Angiopoietin-2 as a biomarker of non-ST-segment elevation myocardial infarction in patients with or without type 2 diabetes.

Introduction: Angiopoietin-2 (Ang-2) is a novel marker of coronary artery disease (CAD) and diabetes (DM). The aim was to evaluate Ang-2 as a potential new biomarker of non-ST elevation myocardial infarction (NSTEMI) in patients with or without type 2 DM (T2DM). Material and methods: This was a multi-center, prospective study that included 138 (males: 91/66%) consecutive patients hospitalized due to NSTEMI, T2DM, or different cardiac disorders. The subjects were divided into four study groups: group A: 28 patients with NSTEMI and T2DM; group B: 47 patients with NSTEMI without T2DM; group C: 31 patients with T2DM, without a history of CAD; group D: 32 patients as a control group. Patients with NSTEMI underwent urgent coronarography. Clinical characteristics including biomarkers (hs-CRP, hsTnT, NT-proBNP, VEGF, HbA1c), SYNTAX SCORE, type of intervention (PCI vs. CABG), and number of implanted stents were taken into account in the analysis. Results: Serum Ang-2 concentrations were significantly higher in patients with NSTEMI (group A: 1769 pg/ml; group B: 1757 pg/ml) and patients with T2DM (group C: 1993 pg/ml) as compared to the patients without CAD and without T2DM (group D: 866.8 pg/ml; p < 0.05). The prognostic accuracy of Ang-2 in NSTEMI diagnosis was determined with the area under the ROC curve (area under curve (AUC) = 0.63). Conclusions: Angiopoietin-2 serum concentration is elevated in the presence of NSTEMI in patients with and without T2DM and does not correspond to the degree of myocardial injury and hemodynamic status. Ang-2 remains elevated also in patients with T2DM without a history of CAD.

FOXO1 and ANGPT2 relative gene expression in non-ST-segment elevation myocardial infarction among patients with or without type 2 diabetes.

INTRODUCTION: It is well known that chronic hyperglycemia or chronic inflammation leads to both FOXO1 and Ang-2 gene (ANGPT2) expression induction in endothelial cells. ANGPT2 and FOXO1 relative gene expression in peripheral blood cells in diabetes and myocardial ischemia were not researched extensively. AIM: Our objective was to evaluate ANGPT2 and FOXO1 gene expression in peripheral blood cells in patients with non-ST elevation myocardial infarction (NSTEMI), both with and without type 2 diabetes mellitus (T2DM), and compare them to the results obtained from T2DM and control subjects. MATERIAL AND METHODS: This was a multi-center, prospective study of 138 NSTEMI patients with/without T2DM, T2DM and a control group. FOXO1, ANGPT2, TBP (TATA box binding protein - as a reference gene) gene expression levels in peripheral blood cells were measured in each patient. Electrocardiography and echocardiography with assessment of ejection fraction (EF) were performed. Patients with NSTEMI underwent urgent (< 24 h) coronarography and the SYNTAX score and GRACE 2.0 score were calculated. RESULTS: The ANGPT2 gene relative expression in buffy coat in the analyzed samples was very low and detectable only in 11 patients from all groups (8.66% of all patients). The level of FOXO1 gene relative expression was significantly higher in patients with NSTEMI (median relative expression = 1.39) than in non-NSTEMI patients (median = 1.09) (W = 1578, p < 0.05) regardless of the presence of T2DM. The FOXO1 gene relative expression was not correlated with GRACE 2.0 score or SYNTAX score of NSTEMI patients. We did not observe any significant change in FOXO1 gene expression after successful angioplasty. CONCLUSIONS: On the basis of our results we can conclude that analyzing the ANGPT2 gene relative expression in peripheral blood cells has no role in assessment of CAD complexity among patients with and without T2DM. FOXO1 gene relative expression in blood peripheral cells is elevated in patients with NSTEMI regardless of the presence of T2DM. FOXO1 expression does not decrease after successful percutaneous coronary intervention and is not correlated with the severity of CAD in patients with NSTEMI.

MicroRNA-34a Acutely Regulates Synaptic Efficacy in the Adult Dentate Gyrus In Vivo.

Activity-dependent synaptic plasticity involves rapid regulation of neuronal protein synthesis on a time-scale of minutes. miRNA function in synaptic plasticity and memory formation has been elucidated by stable experimental manipulation of miRNA expression and activity using transgenic approaches and viral vectors. However, the impact of rapid miRNA modulation on synaptic efficacy is unknown. Here, we examined the effect of acute (12 min), intrahippocampal infusion of a miR-34a antagonist (antimiR) on medial perforant path-evoked synaptic transmission in the dentate gyrus of adult anesthetised rats. AntimiR-34a infusion acutely depressed medial perforant path-evoked field excitatory post-synaptic potentials (fEPSPs). The fEPSP decrease was detected within 9 min of infusion, lasted for hours, and was associated with knockdown of antimiR-34a levels. AntimiR-34a-induced synaptic depression was sequence-specific; no changes were elicited by infusion of scrambled or mismatch control. The rapid modulation suggests that a target, or set of targets, is regulated by miR-34a. Western blot analysis of dentate gyrus lysates revealed enhanced expression of Arc, a known miR-34a target, and four novel predicted targets (Ctip2, PKI-1α, TCF4 and Ube2g1). Remarkably, antimiR-34a had no effect when infused during the maintenance phase of long-term potentiation. We conclude that miR-34a regulates basal synaptic efficacy in the adult dentate gyrus in vivo. To our knowledge, these in vivo findings are the first to demonstrate acute (< 9 min) regulation of synaptic efficacy in the adult brain by a miRNA.

NMDA receptor-dependent regulation of miRNA expression and association with Argonaute during LTP in vivo.

microRNAs (miRNAs) are major regulators of protein synthesis in the brain. A major goal is to identify changes in miRNA expression underlying protein synthesis-dependent forms of synaptic plasticity such as long-term potentiation (LTP). Previous analyses focused on changes in miRNA levels in total lysate samples. Here, we asked whether changes in total miRNA accurately reflect changes in the amount of miRNA bound to Argonaute protein within the miRNA-induced silencing complex (miRISC). Ago2 immunoprecipitation was used to isolate RISC-associated miRNAs following high-frequency stimulation (HFS)-induced LTP in the dentate gyrus of anesthetized rats. Using locked-nucleic acid-based PCR cards for high-throughput screening and independent validation by quantitative TaqMan RT-PCR, we identified differential regulation of Ago2-associated and total miRNA expression. The ratio of Ago2/total miRNA expression was regulated bidirectionally in a miRNA-specific manner and was largely dependent on N-methyl-D-aspartate receptor (NMDA) activation during LTP induction. The present results identify miRNA association with Ago2 as a potential control point in activity-dependent synaptic plasticity in the adult brain. Finally, novel computational analysis for targets of the Ago2-associated miRNAs identifies 21 pathways that are enriched and differentially targeted by the miRNAs including axon guidance, mTOR, MAPK, Ras, and LTP.

Object-based saccadic selection during scene perception: evidence from viewing position effects.

The goal of the present study was to further test the hypothesis that objects are important units of saccade targeting and, by inference, attentional selection in real-world scene perception. To this end, we investigated where people fixate within objects embedded in natural scenes. Previously, we reported a preferred viewing location (PVL) close to the center of objects (Nuthmann & Henderson, 2010). Here, we qualify this basic finding by showing that the PVL is affected by object size and the distance between the object and the previous fixation (i.e., launch site distance). Moreover, we examined how within-object fixation position affected subsequent eye-movement behavior on the object. Unexpectedly, there was no refixation optimal viewing position (OVP) effect for objects in scenes. Where viewers initially placed their eyes on an object did not affect the likelihood of refixating that object, suggesting that some refixations on objects in scenes are made for reasons other than insufficient visual information. A fixation-duration inverted-optimal viewing (IOVP) effect was found for large objects: Fixations located at object center were longer than those falling near the edges of an object. Collectively, these findings lend further support to the notion of object-based saccade targeting in scenes.