Evaluation of Tumorigenic Properties of MDA-MB-231 Cancer Stem Cells Cocultured with Telocytes and Telocyte-Derived Mitochondria Following miR-146a Inhibition

Telocytes have some cytoplasmic extensions called telopodes, which are thought to play a role in mitochondrial transfer in intercellular communication. Besides, it is hypothesized that telocytes establish cell membrane-mediated connections with breast cancer cells in coculture and may contribute to the survival of neoplastic cell clusters together with other stromal cells. The aim of this study is to investigate the contribution of telocytes and telocyte-derived mitochondria, which have also been identified in breast tumors, to the tumor development of breast cancer stem cells (CSCs) via miR-146a-5p. The isolation/characterization of telocytes from bone marrow mononuclear cells and the isolation of mitochondria from these cells were performed, respectively. In the next step, CSCs were isolated from the MDA-MB-231 cell line and were characterized. Then, miR-146a-5p expressions of CSCs were inhibited by anti-miR-146a-5p. The epithelial-mesenchymal transition (EMT) was determined by evaluating changes in vimentin protein levels and was evaluated by analyzing BRCA1, P53, SOX2, E-cadherin, and N-cadherin gene expression changes. Our results showed that miR-146a promoted stemness and oncogenic properties in CSCs. EMT (N-cadherin, vimentin, E-cadherin) and tumorigenic markers (BRCA1, P53, SOX2) of CSCs decreased after miR-146a inhibition. Bone marrow-derived telocytes and mitochondria derived from telocytes favored the reduction of CSC aggressiveness following this inhibition.

InflammamiRs in focus: Delivery strategies and therapeutic approaches

microRNAs (miRNAs) are small non-protein-coding RNAs which are essential regulators of host genome expression at the post-transcriptional level. There is evidence of dysregulated miRNA expression patterns in a wide variety of diseases, such as autoimmune and inflammatory conditions. These miRNAs have been termed "inflammamiRs." When working with miRNAs, the method followed, the approach to treat or diagnosis, and the selected biological material are very crucial. Demonstration of the role of miRNAs in particular disease phenotypes facilitates their evaluation as potential and effective therapeutic tools. A growing number of reports suggest the significant utility of miRNAs and other small RNA drugs in clinical medicine. Most miRNAs seem promising therapeutic options, but some features associated with miRNA therapy like off-target effect, effective dosage, or differential delivery methods, mainly caused by the short target's sequence, make miRNA therapies challenging. In this review, we aim to discuss some of the inflammamiRs in diseases associated with inflammatory pathways and the challenge of identifying the most potent therapeutic candidates and provide a perspective on achieving safe and targeted delivery of miRNA therapeutics. We also discuss the status of inflammamiRs in clinical trials.

The role of telocytes and miR-21-5p in tumorigenicity and metastasis of breast cancer stem cells

BACKGROUND

This study aims to investigate the roles of telocytes on the metastatic properties of breast cancer stem cells (CSCs), and to re-evaluate the effect of miR-21-5p expression on CSCs following the addition of telocytes.

METHODS AND RESULTS

Telocytes from human bone marrow mononuclear cells were isolated/characterised. This was followed by the isolation/characterisation of CSCs from the MDA-MB-231. miR-21-5p was both overexpressed/inhibited in CSCs. Through co-culture studies, EMT transition and oncogenic properties of CSCs were investigated by analysing changes in ALDH1 and vimentin protein levels as well as changes in the ABCC11, SNAI1, LZTFL1, Oct 3/4, E- and N-cadherin gene expression levels. With the inhibition of miR-21-5p, significant increases in LZTFL and ABCC11 were observed with the addition of telocytes. The expression of the LZTFL gene, which decreased with the overexpression of miR-21-5p, increased in CSCs after co-culture with telocytes. While an increase expression of ABCC11, SNAI1, N-Cadherin, vimentin and ALDH was observed in CSCs after overexpression of miR-21-5p, significant decreases in these expressions were observed after co-culture with telocyte.

CONCLUSIONS

In our study, by gene/protein level analysis we demonstrated that telocytes may have the potential to reduce cancer metastasis through miR-21-5p in breast cancer progression and reduce EMT transition.

Characterization of serum extracellular vesicles and their differential level of miR-197-3p in familial Mediterranean fever patients

OBJECTIVES

The aim of this study was to analyze the existence of miRNAs derived from serum extracellular vesicles (EVs) in familial Mediterranean fever (FMF) patients. Our group has previously shown the association of certain miRNAs with FMF.

METHODS

Serum samples of adult and pediatric FMF patients and their age matched controls were used in the study. Serum EVs were characterized by transmission electron microscopy (TEM) and flow cytometry. RNAs were isolated from EVs and levels of miR-197-3p and miR-20a-5p were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR).

RESULTS

EV characterization using TEM demonstrated fraction of 30-120 nm-sized particles with cup-shaped morphology. Flow cytometry results revealed the CD63 and CD81 positive populations as 53.3% in serum EVs. We showed that miR-197-3p and miR-20a-5p were "circulating miRNAs" and carried in EVs of FMF patients and controls. In FMF patients, level of miR-197-3p was significantly decreased. There was no significant alteration in the level for miR-20a-5p between patients and controls.

CONCLUSION

We showed the differential level of miR-197-3p in serum EVs of the FMF patients. miR-197-3p's potential as a biomarker and therapeutic target in FMF pathogenesis warrants further investigation.

Drug metabolism and inflammation related distinct miRNA signature of colchicine resistant familial Mediterranean fever patients

OBJECTIVE

Colchicine is the primary treatment for familial Mediterranean fever (FMF). Although colchicine is safe and effective in FMF patients, around 5-10% of patients show resistance to the drug. This study investigates the possibility of a link between colchicine resistance and the distinct miRNA profiles in colchicine resistant FMF patients.

METHODS

Differentially expressed miRNAs in colchicine resistant FMF patients were detected by Affymetrix 4.0 miRNA array analysis. These miRNAs were then categorized based on the role of their target genes in drug metabolism and inflammation related pathways. qRT-PCR was used to validate candidate miRNAs selected by Enrichr, a gene enrichment analysis system based on the relevance of possible target genes in drug metabolism pathways. Expression levels of these miRNAs' potential target genes were investigated by qRT-PCR. Then, a colchicine resistant hepatoblastoma cell line (HEPG2) was established, and the differentially expressed miRNAs and genes identified in patients were also analyzed in this colchicine-resistant cell line.

RESULTS

25 differentially expressed miRNAs were detected in colchicine resistant FMF patients. miR-183-5p, miR-15b-5p, miR-505-5p, and miR-125a-5p were identified to be associated with drug resistance and inflammatory pathways and thus chosen for further validation. miR-183-5p, miR-15b-5p, miR-505-5p miRNAs showed significantly differential expression in qRT-PCR. NFKB1, NR3C1, PPARα - drug absorption, distribution, metabolism, and excretion (ADME) genes were predicted to be targeted by these miRNAs. Among these targets, NFKB1 and NR3C1 were differentially over expressed in colchicine resistant FMF patients. These findings were validated in the colchicine resistant hepatoblastoma cell line (HEPG2).

CONCLUSION

This is the first study evaluating the role of miRNAs in colchicine resistant patients with FMF. Their differential expression may result in resistance to standard colchicine treatment by affecting the expression of genes that take place in drug absorption, distribution, metabolism, and excretion (ADME) or nuclear receptors that regulate ADME genes, thus potentially playing a role in both drug metabolism and inflammation.

Dysregulation of miRNA-30e-3p targeting IL-1β in an international cohort of systemic autoinflammatory disease patients

Autoinflammation is the standard mechanism seen in systemic autoinflammatory disease (SAID) patients. This study aimed to investigate the effect of a candidate miRNA, miR-30e-3p, which was identified in our previous study, on the autoinflammation phenotype seen in SAID patients and to analyze its expression in a larger group of European SAID patients. We examined the potential anti-inflammatory effect of miR-30e-3p, which we had defined as one of the differentially expressed miRNAs in microarray analysis involved in inflammation-related pathways. This study validated our previous microarray results of miR-30e-3p in a cohort involving European SAID patients. We performed cell culture transfection assays for miR-30e-3p. Then, in transfected cells, we analyzed expression levels of pro-inflammatory genes; IL-1β, TNF-α, TGF-β, and MEFV. We also performed functional experiments, caspase-1 activation by fluorometric assay kit, apoptosis assay by flow cytometry, and cell migration assays by wound healing and filter system to understand the possible effect of miR-30e-3p on inflammation. Following these functional assays, 3'UTR luciferase activity assay and western blotting were carried out to identify the target gene of the aforementioned miRNA. MiR-30e-3p was decreased in severe European SAID patients like the Turkish patients. The functional assays associated with inflammation suggested that miR-30e-3p has an anti-inflammatory effect. 3'UTR luciferase activity assay demonstrated that miR-30e-3p directly binds to interleukin-1-beta (IL-1β), one of the critical molecules of inflammatory pathways, and reduces both RNA and protein levels of IL-1β. miR-30e-3p, which has been associated with IL-1β, a principal component of inflammation, might be of potential diagnostic and therapeutic value for SAIDs. KEY MESSAGES: miR-30e-3p, which targets IL-1β, could have a role in the pathogenesis of SAID patients. miR-30e-3p has a role in regulating inflammatory pathways like migration, caspase-1 activation. miR-30e-3p has the potential to be used for future diagnostic and therapeutic approaches.

Inflammation-related differentially expressed common miRNAs in systemic autoinflammatory disorders patients can regulate the clinical course

OBJECTIVES

Systemic autoinflammatory diseases (SAIDs) are caused by the malfunctioning of the innate immune system factors. Clinical heterogeneity and undefined pathobiology are common phenomena among SAIDs. In this study, we aimed to assess the involvement of microRNAs in regulating these complex diseases.

METHODS

The expression pattern of different miRNAs was compared between SAID patients with high autoinflammatory disease activity index (AIDAI) score and with low AIDAI score, and their role in inflammation-related pathways was investigated. Differentially expressed miRNAs were determined using the Multi Experiment Viewer (MEV) and Transcriptome Analysis Console (TAC) analysis tools using miRNA microarray. Potential targets of miRNAs were enriched for inflammation-related genes and validated using qRT-PCR analysis.

RESULTS

Upon performing microarray analysis, 40 differentially expressed miRNAs were identified between mild familial Mediterranean fever (FMF) patients and severe SAID patients. Thereafter, 21 of 40 miRNAs were found to be potentially involved in inflammatory pathways, of which, 8 were further validated through qRT-PCR. The targets of these 8 miRNAs (miR-29b-3p, miR-29c-3p, miR-30e-3p, miR-130b-3p, miR-148a-3p, miR-186-5p, miR-197-3p, and miR-374b-5p) belonged to the inflammation-related genes and pathways.

CONCLUSIONS

This is the first study to identify miRNAs that might be associated with a more severe disease form of monogenic autoinflammatory diseases. All these miRNAs were associated with cytokine-mediated pathways and might be used for establishing diagnostic and therapeutic methods.

The Common miRNA Signatures Associated with Mitochondrial Dysfunction in Different Muscular Dystrophies

Secondary mitochondrial damage in skeletal muscles is a common feature of different neuromuscular disorders, which fall outside the mitochondrial cytopathies. The common cause of mitochondrial dysfunction and structural changes in skeletal muscle tissue remains to be discovered. Although they are associated with different clinical, genetic, and pathologic backgrounds, the pathomechanisms underlying neuromuscular disorders might be attributed to the complex interaction and cross talk between mitochondria and the associated miRNAs. This study aimed to identify the common miRNA signatures that are associated with mitochondrial damage in different muscular dystrophies (MDs; Duchenne muscular dystrophy, megaconial congenital muscular dystrophy, Ullrich congenital muscular dystrophy, and α-dystroglycanopathy). The miRNome profiles of skeletal muscle biopsies acquired from four different MD groups and control individuals were analyzed by miRNA microarray. We identified 17 common up-regulated miRNAs in all of the tested MD groups. A specific bioinformatics approach identified 10 of these miRNAs to be specifically related to the mitochondrial pathways. Six miRNAs, miR-134-5p, miR-199a-5p, miR-382-5p, miR-409-3p, miR-497-5p, and miR-708-5p, were associated with the top four mitochondrial pathways and were thus selected as priority candidates for further validation by quantitative real-time PCR analysis. We demonstrate, for the first time, common up-regulated miRNAs that are associated with mitochondrial damage in different MD groups, therefore contributing to the pathophysiology. Our findings may open a new gate toward therapeutics.

Autoinflammation in addition to combined immunodeficiency: SLC29A3 gene defect

INTRODUCTION

H Syndrome is an autosomal recessive (AR) disease caused by defects in SLCA29A3 gene. This gene encodes the equilibrative nucleoside transporter, the protein which is highly expressed in spleen, lymph node and bone marrow. Autoinflammation and autoimmunity accompanies H Syndrome (HS).

AIM

The aim was to further elucidate the mechanisms of disease by molecular studies in a patient with SLC29A3 gene defect.

PATIENT AND METHODS

Mitochondrial dysfunction, lysosomal integrity, cytokine response in response to stimulation with different pattern recognition receptor ligands, and circulating cell-free mitochondrial-DNA(ccf-mtDNA) level in plasma were analyzed compared to controls to understand the cellular triggers of autoinflammation. RNA sequencing (RS) analyses were also performed in monocytes before/after culture with lipopolysaccharide.

RESULTS

Patient had progressive destructive arthropathy in addition to clinical findings due to combined immunodeficiency. Pure red cell aplasia (PRCA), vitiligo, diabetes, multiple autoantibody positivity, lymphopenia, increased acute phase reactants were present. Recent thymic emigrants (RTE), naïve T cells were decreased, effector memory CD4 + T cells, nonclassical inflammatory monocytes were increased. Patient's peripheral blood mononuclear cells secreted more IL-1β and IL-6, showed lysosomal disruption and significant mitochondrial dysfunction compared to healthy controls. Plasma ccf-mtDNA level was significantly elevated compared to age-matched controls (p < 0.05). RNA sequencing studies revealed decreased expression of NLR Family Caspase Recrument-Domain Containing 4(NLRC4), 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 4(PFKFB4), serine dehydratase(SDS), heparan sulfate(Glucosamine) 3-O-sulfotransferase 1(HS3ST1), neutral cholesterol ester hydrolase 1 (NCEH1), and interleukin-8 (IL-8) in patient's monocytes compared to controls. Longstanding PRCA, which is possibly autoimmune, resolved after initiating monthly intravenous immunoglobulins (IVIG) and low dose steroids to the patient.

CONCLUSION

Although autoinflammation and autoimmunity are reported in HS, by functional analyses we here show in the present patient that over-active inflammasome pathway in HS might be related with mitochondrial and lysosomal dysfunction. Increased plasma ccf-mtDNA may be used as a biomarker of inflammasomopathy in HS. HS should be included in the classification of primary immunodeficiency diseases.

Potential of miRNAs to predict and treat inflammation from the perspective of Familial Mediterranean Fever

AIM

microRNAs (miRNAs) are small noncoding RNAs that play critical roles in physiological networks by regulating host genome expression at the post-transcriptional level. miRNAs are known to be key regulators of various biological processes in different types of immune cells, and they are known to regulate immunological functions. Differential expression of miRNAs has been documented in several diseases, including autoinflammatory and autoimmune diseases. This review aimed to focus on miRNAs and their association with autoimmune and autoinflammatory diseases.

METHODS

All related literature was screened from PubMed, and we discussed the possible role of miRNAs in disease prediction and usage as therapeutic agents from the perspective of Familial Mediterranean Fever (FMF).

CONCLUSIONS

FMF is an inherited autosomal recessive autoinflammatory disease caused by mutations in the MEditerranean FeVer (MEFV) gene, which encodes the protein pyrin. Recent studies have demonstrated that miRNAs may be effective in the pathogenesis of FMF and offer a potential explanation for phenotypic heterogeneity. Further understanding of the role of miRNAs in the pathogenesis of these diseases may help to identify molecular diagnostic markers, which may be important for the differential diagnosis of autoinflammatory diseases. Studies have shown that in the near future, traditional therapies in autoinflammatory diseases may be replaced with novel effective, miRNA-based therapies, such as the delivery of miRNA mimics or antagonists. These approaches may be important for predictive, preventive, and personalized medicine.

Potential role of pyrin, the protein mutated in familial Mediterranean fever, during inflammatory cell migration

Familial Mediterranean fever (FMF), the most common of the systemic autoinflammatory disorders, is caused by mutations in the MEFV (Mediterranean Fever) gene, which encodes the protein pyrin. Neutrophils, one of the major components during inflammation, are the main cell type that expresses pyrin. In response to an inflammatory stimulus, neutrophils migration to their main active site. To date, several pyrin-interacting proteins have been demonstrated to co-localise with the cytoskeletal protein actin, which is important in the process of neutrophil migration and raises the question of whether pyrin plays a role in the actin cytoskeletal network during inflammatory cell migration. In this study, we examined the possible role of pyrin during inflammatory cell migration in neutrophils. We generated a cell migration assay with neutrophils and primary neutrophils from patients. We also knocked down pyrin expression using siRNA and then performed cell migration assay. We showed co-localisation of pyrin and F-actin at the leading edge during inflammatory cell migration. In pyrin knocked down cells, we identified a significant decrease in neutrophil migration. In addition, we demonstrated a dramatic increase in migration in the neutrophils of FMF patients compared with a healthy control group. These data together provide new insight into the cellular function of pyrin and demonstrate an important link between pyrin and polymerising actin in the process of inflammatory cell migration.

Alteration of the microRNA expression profile in familial Mediterranean fever patients

OBJECTIVES

Phenotypic heterogeneity in familial Mediterranean fever (FMF) disease indicated that FMF is not a simple monogenic disease. Therefore it has been suggested that epigenetic factors can be one of the reason for the variations. We undertook this study to test potential involvement of miRNAs in the pathogenesis of FMF.

METHODS

miRNA array was performed on whole blood RNA samples from 6 healthy controls (-/-), 6 FMF patients (M694V/M694V), 6 carriers who displayed the disease phenotype (M694V/-) and 6 healthy carriers (M694V/-). The raw data was analysed by Multi Experiment Viewer (MeV) and candidate miRNAs were determined according to fold change (more than 2.0 or less than -2.0). The validation of differentially expressed miRNAs was done by qRT-PCR. Then we performed pathway analyses with using bioinformatics tools.

RESULTS

14 miRNAs were found to be significant among groups through the analysis with MeV. miR-20a-5p, miR-197-3p, let-7d-3p and miR-574-3p were found to be associated with inflammatory pathway related genes according to DAVID analysis. MiR-20a-5p (FDR: 0,00, FCH: 5.55) was significantly up regulated whereas miR-197-3p (FDR: 0,00, FCH: -2.27) was down regulated in homozygotes patients. Both let-7d-3p (FDR: 0.00, FCH: 28.75) and miR-574-3p (FDR: 0.00, FCH: 3.95) were up regulated in heterozygote patients group.

CONCLUSIONS

We showed that there are several differentially expressed miRNAs both in homozygote and heterozygote FMF patients compared to controls and healthy carriers. Thus we suggest that these miRNAs, related with inflammatory pathways may be responsible for the expression of the disease in FMF.