Genetic Signature of a Healthy Lifestyle: New Horizons for Preventing Noncommunicable Chronic Diseases by Modulating MicroRNA-155.

The development and progression of several noncommunicable diseases (NCDs) are associated with microRNA (miR) 155 (miR-155) activation, which promotes inflammation and oxidative stress. In particular, miR-155 regulates nuclear transcription factor-kappa B (NF-κB) by silencing gene expression of proteins involved in NF-κB suppression, such as suppressor of cytokine signaling 1 (SOCS1) and SH-2 containing inositol 5' polyphosphate 1 (SHIP1), increases the production of reactive oxygen species, and suppresses gene expression of antioxidant enzymes through nuclear factor erythroid 2-related factor 2 (Nrf2) inhibition. In this context, a healthy lifestyle based on a diet rich in nutrients and bioactive compounds as well as regular physical activity may modulate the activity of several miRs. Following this concept, studies involving nutrients, bioactive compounds, and physical activity have been developed to modulate miR-155 activation. This narrative review aims to discuss how a healthy lifestyle based on a diet rich in nutrients, bioactive compounds, and physical activity may modulate the miR-155 pathway and consequently prevent the development and progression of NCDs. Nutrients and bioactive compounds from food may act by inhibiting pathways that promote miR-155 activation such as NF-κB and promote activation of pathways that are associated with the downregulation of miR-155, such as Nrf2, and SOCS1 pathways. Regular physical activity also seems to influence miR-155 levels through an improvement in the immune system during muscle recovery. There is relevant evidence that shows a positive effect of nutrients, bioactive compounds, and physical activity with the modulation of miR-155, which can potentially provide benefits in the clinical setting in cases of NCDs.

The Impact of miR-155-5p on Myotube Differentiation: Elucidating Molecular Targets in Skeletal Muscle Disorders.

MicroRNAs are small regulatory molecules that control gene expression. An emerging property of muscle miRNAs is the cooperative regulation of transcriptional and epitranscriptional events controlling muscle phenotype. miR-155 has been related to muscular dystrophy and muscle cell atrophy. However, the function of miR-155 and its molecular targets in muscular dystrophies remain poorly understood. Through in silico and in vitro approaches, we identify distinct transcriptional profiles induced by miR-155-5p in muscle cells. The treated myotubes changed the expression of 359 genes (166 upregulated and 193 downregulated). We reanalyzed muscle transcriptomic data from dystrophin-deficient patients and detected overlap with gene expression patterns in miR-155-treated myotubes. Our analysis indicated that miR-155 regulates a set of transcripts, including Aldh1l, Nek2, Bub1b, Ramp3, Slc16a4, Plce1, Dync1i1, and Nr1h3. Enrichment analysis demonstrates 20 targets involved in metabolism, cell cycle regulation, muscle cell maintenance, and the immune system. Moreover, digital cytometry confirmed a significant increase in M2 macrophages, indicating miR-155's effects on immune response in dystrophic muscles. We highlight a critical miR-155 associated with disease-related pathways in skeletal muscle disorders.

The simultaneous miR-155-5p overexpression and miR-223-3p inhibition can activate pEMT in oral squamous cell carcinoma

Abstract Objective This study aims to explore the effects of miR-223-3p and miR-155-5p on epithelial-mesenchymal transition (EMT) and migration in oral squamous cell carcinoma (OSCC). Methodology EMT markers (E-cadherin, N-cadherin, P120 catenin (P120ctn), and vimentin) expression was determined by qRT-PCR and western blot analysis in SCC-9 cells which overexpress miR-155-5p and/or not express miR-223-3p. Scratch assays and Transwell migration assays were conducted to evaluate cell migration ability. Results When miR-223-3p was inhibited in OSCC cells, P120ctn and E-cadherin mRNA levels were dramatically downregulated (P<0.05), while N-cadherin levels were significantly upregulated, and the migration ability of OSCC cells increased. The overexpression of miR-155-5p in OSCC cells upregulated miR-223-3p significantly (34-fold) compared to the control group. It also led to significant downregulation of the mRNA of P120ctn and E-cadherin and significant upregulation of the mRNA of N-cadherin and Vimentin (P<0.05). Meanwhile, the migratory ability of OSCC cells significantly increased. When miR-155-5p was overexpressed while miR-223-3p was inhibited, the highest expression of E-cadherin and P120ctn mRNA and the lowest expression of N-cadherin(P<0.05) was observed. Simultaneously, tumor cell migration was significantly facilitated. Conclusion miR-223-3p inhibits the migration of OSCC cells, while miR-155-5p can elevate the miR-223-3p mRNA expression. The simultaneous miR-155-5p overexpression and miR-223-3p inhibition can activate pEMT, increasing OSCC migration in vitro. This provides a novel approach and potential target for the effective treatment of OSCC.

Diagnostic Performance of Serum MicroRNAs for ST-Segment Elevation Myocardial Infarction in the Emergency Department.

Prompt diagnosis of ST-segment elevation myocardial infarction (STEMI) is essential for initiating timely treatment. MicroRNAs have recently emerged as biomarkers in cardiovascular diseases. This study aimed to evaluate the discriminatory capacity of serum microRNAs in identifying an ischemic origin in patients presenting with chest discomfort to the Emergency Department. The study included 98 participants (78 with STEMI and 20 with nonischemic chest discomfort). Significant differences in the expression levels of miR-133b, miR-126, and miR-155 (but not miR-1, miR-208, and miR-208b) were observed between groups. miR-133b and miR-155 exhibited 97% and 93% sensitivity in identifying STEMI patients, respectively. miR-126 demonstrated a specificity of 90% in identifying STEMI patients. No significant associations were found between microRNAs and occurrence of major adverse cardiovascular events (MACE). However, patients with MACE had higher levels of interleukin (IL)-15, IL-21, IFN-γ-induced protein-10, and N-terminal pro B-type natriuretic peptide compared to non-MACE patients. Overall, there were significant associations among the expression levels of microRNAs. However, microRNAs did not demonstrate associations with either inflammatory markers or cardiovascular risk scores. This study highlights the potential of microRNAs, particularly miR-133b and miR-126, as diagnostic biomarkers for distinguishing patients with STEMI from those presenting with nonischemic chest discomfort to the Emergency Department.

Prognostic impact of miR-125b and miR-155b and their relationship with MYC and TP53 in diffuse large B-cell lymphoma: cell-of-origin classification matters.

Tumoral microRNAs, such as miR-125b and miR-155b, are important gene expression regulators with complex pathogenetic mechanisms. However, their role in DLBCL, especially when cell-of-origin classification is considered, are still to be elucidated. In a series of 139 DLBCL cases considering germinal center (GC) versus nonGC subtypes, we investigated miR-125b and miR-155b expression by in situ hibridization and their association with some immunophenotypic presentations, including MYC, BCL2 and TP53 expression, MYC, BCL2 and BCL6 translocation status, as well as clinicopathological features and outcomes. miR-125b detection was positively correlated to the Ki-67 index (P = 0.035) in the nGC. Considering the GC subgroup, the percentage of miR-125b positive cells was also correlated to either MYC and MYC/BCL2 double expression (P = 0.047 and P = 0.049, respectively). When it comes to nGC patients, miR-155b percentage and intensity, as well as Allred score, were positively correlated to disease progression (P = 0.038, P = 0.057 and P = 0.039, respectively). In a multivariate analysis, GC phenotype was a significant independent factor associated with higher OS (P = 0.007) and, considering the nGC group, although not significant, the expression of TP53, miR-125b and miR-155b seems to be potential prognostic biomarkers in these tumors. This study demonstrated different pathways based on cell-of-origin classification and highlighted different clinical outcomes. miR-125b, miR-155b and TP53 expression may also represent potential prognostic factors in nGC-DLBCL.

SOD1G93A Astrocyte-Derived Extracellular Vesicles Induce Motor Neuron Death by a miRNA-155-5p-Mediated Mechanism.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by upper and lower motor neuron (MN) degeneration. Astrocytes surrounding MNs are known to modulate ALS progression. When cocultured with astrocytes overexpressing the ALS-linked mutant Cu/Zn superoxide dismutase (SOD1G93A) or when cultured with conditioned medium from SOD1G93A astrocytes, MN survival is reduced. The exact mechanism of this neurotoxic effect is unknown. Astrocytes secrete extracellular vesicles (EVs) that transport protein, mRNA, and microRNA species from one cell to another. The size and protein markers characteristic of exosomes were observed in the EVs obtained from cultured astrocytes, indicating their abundance in exosomes. Here, we analyzed the microRNA content of the exosomes derived from SOD1G93A astrocytes and evaluated their role in MN survival. Purified MNs exposed to SOD1G93A astrocyte-derived exosomes showed reduced survival and neurite length compared to those exposed to exosomes derived from non-transgenic (non-Tg) astrocytes. Analysis of the miRNA content of the exosomes revealed that miR-155-5p and miR-582-3p are differentially expressed in SOD1G93A exosomes compared with exosomes from non-Tg astrocytes. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicates that miR-155-5p and miR-582-3p predicted targets are enriched in the neurotrophin signaling pathway. Importantly, when levels of miR-155-5p were reduced by incubation with a specific antagomir, SOD1G93A exosomes did not affect MN survival or neurite length. These results demonstrate that SOD1G93A-derived exosomes are sufficient to induce MN death, and miRNA-155-5p contributes to this effect. miRNA-155-5p may offer a new therapeutic target to modulate disease progression in ALS.

miR-155 exerts posttranscriptional control of autoimmune regulator (Aire) and tissue-restricted antigen genes in medullary thymic epithelial cells.

BACKGROUND: The autoimmune regulator (Aire) gene is critical for the appropriate establishment of central immune tolerance. As one of the main controllers of promiscuous gene expression in the thymus, Aire promotes the expression of thousands of downstream tissue-restricted antigen (TRA) genes, cell adhesion genes and transcription factor genes in medullary thymic epithelial cells (mTECs). Despite the increasing knowledge about the role of Aire as an upstream transcriptional controller, little is known about the mechanisms by which this gene could be regulated. RESULTS: Here, we assessed the posttranscriptional control of Aire by miRNAs. The in silico miRNA-mRNA interaction analysis predicted thermodynamically stable hybridization between the 3'UTR of Aire mRNA and miR-155, which was confirmed to occur within the cellular milieu through a luciferase reporter assay. This finding enabled us to hypothesize that miR-155 might play a role as an intracellular posttranscriptional regulator of Aire mRNA. To test this hypothesis, we transfected a murine mTEC cell line with a miR-155 mimic in vitro, which reduced the mRNA and protein levels of Aire. Moreover, large-scale transcriptome analysis showed the modulation of 311 downstream mRNAs, which included 58 TRA mRNAs. Moreover, miR-155 mimic-transfected cells exhibited a decrease in their chemotaxis property compared with control thymocytes. CONCLUSION: Overall, the results indicate that miR-155 may posttranscriptionally control Aire mRNA, reducing the respective Aire protein levels; consequently, the levels of mRNAs encode tissue-restricted antigens were affected. In addition, miR-155 regulated a crucial process by which mTECs allow thymocytes' migration through chemotaxis.

Paracetamol poisoning induces acute liver injury in rats: inhibition of miR-155/cd45 axis-mediated antioxidant depletion and hepatotoxicity using quercetin and resveratrol / La intoxicación por paracetamol induce daño hepático agudo en ratas: inhibición de la depleción de antioxidantes mediado por el eje miR-155/cd45 y hepatotoxicidad usando quercetina y resveratrol

SUMMARY: Ingestion of an overdose of paracetamol (also called acetaminophen, or APAP) induces hepatotoxicity that can lead to liver failure. The link between the pro-inflammatory microRNA-155 (miR-155) and leukocyte infiltration (CD45) in APAP- antioxidant depletion and liver toxicity with and without the natural polyphenolic compounds, quercetin (QUR) plus resveratrol (RES) has not been previously studied. Therefore, acute hepatic injury was induced in rats by 2 g/kg APAP (single dose, orally) and another group started QUR (50 mg/kg) plus RES (30 mg/kg) treatment one week prior to APAP ingestion. Animals were culled 24 hours post the paracetamol treatment. APAP overdose induced hepatic and blood levels of miR-155 expression, CD45 (leukocyte common antigen) immunostaining, degenerated hepatocytes, and hepatic injury enzymes; alanine aminotransferase (ALT) and aspartate aminotransferase (AST), which were markedly decreased by QUR+RES. Whereas, APAP intoxication ameliorated liver tissue levels of the antioxidants, glutathione peroxidase and superoxide dismutase that were augmented by QUR+RES. Moreover, a significant (p<0.05) correlation between miR-155/CD45 axis and liver tissue injury was observed. These findings show that paracetamol intoxication augments miR- 155/CD45 axis-mediated modulation of antioxidants and liver injury in rats, and is protected by QUR+RES.

RESUMEN: La ingestión de una sobredosis de paracetamol (también llamado acetaminofeno o APAP) induce hepatotoxicidad que puede provocar insuficiencia hepática. El vínculo entre el microARN-155 proinflamatorio (miR-155) y la infiltración de leucocitos (CD45) en el agotamiento de APAP- antioxidante y la toxicidad hepática con y sin los compuestos polifenólicos naturales, quercetina (QUR) más resveratrol (RES) no ha sido previamente investigado. En este estudio, se indujo daño hepático agudo en ratas con 2 g/kg de APAP (dosis única, por vía oral) y otro grupo comenzó el tratamiento con QUR (50 mg/ kg) más RES (30 mg/kg) una semana antes de la ingestión de APAP. Los animales se sacrificaron 24 horas después del tratamiento con paracetamol. La sobredosis de APAP indujo niveles hepáticos y sanguíneos de expresión de miR-155, inmunotinción de CD45 (antígeno leucocitario común), degeneración de los hepatocitos y daño hepático enzimático; alanina aminotransferasa (ALT) y aspartato aminotransferasa (AST), disminuyeron notablemente con QUR+RES. Mientras que la intoxicación con APAP mejoró los niveles de antioxidantes, glutatión peroxidasa y superóxido dismutasa en el tejido hepático los que aumentaron con QUR+RES. Además, se observó una correlación significativa (p<0,05) entre el eje miR-155/CD45 y la lesión del tejido hepático. Estos hallazgos muestran que la intoxicación por paracetamol aumenta la modulación mediada por el eje miR-155/CD45 de los antioxidantes y la lesión hepática en ratas, y está protegida por QUR+RES.

Extracellular vesicles and their associated miRNAs as potential prognostic biomarkers in chronic lymphocytic leukemia.

PURPOSE OF REVIEW: Many prognostic and predictive biomarkers have been proposed for chronic lymphocytic leukaemia (CLL). Here, we aim to discuss the evidence showing a prognostic potential for extracellular vesicles (EV) and their associated microRNAs (miRNAs). RECENT FINDINGS: EV are produced by several cells in the body as a physiological event; however, there is evidence suggesting that an elevated EV concentration is present in the circulation of CLL patients. Moreover, some studies have associated EV concentration with advanced Rai stage and unmutated CLL while others have demonstrated its potential as an independent prognostic factor for TTFT and OS. Finally, some studies have shown that CLL EV shared some dysregulated microRNAs with CLL cells and plasma. On the other hand, it was found that CLL EV has a distinctive microRNA expression profile. Until now, EV-associated miR-155 is the most studied miRNA. Despite methodological diversity and limitations in study design, unanimity in CLL EV concentration behaviour and miRNA content has been found.

Peripheral Blood miRome Identified miR-155 as Potential Biomarker of MetS and Cardiometabolic Risk in Obese Patients.

This study explored circulating miRNAs and target genes associated with metabolic syndrome (MetS) and cardiometabolic risk in obese patients. Small-RNA sequencing was used to assess the peripheral blood miRNome of 12 obese subjects (6 MetS and 6 non-MetS). Differentially expressed miRNAs and target genes were further analyzed by qPCR in a larger sample of obese patients (48 MetS and 32 non-MetS). miRNA:mRNA interactions were studied using in silico tools. miRNome analysis identified 10 downregulated miRNAs in MetS compared to non-Met patients (p < 0.05). In silico studies revealed three miRNAs (miR-155, miR-181a, and let-7a) and their predictive targets (CCAAT/enhancer-binding protein beta-CEBPB, KRAS proto-oncogene, GTPase-KRAS and suppressor of cytokine signaling 1-SOCS1) with a potential role in the insulin receptor signaling pathway. miR-155 expression was reduced and CEBPB mRNA levels were increased in MetS patients (p < 0.05), and these effects were correlated with the number of MetS diagnostic criteria (p < 0.05). Increased HOMA-IR (>7.6) was associated with low miR-155 levels, high CEBPB expression, and serum hsCRP (p < 0.05). miR-155 was negatively correlated with CEBPB, HOMA-IR, and plasma fibrinogen, and positively correlated with serum adiponectin (p < 0.05). Downregulation of circulating miR-155 is associated with insulin resistance, poor glycemic control, and increased MetS-related cardiometabolic risk, and these effects are potentially mediated by interaction with CEBPB.

Chronic exposure to ethanol alters the expression of miR-155, miR-122 and miR-217 in alcoholic liver disease in an adult zebrafish model.

AIM: The aim of this study was to evaluate the hepatic and circulating expression of miR-155, miR-122 and miR-217 in a model of chronic exposure to ethanol in adult zebrafish. METHODS: Wild-type adult zebrafish were divided into two groups (n = 281): an EG (exposed to 0.5% v/v Ethanol in aquarium water) and a CG (without ethanol). After 28 days the animals were euthanized, followed by histopathological analysis, quantification of lipids, triglycerides and inflammatory cytokines in liver tissue. miR-155, miR-122 and miR-217 gene expression was quantified in liver tissue and serum. RESULTS: We observed hepatic lesions and increased accumulation of hepatic lipids in the EG. The expression of il-1ß was higher in the EG, but there were no differences in il-10 and tnf-α between groups. In the liver, expression of miR-122 and miR-155 was higher in the EG. The circulating expression of miR-155 and miR-217 was significantly higher in the EG. CONCLUSION: Chronic exposure to ethanol in zebrafish leads to altered hepatic and circulating expression of miR-155, miR-122 and miR-217. This confirms its potential as a biomarker and therapeutic target.

Lead (Pb) exposure is associated with changes in the expression levels of circulating miRNAS (miR-155, miR-126) in Mexican women.

The environmental contamination with lead (Pb) is considered a critical issue worldwide. Therefore, this study aimed to evaluate the expression levels of circulating miRNAs (miR-155, miR-126, and miR-145) in Mexican women exposed to Pb. Blood lead levels (BLL) were assessed in enrolled women (n = 190) using an atomic absorption method. Also, serum miRNAs expression levels were quantified through a real-time PCR assay. A mean BLL of 10.5 ± 4.50 µg/dL was detected. Overexpression of miR-155 was detected in highly exposed women. Besides, a significant simple positive relationship (p < 0.05) was found between BLL and serum miR-155 expression levels. Additionally, a significant inverse correlation (p < 0.05) was determined between BLL and serum miR-126 expression levels, as downregulation of miR-126 expression levels was observed in highly exposed women. The findings in this study are the concern, as epigenetic changes detected may represent a connection between health illnesses and Pb exposure.

Long noncoding RNA LINC01189 is associated with HCV-hepatocellular carcinoma and regulates cancer cell proliferation and chemoresistance through hsa-miR-155-5p.

INTRODUCTION AND OBJECTIVES: Emerging evidence has demonstrated that long noncoding RNAs (lncRNAs) may be closely associated with Hepatitis C virus (HCV) infection and the development of hepatocellular carcinoma (HCC). In this study, we investigated the expression and functions of a lncRNA, LINC01189, in HCV-associated HCC. PATIENTS OR MATERIALS AND METHODS: LINC01189 expression was measured in HCC tumors, HCV-infected HCC tumors and HCV-infected HCC cells. LINC01189 was overexpressed in HCV-infected HepG2 cells to measure its function on HCV-correlated cancer proliferation. In HCC cell lines of Huh7 and Hep3B, LINC01189 was upregulated to investigate its effects on cancer cell proliferation and 5-FU chemoresistance. The competing endogenous RNA (ceRNA) target of LINC01189, human microRNA-155-5p (hsa-miR-155-5p) was probed by dual-luciferase assay and qRT-PCR. Hsa-miR-155-5p was upregulated in LINC01189-overexpessed Huh7 and Hep3B cells to investigate their epigenetic correlation on HCC development regulation. RESULTS: LINC01189 is downregulated in HCV-infected HCC tumors and cell lines. LINC01189 overexpression inhibited HCC cancer cell proliferation and 5-FU chemoresistance. Hsa-miR-155-5p was confirmed to be a ceRNA target of LINC01189 in HCC. Upregulating hsa-miR-155-5p reversed the LINC01189-mediated inhibition on HCC proliferation and 5-FU chemoresistance. CONCLUSIONS: LINC01189 downregulation is associated with HCV infection in HCC, and it has tumor-suppressing effects on HCC development through hsa-miR-155-5p.

Gene polymorphism and plasma levels of miR-155 in diabetic retinopathy.

Circulating microRNA-155 (miR-155) is associated with type 2 diabetes mellitus (T2DM) and the rs767649 polymorphism in the pre-MIR155 gene is associated with miR-155 expression. However, their relationship with diabetic retinopathy (DR) is still unknown. Therefore, the aim of this case-control study was to test the hypothesis that the rs767649 polymorphism in the pre-MIR155 gene is associated with DR in South Brazilians with T2DM. We also evaluated the association of plasma levels of miR-155 with DR and the rs767649 polymorphism in a subgroup of subjects. The rs767649 polymorphism was genotyped in 139 blood donors and 546 T2DM patients (244 had no DR, 161 had non-proliferative DR and 141 had proliferative DR). miR-155 expression was quantified in 20 blood donors and 60 T2DM patients (20 from each group). Among T2DM patients, the carriership of the A allele and the A allele were more frequent in subjects with DR than in those without it (P < 0.05), and the A allele was independently associated with an increased risk of DR (adjusted OR = 2.12, 95% CI = 1.12-4.01). The plasma levels of miR-155 were lower in T2DM patients than in blood donors (P < 0.001). However, the miR-155 levels did not differ according to the presence and severity of DR or according to rs767649 genotypes among T2DM patients. These findings support that the rs767649 polymorphism in the pre-MIR155 gene is associated with DR in T2DM and that the miR-155 plasma levels might be associated with T2DM. Additional studies are needed to further investigate their clinical significance in DR and T2DM.

Increased levels of adipose tissue-resident Th17 cells in obesity associated with miR-326.

miRNAs are important immune regulators in the control of the CD4 + T cells phenotype. miR-326 regulates the differentiation towards Th17 cells and the inhibition of miR-155 is associated with low levels of Treg cells. However, miRNAs expression and transcription factors associated with these lymphocyte subsets in obesity-induced adipose tissue inflammation is still unknown. The aim of this work was to identify Th17 cells in subcutaneous adipose tissue (SAT), proinflammatory cytokine production and their association with the miRNAs and transcription factors involved. We collected SAT samples obtained by lipoaspiration from individuals with normal weight, overweight and obesity. We obtained the stromal vascular fractions and then a Ficoll gradient was performed to obtain adipose tissue mononuclear cells (ATMC). Th17 cells were evaluated by flow cytometry and the expression of miR-326, miR-155, RORC2 and FOXP3 by qRT-PCR. We also analyzed cytokines from the supernatants of the ATMC culture and measured the FOXP3 methylation percentage by bisulfite conversion by PCR. According to the results, the frequency of Th17 cells and RORC2 expression was higher in individuals with obesity and associated with miR-326 expression. The ATMC from this group secreted a proinflammatory cytokine profile by in vitro assay. In contrast, lower levels of mRNA FOXP3 expression was detected in ATMC from individuals with obesity that correlated with methylation percentage of FOXP3 gene but no association with miR-155 was detected. Our results suggested that miR-326 participates in the polarization towards Th17 promoting the inflammatory state in the obesity-induced adipose tissue.

Pegylated interferon-α inhibits the proliferation of hepatocellular carcinoma cells by downregulating miR-155.

INTRODUCTION AND AIMS: Interferon-α (IFN) has shown potential benefits in patients with hepatocellular carcinoma (HCC), and these effects may be mediated by inhibiting cancer cell proliferation. However, the detailed mechanisms underlying the anti-proliferative effects of IFN remain obscure. In this study, we evaluate the role of the novel oncogenic microRNA (miRNA) miR-155 in the anti-proliferative effects of pegylated interferon-α (PEG-IFN) on HCC cells. METHODS: The effects of PEG-IFN on HepG2 cell proliferation, migration and invasion were determined using the MTT assay, flow cytometry analysis and the Transwell assay, respectively. Reverse transcription quantitative polymerase chain reaction was used to analyze miR-155 expression. The levels of proteins involved in Wnt/ß-catenin signal transduction were determined by western blot analysis and immunofluorescence staining. Mimics of miR-155 were transfected into HepG2 cells to assess the role of miR-155 in the PEG-IFN-induced anti-proliferative effect. RESULTS: PEG-IFN significantly inhibited the proliferation, migration and invasion of HepG2 cells in a dose-dependent manner by inhibiting cell cycle progression. In parallel with reduced cell proliferation, migration and invasion, miR-155 was efficiently downregulated by PEG-IFN in a dose-dependent manner. Moreover, the transfection of miR-155 decreased the inhibitory effect of PEG-IFN on HepG2cell proliferation, migration and invasion, as well as the downregulation of proteins in the Wnt/ß-catenin pathway. CONCLUSIONS: The anti-proliferative effects of PEG-IFN on HCC are at least partially attributable to the downregulation of miR-155.

Circulating miRNA-126, -145 and -155 levels in Mexican women exposed to inorganic arsenic via drinking water.

The aim of this research was to investigate circulating expression levels of three miRNAs (miR-126, miR-155, and miR-145) proposed as predictive CVD biomarkers in Mexican women exposed to inorganic arsenic via drinking water. Mean UAs concentration of 19.5 ± 14.0 µg/g creatinine was found after urine samples were analyzed (n = 105). Significant associations between UAs levels and serum expression levels of miR-155 (p < 0.05) and miR-126 (p < 0.05) were observed after adjustment for assessed co-variables. Alterations in the serum expression levels of miR-155 and miR-126 may be associated with the onset and development of cardiovascular diseases, hence miRNAs could be proposed as prognostic CVD biomarkers. Data found in this study are of concern and risk reduction plans are necessary for the assessed communities to prevent cardiovascular events in this population of women.

Expression levels of circulating microRNAs-126, -155, and -145 in Mexican women exposed to polycyclic aromatic hydrocarbons through biomass fuel use.

Human exposure to polycyclic aromatic hydrocarbons (PAHs) has been considered a risk determinant for the development of cardiovascular diseases (CVD). Therefore, the aim of this study was to assess expression levels of vascular-related miRNAs, miR-126, miR-155, and miR-145, in plasma from women (aged 19-81 years) exposed (n = 100) and non-exposed (n = 20) to PAHs via biomass combustion smoke.1-hydroxypyrene (1-OHP) was determined in urine as a biomarker of exposure to PAHs using high-resolution liquid chromatography. Plasma expression levels of proposed miRNAs were determined by quantitative real-time PCR. Additionally, traditional risk factors (age, blood pressure, serum lipid profile, blood glucose, and among others) associated with CVD were evaluated. Urinary 1-OHP concentrations and plasma expression levels of miR-126 and miR-155 were significantly higher (P < 0.05) in women using wood as a fuel source in their homes (indoor) compared to women from the reference group (non-exposed to biomass smoke). Besides, multivariate linear regression analyses revealed that miR-126[ß = 0.61; 95% confidence interval (0.32-0.90)] and miR-155 [ß = 0.45; 95% confidence interval (0.13-0.84)] expression levels were significantly associated with urinary 1-OHP concentrations after being adjusted by traditional risk factors (P < 0.05). In contrast, no significant relationship was found between miR-145 and urinary 1-OHP levels. Furthermore, miRNAs assessed in this investigation are associated with CVD events. Consequently, actions to reduce exposure to PAHs in the evaluated population are warranted. Environ. Mol. Mutagen. 60:546-558, 2019. © 2019 Wiley Periodicals, Inc.

Exposure to biomass smoke is associated with an increased expression of circulating miRNA-126 and miRNA-155 in Mexican women: a pilot study.

Household air pollution has been associated as a risk factor for cardiovascular diseases (CVD). Therefore, the aim of this study was to assess the expression of vascular inflammation regulators miR-126 and miR-155 in plasma from women that cook with wood and women that cook with liquid petroleum gas (LPG). A cumulative index of exposure to smoke (CIES) was estimated, urinary 1-hydroxypyrene (1-OHP) levels were quantified and miRNAs expression levels were determined by quantitative real-time PCR (qRT-PCR). Biochemical clinical parameters were also evaluated. The average values for CIES and 1-OHP were 140 ± 86.8 hours-years (12.0-270 hours-years) and 0.52 ± 0.45 µmol/mol creatinine, respectively. miR-126 and miR-155 expression levels were significantly higher (p < 0.01) in the wood users compared to LPG users. Besides, we found a significant association (p < 0.01) between miR-126 and miR-155 expression levels and CIES and urinary 1-OHP concentrations. These results contribute to the current evidence about the cardiovascular risk related to biomass smoke exposure, from an epigenetic level.

Evaluation of epigenetic alterations (mir-126 and mir-155 expression levels) in Mexican children exposed to inorganic arsenic via drinking water.

Recently, a great number of epidemiological studies have shown evidence that exposure to inorganic arsenic could have harmful effects on the cardiovascular system of humans. However, the underlying mechanisms through which arsenic induces cardiovascular toxic effects remain unclear. In this regard, epigenetic mechanisms have emerged as a probable connection between environment and disease phenotypes, including cardiovascular diseases. Therefore, this study aimed to evaluate epigenetic changes related to cardiotoxicity (miR-126 and miR-155 expression levels) in children from San Luis Potosi, Mexico exposed to inorganic arsenic. From 2014 to 2015, in a cross-sectional study, children (aged 6-12 years; n = 73) attending public schools at the studied sites were enrolled to take part in this study. Urinary arsenic was used as an exposure biomarker and analyzed by an atomic absorption spectrophotometry technique. On the other hand, miR-126 and miR-155 expression levels were evaluated by qRT-PCR. A mean urinary arsenic level of 30.5 ± 25.5 µg/g of creatinine was found. Moreover, the data showed a significant negative association (p < 0.05) between urinary arsenic concentrations and plasma miR-126 levels. However, an association between urinary arsenic concentrations and plasma miR-155 levels was not found (p > 0.05). In this regard, some investigations have shown an association between diminished plasma miR-126 levels and cardiovascular illnesses. The results found in this study are of concern. However, more similar studies including a larger sample size are necessary in order to clarify the real significance of the data.