Pathogenesis of periodontitis - A potential role for epithelial-mesenchymal transition

Induction of Epithelial-Mesenchymal Transition in Periodontitis Rat Model

OBJECTIVES

 Epithelial-mesenchymal transition (EMT) is a process that shifts cellular phenotype. It is linked to several different inflammatory diseases including periodontitis. This study was conducted to investigate the involvement of the EMT process in an experimental periodontitis (EP) model.

MATERIALS AND METHODS

 Second upper molars of Wistar albino male rats were ligated to induce periodontitis, while controls were not ligated. The animals were sacrificed after 0, 3, 7, 14, and 21 days (n = 6 for each time point). The maxillae were resected, posterior to the incisor teeth, and the gingival tissue surrounding teeth were analyzed. Alveolar bone loss (ABL), epithelial thickness, and the number of inflammatory cells were measured at each time point. Expressions of EMT-related biomarkers (E-cadherin, N-cadherin, Snail1, Twist1, and vimentin) were assessed using the immunohistochemical technique. All experiments were performed in triplicate.

STATISTICAL ANALYSIS

 Inferential comparisons were performed by the kruskall-wallis test. To determine the correlation between the dependent and independent variables ,Spearman's correlation test was used.

RESULTS

 ABL, epithelial thickness, and inflammatory cell count were gradually increased throughout the EP study period. Switching of E-cadherin/N-cadherin was evident and associated with increased nuclear expression of Snail1 and Twist1. Additionally, positive cytoplasmic expression of vimentin was detected from day 7 and increased at subsequent time points. Histoscore of E-cadherin was negatively and significantly correlated with N-cadherin and Snail1. Furthermore, Snail1 and Twist1 histoscores were significantly and positively correlated.

CONCLUSION

 The results demonstrated induction of an EMT phenotype in the EP model. This was supported by cadherin switching and positive vimentin expression along with nuclear translocation of Snail1 and Twist.

Role of E-cadherin in epithelial barrier dysfunction: implications for bacterial infection, inflammation, and disease pathogenesis

Epithelial barriers serve as critical defense lines against microbial infiltration and maintain tissue homeostasis. E-cadherin, an essential component of adherens junctions, has emerged as a pivotal molecule that secures epithelial homeostasis. Lately, its pleiotropic role beyond barrier function, including its involvement in immune responses, has become more evident. Herein, we delve into the intricate relationship between (dys)regulation of epithelial homeostasis and the versatile functionality of E-cadherin, describing complex mechanisms that underlie barrier integrity and disruption in disease pathogenesis such as bacterial infection and inflammation, among others. Clinical implications of E-cadherin perturbations in host pathophysiology are emphasized; downregulation, proteolytic phenomena, abnormal localization/signaling and aberrant immune reactions are linked with a broad spectrum of pathology beyond infectious diseases. Finally, potential therapeutic interventions that may harness E-cadherin to mitigate barrier-associated tissue damage are explored. Overall, this review highlights the crucial role of E-cadherin in systemic health, offering insights that could pave the way for strategies to reinforce/restore barrier integrity and treat related diseases.

Association of Polymorphism with Periodontitis and Salivary Levels of Hypoxia-Inducible Factor-1α

OBJECTIVE

 This investigation aims to investigate the association between HIF-1α genetic polymorphism and periodontitis and examine and contrast the levels of HIF-1α present in the saliva of subjects afflicted with periodontitis and in the control group. Additionally, this study aims to establish diagnostic proficiency of this biomarker in distinguishing between periodontal health and disease.

MATERIALS AND METHODS

 This study entailed the collection of venous blood samples and unstimulated saliva samples from a total of 160 participants, encompassing 80 individuals diagnosed with periodontitis and 80 periodontitis-free individuals. The periodontal parameters were evaluated, involving the measurement of clinical attachment loss, the probing pocket depth, and the bleeding on probing percentage. Subsequently, genetic analysis of HIF-1α using polymerase chain reaction (PCR) technique, DNA sequencing, and enzyme-linked immunosorbent assays was conducted.

RESULTS

 The genetic analysis of 352 bp of the HIF-1α gene revealed the presence of 66 single-nucleotide polymorphisms (SNPs) in control samples, whereas 78 SNPs were found in periodontitis sample. The nucleotide A was replaced with a C nucleotide at position 207 of the amplified PCR fragments. The homozygous AA pattern was predominant in the control group, with significant differences between the two groups. In contrast, the homozygous CC pattern was more dominant in the periodontitis group, with significant differences between the two groups. The analysis of Hardy-Weinberg equilibrium for the comparison between the observed and the expected genotypes showed significant differences between the observed and the expected values in the control and periodontitis groups, as well as the total sample. The highest mean values of the measured periodontal parameters were found in the periodontitis group (clinical attachment loss = 4.759, probing pocket depth = 4.050, and bleeding on probing = 30.950) with statistically significant differences between the groups. The periodontitis group showed significantly higher salivary HIF-1α levels compared to control group (p < 0.001). Besides, HIF-1α is a good biomarker in distinguishing between periodontal health and periodontitis.

CONCLUSION

 rs1951795 SNP of HIF-1α has no significant impact on the progression of periodontitis and the salivary level HIF-1α. Periodontitis results in a notable elevation in HIF-1α salivary levels, with an outstanding diagnostic ability to distinguish between periodontitis and periodontal health.

Efficacy of Erythritol Air Polishing for Inducing Initial Healing of Shallow-to-Moderate Periodontal Pockets and Restoring Gingival Crevicular Fluid β-Catenin, 8-Hydroxy-Deoxyguanosine and Total Antioxidant Capacity: A Split-Mouth Randomised Clinical Trial

OBJECTIVE

To evaluate the efficacy of subgingival erythritol powder air polishing (EPAP) for inducing initial healing of shallow-to-moderate periodontal pockets and its effect on gingival crevicular fluid (GCF) β-catenin, 8-hydroxy-deoxyguanosine (8-OHdG) and total antioxidant capacity (TAC) levels.

METHODS

This randomised, split-mouth clinical trial involved 22 periodontitis patients. Periodontal pockets (4-6 mm) were treated either by scaling and root planing (control) or EPAP followed by subgingival instrumentation 1 month later (test). Clinical periodontal variables were recorded, and GCF samples were collected from the selected sites at baseline, week 4 and week 12 visits. The GCF levels of β-catenin, 8-OHdG and TAC were estimated via enzyme-linked immunosorbent assay (ELISA).

RESULTS

Compared with those at baseline, both groups showed non-different significant reductions in clinical variables at week 4 and week 12 after treatment. GCF β-catenin and 8-OHdG levels at both the test and control sites significantly decreased at week 4 and continued to further decrease at week 12. A greater reduction in GCF β-catenin was detected at the control sites at the week 12 visit. Conversely, GCF TAC was only significantly increased at week 12 in both groups, but the difference between the groups was not significant.

CONCLUSION

Using of EPAP has the potential to induce initial healing in shallow-to-moderate pockets as it offers non-different changes in clinical outcomes and GCF biomarkers compared to conventional method.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT05798871.

miRNA-199b-5p suppresses of oral squamous cell carcinoma by targeting apical-basolateral polarity via Scribble/Lgl

In epithelial cells, Scribble forms cell-cell junctions and contributes to cell morphology and homeostasis by regulating apical-basolateral polarity in mammals and functions as a tumor suppressor in many carcinomas. The initial diagnosis of oral squamous cell carcinoma is important, and its prognosis is poor when accompanied by metastasis. However, research on the mechanisms of oral squamous cell carcinoma metastasis is insufficient. Herein, we showed that Scribble regulates the apical-basolateral polarity of oral squamous cell carcinoma by regulating lethal giant larvae 1, Scribble module and E-cadherin, the adhesion junction. The expression of lethal giant larvae 1 and E-cadherin decreased when the expression of Scribble was knocked down and their localization was completely disrupted in both the oral squamous cell carcinoma cell line and in vivo model. In particular, the Scribble was involved in oral squamous cell carcinoma metastasis via hsa-miR-199b-5p, which is a microenvironmental factor of hypoxia. The disruption of Scribble localization under hypoxic conditions, but its localization was maintained in miR-199b-5p oral squamous cell carcinoma cell lines and in vivo. These results suggest that Scribble functions as a tumor suppressor marker mediated by miR-199b-5p in oral squamous cell carcinoma.

Salvadora persica leaves: phytochemical profile and in vitro-inhibitory activity on inflammatory mediators implicated in periodontal disease

CONTEXT

Virtually all parts of Salvadora persica L. (Salvadoraceae) are used in traditional medicine. The twigs and leaves are used for oral health, but leaves are far less investigated.

OBJECTIVE

This study assesses the oral health-promoting potential of S. persica leaves with emphasis on anti-inflammatory and antiproliferative effects and provides an in depth-characterization of their metabolite profile.

MATERIALS AND METHODS

Hot-water and methanolic S. persica leaf extracts (1, 10, and 100 µg/mL) and their major constituents (5, 10, and 50 µM), were subjected to cellular assays on IL-8 and TNFα release in LPS-stimulated human neutrophils, NO-release in LPS/IFNγ stimulated mouse macrophages, and proliferation of HNO97 human tongue carcinoma cells. Metabolite profiling was performed by UHPLC-HRMS analysis. Major constituents were isolated and structurally elucidated.

RESULTS AND DISCUSSION

Both extracts showed pronounced anti-inflammatory activity in LPS-stimulated neutrophils. Major identified compound classes were flavonoid glycosides, the glucosinolate glucotropaeolin, phenyl- and benzylglycoside sulfates, and megastigmane glycosylsulfates, the latter ones identified for the first time in S. persica. Glucotropaeolin strongly inhibited the release of IL-8 and TNF-α (13.3 ± 2.0 and 22.7 ± 2.6% of the release of stimulated control cells at 50 µM), while some flavonoids and 3-(3'-O-sulfo-β-d-glucopyranosyloxy)-7,8-dihydro-β-ionone, a newly isolated megastigmane glycosylsulfate, were moderately active. Benzylisothiocyanate, which is likely formed from glucotropaeolin during traditional application of S. persica, showed considerable antiproliferative activity (IC50 in HNO97 cells: 10.19 ± 0.72 µM) besides strongly inhibiting IL-8 and TNFα release.

CONCLUSIONS

Glucotropaeolin and benzylisothiocyanate are likely implicated in the oral health-promoting effects of S. persica leaves. The chemistry and pharmacology of the newly identified megastigmane glycosylsulfates should be further evaluated.

The role of interleukin-20 on inflammatory stress and periodontal tissue destruction in patients with metabolic syndrome and periodontitis

BACKGROUND

There is an increasing occurrence of periodontitis and metabolic syndrome (MetS), which is resulting in a decline in the overall quality of life. Both disorders can occur together since they are both linked to insulin resistance and systemic inflammation. However, evidence for a role of interleukin (IL)-20 in this comorbidity is very limited. This cross-sectional study aimed to comprehensively investigate, for the first time, the levels of RANKL/OPG, MMP-8 and OSI as well as the role of IL-20 in patients with MetS and periodontitis.

METHODS

The study included a total of 80 individuals, divided into four groups: 20 individuals who were healthy both systemically and periodontally, 20 individuals who were systemically healthy but had periodontitis, 20 individuals who had MetS but were periodontally healthy, and 20 individuals who had both MetS and periodontitis. Periodontal clinical parameters (plaque index, gingival index, bleeding on probing, clinical attachment loss, probing pocket depth) were evaluated. Gingival crevicular fluid (GGF) and serum samples were collected and used for biochemical assays. Enzyme-linked immunosorbent assay was used to determine the levels of IL-20, receptor activator of nuclear factor kappa B ligand (RANKL)/osteoprotegerin (OPG), matrix metalloproteinase-8 (MMP-8) and oxidative stress index (OSI).

RESULTS

IL-20 levels measured in serum and GCF were statistically significantly highest in patients with MetS and periodontitis (p = 0.001). Significant positive correlation was observed between serum and GCF IL-20 values and periodontal parameters (p < 0.05). There was a positive correlation between RANKL and RANKL/OPG levels and IL-20 and clinical parameters (p < 0.05). OSI values were found to be increased in the presence of both periodontitis and MetS (p = 0.001) and were positively correlated with serum and GCF IL-20 (p < 0.05).

CONCLUSIONS

These data from the study suggest a correlation between IL-20 and both MetS and periodontitis. IL-20 may potentially worsen the condition of periodontal tissue by increasing both the oxidative stress levels, periodontal collagen degredation and the ratio of RANKL to OPG.

TRIAL REGISTRATION

This study was registered on ClinicTrials.gov (NCT06092853), 2023-10-10, retrospectively registered.

Fusobacterium nucleatum-infected periodontitis promotes renal interstitial fibrosis in rats through the TGF-β/SMAD2/3 and β-catenin signaling pathways

OBJECTIVES

Periodontitis is associated with Fusobacterium nucleatum (F.n) infection. Although the colonization of renal tissue by F.n is well documented, its specific role in kidney disease has yet to be determined. This study aimed to investigate the potential association between F.n-induced periodontitis and renal interstitial fibrosis.

METHODS

The rat gingival sulcus was injected with F.n suspension, while the control group (NC) was injected with PBS. The levels of total protein (TP), albumin (ALB), creatinine, and urea nitrogen (BUN) in rat serum and/or urine were quantified using the appropriate kits. Renal interstitial fibrosis and epithelial-mesenchymal transition (EMT) were evaluated in rats using Masson staining, Periodic Schiff-Methenamine (PASM) staining, and immunohistochemical staining. The levels of fibrosis- and EMT-related proteins and the TGF-β/SMAD2/3 and β-catenin signaling pathways were determined using Western blot analysis. F.n in the kidney tissues was quantitatively determined using bacterial 16S rRNA technology.

RESULTS

Serum levels of TP, ALB, creatinine, and BUN were not significantly decreased in F.n-infected rats with periodontitis. The levels of creatinine and ALB in the urine were not statistically different between two groups. Masson and PASM staining showed that F.n-induced periodontitis could promote renal interstitial fibrosis in rats. The levels of collagen I, fibronectin (FN), vimentin, and α-SMA were upregulated in the kidney tissues of rats with F.n-induced periodontitis and in F.n-treated HK-2 cells. However, E-cadherin levels were reduced. F.n promoted renal interstitial and HK-2 cell fibrosis in rats by modulating the TGF-β/SMAD2/3 and β-catenin signaling pathways. F.n colonization increased renal interstitial fibrosis in rats.

CONCLUSION

F.n-induced periodontitis promoted EMT by activating the TGF-β/SMAD2/3 and β-catenin signaling pathways, thus promoting renal interstitial fibrosis in rats.

Diagnostic Potential of Salivary Interleukin-1β and IL-10 for Distinguishing Periodontal Health From Periodontitis and Stable From Unstable Periodontitis: A Case-Control Study

Objective: This case-control study aimed to investigate the diagnostic accuracy of salivary interleukin (IL)-1β, IL-10, and IL-1β/IL-10 ratio to discriminate periodontitis from periodontal health and stable from unstable periodontitis. Methods: Saliva samples were collected from 135 (healthy on an intact periodontium = 45 [as healthy control], stable periodontitis = 39, and unstable periodontitis = 51) participants, and then clinical periodontal parameters were recorded. An enzyme-linked immunosorbent assay was used to determine salivary levels of IL-1β and IL-10. Area under the curves (AUCs), sensitivity, and specificity of IL-1β, IL-10, and IL-1β/IL-10 were estimated to discriminate between groups. Result: The level of salivary IL-1β was significantly higher in unstable periodontitis than in stable periodontitis and healthy control groups (426 ± 59, 247 ± 55, and 204 ± 36 pg/ml [picograms per milliliter], respectively). While the level of salivary IL-10 was significantly higher in the control group (360.7 ± 80.5 pg/ml) than unstable periodontitis group (146.92 ± 1.8 pg/ml), no significant difference was found between the control and stable periodontitis (317.04 ± 59.8 pg/ml) groups. IL-1β, IL-10, and IL-1β/IL-10 had significant diagnostic accuracy for differentiating healthy control from unstable periodontitis (AUCs = 0.99, 0.96, and 1; sensitivity = 0.98,1, and 1; specificity = 0.95, 0.95, and 1, respectively). Similarly, they showed significant diagnostic accuracy in distinguishing unstable from stable periodontitis (AUCs = 0.98, 0.99, and 1; sensitivity = 0.94, 1, and 1; specificity = 0.94, 0.97, and 1, respectively). Conclusion: Salivary IL-1β, IL-10, and IL-1β/IL-10 have a high potential to discriminate healthy control from periodontitis and stable from unstable periodontitis. Trial Registration: ClinicalTrials.gov identifier: NCT05722613.

E-cadherin and TAC in GCF accurately discriminate periodontal health and disease

OBJECTIVE

To investigate the accuracy of gingival crevicular fluid (GCF) E-cadherin and total antioxidant capacity (TAC) to discriminate periodontal health from disease.

SUBJECTS AND METHODS

GCF samples were collected from participants with periodontal health (control), gingivitis, and periodontitis (n = 25 each group). The latter group was further subdivided according to stage (S) and grade. Periodontal parameters were recorded then levels of biomarkers were assayed using ELISA and antioxidant status by use of the Total Antioxidant Capacity Assay for E-cadherin and TAC, respectively.

RESULTS

All periodontal parameters were significantly higher in periodontally diseased groups than controls. The GCF E-cadherin significantly increased in gingivitis and periodontitis (S2 to S4) cases as compared to controls. Level of this protein in GCF samples from periodontitis S3 was significantly higher than in gingivitis and S2 groups. The GCF-TAC level was significantly higher in controls than in periodontally diseased groups. No significant differences were observed in the levels of these proteins between grade B and C periodontitis. Both molecules could discriminate periodontal health from gingivitis and periodontitis stages and differentiating periodontitis S3 from gingivitis and other periodontitis stages.

CONCLUSIONS

Levels of TAC and unbounded E-cadherin in GCF samples exhibited promising diagnostic abilities to differentiate periodontal health and disease.

The Potential Role of Reactive Oxygen Species Produced by Low-Density Neutrophils in Periodontitis

OBJECTIVE

 Neutrophils own an arsenal of dischargeable chemicals that enable them to handle bacterial challenges, manipulating innate immune response and actual participation in acquired immunity. The reactive oxygen species (ROS) are one of the most important chemicals that neutrophils discharge to eradicate pathogens. Despite their beneficial role, the ROS were strongly correlated to periodontal tissue destruction. Lowdensity neutrophils (LDN) have been recognized for producing enhanced quantities of ROS. However, the potential role of ROS produced by LDN in periodontitis is unknown. The aim of the study was to investigate the impact of ROS produced by LDN in periodontal diseases.

MATERIALS AND METHODS

 Venous blood and periodontal parameters were obtained from 100 systemically healthy subjects divided into 40 participants with healthy periodontium in the control group and 60 with unstable periodontitis in the study group. Flow cytometry was used to measure the production of ROS by LDN in both groups.

STATISTICAL ANALYSIS

 The data were analyzed for normal distribution using the Shapiro-Wilk test at p < 0.05, Spearman's correlations, and Mann-Whitney U test. Statistical analysis was performed in SPSS v25.

RESULTS

 No difference between the groups had been obtained in ROS production by LDN. However, a significant positive correlation existed between ROS and clinical attachment loss in periodontitis.

CONCLUSION

 LDN exhibits the same ROS generation capacity in the control and periodontitis groups.

Accuracy of Gingival Crevicular Fluid Biomarkers of MMP8, TIMP1, RANK, RANKL, and OPG in Differentiating Symptomatic and Asymptomatic Apical Periodontitis

Apical periodontitis (AP) is the most prevalent chronic inflammatory disease of the teeth. Bone resorption dynamics in symptomatic and asymptomatic AP are still unrecognized. This study examined different inflammatory markers within gingival crevicular fluid, including matrix metalloproteinases 8 (MMP8), tissue inhibitors of metalloproteinases 1 (TIMP1), receptor activator of nuclear factor κB (RANK), its ligand (RANKL), and osteoprotegerin (OPG), to be used in comparing symptomatic apical periodontitis (SAP) and asymptomatic apical periodontitis (AAP) versus healthy teeth. Subjects with SAP, AAP, and a control group were recruited and GCF samples were collected by Periopaper strips. Clinical and radiographical measures were used for diagnosing AP. Levels of MMP8, TIMP, RANK, RANKL, and OPG were determined by ELISA and their abilities to discriminate between examined sites were evaluated by receiver operator characteristic (ROC) curves. All examined biomarkers were statistically significant higher (p < 0.05) in SAP than AAP and the control group, apart from RANK. Significant positive correlations (p < 0.05) were identified between all SAP and AAP biomarkers except TIMP1 and RANK in AAP teeth. TIMP1 and OPG exhibited the highest ability to distinguish between SAP and AAP with areas under the curve of 0.824 and 0.763 in comparing SAP and the control group, and 0.732 and 0.73 when comparing AAP and the control group, respectively. Additionally, TIMP1 and OPG showed the highest AUC of 0.778 and 0.747 when SAP and AAP were compared, respectively. This study concluded that GCF levels of TIMP1 and OPG can be used to differentiate between SAP, AAP, and healthy teeth.

Single-cell sequencing, spatial transcriptome ad periodontitis: Rethink pathogenesis and classification

OBJECTIVE

This narrative review illuminates on the application of single-cell RNA sequencing (scRNA-seq) and spatial transcriptomics (ST) in periodontitis and highlights the probability of relating cell population and gene signatures to the pathogenesis of the disease for a better diagnosis.

METHODS

An electronic search of the literature in the PubMed database for the keywords, "single cell sequencing" OR "spatial transcriptomics" and "periodontitis" OR "gingiva" OR "oral mucosa" yielded 486 research articles and reviews. After filtering duplicates and careful curation, 22 papers conducted in humans were retained.

RESULTS

The molecular mechanisms underlying periodontitis are complex and involve the interaction of multiple cells and various gene expressions. Most residing cells in periodontal tissues participate in maintaining homeostasis and health, while in addition to infiltrating immune cells contribute to the fight against the bacterial insult.

CONCLUSION

scRNA-seq and ST have provided new insights into the cellular and molecular changes associated with periodontitis for a better diagnosis and clinical outcome. New functions of cells and genes are revealed with these techniques; however, no cells or gene signatures are attributed to periodontitis so far.

The effect of interleukin-20 on periodontal tissue destruction in individuals with periodontitis

BACKGROUND AND OBJECTIVE

Periodontitis is an inflammatory disease that destroys periodontal tissues. Interleukin-20 (IL-20), on the other hand, is known as a potent angiogenic, chemotactic, and pro-inflammatory cytokine associated with various chronic inflammatory disorders. IL-20 has a significant role in the regulation of osteoclastogenesis and osteoblastogenesis. This study aimed to evaluate the effect of IL-20 on periodontal destruction.

METHODS

In this study, a total of 60 participants were included, 30 of whom were systemically and periodontally healthy (control group), and 30 were systemically healthy but had periodontitis (periodontitis group). Gingival crevicular fluid (GCF) and serum samples were collected from the participants for biochemical analysis. Enzyme-linked immunosorbent assay was used to determine the levels of IL-20, tumor necrosis factor (TNF)-α, IL1β/IL-10, RANKL/osteoprotegerin (OPG), and matrix metalloproteinase-8 (MMP8). For statistical analysis, the independent t-test, Pearson correlation coefficients, and the Chi-square test were used.

RESULTS

GCF IL-20, RANKL, RANKL/OPG, serum IL-20, RANKL, RANKL/OPG, MMP-8, TNF-α, IL-1B, and IL-1β/IL-10 values were found to be statistically significantly higher in the periodontitis group than in the control group. GCF OPG and serum IL-10 values were found to be statistically significantly higher in the control group than in the periodontitis group. No statistically significant difference was observed between the groups in serum OPG values. A statistically significantly positive correlation was observed between serum IL-20 value and serum RANKL, RANKL/OPG, MMP-8, TNF-α, IL-1β values, and periodontal clinical parameters. The ROC curves showed: AUC = 0.788 for GCF IL-20, and AUC = 1.000 for serum IL-20.

CONCLUSION

According to the results of the study, IL-20 was found to be associated with periodontitis. The role of IL-20 in periodontal pathogenesis is related to osteoclastogenesis and collagen degradation. It is conceivable that IL-20 may increase bone destruction by both affecting the RANKL/OPG ratio and proinflammatory cytokines.

Cell Junctions in Periodontal Health and Disease: An Insight

Cells are the building blocks of all living organisms. The presence of cell junctions such as tight junctions, gap junctions, and anchoring junctions between cells play a role in cell-to-cell communication in periodontal health and disease. A literature search was done in Scopus, PubMed, and Web of Science to gather information about the effect of cell junctions on periodontal health and disease. The presence of tight junction in the oral cavity helps in cell-to-cell adhesiveness and assists in the barrier function. The gap junctions help in controlling growth and development and in the cell signaling process. The presence of desmosomes and hemidesmosomes as anchoring junctions aid in mechanical strength and tissue integrity. Periodontitis is a biofilm-induced disease leading to the destruction of the supporting structures of the tooth. The structures of the periodontium possess multiple cell junctions that play a significant role in periodontal health and disease as well as periodontal tissue healing. This review article provides an insight into the role of cell junctions in periodontal disease and health, and offers concepts for development of therapeutic strategies through manipulation of cell junctions.

Ability of gingival crevicular fluid volume, E-cadherin, and total antioxidant capacity levels for predicting outcomes of nonsurgical periodontal therapy for periodontitis patients

OBJECTIVES

To determine the potential of gingival crevicular fluid (GCF) volume, E-cadherin and total antioxidant capacity (TAC) levels to predict the outcomes of nonsurgical periodontal therapy (NSPT) for periodontitis patients.

BACKGROUND

NSPT is the gold-standard treatment for periodontal pockets < 6 mm in depth, however, successful outcomes are not always guaranteed due to several factors. Periodontitis-associated tissue destruction is evidenced by the increased level of soluble E-cadherin and reduced antioxidants in oral fluids which could be used as predictors for success/failure of NSPT.

MATERIALS AND METHODS

Patients with periodontitis (n = 24) were included in this clinical trial and full-mouth periodontal charting was recorded for each patient. GCF samples from periodontal pockets with probing pocket depth (PPD) 4-6 mm from the interproximal surfaces of anterior and premolar teeth were obtained. These sites subsequently received NSPT and were clinically re-evaluated after 1 and 3 months. Levels of GCF E-cadherin and TAC levels were assayed using ELISA.

RESULTS

All clinical periodontal parameters were significantly improved 3 months after completion of NSPT. These outcomes were associated with a significant decrease in E-cadherin levels and GCF volume, while TAC levels were significantly increased in samples obtained in follow-up appointments. Binary regression model analysis showed that PPD, GCF volume, E-cadherin, and TAC levels could significantly (p < .05) predict the outcomes of NSPT. The cut-off points for PPD, GCF volume, E-cadherin and TAC were 5 mm, 4 × 10-3, 1267.97 pg/mL and 0.09 μmol/g, respectively.

CONCLUSION

NSPT improved clinical parameters along with increased antioxidants capacity and epithelial pocket lining integrity. Discrimination of favorable/unfavorable responsiveness of periodontally diseased sites to NSPT could be possible by using GCF volume, PPD, E-cadherin and TAC level assessments.

PYCARD gene polymorphisms and susceptibility to periodontal and coronary heart diseases

Numerous studies have established a link between gene variants within the inflammasome complex and the incidence of periodontitis and cardiovascular illness across various ethnic groups. This study investigated the association between PYCARD gene polymorphism and susceptibility to periodontal disease and coronary heart disease (CHD) and their correlation with clinical periodontal indices. A total of 120 participants were enrolled, categorized into four groups: 30 healthy controls (C), 30 patients with generalized periodontitis (P), 30 patients with atherosclerotic CHD but clinically healthy periodontium (AS-C), and 30 patients with both atherosclerotic CHD and generalized periodontitis (AS-P). We recorded demographic data, collected blood samples, and measured periodontal indices, including plaque index, clinical attachment loss, bleeding on probing, and pocket depth. The genomic variant of the PYCARD gene was analyzed using a conventional polymerase reaction. A significant prevalence of T and G allele mutations and a higher distribution of CT and TT genotypes in PYCARD C/T (rs8056505) and the AG genotype in PYCARD A/G (rs372507365) were observed in groups P, AS-P, and AS-C. These single nucleotide polymorphisms (SNPs) were also positively correlated with the severity of clinical periodontitis indices. Our findings suggest that the increased frequency of T and G alleles and the distribution of CT, TT, and AG genotypes in PYCARD SNPs are significantly associated with an elevated risk for periodontal disease and CHD. These SNPs may participate in the pathogenesis of these conditions. The study reinforces the potential role of these genetic markers as risk factors for both diseases in the Iraqi population.

Does crocin create new hope for the treatment of oral problems? A focus on periodontitis

According to the World Health Organization (WHO) reports, oral health has an indispensable role in the maintenance of human public health. However, oral problems, especially periodontitis, are known as bad players in this issue. Periodontitis, as the most prevalent oral disease, is a type of chronic illness mediated by bacterial pathogens and immune system reactions, which is linked with the destruction of tooth-protecting tissues, such as alveolar bone and periodontal ligament. Periodontitis has a high prevalence (over 40% in the United States) and can be associated with other systemic ailments, for instance, arthritis, osteoporosis, metabolic syndrome, cancer, respiratory diseases, chronic kidney disease, and Alzheimer's disease. The common treatments for periodontitis are classified into invasive (surgical) and noninvasive (antibiotic therapy, scaling, and root planning) methods; however, these therapies have not reflected enough effectiveness for related patients. New documents inform the beneficial effects of plant-based compounds in healing various disorders, like periodontitis. In conjunction with this subject, it has been revealed that crocin, as an active component of saffron, regulates the balance between osteoclasts and osteoblasts and has a stroking role in the accumulation of the most common collagen in teeth and bone (type 1 collagen). Besides, this carotenoid compound possesses anti-inflammatory and anti-oxidative effects, which can be associated with the therapeutic processes of crocin in this oral disease. Hence, this narrative review study was performed to reflect the reparative/regenerative aspects of crocin agonist periodontitis.

Pan-cancer analysis reveals the prognostic gene CASR suppresses tumor progression and epithelial-mesenchymal transition in renal clear cell carcinoma

Calcium-sensing receptor (CASR), primarily found in the parathyroid gland and other tissues, plays a crucial role in sensing and regulating extracellular calcium, which was also aberrantly expressed in human tumors. Nevertheless, a comprehensive analysis of CASR in pan-cancer has yet to be conducted. To gain a better understanding of CASR in pan-cancer, data profiles on CASR cancers were collected from TCGA database. The expression level, clinical significance, prognostic value, and potential mechanisms of CASR in pan-cancer were analyzed via multiple public databases. The functional assays were conducted using human kidney renal clear cell carcinoma (KIRC) cell lines, clinical samples, and nude mice. Our research revealed that the abnormal expression of CASR was found in a variety of tumors. The expression and mutation of CASR were significantly associated with tumor prognosis and stage. Pathway analyses suggested that CASR was involved in the epithelial-mesenchymal transition (EMT) progress. Besides, CASR expression was correlated with immune inhibitory genes and immunotherapy in cancers. Particularly in KIRC, we established that CASR mRNA and protein levels were downregulated in clinical samples and cell lines. Moreover, a Cox regression analysis revealed that CASR was an independent prognostic factor in both TCGA-KIRC samples and clinical samples from our center. In vitro and in vivo experiments revealed that blocking CASR with lentivirus could suppress tumor growth and invasion, and EMT progress in KIRC cells. In summary, our study provides a comprehensive bioinformatic analysis of CASR in pan-cancer, offering deeper insights into its function and the EMT mechanism in KIRC, warranting further investigation.

Assessment of NLRP3 Gene Polymorphisms with Periodontitis as Compared with Healthy Periodontium in Iraqi Arabs Patients

OBJECTIVES

 The nod-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasome regulates the maturation and release of the cytokines as well as the activation of caspase in response to danger signals derived from pathogenic infection, tissue damage, andmetabolic changes that have a role in the pathogenesis of different diseases as periodontitis. Yet, the susceptibility to this illness could be determined by population-based genetic differences. The aim of this study was to determine whether periodontitis in Arab populations from Iraq is correlated with NLRP3 gene polymorphisms and measure clinical periodontal parameters and investigate their association with genetic polymorphisms of the NLRP3.

MATERIALS AND METHODS

 The study sample consisted of 94 participants ranging from 30 to 55 years old, both males and females who fulfilled the study's criteria. The selected participants were divided into two groups: the periodontitis group (62 subjects) and the healthy control group (32 subjects). The examination of clinical periodontal parameters of all participants was carried out, followed by a collection of venous blood for NLRP3 genetic analysis using the polymerase chain reaction-sequencing technique.

RESULTS

 The genetic analysis of NLRP3 genotypes at four single nucleotide polymorphisms (SNPs) (rs10925024, rs4612666, rs34777555, and rs10754557), by Hardy-Weinberg equilibrium, identified nonsignificant differences in studied groups. The C-T genotype among periodontitis was significantly different from controls, while the C-C genotype among control was significantly different from periodontitis at NLRP3 rs10925024. Overall, there were 35 SNPs in the periodontitis group and 10 SNPs in the control group for rs10925024 with significant differences versus nonsignificant differences of the other SNPs between the studied groups. Clinical attachment loss and NLRP3 rs10925024 additionally demonstrated a significant positive correlation in the periodontitis subjects.

CONCLUSION

 The findings suggested that polymorphisms of the NLRP3 gene may have a role and increasing the genetic susceptibility to periodontal disease in Arabs Iraqi patients.

New insight in urological cancer therapy: From epithelial-mesenchymal transition (EMT) to application of nano-biomaterials

A high number of cancer-related deaths (up to 90) are due to metastasis and simple definition of metastasis is new colony formation of tumor cells in a secondary site. In tumor cells, epithelial-mesenchymal transition (EMT) stimulates metastasis and invasion, and it is a common characteristic of malignant tumors. Prostate cancer, bladder cancer and renal cancer are three main types of urological tumors that their malignant and aggressive behaviors are due to abnormal proliferation and metastasis. EMT has been well-documented as a mechanism for promoting invasion of tumor cells and in the current review, a special attention is directed towards understanding role of EMT in malignancy, metastasis and therapy response of urological cancers. The invasion and metastatic characteristics of urological tumors enhance due to EMT induction and this is essential for ensuring survival and ability in developing new colonies in neighboring and distant tissues and organs. When EMT induction occurs, malignant behavior of tumor cells enhances and their tend in developing therapy resistance especially chemoresistance promotes that is one of the underlying reasons for therapy failure and patient death. The lncRNAs, microRNAs, eIF5A2, Notch-4 and hypoxia are among common modulators of EMT mechanism in urological tumors. Moreover, anti-tumor compounds such as metformin can be utilized in suppressing malignancy of urological tumors. Besides, genes and epigenetic factors modulating EMT mechanism can be therapeutically targeted for interfering malignancy of urological tumors. Nanomaterials are new emerging agents in urological cancer therapy that they can improve potential of current therapeutics by their targeted delivery to tumor site. The important hallmarks of urological cancers including growth, invasion and angiogenesis can be suppressed by cargo-loaded nanomaterials. Moreover, nanomaterials can improve chemotherapy potential in urological cancer elimination and by providing phototherapy, they mediate synergistic tumor suppression. The clinical application depends on development of biocompatible nanomaterials.

Salivary E-cadherin as a biomarker for diagnosis and predicting grade of periodontitis

OBJECTIVES

To determine the abilities of salivary E-cadherin to differentiate between periodontal health and periodontitis and to discriminate grades of periodontitis.

BACKGROUND

E-cadherin is the main protein responsible for maintaining the integrity of epithelial-barrier function. Disintegration of this protein is one of the events associated with the destructive forms of periodontal disease leading to increase concentration of E-cadherin in the oral biofluids.

MATERIALS AND METHODS

A total of 63 patients with periodontitis (case) and 35 periodontally healthy subjects (control) were included. For each patient, periodontal parameters including bleeding on probing (BOP), probing pocket depth (PPD), and clinical attachment level (CAL) were recorded. Concentration of salivary E-cadherin was determined by ELISA. Receiver operating characteristic (ROC) curve and area under the curve (AUC) were used to determine the diagnostic potentials of E-cadherin.

RESULTS

Level of salivary E-cadherin was significantly higher in periodontitis cases than controls. The ROC analysis showed that salivary E-cadherin exhibits excellent sensitivity and specificity (AUC 1.000) to differentiate periodontal health from periodontitis with a cutoff concentration equal to 1.325 ng/mL. The AUCs of E-cadherin to differentiate grade A from grade B and C periodontitis were 0.731 (cutoff point = 1.754 ng/mL) and 0.746 (cutoff point = 1.722 ng/mL), respectively. However, the AUC of salivary E-cadherin to differentiate grade B from grade C periodontitis was lower (0.541). Additionally, BOP and PPD were significantly and positively correlated with the concentration of salivary E-cadherin.

CONCLUSION

Salivary E-cadherin exhibited excellent sensitivity and specificity to differentiate periodontitis from a healthy periodontium. The level of accuracy of E-cadherin was also sufficient to recognize grade A periodontitis from grade B and C periodontitis.

Gingival tissue samples from periodontitis patients demonstrate epithelial-mesenchymal transition phenotype

OBJECTIVE

To determine the expression of key epithelial-mesenchymal transition (EMT) markers in gingival tissue samples collected from patients with periodontitis.

BACKGROUND

Epithelial-mesenchymal transition is a process responsible for shifting epithelial-phenotype to mesenchymal-phenotype leading to loss of epithelial-barrier function. Thus, EMT could be involved as a pathogenic mechanism in periodontitis as both conditions share common promoters and signalling pathways.

MATERIALS AND METHODS

Gingival tissue samples were collected from patients with periodontitis (case) and healthy periodontium (control). Periodontal parameters including bleeding on probing, probing pocket depth (PPD), and clinical attachment loss were recorded. Paraffinized tissue samples were processed and immunohistochemically stained to determine the expression of key EMT markers which included E-cadherin, β-catenin, Snail1 and vimentin.

RESULTS

The majority of cases (n = 65, 72.2%) were diagnosed with periodontitis stage 3 or 4, grade b or c vs 25 (27.8%) subjects with intact healthy periodontium. Discontinuity of epithelium was detected in up to 80.9% of periodontitis cases associated with reduced number of epithelial layers as compared to controls. Immunohistochemical expression of epithelial markers (E-cadherin and β-catenin) was significantly downregulated in periodontitis patients as compared with controls. Periodontitis cases exhibited significant upregulation of Snail1 expression. Furthermore, cytoplasmic vimentin (66.2%) and nuclear β-catenin (27.7%) were solely expressed in periodontally diseased tissues compared with control. Epithelial markers, E-cadherin and β-catenin, were significantly negatively correlated with increasing PPD, while vimentin showed positive correlation with this parameter.

CONCLUSION

There were marked downregulation of epithelial molecules and upregulation of mesenchymal markers in gingival tissues derived from periodontitis patients, suggesting expression of the EMT phenotype in the pathological epithelial lining of periodontal pockets.

Cytokines secreted by inflamed oral mucosa: implications for oral cancer progression

The oral mucosa has an essential role in protecting against physical, microbial, and chemical harm. Compromise of this barrier triggers a wound healing response. Key events in this response such as immune infiltration, re-epithelialization, and stroma remodeling are coordinated by cytokines that promote cellular migration, invasion, and proliferation. Cytokine-mediated cellular invasion and migration are also essential features in cancer dissemination. Therefore, exploration of cytokines that regulate each stage of oral wound healing will provide insights about cytokines that are exploited by oral squamous cell carcinoma (SCC) to promote tumor development and progression. This will aid in identifying potential therapeutic targets to constrain SCC recurrence and increase patient survival. In this review, we discuss cytokines that overlap in oral wounds and SCC, emphasizing how these cytokines promote cancer progression.

Nano-Based Drug Delivery Systems for Periodontal Tissue Regeneration

Periodontitis is a dysbiotic biofilm-induced and host-mediated inflammatory disease of tooth supporting tissues that leads to progressive destruction of periodontal ligament and alveolar bone, thereby resulting in gingival recession, deep periodontal pockets, tooth mobility and exfoliation, and aesthetically and functionally compromised dentition. Due to the improved biopharmaceutical and pharmacokinetic properties and targeted and controlled drug release, nano-based drug delivery systems have emerged as a promising strategy for the treatment of periodontal defects, allowing for increased efficacy and safety in controlling local inflammation, establishing a regenerative microenvironment, and regaining bone and attachments. This review provides an overview of nano-based drug delivery systems and illustrates their practical applications, future prospects, and limitations in the field of periodontal tissue regeneration.