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.

MicroRNAs Function in Dental Stem Cells as a Promising Biomarker and Therapeutic Target for Dental Diseases

Undifferentiated, highly proliferative, clonogenic, and self-renewing dental stem cells have paved the way for novel approaches to mending cleft palates, rebuilding lost jawbone and periodontal tissue, and, most significantly, recreating lost teeth. New treatment techniques may be guided by a better understanding of these cells and their potential in terms of the specificity of the regenerative response. MicroRNAs have been recognized as an essential component in stem cell biology due to their role as epigenetic regulators of the processes that determine stem cell destiny. MicroRNAs have been proven to be crucial in a wide variety of molecular and biological processes, including apoptosis, cell proliferation, migration, and necrocytosis. MicroRNAs have been recognized to control protein translation, messenger RNA stability, and transcription and have been reported to play essential roles in dental stem cell biology, including the differentiation of dental stem cells, the immunological response, apoptosis, and the inflammation of the dental pulp. Because microRNAs increase dental stem cell differentiation, they may be used in regenerative medicine to either preserve the stem cell phenotype or to aid in the development of tooth tissue. The development of novel biomarkers and therapies for dental illnesses relies heavily on progress made in our knowledge of the roles played by microRNAs in regulating dental stem cells. In this article, we discuss how dental stem cells and their associated microRNAs may be used to cure dental illness.

MicroRNAs and Periodontal Disease: Helpful Therapeutic Targets?

Periodontal disease is the most common oral disease. This disease can be considered as an inflammatory disease. The immune response to bacteria accumulated in the gum line plays a key role in the pathogenesis of periodontal disease. In addition to immune cells, periodontal ligament cells and gingival epithelial cells are also involved in the pathogenesis of this disease. miRNAs which are small RNA molecules with around 22 nucleotides have a considerable relationship with the immune system affecting a wide range of immunological events. These small molecules are also in relation with periodontium tissues especially periodontal ligament cells. Extensive studies have been performed in recent years on the role of miRNAs in the pathogenesis of periodontal disease. In this review paper, we have reviewed the results of these studies and discussed the role of miRNAs in the immunopathogenesis of periodontal disease comprehensively. miRNAs play an important role in the pathogenesis of periodontal disease and maybe helpful therapeutic targets for the treatment of periodontal disease.

Anti-biofilm and bystander effects of antimicrobial photo-sonodynamic therapy against polymicrobial periopathogenic biofilms formed on coated orthodontic mini-screws with zinc oxide nanoparticles

BACKGROUND

The present study evaluated the anti-biofilm and bystander effects of antimicrobial photo-sonodynamic therapy (aPSDT) on the polymicrobial periopathogenic biofilms formed on mini-screws coated with zinc oxide nanoparticles (ZnONPs).

MATERIALS AND METHODS

Thirty orthodontic identical mini-screws were divided into 6 groups (n = 5) as follows: 1. negative control: uncoated mini-screw + phosphate-buffered saline (PBS), 2. positive control: uncoated mini-screw + 0.2% CHX, 3. coating control: coated mini-screw + PBS, 4. antimicrobial photodynamic therapy (aPDT): coated mini-screw+light emitting diode (LED), 5. Antimicrobial sonodynamic therapy (aSDT): coated mini-screw+ultrasound waves, and 6. aPSDT: coated mini-screw+LED+ultrasound waves. Electrostatic spray-assisted vapor deposition was employed to coat ZnONPs on titanium mini-screws. The biofilm inhibition test was used to assess the anti-biofilm efficacy against polymicrobial periopathogenic biofilms including Porphyromonas gingivitis, Prevotella intermedia, and Aggregatibacter actinomycetemcomitans, and the results were shown as the percent reduction of Log₁₀ colony-forming unit (CFU)/mL. Following each treatment, the gene expression levels of TNF-α, IL-1β, and IL-6 were evaluated on human gingival fibroblast (HGF) cells via quantitative real-time polymerase chain reaction (qRT-PCR) to reveal the bystander effects of aPSDT on HGF cells.

RESULTS

A significant reduction in log₁₀ CFU/mL of periopathogens was observed in groups treated with aPDT, aSDT, aPSDT, and 0.2% CHX up to 6.81, 6.63, 5.02, and 4.83 log, respectively, when compared with control groups (P<0.05). 0.2% CHX and aPSDT groups demonstrated significantly higher capacity in eliminating the periopathogen biofilm compared with other groups (P<0.05). The qRT-PCR showed that the expression level of inflammatory cytokines was significantly down regulated in aPDT, aSDT, and aPSDT groups (P<0.05).

CONCLUSION

It was found that the ZnONPs-mediated aPSDT could significantly reduce periopathogen biofilm as well as the expression level of inflammatory cytokines.

The Role of microRNAs in Inflammation

Inflammation is a biological response of the immune system to various insults, such as pathogens, toxic compounds, damaged cells, and radiation. The complex network of pro- and anti-inflammatory factors and their direction towards inflammation often leads to the development and progression of various inflammation-associated diseases. The role of small non-coding RNAs (small ncRNAs) in inflammation has gained much attention in the past two decades for their regulation of inflammatory gene expression at multiple levels and their potential to serve as biomarkers and therapeutic targets in various diseases. One group of small ncRNAs, microRNAs (miRNAs), has become a key regulator in various inflammatory disease conditions. Their fine-tuning of target gene regulation often turns out to be an important factor in controlling aberrant inflammatory reactions in the system. This review summarizes the biogenesis of miRNA and the mechanisms of miRNA-mediated gene regulation. The review also briefly discusses various pro- and anti-inflammatory miRNAs, their targets and functions, and provides a detailed discussion on the role of miR-10a in inflammation.

Anti-Inflammatory and Anti-Fibrotic Effect of Immortalized Mesenchymal-Stem-Cell-Derived Conditioned Medium on Human Lung Myofibroblasts and Epithelial Cells

Idiopathic pulmonary fibrosis (IPF) is caused by progressive lung tissue impairment due to extended chronic fibrosis, and it has no known effective treatment. The use of conditioned media (CM) from an immortalized human adipose mesenchymal stem cell line could be a promising therapeutic strategy, as it can reduce both fibrotic and inflammatory responses. We aimed to investigate the anti-inflammatory and anti-fibrotic effect of CM on human pulmonary subepithelial myofibroblasts (hPSM) and on A549 pulmonary epithelial cells, treated with pro-inflammatory or pro-fibrotic mediators. CM inhibited the proinflammatory cytokine-induced mRNA and protein production of various chemokines in both hPSMs and A549 cells. It also downregulated the mRNA expression of IL-1α, but upregulated IL-1β and IL-6 mRNA production in both cell types. CM downregulated the pro-fibrotic-induced mRNA expression of collagen Type III and the migration rate of hPSMs, but upregulated fibronectin mRNA production and the total protein collagen secretion. CM's direct effect on the chemotaxis and cell recruitment of immune-associated cells, and its indirect effect on fibrosis through the significant decrease in the migration capacity of hPSMs, makes it a plausible candidate for further development towards a therapeutic treatment for IPF.

Upregulation of microRNA-223 expression in gingival crevicular blood of women with gestational diabetes mellitus and periodontitis

Background/Purpose

MicroRNA-223 (miR-223) is involved in several inflammatory diseases, including gestational diabetes mellitus (GDM) and periodontitis. We first described a procedure for purifying miR-223 from gingival crevicular blood (GCB) of pregnant women with or without GDM and periodontitis. This study aimed to determine whether GDM and/or periodontitis modifies miR-223 expression in pregnant women and to analyze miR-223-targeted messenger RNA (mRNA) expression levels in GCB compared to peripheral blood (PB).

Materials and methods

Pregnant women were allocated to 4 groups: 10 women with GDM and periodontitis (GDM/P), 10 women with GDM without periodontitis (GDM/NP), 9 women with periodontitis and without GDM (NGDM/P) and 10 women without either condition (NGDM/NP). Clinical parameters of GDM and periodontal status were examined. GCB and PB were collected to assess miR-223, ICAM-1, IL-1β and β1-integrin gene expression by quantitative real-time polymerase chain reaction.

Results

The GDM/P group demonstrated the highest miR-223 expression levels among the 4 groups in GCB. A significant difference was found between GDM/P and GDM/NP group (P = 0.04). In contrast, the GDM/P showed the lowest miR-223 expression level in PB among the 4 groups. Moreover, ICAM-1 and IL-1β mRNA expression exhibited the opposite trend of miRNA-223, indicating that miRNA-223 might regulate the mRNA function of those genes by epigenetic events.

Conclusion

The upregulation of miR-223 expression in GCB but downregulation in PB, ICAM-1 and IL-1β genes expression in women with GDM and periodontitis suggest a promising role of miR-223 in the association between GDM and periodontitis.

Interleukin-1β regulates odontogenic ameloblast-associated protein gene transcription in human gingival epithelial cells

Junction epithelium (JE) is located apical to the bottom of the gingival sulcus and binds enamel to hemidesmosomes to protect the periodontal tissue from bacterial infection. Function of odontogenic ameloblast-associated protein (ODAM) is suggested by its expression sites (JE and maturation stage ameloblasts) to be involved in the adhesion between the JE and enamel, and odontogenesis. To analyze the changes in ODAM gene and protein expressions in inflamed gingiva, Ca9-22 gingival epithelial cells were stimulated with 1 ng/ml interleukin-1β (IL-1β) for 3-24 h, and ODAM mRNA and protein levels were analyzed by real-time PCR and Western blotting. Luciferase (LUC) constructs were made ligating various lengths of human ODAM gene promoters and performed LUC analyses in Ca9-22 cells. Gel shift and chromatin immunoprecipitation (ChIP) assays were performed. IL-1β induced ODAM mRNA and protein levels at 6-24 h. IL-1β increased LUC activities of the ODAM gene promoter constructs from - 85 to - 950. These activities were blocked by protein kinase A, tyrosine kinase, mitogen-activated protein (MAP) kinase kinase and phosphoinositide 3-kinase inhibitors. Gel shift and ChIP assays showed that IL-1β induced CCAAT/enhancer-binding protein (C/EBP) β and Yin Yang1 (YY1) binding to C/EBP1, 2, 3, and YY1 elements. These data indicate that IL-1β stimulates ODAM gene transcription mediated through C/EBP1, C/EBP2, C/EBP3, and YY1 elements in the human ODAM gene promoter.

Inflammatory Biomarkers in Addictive Disorders

Substance use disorders are a group of diseases that are associated with social, professional, and family impairment and that represent a high socio-economic impact on the health systems of countries around the world. These disorders present a very complex diagnosis and treatment regimen due to the lack of suitable biomarkers supporting the correct diagnosis and classification and the difficulty of selecting effective therapies. Over the last few years, several studies have pointed out that these addictive disorders are associated with systemic and central nervous system inflammation, which could play a relevant role in the onset and progression of these diseases. Therefore, identifying different immune system components as biomarkers of such addictive disorders could be a crucial step to promote appropriate diagnosis and treatment. Thus, this work aims to provide an overview of the immune system alterations that may be biomarkers of various addictive disorders.

The Role of microRNAs in Pulp Inflammation

The dental pulp can be affected by thermal, physical, chemical, and bacterial phenomena that stimulate the inflammatory response. The pulp tissue produces an immunological, cellular, and vascular reaction in an attempt to defend itself and resolve the affected tissue. The expression of different microRNAs during pulp inflammation has been previously documented. MicroRNAs (miRNAs) are endogenous small molecules involved in the transcription of genes that regulate the immune system and the inflammatory response. They are present in cellular and physiological functions, as well as in the pathogenesis of human diseases, becoming potential biomarkers for diagnosis, prognosis, monitoring, and safety. Previous studies have evidenced the different roles played by miRNAs in proinflammatory, anti-inflammatory, and immunological phenomena in the dental pulp, highlighting specific key functions of pulp pathology. This systematized review aims to provide an understanding of the role of the different microRNAs detected in the pulp and their effects on the expression of the different target genes that are involved during pulp inflammation.

Inducing Apoptosis and Suppressing Inflammatory Reactions in Synovial Fibroblasts are Two Important Ways for Guizhi-Shaoyao-Zhimu Decoction Against Rheumatoid Arthritis

Background and Objectives

Guizhi-Shaoyao-Zhimu decoction (GSZD) is often applied to control rheumatoid arthritis (RA), gout, osteoarthritis, etc. In this study, bioinformatic analysis and experimental verification were used to uncover the integral mechanism profile of GSZD against RA.

Materials and Methods

The chemical compositions of GSZD were identified by UPLC-QTOF-MS/MS. MH7A cell model was established to screen active compounds in GSZD, and potential targets of these compounds were predicted through online database retrieval. The differential expression genes (DEGs) in synovial tissue of RA patients and normal controls were retrieved from the GEO database. DEGs and the predicated compounds targets were overlapped, and the overlapped genes were subsequently enriched by GO and KEGG analysis. The pathways with significant enrichments were further experimentally verified.

Results

A total of 19 constituents were identified from GSZD, and 11 compounds showed obviously antiproliferative effects on MH7A cells with IC₅₀ < 100 μg/mL. Bioinformatic analysis indicated that IL-1β, IL-6, MAPK8, JAK2, CXCL8, and CASP3 were the main targets of GSZD, and the integral pharmacological mechanisms profile of GSZD might be related to anti-inflammation and proapoptosis. GSZD can promote the loss of mitochondrial membrane potential (MOMP) and induce apoptosis in MH7A cells. Furthermore, in vitro experiments showed GSZD can not only downregulate mRNA expressions of IL-1β (p<0.05), IL-6 (p<0.05), MMPs (p<0.05) and CCL5 (p<0.05) but also inhibit the nuclear transcription of NF-κB. GSZD also reduced the expressions of Bcl-2 (p<0.05), JAK2 (p<0.05), STAT-3 (p<0.05), whereas increase Bax (p<0.05), Caspase-3 (p<0.05) and caspase-9 (p<0.05).

Conclusion

Collectively, inducing synovial fibroblast apoptosis and inhibiting inflammatory response are two important ways for GSZD to RA, and our study proved bioinformatic analysis combined with experimental verification is a feasible method to explore the drug targets and mechanism of actions of TCMs.

Kuijieling decoction suppresses NLRP3-Mediated pyroptosis to alleviate inflammation and experimental colitis in vivo and in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Ulcerative colitis (UC) is an autoimmune disease. Although the mortality rate of UC is not very high, it has a considerable morbidity rate and an unsatisfactory cure rate. Without effective treatment, UC is likely to develop into colon cancer. Kuijieling (KJL) is an effective empirical formula to treat UC in the clinical setting, and it has been proven to have curative effects against UC.

AIM OF THE STUDY

In a previous study, we demonstrated that KJL could suppress NOD-like receptor protein 3 (NLRP3) to reduce inflammatory cytokines and alleviate UC. In this study, we investigated the mechanism of KJL in more detail, from the perspective of pyroptosis.

MATERIALS AND METHODS

We established a dextran sulfate sodium-induced UC mouse model and RAW264.7 cells to measure different indicators with different experimental methods. The efficiency of KJL was evaluated by measuring the length and unit weight of mouse colons, and assessment of pathological injury was performed using HE staining. We detected different expression levels of NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), caspase-1, gasdermin-D C-terminal domain (GSDMD-C), gasdermin-D N-terminal domain (GSDMD-N), IL-1β, and IL-18 in colon tissues and cells using RT-qPCR and western blotting. Immunohistochemistry was used for tissues and immunofluorescence for cells to confirm protein expression. IL-1β and IL-18 were measured with enzyme-linked immunosorbent assay in serum, tissue, and cell culture supernatant. MiR-223 was detected using RT-qPCR.

RESULTS

After administration of KJL suspension, colon damage in KJL groups was milder than in model groups. ASC, caspase-1, IL-1β, and IL-18 mRNA levels in colon tissue were decreased to different degrees in the KJL groups. Protein expression of NLRP3, caspase-1, GSDMD-N, IL-1β, and IL-18 in vivo decreased significantly in the KJL groups. In addition, Mir-223 level decreased in colon tissue of the KJL groups. In vitro, NLRP3, ASC, caspase-1, GSDMD-N, IL-1β, and IL-18 levels decreased to varying degrees, at both mRNA and protein levels. Mir-223 was lower in the KJL groups than in the model group. Furthermore, KJL was shown to regulate the level of miR-223, which returned to normal after its expression was inhibited or promoted, and the levels of associated indicators also returned to normal after transfection.

CONCLUSIONS

KJL is able to inhibit pyroptosis to alleviate UC, but these suppression effects were not mediated through miR-223 regulation.

The mechanism of miR-363-3p/DUSP10 signaling pathway involved in the gastric mucosal injury induced by clopidogrel

Clopidogrel-induced gastric injury is an important clinical problem. However, the exact mechanism is still unclarified. Increasing evidence indicates that miRNAs may be involved in the pathogenesis of gastric mucosal injury. In this study, the aim was to investigate the role of miR-363-3p in the gastric mucosal injury caused by clopidogrel. MiRNA microarray analysis was performed using paired gastric mucosal in order to find differential expression of miRNAs. The levels of miR-363-3p were examined in gastric mucosal injury caused by clopidogrel. The GES-1 cells were used as a model system, miR-363-3p mimic/inhibitor was transfected into GES-1 cells, then GES-1 cells were treated with clopidogrel. The levels of miR-363-3p and DUSP10 were examined in GES-1 cells using quantitative real-time PCR (qRT-PCR). CCK-8 assay and flow cytometry analysis were used to detect cell proliferation and apoptosis, respectively. Western blot assay was used to measure the protein levels of DUSP10. The interaction between miR-363-3p and DUSP10 was determined by luciferase reporter assay. MiR-363-3p was selected as a differentially expressed miRNA. The expression of miR-363-3p in gastric mucosal injury caused by clopidogrel was higher than that in normal samples. Also, depletion of miR-363-3p increased the proliferation of GES-1 cells and reduced the apoptosis. Luciferase-reporting assay results confirmed that DUSP10 was one of the target genes of miR-363-3p. DUSP10 inhibited apoptosis in GES-1 cells treated by clopidogrel. Moreover, DUSP10 knockdown abrogated the inhibitory effects on apoptosis in GES-1 cells mediated by miR-363-3p inhibitor. Knockdown of miR-363-3p increased the proliferation and reduced the apoptosis by targeting DUSP10 in GES-1 cells treated by clopidogrel, indicating that miR-363-3p may be a potential therapeutic target for gastric mucosal injury caused by clopidogrel.

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.

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.

Mechanistic Actions of microRNAs in Diabetic Wound Healing

Wound healing is a complex biological process that is impaired under diabetes conditions. Chronic non-healing wounds in diabetes are some of the most expensive healthcare expenditures worldwide. Early diagnosis and efficacious treatment strategies are needed. microRNAs (miRNAs), a class of 18-25 nucleotide long RNAs, are important regulatory molecules involved in gene expression regulation and in the repression of translation, controlling protein expression in health and disease. Recently, miRNAs have emerged as critical players in impaired wound healing and could be targets for potential therapies for non-healing wounds. Here, we review and discuss the mechanistic background of miRNA actions in chronic wounds that can shed the light on their utilization as specific wound healing 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.

miRNA-223 at the crossroads of inflammation and cancer

miR-223 is an evolutionarily conserved anti-inflammatory microRNA primarily expressed in myeloid cells. miR-223 post-transcriptionally regulates many genes essential in inflammation, cell proliferation, and invasion. Recent studies show that miR-223 is either endogenously expressed or transferred in exosomes or extracellular vesicles to non-phagocytic cells including cancer cells, where it exerts biological functions. In cancerous cells, miR-223 acts either as an oncomiR promoting tumors or as a tumor suppressor in a context-dependent manner. Taken together, miR-223 can regulate tumorigenesis at multiple levels, including by suppressing the inflammatory tumor microenvironment and modulating malignancy of cancer cells.

Effects of interleukin-1β on human follicular dendritic cell-secreted protein gene expression in periodontal ligament cells

Follicular dendritic cell-secreted protein (FDC-SP) is expressed in FDCs, human periodontal ligament (HPL) cells, and junctional epithelium. To evaluate the effects of interleukin-1 beta (IL-1β) on FDC-SP gene expression in immortalized HPL cells, FDC-SP mRNA and protein levels in HPL cells following stimulation by IL-1β were measured by real-time polymerase chain reaction and Western blotting. Luciferase (LUC), gel mobility shift, and chromatin immunoprecipitation (ChIP) analyses were performed to study the interaction between transcription factors and promoter regions in the human FDC-SP gene. IL-1β (1 ng/mL) induced the expression of FDC-SP mRNA and protein levels at 3 h, and reached maximum levels at 12 h. IL-1β increased LUC activities of constructs (-116FDCSP - -948FDCSP) including the FDC-SP gene promoter. Transcriptional inductions by IL-1β were partially inhibited by 3-base-pair (3-bp) mutations in the Yin Yang 1 (YY1), GATA, CCAAT-enhancer-binding protein2 (C/EBP2), or C/EBP3 in the -345FDCSP. IL-1β-induced -345FDCSP activities were inhibited by protein kinase A, tyrosine-kinase, mitogen-activated protein kinase (MEK)1/2, and PI3-kinase inhibitors. The results of gel shift and ChIP assays revealed that YY1, GATA, and C/EBP-β interacted with the YY1, GATA, C/EBP2, and C/EBP3 elements that were increased by IL-1β. These studies demonstrate that IL-1β increases FDC-SP gene transcription in HPL cells by targeting YY1, GATA, C/EBP2, and C/EBP3 in the human FDC-SP gene promoter.

Inflammation-induced overexpression of microRNA-223-3p regulates odontoblastic differentiation of human dental pulp stem cells by targeting SMAD3

AIM

To profile miRNA expression between inflamed and healthy human dental pulp tissues and to investigate how the upregulation of miR-223-3p in the inflamed pulp tissue regulates odontoblast differentiation and regeneration.

METHODOLOGY

Microarray analysis was used to identify differences in miRNA expression patterns between healthy and inflamed pulp tissue. The results were validated using quantitative real-time PCR. To determine the effect of miR-223-3p on odontoblast differentiation, miR-223-3p was overexpressed in human dental pulp stem cells (DPSCs), which were cultured in mineralizing induction medium (to induce odontoblast differentiation). To identify the target genes of miR-223-3p, an SABiosciences Human Osteogenesis PCR Array, combined with bioinformatics, was used. Furthermore, a dual-luciferase reporter assay and a small interfering RNA (siRNA) experiment were used to confirm the relationship between miR-223-3p and its target gene. Statistical analysis was performed using the Student's t-test or one-way analysis of variance (anova); P < 0.05 was considered statistically significant.

RESULTS

Seventy-nine miRNAs were significantly differentially expressed (fold change >2.0; P < 0.05) between the two tissues. In particular, miR-223-3p was markedly upregulated in inflamed dental pulp. Overexpression of miR-223-3p in DPSCs significantly increased the protein levels of dentine sialophosphoprotein (DSPP) and dentine matrix protein 1 (DMP-1) (P < 0.05). However, the SMAD family member 3 (SMAD3) protein level was significantly lower than in control DPSCs (P < 0.05). Bioinformatics and the dual-luciferase assay reporter assay indicated that Smad3 was a potential target of miR-223-3p. Knockdown of Smad3 in DPSCs subjected to mineralization induction resulted in detection of DSPP and DMP-1 earlier than in control DPSCs, and it increased the protein level of alkaline phosphatase (ALP), thereby promoting odontoblast differentiation.

CONCLUSIONS

miR-223-3p is implicated in the regulation of odontoblast differentiation, which may be involved in the process of pulpitis repair.

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

OBJECTIVE

MicroRNAs (miRNAs) play important roles in biological processes such as cell differentiation, development, infection, immune response, inflammation and tumorigenesis. We previously reported that the expression of miR-200b was significantly increased in inflamed gingiva compared with non-inflamed gingiva. To elucidate the roles of miR-200b in the inflamed gingiva, we have analyzed the effects of miR-200b on the expression of IL-6 in human gingival fibroblasts (HGF).

MATERIALS AND METHODS

Total RNA and protein were extracted from HGF after stimulation by interleukin-1β (IL-1β; 1 ng/ml) or tumor necrosis factor-α (TNF-α; 10 ng/ml) and transfected with miR-200b expression plasmid or miR-200b inhibitor. IL-6, IL-1β, inhibitor of nuclear factor kappa-B kinaseβ (IKKβ), Zinc-finger E-box-binding homeobox 1 (ZEB1) and E-cadherin mRNA and protein levels were analyzed by real-time PCR and Western blot.

RESULTS

IL-1β and TNF-α increased IL-6 mRNA and protein levels, and they were significantly suppressed by miR-200b overexpression, whereas they were further increased by miR-200b inhibitor in HGF. IKKβ and ZEB1 which are target genes of miR-200b negatively regulate E-cadherin. MiR-200b suppressed the expression of IKKβ and ZEB1 and increased E-cadherin mRNA and protein levels in HGF.

CONCLUSIONS

These results suggest that miR-200b attenuates inflammatory response via IKKβ and ZEB1 in periodontal tissue.

Anti-Inflammatory MicroRNAs and Their Potential for Inflammatory Diseases Treatment

Inflammation is a complicated biological and pathophysiological cascade of responses to infections and injuries, and inflammatory mechanisms are closely related to many diseases. The magnitude, the complicated network of pro- and anti-inflammatory factors, and the direction of the inflammatory response can impact on the development and progression of various disorders. The currently available treatment strategies often target the symptoms and not the causes of inflammatory disease and may often be ineffective. Since the onset and termination of inflammation are crucial to prevent tissue damage, a range of mechanisms has evolved in nature to regulate the process including negative and positive feedback loops. In this regard, microRNAs (miRNAs) have emerged as key gene regulators to control inflammation, and it is speculated that they are fine-tune signaling regulators to allow for proper resolution and prevent uncontrolled progress of inflammatory reactions. In this review, we discuss recent findings related to significant roles of miRNAs in immune regulation, especially the potential utility of these molecules as novel anti-inflammatory agents to treat inflammatory diseases. Furthermore, we discuss the possibilities of using miRNAs as drugs in the form of miRNA mimics or miRNA antagonists.

Mutant cartilage oligomeric matrix protein (COMP) compromises bone integrity, joint function and the balance between adipogenesis and osteogenesis

Mutations in COMP (cartilage oligomeric matrix protein) cause severe long bone shortening in mice and humans. Previously, we showed that massive accumulation of misfolded COMP in the ER of growth plate chondrocytes in our MT-COMP mouse model of pseudoachondroplasia (PSACH) causes premature chondrocyte death and loss of linear growth. Premature chondrocyte death results from activation of oxidative stress and inflammation through the CHOP-ER pathway and is reduced by removing CHOP or by anti-inflammatory or antioxidant therapies. Although the mutant COMP chondrocyte pathologic mechanism is now recognized, the effect of mutant COMP on bone quality and joint health (laxity) is largely unknown. Applying multiple analytic approaches, we describe a novel mechanism by which the deleterious consequences of mutant COMP retention results in upregulation of miR-223 disturbing the adipogenesis - osteogenesis balance. This results in reduction in bone mineral density, bone quality, mechanical strength and subchondral bone thickness. These, in addition to abnormal patterns of ossification at the ends of the femoral bones likely contribute to precocious osteoarthritis (OA) of the hips and knees in the MT-COMP mouse and PSACH. Moreover, joint laxity is compromised by abnormally thin ligaments. Altogether, these novel findings align with the PSACH phenotype of delayed ossification and bone age, extreme joint laxity and joint erosion, and extend our understanding of the underlying processes that affect bone in PSACH. These results introduce a novel finding that miR-223 is involved in the ossification defect in MT-COMP mice making it a therapeutic target.

MicroRNA profiling in gingival crevicular fluid of periodontitis-a pilot study

Periodontitis is a chronic inflammatory disease that affects the interface of teeth and surrounding tissues. Gingival crevicular fluid (GCF) is an exudate of the periodontal tissues and can be collected from the gap between the tooth and gum (gingival sulcus or periodontal pocket) with paper strips. Testing of GCF is a low‐cost and minimally invasive procedure. In a variety of diseases, microRNAs (miRNAs) in body fluids are implicated in pathogenesis, and are suggested as potential diagnostic biomarkers. Here, we profiled miRNAs in GCF (two chronic periodontitis, one aggressive periodontitis, and five healthy subjects) using miRCURY LNA™ Universal RT microRNA PCR System, which yielded quantitative measures of more than 600 miRNAs. Through this analysis, we found that miRNA profiles in GCF of periodontitis patients are distinct from those of healthy controls. We further selected 40 miRNAs and confirmed their differential expression patterns in different subjects (five chronic periodontitis, one aggressive periodontitis, and six healthy subjects) using a custom miRNA PCR panel. This is the first demonstration of miRNA profiling in GCF and its alteration in periodontitis. Our findings suggest that a subset of miRNAs in GCF holds potential as a biomarker for periodontitis.

MicroRNA-195-5p Regulates Osteogenic Differentiation of Periodontal Ligament Cells Under Mechanical Loading

Osteogenic differentiation and bone formation are tightly regulated by several factors, including microRNAs (miRNAs). However, miRNA expression patterns and function during mechanical loading-induced osteogenic differentiation of human periodontal ligament cells (PDLCs) remain unclear. Here, we investigated the differential expression of miRNA-195-5p in the periodontal tissues of mice under orthodontic mechanical loading and in primary human PDLCs exposed to a simulated tension strain. The miR-195-5p was observed to be down-regulated and negatively correlated with osteogenic differentiation. Overexpression of miR-195-5p significantly inhibited PDLC differentiation under cyclic tension strain (CTS), whereas the functional inhibition of miR-195-5p yielded an opposite effect. Further experiments confirmed that WNT family member 3A (WNT3A), fibroblast growth factor 2 (FGF2), and bone morphogenetic protein receptor-1A (BMPR1A), proteins important for osteogenic activity and stability, were direct targets of miR-195-5p. Mechanical loading increased the WNT3A, FGF2, and BMPR1A protein levels, while miR-195-5p inhibited WNT3A, FGF2, and BMPR1A protein expression. WNT, FGF, and BMP signaling were involved in osteogenic differentiation of PDLCs under CTS. Further study confirmed that reintroduction of WNT3A and BMPR1A can rescue the inhibition of miR-195-5p on osteogenic differentiation of PDLCs. Our findings are the first to demonstrate that miR-195-5p is a mechanosensitive gene that plays an important role in mechanical loading-induced osteogenic differentiation and bone formation.

Interleukin-6-174G/C Polymorphism Contributes to Periodontitis Susceptibility: An Updated Meta-Analysis of 21 Case-Control Studies

Introduction. Chronic Periodontitis (CP) is suggested to be related to gene variations. Present study aims to quantitatively estimate the association between interleukin-6- (IL-6-) 174G/C polymorphism and CP susceptibility. Materials and Methods. Pubmed, Embase, and Web of Science were searched up to May 2016. The meta-analyses were performed using STATA 12.0. Results. 21 studies were yielded. Significant associations were found under heterozygote comparison and dominant model in studies fulfilling HWE (GC versus GG: OR = 0.690, 95% CI = 0.560–0.849, P = 0.000; CC + GC versus GG: OR = 0.690, 95% CI = 0.568–0.838, P < 0.001); significant associations were found under heterozygote comparison and dominant model in Caucasian studies fulfilling HWE (GC versus GG: OR = 0.752, 95% CI = 0.577–0.980, P = 0.035; CC + GC versus GG: OR = 0.737, 95% CI = 0.576–0.944, P = 0.016); significant associations were found under allele comparison, heterozygote comparison, and dominant model in Brazilian population (C versus G: OR = 0.648, 95% CI = 0.497–0.845, P = 0.001; GC versus GG: OR = 0.621, 95% CI = 0.441–0.876, P = 0.007; CC + GC versus GG: OR = 0.649, 95% CI = 0.470–0.896, P = 0.009). Conclusion. IL-6 174 polymorphism is associated with CP susceptibility. In Brazilian and Caucasian population, IL-6 174 GG genotype plays as a risk factor to CP.

Vitamin D-Regulated MicroRNAs: Are They Protective Factors against Dengue Virus Infection?

Over the last few years, an increasing body of evidence has highlighted the critical participation of vitamin D in the regulation of proinflammatory responses and protection against many infectious pathogens, including viruses. The activity of vitamin D is associated with microRNAs, which are fine tuners of immune activation pathways and provide novel mechanisms to avoid the damage that arises from excessive inflammatory responses. Severe symptoms of an ongoing dengue virus infection and disease are strongly related to highly altered production of proinflammatory mediators, suggesting impairment in homeostatic mechanisms that control the host's immune response. Here, we discuss the possible implications of emerging studies anticipating the biological effects of vitamin D and microRNAs during the inflammatory response, and we attempt to extrapolate these findings to dengue virus infection and to their potential use for disease management strategies.