The structure of the haplotypes and linkage disequilibrium (LD) of the methylenetetrahydrofolate reductase gene (MTHFR) in 9 population groups from Northern Eurasia and populations of the international HapMap project was investigated in the present study. The data suggest that the architecture of LD in the human genome is largely determined by the evolutionary history of populations; however, the results of phylogenetic and haplotype analyses seems to suggest that in fact there may be a common “old” mechanism for the formation of certain patterns of LD. Variability in the structure of LD and the level of diversity of MTHFR haplotypes cause a certain set of tagSNPs with an established prognostic significance for each population. In our opinion, the results obtained in the present study are of considerable interest for understanding multiple genetic phenomena: namely, the association of interpopulation differences in the patterns of LD with structures possessing a genetic susceptibility to complex diseases, and the functional significance of the pleiotropic MTHFR gene effect. Summarizing the results of this study, a conclusion can be made that the genetic variability analysis with emphasis on the structure of LD in human populations is a powerful tool that can make a significant contribution to such areas of biomedical science as human evolutionary biology, functional genomics, genetics of complex diseases, and pharmacogenomics.

Исследована структура гаплотипов и неравновесия по сцеплению (LD) в локусе метилентетрагидрофолатредуктазы (MTHFR) в девяти этнотерриториальных выборках Северной Евразии и популяциях из международного проекта HapMap. Полученные данные свидетельствуют о том, что архитектура LD в геноме человека в значительной степени определяется эволюционной историей популяций, тем не менее, результаты гаплотипического и филогенетического анализа указывают на возможность существования общего, «древнего» механизма формирования некоторых паттернов LD. Вариабельность структуры LD и уровень гаплотипического разнообразия гена MTHFR в исследованных выборках обуславливают определенный набор tagSNPs (tagging single nucleotide polymorphisms; полиморфизмы, аллельные варианты которых маркируют гаплотипические блоки) с установленной прогностической значимостью для каждой популяции. Полученные в настоящей работе данные представляют, по нашему мнению, значительный интерес в понимании нескольких генетических феноменов: ассоциации межпопуляционных различий в характере LD со структурой наследственной предрасположенности к многофакторным заболеваниям; функциональной значимости и плейотропного «поля действия» гена MTHFR. Суммируя результаты проведенного исследования, можно заключить, что анализ генетической вариабельности с акцентом на структуру LD в популяциях человека является мощным инструментом, способным внести большой вклад в такие отрасли медико-биологической науки, как эволюционная биология человека, функциональная геномика, генетика многофакторных заболеваний и фармакогеномика.

In this study, we genotyped polymorphism in GPX1 Pro198→Leu (C→T) rs 1050450 in four groups, i.e., patients with coronary artery disease, people who lived a long time (over 90 years), people who died early (before 55 years) from cardiovascular disease, and the Russian population as a control group. We have found a significant higher T-allele frequency in men with coronary artery disease, i.e., 34.84% (χ2 = 5.228, p = 0.022; OR =1.46), and in men who died early from cardiovascular diseases, 38.16% (χ2 = 6.461, p = 0.011; OR = 1.69) compared to men in the control group, 26.8%. Moreover, a significantly higher genotype TT frequency has been shown in patients with coronary artery disease and myocardial infarction before age 50, which is 19.44% compared to the control group, which was 7.28% (χ2 = 9.55, p = 0.002). The TT frequency in individuals who lived a long time (4.39%) was the lowest and differed significantly from the group with coronary artery disease, which was 12.79% (χ2 = 8.07, p = 0.0045), and from the subgroup with coronary artery disease with myocardial infarction before age 50, which was 19.44% (χ2 = 14.49, p = 0.0001). Thus, our results indicate that the TT allele (Leu) of GPX1 Pro198→Leu (C > T) polymorphism is unfavorable for successful aging; it leads to predisposition to coronary artery disease, early myocardial infarction (before age 50), and early death (before age 55).

Изучено распределение генотипов и аллелей полиморфного варианта гена GPX1 (rs 1050450) (С), обусловливающего замену Pro198 Leu в глутатионпероксидазе, в нескольких выборках, включающих долгожителей, больных ишемической болезнью сердца, лиц, умерших до 55 лет, а также в контрольной популяционной выборке жителей г. Томска. Показано, что частота аллеля Т статистически значимо выше у мужчин, больных ишемической болезнью сердца –34.84% ( 2 = 5.228 р = 0.022, OR = 1.46), и мужчин, умерших до 55 лет от сердечно-сосудистых заболеваний –38.16% ( 2 = 6.461 р = 0.011, OR = 1.69), по сравнению со здоровыми мужчинами –26.8%. Кроме того, обнаружена более высокая частота генотипа ТТ в группе больных ишемической болезнью сердца, перенесших инфаркт миокарда до 50 лет –19.44% по сравнению с популяционной выборкой жителей г. Томска –7.28% ( 2 = 9.55, p = 0.002). Частота генотипа TT у долгожителей (4.39%) статистически значимо отличается от частоты этого генотипа в группе больных ишемической болезнью сердца –12.79% ( 2 = 8.07, p = 0.0045) и в подгруппе больных ишемической болезнью сердца с инфарктом миокарда до 50 лет –19.44% ( 2 = 14.49, p = 0.0001). Эти результаты указывают на то, что аллель Т полиморфизма Pro198 Leu (C > T) гена GPX1, соответствующий аминокислоте лейцину в этой позиции, дает неблагоприятный прогноз, указывающий на предрасположенность к развитию ишемической болезни сердца, более раннему инфаркту миокарда и ранней смерти.

Genomic imprinting is one of the key epigenetic phenomena involved in embryonic development of eutherians and humans. Molecular mechanisms of imprinting disturbances in the pathology of prenatal and postnatal onthogenesis are to a great extent related to methylation abnormalities of the imprinted genes. Over recent years, data are accumulating on multiple abnormalities of methylation simultaneously in several imprinted loci in the development of various pathologies that raises the issue of deciphering the structural and functional organization of imprintome and the interaction of imprinted genes. The present work analyzes DNA methylation of 51 imprinted genes in the placental tissues of human spontaneous abortions. We revealed multiple epimutations in from four to 12 imprinted genes in every embryo. Most of the epimutations (78%) were of a postzygotic origin. It has been established for the first time that the total incidence of methylation disturbance in maternal and paternal alleles of the imprinted genes leading to embryo development suppression is significantly higher than the incidence of epimutations, which stimulate embryogenesis. This fact supports at the epigenetic level the hypothesis of parent-offspring conflict that describes the occurrence of a monoallelic expression of imprinted genes in mammalian evolution.

Геномный импринтинг – один из ключевых эпигенетических феноменов, вовлеченных в обеспечение эмбрионального развития плацентарных млекопитающих и человека. Молекулярные механизмы нарушений импринтинга при патологии пре- и постнатального онтогенеза в значительной степени связаны с аномалиями дифференциального метилирования импринтированных генов. В последнее время накапливаются данные о множественных нарушениях характера метилирования одновременно в нескольких импринтированных локусах при различных патологических состояниях, что поднимает проблему расшифровки структурно-функциональной организации импринтома и взаимодействия генов, подверженных импринтингу. В представленной работе проведен анализ характера метилирования ДНК 51 импринтированного гена в плацентарных тканях эмбрионов человека с остановкой внутриутробного развития. У каждого эмбриона выявлены множественные эпимутации, затрагивающие от четырех до 12 импринтированных генов. Большинство эпимутаций (78%) имели постзиготическое происхождение. Впервые установлено, что суммарная частота аномалий метилирования материнских и отцовских аллелей импринтированных генов, ведущих к подавлению развития зародыша, статистически значимо превышает частоту эпимутаций, потенциально стимулирующих процессы эмбриогенеза. Этот факт поддерживает на эпигенетическом уровне гипотезу “конфликта полов”, объясняющую появление импринтированной моноаллельной экспрессии генов в эволюции млекопитающих.

The first estimation of the heterozygous carrier rates for the SMN1 gene deletions and SMN2 gene duplications in populations of Russia has been performed. The numbers of SMN gene copies have been deter-mined in samples from Chuvash and Udmurt populations, as well the population of the Moscow region, by means of multiplex ligation-dependent probe amplification. The heterozygous carrier rates for the CMA gene were 2.7% (1: 37 people), 2.8% (1: 36 people), and 2.8% (1: 36 people) in Chuvashes, Udmurts, and residents of the Moscow region, respectively. The SMN2 duplication frequencies have been determined in the studied groups. It is 1.5, 4, and 2.5% in Chuvashes, Udmurts, and residents of the Moscow region, respectively. The high SMN2 duplication frequency in Udmurts may explain why the SMN1 heterozygous carriage frequency in this population was overestimated in earlier PCR-RFLP analyses.

В настоящем исследовании впервые в России проведена оценка частоты гетерозиготного носительства делеций гена SMN1 и дупликаций гена SMN2 в популяциях чувашей, удмуртов и жителей Московского региона методом количественного анализа числа копий генов SMN на основе мультиплексной лигазной реакции с последующей амплификацией. Чaстота гетерозиготного носительства гена СМА составила 2.7% (1 на 37 человек), 2.8% (1 на 36 человек) и 2.8% (1 на 36 человек) для чувашей, удмуртов и жителей Московского региона соответственно. Установлена частота носительства дупликаций гена SMN2 в исследуемых группах. Она составила 1.5% для чувашей, 4% для удмуртов и 2.5% для жителей Московского региона. Выявленная высокая частота дупликаций гена SMN2 среди удмуртов позволяет объяснить гипердиагностику гетерозиготного носительства гена SMN1 в данной популяции в ранних исследованиях, проводившихся методом ПЦР-ПДРФ-анализа.

Aim: To assess the frequency and spectrum of chromosome aberrations and micronuclei in peripheral blood lymphocytes of patients with parotid salivary gland tumors and relapse of breast cancer during the course of neutron therapy.

Materials and methods: Samples of peripheral blood were obtained from 9 patients with parotid salivary gland tumors (T3N0-3M0) and 8 patients with relapse of breast cancer before, after first fraction and at the end of neutron therapy. The treatment course specified 5.5-8.4 Gy (equivalent to 23-44 Gy of photon irradiation) with 1.3-2.2 Gy per fraction for patients with parotid salivary gland tumors and 4,8-8.0 Gy (equivalent to 30-40 Gy of photon irradiation) with 1.6 Gy per fraction for patients with relapse of breast cancer. Control group established for conventional cytogenetic analysis consisted of 15 healthy persons. Assessment of chromosome aberrations frequency was performed on routinely stained metaphase plates. Lymphocytes from the same patients were analyzed by micronucleus test in combination with fluorescent in situ hybridization (FISH) using pancentromeric DNA probe.

Results: Level of chromosome aberrations and micronuclei significantly increased in lymphocytes of patients from both groups during neutron therapy (P < 0.05). This increase was mainly due to chromosome-type aberrations and centromere-negative micronuclei. The prevalent types of aberrations are in agreement with theoretical mechanisms of neutron effects on cells.

Conclusion: Cytogenetic effects of fast neutron therapy in lymphocytes of patients with parotid salivary gland tumors and relapse of breast cancer were observed. A positive dynamics of radiation-induced chromosomal damages formation during the course was denoted in lymphocytes of cancer patients in both groups.

In the present study we have investigated the association of three single nucleotide polymorphisms in glutathione peroxidase (GPx) genes GPX1 rs1050450 (P198L), GPX3 rs2070593 (G930A) and GPX4 rs713041 (T718C) with the risk of cerebral stroke (CS) in patients with essential hypertension (EH). A total of 667 unrelated EH patients of Russian origin, including 306 hypertensives (the EH-CS group) who suffered from CS and 361 people (the EH-CS group) who did not have cerebrovascular accidents, were enrolled in the study. The variant allele 718C of the GPX4 gene was found to be significantly associated with an increased risk of CS in hypertensive patients (odds ratio (OR) 1.53, 95% confidence interval (CI) 1.23-1.90, P(adj) = 0.0003). The prevalence of the 718TC and 718CC genotypes of the GPX4 gene was higher in the EH-CS group than the EH-alone group (OR = 2.12, 95%CI 1.42-3.16, P(adj) = 0.0018). The association of the variant GPX4 genotypes with the increased risk of CS in hypertensives remained statistically significant after adjusting for confounding variables such as sex, body mass index (BMI), blood pressure and antihypertensive medication use (OR = 2.18, 95%CI 1.46-3.27, P = 0.0015). Multiple logistic regression analysis did not reveal any interaction between various combinations of GPX1, GPX3 and GPX4 genotypes regarding the risk of CS in patients with EH. The study demonstrated for the first time that the C718T polymorphism in the 3'-untranslated region of the GPX4 gene could be considered as a genetic marker of susceptibility to CS in patients with EH.

Gene expression profiling could assist in revealing biomarkers of lung cancer prognosis and progression. The handling of biological samples may strongly influence global gene expression, a fact that has not been addressed in many studies. We sought to investigate the changes in gene expression that may occur as a result of sample processing time and conditions. Using Illumina Human WG-6 arrays, we quantified gene expression in lung carcinoma samples from six patients obtained at chest opening before and immediately after lung resection with storage in RNAlater [T1a((CO)) and T1b((LR))], after receipt of the sample for histopathology, placed in RNAlater [T2a((HP))]; snap frozen [T2b((HP.SF))]; or snap frozen and stored for 1 week [T2c((HP.SFA))], as well as formalin-fixed, paraffin-embedded (FFPE) block samples. Sampling immediately after resection closely represented the tissue obtained in situ, with only 1% of genes differing more than twofold [T1a((CO)) versus T1b((LR))]. Delaying tissue harvest for an average of 30 minutes from the operating theater had a significant impact on gene expression, with approximately 25% of genes differing between T1a((CO)) and T2a((HP)). Many genes previously identified as lung cancer biomarkers were altered during this period. Examination of FFPE specimens showed minimal correlation with fresh samples. This study shows that tissue collection immediately after lung resection with conservation in RNAlater is an optimal strategy for gene expression profiling.

Dyskinesias are involuntary muscle movements that occur spontaneously in Huntington's disease (HD) and after long-term treatments for Parkinson's disease (levodopa-induced dyskinesia; LID) or for schizophrenia (tardive dyskinesia, TD). Previous studies suggested that dyskinesias in these three conditions originate from different neuronal pathways that converge on overstimulation of the motor cortex. We hypothesized that the same variants of the N-methyl-D-aspartate receptor gene that were previously associated with the age of dyskinesia onset in HD were also associated with the vulnerability for TD and not LID. Genotyping patients with LID and TD revealed, however, that these two variants were dose-dependently associated with susceptibility to LID, but not TD. This suggested that LID, TD and HD might arise from the same neuronal pathways, but TD results from a different mechanism.

Background: Bronchodilators are drugs of choice in the combined therapy of bronchial asthma and chronic obstructive pulmonary disease (COPD). However, the therapeutic sensitivity is variable between patients, probably because of structural features of regulating molecules or variation in key genes' expression.

Objectives: The aim of this study was to evaluate the β2-adrenoceptor (ADRB2) and M3-cholinoreceptor (CHRM3) gene expression in bronchial mucosa in patients with COPD and different severity of asthma.

Methods: Biopsy specimens of right middle lobar bronchus were obtained from 59 asthma patients (10 patients with severe brittle phenotype, 14 patients with severe asthma with persistent airflow limitation, 27 patients with moderate asthma, and 8 patients with mild asthma) and 10 COPD patients with or without bronchial hyperresponsiveness (BHR). The messenger RNA (mRNA) levels for the ADRB2 and CHRM3 genes in bronchial mucosa were revealed using quantitative reverse transcription polymerase chain reaction (RT-PCR) and compared between groups.

Results: An increase of the ADRB2 genes expression was demonstrated in patients with severe asthma and COPD as compared with patients with mild and moderate disease. Significantly higher levels of ADRB2 mRNA were observed in patients with severe asthma with persistent airflow limitation. Significantly lower levels of the CHRM3 mRNA were observed in patients with COPD as compared with asthma patients. Also, CHRM3 gene expression was significantly elevated in COPD patients with BHR as compared with patients without BHR.

Conclusions: The results of the study suggest that the differential expression of the ADRB2 and CHRM3 genes is associated with asthma and COPD clinical subtypes.

В исследование были включены 82 пациента с муковисцидозом (МВ). В настоящее время во всем мире ведется активный поиск генов, оказывающих влияние на клинические проявления МВ. В работе выполнялся поиск ассоциации полиморфизмов гена IL1B, IL1RN с МВ, вариантами клинического течения и осложнениями заболевания с помощью метода «случай контроль». В результате выявлена ассоциация МВ с полиморфизмом VNTR гена IL1RN (аллель A2). Пациенты с генотипом A1A1 VNTR полиморфизма гена IL1RN имели достоверно более высокие значения ИЛ-1β.