Oxidative Properties of Blood-Derived Extracellular Vesicles in 15 Patients After Myocardial Infarction.

BACKGROUND In this study, we investigated the yield and composition of extracellular vesicles (EVs) derived from 40- to 60-year-old healthy male controls and post-myocardial infarction (post-MI) patients' blood samples and assessed their pro-inflammatory and oxidative-related properties. Our study aimed to determine the EV yield and composition differences between both groups and to find out if there were differences between EV-mediated oxidative stress reactions. MATERIAL AND METHODS Fifteen post-MI patients and 25 healthy individuals were included. EVs were isolated by ultracentrifugation and analyzed using nanotracking analysis (NTA), western blotting and fluorescent flow cytometry (FFC). Oxidative stress (OS) in blood samples was identified by measuring malondialdehyde concentration from serum, while EVs-induced OS was measured in the human vein endothelium cells (HUVEC) using H2DCFDA (2',7'-dichlorodihydrofluorescein diacetate) fluorescence as a marker. RESULTS We found higher EVs concentration in healthy controls than in the post-MI group (7.07±3.1 E+10 ml vs 3.1±1.9 E+10 ml, P<0.001) and a higher level of CD9-positive exosomes (MFI 275±39.5 vs 252±13, P<0.001). Post-MI patients' EVs carry pro-oxidative nicotinamide adenine dinucleotide phosphate (NADPH) oxidases isoforms NOX1 (NADPH oxidase 1), NOX5 (NADPH oxidase 5) and NOX2 (NADPH oxidase 2) and anti-oxidative thioredoxin, extracellular signal-regulated kinases 1/2 (ERK1/2), and protein kinase B (Akt B). In the post-MI EVs, there was a higher predominance of enzymes with anti-oxidative effects, leading to weaker OS-inducing properties in the HUVEC cells. CONCLUSIONS We conclude that post-MI patient blood sample EVs have stronger anti- than pro-oxidative properties and these could help fight against post-MI consequences.

Relationship Between Composition of Fatty Acid in Platelet Phospholipid Membrane and Markers of Oxidative Stress in Healthy Men and Men After a Myocardial Infarction.

BACKGROUND Oxidative stress (OS) is known to be extremely damaging for phospholipids in cell membranes, especially their polyunsaturated fatty acids (PUFAs). OS is known to be associated with increased platelet activation and thrombosis, which lead to cardiovascular lesions. The aim of this study was to investigate how changes in the composition of fatty acids (FAs) in the platelet phospholipid membrane correlate with OS in healthy men and in men who have experienced a myocardial infarction (post-MI men). MATERIAL AND METHODS FA methyl esters from the platelet phospholipid membrane of 79 apparently healthy and 20 post-MI men were identified using gas chromatography/mass spectrometry. Malondialdehyde (MDA) was measured in the blood serum using high-performance liquid chromatography, and platelet-white blood cell aggregates (PWAs) were analysed based on whole-blood flow cytometry. The composition of platelet membrane FAs was compared to MDA concentration (µg/l) and the percentage of PWA formation between healthy men and individuals who had suffered a myocardial infarction (MI). RESULTS Statistically, post-MI patients had a significantly higher concentration of blood serum MDA than those in the control group (p=0.000). The level of PUFAs was also higher in the platelet phospholipid membrane of post-MI patients than in healthy individuals (p=0.016). However, the percentage of PWA formation was lower in patients compared with the control group (p<0.05). CONCLUSIONS A higher level of blood serum MDA concentration due to OS stimulates platelets to incorporate more PUFAs into the phospholipid membrane, thereby affecting platelet activation. This may lead the individual to develop cardiovascular diseases in the future.

Changes in circulating endothelial microvesicles in men after myocardial infarction.

PURPOSE: The objective of the study was to determine the differences in the numbers of endothelial microvesicles (EMV) after myocardial infarction (MI) and their association with oxidative stress. MATERIALS AND METHODS: We included 15 post MI patients and 28 healthy controls. Samples were analysed by flow cytometry. We examined four EMV populations: 1) CD144+, CD42a-, CD61-, 2) CD144+, CD42a+, CD61-, 3) CD105+, CD42a-, CD61-and 4) CD31+, CD42a-, CD61-and determined a percentage of CD62e + EMV. Malondialdehyde concentration was determined by ultra-high performance liquid chromatography. RESULTS: The median of EMV counts differed between controls and patients in: CD105+ (10.91 microvesicles/µl vs. 33.68 microvesicles/µl, P = 0.006), CD144+, CD42a+ (312.87 microvesicles/µl vs. 73.29 microvesicles/µl, P < 0.001) and CD31+ (2 microvesicles/µl vs. 1.38 microvesicles/µl, P = 0.021). The median of percentage of CD62e expression differed between controls and patients in: CD105+ (1.35% vs. 14.8%, P < 0.001), CD144+, CD42a+ (56.45% vs. 98.99%, P < 0.001) and CD144+, CD42a- (173.03% vs. 215.56%) EMV. In patients, EMV counts correlated with low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC) and high-density lipoprotein cholesterol (HDL-C) concentrations: CD105+: R = -0.69, P = 0.004 (LDL-C), R = -0.64, P = 0.01 (TC); CD144+, CD42a-: R = -0.68, P = 0.005 (LDL-C), R = -0.63, P = 0.011 (TC); CD144+: R = -0.54, P = 0.038 (HDL-C) and CD144+, CD42a-, CD62e+: R = 0.78, P = 0.001 (HDL-C). In controls, HDL-C concentration correlated with CD105+ (R = -0.395, P = 0.038) and CD105+, CD62e+ (R = -0.716, P < 0.001) counts. Malondialdehyde concentration correlated with CD144+, CD42a- (P = 0.01, R = 0.48) and CD105+, CD62e+ (P = 0.012, R = 0.47) counts. CONCLUSIONS: Changes in EMV levels after the MI period were observed. Counts of EMV and their CD62e expression correlated with dyslipidaemia and oxidative stress.

Association of Platelet Membrane Fatty Acid Composition with Markers of Oxidative Stress in Healthy Men.

BACKGROUND Platelet membranes are extremely susceptible to peroxidation, forming a variety of lipid peroxides, including malondialdehyde (MDA), which has been implicated in the etiology of cardiovascular diseases. Moreover, platelet-leukocyte aggregates (PLAs) are known to contribute to advanced endothelial injury and atherogenesis. MATERIAL AND METHODS Fatty acid (FA) methyl esters of the platelet membranes of 79 apparently healthy men without any acute clinical condition at the time of the study were identified by GC/MS. MDA was measured by HPLC in blood serum, and PLAs were analyzed by whole-blood flow cytometry. Individuals were divided into quartiles according to MDA concentration and percentage of PLAs formation. The composition of platelet membrane FAs was compared to MDA concentration and the percentage of PLAs formation in apparently healthy individuals. RESULTS In quartiles (Q) with higher MDA concentration, percentage of C 16: 1ω7 (Q1 vs. Q3, p=0.021), C 20: 1ω9 (Q2 vs. Q4, p=0.028) and C 20: 5ω3 (Q2 vs. Q4, p=0.046) was lower. However, C 22: 5ω3 (Q1 vs. Q4, p=0.038) and total ω3 (Q1 vs. Q2, p=0.024) were higher. CONCLUSIONS MDA and the formation of platelet-monocyte aggregates stimulate the incorporation of monounsaturated fatty acids and polyunsaturated fatty acids in platelet phospholipid membranes, which may be a hallmark for a changed level of biologically active compounds required for the activation of future platelets.

Chronic and oxidative stress association with total count of endothelial microvesicles in healthy young male plasma.

BACKGROUND: Chronic and oxidative stress promotes injury to the endothelium. This happens early in the disease and novel biomarkers describing the rate of the damage may be important in early diagnostics and prevention. Microvesicles are shed from endothelial cells in response to oxidative stress, inflammation, coagulation, and angiogenesis. Their increased level in plasma could reflect the state of the endothelium. OBJECTIVES: The objective of this study was to test the association between oxidative and chronic stress markers, atherosclerosis risk factors and endothelial microvesicle (EMV) count in peripheral blood. MATERIAL AND METHODS: The study included 81 males, aged 25-55 years and apparently healthy. Venous blood samples were labeled with anti-CD144-FITC, anti-CD105-BV421, anti-CD42a-PerCP, anti-CD62e-PE, anti-CD31-APCy7, and anti-CD61-APC (BD Biosciences, San Jose, USA), and tested using a BD LSR Fortessa cytometer (BD Biosciences). Events were gated on forward and side-scattered light parameters. Malondialdehyde (MDA) and cortisol concentrations were measured using high-performance liquid chromatography (HPLC). RESULTS: Four populations of EMV expressing a combination of CD105+, CD31+, CD144+, and CD62e with CD42aor CD42a+ markers were examined. We found correlations between MDA concentration and hair cortisol and a total count of CD144+ microvesicles, and weak correlations with diastolic blood pressure (DBP) (p = 0.003, r = 0.324) and systolic blood pressure (SBP) (p = 0.016, r = 0.267), especially with the microvesicles carrying CD62e. There was a median difference of CD105+ microvesicle count between smoking (n = 13) and non-smoking (n = 68) individuals. A predictive model showed an association between CD144+ microvesicle counts with cortisol and MDA concentrations and waist circumference. CONCLUSIONS: In conclusion, our data and predictive model showed that the total counts of microvesicle populations were associated with stress-related parameters - cortisol and MDA concentrations; expression of CD62e in various populations of EMV and the ratio of CD144+ to CD105+/CD62e+ were associated with increased DBP and SBP, and also with total cholesterol concentration in healthy young male population.