[Transcription of DNA-Methyltransferases in Endothelial Cells Exposed to Mitomycin C]

DNA-methyltransferases catalyze DNA methylation in the CpG sites, which play an important role in the maintenance of genome stability. The association between DNA methylation and genotoxic stress resulting in the action of various clastogens has been shown. Genotoxic stress is one of the triggers of endothelial dysfunction. In this study, the transcription of DNMT1, DNMT3A and DNMT3B genes in coronary (HCAEC) and internal thoracic (HITAEC) artery endothelial cells exposed to alkylating mutagen mitomycin C was studied using quantitative polymerase chain reaction. In HCAEC exposed to mitomycin C, DNMT1 transcription is 1.7-fold higher compared to the unexposed control. After elimination of the mutagen from the cultures followed by 24-hours of cultivation, a 2-fold increase of transcription of DNMT3B in HCAEC exposed to mitomycin C compared to the control was observed. At the same time, no changes in transcription of the studied DNA-methyltransferases were found in HITAEC exposed to the mutagen. Thus, increased transcription of DNA-methyltransferase may be a possible molecular mechanism underlying endothelial dysfunction in response to mutagenic load in an in vitro experiment.

[The gene expression signature in endothelial cells exposed to mitomycin C]

The expression of DNA repair (DDB1, ERCC4, ERCC5), leukocyte adhesion (VCAM1, ICAM1, SELE, SELP), endothelial mechanotransduction (KLF4), endothelial differentiation (PECAM1, CDH5, CD34, NOS3), endothelial-to-mesenchymal transition (SNAI1, SNAI2, TWIST1, GATA4, ZEB1, CDH2), scavenger receptors (LOX1, SCARF1, CD36, LDLR, VLDR), antioxidant system (PXDN, CAT, SOD1) and transcription factor (HEY2) genes in primary human coronary (HCAEC) and internal thoracic (HITAEC) arteries endothelial cells exposed to alkylating mutagen mitomycin C (MMC) was studied at two time points - after 6 h of incubation with MMC and after 6 h of the genotoxic load followed by 24 h of incubation in pure culture medium using the quantitative PCR. Immediately after MMC exposure, in the exposed HCAEC and HITAEC a decreased expression of almost all studied genes was noted excepted SNAI, which demonstrated a 4-told increase in its expression compared to the unexposed control. Elimination of MMC from the cultures, an increased expression of the VCAM1, ICAM1, SELE, SNAI2, KLF4 genes and a decreased the mRNA level of the PECAM1, CDH5, CD34, ZEB1, CAT, PXDN genes were observed in both cell lines. In addition, HITAEC cells were characterized by a decreased expression of the SOD1, SCARF1, CD36 genes and an increased expression of the SNAI1 and TWIST1 genes; in HCAEC, an increased mRNA level of the LDLR and VLDLR genes was noted. Thus, MMC-induced genotoxic stress is associated with the endothelial dysfunction.

[The expression level of cytokine genes in the cases of native heart valves in infectious endocarditis]

The expression level of IL1B, IL6, IL8, IL10, IL12A, IL12B, IL18, IL23, IL33, CCL2, and IL1RL1 has been investigated using biopsies of native mitral, aortic, and tricuspid valves obtained during surgical correction of acquired defect from 25 patients with infectious endocarditis. Biopsies of native mitral and aortic valve cusps from 12 patients who underwent surgical correction of acquired heart disease of non-infectious etiology were used as control. We used quantitative PCR with fluorescent dye SYBR Green for determination of the cytokine gene expression level. This study revealed that genes could be subdivided into three groups: (i) genes with increased expression (IL1B, IL6, and IL8); (ii) genes with reduced expression (IL33 and IL1RL1); (iii) genes with unchanged expression (IL12A, IL18, IL23, and CCL2). The IL8 gene expression was characterized by the most pronounced increase (9.83 times versus control), while the IL1RL1 gene demonstrated the most pronounced decrease in its expression (4.17 times). Expression of IL10 and IL12B genes was negligible in all samples.

[Adiponectin gene expression in local fat depots in patients with coronary heart disease depending on the degree of coronary lesion]

AIM

To determine the dependence of adiponectin gene expression by subcutaneous, epicardial and perivascular adipocytes on the degree of coronary lesion in coronary heart disease.

MATERIALS AND METHODS

84 patients with coronary artery disease were examined. Of these, 39 people showed a moderate degree of atherosclerotic lesion of the coronary bed (less than or equal to 22 points) on the SYNTAX Score scale, 20 severe (2231 points), and 25 extremely severe (more than 32 points). Upon admission to the hospital, all patients underwent an echocardiographic study (Echocardiography, Acuson, Germany) with the calculation of the ejection fraction (EF) of the left ventricle (LV) to assess its systolic function. During a planned surgical intervention (coronary bypass surgery, CABG), adipocytes of subcutaneous, epicardial (EAT) and perivascular adipose tissue (PVAT) were taken. Adiponectin gene expression was evaluated by polymerase chain reaction (real-time PCR) using TaqMan probes. Statistical analysis was performed using Statistica 9.0.

RESULTS

The maximum level of adiponectin expression was detected in adipocytes of PVAT, and the minimum EAT. With an increase in the degree of atherosclerotic lesion of the coronary bed, the expression of the adiponectin gene in adipocytes of local depots significantly decreases r=-0.82; p=0.023. Moreover, the low level of gene expression in EAT correlated with a decrease in LV EF by r=0.73; p=0.03. In adipocytes of subcutaneous and especially PVAT, gene expression was the highest in patients with a moderate degree of coronary lesion.

CONCLUSIONS

Low adiponectin gene expression in EAT is associated with an increase in the degree of atherosclerotic lesion of the coronary bed and a decrease in LV EF.

[Expression of gene and content of adiponectin in fatty tissue in patients with ischemic heart disease]

The purpose of the study was to investigate the features of expression and adiponectin content in the adipocyte culture of subcutaneous, epicardial, and perivascular adipose tissue and the effect of various doses of rosuvastatin on these processes. 29 patients with coronary artery disease were examined. Adipocytes were isolated from the samples of SAT, EAT and PVAT which were taken during coronary artery bypass surgery, followed by cultivation in the presence of rosuvastatin and evaluation of gene expression and adiponectin concentration. Adipocytes SAT, EAT and PVAT differed in the level of adiponectin secretion and expression of its gene. On day 1 of cultivation the expression of the adiponectin gene in the EAT was 2.3 times lower than in the PVAT. On day 2 of cultivation the expression of the adiponectin gene was reduced both in the EAT and the PVAT as compared to the SAT. When rosuvastatin was added at a concentration of 1 mmol/L, adiponectin gene expression in PVAT was higher than when rosuvastatin was added at a concentration of 5 mmol/L, in the adipocyte culture of SAT effect was opposite. Thus, the adipocytes of EZhT and, to a greater extent, PAS, can be a therapeutic target for statins in the case of the pathological activation of adipose tissue.

[Microflora of peripheral blood obtained from patients with infective endocarditis.]

Infective endocarditis is a serious inflammatory disease associated with damage of heart valves and other parts of endocardium. This study included 91 patients with a confirmed diagnosis of «infectious endocarditis» and hospitalized at the Research Institute of Complex Problems of Cardiovascular Disease (Kemerovo, Russia) from 2010 to 2015. The determination of the spectrum of microorganisms in the samples of patients' peripheral blood was carried out using the PCR method using reagents produced by Lyteh Ltd. (Moscow, Russia) allowing detect Staphylococcus spp., Staphylococcus aureus, Streptococcus pyogenes, Streptococcus agalacticae, Enterobacter spp., Klebsiella spp., Proteus spp., Haemophilus influenza, Enterococcus faecalis, Enterococcus faecium in the samples of biological material. Statistical analysis was performed in the StatSoft STATISTICA 10 software. 83.5% of patients were characterized by presence Staphylococcus spp. in the peripheral blood; the other pathogens were detected much less often (from six cases of enterococci detection to one case of Streptococcus agalacticae and Proteus spp.). In nine patients, none of the analyzed pathogens was detected, and a number of patients were characterized by the simultaneous presence of several pathogens. There was no reliable data on the difference in microflora structure depending on sex, drug addiction, the type of infective endocarditis and the damaged valve. It was established that the results of PCR of peripheral blood samples and microbiological examination of the tissues of damaged valves that were removed during cardiac surgery, differ significantly. The obtained results testify to the need for more in-depth studies including PCR analysis of peripheral blood samples, flushing from damaged valves, and also homogenized valve tissue samples, which will allow us to obtain more detailed data and conclude that PCR can be used as a diagnostic test for early detection microbiological agent as causative.