MicroRNA sequence analysis identifies microRNAs associated with peri-implantitis in dogs

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.

Experimental models for peri-implant diseases: a narrative review

OBJECTIVES

Peri-implant diseases, being the most common implant-related complications, significantly impact the normal functioning and longevity of implants. Experimental models play a crucial role in discovering potential therapeutic approaches and elucidating the mechanisms of disease progression in peri-implant diseases. This narrative review comprehensively examines animal models and common modeling methods employed in peri-implant disease research and innovatively summarizes the in vitro models of peri-implant diseases.

MATERIALS AND METHODS

Articles published between 2015 and 2023 were retrieved from PubMed/Medline, Web of Science, and Embase. All studies focusing on experimental models of peri-implant diseases were included and carefully evaluated.

RESULTS

Various experimental models of peri-implantitis have different applications and advantages. The dog model is currently the most widely utilized animal model in peri-implant disease research, while rodent models have unique advantages in gene knockout and systemic disease induction. In vitro models of peri-implant diseases are also continuously evolving to meet different experimental purposes.

CONCLUSIONS

The utilization of experimental models helps simplify experiments, save time and resources, and promote advances in peri-implant disease research. Animal models have been proven valuable in the early stages of drug development, while technological advancements have brought about more predictive and relevant in vitro models.

CLINICAL RELEVANCE

This review provides clear and comprehensive model selection strategies for researchers in the field of peri-implant diseases, thereby enhancing understanding of disease pathogenesis and providing possibilities for developing new treatment strategies.

Reprogramming mitochondrial metabolism of macrophages by miRNA-released microporous coatings to prevent peri-implantitis

Although various new biomaterials have enriched the methods for peri-implant inflammation treatment, their efficacy is still debated, and secondary operations on the implant area have also caused pain for patients. Recently, strategies that regulate macrophage polarization to prevent or even treat peri-implantitis have attracted increasing attention. Here, we prepared a laser-drilled and covered with metal organic framework-miR-27a agomir nanomembrane (L-MOF-agomir) implant, which could load and sustain the release of miR-27a agomir. In vitro, the L-MOF-agomir titanium plate promoted the repolarization of LPS-stimulated macrophages from M1 to M2, and the macrophage culture supernatant promoted BMSCs osteogenesis. In a ligation-induced rat peri-implantitis model, the L-MOF-agomir implants featured strong immunomodulatory activity of macrophage polarization and alleviated ligation-induced bone resorption. The mechanism of repolarization function may be that the L-MOF-agomir implants promote the macrophage mitochondrial function and metabolism reprogramming from glycolysis to oxidative phosphorylation. Our study demonstrates the feasibility of targeting cell metabolism to regulate macrophage immunity for peri-implantitis inhibition and provides a new perspective for the development of novel multifunctional implants.

Dental implant material related changes in molecular signatures in peri-implantitis - A systematic review of omics in-vivo studies

OBJECTIVE

Titanium particles have been shown in in-vitro studies to lead to the activation of specific pathways, this work aims to systematically review in- vivo studies examining peri-implant and periodontal tissues at the transcriptome, proteome, epigenome and genome level to reveal implant material-related processes favoring peri-implantitis development investigated in animal and human trials.

METHODS

Inquiring three literature databases (Medline, Embase, Cochrane) a systematic search based on a priori defined PICOs was conducted: '-omics' studies comparing molecular signatures in healthy and infected peri-implant sites and/or healthy and periodontitis-affected teeth in animals/humans. After risk of bias assessments, lists of differentially expressed genes and results of functional enrichment analyses were compiled whenever possible.

RESULTS

Out of 2187 screened articles 9 publications were deemed eligible. Both healthy and inflamed peri-implant tissues showed distinct gene expression patterns compared to healthy/diseased periodontal tissues in animal (n = 4) or human studies (n = 5), with immune response, bone metabolism and oxidative stress being affected the most. Due to the lack of available re-analyzable data and inconsistency in methodology of the eligible studies, integrative analyses on differential gene expression were not applicable CONCLUSION: The differences of transcriptomic signatures in between peri-implant lesions compared to periodontal tissue might be related to titanium particles arising from dental implants and are in line with the in-vitro data recently published by our group. Nevertheless, limitations emerge from small sample sizes of included studies and insufficient publication of re-analyzable data.

A review on microRNA detection and expression studies in dogs

MicroRNAs (miRNAs) are small non-coding RNAs that function by post-transcriptional regulation of gene expression. Their stability and abundance in tissue and body fluids makes them promising potential tools for both the diagnosis and prognosis of diseases and attractive therapeutic targets in humans and dogs. Studies of miRNA expression in normal and disease processes in dogs are scarce compared to studies published on miRNA expression in human disease. In this literature review, we identified 461 peer-reviewed papers from database searches using the terms "canine," "dog," "miRNA," and "microRNA"; we screened 244 for inclusion criteria and then included a total of 148 original research peer-reviewed publications relating to specific miRNA expression in canine samples. We found an overlap of miRNA expression changes between the four groups evaluated (normal processes, non-infectious and non-inflammatory conditions, infectious and/or inflammatory conditions, and neoplasia) in 39 miRNAs, 83 miRNAs in three of the four groups, 110 miRNAs in two of the three groups, where 158 miRNAs have only been reported in one of the groups. Additionally, the mechanism of action of these overlapping miRNAs varies depending on the disease process, elucidating a need for characterization of the mechanism of action of each miRNA in each disease process being evaluated. Herein we also draw attention to the lack of standardization of miRNA evaluation, consistency within a single evaluation method, and the need for standardized methods for a direct comparison.

miR-27a-5p alleviates periodontal inflammation by targeting phosphatase and tensin homolog deleted on chromosome ten

INTRODUCTION

MicroRNAs (miRNAs), a type of non-coding RNA, have been demonstrated to be essential posttranscriptional modulators in oral diseases and inflammatory responses. However, the specific role of miR-27a-5p in periodontitis requires further investigation. In this study, we used both cellular and animal models to determine how miR-27a-5p affects the pathogenesis of periodontitis and its associated biological functions.

METHODS

Quantitative real-time polymerase chain reaction and western blotting were used to analyze the expression of cytokines, phosphatase and tensin homolog deleted on chromosome ten (PTEN), and miR-27a-5p transcription. Investigation of alveolar bone resorption and inflammation of the periodontium in ligature-induced periodontitis in mice was performed using micro-computed tomography (micro-CT), hematoxylin-eosin (HE) staining, and tartrate-resistant acid phosphatase (TRAP) staining. The binding of miR-27a-5p and PTEN was predicted using the TargetScan database and experimentally confirmed using dual luciferase reporter gene assays.

RESULTS

The inflamed gingiva showed lower levels of miR-27a-5p. Macrophages from miR-27a-5p^-/- mice produced much higher quantities of pro-inflammatory cytokines owing to the stimulation of Porphyromonas gingivalis lipopolysaccharide, and miR-27a-5p^-/- mice with ligature-induced periodontitis also exhibited more severe alveolar bone resorption and damage to the periodontium. Target validation assays identified PTEN as a direct target of bona. Blocking PTEN expression partially reduced inflammation, both in vitro and in vivo.

CONCLUSIONS

miR-27a-5p alleviated the inflammatory response in periodontitis by targeting PTEN.

MicroRNA and Messenger RNA Expression Profiles in Canine Mammary Gland Tumor

Canine mammary gland tumor (CMT) is the most frequently diagnosed neoplasm in intact female dogs. As prognosis depends on the malignancy of tumors and metastasis levels, early and accurate diagnosis are crucial for prolongation of life expectancy. The genetic similarity of dogs with humans in addition to environmental and physiological similarities make them ideal models for the study of cancer. In this study, we analyzed differentially expressed microRNAs followed by RNA-Seq to investigate the alterations in mRNA levels based on the malignancy (benign, malignant) and the biopsy locations (tumors, surrounding normal tissues). We identified multiple breast cancer-related genes regardless of malignancy. We found cfa-miR-503 to be the only miRNA that showed altered expression in response to malignancy in CMTs. Although further validation is needed, cfa-miR-503 could be used as a potential diagnostic biomarker as well as a potential RNA-based anti-tumor drug in malignant CMTs.

MicroRNA sequence and function analysis in peri-implantitis and periodontitis: An animal study

OBJECTIVE

To compare miRNA expression levels and predict relevant target genes and signaling pathways in peri-implantitis and periodontitis.

BACKGROUND

There are many differences between periodontitis and peri-implantitis. An understanding of the similarities and differences in the transcriptional patterns of these diseases, as well as the molecular mechanisms, is beneficial for the development of management strategies.

MATERIALS AND METHODS

Rat models of periodontitis (PD, n = 6) and peri-implantitis (PI, n = 5) were established by ligation. Implantation without ligation (PIC, n = 5) and normal rats (PDC, n = 6) were used as controls. Micro-CT was used to confirm the successful establishment of the model. Gingiva was harvested for miRNA transcriptome sequencing, and the results were confirmed by qRT-PCR. miRNA target genes were predicted with miRTarBase. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed.

RESULTS

Sixty-nine miRNAs were differentially expressed in PI vs. PD, 105 were differentially expressed in PI vs. PIC, and 70 were differentially expressed in PD vs. PDC (log₂ FC ≥1 and padj <0.05). The upregulated genes in all three comparisons were mostly involved in the biological process response to stimulus, whereas most of the downregulated genes were involved in nervous system development (p < .01). The upregulated genes in PI vs. PD and PI vs. PIC were involved in Toll-like receptor signaling and RIG-I-like signaling. The upregulated genes in PI vs. PD were involved in T- and B-cell receptor signaling, apoptosis, and osteoclast differentiation. Focal adhesion was downregulated in all three comparisons, and adherens junction was downregulated in PI vs. PD and PD vs. PDC (p < .1).

CONCLUSION

This study showed differences in the miRNA expression profiles between peri-implantitis and periodontitis and annotated the possible target genes and molecular mechanisms; this study could lay a foundation for the development of management strategies.

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.

Gingival crevicular fluid microRNA associations with periodontitis

PURPOSE

The present study was performed to assess the associations of gingival crevicular fluid (GCF) microRNAs miR-140-3p, miR-145-5p, miR-146a-5p, and miR-195-5p with periodontitis (PD) and to evaluate the possible influence of rheumatoid arthritis (RA) in this context.

METHOD

GCF samples were collected from 134 individuals with PD and 76 periodontally healthy individuals, with or without RA. After miRNA extraction from GCF, the levels of miR-140-3p, miR-145-5p, miR-146a-5p, and miR-195-5p were assessed using RT-qPCR.

RESULTS

MiR-146a-5p levels were significantly lower among the patients with PD than among the healthy individuals (P < 0.001) and negatively correlated with PD severity based on PD stage and periodontal outcome parameters (P < 0.05). Patients with severe PD had higher GCF levels of miR-140-3p and miR-145-5p than did periodontally healthy individuals (P < 0.05). Significant AUC values for diagnosis of severe PD were revealed for miR-140-3p (AUC = 0.614, P = 0.022), miR-145-5p (AUC = 0.621, P = 0.016) and miR-146a-5p (AUC = 0.702, P < 0.001). Combination of the aforementioned miRNAs increased the diagnostic performance (AUC = 0.709, P < 0.001).

CONCLUSION

It was demonstrated that miR-140-3p, miR-145-5p and miR-146a-5p were associated with PD and would be potentially effective for GCF-based non-invasive periodontitis diagnostics in patients with and without RA.

Metabolites of the Oral Microbiome: Important Mediators of Multi-Kingdom Interactions

The oral cavity hosts over 700 different microbial species that produce a rich reservoir of bioactive metabolites critical to oral health maintenance. Over the last two decades, new insights into the oral microbiome and its importance in health and disease have emerged mainly due to the discovery of new oral microbial species using next-generation sequencing (NGS). This advancement has revolutionized the documentation of unique microbial profiles associated with different niches and health/disease states within the oral cavity and the relation of the oral bacteria to systemic diseases. However, less work has been done to identify and characterize the unique oral microbial metabolites that play critical roles in maintaining equilibrium between the various oral microbial species and their human hosts. This article discusses the most significant microbial metabolites produced by these diverse communities of oral bacteria that can either foster health or contribute to disease. Finally, we shed light on how advances in genomics and genome mining can provide a high throughput platform for discovering novel bioactive metabolites derived from the human oral microbiome to tackle emerging human infections and systemic diseases.

Role of enhancer of zeste homolog 2 in osteoclast formation and periodontitis development by downregulating microRNA-101-regulated VCAM-1

The enhancer of zeste homolog 2 (EZH2) represents a potential target for periodontitis treatment; however, its role in the development of periodontitis remains unclear. The current study aimed to elucidate the role of EZH2 in osteoclasts (OCs) growth as well as the mechanism underpinning the related process. The potential interaction among EZH2, microRNA-101 (miR-101), and vascular cell adhesion molecule 1 (VCAM-1) was evaluated using chromatin immunoprecipitation and dual-luciferase reporter gene assay. The expressions of EZH2 and miR-101 in OCs were examined by Western blot analysis and reverse transcription squantitative polymerase chain reaction. Loss- and gain-function assays were then performed to determine the role of EZH2/miR-101/VCAM-1 in periodontitis and OCs proliferation, followed by OC growth and proliferation detected using tartrate resistant acid phosphatase (TRAP) and 5-ethynyl-2'-deoxyuridine staining. Enzyme-linked immunoassay was conducted to determine the expression of interleukin 1β (IL-1β) and tumor necrosis factor-α (TNF-α). A periodontitis rat model was established to investigate the effect of EZH2 and VCAM-1 in vivo. EZH2 was overexpressed, while miR-101 was downregulated in the OCs of periodontitis. Silencing of EZH2, VCAM-1 repression, or miR-101 elevation suppressed the growth and proliferation of OC while acting to encumber the release of IL-1β and TNF-α. EZH2 negatively targeted miR-101, while miR-101 negatively targeted VCAM-1. Moreover, silencing of EZH2 or VCAM-1 was observed to attenuate periodontitis which was evidenced by an increase in BMD, BV/TV, and BS/BV as well as reduction in TRAP and cathepsin K in vivo. Taken together, the key findings of the current study demonstrate that EZH2 knockdown inhibited OC formation by elevating the expression of miR-101 via suppression of VCAM-1, ultimately attenuating periodontitis.

MicroRNA in Implant Dentistry: From Basic Science to Clinical Application

Specific microRNA (miRNA) expression profiles have been reported to be predictive of specific clinical outcomes of dental implants and might be used as biomarkers in implant dentistry with diagnostic and prognostic purposes. The aim of the present narrative review was to summarize current knowledge regarding the use of miRNAs in implant dentistry. The authors attempted to identify all available evidence on the topic and critically appraise it in order to lay the foundation for the development of further research oriented towards the clinical application of miRNAs in implant dentistry.

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.

Peri-Implant Diseases: Diagnosis, Clinical, Histological, Microbiological Characteristics and Treatment Strategies. A Narrative Review

Since the use of dental implants is continuously increasing, it is imperative for dental practitioners to understand the nature and treatment of peri-implant diseases. The purpose of this manuscript is to comprehensively review peri-implant diseases, their characteristics, as well as their non-surgical and surgical treatment. To that end, the current literature was searched and a narrative review was conducted. It is essential that the case definitions described in the 2017 World Workshop on the Classification of Periodontal and Peri-implant Diseases and Conditions are used to diagnose and classify peri-implant health, peri-implant mucositis and peri-implantitis. While recent epidemiologic studies on peri-implant diseases exist, there is great heterogeneity in the definition of these conditions. Several risk factors and indicators are reported in the literature, with smoking and diabetes being the most universally accepted. In peri-implant mucositis, non-surgical treatment seems to be sufficient. However, for the treatment of peri-implantitis, a surgical approach, which includes open-flap debridement, apically positioned flap and guided bone regeneration, is considered more appropriate. A great variety of adjuncts to mechanical treatment have been reported with controversial results. Finally, studies comparing results from different peri-implantitis treatments are warranted in randomized controlled clinical trials in order to provide stronger evidence-based approaches.

Diagnostic potential of peri-implant crevicular fluid microRNA-21-3p and microRNA-150-5p and extracellular vesicles in peri-implant diseases

BACKGROUND

To explore the diagnostic usefulness of extracellular vesicles (EVs), and their subpopulations (micro-vesicles and exosomes), and microRNAs (miRNA-21-3p, miRNA-150-5p, and miRNA-26a-5p) in peri-implant crevicular fluid (PICF) of subjects with healthy, peri-implant mucositis and peri-implantitis implants.

METHODS

A total of 54 patients were enrolled into healthy, peri-implant mucositis, and peri-implantitis groups. PICF samples were collected, EVs subpopulations (MVs and Exo) were isolated and characterized by nanoparticle tracking analysis and transmission electron microscopy. The expression of miRNA-21-3p, miRNA-150-5p and miRNA-26a-5p was quantified by qRT-PCR. Logistic regression models and accuracy performance tests were estimated.

RESULTS

PICF samples show the presence of EVs delimited by a bi-layered membrane, in accordance with the morphology and size (< 200 nm). The concentration of PICF-EVs, micro-vesicles and exosomes was significantly increased in peri-implantitis implants compared to healthy implants (P = 0.023, P = 0.002, P = 0.036, respectively). miRNA-21-3p and miRNA-150-5p expression were significantly downregulated in patients with peri-implantitis in comparison with peri-implant mucositis sites (P = 0.011, P = 0.020, respectively). The reduced expression of miRNA-21-3p and miRNA-150-5p was associated with peri-implantitis diagnosis (OR:0.23, CI 0.08-0.66, P = 0.007 and OR:0.07, CI 0.01-0.78, P = 0.031, respectively). The model which included the miRNA-21-3p and miRNA-150-5p expression had a sensitivity of 93.3%, a specificity of 76.5%, a positive predictive value of 77.8%, and a negative predictive value of 92.9%. The positive and negative likelihood ratios were 3.97 and 0.09, respectively. The area under the receiver operating characteristics curve for the model was 0.84.

CONCLUSIONS

An increase concentration of EVs with a downregulation expression of miRNA-21-3p and miRNA-150-5p could be related with the peri-implantitis development.

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.

LncRNA-mediated ceRNA network was identified as a crucial determinant of differential effects in periodontitis and periimplantitis by high-throughput sequencing

BACKGROUND AND OBJECTIVE

Although periimplantitis and periodontitis share similar features, particularly clinical features, they are two different diseases and should be analyzed separately. Thus far, few omics-level differences in periimplantitis and periodontitis have been reported. This study was aimed at exploring the differential effects of expression mRNAs, lncRNAs, and miRNAs in periodontitis and periimplantitis by high-throughput sequencing and competitive endogenous RNA (ceRNA) analysis.

METHODS

Gingival tissues of healthy individuals (HI) and periimplantitis (PI) and periodontitis (P) patients were collected and used for genome-wide sequencing. The differentially expressed genes (DEGs) were screened and visualized by R software. The functions and pathways of DEGs were analyzed using Metascape, and the ceRNA network was constructed using the Cytoscape software. Finally, gene set enrichment analysis (GSEA) was used to predict the function of key nodes in ceRNA.

RESULTS AND CONCLUSION

By constructing the regulated ceRNA network, six genes (FAM126B, SORL1, PRLR, CPEB2, RAP2C, and YOD1) and 16 miRNAs (hsa-miR-338-5p, hsa-miR-650, hsa-miR-9-5p, hsa-miR-1290, hsa-miR-544a, hsa-miR-3179, hsa-miR-1269a, hsa-miR-3679-5p, hsa-miR-149-5p, hsa-miR-615-3p, hsa-miR-33b-5p, hsa-miR-31-5p, hsa-miR-4639-5p, hsa-miR-204-5p, hsa-miR-5588-5p, and hsa-mir-196a-5p) were detected. Five long non-coding RNAs (lnc-CORO2B-1, lnc-MBL2-7, lnc-TRIM45-1, lnc-CHST10-2, and lnc-TNP1-6) were found to target these miRNAs in this ceRNA network. The ceRNA network based on transcriptome data revealed that FAM126B, SORL1, PRLR, CPEB2, RAP2C, and YOD1 were crucial proteins of differential effects in periodontitis and periimplantitis. The lncRNA-miRNA-mRNA interaction involved the regulation of the Hippo signaling pathway, Wnt signaling pathway, Toll-like receptor signaling pathway, NOD signaling pathway, oxidative stress, and innate immune process. These regulated pathways and biological processes may be factors contributing to the pathogenesis of periimplantitis being distinct from that of periodontitis.

MiR-128 promotes osteogenic differentiation of bone marrow mesenchymal stem cells in rat by targeting DKK2

Bone loss caused by inflammatory disease, such as peri-implantitis, poses a great challenge to clinicians for restoration. Emerging evidence indicates that microRNAs (miRNAs) are indispensable regulators of bone growth, development, and formation. In the present study, we found that microRNA-128 (miR-128) was differentially up-regulated during the osteogenic differentiation of rat bone marrow stem cells (rBMSCs). Overexpression of miR-128 promoted osteogenic differentiation of rBMSCs by up-regulating alkaline phosphatase (ALP), matrix mineralization, mRNA, and protein levels of osteogenic makers (e.g. RUNX2, BMP-2, and COLIA1), whereas inhibition of miR-128 suppressed osteoblastic differentiation in vitro. Mechanistically, miR-128 directly and functionally targeted Dickkopf2 (DKK2), which is a Wnt signaling pathway antagonist, and enhanced Wnt/β-catenin signaling activity. Furthermore, the positive effect of miR-128 on osteogenic differentiation was apparently abrogated by DKK2 overexpression. Collectively, these results indicate that miR-128 promotes osteogenic differentiation of rBMSCs by targeting DKK2, which may provide a promising approach to the treatment of peri-implantitis.

Comparison of the structure and function of a chimeric peptide modified titanium surface

Peri-implantitis is a plaque-initiating infectious disease that can be prevented by interfering with the initial bacterial attachment. At present, surface modification of implants using antimicrobial peptides can interfere with the adhesion of streptococci. In this study, the structure and function of chimeric peptides were compared to get a strategy to modify a Ti surface. Compared to the antimicrobial activity with a fragment of hBD-3, the bifunctional and multifunctional chimeric peptides retain their antimicrobial function. All peptides showed antimicrobial activity against streptococcus in biofilm and planktonic conditions. The results demonstrate significant improvement in reducing bacterial colonization onto titanium surfaces. According to the results of structure analysis, the antimicrobial activity of tyrosine in hBD3-3 was stronger than that of the alpha helix in bifunctional or multifunctional chimeric peptides. Rigid connections were proved to avoid functional domain changes due to the interaction of charges. These results indicated that the endogenous peptide fragments modifying the Ti surface could provide an environmentally friendly approach to reduce or prevent the occurrence of peri-implant diseases.

The antimicrobial activity of Tyr structure in hBD3-3 is stronger than that of the α-helix structure in multifunctional chimeric peptides. Rigid connections avoid functional domain changes. Endogenous peptide fragments on a Ti surface could reduce peri-implant diseases.

MiR-27a targets DKK2 and SFRP1 to promote reosseointegration in the regenerative treatment of peri-implantitis

In the inflamed microenvironment of peri-implantitis, limited osteogenesis on the implant surface impedes well-established reosseointegration using current clinical therapies. MicroRNAs (miRNAs) function as potent molecular managers that may simultaneously regulate multiple endogenous processes such as inflammation and osteogenesis. The delivery of miRNAs may provide a way to effectively treat some diseases. In this study, we showed that miR-27a was differentially downregulated in samples from a canine peri-implantitis model. We found that overexpressing miR-27a positively regulated osteogenesis-angiogenesis coupling by ameliorating the TNF-α inhibition of bone formation in vitro. Mechanistically, we identified Dickkopf2 (DKK2) and secreted frizzled related protein 1 (SFRP1) as two essential direct miR-27a targets that were osteogenic and angiogenic. Furthermore, we constructed a miR-27a-enhanced delivery system to repair the bone defect around implants in a canine peri-implantitis model. The results demonstrated that the miR-27a-treated group could optimize new bone formation and reosseointegration in vivo. Our assay provides evidence that this strategy exerts therapeutic effects on peri-implantitis, suggesting that it represents a feasible method to maintain the stability and masticatory function of dental implants. © 2018 American Society for Bone and Mineral Research.

miR-145 eliminates lipopolysaccharides-induced inflammatory injury in human fibroblast-like synoviocyte MH7A cells

Recently, it has been accepted that miR-based therapy may be beneficial for rheumatoid arthritis (RA). This study aimed to evaluate the potential involvement of miR-145 in RA in vitro. The expression of miR-145 in the human fibroblast-like synoviocyte line MH7A was overexpressed by miR-mimic transfection, after which cells were subjected to lipopolysaccharides (LPS). Cell viability, apoptosis, and the release of pro-inflammatory cytokines were measured. The result showed that the apoptosis and the release of IL-1β, IL-6, IL-8, and TNF-α were significantly induced by LPS. Meanwhile, LPS treatment led to downregulation of miR-145. miR-145 overexpression in LPS-untreated MH7A cells had no impacts on cell apoptosis and inflammation. But, restoring miR-145 expression in LPS-stimulated cells by supplementation of a miR-145 mimic protected MH7A cells against LPS-induced apoptosis and inflammation. Furthermore, miR-145 overexpression in LPS-untreated MH7A cells slightly blocked the PI3K/ATK and mTOR pathways, whereas miR-145 overexpression in LPS-stimulated cells notably repressed the LPS-induced activation of PI3K/ATK and MAPK/mTOR pathways. Our study suggested that miR-145 protected MH7A cells against LPS-induced apoptosis and inflammation by inhibiting the PI3K/AKT and MAPK/mTOR pathways.