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1.
Impact of Mon2 monocyte-platelet aggregates on human coronary artery disease.
Brown, RA, Lip, GYH, Varma, C, Shantsila, E
European journal of clinical investigation. 2018;(5):e12911
Abstract
BACKGROUND Monocyte-platelet aggregates (MPAs) form when Mon1, Mon2 or Mon3 monocyte subsets adhere to platelets. They are pathophysiologically linked to coronary artery disease (CAD). However, their individual roles in the occurrence of diffuse CAD remain unknown. MATERIALS AND METHODS Peripheral blood from 50 patients with diffuse CAD, 40 patients with focal CAD and 50 age-matched patients with normal coronary arteries was analysed by flow cytometry to quantify MPAs associated with individual monocyte subsets. Cutaneous forearm microcirculation was assessed using laser Doppler flowmetry at rest and after iontophoresis of acetylcholine (endothelium-dependent vasodilation) and sodium nitroprusside (endothelium-independent vasodilation) at 100 μA for 60 seconds. Patients with CAD had repeat assessment at 6 and 12 months. RESULTS Baseline counts of MPAs with Mon2 subset (CD14++CD16+CC2+ monocytes) were significantly higher in patients with diffuse CAD compared to focal CAD (P = .001) and patients without CAD (P = .006). On multivariate regression, MPAs with Mon2 independently predicted diffuse CAD (odds ratio 1.10, 95% confidence interval 1.02-1.19, P = .01) and correlated negatively with endothelium-dependent microvascular vasodilation (r = -.37, P = .008), an association which persisted after adjustment for covariates. Longitudinal observation confirmed the persistence of an inverse relationship between MPAs with Mon2 and endothelium-dependent microvascular function. CONCLUSION Monocyte-platelet aggregates with Mon2 are increased in patients with diffuse CAD and therefore could represent an important contributor to accelerated coronary atherosclerotic progression by a mechanism involving microvascular endothelial dysfunction.
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DNA Hydroxymethylation Levels Are Altered in Blood Cells From Down Syndrome Persons Enrolled in the MARK-AGE Project.
Ciccarone, F, Valentini, E, Malavolta, M, Zampieri, M, Bacalini, MG, Calabrese, R, Guastafierro, T, Reale, A, Franceschi, C, Capri, M, et al
The journals of gerontology. Series A, Biological sciences and medical sciences. 2018;(6):737-744
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Abstract
Down syndrome (DS) is caused by the presence of part or an entire extra copy of chromosome 21, a phenomenon that can cause a wide spectrum of clinically defined phenotypes of the disease. Most of the clinical signs of DS are typical of the aging process including dysregulation of immune system. Beyond the causative genetic defect, DS persons display epigenetic alterations, particularly aberrant DNA methylation patterns that can contribute to the heterogeneity of the disease. In the present work, we investigated the levels of 5-hydroxymethylcytosine and of the Ten-eleven translocation dioxygenase enzymes, which are involved in DNA demethylation processes and are often deregulated in pathological conditions as well as in aging. Analyses were carried out on peripheral blood mononuclear cells of DS volunteers enrolled in the context of the MARK-AGE study, a large-scale cross-sectional population study with subjects representing the general population in eight European countries. We observed a decrease in 5-hydroxymethylcytosine, TET1, and other components of the DNA methylation/demethylation machinery in DS subjects, indicating that aberrant DNA methylation patterns in DS, which may have consequences on the transcriptional status of immune cells, may be due to a global disturbance of methylation control in DS.
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DNA methylation signatures in peripheral blood mononuclear cells from a lifestyle intervention for women at midlife: a pilot randomized controlled trial.
McEwen, LM, Gatev, EG, Jones, MJ, MacIsaac, JL, McAllister, MM, Goulding, RE, Madden, KM, Dawes, MG, Kobor, MS, Ashe, MC
Applied physiology, nutrition, and metabolism = Physiologie appliquee, nutrition et metabolisme. 2018;(3):233-239
Abstract
Physical activity confers many health benefits, but the underlying mechanisms require further exploration. In this pilot randomized controlled trial we tested the association between longitudinal measures of DNA methylation and changes in objective measures, including physical activity, weight loss, and C-reactive protein levels in community-dwelling women aged 55 to 70 years. We assessed DNA methylation from 20 healthy postmenopausal women, who did not have a mobility disability and allocated them to a group-based intervention, Everyday Activity Supports You, or a control group (monthly group-based health-related education sessions). The original randomized controlled trial was 6 months in duration and consisted of nine 2-h sessions that focused on reducing sedentary behaviour for the intervention group, or six 1-h sessions that focused on other topics for the control group. We collected peripheral blood mononuclear cells, both at baseline and 6 months later. Samples were processed using the Illumina 450k Methylation array to quantify DNA methylation at >485 000 CpG sites in the genome. There were no significant associations between DNA methylation and physical activity, but we did observe alterations at epigenetic modifications that correlated with change in percent body weight over a 6-month period at 12 genomic loci, 2 of which were located near the previously reported weight-associated genes RUNX3 and NAMPT. We also generated a potential epigenetic predictor of weight loss using baseline DNA methylation at 5 CpG sites. These exploratory findings suggest a potential biological link between body weight changes and epigenetic processes.
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Human cellular mitochondrial remodelling is governed by miR-2909 RNomics.
Malik, D, Kaul, D
PloS one. 2018;(9):e0203614
Abstract
BACKGROUND There exists a general recognition of the fact that mitochondrial remodelling as a result of aerobic glycolysis ensures human somatic cells to revert to a more primitive-form exhibiting stem-like phenotype. The present study is an attempt to demonstrate that miR-2909 RNomics within human peripheral blood mononuclear cells (PBMCs) has the inherent capacity to re-program these cells to exhibit mitochondrial remodelling paralleled by aerobic glycolysis together with intracellular lipid inclusions. Such re-programmed PBMCs also expressed genes having ability to sustain their de-differentiation state and survival. MATERIAL AND METHODS Human PBMCs were programed to ectopically express miR-2909. Expression levels of genes including glucose transporter-1 (Glut-1), hexokinase (HK), hypoxia inducia factor-1 (HIF-1α), c-Myc, p53,mechanistic target of rapamycin complex (mTORC1), polycombcomplex protein (Bmi-1), Notch,Nanog,Tie-2, Oct-4,CD59, p53, CD34, B-cell lymphoma-2 (Bcl2),sterol regulatory element-binding protein2 (SREBP2), peroxisome proliferator-activated receptor gamma (PPARγ) nuclear respiratory factor 1 (NRF1), mitochondrial transcription factor A (Tfam), peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) within miR-2909 expression vector transfected human PBMCs as well as PBMCs transfected with control vector containing scrambled sequence after 48h post-transfection using RT-qPCR and cellular ultrastructural features induced by miR-2909 ectopic expression were observed using transmission electron microscopy and morphometric analysis of an electron micrograph. RESULTS Ectopic expression of miR-2909 within human PBMCs resulted in their reprogramming into stem-like phenotype indicated by mitochondrial globular shaped coupled with cristae-poor morphology. Nuclear to cytoplasmic ratio (N/C), quantification of ATP levels, GSSG/GSH ratio, mitochondrial cytochrome c oxidase activity, secreted lactate concentrations, activity of antioxidant enzymes, levels of esterified cholesterol and triglycerides and flow-cytometric detection of apoptosis confirmed the compromised nature of mitochondrial function induced by ectopic miR-2909 expression in human PBMCs. CONCLUSION Based upon these results we propose that AATF gene-encoded miR-2909 may act as an epigenetic switch for cellular aerobic-glycolysis to ensure de-differentiation.
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Familial resemblances in human whole blood transcriptome.
Tremblay, BL, Guénard, F, Lamarche, B, Pérusse, L, Vohl, MC
BMC genomics. 2018;(1):300
Abstract
BACKGROUND Considering the implication of gene expression in the susceptibility of chronic diseases and the familial clustering of chronic diseases, the study of familial resemblances in gene expression levels is then highly relevant. Few studies have considered the contribution of both genetic and common environmental effects to familial resemblances in whole blood gene expression levels. The objective is to quantify the contribution of genetic and common environmental effects in the familial resemblances of whole blood genome-wide gene expression levels. We also make comparisons with familial resemblances in blood leukocytes genome-wide DNA methylation levels in the same cohort in order to further investigate biological mechanisms. RESULTS Maximal heritability, genetic heritability, and common environmental effect were computed for all probes (20.6%, 15.6%, and 5.0% respectively) and for probes showing a significant familial effect (78.1%, 60.1%, and 18.0% respectively). Pairwise phenotypic correlations between gene expression and DNA methylation levels adjusted for blood cell heterogeneity were computed for probes showing significant familial effect. A total of 78 probe pairs among the 7,618,401 possible pairs passed Bonferroni correction (corrected P-value = 6.56 × 10- 9). Significant genetic correlations between gene expression and DNA methylation levels were found for 25 probe pairs (absolute genetic correlation of 0.97). CONCLUSIONS Familial resemblances in gene expression levels were mainly attributable to genetic factors, but common environmental effect also played a role especially in probes showing a significant familial effect. Probes and CpG sites with familial effect seem to be under a strong shared genetic control.
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Changes in peroxisome proliferator-activated receptor alpha target gene expression in peripheral blood mononuclear cells associated with non-alcoholic fatty liver disease.
Li, TT, Tan, TB, Hou, HQ, Zhao, XY
Lipids in health and disease. 2018;(1):256
Abstract
OBJECTIVE To identify differences in the expression of peroxisome proliferator-activated receptor alpha (PPARα) target genes in human peripheral blood mononuclear cells (PBMCs) associated with non-alcoholic fatty liver disease (NAFLD) among Chinese individuals. METHODS Thirty healthy subjects were selected as the control group (CN), and 43 patients newly diagnosed with NAFLD were subdivided into two groups, non-obese group (NF, n = 21) and obese group (OF, n = 22). Expression of PPARα and its target genes was determined in PBMCs. The levels of liver cell damage markers, total cholesterol (TC), triglyceride (TG), free fatty acids (FFA), glucose, and insulin were determined in serum. RESULTS Compared to the CN group, the blood pressure and homeostasis model assessment for insulin resistance (HOMA-IR) were increased in the other groups (P < 0.05), while the systolic blood pressure (SBP) and liver cell damage markers were significantly increased in the OF group (P < 0.05). In the OF group, PPARα target gene expression was 2.03-3.31 times higher than that in the CN group, and a negative correlation was found between PPARα target gene expression and abdominal circumference (AC), body mass index (BMI), diastolic blood pressure (DBP). Additionally, solute carrier family 25 (carnitine/acylcarnitine translocase) member 20 (SLC25A20) and acyl-coenzyme A dehydrogenase 2 long chain (ACADVL) were negatively correlated with HOMA-IR; PPARα, acetyl-coenzyme A dehydrogenase 2 (ACAA2), and carnitine palmitoyltransferase 1A (CPT1A) were positively correlated with HOMA-IR. CONCLUSION There is an up-expression of PPARα target genes in the PBMCs of NAFLD patients, possibly leading to changes in β-oxidation and insulin resistance.
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Quantitation of intracellular triphosphate metabolites of antiretroviral agents in peripheral blood mononuclear cells (PBMCs) and corresponding cell count determinations: review of current methods and challenges.
Xiao, D, Ling, KHJ, Custodio, J, Majeed, SR, Tarnowski, T
Expert opinion on drug metabolism & toxicology. 2018;(8):781-802
Abstract
Peripheral blood mononuclear cells (PBMCs) are a critical component of the immune system and the target cells for human immunodeficiency virus, type 1 (HIV-1) infection. Nucleoside/nucleotide analogs for the treatment of HIV infection are prodrugs that require cellular activation to triphosphate (TP) metabolites for antiviral activity. A reliable method of PBMC isolation and subsequent cell counting, as well as an accurate bioanalytical determination of the TPs in PBMCs are important for understanding the intracellular pharmacokinetic (PK) of the TPs and its correlation with plasma PK, the drug effect, and dose determination. Areas covered: The authors review the challenges and solutions in PBMC sample collection, sample processing, cell lysis, cell counting methods, analyte extraction, and liquid chromatography/tandem mass spectrometry (LC-MS/MS) quantitative analysis of the nucleoside reverse transcriptase inhibitor-triphosphate (NRTI-TP) metabolites, and analogs. Expert opinion: Analyzing large numbers of clinical PBMC samples for determination of NRTI-TPs and analogs in PBMCs requires not only a validated LC-MS/MS bioanalytical method but also reliable methods for PBMC isolation, counting, cell lysis, and analyte recovery, and an approach for assessing analyte stability. Furthermore, a simple, consistent, and validated cell counting method often involves DNA quantitation of the PBMCs samples collected from clinical studies.
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Young adult binge drinkers have immunophenotypic changes in peripheral polymorphonuclear cells and monocytes.
Pérez-García, A, Arroyo-Valerio, AG, Zaldivar-Fujigaki, JL, Bustos-Esquivel, MA, Gastelum-Strozzi, A, Padilla-Castañeda, MA, Reding-Bernal, A, Kershenobich, D, Hernández-Ruiz, J
The American journal of drug and alcohol abuse. 2018;(3):403-412
Abstract
BACKGROUND High alcohol intake on weekends (binge drinking) is more frequent in young adults, who could undergo early liver damage. Alcohol-induced liver damage is characterized by polymorphonuclear cell (PMN) infiltration, which can be represented in the peripheral blood by altered trafficking and activation profiles. OBJECTIVE To evaluate the PMN trafficking and activation immunophenotypic profiles in people with a binge drinking pattern. METHODS People with binge drinking (n = 18, 8 females) or at low risk (n = 16, 13 females) based on their AUDIT and HEPCA scores were studied. Hematic biometry and liver enzyme tests were conducted. Peripheral blood leukocytes were stained for CCR5, CCR4, and CXCR4 (trafficking) and CD69 and CD127 (activation). PMNs and monocytes were analyzed by FACS. The data were analyzed using the T-test and Mann-Whitney's U-test for contrasts and principal component and Fuzzy C means analyses for clustering, with p < 0.05 considered significant. RESULTS Compared to the low-risk group, the binge group showed higher CCR5 expression on PMNs, decreases in the CD69 percentage and positive PMNs per microliter, and decreased CXCR4 expression on monocytes. Six immunophenotypical clusters were identified, all of which were distributed following the CCR5 and CXCR4 main vectors. CONCLUSION Young adult binge drinkers have differential PMN trafficking and activation immunophenotypes, which could be related to the initial onset of alcoholic liver disease and a systemic inflammatory state in response to their alcohol consumption pattern. These findings could lead to the future development of an early diagnostic tool.
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PBMC fixation and processing for Chromium single-cell RNA sequencing.
Chen, J, Cheung, F, Shi, R, Zhou, H, Lu, W, ,
Journal of translational medicine. 2018;(1):198
Abstract
BACKGROUND Interest in single-cell transcriptomic analysis is growing rapidly, especially for profiling rare or heterogeneous populations of cells. In almost all reported works investigators have used live cells, which introduces cell stress during preparation and hinders complex study designs. Recent studies have indicated that cells fixed by denaturing fixative can be used in single-cell sequencing, however they did not usually work with most types of primary cells including immune cells. METHODS The methanol-fixation and new processing method was introduced to preserve human peripheral blood mononuclear cells (PBMCs) for single-cell RNA sequencing (scRNA-Seq) analysis on 10× Chromium platform. RESULTS When methanol fixation protocol was broken up into three steps: fixation, storage and rehydration, we found that PBMC RNA was degraded during rehydration with PBS, not at cell fixation and up to 3-month storage steps. Resuspension but not rehydration in 3× saline sodium citrate (SSC) buffer instead of PBS preserved PBMC RNA integrity and prevented RNA leakage. Diluted SSC buffer did not interfere with full-length cDNA synthesis. The methanol-fixed PBMCs resuspended in 3× SSC were successfully implemented into 10× Chromium standard scRNA-seq workflows with no elevated low quality cells and cell doublets. The fixation process did not alter the single-cell transcriptional profiles and gene expression levels. Major subpopulations classified by marker genes could be identified in fixed PBMCs at a similar proportion as in live PBMCs. This new fixation processing protocol also worked in several other fixed primary cell types and cell lines as in live ones. CONCLUSIONS We expect that the methanol-based cell fixation procedure presented here will allow better and more effective batching schemes for a complex single cell experimental design with primary cells or tissues.
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Statins differentially modulate microRNAs expression in peripheral cells of hyperlipidemic subjects: A pilot study.
Zambrano, T, Hirata, RDC, Hirata, MH, Cerda, Á, Salazar, LA
European journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences. 2018;:55-61
Abstract
AIM: Although statins are considered a cornerstone for the treatment of high cholesterol levels due to their powerful cholesterol-lowering effects, response to drug administration is still one of the main pitfalls of statin treatment. So far, the reasons underlying this undesired outcome are still poorly understood, but recently, various studies have suggested that miRNAs may be involved. Therefore, we aimed at evaluating the effect of short-term low-dose treatment with 2 statins on miRNAs expression in patients with hypercholesterolemia. METHODS A total of 40 hypercholesterolemic (HC) subjects following 1 month of atorvastatin (10 mg/day; n = 20) or simvastatin (10 mg/day; n = 20) were included. Multiple available boinformatic algorithms (TargetScan, miRanda, DianaLab, MicroCosm and PicTar) were employed to select miRNAs regulating genes involved in cholesterol metabolism and statin response. Differential miRNAs expression was determined in peripheral cells using the miScript® miRNA PCR Array platform. Pathways involving differentially expressed miRNAs were explored using the Ingenuity Pathway Analysis software. RESULTS Atorvastatin repressed miR-29a-3p, miR-29b-3p, miR-300, miR-33a-5p, miR-33b-5p and miR-454-3p in HC subjects. On the contrary, simvastatin did not show any effect on miRNAs expression. Network analysis indicated that atorvastatin-modulated miRNAs regulate key cholesterol genes (ABCA1, HMGCR, INSIG1, LDLR, LPL, SCAP and SREBF1). Further subgroups analyses showed that miR-106b-5p, miR-17-3p and miR-590-5p were repressed in HC subjects within the lower quartile of atorvastatin response (lower LDL-C reduction), while the expression of miR-106b-5p, miR-17-3p and miR-183-5p was higher in the upper quartile of simvastatin response (higher LDL-C reduction) (p < 0.05). CONCLUSION We show that a miRNAs-mediated epigenetic mechanism is differentially affected by statins therapy in vivo, which could be implicated in the variable response to these drugs. Further studies are necessary to disclose their particular role in the cholesterol-reduction response to statins.