[Methylation of Regulatory Regions of DNA Repair Genes in Carotid Atherosclerosis].

The status of DNA methylation in the human genome changes during the pathogenesis of common diseases and acts as a predictor of life expectancy. Therefore, it is of interest to investigate the methylation level of regulatory regions of genes responsible for general biological processes that are potentially significant for the development of age-associated diseases. Among them there are genes encoding proteins of DNA repair system, which are characterized by pleiotropic effects. Here, results of the targeted methylation analysis of two regions of the human genome (the promoter of the MLH1 gene and the enhancer near the ATM gene) in different tissues of patients with carotid atherosclerosis are present. Analysis of the methylation profiles of studied genes in various tissues of the same individuals demonstrated marked differences between leukocytes and tissues of the vascular wall. Differences in methylation levels between normal and atherosclerotic tissues of the carotid arteries were revealed only for two studied CpG sites (chr11:108089866 and chr11:108090020, GRCh37/hg19 assembly) in the ATM gene. Based on this, we can assume the involvement of ATM in the development of atherosclerosis. "Overload" of the studied regions with transcription factor binding sites (according to ReMapp2022 data) indicate that the tissue-specific nature of methylation of the regulatory regions of the MLH1 and ATM may be associated with expression levels of these genes in a particular tissue. It has been shown that inter-individual differences in the methylation levels of CpG sites are associated with sufficiently distant nucleotide substitutions.

[The Integrated Approach to Improving Efficiency and Safety of Anticoagulation Therapy in Patients With Prosthetic Mitral Valve].

AIM: To assess advantages of integrated approach to improvement of efficiency and safety of warfarin therapy after heart valve replacement. MATERIALS AND METHODS: We included in this study 118 patients who had undergone simultaneous mitral valve replacement and maze procedure. Group 1 patients (n=37) underwent just sinus rhythm restoration, group 2 patients (n=54) underwent sinus rhythm restoration and participated in a patient education program, group 3 patients (n=27) underwent sinus rhythm restoration, participated in a patient education program, and were subjected to pharmacogenetic testing for warfarin sensitivity. In examination of patients we used clinical, demographic, and instrumental methods. Estimation of the time in the therapeutic range (TTR) of an international normalized ratio (INR) was used as a measure of warfarin therapy quality, and the Kaplan-Meier method was applied for analysis of hemorrhagic and thrombotic complications. RESULTS: TTR was 42 % in group 1, 68 % in group 2 (p=0.0327), and 82 % in group 3 (p=0.0019). Application of integrated approach was associated with absence of hemorrhagic and thrombotic complications within one year after heart valve replacement. CONCLUSION: The integrated approach comprising restoration of sinus rhythm, patient education, and pharmacogenetic testing for warfarin sensitivity was associated with improved anticoagulation control, and prevention of hemorrhagic and thrombotic complications.

[ Mitochondrial DNA polymorphism association with myocardial infarction and prognostic signs for atherosclerosis].

We have performed association analysis for mtDNA most common variants and haplogroups with myocardial infarction and some prognostic characteristics in patients. Comparison of patients (N=406) and controls (N=183) has shown higher frequency of HV0 haplogroup in patients (6.9% vs. 2.2%; p=0.033). Patients with early infarction (before age 55), comparing to patiens older than 55 and the first infarction, had higher frequency of 16189C variant (24.1 vs. 12.5%; p=0.008); also, haplogroup U2e was registered only in the subgroup with early infarction (4.4%; p=0.004). On the other side, haplogroup U5 was less frequent in the patients with early infarction (5.1% vs. 15.4%; p=0.002). The patients with recurring cardiovascular incidents during one year follow-up had higher frequency of haplogroup H1 (20% versus 4.5% in the patients without complications, p=0.002) and variant 16189C (30% versus 13.5%; p=0.018). Haplogroup U5 was more frequent in the group of patients with left ventricular ejection fraction less than 40%: 17.1% comparing to 8.2% in the group with ejection fraction>40%; p=0.034. The results suggest that mtDNA polymorphism contributes to coronary atherosclerosis. The associations could be explained by the polymorphism effect on oxidative phosphorylation and reactive oxygen production in mitochondria.

[TOMM40 gene polymorphism association with lipid profile].

The distribution of the allele and genotype frequency for the TOMM40 gene polymorphic variants rs741780, rs157580, rs1160985, rs2075650, and rs8106922 was analyzed in a sampling of ethnic Russians from the city of Kemerovo. The study of the structure of linkage disequilibrium in terms of five studied polymorphic variants showed the presence ofa haplotype block 2 Kb in length, which includes three polymorphic variants, i.e., rs741780, rs1160985, and rs8106922. The differences in the frequencies of alleles and genotypes in terms of the polymorphic rs2075650 and rs157580 variants between ethnic Russians from the city of Kemerovo and other European populations were detected. It was discovered that polymorphic variants of TOMM40 rs741780, rs1160985, and rs8106922 are associated with serum triglyceride concentrations. In men, the polymorphic variant rs2075650 is associated with low-density lipoprotein cholesterol levels. In women, the polymorphic variant rs741780 is associated with diastolic blood pressure levels.

[Effect of an educational program on effectiveness and safety of anticoagulant therapy in patients with prostheses of cardiac valves].

We analyzed effectiveness and safety of anticoagulant therapy in patients with prostheses of cardiac valves at the background of educational program and without special training. We revealed positive effect of educational program during participation in which in 80 cases (67.8%) patients determined international normalized ratio every month and in 50 of them (62,5%) level of hypocoagulation corresponded to target range (p=0.001). At the background of educational program rate of thrombotic complications was 2.73% per patient year, at the background of no educational program - 4.90% per patient year (p=0.040) while rates of hemorrhagic complications were 2.73 and 7.20% per patient year, respectively (p=0.002).

[Prevalence of alleles of polymorphic variants Leu33Pro and Leu66Arg gene ITGB3 among inhabitants of Siberia].

The frequency of the polymorphic variant T196C (Leu33Pro, rs5918) of ITGB3 gene was studied in several groups of inhabitants of Siberia, including pregnant women with reproductive disorders (n = 186), patients with acute coronary syndrome (n = 330), and population control (n = 858). The frequency of the rare PLA2 allele among residents of Tomsk and Kemerovo was 14.7 and 15.0% respectively. There were no differences in the allele and genotype frequencies of polymorphic variant between patients with acute coronary syndrome and the control group (p = 0.925, p = 0.622). The highest frequency of abnormal PLA2 allele (22.1%) and the PLA2/PLA2 genotype (8.8%) was observed among women, who had miscarried, which was significantly different from the frequency of this allele and genotype in the control group (14.7%, p = 0.017; 2.1%, p = 0.0009). Sequencing showed that all samples with the nonspecific band had the polymorphic rs5918 variant and rs36080296 mutations (T216G, Leu66Arg). The frequency of the rs36080296 mutation among the residents of Siberia was 0.51%. Among the women with reproductive disorders, the frequency of rs36080296 was 2.7%, while in the group who suffered from miscarriages, it was 4.4%; this was different from the frequency in the control group (0.08%, p = 0.2 x 10(-6)). The accumulation of mutations was also observed among men with acute coronary syndrome (0.6%), but the differences from the control group (0%) had no statistical significance.