Nuclear morphological changes in gingival epithelial cells of patients with periodontitis

Is micronucleus assay a useful marker in gingiva, tongue, and palate for evaluating cytogenetic damage induced by chemical, physical, and biological agents in vivo? A systematic review with meta-analysis

The present systematic review (SR) aims to evaluate manuscripts in order to help further elucidate the following question: is the micronucleus assay (MA) also a useful marker in gingiva, tongue, and palate for evaluating cytogenetic damage in vivo? A search was performed through the electronic databases PubMed/Medline, Scopus, and Web of Science, all studies published up to December 2023. The comparisons were defined as standardized mean difference (SMD), and 95% confidence intervals (CIs) were established. Full manuscripts from 34 studies were carefully selected and reviewed in this setting. Our results demonstrate that the MA may be a useful biomarker of gingival tissue damage in vivo, and this tissue could be a useful alternative to the buccal mucosa. The meta-analysis analyzing the different sites regardless of the deleterious factor studied, the buccal mucosa (SMD = 0.69, 95% CI, - 0.49 to 1.88, p = 0.25) and gingiva (SMD = 0.31, 95% CI, - 0.11 to 0.72, p = 0.15), showed similar results and different outcome for the tongue (SMD = 1.19, 95% CI, 0.47 to 1.91, p = 0.001). In summary, our conclusion suggests that the MA can be a useful marker for detecting DNA damage in gingiva in vivo and that this tissue could be effective site for smearing.

NLRP3 Inflammasome in Autoinflammatory Diseases and Periodontitis Advance in the Management

Inflammatory chemicals are released by the immune system in response to any perceived danger, including irritants and pathogenic organisms. The caspase activation and the response of inflammation are governed by inflammasomes, which are sensors and transmitters of the innate immune system. They have always been linked to swelling and pain. Research has mainly concentrated on the NOD-like protein transmitter 3 (NLRP3) inflammasome. Interleukin (IL)-1 and IL-18 are pro-inflammatory cytokines that are activated by the NOD-like antibody protein receptor 3 (NLRP3), which controls innate immune responses. The NLRP3 inflammasome has been associated with gum disease and other autoimmune inflammatory diseases in several studies. Scientists' discovery of IL-1's central role in the pathophysiology of numerous autoimmune disorders has increased public awareness of these conditions. The first disease to be connected with aberrant inflammasome activation was the autoinflammatory cryopyrin-associated periodic syndrome (CAPS). Targeted therapeutics against IL-1 have been delayed in development because their underlying reasons are poorly understood. The NLRP3 inflammasome has recently been related to higher production and activation in periodontitis. Multiple periodontal cell types are controlled by the NLRP3 inflammasome. To promote osteoclast genesis, the NLRP3 inflammasome either increases receptor-activator of nuclear factor kappa beta ligand (RANKL) synthesis or decreases osteoclast-promoting gene (OPG) levels. By boosting cytokines that promote inflammation in the periodontal ligament fibroblasts and triggering apoptosis in osteoblasts, the NLRP3 inflammasome regulates immune cell activity. These findings support further investigation into the NLRP3 inflammasome as a therapeutic target for the medical treatment of periodontitis. This article provides a short overview of the NLRP3 inflammatory proteins and discusses their role in the onset of autoinflammatory disorders (AIDs) and periodontitis.

Nuclear aberrations in the gingival epithelium of patients with chronic periodontitis

Context

Periodontitis characterized by mild symptoms in the early stages, which makes diagnostics problematic. The gingival epithelium can be used for micronucleus assay since gums are the area affected by the disease.

Aims

The aim of the study was to study the frequency of occurrence and the range of nuclear anomalies in gingival epithelium of healthy people and people with periodontitis.

Settings and Design

Scrapings of the gingival epithelium were made next to the central incisors (1.1) and molar teeth (1.7) in control and experimental groups (ten healthy males 35-50 years old and 10 males with periodontitis).

Materials and Methods

The preparations were stained by Romanowsky-Giemsa. The frequency of nuclear aberrations (‰), the accumulation index, and the repair index were determined.

Statistical Analysis Used

The differences in the medians of nuclear aberrations were determined using Wilcoxon and the Van-der-Waerden tests. The pathology proportions were compared using the Z-test. To determine the predictors of periodontitis, receiver operator characteristic analysis was used. For multiple comparisons, the Bonferroni correction was used.

Results

In the experimental group, the range of nuclear aberrations was wider, the ratio of karyolysis in the unaffected area was higher, than that in control; perinuclear vacuoles were fewer and macronuclei were more in the affected area. The frequency of cells with micronuclei over 1.33‰ in the affected area is the periodontitis marker.

Conclusions

Gingival epithelium can be used in micronucleus assay. Micronucleus test revealed a wider range of nuclear aberrations in the cells of the gingival epithelium and a higher frequency of occurrence of micronuclei in patients with periodontal disease compared to healthy subjects. Therefore, cytological signs of the inflammation appear earlier than the clinical ones and are verified more clearly. The markers of apoptosis and destruction of nuclei, and low repair index indicate normal elimination of damaged cells. An increased accumulation index in people with periodontitis may indicate the risk of malignant tumors.

The effects of smoking on genotoxic and histopathologic damage in exfoliated oral epithelial cells and the periodontium: A cross-sectional study

Smoking negatively affects the prognosis of periodontal disease by impairing tissue healing. While micronucleus is the most popular parameter for demonstrating DNA damage, inflammatory cell and vascular densities are the most evaluated parameters for determining histopathologic changes in the periodontium. This study aimed to study the effects of periodontitis and cigarette smoking on genotoxic changes in exfoliated oral epithelial cells and histopathologic changes in periodontal tissue. A cross-sectional study was conducted between November 2018 and July 2019 at a dental university hospital in Turkey, and registered as NCT05484765. Eighty systemically healthy subjects were divided into four groups according to periodontal status and smoking habits: 20 smokers with generalized periodontitis (SGP), 20 nonsmokers with generalized periodontitis (NGP), 20 smokers with healthy periodontium (SHP), and 20 nonsmokers with healthy periodontium (NHP). For each study participant, full-mouth clinical periodontal parameters (CPPs) were measured, smear samples were taken from buccal and gingival mucosa, and periodontal tissue was biopsied from the maxillary molars. Cytogenetic and histopathologic assays (primary and secondary outcomes) were conducted using Feulgen reaction and hematoxylin-eosin staining, respectively. The mean CPPs of healthy periodontium groups were lower than generalized periodontitis groups. No significant differences were found between other groups regarding CPPs. Buccal micronuclei counts in groups decreased with the highest to lowest counts occurring in the order SGP > SHP > NGP > NHP. Gingival micronuclei counts in groups decreased from SGP > SHP > NGP = NHP. The most intense inflammatory cell and vascular densities occurred in SGP and NGP groups, respectively; and the mildest values were in healthy periodontium groups. Histopathological damage score decreased significantly by group in order SGP > NGP > SHP > NHP. The synergy arising from the combination of smoking and periodontitis exposures exacerbates genotoxic and histopathologic damage in oral cells and the periodontium.

Genomic instability in people living with HIV

The increased life expectancy of people living with HIV (PLWH) receiving antiretroviral treatment (ART) has transformed HIV infection into a chronic disease. However, patients may be at risk of accelerated aging and the accumulation of cellular damage, which may trigger the development of cancer. We evaluated genomic instability in HIV-positive individuals with different viral loads receiving antiretroviral treatment (ART) and in HIV ART-naïve individuals. We included 67 participants divided into four groups: group 1 (n = 24) HIV patients receiving reverse-transcriptase inhibitors (tenofovir/ emtricitabine/ efavirenz and abacavir/ lamivudine/ efavirenz), group 2 (n = 22) HIV patients receiving protease inhibitors combined with other antiretroviral drugs (tenofovir/ emtricitabine with ritonavir/ atazanavir or lopinavir/ ritonavir, and darunavir/ ritonavir/ raltegravir), group 3 (n = 13) HIV ART-naïve patients, and group 4 (n = 8) healthy individuals (controls). Nuclear abnormalities in buccal mucosal samples (micronuclei, binucleated cells, nuclear buds, karyorrhexis, karyolysis, and pyknosis) were quantified. Simultaneously, blood samples were taken to quantify CD4+, CD8+, and HIV viral load. There was a significant age difference between HIV ART-naïve patients and receiving ART groups. Infection time was longer in HIV patients with ART than in ART-naïve patients. There were no differences in sex, smoking, alcohol consumption, or number of micronucleated cells between the study groups. We found higher frequencies of binucleated cells and nuclear buds in HIV patients, HIV ART-naïve, and HIV ART patients compared to the control group. We found a positive correlation between nuclear buds and CD4/CD8 ratio in the HIV ART-naïve group. In conclusion, PLWH showed increased genomic instability. The CD4/CD8 ratio affects the numbers of nuclear buds and binucleated cells. These findings are pertinent to mechanisms of damage and possible strategies to mitigate carcinogenesis in PLWH.

Cellular and Biochemical Changes in Different Categories of Periodontitis: A Patient-based Study

Objectives:

The aim of this study was to study the effects of periodontitis, diabetes mellitus (DM), and tobacco smoking and chewing habits (TBSCH) on the oxidative stress biomarker levels, namely malondialdehyde (MDA), and the mucosal genotoxic nuclear damage in the marginal gingival cells of subjects. Furthermore, the correlation of the biomarkers, MDA, and nuclear changes in the form of micronucleation (Mn) and binucleation (Bn) was investigated.

Materials and Methods:

Forty study participants were divided into five subject categories, which were established based on the presence of periodontitis, DM, and TBSCH. Whole saliva and marginal gingival smears collected from subjects were used to determine MDA levels and nuclear changes, respectively. A full-mouth assessment of periodontal pocket depth, clinical attachment loss, and bleeding on probing was performed for each subject to determine periodontal status.

Results:

MDA and Mn levels between control group and subjects with only periodontitis (MDA: P < 0.9990; Mn: P < 0.8200) showed no significant difference, whereas levels among subjects with DM, TBSCH, and periodontitis, and all other categories were statistically significant (MDA: P < 0.001). DM and/or TBSCH superimposed on periodontitis cause an exponential increase in biomarker levels. Furthermore, MDA and Mn showed poor correlation (r = 0.162; P = 0.318). Periodontitis alone did not significantly increase oxidative stress levels compared to healthy controls, whereas DM and TBSCH resulted in augmented oxidative stress levels, implying that increased stress produced by DM and TBSCH aggravates or exaggerates periodontal inflammation.

Conclusion:

Poor correlation between MDA and Mn indicated that the mechanisms involved in their production are independent of each other.

DNA Laddering to Evaluate Cytogenetic Damage in Patients with Periodontitis

Background:

Inflammatory conditions show cytogenetic damage in peripheral blood leukocytes and this can be assessed using various tests. Cytogenetic damage as observed in the peripheral blood cells, is a marker of periodontal disease. DNA laddering is a sensitive assay which evaluates the cytogenetic damage. DNA laddering is a feature that can be observed when DNA fragments, resulting from apoptotic DNA fragmentation, are visualised after separation by gel electrophoresis which results in a characteristic “ladder” pattern.

Aim:

The aim of the present study is to investigate the cytogenetic damage in different forms of periodontitis in comparison with healthy controls.

Materials and Methods:

In this cross-sectional study, 15 systemically healthy subjects with moderate to severe chronic periodontitis (CGP), 15 systemically healthy subjects with generalised aggressive periodontitis(GAP) and 15 systemically healthy control subjects were recruited. Blood samples of the patients were drawn and evaluated for the cytogenetic damage by DNA laddering.

Results:

Apoptotic DNA fragmentation was observed as a “ladder” pattern at 180-200 BP intervals in both CGP and GAP groups indicating the DNA damage, in contrast with the healthy group where the ladder pattern was not observed suggesting of the healthy DNA.

Conclusion:

The results indicated that there are cytogenetic damages in both the chronic and aggressive periodontitis groups incontrast to the healthy controls.