Machine-learning facilitates selection of a novel diagnostic panel of metabolites for the detection of heart failure.

The metabolic derangement is common in heart failure with reduced ejection fraction (HFrEF). The aim of the study was to check feasibility of the combined approach of untargeted metabolomics and machine learning to create a simple and potentially clinically useful diagnostic panel for HFrEF. The study included 67 chronic HFrEF patients (left ventricular ejection fraction-LVEF 24.3 ± 5.9%) and 39 controls without the disease. Fasting serum samples were fingerprinted by liquid chromatography-mass spectrometry. Feature selection based on random-forest models fitted to resampled data and followed by linear modelling, resulted in selection of eight metabolites (uric acid, two isomers of LPC 18:2, LPC 20:1, deoxycholic acid, docosahexaenoic acid and one unknown metabolite), demonstrating their predictive value in HFrEF. The accuracy of a model based on metabolites panel was comparable to BNP (0.85 vs 0.82), as verified on the test set. Selected metabolites correlated with clinical, echocardiographic and functional parameters. The combination of two innovative tools (metabolomics and machine-learning methods), both unrestrained by the gaps in the current knowledge, enables identification of a novel diagnostic panel. Its diagnostic value seems to be comparable to BNP. Large scale, multi-center studies using validated targeted methods are crucial to confirm clinical utility of proposed markers.

LC-MS-based serum fingerprinting reveals significant dysregulation of phospholipids in chronic heart failure.

Cardiac and extracardiac lipid metabolism is known to be significantly altered in the course of the heart failure with reduced ejection fraction (HF-REF), however the precise mechanisms are not fully elucidated. The aim of the study was to use of untargeted metabolomics to identify and validate changes in the blood metabolites profile, occurring as a result of HF-REF development. The analyses were performed first in the derivation set (36 chronic HF-REF patients and 19 controls without the disease) and repeated in validation cohort (31 chronic HF-REF patients and 20 controls). Independent analyses of both sets revealed statistically significant decline in intensities of phosphatidylcholine (PC): 34:4 and 36:5, lysophosphatidylcholine (lyso-PC): 14:0, 15:0, 18:0, 18:2, 20:3, lysophosphatidylethanolamine (lyso-PE): 18:1 and 18:2 in chronic HF-REF patients. More symptomatic patients and those with ischaemic etiology of HF-REF presented greater deficit in phospholipids (PLs) intensities. The decrease of identified PLs intensities (as compared to controls) correlated with decreased serum cholesterol level, impaired renal function, reduced exercise capacity, enhanced ventilatory response and metabolic parameters associated with altered fatty acids oxidation. In multiple regression analysis PLs deficit was significantly associated with age, carnitines serum intensity, renal function, uric acid, cholesterol level. In conclusion, HF-REF is associated with significant disturbances in phospholipids metabolism. Greater reduction in serum intensities of particular identified PLs is associated with older age, worse clinical condition, impaired oxidative muscle metabolism and enhanced catabolic status.

Metabolomics - A wide-open door to personalized treatment in chronic heart failure?

Heart failure (HF) is a complex syndrome representing a final stage of various cardiovascular diseases. Despite significant improvement in the diagnosis and treatment (e.g. ACE-inhibitors, ß-blockers, aldosterone antagonists, cardiac resynchronization therapy) of the disease, prognosis of optimally treated patients remains very serious and HF mortality is still unacceptably high. Therefore there is a strong need for further exploration of novel analytical methods, predictive and prognostic biomarkers and more personalized treatment. The metabolism of the failing heart being significantly impaired from its baseline state may be a future target not only for biomarker discovery but also for the pharmacologic intervention. However, an assessment of a particular, isolated metabolite or protein cannot be fully informative and makes a correct interpretation difficult. On the other hand, metabolites profile analysis may greatly assist investigator in an interpretation of the altered pathway dynamics, especially when combined with other lines of evidence (e.g. metabolites from the same pathway, transcriptomics, proteomics). Despite many prior studies on metabolism, the knowledge of peripheral and cardiac pathophysiological mechanisms responsible for the metabolic imbalance and progression of the disease is still insufficient. Metabolomics enabling comprehensive characterization of low molecular weight metabolites (e.g. lipids, sugars, organic acids, amino acids) that reflects the complete metabolic phenotype seems to be the key for further potential improvement in HF treatment (diet-based or biochemical-based). Will this -omics technique one day open a door to easy patients identification before they have a heart failure onset or its decompensation?

Diverse effects of prolonged physical training on learning of the delayed non-matching to sample by rats.

The physiological effects of physical exercise have been extensively studied. Nevertheless, its influence on cognitive functioning remains a matter of controversy. In this study we have attempted to assess the effects of repeated exercise (6 weeks of daily treadmill running, meant to resemble human physical training), on parallel learning of a complex task [delayed non matching to sample (DNMS)] by rats. The trained rats appeared to learn the procedure slower and made a significantly lower percentage of correct choices (P<0.01) as compared to those in the non-trained control group. However, when only those rats, from both the groups, which reached the criterion of 80% correct choices in two consecutive sessions were compared, no significant differences were observed. These results suggest an adverse influence of long term physical exercise on rats' ability to learn complex tasks, but only by the 'poor performers'. The 'good performers' were insensitive to the deleterious effects of the exercise.

Interleukin 6 is not necessary for STAT3 phosphorylation and myocardial hypertrophy following short term beta-adrenergic stimulation.

PURPOSE: In recent years several reports have suggested involvement of interleukin 6 (IL-6) in beta-adrenergic effects on myocardium, particularly in enhancement of STAT3 phosphorylation (downstream signal transducer of IL-6). Here we present a study of isoproterenol effects on hearts of IL-6 deficient mice. METHODS: Male 12 week old C57Bl6/J mice and age and sex matched mice from IL-6 knockout strain (C57Bl6/J(IL6-/-)) received a single intraperitoneal bolus of either isoproterenol (15 mg/kg) or placebo (0.9% NaCl) and were sacrificed after 1 or 24 hours (n=8 in each group). Another group of mice from both genotypes received a three-day isoproterenol treatment (20 mg/kg every 8h). Activation of STAT3 and MEK/ERK pathways were assessed after a single dose of isoproterenol by means of western blotting. RESULTS: After injection of placebo a significantly lower level of STAT3 phosphorylation was observed in IL-6 KO animals. This difference was abolished after isoproterenol both at 1 and 24-hour time points. Isoproterenol produced potent and rapid activation of both STAT3 and MEK/ERK pathways that returned to the levels of placebo treated controls after 24 hours. Lack of IL-6 did not affect phosphorylation of ERKs. Three-day treatment with isoproterenol caused significant increase of indices of RV and LV hypertrophy in both WT and IL-6 KO animals with no significant differences between genotypes. CONCLUSION: IL-6 is not necessary for isoproterenol induced STAT3 phosphorylation, but may affect activation of this pathway by mild non-specific stimuli. Lack of IL-6 does not affect activation of MEK/ERK pathway nor cardiac hypertrophy by beta-adrenergic agonists.

The rs1801133 polymorphism of methylenetetrahydrofolate reductase gene- the association with 5-year survival in patients with ST-elevation myocardial infarction.

PURPOSE: Methylenetetrahydrofolate reductase (MTHFR) is an enzyme involved in endothelial nitric oxide synthase (eNOS) coupling and homocysteine metabolism. The rs1801133 polymorphism of the MTHFR gene affects risk of coronary artery disease. We assessed its influence on 5-year survival of patients with ST-elevation acute myocardial infarction (STEMI). MATERIAL/METHODS: The study group comprised consecutive patients with STEMI. Genotyping was performed with a TaqMan SNP Genotyping Assay using the ABI 7500 Real Time PCR System (Applied Biosystems). The analyzed end-point was all-cause 5-year survival. RESULTS: The study group comprised 637 patients (mean age 62.3 ± 11.9 years; 25.1% females, n=160; 5-year mortality 16.3%, n=104). The percentages of TT, CT and CC genotypes were: 10.8 (n=69), 39.7 (n=253) and 49.45 (n=315), respectively. No significant differences in clinical characteristics were identified between the genotypes (p>0.05 for all parameters). Eleven (15.9%) TT homozygotes, 40 (15.8%) heterozygotes and 53 (16.8%) CC homozygotes died during follow up (p=0.99 log-rank test). TT homozygotes presented only weak and insignificant tendency towards higher mortality rates in subgroups of patients ≤75 years old (15.6 vs. 11.54%, p=0.35) or with intermediate risk according to the GRACE risk score (13.3% vs. 8.76%, p=0.42). CONCLUSIONS: The rs1801133 polymorphism did not show significant association with 5-year survival.

The effects of moderate physical exercise on cardiac hypertrophy in interleukin 6 deficient mice.

PURPOSE: Prolonged physical training leads to compensatory changes in cardiovascular system. One of the most important of them is cardiac hypertrophy. The knowledge, which factors contribute to cardiomyocyte hypertrophy caused by physical exercise is still incomplete. Interleukin 6 (IL6) secreted by contracting skeletal muscles may affect cardiac hypertrophy and remodeling. The aim of the study was to investigate the role of IL6 in exercise induced cardiac hypertrophy. MATERIAL AND METHODS: Female mice lacking functional IL6 gene C57BL6/J(IL6-/-tm1Kopf) (IL6KO) and age and sex matched controls C57BL6/J (WT) were subjected to 6 week swimming regime. Twenty-four hours after the last training session the mice were sacrificed, hearts were excised and weighed. Two other groups of sex and strain matched mice (9 in each group) not subjected to physical training, were sacrificed and served as controls. Weights of the heart and the left ventricle were related independently to the body weight and the tibia length as measures of hypertrophy. Statistical analysis was performed using multifactorial ANOVA and the Fisher test. RESULTS: There was significantly higher heart/body weight ratio in both groups of mice which were trained as compared to the respective sedentary animals [F(3,30) = 31.085 p < 0.001] There were, however, no significant differences between respective WT and IL6KO groups. Similar relations were found for the left ventricle and also when the weights of the heart and the LV were related to the tibia length. CONCLUSION: IL6 is not necessary for cardiac hypertrophy induced by prolonged moderate physical exercise in mice. Additional study is warranted to elucidate this phenomenon.

Low dose rofecoxib, inflammation and prostacyclin synthesis in acute coronary syndromes.

PURPOSE: To assess the influence of low dose rofecoxib on inflammatory mediators and prostacyclin synthesis in patients with acute coronary syndromes (ACS) in a short-term follow up. MATERIAL AND METHODS: Twenty nine patients with ACS without ST elevation were randomized to simvastatin alone or together with low dose rofecoxib. Serum levels of interleukin 6 (IL-6), 6-keto-PGF-1alpha--stable product of prostacyclin (PGT2) and hs-C-reactive protein (hs-CRP) were assessed on enrollment and after 30-day follow up. RESULTS: Combination of rofecoxib with statin significantly decreased levels of hs-CRP after one month therapy (5.21 mg/l +/- 4.12 vs 2.11 mg/l +/- 2.1; p=0.0092). This effect was not evident in a group on statin alone (3.95 mg/l +/- 3.33 vs 2.48 mg/l +/- 2.39; p=0.31). 6-keto-PGF-1alpha increased not significantly in both groups. IL-6 concentration has not changed during follow up. CONCLUSIONS: Low dose of selective COX-2 inhibitor exerts significant anti-inflammatory effect and does not diminish PG12 synthesis in study group of patients with ACS.

Monitoring treatment of pulmonary carcinomas by serial determination of monoamine oxidase and diamine oxidase in blood serum.

We investigated monoamine oxidase (MAO--E.C. 1.4.3.4.) and diamine oxidase (DAO--E. C. 1.4.3.6.) in the serum of patients with lung cancer, treated with chemo- and radiotherapy. These enzyme activities were determined with tyramine and putrescine as substrates. The MAO activities of serum and DAO serum increased notably in some cases of lung cancer. These results are discussed in light of the postulated role of this enzyme in cell division and in the tumor development process.