REVIEWS AND LECTURES
Progress in understanding of structural and functional human genome organization and deciphering primary DNA sequence in human cells allowed for hitherto unreachable new capabilities of medical genetics in identifying the causes and mechanisms of inherited and inborn pathology. Implementation of genetics into medicine is progressively advancing along with improvement of molecular analysis of genome. Knowledge of genome and its functions allows to provide more accurate diagnosis, predict, to a considerable extent, the presence of genetic predisposition of a person to pathology, and to assess the chances for developing one or another disease. This approach became the basis for a new area of medical genetics named predictive medicine. The progress of predictive medicine refl ects success in tremendous upgrowth of molecular genetic methods and new capabilities of studying structure and functions of genome. Within less than 15 years after deciphering genome, medical genetics has travelled a long way from a single gene analysis to whole genome studies, from screening of genetic associations to systems genetics of multifactorial diseases, from translational to high-precision genetics, and from genetic passport idea to electronic genetic health records. The development of a genetic passport, prognostic genetic testing, and genomic chart of reproductive health is especially relevant for current practical medicine.
Data on the features of genetic counseling and predictive testing in patients with hereditary cardiovascular diseases are presented in the review. The ethical problems of genomic testing especially in regard to secondary (incidental) fi ndings, cascade screening, examination of children and adolescents, and postmortem genetic testing are discussed. Particular attention is paid to the psychosocial impact of genetic testing.
The present work summarizes data of recent studies related to the search for the genetic component of complex diseases leading to impaired cognitive functions. The main attention is paid to such pathologies as schizophrenia and Alzheimer’s disease. The article provides a detailed analysis of a wide range of modern genetics methods: from twin studies to epigenetic research.
Cardiogenic shock mortality did not decrease over the past decade despite the large number of studies focusing on the problem and the achieved success in the treatment of myocardial infarction. This provides rationale for search for new approaches to studying the problem in order to identify new opportunities to change the current situation. The article analyzes the experience of completed clinical trials and characterizes prospective studies on the treatment of cardiogenic shock.
CLINICAL STUDIES
Hypertension, coronary heart disease, myocardial infarction, obesity, and type 2 diabetes mellitus are common comorbidities in patients with bronchial asthma. The causes for developing these diseases are multifactorial and involve inherited genetic factors. However, little is known about the genes contributing to the development of comorbidities in bronchial asthma and cardiovascular disease continuum.
Objective. To examine the associations of genetic polymorphic variants potentially involved in the development of bronchial asthma comorbid with hypertension, coronary heart disease, type 2 diabetes mellitus, and obesity.
Material and Methods. Genotyping of 92 single nucleotide polymorphisms (SNPs) was performed using MALDI-TOF mass spectrometry in patients with bronchial asthma associated with cardiovascular/metabolic disorders (n = 162) compared with a control group of apparently healthy individuals (n = 153).
Results. The development of bronchial asthma phenotypes comorbid with cardiovascular/metabolic disorders was associated with the particular genetic variants affecting the expression of genes including CAT, TLR4, ELF5, ABTB2, UTP25, TRAF3IP3, NFKB1, LOC105377347, C1orf74, IRF6, and others in the target organs of study disease profile. Only one SNP (rs11590807), which is regulatory for the UTP25, IRF6, TRAF3IP3, and RP1-28O10.1 genes, was associated with all studied comorbid phenotypes of bronchial asthma and diseases of cardiovascular continuum.
Conclusion. The obtained results demonstrated that the identified SNPs affecting the expression of many genes may serve as potential biological markers of complex causal relationships between bronchial asthma and cardiometabolic disorders.
Aim. To study changes in the level of piRNA in plasma and serum of pregnant women at different stages of gestation.
Material and Methods. A total of 42 samples of plasma and blood serum were obtained from seven women with physiological singleton pregnancy without obstetric and gynecological pathology. The study was carried out at three time points corresponding to 8–13, 18–25, and 30–35 weeks of pregnancy, respectively. To assess the spectrum and levels of piRNA by the NGS method, whole genome sequencing of small RNAs was carried out. Sequencing data analysis was performed using the GeneGlobe Data Analysis Center web application. Differential expression was assessed using the DESeq2 R package.
Results and Discussion. The piRNA contents among all small RNAs were 2.29%, 2.61%, and 4.16% in plasma and 7.29%, 7.02%, and 10.82% in serum during the first, second, and third trimesters, respectively. The contents of the following piRNAs increased in blood plasma from the first to the third trimester: piR 000765, piR 020326, piR 019825, piR 020497, piR 015026, piR 001312, and piR 017716. The study showed that the levels of piR 000765, piR 020326, piR 019825, piR 015026, piR 020497, piR 001312, piR 017716, and piR 004153 were significantly higher in serum compared with the corresponding values in plasma whereas the content of only one molecule, piR 018849, was higher in plasma.
Conclusion. This pilot work created a basis for understanding the processes of piRNA expression in plasma and serum of pregnant women and can become the foundation for the search for biomarkers of various complications in pregnancy.
The pathogenesis of atherosclerosis and ischemic heart disease is associated with oxidative stress and mitochondrial dysfunction. Mitochondrial DNA encodes subunits of mitochondrial respiratory chain and is highly polymorphic in human populations. Mitochondrial DNA can be considered a candidate genetic locus for predisposition to cardiovascular diseases.
Aim. To analyze the associations of the mitochondrial genome polymorphism and chronic heart failure in ischemic heart disease.
Material and Methods. The study included two groups of individuals: patients with a combination of ischemic heart disease and chronic heart failure (n = 175) and a population sample of residents of Tomsk (n = 424). Percentages of patients with chronic heart failure of NYHA classes II, III, and IV were 37%, 50%, and 13%, respectively. All patients underwent echocardiographic examination; body mass index and the lipid fractions in blood serum were determined. The average was 55.4 years in patients and 47.6 years in the population sample. Polymorphism of mtDNA was studied by sequencing the hypervariable segment of D-loop of mtDNA and subsequent classification of mtDNA haplotypes into the known haplogroups. The mtDNA haplogroup frequencies were compared between the samples using the Chi-square test. The associations of genotype with quantitative trait variability were analyzed by variance analysis.
Results. Male patients showed a higher frequency of haplogroup H compared to the population (45.86% in patients and 35.4% in population) and a higher total frequency of haplogroup H subgroups except the most frequent subgroup H1 (36.94% and 25.22%, respectively). The values of significance level (p-value) and odds ratio (OR) were determined as follows: p = 0.04; odds ratio OR = 1.55 (95% confidence interval (CI) 1.02–2.34) for haplogroup H as a whole; p = 0.02; OR = 1.74 (95% CI 1.12–2.70) for haplogroup H without subgroup H1. Analysis of quantitative traits revealed the associations of the same genetic marker (mtDNA haplogroup H) with the levels of high-density lipoproteins (p = 0.03) and triglycerides (p = 0.02) in blood serum of men in the population sample.
Conclusion. The obtained results suggested that the most frequent European mtDNA haplogroup H may be a risk factor for the complications of ischemic heart disease in men.
Objective. To study β1 and β3 integrin expression in nonspecific invasive breast carcinoma and to find the associations with parameters of tumor morphological heterogeneity and lymphatic dissemination.
Material and Methods. Study group comprised 107 patients with breast cancer. Histological type of tumor corresponded to invasive carcinoma of a nonspecific type (invasive ductal carcinoma) in 100% of cases. Patients did not receive any preoperative treatment. In each case, we performed morphological examination of samples of primary tumor and axillary lymph nodes obtained at the surgical stage of treatment (radical mastectomy or sectoral resection of mammary gland with axillary lymphadenectomy). The parameters of β1 and β3 integrin expression in primary tumor tissue were assessed by immunohistochemistry.
Results. The study demonstrated that an increase in the degree of malignancy of breast carcinoma was associated with a decrease in the incidence of positive expression of β1 integrin as well as with an increase in the incidence of positive expression of β3 integrin. Metastases in lymph nodes were significantly less frequently detected in the presence of positive expression of β1 integrin in the alveolar and solid structures compared with the cases of absent expression of the marker in similar structures (48%; χ2 = 3.5; p = 0.05 and 48%; χ2 = 4.8; p = 0.02, respectively). Lymphogenic metastasis were detected significantly more often in cases with positive expression of β3 integrin in discrete groups of cells compared with the cases where the expression of study marker in the described structures was absent (47 and 23%, respectively; χ2 = 5.1; p = 0.02).
Conclusion. The results of work showed the presence of relationships between the morphological heterogeneity of the tumor and the parameters of β1 and β3 integrin expression in the parenchymal structures of the neoplasm. The study showed the association of described parameters with the frequency of lymphatic dissemination in patients with breast cancer. Obtained data expand and support previously known evidence and suggest the possibility of assessing the markers as potential prognostic factors predicting the course of cancer.
Aim. To analyze the relationships between the carriage of polymorphic variants in the folate metabolism genes and the development of thrombotic complications in patients with single ventricle (SV) during surgical treatment.
Material and Methods. A total of 102 children with SV were examined in the performed research. All patients underwent surgical hemodynamic correction of congenital heart disease (CHD). According to a retrospective chart review, thrombosis was diagnosed in 12.7 % of the examined patients with SV. The analysis of polymorphism in the MTR A2756G enzyme gene revealed significant differences between the groups of patients with a history of thrombosis and without it.
Results. We found that the risk of developing thrombosis was associated with the carriage of homozygous genotype 2756AA of the MTR enzyme gene (OR = 11.21; 95% CI: 1.39–89.96; p = 0.023).
High prevalence of bronchial asthma among the population (about 300 million people all over the world) provides rationale for the search for candidate genes of disease. Human acidic chitinase (CHIA (AMCase)), encoded by the CHIA gene, is involved in the degradation of chitin, a component of the fungal cell wall and arthropod exoskeleton, which, if present in food or house dust, is a provoking factor for the bronchial asthma (BA) development. Functionally significant mutations in the CHIA gene may apparently increase the risk of susceptibility to BA.
Aim. The aim of the study was to assess the associations of single nucleotide polymorphisms (SNPs) rs12033184 and rs3806448 in the CHIA gene with bronchial asthma in children in Novosibirsk.
Material and Methods. The study was organized as case-control. A total of 537 blood samples were used. SNPs were determined by real-time PCR. The associations of polymorphic variants with the disease were assessed by the odds ratio.
Results. No associations of rs12033184 and rs3806448 with BA were found.
Conclusion. The role of acidic chitinase gene in the development of BA in residents of Novosibirsk was found to be less significant than in the Indian population where it was previously shown to be associated with the disease.
The main features of schizophrenia are characterized by three domains of symptoms, including positive symptoms, negative symptoms, and cognitive defi cits, the overlap of which forms a polymorphism of clinical manifestations. Previous molecular genetic studies have found signifi cant genetic overlaps between the cognitive abilities and the risk of schizophrenia developing. Recent evidence suggests that oxidative stress may play an important role in the pathophysiology of schizophrenia.
Aim. The aim of the study was to investigate the associations of polymorphisms of genes encoding the antioxidant enzymes SOD2, GSTO1, and NQO1 with clinical polymorphism of schizophrenia and the severity of cognitive deficit.
Material and Methods. A comprehensive examination of 457 patients with a diagnosis of schizophrenia was carried out. Out of the total group of examined patients, cognitive functions were assessed using the BACS scale in 150 schizophrenic patients. The control group comprised 135 healthy individuals with age and gender corresponding to patient group. Their cognitive function was assessed. Genotyping of SOD2 (rs4880), GSTO1 (rs4925), and NQO1 (rs1800566) was done by realtime PCR.
Results. When analyzing the distribution of genotypes and alleles of polymorphic variants of genes encoding the antioxidant enzymes SOD2, GSTO1, and NQO1, no associations between the studied loci and schizophrenia in the Russian population of the Siberian region were revealed. Also, no associations were found with clinical polymorphism of disease (disease course type, leading symptoms (positive or negative), and age of disease onset). The cognitive abilities of schizophrenic patients and healthy individuals were diff erent as expected, but no associations with genetic characteristics were found.
Conclusion. In this work, we obtained negative results in regard to associations of polymorphic variants of genes encoding the antioxidant enzymes SOD2 (rs4880), GSTO1 (rs4925), and NQO1 (rs1800566) with the development of schizophrenia in the Russian population in the Siberian region, as well as with the severity of cognitive defi cit. The genetic profi le for the studied loci did not aff ect the clinical manifestations of disease in the examined sample.
Objective. To study the early and late outcomes of surgical treatment of patients with concomitant atherosclerotic lesions of coronary and brachiocephalic arteries while choosing a treatment strategy based on the developed diff erentiated approach algorithm.
Material and Methods. The study comprised 243 patients with combined atherosclerotic lesions of the coronary and carotid arteries examined during the period from 01.07.2014 to 01.01.2021. Patients underwent revascularization surgeries based on the algorithm for choosing the volume and stages of surgical intervention, which was previously developed in the Federal Center for Cardiovascular Surgery named after S.G. Sukhanov. A single-stage combined surgery of coronary artery bypass grafting (CABG) and carotid endarterectomy (CEE) was performed in 104 patients (42.8%); 139 patients (57.2%) received staged revascularization including 102 patients (73.4%) who received CABG as the fi rst step and 37 patients (26.6%) who received CEE as the fi rst step of surgery. The endpoints for both early and late results were death from all causes, stroke, transient ischemic attack (TIA), acute myocardial infarction (AMI), and combined endpoint that included all of the above. Average follow-up time was 41.1 ± 21.8 months.
Results. No fatal outcomes were in any group during the early postoperative period. At the hospital stage, there were 5 cases (2.1%) of stroke, 1 case (0.4%) of TIA, and 3 cases (1.2%) of acute MI. Long-term results were evaluated in 225 patients (92.3%). The overall survival rate was 93.8%. There were 5 cases (2.4%) of MI, 11 cases (4.9%) of stroke, and 1 case (1.0%) of TIA. No signifi cant diff erences were observed in immediate and long-term endpoints between the groups of staged and combined interventions as compared to immediate (AMI: p = 0.680; TIA: p = 0.500; acute cerebrovascular events: p = 0.567; combined: p = 0.940) and long-term results (deaths: 0.860; AMI: p = 0.906; TIA: p = 0.528; acute cerebrovascular events: p = 0.378; combined: p = 0.669).
Conclusion. Based on successful experience with treating the concomitant atherosclerotic lesions of the coronary and brachiocephalic arteries, the proposed algorithm allowed to perform safe procedures in both arterial basins and to achieve satisfactory results in in-hospital and long-term periods in the Federal Center for Cardiovascular Surgery named after S.G. Sukhanov (Perm).
The article presents our own experience of organoprotection during thoracic aortic surgery under circulatory arrest and off ers our own concept for perfusion of organs during surgical interventions for aortic dissection and thoracic aortic aneurysms.
EXPERIMENTAL STUDIES
Xenobiotic metabolism system in the current populations is involved in the biotransformation of a wide range of endogenous substrates and various xenobiotics, which can contribute to developing the diseases of various organ systems, and, in some cases, comorbid conditions where increased biotransformation system activity is observed. In this regard, it is of great interest to study the involvement of polymorphism in xenobiotic metabolism genes in the development of both isolated pathology and various comorbid conditions.
Aim. The goal of study was to investigate the involvement of rs4244285 in the CYP2C19 gene in the development of isolated pathology and comorbidities.
Material and Methods. The frequencies of alleles and genotypes were studied in groups of patients with comorbid conditions including groups of coronary artery disease (CAD) with hypertension (HTN) (CAD_HTN, n = 133) and bronchial asthma (BA) with HTN (BA_HTN, n = 178), in group of isolated BA (n = 135), and in the population sample of the city of Tomsk (n = 377). Association analysis covered three initial groups of patients (CAD, BA, and BA_HTN) and subgroups assigned based on the presence of absence of HTN diagnosis taking into account comorbid conditions both in patient samples and in population control.
Results and Discussion. The study demonstrated the predisposing eff ect of GA genotype on the development of comorbid BA and HTN (OR = 1.94, p = 0.038) and comorbid CAD and HTN (OR = 2.26, p = 0.009) compared to isolated BA. The AA genotype was observed 3.98 times less often in HTN patients than in normotensive individuals. However, the diff erences did not reach the level of statistical signifi cance due to the low occurrence of this genotype.
Conclusion. The obtained results may be explained by the involvement of CYP2C19-metabolites of arachidonic acid in the regulation of vascular tone, which requires further study.
The identification of new SARS-CoV-2 and human protein and gene targets, which may be markers of the severity and outcome of the disease, are extremely important during the COVID-19 pandemic. The goal of this study was to carry out genetic analysis of SARS-CoV-2 RNA samples to elucidate correlations of genetic parameters (SNPs) with clinical data and severity of COVID-19 infection.
Material and Methods. The study included viral RNA samples isolated from 56 patients with COVID-19 infection who received treatment at the City Hospital No. 40 of St. Petersburg from 04/18/2020 to 04/18/2021. Patients underwent physical examination with the assessments of hemodynamic and respiratory parameters, clinical risk according to National Early Warning Score (NEWS), computed tomography (CT) of the chest, and laboratory studies including clinical blood analysis, assessment of ferritin, C-reactive protein (CRP), interleukin-6 (IL-6), lactate dehydrogenase (LDH), D-dimer, creatinine, and glucose levels. All patients tested positive for SARS-CoV-2 RNA by polymerase chain reaction (PCR). Single nucleotide polymorphisms (SNPs) in viral RNA were identified through the creation of cDNA libraries by targeted sequencing (MiSeq Illumina). Bioinformatic analysis of viral samples was performed using the viralrecon v2 pipeline with the further annotation via Pangolin and Nextlade. Sampled genomes were visualized using the Integrative Genomics Viewer (IGV) software. Statistical data processing (descriptive statistics and graphical analysis of data relationships from diff erent tables) was performed using a GraphPad device on the Prism 8.01 platform.
Results. A comparative analysis of SNP frequencies in the virus genome in samples from deceased and discharged patients was carried out. The SNPs associated with risk of death (OR > 1), neutral SNPs (OR = 1), and protective SNPs (OR < 1) were identifi ed. Patient samples were infected with 14 lines of SARS-CoV-2, fi ve of which (B.1.1.129, B.1.1.407, B.1.1.373, B.1.1.397, and B.1.1.152) were of Russian origin. The SNPs in the samples infected with the strains of non-Russian origin were associated with an increased risk of mortality (OR = 2.267, 95% confi dence interval 0.1594-8.653) compared to the SNPs in the samples obtained from the group of patients infected with the strains of Russian origin. Positive correlations were identifi ed between the average SNP number, nonsynonymous SNPs, and S-protein SNPs with the degree of respiratory failure, total NEWS score, CT-based form of disease, duration of treatment with mechanical ventilation, disease outcome, levels of LDH, glucose, D-dimer, and ferritin, and RNA amount in the PCR test. S-protein SNPs negatively correlated with the leukocyte and neutrophil counts.
Objective. To study the molecular mechanisms responsible for the development of diseases grouped within the great obstetrical syndromes (GOS) at the level of the transcriptome of human maternal placenta.
Material and Methods. We gathered the results of genome-wide transcriptome studies of the human placental tissue using Gene Expression Omnibus (GEO) data repository for the following phenotypes: physiological pregnancy, preeclampsia (PE), premature birth, and intrauterine growth restriction (IUGR). Eleven data sets were selected and supplemented with our experimental data; a total of 481 samples of human placental tissue were included in the integrative analysis. Bioinformatic data processing and statistical analyses were performed in the R v3.6.1 software environment using the Bioconductor packages. The pooled dataset was used to search for common molecular targets for GOS via weighted gene co-expression network analysis (WGCNA). The functional annotation of genes and the resulting clusters was carried out with the DAVID database; protein-protein interaction network was built using the STRING software; and the hub genes for the network were identified using the MCC analysis with plugin cytoHubba in Cytoscape software 3.7.2.
Results. We obtained a table of expression levels for 15,167 genes in 246 samples. Hierarchical clustering of this network allowed to find 55 modules of co-expressed genes in the group with PE, 109 modules in the group with PB, 75 modules in patients with IUGR, and 56 modules in the control group. The preservation analysis of co-expressed modules for the studied phenotypes suggested the presence of a common cluster comprising eight genes specific only for patients with PE and IUGR, as well as the module of 23 co-expressed genes typical only for patients with PB and IUGR. Protein-protein interaction network was built for these gene sets, and the SOD1, TXNRD1, and UBB genes were the central nodes in the network. Based on network topology evaluation with cytoHubba, six hub genes (rank ˂ 5) were identified as follows: SOD1, TKT, TXNRD1, GCLM, GOT1, and ACO1.
Conclusion. The obtained results allowed to identify promising genetic markers for preeclampsia, intrauterine growth restriction, and miscarriage. Moreover, the study also made it possible to identify the most important overlapping molecular mechanisms of these diseases occurring in the placental tissue.
Aim. The goal of the study was to analyze the differential expression of lipid metabolism-related genes in the atherosclerotic plaques of different types in patients with coronary atherosclerosis.
Material and Methods. The study was performed on the specimens of atherosclerotic plaques in 45–65-year-old patients with coronary atherosclerosis with stable exertional angina functional class II-IV without acute coronary syndrome. Coronary atherosclerosis was verified by coronary angiography. Atherosclerotic plaque tissue was sampled intraoperatively when indicated. Whole-genome sequencing of ribonucleic acid (RNA) was performed using the TruSeq RNA Sample Preparation Kit (Illumina, USA).
Results. We analyzed the differences in the expression of 12 genes including LDLR, APOB, PCSK9, LDLRAP1, LIPA, STAP1, ABCA1, APOA1, APOE, LPL, SCARB1, and SREBF2 depending on the type of atherosclerotic plaques. The expression level of APOE gene was eight times higher in unstable atherosclerotic plaques of dystrophic-necrotic type (p < 0.0001). The expression levels of LDLR and APOB genes were eight times higher in stable atherosclerotic plaques (p < 0.0001). We did not find differences in the expression levels of the ABCG5, ABCG8, APOC3, CETP, CLPS, CYP7A1, and PNPLA5 genes.
Conclusion. The study showed the differences in the activity of individual metabolism-related genes in the atherosclerotic plaques of different types in patients with coronary atherosclerosis. Obtained data may become the basis for the development of test systems aimed at predicting the development of atherosclerotic process and its complications.
CLINICAL CASES
Anthracycline antibiotics are an important group of widely used and highly eff ective antitumor drugs. However, the cardiotoxicity of anthracyclines included in the polychemotherapy regimens results in the development of cardiovascular diseases both in the early and late rehabilitation period. The article presents a clinical case demonstrating the long-term consequences of highdose polychemotherapy with the onset of heart failure and coronary artery disease.
IN MEMORY OF COLLEAGUE
ISSN 2713-265X (Online)