Plasma levels of miR-29b and miR-200b in type 2 diabetic retinopathy.

MicroRNAs (miRNAs/miRs) are involved in the pathogenesis of diabetes mellitus and its chronic complications, and their circulating levels have emerged as potential biomarkers for the development and progression of diabetes. However, few studies have examined the expression of miRNAs in diabetic retinopathy (DR) in humans. This case-control study aimed to investigate whether the plasma levels of miR-29b and miR-200b are associated with DR in 186 South Brazilians with type 2 diabetes (91 without DR, 46 with non-proliferative DR and 49 with proliferative DR). We also included 20 healthy blood donors to determine the miRNA expression in the general population. Plasma levels of miR-29b and miR-200b were quantified by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Proliferative DR was inversely associated with plasma levels of miR-29b (unadjusted OR = 0.694, 95% CI: 0.535-0.900, P = 0.006) and miR-200b (unadjusted OR = 0.797, 95% CI: 0.637-0.997, P = 0.047). However, these associations were lost after controlling for demographic and clinical covariates. In addition, patients with type 2 diabetes had lower miR-200b levels than blood donors. Our findings reinforce the importance of addressing the role of circulating miRNAs, including miR-29 and miR-200b, in DR.

Plasma levels of microRNA-21, -126 and -423-5p alter during clinical improvement and are associated with the prognosis of acute heart failure.

MicroRNAs are associated with myocardial damage and heart failure (HF). The present study investigated whether the plasma levels of microRNA (miR)­21, ­126 and ­423­5p alter according to the (de)compensated state of patients with HF and are associated with all­cause mortality. In 48 patients with HF admitted to the emergency room for an episode of acute decompensation, blood samples were collected to measure miR and B­type natriuretic peptide levels within 24 h of hospital admission, at the time of hospital discharge, and a number of weeks post­discharge (chronic stable compensated state). Levels of miR­21, miR­126 and miR­423­5p increased between admission and discharge, and decreased following clinical compensation. During follow­up (up to 48 months), 38 patients (79%) were rehospitalized at least once and 21 patients (44%) succumbed. Patients who had increased levels of miR­21 and miR­126 at the time of clinical compensation exhibited better 24­month survival and remained rehospitalization­free for a longer period compared with those with low levels. Additionally, patients whose levels of miR­423­5p increased between admission and clinical compensation experienced fewer hospital readmissions in the 24 months following the time of clinical compensation compared with those who had decreased levels. It was concluded that the plasma levels of miR­21, miR­126 and miR­423­5p altered during clinical improvement and were associated with the prognosis of acute decompensated HF.

N-acetylcysteine Plus Deferoxamine Improves Cardiac Function in Wistar Rats After Non-reperfused Acute Myocardial Infarction.

The antioxidant N-acetycysteine can turn into a prooxidant molecule in presence of iron ions. Thus, our goal was to test if the association of N-acetylcysteine (NAC) and an iron chelator (deferoxamine--DFX) in a rodent model of acute myocardial infarction (AMI) improves cardiac function. Male Wistar rats were subjected to a SHAM surgery or AMI. The animals were randomized: vehicle, NAC (25 mg/kg for 28 days), DFX (40 mg/kg for 7 days), or NAC plus DFX (NAC plus DFX, respectively). Animals were killed 28 days after the AMI. Animals treated with NAC/DFX showed an increase in left ventricular ejection fraction at 28 days when compared with vehicle group (45.2 ± 10.9 % vs. 34.7 ± 8.7 %, p = 0.03). Antioxidant effect of NAC/DFX treatment decreased 4-hydroxynonenal when compared to AMI group (p = 0.06). In conclusion, we showed beneficial effect of NAC/DFX association in improving left ventricle function in an experimental AMI.

An analysis of the global expression of microRNAs in an experimental model of physiological left ventricular hypertrophy.

BACKGROUND: MicroRNAs (miRs) are a class of small non-coding RNAs that regulate gene expression. Studies of transgenic mouse models have indicated that deregulation of a single miR can induce pathological cardiac hypertrophy and cardiac failure. The roles of miRs in the genesis of physiological left ventricular hypertrophy (LVH), however, are not well understood. OBJECTIVE: To evaluate the global miR expression in an experimental model of exercise-induced LVH. METHODS: Male Balb/c mice were divided into sedentary (SED) and exercise (EXE) groups. Voluntary exercise was performed on an odometer-monitored metal wheels for 35 days. Various tests were performed after 7 and 35 days of training, including a transthoracic echocardiography, a maximal exercise test, a miR microarray (miRBase v.16) and qRT-PCR analysis. RESULTS: The ratio between the left ventricular weight and body weight was increased by 7% in the EXE group at day 7 (p<0.01) and by 11% at day 35 of training (p<0.001). After 7 days of training, the microarray identified 35 miRs that were differentially expressed between the two groups: 20 were up-regulated and 15 were down-regulated in the EXE group compared with the SED group (p = 0.01). At day 35 of training, 25 miRs were differentially expressed: 15 were up-regulated and 10 were decreased in the EXE animals compared with the SED animals (p<0.01). The qRT-PCR analysis demonstrated an increase in miR-150 levels after 35 days and a decrease in miR-26b, miR-27a and miR-143 after 7 days of voluntary exercise. CONCLUSIONS: We have identified new miRs that can modulate physiological cardiac hypertrophy, particularly miR-26b, -150, -27a and -143. Our data also indicate that previously established regulatory gene pathways involved in pathological LVH are not changed in physiological LVH.

Transcoronary gradient of plasma microRNA 423-5p in heart failure: evidence of altered myocardial expression.

CONTEXT: Elevated plasmatic microRNAs (miRs) are observed in heart failure (HF). However, the cardiac origin of these miRs remains unclear. OBJECTIVE: We calculated transcoronary gradients of miR-29b, miR-133a and miR-423-5p in 17 outpatients with stable systolic HF and in controls without structural cardiac disease. MATERIALS AND METHODS: MicroRNAs were measured by quantitative real-time polymerase chain reaction. RESULTS: Positive transcoronary miR gradients were observed in patients with HF but not in controls (p = 0.03). B-type natriuretic peptide (BNP) moderately correlated with the transcoronary gradients of miR-133a and miR-423-5p. DISCUSSION AND CONCLUSIONS: The difference in transcoronary gradients between HF outpatients and controls suggests that miR-423-5p has a cardiac origin. The positive correlation between miR-423-5p and BNP transcoronary gradients supports this hypothesis.

Serum levels and polymorphisms of matrix metalloproteinases (MMPs) in carotid artery atherosclerosis: higher MMP-9 levels are associated with plaque vulnerability.

CONTEXT: Matrix metalloproteinases are involved in atherosclerosis and plaque vulnerability. OBJECTIVE: To investigate serum levels and genetic polymorphisms of matrix metalloproteinases (MMPs) -1, -3 and -9 in patients submitted to carotid endarterectomy. METHODS: Genetic polymorphisms were evaluated using polymerase chain reaction (PCR-RFLP); serum levels were measured using ELISA; histological sections were stained with Picrosirius Red to analyze the fibrous cap thickness, lipid core and collagen content and with hematoxylin--eosin to detect the presence of intraplaque hemorrhage. RESULTS: MMP-9 serum levels were significantly higher in patients with a thinner fibrous cap (p = 0.033) or acute or recent intraplaque hemorrhage (p = 0.008) on histology, as well as in patients with previous stroke (p = 0.009) or peripheral vascular disease (p = 0.049). No consistent associations were observed between different MMP genotypes and fibrous cap thickness, lipid core, collagen content or intraplaque hemorrhage. CONCLUSIONS: MMP-9 serum levels were consistently associated with markers of carotid atherosclerosis and lesion vulnerability, whereas specific MMP genotypes were not.

Polymorphisms of endothelial nitric oxide synthase gene in systolic heart failure: an haplotype analysis.

BACKGROUND: Endothelial nitric oxide synthase (eNOS) gene polymorphisms have been associated with the pathogenesis of cardiovascular diseases, but few studies have evaluated the role of eNOS haplotypes on the risk and prognosis of heart failure (HF). This prospective study was designed to analyze the impact of three eNOS polymorphisms (T-786C, VNTR4a/b and Glu298Asp) and their haplotypes on the susceptibility and clinical outcomes in HF outpatients with systolic dysfunction. METHODS AND RESULTS: We conducted a case-control and a cohort study in which 316 HF patients and 360 healthy controls were recruited from a tertiary care university hospital. DNA was extracted from peripheral blood and eNOS polymorphisms were detected by PCR or PCR-RFLP. Patients were predominantly men, had a mean left ventricular ejection fraction of 31% and were followed-up for a median of 41months; there were 96 deaths, including 58 HF-related deaths. Genotype distribution of the eNOS T-786C, VNTR 4a/b and Glu298Asp was similar between HF patients and controls. Haplotype frequencies differed between HF patients and controls only in African-Brazilians (p=0.043). African-Brazilian patients that carried the haplotype -786C/4b/Asp298 had a better prognosis than patients that carried other haplotypes (log rank p value=0.016 for all-cause mortality). In a Cox proportional hazard model adjusted for clinical variables of risk, the -786C/4b/Asp298 haplotype remained as an independent genetic predictor of survival (adjusted HR=0.11; 95% CI=0.01-0.83; p=0.03). CONCLUSIONS: The -786C/4b/Asp298 eNOS haplotype had a significant impact on HF susceptibility and prognosis, particularly in African-Brazilian patients.

Ventricular dysfunction and dilation in severe sepsis and septic shock: relation to endothelial function and mortality.

PURPOSE: The aim of this study was to evaluate echocardiography-based indices of myocardial function and markers of vascular inflammation and endothelial dysfunction in the early phases of severe sepsis. MATERIAL AND METHODS: Forty-five adult patients (67% women; age 51 ± 18 years; Acute Physiology and Chronic Health Disease Classification System II score, 23 ± 7) admitted to the intensive care unit up to 24 hours after fulfilling criteria for severe sepsis or septic shock were studied. Clinical, laboratorial (endothelin 1 [ET1], vascular cellular adhesion molecule 1), and echocardiographic data were collected within the first 24 hours and again 72 hours and 7 days after admission. RESULTS: Intrahospital mortality was 33% (15 deaths). Left ventricular (LV) dysfunction (LV ejection fraction <55%) was identified in 15 (33%) patients, whereas right ventricular (RV) dysfunction (RV tissue Doppler peak systolic velocity [RV-Sm] <12 cm/s) was present in 14 (30%) patients. LogET1 was increased in patients with LV dysfunction (2.3 ± 0.6 vs 1.8 ± 0.4 pg/mL; P = .01) and RV dysfunction (2.5 ± 0.5 vs 1.8 ± 0.4 pg/mL; P < .001) and had negative correlations with LV ejection fraction (r = -0.50; P = .002) and RV-Sm (r = -0.67; P < .001). Left ventricular end-diastolic diameter, RV-Sm, and diastolic dysfunction were able to discriminate survivors from nonsurvivors, and the combination of these parameters identified groups of very low and high risk. CONCLUSION: Both LV and RV systolic dysfunctions are prevalent in severe sepsis, being directly associated with markers of endothelial dysfunction. Left ventricular nondilation, RV dysfunction, and diastolic dysfunction seem related to poor prognosis in this scenario.

Endothelial dysfunction assessed by brachial artery ultrasound in severe sepsis and septic shock.

PURPOSE: Noninvasive evaluation of endothelial function may be accomplished by ultrasound assessment of flow-mediated vasodilation (FMD) of the brachial artery. This study aims to investigate the role of FMD analysis on intrahospital prognosis of patients with sepsis. METHODS: Adult patients admitted to the intensive care unit with severe sepsis or septic shock were consecutively included. Brachial artery FMD was measured upon admission, after 24 and 72 hours. A group of apparently healthy subjects paired for sex and age was used as controls. Patients were followed up to discharge or death. RESULTS: We studied 42 patients (mean age, 51 ± 19 years) with sepsis predominantly of abdominal or respiratory etiology (75%). Acute Physiology And Chronic Health Evaluation II risk score was 23 ± 7, and intrahospital mortality rate was 33%. Flow-mediated vasodilation in septic patients was significantly lower than in healthy controls (1.5 ± 7% vs 6 ± 4%, P < .001). Most of the nonsurvivors (86%) showed a decline in sequential FMD analyses, whereas only 43% of survivors showed a reduction of FMD (P = .01). In nonsurvivors, FMD was significantly lower 72 hours after sepsis onset (-3.3% ± 10% vs 5.2% ± 4%; P < .05; time-group interaction P value = .03). CONCLUSIONS: Brachial FMD is altered in septic patients with hemodynamic instability, and its deterioration may be an early marker of unfavorable prognosis.

Polymorphisms of matrix metalloproteinases in systolic heart failure: role on disease susceptibility, phenotypic characteristics, and prognosis.

BACKGROUND: The role of matrix metalloproteinases (MMPs) polymorphisms on heart failure (HF) susceptibility, phenotypic characteristics, and prognosis has been poorly explored. METHODS AND RESULTS: We studied 313 HF patients with left ventricular systolic dysfunction and 367 healthy control subjects. Genotyping of MMP-1 (-1607 1G/2G), MMP-3 (-1171 5A/6A), and MMP-9 (-1562 C/T) polymorphisms was performed by polymerase chain reaction. Allelic and genotypic frequencies of MMP-1, -3, and -9 were similar in HF patients and controls. MMP1 2G allele carriers were positively associated to ischemic etiology and history of myocardial infarction (all P values <.05). Patients were followed-up for a median of 40 months and 58 HF-related deaths occurred during this period. HF-related survival was significantly better in MMP1 2G allele carriers (71% versus 42% for 1G/1G patients, P = .002) and in MMP-3 6A allele carriers (70% versus 61% for 5A/5A patients, P = .064), particularly in non-ischemic patients (P = .039). MMP1 2G allele was independently associated to HF survival after adjustment for several other predictors of risk (hazard ratio 0.47, 95% confidence interval 0.27 to 0.82; P = .008). CONCLUSIONS: MMP-1, -3, and -9 polymorphisms were not associated to HF susceptibility. However, MMP1 2G allele carriers were related to a higher prevalence of ischemic etiology among patients with systolic HF and better HF-related prognosis.