Identification of a novel salivary biomarker miR-143-3p for periodontal diagnosis: A proof of concept study

Expression of miRNAs (146a and 155) in human peri-implant tissue affected by peri-implantitis: a case control study

BACKGROUND

In literature, the levels of miRNA-146a and miRNA-155 are increased in periodontitis. Limited data are available regarding the expression of miRNA-146a and miR-NA-155 in diseased human peri-implant tissue. Therefore, the objective of this study was to explore the expression of miRNA-146a and miRNA-155 in human gingival peri-implant tissue affected by peri-implantitis.

METHODS

After recording the clinical parameters, human peri-implant pocket tissues were harvested from sites diagnosed with peri-implantitis (n = 15 cases) in addition to healthy peri-implant sulcus tissues (n = 15 controls). The levels of miRNA-146a and miRNA-155 were assessed using real-time qPCR.

RESULTS

Cases exhibited a significantly higher mean expression of miRNA-155 (5.2-fold increase) and miRNA-146a (2.8-fold increase) than controls. MiRNA-155 and miRNA-146a demonstrated an appropriate sensitivity (87.5% and 87.5%, respectively) and specificity (73.3% and 66.7%, respectively) in discriminating cases from controls. A moderate correlation (r = 0.544, p = 0.029) was found between miRNA-155 and miRNA-146a levels in the case group.

CONCLUSIONS

The expressions of miRNA-146a and miR-NA-155 are different between healthy and peri-implantitis affected tissues. Both miRNAs might potentially able to discriminate healthy from peri-implantitis affected tissues.

Salivary fructosamine in diabetic and non-diabetic individuals with healthy and diseased periodontium and its changes after non-surgical periodontal therapy

AIMS

A bidirectional relationship has been reported between diabetes mellitus and periodontitis. The present study aimed to estimate salivary fructosamine in diabetic and non-diabetic individuals with healthy and diseased periodontium and to measure its changes after non-surgical periodontal therapy. Another aim was to identify the cut-off value of salivary fructosamine to diagnose diabetes mellitus and to correlate it with glycated hemoglobin.

METHODS

Salivary fructosamine and HbA1c were assessed in periodontally healthy individuals and periodontitis patients (n = 60 in each group). Both groups comprised of equal number of patients with and without diabetes mellitus. Salivary fructosamine estimation was repeated 4 weeks after non-surgical periodontal therapy in periodontitis patients.

RESULTS

HbA1c and Salivary fructosamine were significantly higher in the periodontally diseased compared to the healthy group. Significantly higher values of these biomarkers were noticed in diabetic patients with periodontitis compared to the non-diabetic group. Periodontal therapy significantly reduced salivary fructosamine in both diabetic and nondiabetic periodontitis patients. A significant positive high correlation was noticed between salivary fructosamine and HbA1c (r = 0.76). The cut-off value of salivary fructosamine was found to be 68 µg/mL with 95% sensitivity, 81.67% specificity, 83.82% positive predictive value, and 94.23% negative predictive value.

CONCLUSION

Periodontitis can contribute to glycemic control and periodontal therapy can bring about improvement in glycemic status. Salivary fructosamine could be used as an alternate glycemic biomarker and its advantages over HbA1c include simple and non-invasive collection of saliva and it can provide intermediate glycemic status.

CLINICAL TRIAL REGISTRY OF INDIA

2020/11/038496.

Sample-to-answer salivary miRNA testing: New frontiers in point-of-care diagnostic technologies

MicroRNA (miRNA), crucial non-coding RNAs, have emerged as key biomarkers in molecular diagnostics, prognosis, and personalized medicine due to their significant role in gene expression regulation. Salivary miRNA, in particular, stands out for its non-invasive collection method and ease of accessibility, offering promising avenues for the development of point-of-care diagnostics for a spectrum of diseases, including cancer, neurodegenerative disorders, and infectious diseases. Such development promises rapid and precise diagnosis, enabling timely treatment. Despite significant advancements in salivary miRNA-based testing, challenges persist in the quantification, multiplexing, sensitivity, and specificity, particularly for miRNA at low concentrations in complex biological mixtures. This work delves into these challenges, focusing on the development and application of salivary miRNA tests for point-of-care use. We explore the biogenesis of salivary miRNA and analyze their quantitative expression and their disease relevance in cancer, infection, and neurodegenerative disorders. We also examined recent progress in miRNA extraction, amplification, and multiplexed detection methods. This study offers a comprehensive view of the development of salivary miRNA-based point-of-care testing (POCT). Its successful advancement could revolutionize the early detection, monitoring, and management of various conditions, enhancing healthcare outcomes. This article is categorized under: Diagnostic Tools > Biosensing Diagnostic Tools > Diagnostic Nanodevices.

Emerging Role of miRNAs in the Pathogenesis of Periodontitis

MicroRNAs (miRNAs) have been found to participate in the pathogenesis of several immune-related conditions through the modulation of the expression of cytokine coding genes and other molecules that affect the activity of the immune system. Periodontitis is an example of these conditions associated with the dysregulation of several miRNAs. Several miRNAs such as let-7 family, miR-125, miR-378, miR-543, miR-302, miR-214, miR-200, miR-146, miR-142, miR-30 and miR-21 have been shown to be dysregulated in patients with periodontitis. miR-146 is the most assessed miRNA in these patients, which is up-regulated in most studies in patients with periodontitis. In the present review, we describe the impact of miRNAs dysregulation on the pathoetiology of periodontitis.

Unique miRomics Expression Profiles in Tannerella forsythia-Infected Mandibles during Periodontitis Using Machine Learning

T. forsythia is a subgingival periodontal bacterium constituting the subgingival pathogenic polymicrobial milieu during periodontitis (PD). miRNAs play a pivotal role in maintaining periodontal tissue homeostasis at the transcriptional, post-transcriptional, and epigenetic levels. The aim of this study was to characterize the global microRNAs (miRNA, miR) expression kinetics in 8- and 16-week-old T. forsythia-infected C57BL/6J mouse mandibles and to identify the miRNA bacterial biomarkers of disease process at specific time points. We examined the differential expression (DE) of miRNAs in mouse mandibles (n = 10) using high-throughput NanoString nCounter® miRNA expression panels, which provided significant advantages over specific candidate miRNA or pathway analyses. All the T. forsythia-infected mice at two specific time points showed bacterial colonization (100%) in the gingival surface, along with a significant increase in alveolar bone resorption (ABR) (p < 0.0001). We performed a NanoString analysis of specific miRNA signatures, miRNA target pathways, and gene network analysis. A total of 115 miRNAs were DE in the mandible tissue during 8 and 16 weeks The T. forsythia infection, compared with sham infection, and the majority (99) of DE miRNAs were downregulated. nCounter miRNA expression kinetics identified 67 downregulated miRNAs (e.g., miR-375, miR-200c, miR-200b, miR-34b-5p, miR-141) during an 8-week infection, whereas 16 upregulated miRNAs (e.g., miR-1902, miR-let-7c, miR-146a) and 32 downregulated miRNAs (e.g., miR-2135, miR-720, miR-376c) were identified during a 16-week infection. Two miRNAs, miR-375 and miR-200c, were highly downregulated with >twofold change during an 8-week infection. Six miRNAs in the 8-week infection (miR-200b, miR-141, miR-205, miR-423-3p, miR-141-3p, miR-34a-5p) and two miRNAs in the 16-week infection (miR-27a-3p, miR-15a-5p) that were downregulated have also been reported in the gingival tissue and saliva of periodontitis patients. This preclinical in vivo study identified T. forsythia-specific miRNAs (miR-let-7c, miR-210, miR-146a, miR-423-5p, miR-24, miR-218, miR-26b, miR-23a-3p) and these miRs have also been reported in the gingival tissues and saliva of periodontitis patients. Further, several DE miRNAs that are significantly upregulated (e.g., miR-101b, miR-218, miR-127, miR-24) are also associated with many systemic diseases such as atherosclerosis, Alzheimer's disease, rheumatoid arthritis, osteoarthritis, diabetes, obesity, and several cancers. In addition to DE analysis, we utilized the XGBoost (eXtreme Gradient boost) and Random Forest machine learning (ML) algorithms to assess the impact that the number of miRNA copies has on predicting whether a mouse is infected. XGBoost found that miR-339-5p was most predictive for mice infection at 16 weeks. miR-592-5p was most predictive for mice infection at 8 weeks and also when the 8-week and 16-week results were grouped together. Random Forest predicted miR-592 as most predictive at 8 weeks as well as the combined 8-week and 16-week results, but miR-423-5p was most predictive at 16 weeks. In conclusion, the expression levels of miR-375 and miR-200c family differed significantly during disease process, and these miRNAs establishes a link between T. forsythia and development of periodontitis genesis, offering new insights regarding the pathobiology of this bacterium.

Salivary microRNAs as innovative biomarkers for early diagnosis of oral diseases: a comparison of conventional cigarette smokers and tobacco heating system 2.2 users

BACKGROUND

MicroRNAs (miRNAs) are considered valid prognostic and diagnostic biomarkers. The different miRNA expression profiles in cancer cells compared to normal cells make them potential biomarkers used for the early diagnosis of oral diseases. Following exposure to cigarette smoking, miRNA altered profile expression is associated with resistance mechanisms against anticancer therapies. Cellular models showed a reduced human gingival epithelium alteration after exposure to THS2.2 and a lower pathogenicity than 3R4F CS. The aim of the study was to compare the expression of saliva miRNA profile of THS2.2 and 3R4F CS users compared to patients not exposed to the risk factor and to identify and study the modulation of miRNAs associated with the development of oral diseases. In particular, we will focus on the analysis of a group of miRNAs know to be involved in the development of smoking-related diseases.

METHODS

The study will be performed in 18 months and dentists and biochemists will be involved in the different phases. To perform the study, healthy volunteers, including smokers of THS2.2 or 3R4F CS, will be enrolled.

RESULTS

The samples will be collected from 3 experimental groups, each consisting of 30 subjects: group 1 (no smoking subjects), group 2 (subjects exposed to THS2.2), group 3 (subjects exposed to 3R4F CS). The collection of the saliva sample will be conducted in a standardized way. Following the collection, saliva will be processed.

CONCLUSIONS

Previous studies have suggested that miRNAs are prognostic biomarkers for various smoking-related diseases. Based on the post-transcriptional regulation of some mRNAs connected to different oral pathologies, we expect a specific miRNA-mRNA interaction, which could be a starting point for the development of new possible diagnostic, therapeutic and prognostic approaches.

Changes in the components of salivary exosomes due to initial periodontal therapy

PURPOSE

Exosomes are membrane vesicles that are present in body fluids and contain proteins, lipids, and microRNA (miRNA). Periodontal tissue examinations assess the degree of periodontal tissue destruction according to the probing depth (PD), clinical attachment loss (CAL), bleeding on probing, and X-ray examinations. However, the accurate evaluation of the prognosis of periodontitis is limited. In this study, we collected saliva from patients before and after initial periodontal therapy (IPT) and compared changes in the clinical parameters of periodontitis with changes in the components of salivary exosomes.

METHODS

Saliva was collected from patients with stage III and IV periodontitis at the first visit and post-IPT. Exosomes were purified from the saliva, and total protein and RNA were extracted. Changes in expression levels of C6, CD81, TSG101, HSP70, and 6 kinds of miRNA were analyzed by western blots and real-time polymerase chain reaction.

RESULTS

Patients with increased C6 expression after IPT had significantly higher levels of periodontal inflamed surface area (PISA), miR-142, and miR-144 before and after IPT than patients with decreased C6 expression after IPT. Patients with decreased and unchanged CD81 expression after IPT showed significantly higher PD, CAL, and PISA before IPT than after IPT. Patients with decreased and unchanged TSG101 expression after IPT had significantly higher PD before IPT than after IPT. Patients with increased HSP70 expression after IPT had significantly higher PD and PISA before and after IPT than patients with unchanged HSP70 after IPT. The expression levels of miR-142, miR-144, miR-200b, and miR-223 changed with changes in the levels of C6, CD81, TSG101, and HSP70 in the salivary exosomes of periodontitis patients before and after IPT.

CONCLUSIONS

The expression levels of proteins and miRNAs in salivary exosomes significantly changed after IPT in periodontitis patients, suggesting that the components of exosomes could serve as biomarkers for periodontitis.

Oral Spirochete Treponema denticola Intraoral Infection Reveals Unique miR-133a, miR-486, miR-126-3p, miR-126-5p miRNA Expression Kinetics during Periodontitis

miRNAs are major regulators of eukaryotic gene expression and host immunity, and play an important role in the inflammation-mediated pathways in periodontal disease (PD) pathogenesis. Expanding our previous observation with the global miRNA profiling using partial human mouth microbes, and lack of in vivo studies involving oral spirochete Treponema denticola-induced miRNAs, this study was designed to delineate the global miRNA expression kinetics during progression of periodontitis in mice infected with T. denticola by using NanoString nCounter® miRNA panels. All of the T. denticola-infected male and female mice at 8 and 16 weeks demonstrated bacterial colonization (100%) on the gingival surface, and an increase in alveolar bone resorption (p < 0.0001). A total of 70 miRNAs with at least 1.0-fold differential expression/regulation (DE) (26 upregulated and 44 downregulated) were identified. nCounter miRNA expression profiling identified 13 upregulated miRNAs (e.g., miR-133a, miR-378) and 25 downregulated miRNAs (e.g., miR-375, miR-34b-5p) in T. denticola-infected mouse mandibles during 8 weeks of infection, whereas 13 upregulated miRNAs (e.g., miR-486, miR-126-5p) and 19 downregulated miRNAs (miR-2135, miR-142-3p) were observed during 16 weeks of infection. One miRNA (miR-126-5p) showed significant difference between 8 and 16 weeks of infection. Interestingly, miR-126-5p has been presented as a potential biomarker in patients with periodontitis and coronary artery disease. Among the upregulated miRNAs, miR-486, miR-126-3p, miR-126-5p, miR-378a-3p, miR-22-3p, miR-151a-3p, miR-423-5p, and miR-221 were reported in human gingival plaques and saliva samples from periodontitis and with diabetes. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed various functional pathways of DE miRNAs, such as bacterial invasion of epithelial cells, Ras signaling, Fc gamma R-mediated phagocytosis, osteoclast differentiation, adherens signaling, and ubiquitin mediated proteolysis. This is the first study of DE miRNAs in mouse mandibles at different time-points of T. denticola infection; the combination of three specific miRNAs, miR-486, miR-126-3p, and miR-126-5p, may serve as an invasive biomarker of T. denticola in PD. These miRNAs may have a significant role in PD pathogenesis, and this research establishes a link between miRNA, periodontitis, and systemic diseases.

Oral pathogen aggravates atherosclerosis by inducing smooth muscle cell apoptosis and repressing macrophage efferocytosis

Periodontitis imparting the increased risk of atherosclerotic cardiovascular diseases is partially due to the immune subversion of the oral pathogen, particularly the Porphyromonas gingivalis (P. gingivalis), by inducing apoptosis. However, it remains obscure whether accumulated apoptotic cells in P. gingivalis-accelerated plaque formation are associated with impaired macrophage clearance. Here, we show that smooth muscle cells (SMCs) have a greater susceptibility to P. gingivalis-induced apoptosis than endothelial cells through TLR2 pathway activation. Meanwhile, large amounts of miR-143/145 in P.gingivalis-infected SMCs are extracellularly released and captured by macrophages. Then, these miR-143/145 are translocated into the nucleus to promote Siglec-G transcription, which represses macrophage efferocytosis. By constructing three genetic mouse models, we further confirm the in vivo roles of TLR2 and miR-143/145 in P. gingivalis-accelerated atherosclerosis. Therapeutically, we develop P.gingivalis-pretreated macrophage membranes to coat metronidazole and anti-Siglec-G antibodies for treating atherosclerosis and periodontitis simultaneously. Our findings extend the knowledge of the mechanism and therapeutic strategy in oral pathogen-associated systemic diseases.

MicroRNA-28-5p as a potential diagnostic biomarker for chronic periodontitis and its role in cell proliferation and inflammatory response

Background/purpose

Recent studies have pointed to the crucial role of microRNAs (miRNAs) in chronic periodontitis (CP). This study investigated the regulation and potential mechanisms of miR-28-5p in CP patients and lipopolysaccharide (LPS)-induced periodontal ligament cells (PDLCs).

Materials and methods

76 CP patients and 71 periodontally healthy subjects were included. RT-qPCR was employed to examine miR-28-5p and sphingosine kinase −1 (SPHK1) in subjects’ gingival sulcus fluid and PDLCs. The diagnostic performance was evaluated by measuring the area under the curve (AUC) of the receiver operating characteristic (ROC) analysis. Pearson correlation coefficient (r) was adopted to explore the statistical relation between indicators. PDLCs proliferation and inflammation factors were determined by CCK-8 and ELISA assay. The direct target gene was validated by a dual-luciferase reporter assay.

Results

miR-28-5p was lowly expressed in CP patients and LPS-induced PDLCs (P < 0.05). AUC for miR-28-5p was 0.937, which had certain diagnostic value. Additionally, miR-28-5p was negatively correlated with periodontal clinical indicators and inflammatory factors. Cell proliferation of PDLCs was inhibited and inflammation was promoted under LPS induction, however, elevated miR-28-5p diminished the effect of LPS (P < 0.05). SPHK1 acts as a miR-28-5p target and the elevation of SPHK1 caused by LPS treatment was inhibited by the increased miR-28-5p.

Conclusion

Present study revealed that miR-28-5p could be served as a potential diagnostic biomarker for CP. And miR-28-5p may participate in CP progression by targeting SPHK1 to regulate the proliferation and inflammation of PDLCs. This study may offer insights into CP treatment and diagnosis.

Next generation sequencing-based salivary biomarkers in oral squamous cell carcinoma

Selection of potential disease-specific biomarkers from saliva or epithelial tissues through next generation sequencing (NGS)-based protein studies has recently become possible. The early diagnosis of oral squamous cell carcinoma (OSCC) has been difficult, if not impossible, until now due to the lack of an effective OSCC biomarker and efficient molecular validation method. The aim of this study was to summarize the advances in the application of NGS in cancer research and to propose potential proteomic and genomic saliva biomarkers for NGS-based study in OSCC screening and diagnosis programs. We have reviewed four categories including definitions and use of NGS, salivary biomarkers and OSCC, current biomarkers using the NGS-based technique, and potential salivary biomarker candidates in OSCC using NGS.

MicroRNAs and periodontal disease: a qualitative systematic review of human studies

Purpose

MicroRNAs (miRNAs) are epigenetic post-transcriptional regulators that modulate gene expression and have been identified as biomarkers for several diseases, including cancer. This study aimed to systematically review the relationship between miRNAs and periodontal disease in humans, and to evaluate the potential of miRNAs as diagnostic and prognostic biomarkers of disease.

Methods

The review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines (reference number CRD42020180683). The MEDLINE, Scopus, Cochrane Library, Embase, Web of Science, and SciELO databases were searched for clinical studies conducted in humans investigating periodontal diseases and miRNAs. Expression levels of miRNAs across the different groups were analysed using the collected data.

Results

A total of 1,299 references were identified in the initial literature search, and 23 articles were finally included in the review. The study designs were heterogeneous, which prevented a meta-analysis of the data. Most of the studies compared miRNA expression levels between patients with periodontitis and healthy controls. The most widely researched miRNA in periodontal diseases was miR-146a. Most studies reported higher expression levels of miR-146a in patients with periodontitis than in healthy controls. In addition, many studies also focused on identifying target genes of the differentially expressed miRNAs that were significantly related to periodontal inflammation.

Conclusions

The results of the studies that we analysed are promising, but diagnostic tests are needed to confirm the use of miRNAs as biomarkers to monitor and aid in the early diagnosis of periodontitis in clinical practice.

MicroRNA expression profiles in peri-miniscrew implant crevicular fluid in orthodontics: a pilot study

Background

This study systematically evaluated microRNA (miRNA) expression patterns in peri-miniscrew implant crevicular fluid (PMICF) in orthodontic patients.

Methods

Next-generation sequencing (NGS) was performed to obtain miRNA profiles in PMICF or gingival crevicular fluid (GCF) collected from 3 healthy volunteers (H), 3 peri-implantitis patients (PMSII) and 5 periodontitis patients (P). MiRNA expression patterns were compared between normal and orthodontic PMICF and GCF. Differentially expressed miRNAs were estimated by quantitative real-time PCR (qRT-PCR). Enrichment analyses of the gene targets controlled by these miRNAs were conducted by Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses.

Results

Compared with healthy donors, in PMSII patients, a total of 206 upregulated miRNAs and 152 downregulated miRNAs were detected in PMICF, while periodontitis patients had 333 upregulated miRNAs and 318 downregulated miRNAs. MiR-544a, miR-1245b-3p, miR-1825, miR-4291, miR-3689e, and miR-4477a were chosen randomly for further examination. qRT-PCR examination confirmed that the expression levels of miR-1245b-3p and miR-4291 were higher in PMSII than in H samples and that the expression levels of miR-1825 were higher in PMSII than in P samples. However, contrary to the NGS results, qRT-PCR analysis showed decreased expression of miR544a in PMSII. MiR3689e and miR4477a expression did not differ significantly among all samples. According to GO and KEGG pathway analyses of miR-1825, miR-4291, and miR-1245b-3p high enrichment of target genes involved in the PI3K-AKT signalling pathway was observed.

Conclusions

The NGS analysis of normal and orthodontic PMICF/CGF showed different miRNA profiles, which may lay the foundation for future research on the molecular mechanism of PMSII. miR-4291, miR-1245b-3p and miR-1825 may be used as diagnostic markers and potential therapeutic targets for PMSII.

The miR-223-3p Regulates Pyroptosis Through NLRP3-Caspase 1-GSDMD Signal Axis in Periodontitis

Salivary exosomes contain various components and may play important roles in oral diseases. The purpose of this study was to verify the possible function of miR-223-3p from salivary exosomes in periodontitis. We isolated the salivary exosomes and found that the miR-223-3p content of salivary exosomes from periodontitis was less than the healthy control. Furthermore, we performed dual-luciferase reporter assay and real-time PCR to verify that (NOD)-like receptor (NLR) pyrin domain-containing 3 (NLRP3) was the target of miR-223-3p. When we knocked down the miR-223-3p expression in THP-1-derived macrophages, the expression of NLRP3 and the downstream inflammatory mediators interleukin-1β (IL-1β) and IL-6 were upregulated. By using integrated bioinformatics analysis, we found that pyroptosis and cytokine secretion participated in inflammatory gingival tissues. In addition, NLRP3, and the pyroptosis executioner, gasdermin D (GSDMD) was highly active in inflammatory gingival tissues compared with healthy controls by western blotting and immunohistochemistry. In summary, we speculated that miR-223-3p in salivary exosomes might regulate GSDMD-mediated pyroptosis by targeting NLRP3 in periodontitis. Detection of miR-223-3p expression in salivary exosomes could be used as an important non-invasive method to diagnose and evaluate the severity of periodontitis.

hsa-miR-374b-5p regulates expression of the gene U2AF homology motif (UHM) kinase 1

OBJECTIVE

We aimed to identify a microRNA (miRNA) that is significantly upregulated in blood and in cells of the oral mucosa upon exposure to the periodontitis main risk factors oral inflammation and tobacco smoke, to subsequently identify its target gene and to describe the molecular mechanism of gene regulation.

BACKGROUND

miRNAs are associated with many disorders. Array-based miRNA expression studies indicated a number of differentially expressed miRNAs in the pathology of oral diseases. However, these miRNAs mostly lacked replication, and their target genes have remained unknown.

METHODS

863 miRNAs were analyzed in blood from 18 PD cases and 70 controls (Geniom Biochip). Selected miRNAs were analyzed for upregulation in the inflamed oral mucosa of PD patients using published miRNA expression profiling studies from gingival cells. hsa-miR-374b-5p mimic was overexpressed in primary gingival fibroblasts (pGFs) from 3 donors, and genome-wide mRNA expression was quantified (Clarion Array). Gene-specific regulation was validated by qRT-PCR and Luciferase activity in HeLa cells.

RESULTS

hsa-miR-374b-5p showed >twofold change (FC) in 3 independent studies performed in blood, gingival tissues, and cells. After hsa-miR-374b-5p overexpression, genome-wide expression analysis showed UHMK1 as top 1 downregulated gene in pGFs (p = 2.5 × 10^-04 , fold change = -1.8). Reporter genes demonstrated that hsa-miR-374b-5p downregulates mRNA levels (p = .02; FC = -1.5), leading to reduction in protein activity (p = .013, FC = -1.3).

CONCLUSIONS

hsa-miR-374b-5p is upregulated in blood and ginvial cells exposed to oral inflammation and tobacco smoke and regulates UHMK1, which has a role in osteoclast differentiation.

Analysis of periodontitis-associated miRNAs in gingival tissue, gingival crevicular fluid, saliva and blood plasma

OBJECTIVE

Periodontitis (PD) is a chronic inflammatory disease which is associated with multiple systemic comorbidities, including rheumatoid arthritis (RA), meanwhile the etiopathology of PD may be modulated by various factors including microRNA (miRNA). The present study aimed to reveal miRNAs associated with PD in gingival tissue, gingival crevicular fluid (GCF), saliva, plasma and to assess the possible influence of RA.

DESIGN

The cross-sectional study included 30 patients with PD and 31 periodontally healthy participants. A total of 25 participants were additionally diagnosed with RA. Microarray analysis of eight gingival tissue samples was performed and four PD-associated miRNAs were selected: miR-199a-5p, miR-483-5p, miR-3198 and miR-4299. Target miRNAs were further assessed by means of RT-qPCR in 61 gingival tissue samples and corresponding bodily fluids - GCF, saliva and plasma.

RESULTS

The upregulation of miR-199a-5p and downregulation of miR-4299 in gingival tissue was associated with the presence of PD and RA (P < 0.05). GCF level of miR-3198 was higher amongst participants with PD (P = 0.019) and showed a good diagnostic ability (AUC = 0.72, P = 0.008). Increased miR-199a-5p salivary level and decreased miR-199a-5p plasma level were observed amongst patients with worse clinical status of PD (P < 0.05). MiR-3198 and miR-4299 combination in GCF demonstrated AUC value of 0.86 and reached sensitivity of 68 % and specificity of 96 %.

CONCLUSIONS

Aberrant expression of miR-199a-5p, miR-483-5p, miR-3198, miR-4299 in gingival tissues is associated with the presence and/or severity of PD. MiR-3198, miR-4299 level in GCF and miR-199a-5p level in plasma strongly correlated with PD, demonstrating significant diagnostic performance.

Association of periodontitis and tooth loss with liver cancer: A systematic review

A number of epidemiological studies have suggested a positive association between periodontal diseases and oro-digestive cancers, including liver cancer. The purpose of the present systematic review was to analyze the current evidence regarding the potential association between periodontitis and/or tooth loss and the risk of liver cancer. A comprehensive search of PubMed, Scopus and Web of Science databases was conducted in August 2019. The inclusion criteria comprised all observational studies that assessed the relationship between periodontitis or tooth loss and liver cancer. Case reports, animal studies, experimental studies, and reviews were excluded. Due to great heterogeneity among the included studies, no meta-analysis was conducted. Six studies (five prospective cohorts and one case-control) comprising 619,834 subjects (including 916 liver cancer cases) were included. The studies were conducted in the United States, Europe, and Asia. Three large-scale cohort studies reported a positive association between periodontitis or tooth loss and the risk of liver cancer. One case-control study found some association between liver cancer and loss of 12-23 teeth, but such association was not replicated in patients with greater number of tooth loss. Contrarily, two studies failed to report any association between periodontitis and/or tooth loss and the risk of liver cancer. The available evidence suggests a possible link between tooth loss/periodontitis and the risk of liver cancer. However, the evidence is not conclusive enough, a fact that drives to conduct more, well-designed, prospective cohort studies to further explore the potential association between periodontitis and the risk of liver cancer.

Expression of MicroRNAs in Periodontal Disease: A Systematic Review

Introduction

Periodontal disease (PD) is a chronic inflammation of the soft tissues that support the structure of the tooth, and miRNAs are highly dynamic molecules that participate in the regulation of gene expression interfering with multiple genetic targets. The dysregulation of the expression of miRNAs has been associated with different types of pathologies; therefore, they are excellent molecules to be studied as biomarkers. Material and Methods. A search was made in the electronic databases of PubMed, Scopus, and Science Direct. The following key words were used: “microRNAs,” “miRNAs,” “periodontal disease,” “periodontitis,” and “biomarker”; employee independent search strategies with the Boolean operators “OR” and “AND”; a further search of the references of the selected studies was performed to detect potential studies that met the selection criteria. The data recollected from each article were author, country, year of publication, sample size, type of sample used to identify miRNAs, methodology used to identify miRNAs, type of periodontal disease, and miRNAs identified.

Results

Of the 13 selected studies, 6 used gingival tissue as a sample for the identification of miRNAs, 3 used gingival fluid, 2 used saliva, 1 used serum, and another used periodontal tissue. Chronic periodontitis was the most studied periodontal disease in 9 of the 13 selected articles; 7 used microarrays as the main technique for the identification of miRNAs. qRT-PCR was the assay choice to validate the identified miRNAs.

Conclusion

The main type of periodontal disease on which most studies are focused is chronic periodontitis, with the main miRNAs being hsa-miR-146a, hsa-miR-146b, hsa-miR-155, and hsa-miR-200. This systematic review is one of the first to carry out an analysis of the current role of miRNAs in PD as biomarkers.

Effect of Periodontitis and Scaling and Root Planing on Risk of Pharyngeal Cancer: A Nested Case-Control Study

This study investigated the association between periodontitis and the risk of pharyngeal cancer in Taiwan. For this population-based nested case–control study using the Longitudinal Health Insurance Database derived from Taiwan’s National Health Insurance Research Database, we identified patients (n = 1292) who were newly diagnosed with pharyngeal cancer between 2005 and 2013 and exactly paired them with propensity score matched control subjects (n = 2584). Periodontitis and scaling and root planing (SRP) were identified before the index date. Pharyngeal cancer was subdivided into 3 subgroups on the basis of anatomic location: nasopharyngeal cancer, oropharyngeal cancer, and hypopharyngeal cancer. A multiple conditional logistic regression model was applied to analyze the adjusted odds ratio (aOR). Periodontitis was associated with an increased risk of pharyngeal cancer (aOR, 1.57; 95% confidence interval (CI), 1.17 to 2.10), especially oropharyngeal cancer (aOR, 2.22; 95% CI, 1.07 to 4.60). We found a decreased risk of pharyngeal cancer in patients who had undergone SRP (aOR, 0.77; 95% CI, 0.61 to 0.96). In conclusion, this study showed that periodontitis was associated with an increased risk of pharyngeal cancer and SRP exerted a protective effect against pharyngeal cancer. Our results suggest that treating periodontitis and performing SRP, which are modifiable factors in oral health, in clinical practice may provide an opportunity to decrease the disease burden of pharyngeal cancer in Taiwan.

Development of an miRNA-Array-Based Diagnostic Signature for Periodontitis

Periodontitis progression is accompanied by irreversible alveolar bone absorption and leads to tooth loss. Early diagnosis is important for tooth stability and periodontal tissue preservation. However, there is no recognized miRNA diagnostic signature with convincing sensitivity and specificity for periodontitis. In this study, we obtained miRNA array expression profiles of periodontitis from the Gene Expression Omnibus (GEO) database. After screening for differentially expressed miRNAs, the least absolute shrinkage and selection operator (LASSO) method was performed to identify and construct a 17-miRNA-based diagnostic signature (hsa-miR-3917, hsa-mir-4271, hsa-miR-3156, hsa-miR-3141, hsa-miR-1246, hsa-miR-125a-5p, hsa-miR-671-5p, hcmv-mir-UL70, hsa-miR-650, hsa-miR-497-3p, hsa-miR-145-3p, hsa-miR-141-3p, hsa-miR-210-3p, hsa-miR-204-3p, hsa-miR-203a-5p, hsa-miR-99a-3p, and hsa-miR-30a-3p). Periodontal tissue samples with higher risk scores were more likely to show symptoms of periodontitis. Then, the receiver operating characteristic (ROC) curves were used to assess the diagnostic value of the miRNA signature, which indicated that the optimum cutoff value in periodontitis diagnosis was 0.5056 with an area under the ROC curve (AUC) of 0.996, a sensitivity of 97.3%, a specificity of 100.0% in the training cohort; in the testing cohort, the corresponding values were as follows: an AUC of 0.998, a sensitivity of 97.9%, and a specificity of 91.7%. We next evaluated the efficacy of the signature in differentiating disease subtype and affected range. Furthermore, we conducted functional enrichment analysis of the 17 miRNA-targeted mRNAs, including the regulation of mTOR activity and cell autophagy, Th1/Th2 cell balance and immunoregulation, cell apoptosis, and so on. In summary, our study identified and validated a 17-miRNA diagnostic signature with convincing AUC, sensitivity, and specificity for periodontitis.

microRNAs in inflammatory alveolar bone defect: A review

Inflammatory alveolar bone defects are caused by periodontal pathogens, are one of the most common oral diseases in the clinic, and are characterized by periodontal support tissue damage. MicroRNAs (miRNAs) can participate in a variety of inflammatory lesions and modulate bone metabolism through the posttranscriptional regulation of target genes. In recent years, studies have confirmed that some miRNAs play significant roles in the development of inflammatory alveolar bone defects. Therefore, we reviewed the correlation between miRNAs and inflammatory alveolar bone defects and elucidated the underlying mechanisms to provide new ideas for the prevention and treatment of inflammatory alveolar bone defects.

Immune landscape of periodontitis unveils alterations of infiltrating immunocytes and molecular networks-aggregating into an interactive web-tool for periodontitis related immune analysis and visualization

Background

Immunity reaction plays an essential role in periodontitis progress and we aim to investigate the underlying regulatory network of immune reactions in periodontitis.

Methods

CIBERSORT was used to estimate immunocyte fractions in different clinical statuses. Logistic regression was used to assess the immunocyte weight in periodontitis. Immune-related periodontitis subtypes were identified by the Nonnegative Matrix Factorization algorithm. Gene-set enrichment analysis and Gene-set variation analysis were conducted to analyze pathway activities. Immunocytes related gene modules were identified by Weighted gene co-expression network analysis.

Results

Altered immunocytes in healthy versus periodontitis, aggressive versus chronic, male versus female and age were identified. Immunocytes enriched in periodontitis were calculated, and their correlation was also explored. Two distinct immune-related periodontitis subtypes were identified and one is characterized by B cell reactions and the other is IL-6 cytokine reactions. 463 statistically significant correlations between 22 immunocytes and pathways were revealed. Immunocytes and clinical phenotypes matched their gene modules, and their functions were annotated. Last, an easy-to-use and user-friendly interactive web-tool were developed for periodontitis related immune analysis and visualization (https://118.24.100.193:3838/tool-PIA/).

Conclusions

This study systematically investigated periodontitis immune atlas and caught a glimpse of the underlying mechanism of periodontitis from gene-pathway-immunocyte networks, which can not only inspire researchers but also help them in periodontitis related immune researches.

Biosensor and Lab-on-a-chip Biomarker-identifying Technologies for Oral and Periodontal Diseases

Periodontitis is a complex multifactorial disease that can lead to destruction of tooth supporting tissues and subsequent tooth loss. The most recent global burden of disease studies highlight that severe periodontitis is one of the most prevalent chronic inflammatory conditions affecting humans. Periodontitis risk is attributed to genetics, host-microbiome and environmental factors. Empirical diagnostic and prognostic systems have yet to be validated in the field of periodontics. Early diagnosis and intervention prevents periodontitis progression in most patients. Increased susceptibility and suboptimal control of modifiable risk factors can result in poor response to therapy, and relapse. The chronic immune-inflammatory response to microbial biofilms at the tooth or dental implant surface is associated with systemic conditions such as cardiovascular disease, diabetes or gastrointestinal diseases. Oral fluid-based biomarkers have demonstrated easy accessibility and potential as diagnostics for oral and systemic diseases, including the identification of SARS-CoV-2 in saliva. Advances in biotechnology have led to innovations in lab-on-a-chip and biosensors to interface with oral-based biomarker assessment. This review highlights new developments in oral biomarker discovery and their validation for clinical application to advance precision oral medicine through improved diagnosis, prognosis and patient stratification. Their potential to improve clinical outcomes of periodontitis and associated chronic conditions will benefit the dental and overall public health.

The Impact of Diet, Nutrition and Nutraceuticals on Oral and Periodontal Health

Oral and periodontal diseases can determine severe functional, phonatory and aesthetic impairments and are the main cause of adult tooth loss. They are caused by some specific bacteria that provoke an intense local inflammatory response and affect-with particular gravity-susceptible subjects, because of reasons related to genetics and lifestyles (e.g., smoking and home oral hygiene habits). They are more frequent in the disadvantaged segments of society and, in particular, in subjects who have difficulty accessing preventive services and dental care. Some systemic diseases, such as uncontrolled diabetes, can increase their risk of development and progression. Recently, in addition to the obvious considerations of severe alterations and impairments for oral health and well-being, it has been noted that periodontitis can cause changes in the whole organism. Numerous clinical and experimental studies have highlighted the presence of a strong association between periodontitis and some systemic diseases, in particular, cardiovascular diseases, diabetes, lung diseases and complications of pregnancy. The purpose of this editorial is to provide a current and thoughtful perspective on the relationship of diet and natural agents on oral, periodontal diseases, and chewing disorder preventions which may reflect good systemic conditions and related quality of life or to analyze indirect effects through the contribution of diet and nutrition to systemic health in order to obtain a modern diagnostic-therapeutic approach.

Maternally-Expressed Gene 3 (MEG3)/miR-143-3p Regulates Injury to Periodontal Ligament Cells by Mediating the AKT/Inhibitory κB Kinase (IKK) Pathway

Background

Dysregulated long noncoding RNAs (lncRNAs) are implicated in periodontitis development. Nevertheless, the role and mechanism of lncRNA maternally-expressed gene 3 (MEG3) in periodontitis progression remain unclear. This study aimed to explore how and whether MEG3 affect viability, apoptosis, and inflammatory response in lipopolysaccharide (LPS)-treated periodontal ligament cells (PDLCs).

Material/Methods

Periodontal ligament tissues were collected from periodontitis patients or normal individuals. PDLCs were obtained from normal periodontal ligament and treated with lipopolysaccharide (LPS). LPS-induced PDLCs injury was assessed via viability, apoptosis and inflammatory response using Cell Counting Kit-8, flow cytometry, quantitative reverse transcription polymerase chain reaction, enzyme-linked immunosorbent assay, and Western blot. The levels of MEG3 and microRNA (miR)-143-3p were examined via quantitative reverse transcription polymerase chain reaction. The protein kinase B(AKT)/inhibitory κB kinase (IKK) pathway was analyzed via Western blot. The target correlation of MEG3 and miR-143-3p was determined through dual-luciferase reporter analysis.

Results

MEG3 level was decreased and miR-143-3p level was upregulated in periodontitis and LPS-treated PDLCs. MEG3 overexpression or miR-143-3p knockdown alleviated LPS-induced viability inhibition, apoptosis promotion, and inflammatory response. MEG3 was a sponge for miR-143-3p. miR-143-3p overexpression weakened the effect of MEG3 on LPS-induced injury. MEG3 overexpression inhibited the activation of AKT/IKK pathway by sponging miR-143-3p in LPS-treated PDLCs.

Conclusions

MEG3 overexpression inhibited LPS-induced injury in PDLCs by inactivating the AKT/IKK pathway via sponging miR-143-3p, providing a potential target for treatment of periodontitis.

Expression of MicroRNAs in Periodontal and Peri-Implant Diseases: A Systematic Review and Meta-Analysis

AIM

The purpose of this review was to evaluate the expression patterns of miRNAs in periodontal and peri-implant diseases, while identifying potential miRNAs with the greatest diagnostic ability as an oral fluid biomarker.

MATERIALS AND METHODS

Human and animal studies were included when evaluating expression of miRNAs between health and different forms/stages of diseases, in which microarray and/or real-time polymerase chain reaction (RT-PCR) was carried out to detect fold changes in gene expression. After full-text analysis, 43 articles were considered for a qualitative assessment, and 16 miRNAs were selected to perform meta-analysis.

RESULTS

Based on human studies, results showed an overall upregulation of most of the evaluated miRNAs in periodontitis, with miRNA-142-3p and miRNA-146a being the most conclusive on both microarray and RT-PCR values and potentially serving as diagnostic biomarkers for disease activity. Conversely, miR-155 was the only miRNA revealing a statistically significant difference (SSD) (p < 0.05*) in experimental periodontitis models from RT-PCR values. Scarce scientific evidence is available from peri-implant diseases, however, most explored miRNAs in peri-implantitis were downregulated except for miR-145.

CONCLUSIONS

Although our results revealed that a distinct differential expression of specific miRNAs can be noted between the state of health and disease, future research remains necessary to explore the functional role of specific miRNAs and their potential as therapeutic targets in periodontal and peri-implant diseases. MeSH Terms: periodontitis, peri-implantitis, epigenomics, microarray analysis, real-time polymerase chain reaction, microRNAs.

CLINICAL RELEVANCE

Scientific background: Although most research identified different expression levels of miRNAs in periodontal and peri-implant diseases compared to their counterparts, their actual role in the pathogenesis of these conditions remains unclear. Therefore, we aimed to present a systematic review and meta-analysis on the expression patterns of miRNAs in periodontitis and peri-implantitis, while identifying potential miRNAs with the greatest diagnostic ability as an oral fluid biomarker.

PRINCIPAL FINDINGS

In periodontitis-related studies, miRNA-142-3p and miRNA-146a were the most conclusive on both microarray and RT-PCR values. Scarce scientific evidence is available from peri-implant diseases.

PRACTICAL IMPLICATIONS

Both miRNA-142-3p and miRNA-146a might serve as future diagnostic biomarkers for disease activity in periodontitis. Yet, future research remains necessary to explore the functional role of specific miRNAs and their potential as therapeutic targets in periodontal and peri-implant diseases.

Periodontitis and oral cancer - current concepts of the etiopathogenesis

Gingival tissues are attacked by oral pathogens which can induce inflammatory reactions. The immune-inflammatory responses play essential roles in the patient susceptibility to periodontal diseases. There is a wealth of evidence indicating a link between chronic inflammation and risk of malignant transformation of the affected oral epithelium. Periodontitis is associated with an increased risk of developing chronic systemic conditions including autoimmune diseases and different types of cancers. Besides, some risk factors such as smoking, alcohol consumption and human papilloma virus have been found to be associated with both periodontitis and oral cancer. This review article aimed to study the current concepts in pathogenesis of chronic periodontitis and oral cancer by reviewing the related articles.