MiR-200b attenuates IL-6 production through IKKβ and ZEB1 in human gingival fibroblasts

METTL3 Promotes Osteogenic Differentiation of Human Periodontal Ligament Stem Cells Under the Inflammatory Microenvironment Through the miR-141-3p/ZEB1 Axis

Periodontitis, a chronic inflammatory condition, often results in gum tissue damage and can lead to tooth loss. This study explores the role of methyltransferase-like 3 (METTL3) in promoting osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs) within an inflammatory microenvironment. An inflammatory environment was simulated in hPDLSCs using lipopolysaccharide (LPS). Both adipogenic and osteogenic differentiation capacities of hPDLSCs were assessed. In LPS-treated hPDLSCs, METTL3 was overexpressed, and alkaline phosphatase (ALP) staining was performed alongside measurements of ALP activity, pro-inflammatory cytokines, METTL3, miR-141-3p, pri-miR-141, Zinc finger E-box binding homeobox 1 (ZEB1), runt-related transcription factor 2 (RUNX2), osteocalcin (OCN). N6-methyladenosine (m6A) and pri-miR-141 levels were quantified, and the binding of miR-141-3p to ZEB1 was analyzed. The results demonstrated that osteogenic differentiation in hPDLSCs was diminished under inflammatory conditions, coinciding with downregulated METTL3 expression. However, METTL3 overexpression enhanced osteogenic differentiation. METTL3 facilitated the conversion of pri-miR-141 into miR-141-3p via m6A modification, resulting in increased miR-141-3p levels, which in turn suppressed ZEB1 expression. Inhibition of miR-141-3p or overexpression of ZEB1 partially counteracted the positive effects of METTL3 on osteogenic differentiation. In conclusion, these findings suggest that METTL3-mediated m6A modification promotes osteogenic differentiation of hPDLSCs within an inflammatory microenvironment through the miR-141-3p/ZEB1 axis.

miR-128-3p Reduces Proliferation and Immune Escape in Acute Myeloid Leukemia Through Targeted Regulation of ZEB1

microRNAs have received wide attention as potential therapeutic targets. This study explored the action of miR-128-3p in acute myeloid leukemia (AML). miR-128-3p expression in AML was determined by quantitative PCR method. MTT proliferation assay and immunoblot assay were employed to detect proteins related to proliferation and apoptosis in THP-1 cells overexpressing miR-128-3p. RNA immunoprecipitation and dual luciferase reporting system were utilized to verify downstream targets of miR-128-3p. Flow cytometry was conducted to analyze the apoptosis rate and immune escape of THP-1 cells in the T-cell co-culture system. miR-128-3p was lowly expressed in AML patients (reduced by 41.6%). Overexpression of miR-128-3p inhibited THP-1 cell proliferation and immune escape, and stimulated apoptosis. ZEB1 was a downstream target of miR-128-3p, and up-regulation of miR-128-3p inhibited ZEB1 mRNA and protein expression (respectively reduced by 65.8% and 42.0%). Upregulating ZEB1 reversed the inhibitory effect of upregulating miR-128-3p on THP-1 cell proliferation and immune escape. Upregulating ZEB1 promoted PD-L1 protein expression (increased by 0.75-fold). Blocking PD-L1 reversed the promotion of THP-1 cell proliferation and immune escape by upregulating ZEB1. The miR-128-3p/ZEB1/PD-L1 axis is involved in regulating the proliferation and immune escape of AML cells, providing new insights into the molecular mechanism of miR-128-3p in AML and, more importantly, a new target for immunotherapy of AML.

Sodium Danshensu Inhibits Macrophage Inflammation in Atherosclerosis via the miR-200a-3p/MEKK3/NF-κB Signaling Pathway

Macrophages are fundamental cellular components of atherosclerotic plaques, and inhibition of macrophage inflammation can delay the development of atherosclerotic plaques. Sodium danshensu (SDSS) can inhibit inflammatory responses and thus delay atherosclerosis, but the specific mechanism remains unclear. The effect of SDSS in inhibiting atherosclerosis was confirmed by observing and detecting atherosclerotic plaque area, morphology and lipid levels in the aorta. The mechanism by which SDSS attenuated atherosclerotic plaques was elucidated by in vivo and in vitro detection of inflammation-related mRNA and protein expression. In addition, bioinformatics analysis, RT-qPCR and dual-luciferase assays were used to predict and validate the potential miRNAs of SDSS to attenuate atherosclerosis. miR-200a-2p mimic and inhibitor were then compared for their effects on the efficacy of SDSS. SDSS inhibited atherosclerotic plaque formation and suppressed the expression of MEKK3, TNF-α, and IL-1β as well as nuclear factor-κB (NF-κB) phosphorylation and nuclear translocation to attenuate inflammatory responses. Bioinformatic predictions combined with RT-qPCR results and dual-luciferase assays indicated that miR-200a-3p negatively regulated MEKK3 expression by directly targeting the 3'UTR region of MEKK3, thereby blocking MEKK3. Further studies showed that miR-200a-3p inhibitor, but not miR-200a-3p mimic, reversed the beneficial effects of SDSS on inflammation. SDSS inhibited macrophage inflammation by modulating the miR-200a-3p/MEKK3/NF-κB signaling pathway.

Mitochondrial dysfunction as a key player in aggravating periodontitis among diabetic patients: review of the current scope of knowledge

Periodontitis is a prevalent inflammatory disease that leads to significant periodontal tissue destruction and compromised dental health, with its severity exacerbated in individuals with Diabetes Mellitus (DM). This review explores the complex relationship between mitochondrial dysfunction and periodontitis in diabetic patients. Recent studies indicate that the excessive production of reactive oxygen species (ROS), primarily generated by dysfunctional mitochondrial electron transport chain (ETC) complexes, contributes to oxidative stress (OS) and subsequent periodontal tissue damage. The interplay between impaired mitochondrial biogenesis, apoptosis of periodontal cells, and ROS accumulation highlights a critical area of concern in understanding the pathophysiology of diabetic periodontitis. Furthermore, altered glycemic control due to inflammatory processes associated with periodontitis may perpetuate a cyclical detriment to oral and systemic health. This review aims to highlight the mechanistic roles of mitochondrial dysfunction in the aggravation of periodontitis among diabetic patients, emphasizing further research to identify potential therapeutic targets and improve treatment efficacy for this dual pathology.

Mimicking and in vitro validating chronic inflammation in human gingival fibroblasts

OBJECTIVE

The aim of this study was to identify and validate in vitro conditions that may mimic the translational, cytokine and chemokine profiles observed in human inflamed gingiva in vivo.

DESIGN

Primary human gingiva fibroblast cells (HFIB-G) were cultured under serum starvation conditions (0 - 10 %), supplemented with increasing lipopolysaccharide (LPS) concentrations (0.1, 1, or 10 µg/ml) from two bacterial strains E. coli and P. gingivalis and 0.1, 1, or 10 ng/ml recombinant interleukin 1β (IL-1β), alone or in combinations. The levels of cytokines/chemokines were measured in the cell culture medium by Luminex, and gene expression was quantified by Affymetrix microarrays at 24, 48 and 72 h.

RESULTS

Inflammation markers were not elevated after stimulation with P. gingivalis LPS, while E. coli LPS and IL-1β individually increased the secretion of interleukin 6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1) to the cell culture medium. IL-1β administration also increased the secretion of several factors, including tumor necrosis factor (TNFα). However, the combination of 1 µg/ml E. coli LPS, 1 ng/ml IL-1β and serum starvation led to increased secretion of IL-6, TNFα, in addition to other factors found in inflamed tissue. Gene expression analyses revealed that this combination not only enhanced the expression interleukins/chemokines genes but also T helper cell signaling and matrix metalloproteinases.

CONCLUSION

Serum reduction in cell culture medium together with the administration of E. coli LPS and IL-1β resulted in gene expression and secreted cytokine/chemokine profiles similar to that found in vivo during chronic inflammation.

Regulation of osteoclast differentiation and inflammatory signaling by TCF8 in periodontitis

OBJECTIVES

The aim of this study was to explore the potential role of zinc-finger homeodomain transcription factor (TCF8) in osteoclastogenesis and inflammation during periodontitis.

MATERIALS AND METHODS

Rats with periodontitis were induced via Porphyromonas gingivalis-lipopolysaccharide (Pg-LPS) injection. The recombinant lentivirus delivering short hairpin RNA (shRNA) against TCF8 was used to downregulate TCF8 in vivo. Alveolar bone loss in rats was determined by micro-computed tomography (Micro-CT). Typical pathological changes, periodontal tissue inflammation, and osteoclastogenesis were evaluated via histological analyses. The RAW264.7-derived osteoclasts were induced by RANKL stimulation. TCF8 downregulation in vitro was achieved by lentivirus infection. The osteoclast differentiation and inflammatory signaling in RANKL-induced cells were measured via immunofluorescence methods and molecular biology approaches.

RESULTS

Porphyromonas gingivalis-lipopolysaccharide induced rats exhibited overexpressed TCF8 in their periodontal tissues, while TCF8 knockdown attenuated the bone loss, tissue inflammation, and osteoclastogenesis in LPS-induced rats. Besides, TCF8 silencing inhibited RANKL-induced osteoclast differentiation in RAW264.7 cells, as evidenced by the reduced numbers of TRAP-positive osteoclasts, less formation of F-actin rings, and downregulated expressions of osteoclast-specific markers. It also exerted an inhibitory effect on the NF-κB signaling in RANKL-induced cells via blocking NF-κB p65 phosphorylation and nuclear translocation.

CONCLUSIONS

TCF8 silencing inhibited alveolar bone loss, osteoclast differentiation, and inflammation in periodontitis.

Restoration of epigenetic impairment in the skeletal muscle and chronic inflammation resolution as a therapeutic approach in sarcopenia

Sarcopenia is an age-associated loss of skeletal muscle mass, strength, and function, accompanied by severe adverse health outcomes, such as falls and fractures, functional decline, high health costs, and mortality. Hence, its prevention and treatment have become increasingly urgent. However, despite the wide prevalence and extensive research on sarcopenia, no FDA-approved disease-modifying drugs exist. This is probably due to a poor understanding of the mechanisms underlying its pathophysiology. Recent evidence demonstrate that sarcopenia development is characterized by two key elements: (i) epigenetic dysregulation of multiple molecular pathways associated with sarcopenia pathogenesis, such as protein remodeling, insulin resistance, mitochondria impairments, and (ii) the creation of a systemic, chronic, low-grade inflammation (SCLGI). In this review, we focus on the epigenetic regulators that have been implicated in skeletal muscle deterioration, their individual roles, and possible crosstalk. We also discuss epidrugs, which are the pharmaceuticals with the potential to restore the epigenetic mechanisms deregulated in sarcopenia. In addition, we discuss the mechanisms underlying failed SCLGI resolution in sarcopenia and the potential application of pro-resolving molecules, comprising specialized pro-resolving mediators (SPMs) and their stable mimetics and receptor agonists. These compounds, as well as epidrugs, reveal beneficial effects in preclinical studies related to sarcopenia. Based on these encouraging observations, we propose the combination of epidrugs with SCLI-resolving agents as a new therapeutic approach for sarcopenia that can effectively attenuate of its manifestations.

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.

Epigenome-wide association study using peripheral blood leukocytes identifies genomic regions associated with periodontal disease and edentulism in the Atherosclerosis Risk in Communities study

AIM

To investigate individual susceptibility to periodontitis by conducting an epigenome-wide association study using peripheral blood.

MATERIALS AND METHODS

We included 1077 African American and 457 European American participants of the Atherosclerosis Risk in Communities (ARIC) study who had completed a dental examination or reported being edentulous at Visit 4 and had available data on DNA methylation from Visit 2 or 3. DNA methylation levels were compared by periodontal disease severity and edentulism through discovery analyses and subsequent testing of individual CpGs.

RESULTS

Our discovery analysis replicated findings from a previous study reporting a region in gene ZFP57 (6p22.1) that was significantly hypomethylated in severe periodontal disease compared with no/mild periodontal disease in European American participants. Higher methylation levels in a separate region in an unknown gene (located in Chr10: 743,992-744,958) was associated with significantly higher odds of edentulism compared with no/mild periodontal disease in African American participants. In subsequent CpG testing, four CpGs in a region previously associated with periodontitis located within HOXA4 were significantly hypermethylated in severe periodontal disease compared with no/mild periodontal disease in African American participants (odds ratio per 1 SD increase in methylation level: cg11015251: 1.28 (1.02, 1.61); cg14359292: 1.24 (1.01, 1.54); cg07317062: 1.30 (1.05, 1.61); cg08657492: 1.25 (1.01, 1.55)).

CONCLUSIONS

Our study highlights epigenetic variations in ZPF57 and HOXA4 that are significantly and reproducibly associated with periodontitis. Future studies should evaluate gene regulatory mechanisms in the candidate regions of these loci.

Diabetes mellitus promotes susceptibility to periodontitis-novel insight into the molecular mechanisms

Diabetes mellitus is a main risk factor for periodontitis, but until now, the underlying molecular mechanisms remain unclear. Diabetes can increase the pathogenicity of the periodontal microbiota and the inflammatory/host immune response of the periodontium. Hyperglycemia induces reactive oxygen species (ROS) production and enhances oxidative stress (OS), exacerbating periodontal tissue destruction. Furthermore, the alveolar bone resorption damage and the epigenetic changes in periodontal tissue induced by diabetes may also contribute to periodontitis. We will review the latest clinical data on the evidence of diabetes promoting the susceptibility of periodontitis from epidemiological, molecular mechanistic, and potential therapeutic targets and discuss the possible molecular mechanistic targets, focusing in particular on novel data on inflammatory/host immune response and OS. Understanding the intertwined pathogenesis of diabetes mellitus and periodontitis can explain the cross-interference between endocrine metabolic and inflammatory diseases better, provide a theoretical basis for new systemic holistic treatment, and promote interprofessional collaboration between endocrine physicians and dentists.

Diagnostic potential of miR-200 family members in gingival crevicular fluid for chronic periodontitis: correlation with clinical parameters and therapeutic implications

OBJECTIVE

The purpose of this study was to evaluate the potential of miR-200 family members in gingival crevicular fluid (GCF) as diagnostic biomarkers for chronic periodontitis (CP), aiming to provide valuable insights for the early detection and management of the disease.

METHODS

GSE89081 dataset profiled miRNAs in GCF derived from 5 healthy and 5 periodontitis was analyzed by GEO2R. Quantitative real-time PCR was used to quantify the expression levels of miR-200 family members (miR-200a-3p, miR-200a-5p, miR-200b-3p, miR-200b-5p, miR-200c-3p, miR-200c-5p, miR-141-3p, miR-141-5p, and miR-429) in the GCF samples from 103 CP patients and 113 healthy controls. Receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic potential of miR-200 family members in differentiating CP patients from healthy controls.

RESULTS

By analyzing the GSE89081 dataset, miR-200a-5p, miR-200b-5p and miR-200c-5p were significantly upregulated in GCF of the CP patients compared to the healthy control. In this study, miR-200a-3p, miR-200a-5p, miR-200b-3p, miR-200b-5p, miR-200c-3p, miR-200c-5p were significantly increased in GCF of CP patients compared to the healthy control, while miR-141 and miR-429 did not show significant differences. MiR-200a, -200b and 200c had good diagnostic value, and when these miRNAs were combined, they demonstrated excellent diagnostic value for CP with an AUC of 0.997, sensitivity of 99.03%, and specificity of 98.23%. MiR-200a, -200b and 200c in GCF showed significant and positive correlation with plaque index (PI), gingival index (GI), bleeding on probing (BOP), clinical attachment level (CAL), and probing pocket depth (PPD).

CONCLUSION

MiR-200a, -200b and 200c in GCF may serve as potential biomarkers for the early diagnosis of CP, which was correlated with clinical parameters, being therapeutic targets for CP.

Association between Caspase-1, TNF-α Salivary Level and Their Diagnostic Potential to Discriminate Periodontitis from Healthy Control

PURPOSE

Periodontitis is associated with caspase and proinflammatory mediators, such as caspase-1 and tumor necrosis factor-alpha (TNF-α). The aim of this study was to evaluate the salivary levels of caspase-1 and TNF-α and determine their accuracy in differentiating periodontitis patients from individuals with a healthy periodontium.

MATERIALS AND METHODS

This case-control study enrolled 90 subjects, aged 30 to 55, attending the Department of Periodontics at Baghdad's outpatient clinic. Patients were initially screened to evaluate their eligibility for recruitment. After applying inclusion/exclusion criteria, subjects with a healthy periodontium were included in group 1 (controls), while subjects with periodontitis were included in group 2 (patients). The salivary levels of caspase-1 and TNF-α in participants' unstimulated saliva were measured using an enzyme-linked immunosorbent assay (ELISA). Then the periodontal status was determined using the following indices: full-mouth plaque, full-mouth bleeding on probing, probing pocket depth, clinical attachment level, and gingival recession.

RESULTS

TNF-α and caspase-1 salivary levels were higher in periodontitis patients than in healthy controls and were positively correlated with all clinical parameters. A positive significant correlation between TNF-α and caspase-1 salivary levels was noticed. For differentiating periodontal health and periodontitis, the area under the curve (AUC) values of TNF-α and caspase-1 were 0.978 and 0.998, while the proposed cut-off points were 128.163 pg/ml and 1.626 ng/ml, respectively.

CONCLUSION

The present findings supported a previous discovery that periodontitis patients have significantly higher levels of salivary TNF-α. In addition, there was a positive correlation between the salivary levels of TNF-α and caspase-1. Furthermore, caspase-1 and TNF-α showed high sensitivity and specificity in the diagnosis of periodontitis, as well as distinguishing periodontitis from periodontal health.

miR‑374a‑5p alleviates sepsis‑induced acute lung injury by targeting ZEB1 via the p38 MAPK pathway

The aim of the present study was to investigate the effects of microRNA (miR)-374a-5p on sepsis-induced acute lung injury (ALI) and the associated mechanism. Lipopolysaccharide (LPS)-induced human pulmonary microvascular endothelial cells (HPMVECs) were used to construct the cellular model of sepsis. A luciferase reporter assay was performed to confirm the association between miR-374a-5p and zinc finger E-box binding homeobox 1 (ZEB1). Reverse transcription-quantitative polymerase chain reaction and western blot analysis were performed to assess the relative expression of miR-374a-5p, ZEB1 and apoptosis-related proteins. Cell viability and apoptosis were determined by Cell Counting Kit-8 assay and flow cytometry, respectively. Enzyme-linked immunosorbent assays were used to evaluate inflammatory cytokines. The results revealed that miR-374a-5p was downregulated in sepsis patients and LPS-treated HPMVECs. Upregulation of miR-374a-5p alleviated LPS-triggered cell injury in HPMVECs, as evidenced by restoration of cell viability, and inhibition of apoptosis and the production of proinflammatory cytokines. In addition, ZEB1 was revealed to be a downstream target of miR-374a-5p, and overexpression of ZEB1 could reverse the anti-apoptotic and anti-inflammatory effects of miR-374a-5p on an LPS-induced sepsis cell model. Moreover, miR-374a-5p-induced protective effects involved the p38 MAPK signaling pathway. Collectively, miR-374a-5p exerted a protective role in sepsis-induced ALI by regulating the ZEB1-mediated p38 MAPK signaling pathway, providing a potential target for the diagnosis and treatment of sepsis.

MicroRNA-128-3p suppresses interleukin-1β-stimulated cartilage degradation and chondrocyte apoptosis via targeting zinc finger E-box binding homeobox 1 in osteoarthritis

Accumulating studies have suggested that microRNAs (miRNAs) play vital roles in the pathogenesis of osteoarthritis (OA). Nevertheless, the specific function of miR-128-3p in OA remains unknown. In this study, we demonstrated that miR-128-3p was decreased and ZEB1 was increased in OA. Additionally, miR-128-3p expression was negatively correlated with ZEB1. miR-128-3p overexpression or ZEB1 silencing attenuated extracellular matrix degradation and cell apoptosis, and increased the proliferation of IL-1β-activated CHON-001 cells. Furthermore, ZEB1 was directly targeted by miR-128-3p. In addition, ZEB1 upregulation restored the effects of miR-128-3p overexpression on OA progression. Overall, our findings suggested that miR-128-3p might regulate the development of OA via targeting ZEB1.

Transcriptional regulation of human odontogenic ameloblast-associated protein gene by tumor necrosis factor-α

OBJECTIVE

Odontogenic ameloblast-associated protein (ODAM) is produced by maturation stage ameloblasts and junctional epithelium (JE). The function of ODAM is thought to be involved in the attachment of teeth and JE. To elucidate transcriptional regulation of human ODAM gene in inflamed gingiva, we have analyzed the effects of TNF-α on the expression of ODAM gene in Ca9-22 and Sa3 gingival epithelial cells.

MATERIALS AND METHODS

Total RNAs were extracted from Ca9-22 and Sa3 cells after stimulation by TNF-α (10 ng/ml). ODAM mRNA and protein levels were analyzed by qPCR and Western blotting. Luciferase (LUC) analyses were performed using LUC constructs inserted in various lengths of ODAM gene promoter. Gel shift and chromatin immunoprecipitation (ChIP) assays were carried out.

RESULTS

TNF-α increased ODAM mRNA and protein levels at 3 to 24 h. TNF-α induced LUC activities of the ODAM gene promoter constructs, and the activities were inhibited by protein kinase A, tyrosine kinase, MEK1/2, PI3-kinase and NF-κB inhibitors. Gel shift and ChIP assays revealed that TNF-α increased CCAAT/enhancer-binding protein (C/EBP) β and Yin Yang1 (YY1) binding to three kinds of C/EBPs and YY1 elements.

CONCLUSION

These results demonstrate that TNF-α stimulates ODAM gene transcription via C/EBPs and YY1 elements in the human ODAM gene promoter.

Prediction and analysis of microRNAs involved in COVID-19 inflammatory processes associated with the NF-kB and JAK/STAT signaling pathways

COVID-19 is the cause of a pandemic associated with substantial morbidity and mortality. As yet, there is no available approved drug to eradicate the virus. In this review article, we present an alternative study area that may contribute to the development of therapeutic targets for COVID-19. Growing evidence is revealing further pathophysiological mechanisms of COVID-19 related to the disregulation of inflammation pathways that seem to play a critical role toward COVID-19 complications. The NF-kB and JAK/STAT signaling pathways are highly activated in acute inflammation, and the excessive activity of these pathways in COVID-19 patients likely exacerbates the inflammatory responses of the host. A group of non-coding RNAs (miRNAs) manage certain features of the inflammatory process. In this study, we discuss recent advances in our understanding of miRNAs and their connection to inflammatory responses. Additionally, we consider the link between perturbations in miRNA levels and the onset of COVID-19 disease. Furthermore, previous studies published in the online databases, namely web of science, MEDLINE (PubMed), and Scopus, were reviewed for the potential role of miRNAs in the inflammatory manifestations of COVID-19. Moreover, we disclosed the interactions of inflammatory genes using STRING DB and designed interactions between miRNAs and target genes using Cityscape software. Several miRNAs, particularly miR-9, miR-98, miR-223, and miR-214, play crucial roles in the regulation of NF-kB and JAK-STAT signaling pathways as inflammatory regulators. Therefore, this group of miRNAs that mitigate inflammatory pathways can be further regarded as potential targets for far-reaching-therapeutic strategies in COVID-19 diseases.

Anti‑inflammatory role of microRNA‑429 in human gingival epithelial cells‑inhibition of IL‑8 production through direct binding to IKKβ mRNA

MicroRNAs (miRNAs), a family of small non‑coding RNAs, serve a pivotal role in the regulation of the inflammation by modulating the expression of various genes. However, the molecular mechanism by which miRNAs regulate inflammation‑associated molecules in oral epithelial cells remains to be elucidated. The present study examined the biological function of miR‑429 by performing the gain‑/loss‑of‑function studies of miR‑429 in a gingival squamous cell carcinoma line Ca9‑22 cells that either over‑ or under‑expressed miR‑429 through transient transfection with miR‑429 mimic or miR‑429 inhibitor, respectively. The results demonstrated that the over‑expression of miR‑429 suppressed the mRNA level of several interleukins, including IL‑8. In addition, the over‑expression of miR‑429 reduced IL‑8 secretion under the basal and TNF‑α stimulated conditions, whereas the secretion of IL‑8 was enhanced when miR‑429 was under‑expressed. The over‑expression of miR‑429 inhibited the activation of the transcription factor NF‑κB. Furthermore, we found that miR‑429 suppressed both mRNA and protein levels of IKKβ via its direct binding to the 3'‑untranslated region of IKKβ mRNA. In addition, the downregulation of IKKβ by small interfering RNA reduced both NF‑kB activity and IL‑8 production in Ca9‑22 cells. Taken together, the findings revealed the molecular mechanism of miR‑429 to regulate the inflammatory mediator in gingival cells and suggested that it could be useful as a therapeutic target of oral inflammatory diseases.

Emerging Role of MicroRNA-200 Family in Dentistry

MicroRNAs (miRNAs) are endogenous non-coding RNAs ~22 nucleotides in length, which have been shown to participate in various biological processes. As one of the most researched miRNAs, the miR-200 family has been found to regulate several factors that are associated with the epithelial to mesenchymal transition (EMT) and cancer stem cells (CSCs) behavior. In this review, we briefly summarize the background of the miR-200 family and their implication in various dental diseases. We focus on the expression changes, biological functions, and clinical significance of the miR-200 family in oral cancer; periodontitis; oral potentially malignant disorder; gingival overgrowth; and other periodontal diseases. Additionally, we discuss the use of the miR-200 family as molecular biomarkers for diagnosis, prognostic, and therapeutic application.

Evaluation of serum and gingival crevicular fluid microRNA-223, microRNA-203 and microRNA-200b expression in chronic periodontitis patients with and without diabetes type 2

microRNA dysregulation is a reported feature of multiple pathologies, including periodontal disease, as demonstrated on cell lines, in animal models, and tissues biopsies, but serum and gingival crevicular fluid microRNA expression data in humans is scarce, especially with the diabetes (type 2) systemic complication.

OBJECTIVE

To assess serum and gingival crevicular fluid relative quantification levels of miR-223, miR-203, and miR-200b in chronic periodontitis and type 2 diabetic chronic periodontitis patients to address their possible implication in chronic periodontitis pathogenesis and its systemic complications and also to correlate their differential expression with some inflammatory (serum tumor necrosis factor-α and interleukin-10) parameters.

METHODS

Sixty subjects were recruited and divided into three groups; chronic periodontitis (n = 20), type 2 diabetic chronic periodontitis (n = 20), and healthy control (n = 20). Both serum and gingival crevicular fluid were collected from each participant for miRNA expression analysis and serum inflammatory parameters assessment.

RESULTS

A significant increase in the relative quantification levels of miR-223 and miR-200b were detected in patient groups along with a positive correlation with tumor necrosis factor-α. However, miR-203 was significantly decreased in patient groups associated with a negative correlation with tumor necrosis factor-α.

CONCLUSIONS

miR-223 and miR-200b have a potential role in chronic periodontitis pathogenesis associated with type 2 diabetes, with the ability to induce tumor necrosis factor-α secretion, while miR-203 might have a protective and healing role due to the negative correlation with the serum tumor necrosis factor-α levels found. Therefore, they may be considered as a promising therapeutic target and effective serum disease biomarkers.

MiR-200b suppresses TNF-α-induced AMTN production in human gingival epithelial cells

Amelotin (AMTN) is an enamel protein that is localized in junctional epithelium (JE) of gingiva and suggested to be involved in the attachment between JE and tooth enamel. MicroRNA is a small non-coding RNA that regulates gene expression at post-transcriptional level by binding to the 3'-untranslated region (3'-UTR) of target mRNAs. In this study, we have analyzed the effects of miR-200b on the expression of AMTN in human gingival epithelial (Ca9-22) cells. Total RNAs and proteins were extracted from Ca9-22 cells transfected with miR-200b expression plasmid or miR-200b inhibitor and stimulated by TNF-α (10 ng/ml, 12 h). AMTN and inhibitor of kappa-B kinase beta (IKKβ) mRNA and protein levels were measured by qPCR and Western blot. Human AMTN 3'-UTR that contains putative miR-200b target sites were cloned downstream of -353AMTN luciferase (LUC) plasmid. Ca9-22 cells were transfected with -353AMTN 3'-UTR LUC constructs and miR-200b expression plasmid, and LUC activities were measured with or without stimulation by TNF-α. TNF-α-induced AMTN mRNA levels were partially inhibited by miR-200b overexpression and enhanced by miR-200b inhibitor. TNF-α-induced IKKβ mRNA and protein levels were almost completely inhibited by miR-200b. Transcriptional activities of -353AMTN 3'-UTR LUC constructs were induced by TNF-α and partially inhibited by miR-200b. IKKβ inhibitor IMD0354 and NF-κB inhibitor triptolide decreased TNF-α-induced LUC activities. Furthermore, both inhibitors reduced AMTN mRNA levels in the presence or absence of TNF-α. These results suggest that miR-200b suppresses AMTN expression by targeting to AMTN and IKKβ mRNAs in the human gingival epithelial cells.

MiR-200a and miR-200b restrain inflammation by targeting ORMDL3 to regulate the ERK/MMP-9 pathway in asthma

BACKGROUND

Asthma is one of the most frequent and serious diseases worldwide. Inflammation has been reported to correlate with airway remodeling, which is critical for the progression of asthma. Better understanding of novel molecules modulating asthma and the underlying mechanism will benefit explorations of new treatments. Method: To explore the role of miR-200a and miR-200b in asthma, miR-200a mimics/inhibitor and miR-200b mimics/inhibitor were employed in A549 cells, respectively. Expression levels of inflammatory cytokines, including TNF-α, IL-4, IL-5, IL-13 and IL-1β, were measured by quantitative real time polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA). A dual luciferase reporter assay was performed to identify whether miR-200a/200b directly bound to Orosomucoid 1-like 3 (ORMDL3). ERK, p-ERK and MMP-9, involved in downstream pathways of ORMDL3, were detected using qRT-PCR and western blotting. Results: MiR-200a/200b silencing significantly increased the expression of inflammatory cytokines, including TNF-α, IL-4, IL-5, IL-13 and IL-1β, in A549 cells. ORMDL3 was the target gene of miR-200a/200b, with high expression levels in miR-200a inhibitor and miR-200b inhibitor groups. MiR-200a and miR-200b played synergistic roles in the regulation of the inflammatory effect in A549 cells. Expression levels of p-ERK and MMP-9 were significantly increased in miR-200a inhibitor and miR-200b inhibitor groups and were rescued by ERK inhibitor and MMP-9 inhibitor, respectively. Conclusion: These findings suggest that miR-200a and miR-200b are required to regulate asthma inflammation. Reduction in miR-200a/200b promotes the development of asthma inflammation by targeting ORMDL3 to activate the ERK/MMP-9 pathway. Therefore, elevating miR-200a and miR-200b and decreasing ORMDL3 might be potential strategies for inhibition of the asthma process.

miR-218 regulates diabetic nephropathy via targeting IKK-β and modulating NK-κB-mediated inflammation

Diabetic nephropathy (DN) is a common clinically relevant complication of diabetes that is associated with damage to the capillaries, yet the etiology of this condition remains unclear. Nuclear factor-kappa B (NF-κB) activation is known to be associated with DN-related inflammation and disease progression. Recent work indicated that microRNAs are diagnostic biomarkers of DN progression associated with inflammation in the progression of DN. miR-218 is known to play key regulatory roles in certain cancers in humans, while its influence on DN pathology remains uncertain. The present study, therefore, sought to assess how miR-218 influences the progression of disease in both a rat streptozotocin-induced model of DN and as well as an in vitro model system in which mouse podocytes were stimulated with high glucose levels. We found miR-218 to be markedly downregulated in both model systems relative to appropriate controls, and this downregulation was associated with IKK-β upregulation. In DN rat model, overexpressing miR-218 was sufficient to reduce renal injury. We further determined that podocyte proliferation was markedly impaired by glucose treatment, leading to the apoptotic death of these cells, and miR-218 mimics were able to reduce these phenotypes. Overexpressing miR-218 also significantly dampened inflammatory responses in this model system, as evidenced by reduced tumor necrosis factor-α, interleukin-6 (IL-6), IL-1β, and MCP-1 levels. We then confirmed that miR-218 targeting the messenger RNA encoding IKK-β using a dual-luciferase reporter assay. Together, our results provide clear evidence that miR-218 regulate NF-κB-mediated inflammation, which is central to DN progression.

Communication between EMT and PD-L1 signaling: New insights into tumor immune evasion

Immune checkpoint blockage has been considered a breakthrough in cancer treatment, achieving encouraging anti-tumor effects in some advanced solid malignancies. However, low response rate and therapeutic resistance represent significant challenges in this field. In addition to its typical role in embryonic development and tissue fibrosis, epithelial-mesenchymal transition (EMT) plays a pivotal role in tumor immunosuppression and immune evasion. Previous studies revealed that EMT is associated with activation of different immune checkpoint molecules, including PD-L1. EMT-induced immune escape promotes cancer progression and may also provide a platform for discovery of novel therapeutic approaches and predictive biomarkers for checkpoint inhibitor therapeutic response. Here, we summarize recent findings focused on EMT-induced immune suppression and evasion in the tumor microenvironment (TME). EMT transcription factors (EMT-TFs), immune cells, cell plasticity and their regulatory role in the immune response are thoroughly reviewed. Bidirectional regulation between EMT and PD-L1 signaling is discussed in terms of cancer immune escape and possible combined therapies. Additionally, we investigated the value of preclinical or clinical trials using EMT targeted therapy combined with PD-L1 inhibitors. This review may help to further understand the role of EMT and PD-L1 signaling in cancer immune evasion. Meanwhile, additional molecular mechanistic studies and clinical trials are urgently needed.

Alterations in the expression of EMT-related proteins claudin-1, claudin-4 and claudin-7, E-cadherin, TWIST1 and ZEB1 in oral lichen planus

BACKGROUND

Oral lichen planus (OLP) is a chronic T-cell-mediated inflammatory disease, which is associated with increased risk of developing oral squamous cell carcinoma. Epithelial-to-mesenchymal transition is a physiological phenomenon occurring during growth and organogenesis, but it has also an important role in tumorigenesis. In the present work, we studied the expression of known epithelial-to-mesenchymal transition markers in oral lichen planus.

METHODS

In total, 54 oral lichen planus and 22 control samples were analyzed for epithelial-to-mesenchymal transition markers. Samples were immunohistochemically stained for claudin-1, claudin-4 and claudin-7, cadherin-1 (E-cadherin), Twist-related protein 1 (TWIST1) and zinc finger E-box-binding homeobox 1 (ZEB1).

RESULTS

The expression of claudin-1, claudin-4 and E-cadherin was significantly weaker in oral lichen planus epithelium compared to controls (P < 0.001). The quantity of claudin-7-expressing cells (P < 0.001) and claudin-7 staining intensity (P < 0.05) in the stroma was greater in lichen planus than in control samples. TWIST1 and ZEB1 stainings were negative in the epithelium in both lichen planus and controls. The number of TWIST1-expressing cells in the stroma was higher in lichen planus than in controls (P < 0.001). There was a statistically significant difference in ZEB1 staining intensity in the stroma between lichen planus and control samples (P < 0.05).

CONCLUSIONS

The data indicate that the expression of claudin-1, claudin-4 and E-cadherin is decreased in oral lichen planus. This may lead to disturbance in epithelial tight junctions, cell-cell connections and epithelial permeability, contributing to oral lichen planus pathogenesis. Based on the present study, the role of TWIST1 and ZEB1 in oral lichen planus remains unclear.

RETRACTED: Quercetin ameliorates lipopolysaccharide-caused inflammatory damage via down-regulation of miR-221 in WI-38 cells

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Given the comments of Dr Elisabeth Bik regarding this article “… the Western blot bands in all 400+ papers are all very regularly spaced and have a smooth appearance in the shape of a dumbbell or tadpole, without any of the usual smudges or stains. All bands are placed on similar looking backgrounds, suggesting they were copy/pasted from other sources, or computer generated”, the journal requested the authors to provide the raw data. However, the authors were not able to fulfil this request and therefore the Editor-in-Chief decided to retract the article.