Epigenetic Modification in Coronary Atherosclerosis

Coronary artery disease (CAD) and its major complication, acute myocardial infarction (AMI), are the leading causes of disability and death worldwide. An individual's risk of developing CAD and MI is modulated by an interplay between genetic and lifestyle factors. It is now clear that epigenetics may play a central role in the development of CAD because epigenetic patterns are affected by the environment and can modulate gene expression. Here, the authors discuss the major epigenetic changes that contribute to CAD and the latest discoveries on the influence of the environment on epigenetic profiles in the development of CAD

Lox-1 and its splice variants: a new challenge for atherosclerosis and cancer-targeted therapies

Alternative splicing (AS) is a process in which precursor messenger RNA (pre-mRNA) splicing sites are differentially selected to diversify the protein isoform population. Changes in AS patterns have an essential role in normal development, differentiation and response to physiological stimuli. It is documented that AS can generate both "risk" and "protective" splice variants that can contribute to the pathogenesis of several diseases including atherosclerosis. The main endothelial receptor for oxidized low-density lipoprotein (ox-LDLs) is LOX-1 receptor protein encoded by the OLR1 gene. When OLR1 undergoes AS events, it generates three variants: OLR1, OLR1D4 and LOXIN. The latter lacks exon 5 and two-thirds of the functional domain. Literature data demonstrate a protective role of LOXIN in pathologies correlated with LOX-1 overexpression such as atherosclerosis and tumors. In this review, we summarize recent developments in understanding of OLR1 AS while also highlighting data warranting further investigation of this process as a novel therapeutic target

Characterisation of nickel(II) extraction by 2-hydroxy-5-nonylacetophenone oxime (LIX 84) in a micellar phase

The properties of the nickel(II)/2-hydroxy-5-nonylacetophenone oxime (HNAPO), an active ingredient in LIX 84, extraction system were characterised in a micellar system. The extinction coefficient, &lambda;max of HNAPO (316 nm) and the Ni2+ complex (387 nm) in a neutral micellar system, poly dispersed octa-ethyleneglycol mono-n-dodecyl ether (G12A8) were determined as 3100 and 3500 M&minus;1 cm&minus;1, respectively. HNAPO was found to have a neutral micellar phase and bulk aqueous phase pKa of 11.5 and 12.5, respectively. The extraction equilibrium constant, Kex, was determined to be 10&minus;8.0, and the deviation from theory observed at high pH can be accounted for by consideration of the competition for nickel(II) ions by hydroxide ions and HNAPO. A micellar phase of octa-ethyleneglycol mono-n-dodecyl ether (C12E8) was determined to be an appropriate model of the free oil/water interface from the solubilised location of HNAPO. Utilising the interfacial probe, 4-heptadecyl-7-hydroxy coumarin (HHC) allowed the determination of the electrostatic surface potential of mixed micelles of G12A8 and sodium dodecyl sulphate (SDS) or dodecyl trimethyl ammonium chloride (DTAC). The electrostatic surface potential was a linear function of the number of additional surfactant monomers within the G12A8 micelle, for the concentration range studied. For G12A8/DTAC mixed micelles, the surface potential was given by +1.1 mV per DTAC molecule per micelle, and for G12A8/SDS mixed micelles the relationship was &minus;1.4 mV per SDS molecule per micelle.<br /

The human rs1050286 polymorphism alters LOX-1 expression through modifying miR-24 binding

The up-regulation of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), encoded by the OLR1 gene, plays a fundamental role in the pathogenesis of atherosclerosis. Moreover, OLR1 polymorphisms were associated with increased susceptibility to acute myocardial infarction (AMI) and coronary artery diseases (CAD). In these pathologies, the identification of therapeutic approaches that can inhibit or reduce LOX-1 overexpression is crucial. Predictive analysis showed a putative hsa-miR-24 binding site in the 3′UTR of OLR1, ‘naturally’ mutated by the presence of the rs1050286 single nucleotide polymorphism (SNP). Luciferase assays revealed that miR-24 targets OLR1 3′UTR-G, but not 3′UTR-A (P < 0.0005). The functional relevance of miR-24 in regulating the expression of OLR1 was established by overexpressing miR-24 in human cell lines heterozygous (A/G, HeLa) and homozygous (A/A, HepG2) for rs1050286 SNP. Accordingly, HeLa (A/G), but not HepG2 (A/A), showed a significant down-regulation of OLR1 both at RNA and protein level. Our results indicate that rs1050286 SNP significantly affects miR-24 binding affinity to the 3′UTR of OLR1, causing a more efficient post-transcriptional gene repression in the presence of the G allele. On this basis, we considered that OLR1 rs1050286 SNP may contribute to modify OLR1 susceptibility to AMI and CAD, so ORL1 SNPs screening could help to stratify patients risk

OLR1 and Loxin Expression in PBMCs of Women with a History of Unexplained Recurrent Miscarriage: A Pilot Study

The aim of this study was to evaluate the expression of OLR1 and its alternative splicing isoform Loxin in unexplained recurrent miscarriage (uRM)

Low molecular weight heparin -induced miRNA changes in peripheral blood mononuclear cells in pregnancies with unexplained recurrent pregnancy loss

: Unexplained recurrent pregnancy loss (uRPL) is a clinical condition for which there is a lack of evidenced-based therapies. However, in clinical practice, low molecular weight heparin (LMWH) has been widely used as an empirical therapy since immune effects have been hypothesized in modulating immune tolerance at the fetal-maternal interface. Epigenetic mechanisms are involved in establishing of immune tolerance, at fetal-maternal interface. To investigate potential induced immune-epigenetic changes at maternal periphery level, which could reflect the maternal-fetal interface condition, seems to open up new therapeutical strategies, since microRNAs circulating in maternal plasma and in peripheral blood mononuclear cells (PBMCs) may be specific and sensitive immunological markers/predictors of adverse pregnancy outcomes such as RPL. Our aim in this pilot study is to evaluate potential LMWH effects on genes regulating immunological response key mechanisms related to maternal-fetal tolerance processes, by studying circulating miRNAs in maternal peripheral blood. We tested a panel of selected miRNAs on three groups: 18 healthy pregnant women, 20 pregnant women affected by uRPL, 18 pregnant women affected by uRPL, treated with LMWH. The majority of differentially expressed miRNAs (miR 374a-5p, 19a-3p, 30e-5p, 128-3p, 155-5p and 200c-3p) were found to be modulated by LMWH, which seems to have a positive function in RPL patients, by bringing patients' values back to those comparable to the control ones. Selected microRNA panels would appear to be an effective clinical tool for uRPL diagnosis and management. LMWH-modified miRNA expression levels could be targets for immunotherapy, as LMWH would appear to restore physiological miRNA levels, which are dysregulated in uRPL

MiR-423 is differentially expressed in patients with stable and unstable coronary artery disease: A pilot study

Coronary artery disease (CAD) and acute myocardial infarction (AMI) are the leading causes of death worldwide. Since only a subset of CAD patients develops myocardial infarction, it is likely that unique factors predispose to AMI. Circulating microRNAs represent diagnostic powerful biomarkers for detection of heart injuries and patients' risk stratification. Using an array-based approach, the expression of 84 circulating miRNAs was analyzed in plasma of pooled stable CAD patients (CAD; n = 5) and unstable CAD patients (AMI_T0; n = 5) enrolled within 24 hours from an AMI event. The array experiments showed 27 miRNAs differentially expressed with a two-fold up- or down-regulation (10 up- and 17 down-regulated miRNAs). Among them, miR-423-5p dis-regulation was confirmed in a larger case study (n = 99). Circulating miR-423-5p resulted to be significantly down-regulated within 24 hours from the AMI event (FC = -2, p≤0.05). Interestingly, miR-423-5p expression resulted to be increased (FC = +2; p≤0.005) in a subgroup of the same AMI patients (AMI_T1; n = 11) analyzed after 6 months from the acute event. We extended miR-423-5p expression study on PBMCs (peripheral blood mononuclear cells), confirming also in this tissue its up-regulation at 6 months post-AMI. Receiver operating characteristic analyses (ROC) were performed to detect the power of miR-423-5p to discriminate stable and unstable CAD. In plasma, miR-423-5p expression accurately distinguishes stable and unstable CAD patients (AUC = 0.7143, p≤0.005). Interestingly, the highest discriminatory value (AUC = 0.8529 p≤0.0005) was identified in blood cells, where miR-423-5p expression is able to differentiate unstable CAD patients during an acute event (AMI_T0) from those at six months post-AMI (AMI_T1). Furthermore, cellular miR-423-5p may discriminate also stable CAD patients from unstable CAD patients after six months post-AMI (AUC = 0.7355 p≤0.05). The results of this pilot-study suggest that miR-423-5p expression level both in plasma and blood cells, could represent a new promising biomarker for risk stratification of CAD patients

Low molecular weight heparin -induced miRNA changes in peripheral blood mononuclear cells in pregnancies with unexplained recurrent pregnancy loss

Unexplained recurrent pregnancy loss (uRPL) is a clinical condition for which there is a lack of evidenced-based therapies. However, in clinical practice, low molecular weight heparin (LMWH) has been widely used as an empirical therapy since immune effects have been hypothesized in modulating immune tolerance at the fetal-maternal interface. Epigenetic mechanisms are involved in establishing of immune tolerance, at fetal-maternal interface. To investigate potential induced immune-epigenetic changes at maternal periphery level, which could reflect the maternal-fetal interface condition, seems to open up new therapeutical strategies, since microRNAs circulating in maternal plasma and in peripheral blood mononuclear cells (PBMCs) may be specific and sensitive immunological markers/predictors of adverse pregnancy outcomes such as RPL. Our aim in this pilot study is to evaluate potential LMWH effects on genes regulating immunological response key mechanisms related to maternal-fetal tolerance processes, by studying circulating miRNAs in maternal peripheral blood. We tested a panel of selected miRNAs on three groups: 18 healthy pregnant women, 20 pregnant women affected by uRPL, 18 pregnant women affected by uRPL, treated with LMWH. The majority of differentially expressed miRNAs (miR 374a-5p, 19a-3p, 30e-5p, 128–3p, 155–5p and 200c-3p) were found to be modulated by LMWH, which seems to have a positive function in RPL patients, by bringing patients' values back to those comparable to the control ones. Selected microRNA panels would appear to be an effective clinical tool for uRPL diagnosis and management. LMWH-modified miRNA expression levels could be targets for immunotherapy, as LMWH would appear to restore physiological miRNA levels, which are dysregulated in uRPL

Breast cancer in West Africa: molecular analysis of BRCA genes in early-onset breast cancer patients in Burkina Faso

Background Breast cancer (BC) is the most commonly diagnosed cancer and the second leading cause of cancer-related deaths among women in Africa after cervical cancer. Even if the epidemiological data are now aligned with those relating to industrialized countries, the knowledge concerning breast cancer in Africa, particularly in Western Africa, still lack clinical data, medical treatments, and the evaluation of genetic and non-genetic factors implicated in the etiology of the disease. The early onset and the aggressiveness of diagnosed breast cancers in patients of African ancestry strongly suggest that the genetic risk factor may be a key component, but so far, very few studies on the impact of germ line mutations in breast cancer in Africa have been conducted, with negative consequences on prevention, awareness and patient management. Through Next Generation sequencing (NGS), we analyzed all of the coding regions and the exon-intron junctions of BRCA1 and BRCA2 genes-the two most important genes in hereditary breast cancer-in fifty-one women from Burkina Faso with early onset of breast cancer with or without a family history. Results We identified six different pathogenic mutations (three in BRCA1, three in BRCA2), two of which were recurrent in eight unrelated women. Furthermore, we identified, in four other patients, two variants of uncertain clinical significance (VUS) and two variants never previously described in literature, although one of them is present in the dbSNP database. Conclusions This is the first study in which the entire coding sequence of BRCA genes has been analyzed through Next Generation Sequencing in Burkinabe young women with breast cancer. Our data support the importance of genetic risk factors in the etiology of breast cancer in this population and suggest the necessity to improve the genetic cancer risk assessment. Furthermore, the identification of the most frequent mutations of BRCA1 and BRCA2 in the population of Burkina Faso will allow the development of an inexpensive genetic test for the identification of subjects at high genetic cancer risk, which could be used to design personalized therapeutic protocols