Gingival crevicular fluid levels of SLIT3 are increased in periodontal disease

Antimicrobial and anti-inflammatory effects of BenTooth: A natural product blend of burdock root, persimmon leaf extracts, and quercetin on periodontal disease

Periodontal disease represents a condition that exhibits substantial global morbidity, and is characterized by the infection and inflammation of the periodontal tissue effectuated by bacterial pathogens. The present study aimed at evaluating the therapeutic efficacy of BenTooth, an edible natural product mixture comprising burdock root extract, persimmon leaf extract and quercetin, against periodontitis both in vitro and in vivo. BenTooth was examined for antimicrobial properties and its impact on cellular responses related to inflammation and bone resorption. Its effects were also assessed in a rat model of ligature-induced periodontitis. BenTooth demonstrated potent antimicrobial activity against P. gingivalis and S. mutans. In RAW264.7 cells, it notably diminished the expression of inducible nitric oxide synthase and cyclooxygenase-2, as well as reduced interleukin-6 and tumor necrosis factor-α levels triggered by P. gingivalis-derived lipopolysaccharide. Furthermore, BenTooth inhibited osteoclastogenesis mediated by the receptor activator of nuclear factor κB ligand. In the rat model, BenTooth consumption mitigated the ligature-induced expansion in distance between the cementoenamel junction and the alveolar bone crest and bolstered the bone volume fraction. These results present BenTooth as a potential therapeutic candidate for the prevention and remediation of periodontal diseases.

Lipoxin A4 levels predict site-specific clinical improvements post scaling and root planing and correlate negatively with periodontal pathogens in severe periodontitis

BACKGROUND

Serving as a stop signal of inflammation, the role of lipoxin A4 (LXA4) in periodontitis remains to be clarified. This study is aimed to examine the changes in LXA4 levels in gingival crevicular fluid (GCF) after scaling and root planing (SRP) and to determine the relationship between LXA4 levels and treatment outcomes and periodontal pathogens in severe periodontitis.

METHODS

A total of 74 GCF samples were collected from 21 severe periodontitis participants at the deepest affected sites. These sites were re-sampled at 1, 3, and 6 months after SRP. Besides, GCF samples were also collected from 25 periodontally healthy participants. Clinical parameters including probing depth (PD) and clinical attachment level (CAL) in periodontitis group were recorded. LXA4 levels and periodontal pathogens in the GCF were analyzed by ELISA and PCR, respectively. Correlations between GCF LXA4 levels and treatment effect and periodontal pathogens were assessed.

RESULTS

LXA4 levels in GCF significantly increased after SRP (p < 0.05), but remained lower than those observed in healthy individuals (p < 0.05). Sites with lower baseline LXA4 concentrations were more likely to experience greater improvements in PD at 6 months post-SRP (area under the curve [AUC] = 0.792), and the improvements were positively correlated with the increase of LXA4 at these sites post-treatment (p < 0.05). Furthermore, more elevated LXA4 levels were observed in sites that became negative for Prevotella intermedia or Tannerella forsythia after SRP.

CONCLUSION

Baseline LXA4 in GCF has the potential to predict the site-specific response of severe periodontal lesions to SRP. The increase of LXA4 levels after treatment was positively correlated with clinical improvements and negatively correlated with the presence of Prevotella intermedia or Tannerella forsythia.

SLIT3-mediated fibroblast signaling: a promising target for antifibrotic therapies

The SLIT family (SLIT1-3) of highly conserved glycoproteins was originally identified as ligands for the Roundabout (ROBO) family of single-pass transmembrane receptors, serving to provide repulsive axon guidance cues in the nervous system. Intriguingly, studies involving SLIT3 mutant mice suggest that SLIT3 might have crucial biological functions outside the neural context. Although these mutant mice display no noticeable neurological abnormalities, they present pronounced connective tissue defects, including congenital central diaphragmatic hernia, membranous ventricular septal defect, and osteopenia. We recently hypothesized that the phenotype observed in SLIT3-deficient mice may be tied to abnormalities in fibrillar collagen-rich connective tissue. Further research by our group indicates that both SLIT3 and its primary receptor, ROBO1, are expressed in fibrillar collagen-producing cells across various nonneural tissues. Global and constitutive SLIT3 deficiency not only reduces the synthesis and content of fibrillar collagen in various organs but also alleviates pressure overload-induced fibrosis in both the left and right ventricles. This review delves into the known phenotypes of SLIT3 mutants and the debated role of SLIT3 in vasculature and bone. Present evidence hints at SLIT3 acting as an autocrine regulator of fibrillar collagen synthesis, suggesting it as a potential antifibrotic treatment. However, the precise pathway and mechanisms through which SLIT3 regulates fibrillar collagen synthesis remain uncertain, presenting an intriguing avenue for future research.

Occlusal Force Maintains Alveolar Bone Homeostasis via Type H Angiogenesis

Physiologically, teeth and periodontal tissues are exposed to occlusal forces throughout their lifetime. Following occlusal unloading, unbalanced bone remodeling manifests as a net alveolar bone (AB) loss. This phenomenon is termed alveolar bone disuse osteoporosis (ABDO), the underlying mechanism of which remains unclear. Type H vessels, a novel capillary subtype tightly coupled with osteogenesis, reportedly have a role in skeletal remodeling; however, their role in ABDO is not well studied. In the present study, we aimed to explore the pathogenesis of and therapies for ABDO. The study revealed that type H endothelium highly positive for CD31 and endomucin was identified in the periodontal ligament (PDL) but rarely in the AB of the mice. In hypofunctional PDL, the density of type H vasculature and coupled osterix+ (OSX+) osteoprogenitors declined significantly. In addition, the angiogenic factor Slit guidance ligand 3 (SLIT3) was downregulated in the disused PDL, and periodontal injection of the recombinant SLIT3 protein partially ameliorated type H vessel dysfunction and AB loss in ABDO mice. With regard to the molecular mechanism, a mechanosensory signaling circuit, PIEZO1/Ca2+/HIF-1α/SLIT3, was validated by applying cyclic compression to 3-dimensional-cultured PDL cells using the Flexcell FX-5000 compression system. In summary, PDL plays a pivotal role in mechanotransduction by translating physical forces into the intracellular signaling axis PIEZO1/Ca2+/HIF-1α/SLIT3, which promotes type H angiogenesis and OSX+ cell-related osteogenensis, thereby contributing to AB homeostasis. Our findings advance the understanding of PDL in AB disorders. Further therapies targeting SLIT3 may provide new insights into preventing bone loss in ABDO.

Immunomodulation in the Treatment of Periodontitis: Progress and Perspectives

Periodontitis is one of the most common dental diseases. Compared with healthy periodontal tissues, the immune microenvironment plays the key role in periodontitis by allowing the invasion of pathogens. It is possible that modulating the immune microenvironment can supplement traditional treatments and may even promote periodontal regeneration by using stem cells, bacteria, etc. New anti-inflammatory therapies can enhance the generation of a viable local immune microenvironment and promote cell homing and tissue formation, thereby achieving higher levels of immune regulation and tissue repair. We screened recent studies to summarize the advances of the immunomodulatory treatments for periodontitis in the aspects of drug therapy, microbial therapy, stem cell therapy, gene therapy and other therapies. In addition, we included the changes of immune cells and cytokines in the immune microenvironment of periodontitis in the section of drug therapy so as to make it clearer how the treatments took effects accordingly. In the future, more research needs to be done to improve immunotherapy methods and understand the risks and long-term efficacy of these methods in periodontitis.