Silencing matrix metalloproteinase-13 (Mmp-13) reduces inflammatory bone resorption associated with LPS-induced periodontal disease in vivo

Local Application of a New Chalconic Derivative (Chalcone T4) Reduces Inflammation and Oxidative Stress in a Periodontitis Model in Rats

Chalcones are phenolic compounds with biological properties. This study had the aim to evaluate the effects of topical administration of a new synthetic chalcone, Chalcone T4, in an animal model of periodontitis induced by ligature. Forty rats were distributed in the following experimental groups: negative control (without periodontitis and topical application of distilled water), positive control (periodontitis and topical application of distilled water), chalcone I and II (periodontitis and topical application of 0.6 mg/mL and 1.8 mg/mL, respectively). Chalcone or distilled water was administered into the gingival sulcus of the first molars daily for 10 days, starting with the ligature installation. The following outcomes were evaluated: alveolar bone loss (µCT and methylene blue dye staining), quantification of osteoclasts (histomorphometry), cell infiltrate and collagen content (stereometry), gene expression of mediators (Nfact11, Tnf-α, Mmp-13, iNos, Sod and Nrf2) by (RT-qPCR); expression of BCL-2 and Caspase-1 (immunohistochemistry). Chalcone T4 inhibited bone resorption and prevented collagen matrix degradation. Reduction in the expression of inflammatory markers (Nfact11, Tnf-α, Mmp-13, and Caspase-1), attenuation of oxidative stress (iNOS reduction, and increase in Sod), and pro-apoptotic effect of the compound (BCL-2 reduction), were associated its effects on periodontal tissues. Topical application of Chalcone T4 prevented bone resorption and inflammation, demonstrating potential in the adjunctive treatment of periodontitis.

An Introductory Guide to Protease Sensitive Linker Design Using Matrix Metalloproteinase 13 as an Example

Proteases play a crucial role, not only in physiological, but also in pathological processes, such as cancer, inflammation, arthritis, Alzheimer's, and infections, to name but a few. Their ability to cleave peptides can be harnessed for a broad range of biotechnological purposes. To do this efficiently, it is essential to find an amino acid sequence that meets the necessary requirements, including interdependent factors like specificity, selectivity, cleavage kinetics, or synthetic accessibility. Cleavage sequences from natural substrates of the protease may not be optimal in terms of specificity and selectivity, which is why these frequently require arduous and sometimes unsuccessful optimization such as by iterative exchange of single amino acids. Hence, here we describe the systematic design of protease sensitive linkers (PSLs)─peptide sequences specifically cleaved by a target protease─guided by the mass spectrometry based determination of target protease specific cleavage sites from a proteome-based peptide library. It includes a procedure for identifying bespoke PSL sequences, their optimization, synthesis, and validation and introduces a program that can indicate potential cleavage sites by hundreds of enzymes in any arbitrary amino acid sequence. Thereby, we provide an introduction to PSL design, illustrated by the example of matrix metalloproteinase 13 (MMP13). This introduction can serve as a guide and help to greatly accelerate the development and use of protease-sensitive linkers in diverse applications.

The protective role of CD73 in periodontitis: preventing hyper-inflammatory fibroblasts and driving osteoclast energy metabolism

Introduction

Periodontitis is an immune-mediated inflammatory disease affecting almost half of the adult population and is the leading cause of tooth loss in the United States. The role of extracellular nucleotide signaling including nucleotide metabolizing enzyme CD73 adds an important layer of interaction of purine mediators capable of orchestrating inflammatory outcomes. CD73 is able to catabolize 5'-adenosine monophosphate into adenosine at the extracellular level, playing a critical role in regulating many processes under physiological and pathological conditions. Here, we explored the role of CD73 in ligature-induced periodontitis in vivo comparing wild-type C57Bl/6J and CD73-deficient mice.

Methods

We assessed gingival levels of inflammatory cytokines in vivo and in murine gingival fibroblasts in vitro, as well as bone loss, and RANKL-induced osteoclastogenesis. We have also analyzed CD73 mRNA in samples derived from patients diagnosed with severe periodontitis.

Results

Our results in mice show that lack of CD73 resulted in increased inflammatory cytokines and chemokines such as IL-1β, IL-17, Cxcl1 and Cxcl2 in diseased gingiva relative to the healthy-controls and in comparison with the wild type. CD73-deficient gingival fibroblasts also manifested a defective healing response with higher MMP-13 levels. CD73-deficient animals also showed increased osteoclastogenesis in vitro with increased mitochondrial metabolism typified by excessive activation of oxidative phosphorylation, increased mitochondrial membrane potential and accumulation of hydrogen peroxide. Micro-CT analysis revealed that lack of CD73 resulted in decreased bone mineral density, decreased trabecular bone volume and thickness as well as decreased bone volume in long bones. CD73 deficiency also resulted in increased alveolar bone loss in experimental periodontitis. Correlative studies of gingival samples from severe (Grade C) periodontitis showed decreased levels of CD73 compared to healthy controls, further supporting the relevance of our murine results.

Conclusion

In conclusion, CD73 appears to play a protective role in the gingival periodontal tissue and bone homeostasis, regulating hyper-inflammatory state of stromal fibroblasts and osteoclast energy metabolism and being an important candidate for future target therapies to prevent or control immune-mediated inflammatory and osteolytic diseases.

Increased expression of angiopoietin-like protein 4 regulates matrix metalloproteinase-13 expression in Porphyromonas gingivalis lipopolysaccharides-stimulated gingival fibroblasts and ligature-induced experimental periodontitis

BACKGROUND

Angiopoietin-like protein 4 (ANGPTL4) is produced in chronic or acute inflammation. Although ANGPTL4 increases in the periodontal ligament fibroblasts during hypoxia, the involvement and role of ANGPTL4 in periodontitis have not been elucidated.

OBJECTIVE

In this study, we investigated whether ligature-induced experimental periodontitis and/or Porphyromonas gingivalis lipopolysaccharides (Pg-LPS) would upregulate ANGPTL4 expression and whether ANGPTL4 would somehow involve in the expression of matrix metalloproteinases (MMPs) which are key molecules in the process of periodontal tissue destruction.

METHODS

Experimental periodontitis was induced in 6-week-old male Sprague-Dawley rats by placing a nylon suture around the neck of the maxillary second molar. Two weeks after the induction of periodontitis, the periodontal tissue was excised and analyzed by histological/immunohistochemical staining and gene expression analyses. Human gingival fibroblasts (hGFs) were stimulated with Pg-LPS. The gene expression of ANGPTLs and receptors involved in ANGPTL4 recognition were observed. We also confirmed the changes in gene expression of MMPs upon stimulation with human ANGPTL4. Furthermore, we downregulated ANGPTL4 expression by short interfering RNA in hGFs and investigated the effect of Pg-LPS on MMP production.

RESULTS

Induction of periodontitis significantly increased the expression of ANGPTL4 in the gingiva. Pg-LPS significantly increased the gene and protein expression of ANGPTL4 in hGFs but not the gene expression of other ANGPTLs or ANGPTL receptors. Recombinant human ANGPTL4 significantly increased MMP13 gene expression in hGFs. We also confirmed that MMP13 expression was increased in the gingiva during experimental periodontitis. Pg-LPS induced MMP13 gene expression in hGFs. These results suggest the pivotal role of ANGPTL4 in periodontitis.

CONCLUSION

Periodontitis increases ANGPTL4 expression in the gingiva, further suggesting that increased ANGPTL4 may be a factor involved in enhancing MMP13 expression.

The Role of Matrix Metalloproteinase in Inflammation with a Focus on Infectious Diseases

Matrix metalloproteinases (MMPs) are involved in extracellular matrix remodeling through the degradation of extracellular matrix components and are also involved in the inflammatory response by regulating the pro-inflammatory cytokines TNF-α and IL-1β. Dysregulation in the inflammatory response and changes in the extracellular matrix by MMPs are related to the development of various diseases including lung and cardiovascular diseases. Therefore, numerous studies have been conducted to understand the role of MMPs in disease pathogenesis. MMPs are involved in the pathogenesis of infectious diseases through a dysregulation of the activity and expression of MMPs. In this review, we discuss the role of MMPs in infectious diseases and inflammatory responses. Furthermore, we present the potential of MMPs as therapeutic targets in infectious diseases.

Assessment of Changes in the Oral Microbiome That Occur in Dogs with Periodontal Disease

The oral microbiome in dogs is a complex community. Under some circumstances, it contributes to periodontal disease, a prevalent inflammatory disease characterized by a complex interaction between oral microbes and the immune system. Porphyromonas and Tannerella spp. are usually dominant in this disease. How the oral microbiome community is altered in periodontal disease, especially sub-dominant microbial populations is unclear. Moreover, how microbiome functions are altered in this disease has not been studied. In this study, we compared the composition and the predicted functions of the microbiome of the cavity of healthy dogs to those with from periodontal disease. The microbiome of both groups clustered separately, indicating important differences. Periodontal disease resulted in a significant increase in Bacteroidetes and reductions in Actinobacteria and Proteobacteria. Porphyromonas abundance increased 2.7 times in periodontal disease, accompanied by increases in Bacteroides and Fusobacterium. It was predicted that aerobic respiratory processes are decreased in periodontal disease. Enrichment in fermentative processes and anaerobic glycolysis were suggestive of an anaerobic environment, also characterized by higher lipopolysaccharide biosynthesis. This study contributes to a better understanding of how periodontal disease modifies the oral microbiome and makes a prediction of the metabolic pathways that contribute to the inflammatory process observed in periodontal disease.

Diagnostic potential and future directions of matrix metalloproteinases as biomarkers in gingival crevicular fluid of oral and systemic diseases

Gingival crevicular fluid (GCF) is a physiological fluid and an inflammatory serum exudate derived from the gingival plexus of blood vessels and mixed with host tissues and subgingival plaque flows. In addition to proteins, GCF contains a diverse population of cells, including desquamated epithelial cells, cytokines, electrolytes, and bacteria from adjacent plaques. Recently, matrix metalloproteinases(MMPs), which are endopeptidases that are active against extracellular macromolecules, in GCF have been revealed as potential utility biomarkers for the diagnosis and follow-up of oral and systemic diseases, thereby facilitating the early evaluation of malignancy risk and the monitoring of disease progression and treatment response. Tissue inhibitors of metalloproteinases (TIMPs) are specific inhibitors of matrixins that participate in the regulation of local activities of MMPs in tissues. This review provides an overview of the latest findings on the diagnostic and prognostic values of MMPs and TIMPs in GCF of oral and systemic diseases, including periodontal disease, pulpitis, peri-implantitis and cardiovascular disease as well as the extraction, detection and analytical methods for GCF.

Natural Killer-Like B Cells Secreting Interleukin-18 Induces a Proinflammatory Response in Periodontitis

Natural killer-like B (NKB) cells, which are newly identified immune subsets, reveal a critical immunoregulatory property in the eradication of microbial infection via the secretion of interleukin (IL)-18. For the first time, this study investigated the role of NKB cells in secreting IL-18 in the pathogenesis of periodontitis. In this study, NKB cells' percentage and IL-18 concentration in peripheral blood and periodontium in periodontitis patients was measured using flow cytometry and ELISA. The role of IL-18 in regulating periodontal inflammation was examined in a Porphyromonas gingivalis (P. gingivalis)-induced periodontitis murine model. Peripheral and periodontal-infiltrating CD3^-CD19⁺NKp46⁺ NKB cells, which were the main source of IL-18, were elevated and correlated with attachment loss in periodontitis patients. In vitro IL-18 stimulation promoted proinflammatory cytokine production in periodontal ligament cells. P. gingivalis infection induced elevation of IL-18 receptor in periodontium in a periodontitis murine model. IL-18 neutralization not only suppressed P. gingivalis-induced alveolar bone resorption, but also inhibited recruitment of antigen-non-specific inflammatory cells into the periodontium, probably via dampening expressions of cytokines, chemokines, and matrix metalloproteinases. NKB cells secreting IL-18 appeared to be an important mediator in the inflammatory response following intraoral P. gingivalis infection. These findings might be relevant to the development of immunotherapies for periodontitis.

[The significance of the expression of matrix metalloproteinases in the differential diagnosis of periodontal diseases]

Investigation of features of expression of matrix metalloproteinases (MMPs) is important for both understanding the mechanisms of the pathogenesis of periodontal diseases, and determining the nature of their course in order to choose a correct and timely treatment strategy.

OBJECTIVE

To establish the value of MMPs for the diagnosis and determination of the nature of the course of periodontitis at the stage of disease manifestation, by morphometrically assessing the expression of MMPs in the gingival biopsy material.

MATERIAL AND METHODS

Gingival biopsy specimens from 82 patients with rapidly progressing (n=26), chronic simple (n=18), and chronic complex (n=38) periodontitis were analyzed. Morphometric and statistical analysis of the expression of MMPs was carried out using Aperio ImageScope v. 12.4.0.5043, Statistica 10.0, and MedCalc (p<0.05).

RESULTS

Analysis of the nature of MMP expression in the gingival biopsy material of patients with periodontal diseases showed that MMP2 and MMP13 were approximately equally involved in the development and course of all the studied forms of periodontitis. An increase in the expression of MMP1, MMP8, and MMP14 and a decrease in that of MMP9 are of the greatest importance in the pathogenesis of a rapidly progressing process. The performed ROC analysis confirmed the significance of the parameters of general and stromal expression of MMP1, MMP9, and MMP14, and mainly stromal expression of MMP8 for the differential diagnosis of rapidly progressing periodontitis with chronic forms, including chronic complex periodontitis.

CONCLUSION

The expression indicators of MMR1, MMR8, MMR9, and MMR14 are most informative in determining the course of periodontitis at the stage of disease manifestation and differential diagnosis of rapidly progressing periodontitis with chronic simplex and complex periodontitis.