Pregnancy-induced gingivitis and OMICS in dentistry: in silico modeling and in vivo prospective validation of estradiol-modulated inflammatory biomarkers

The effect of sex steroid hormones on the ecology of in vitro oral biofilms

Sex steroid hormones (SSH) such as oestrogen, progesterone and testosterone are cholesterol derived molecules that regulate various physiological processes. They are present in both blood and saliva, where they come in contact with oral tissues and oral microorganisms. Several studies have confirmed the effect of these hormones on different periodontal-disease-associated bacteria, using single-species models. Bacteria can metabolize SSH, use them as alternative for vitamin K and also use them to induce the expression of virulence factors. However, it is still unclear what the effects of SSH are on the oral microbiome. In this study, we investigated the effects of four SSH on commensal in vitro oral biofilms. Saliva-derived oral biofilms were grown in Mc Bain medium without serum or menadione using the Amsterdam Active-Attachment model. After initial attachment in absence of SSH, the biofilms were grown in medium containing either oestradiol, oestriol, progesterone or testosterone at a 100-fold physiological concentration. Menadione or ethanol were included as positive control and negative control, respectively. After 12 days with daily medium refreshments, biofilm formation, biofilm red fluorescence and microbial composition were determined. The supernatants were tested for proteolytic activity using the Fluorescence Resonance Energy Transfer Analysis (FRET). No significant differences were found in biofilm formation, red fluorescence or microbial composition in any of the tested groups. Samples grown in presence of progesterone and oestradiol showed proteolytic activity comparable to biofilms supplemented with menadione. In contrast, testosterone and oestriol showed a decreased proteolytic activity compared to biofilms grown in presence of menadione. None of the tested SSH had large effects on the ecology of in vitro oral biofilms, therefore a direct translation of our results into in vivo effects is not possible. Future experiments should include other host factors such as oral tissues, immune cells and combinations of SSH as present in saliva, in order to have a more accurate picture of the phenomena taking place in both males and females.

Detection and quantification of TIMP1 and miR-141 through RT-LAMP and TT-LAMP in serum samples during estrous cycle in buffalo

Estrus identification is a common problem in the reproductive management of farm animals. Hence, several studies have been conducted to explore biomarkers for estrus detection. One of our previous studies identified the abundance of RNA biomarkers such as TIMP1 and miR-141 in buffalo saliva during the estrus stage. However, the level of these RNA biomarkers in buffalo serum during estrous cycle is undetected. Therefore, the present study was designed to quantify TIMP1 and miR-141 in serum during buffalo estrous cycle. Blood samples were collected in different stages of estrous cycle from four healthy cyclic buffaloes. The quantification of TIMP1 and miR-141 was performed with direct serum using RT-LAMP and TT-LAMP technologies, respectively. The LAMP amplification was confirmed by agarose gel electrophoresis and the color change was quantified in comparison to a non-template control using ImageJ software. A decreased abundance of TIMP1 at the diestrus stage and a decreasing trend of miR-141 from proestrus to diestrus stages were observed, which was further reinforced by simulated random populations generated with R programming. Specifically, TIMP1 was found significantly (P < 0.0001) abundant at estrus and metestrus stages as compared to the diestrus stage, whereas miR-141 was significantly (P < 0.001) higher during the proestrus stage as compared to the other stages of estrous cycle. The ROC curve analysis showed miR-141 to be a better biomarker than TIMP1 as it distinguished the proestrus stage from diestrus with a sensitivity and specificity of 83 % and 98 %. This study also marked the first use of TT-LAMP technology for rapid miRNA detection in livestock.

Inflammatory Response in Oral Biofilm during Pregnancy: A Systematic Review

Understanding the inflammatory response in oral biofilm during pregnancy and its association with oral and maternal health is essential for identifying biomarker patterns that may serve as markers of pregnancy-related complications. We aimed to conduct a systematic review of the available literature to assess: (1) inflammatory responses in oral biofilm during pregnancy, (2) the association between inflammatory responses in oral biofilm during pregnancy and maternal, oral or systemic conditions, (3) changes in the response of inflammatory biomarkers found in the oral biofilm during different pregnancy stages, and (4) the value of other risk factors such as nutrition and lifestyle. PubMed, Web of Science and Cochrane Library were systematically searched from inception until April 2022. From 5441 records, 39 studies were included for qualitative assessment. The oral biofilm in pregnant women was associated with increased inflammatory biomarkers when compared to non-pregnant women. Levels of inflammatory biomarkers in the oral biofilm were found to be highest in pregnant women with systemic conditions. Increased inflammatory biomarkers in the oral biofilm were also associated with worse oral health outcomes. Given the importance of nutrition and lifestyle for pregnancy and oral health outcomes and the fact that these factors were largely excluded in the included studies, future research should consider a holistic view of the mother during pregnancy to capture physiological, hormonal, immunologic, and metabolic changes in the context of inflammatory responses.

Influence of Gestational Hormones on the Bacteria-Induced Cytokine Response in Periodontitis

Periodontitis is an inflammatory disease that affects the supporting structures of teeth. The presence of a bacterial biofilm initiates a destructive inflammatory process orchestrated by various inflammatory mediators, most notably proinflammatory cytokines, which are upregulated in the gingival crevicular fluid, leading to the formation of periodontal pockets. This represents a well-characterized microbial change during the transition from periodontal health to periodontitis; interestingly, the gestational condition increases the risk and severity of periodontal disease. Although the influence of periodontitis on pregnancy has been extensively reviewed, the relationship between pregnancy and the development/evolution of periodontitis has been little studied compared to the effect of periodontitis on adverse pregnancy outcomes. This review is aimed at summarizing the findings on the pregnancy-proinflammatory cytokine relationship and discussing its possible involvement in the development of periodontitis. We address (1) an overview of periodontal disease, (2) the immune response and possible involvement of proinflammatory cytokines in the development of periodontitis, (3) how bone tissue remodelling takes place with an emphasis on the involvement of the inflammatory response and metalloproteinases during periodontitis, and (4) the influence of hormonal profile during pregnancy on the development of periodontitis. Finally, we believe this review may be helpful for designing immunotherapies based on the stage of pregnancy to control the severity and pathology of periodontal disease.

Periodontal Conditions and Pathogens Associated with Pre-Eclampsia: A Scoping Review

BACKGROUND

Pre-eclampsia, the second most frequent direct source of maternal mortality, is a multisystem gestational disorder characterized by proteinuria and maternal hypertension after the 20th gestational week. Although the causes of pre-eclampsia are still discussed, research has suggested that the placenta has a central place in the pathogenesis of this disease. Moreover, current surveys indicated that periodontal disorders observed during the pregnancy and more particularly, periodontal pathogens could be link to the risk of pre-eclampsia.

OBJECTIVES

This article aims to review recent studies focusing on periodontal conditions and pathogens associated with pre-eclampsia.

METHODS

The process followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews guidelines.

RESULTS

Metabolic conditions, immunological changes, fluctuating progesterone and estrogen levels of the pregnant woman induce a dysbiosis of the oral microbiota and contribute to increase inflammation of periodontal tissues. Periodontal pathogens could diffuse through the bloodstream inducing a placenta inflammatory response as well as inflammatory molecules produced in response to periodontopathogens could migrate through the bloodstream leading to a placenta inflammatory response. Also, periodontopathogens can colonize the vaginal microbiota through the gastrointestinal tract or during oro-genital contacts.

CONCLUSION

A cumulative bi-directional relationship between periodontal conditions, pathogens and the pre-eclampsia exists.

Regulation of matrix metalloproteinases-8, -9 and endogenous tissue inhibitor-1 in oral biofluids during pregnancy and postpartum

OBJECTIVE

During pregnancy, mothers undergoe considerable physiological changes affecting the whole body including periodontal tissues. Susceptibility to gingival inflammation during pregnancy could be mediated by modulation of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs). Therefore, the aim of this study was to investigate salivary and gingival crevicular fluid (GCF) levels of MMPs and TIMPs during the second and third trimester of pregnancy and postpartum.

DESIGN

Saliva and GCF samples were collected from 96 pregnant women (PW) before and after giving birth. The sixty matched non-pregnant women (N-PW) were recruited as a control group and full-mouth periodontal examination was performed. The levels of MMP-8, MMP-9 and TIMP-1 were determined by immunofluorometric and enzyme-linked immunosorbent assays.

RESULTS

The PW group exhibited significantly higher levels of MMP-8 and MMP-9 in their saliva than the N-PW group while corresponding salivary TIMP-1 levels were significantly lower in NPW compared to the postpartum stage. This resulted in significantly higher MMP-8/TIMP-1 and MMP-9/TIMP-1ratio in the saliva from PW before and after birth than in that from N-PW. MMP-8, MMP-9 and TIMP-1 levels were higher in GCF from PW and postpartum than in that from N-PW.

CONCLUSIONS

MMP-8 and MMP-9 levels in saliva and GCF reflect inflammatory burden during pregnancy. They could be used for monitoring the inflammatory state of gingival tissues during pregnancy.

Correlation of periodontal and microbiological evaluations, with serum levels of estradiol and progesterone, during different trimesters of gestation

Our purpouse was to identify quantitatively and qualitatively the subgingival flora in different gestational trimesters, compared to non-pregnant women; evaluating the correlations between epidemiological characteristics, clinical diagnosis, microbiological findings and levels of estradiol and progesterone. 52 pregnant women divided into 3 groups, according to the gestational trimester and 15 non-pregnant patients, without hormonal contraceptives, were evaluated. Plaque index (PI), gingival index (GI), probing depth (PD) and clinical attachment level (CAL) were evaluated. Subgingival biofilm samples were processed by the qPCR technique and the serum levels of estradiol and progesterone quantified by chemiluminescence. Clinical diagnosis during gestation was correlated with the total bacterial count. A higher prevalence of Tannerella forsythia (Tf) was identified in first trimester of pregnancy and this periodontopathogen was correlated with the diagnosis of gingivitis among pregnant women. Porphyromonas gingivalis (Pg) showed a positive correlation with progesterone levels in the first trimester. High prevalence of periodontopathogens was noticed in this population. Clinical diagnosis in gestation was positively correlated with the total amount of bacteria, without influence of the hormonal levels or the epidemiological factors evaluated. The presence of Tf favored occurrence of gingivitis during pregnancy and the progesterone levels in the first trimester enhanced the growth of Pg.

Comparative Analysis of Gene Expression Patterns for Oral Epithelium-Related Functions with Aging

Epithelial cells and functions of the epithelium are critical to the health of the oral cavity. We used a nonhuman primate model to profile the transcriptome of gingival tissues in health across the lifespan and hypothesized that in older animals, epithelial-related transcriptome patterns would reflect epithelial cells that are aggressively responsive to the surrounding environment and less able to modulate and resolve the noxious challenge from the bacteria. Rhesus monkeys (n = 34) with a healthy periodontium were distributed into four groups: ≤3 years (young), 3-7 years (adolescent), 12-16 years (adult), and 18-23 years (aged), and a buccal gingival sample from the premolar/molar region of each animal was obtained. RNA was subjected to a microarray analysis (GeneChip^® Rhesus Macaque Genome Array, Affymetrix), and 336 genes examined that are linked to epithelium and epithelial cell functions categorized into 9 broad functional groups: extracellular matrix and cell structure; extracellular matrix remodeling enzymes; cell adhesion molecules, cytoskeleton regulation; inflammatory response; growth factors; kinases/cell signaling; cell surface receptors; junction associated molecules; autophagy/apoptosis; antimicrobial peptides; and transcription factors. Total of 255 genes displayed a normalized signal >100, and differences across the age groups were observed primarily in extracellular matrix and cell structure, cell adhesion molecules, and cell surface receptor gene categories with elevations in the aged tissues. Keratins 2, 5, 6B, 13, 16, 17 were all significantly increased in healthy-aged tissues versus adults, and keratins 1 and 2 were significantly decreased in young animals. Approximately 15 integrins are highly expressed in the gingival tissues across the age groups with only ITGA8, ITGAM (CD11b), and ITGB2 significantly increased in the aged tissues. Little impact of aging on desmosomal/hemidesmosomal genes was noted. These results suggest that healthy gingival aging has a relatively limited impact on the broader functions of the epithelium and epithelial cells, with some effects on genes for extracellular matrix and cell adhesion molecules (e.g., integrins). Thus, while there is a substantial impact of aging on immune system targets even in healthy gingiva, it appears that the epithelial barrier remains reasonably molecularly intact in this model system.

Blood metal levels and third trimester maternal plasma matrix metalloproteinases (MMPs)

While it is known that in utero exposure to environmental toxicants, namely heavy metals, can adversely affect the neonate, there remains a significant paucity of information on maternal biological changes specific to metal exposures during pregnancy. This study aims at identifying associations between maternal metal exposures and matrix metalloproteinases (MMPs) that are known to be engaged in pregnancy process. Third trimester maternal plasma (n = 1533) from a pregnancy cohort (Maternal-Infant Research on Environmental Chemicals Study, MIREC) were analyzed for MMP-1,-2,-7,-9 and -10 by affinity-based multiplex protein array analyses. Maternal metal concentrations (mercury, cadmium, lead, arsenic and manganese) in 1st and 3rd trimesters exhibited strong correlations (p < 0.05). Multivariate regression models were used to estimate odds ratio (OR) for the association between metal concentrations in quartiles and high (90%) and low (10%) maternal MMP levels. Significant (p < 0.05) metal exposure-related effects were observed with the different MMP isoform responses. MMP profiles were specific to the trimester at which the maternal blood metals were analyzed. Our findings suggest that the profiles of these MMP isoforms vary with the type of metal exposure, blood metal concentrations and the trimester at which metal levels were determined. These new findings on maternal metal-MMP relationships can guide future explorations on toxicity mechanisms relevant to metal exposure-mediated adverse birth outcomes.

Salivary antimicrobial defensins in pregnancy

AIM

Susceptibility to and severity of gingival inflammation are enhanced during pregnancy; however, regulation of oral innate immune response, including antimicrobial peptides, during pregnancy is still unknown. We analysed salivary levels of human beta-defensin (hBD)-1, -2, -3, and human neutrophil peptide (HNP)-1 in pregnant women, and related those to their periodontal status.

MATERIAL AND METHODS

In this cohort study, 30 generally healthy, non-smoking Caucasian women without periodontitis were followed at three time points during pregnancy and twice post-partum. The non-pregnant group consisted of 24 women, who were examined three times at the following months. At each visit, periodontal status was recorded and stimulated saliva samples were collected. Salivary estradiol, progesterone, and defensin concentrations were measured by ELISA assays.

RESULTS

After adjusting for visible plaque and gingival bleeding, reduced salivary concentrations of hBD-1, hBD-2, and HNP-1 were found especially during the third trimester, whereas hBD-3 concentrations did not change during pregnancy and post-partum visits. Weak associations were observed between salivary defensin and hormone concentrations and clinical parameters.

CONCLUSION

There seems to be an independent regulation cascade for each antimicrobial defensin in the oral cavity during pregnancy, despite of the similarities between these antimicrobial peptides.

A Systems Biology Approach to Reveal Putative Host-Derived Biomarkers of Periodontitis by Network Topology Characterization of MMP-REDOX/NO and Apoptosis Integrated Pathways

Periodontitis, a formidable global health burden, is a common chronic disease that destroys tooth-supporting tissues. Biomarkers of the early phase of this progressive disease are of utmost importance for global health. In this context, saliva represents a non-invasive biosample. By using systems biology tools, we aimed to (1) identify an integrated interactome between matrix metalloproteinase (MMP)-REDOX/nitric oxide (NO) and apoptosis upstream pathways of periodontal inflammation, and (2) characterize the attendant topological network properties to uncover putative biomarkers to be tested in saliva from patients with periodontitis. Hence, we first generated a protein-protein network model of interactions ("BIOMARK" interactome) by using the STRING 10 database, a search tool for the retrieval of interacting genes/proteins, with "Experiments" and "Databases" as input options and a confidence score of 0.400. Second, we determined the centrality values (closeness, stress, degree or connectivity, and betweenness) for the "BIOMARK" members by using the Cytoscape software. We found Ubiquitin C (UBC), Jun proto-oncogene (JUN), and matrix metalloproteinase-14 (MMP14) as the most central hub- and non-hub-bottlenecks among the 211 genes/proteins of the whole interactome. We conclude that UBC, JUN, and MMP14 are likely an optimal candidate group of host-derived biomarkers, in combination with oral pathogenic bacteria-derived proteins, for detecting periodontitis at its early phase by using salivary samples from patients. These findings therefore have broader relevance for systems medicine in global health as well.

[Lipids peroxidation system in oral fluid of pregnant women with inflammatory periodontal disease at different gestation stages]

Oxidative stress was assessed in 30 pregnant women with inflammatory periodontal disease and 20 healthy non-pregnant women. An increase of lipids peroxidation intensity and decrease of antioxidative enzymes was revealed. These changes progressed during the course of gestation reaching its peak in the III trimester and were associated with the clinical signs of periodontal disease.

Materiomics for Oral Disease Diagnostics and Personal Health Monitoring: Designer Biomaterials for the Next Generation Biomarkers

We live in exciting times for a new generation of biomarkers being enabled by advances in the design and use of biomaterials for medical and clinical applications, from nano- to macro-materials, and protein to tissue. Key challenges arise, however, due to both scientific complexity and compatibility of the interface of biology and engineered materials. The linking of mechanisms across scales by using a materials science approach to provide structure-process-property relations characterizes the emerging field of 'materiomics,' which offers enormous promise to provide the hitherto missing tools for biomaterial development for clinical diagnostics and the next generation biomarker applications towards personal health monitoring. Put in other words, the emerging field of materiomics represents an essentially systematic approach to the investigation of biological material systems, integrating natural functions and processes with traditional materials science perspectives. Here we outline how materiomics provides a game-changing technology platform for disruptive innovation in biomaterial science to enable the design of tailored and functional biomaterials--particularly, the design and screening of DNA aptamers for targeting biomarkers related to oral diseases and oral health monitoring. Rigorous and complementary computational modeling and experimental techniques will provide an efficient means to develop new clinical technologies in silico, greatly accelerating the translation of materiomics-driven oral health diagnostics from concept to practice in the clinic.

Salivary markers of oxidative stress in oral diseases

Saliva is an interesting alternative diagnostic body fluid with several specific advantages over blood. These include non-invasive and easy collection and related possibility to do repeated sampling. One of the obstacles that hinders the wider use of saliva for diagnosis and monitoring of systemic diseases is its composition, which is affected by local oral status. However, this issue makes saliva very interesting for clinical biochemistry of oral diseases. Periodontitis, caries, oral precancerosis, and other local oral pathologies are associated with oxidative stress. Several markers of lipid peroxidation, protein oxidation and DNA damage induced by reactive oxygen species can be measured in saliva. Clinical studies have shown an association with oral pathologies at least for some of the established salivary markers of oxidative stress. This association is currently limited to the population level and none of the widely used markers can be applied for individual diagnostics. Oxidative stress seems to be of local oral origin, but it is currently unclear whether it is caused by an overproduction of reactive oxygen species due to inflammation or by the lack of antioxidants. Interventional studies, both, in experimental animals as well as humans indicate that antioxidant treatment could prevent or slow-down the progress of periodontitis. This makes the potential clinical use of salivary markers of oxidative stress even more attractive. This review summarizes basic information on the most commonly used salivary markers of oxidative damage, antioxidant status, and carbonyl stress and the studies analyzing these markers in patients with caries or periodontitis.

Analyses of Gingival Adhesion Molecules in Periodontitis: Theoretical In Silico, Comparative In Vivo, and Explanatory In Vitro Models

BACKGROUND

A deeper understanding of periodontitis pathophysiology is central to future development of novel biomarkers and therapeutics. The following is reported here: 1) an in silico network model of interactions among cell adhesion molecules and a network-focused microarray analysis of the corresponding genes in periodontitis; 2) analysis of secretions of adhesion molecules in gingival tissue samples from patients with periodontitis and healthy controls; and 3) effect of the human neutrophilic peptide-1 (HNP-1) on epithelial adhesion molecules.

METHODS

The network model identified 85 nodes in relation to the interactions of adhesion molecules. Subsequently, the relative gene expression was overlaid on the network model. Differential gene expression was analyzed, and false discovery rate control was performed for statistical assessment of the microarray data. Both tissue and cell culture samples were immunostained for desmocollin (DSC)2, occludin (OCLN), desmoglein (DSG)1, tight junction protein 2, and gap junction protein α.

RESULTS

The differential gene expression analysis revealed that the epithelial adhesion molecules were significantly lower in abundance in individuals with periodontitis than controls. In contrast, the genes for leukocyte adhesion molecules showed a significant upregulation. Immunostainings revealed elevated secretions of both DSG1 and OCLN in periodontitis. An in vitro model suggested reduced DSC2 and OCLN secretions in the presence of HNP-1.

CONCLUSIONS

Gene expression of gingival adhesion molecules in periodontitis is regulated by leukocyte transmigration, whereas the neutrophilic antimicrobial peptide HNP-1 is noted as a putative regulator of epithelial adhesion molecules. These observations contribute to the key mechanisms by which future biomarkers might be developed for periodontitis.