomic analysis revealed that during periodontitis progression T. forsythia highly expressed the bfor_1659 ORF. The N-terminal end is homologous to dipeptidyl aminopeptidase IV (DPP IV). DPP IV is a serine protease that cleaves X-Pro or X-Ala dipeptide from the N-terminal end of proteins. Collagen type I is rich in X-Pro and X-Ala sequences, and it is the primary constituent of the periodontium. This work assessed the collagenolytic and gelatinolytic properties of BFOR_1659. To that end, the complete BFOR_1659 and its domains were purified as His-tagged recombinant proteins, and their collagenolytic activity was tested on collagen-like substrates, collagen type I and III combined, and on the extracellular matrix (ECM) formed on human gingival fibroblasts culture HGF-1. BFOR_1659 was only found in T. forsythia supernatants, highlighting its potential role on the pathogenicity of T. forsythia. We also found that BFOR_1659 efficiently degrades all tested substrates but the individual domains were inactive. Given that BFOR_1659 is highly expressed in the periodontal pocket, its clinical relevance is suggested to periodontitis progression.