Mutations of mtDNA, due to their higher frequency of occurrence compared to nuclear DNA mutations, are the most promising biomarkers for assessing predisposition of the occurrence and development of atherogenesis. The aim of the present article was an analysis of correlation of several mitochondrial genome mutations with carotid atherosclerosis. Leukocytes from blood of study participants from Moscow polyclinics were used as research material. The sample size was 700 people. The sample members were diagnosed with “atherosclerosis” on the basis of ultrasonographic examination and biochemical and molecular cell tests. DNA was isolated from blood leukocyte samples of the study participants. PCR fragments of DNA, containing the region of 11 investigated mutations, were pyrosequenced. The heteroplasmy level of these mutations was detected. Statistical analysis of the obtained results was performed using the software package SPSS 22.0. According to the obtained results, an association of mutations m.652delG, m.3336C>T, m.12315G>A, m.14459G>A m.15059G>A with carotid atherosclerosis was found. These mutations can be biomarkers for assessing predisposition to this disease. Additionally, two single nucleotide substitutions (m.13513G>A and m.14846G>A), negatively correlating with atherosclerotic lesions, were detected. These mutations may be potential candidates for gene therapy of atherosclerosis and its risk factors.

Objective. The aim of the present study was an analysis of heteroplasmy level in mitochondrial mutations 652delG, A1555G, C3256T, T3336C, 652insG, C5178A, G12315A, G13513A, G14459A, G14846A, and G15059A in normal and affected by atherosclerosis segments of morphologically mapped aortic walls. Methods. We investigated the 265 normal and atherosclerotic tissue sections of 5 human aortas. Intima of every aorta was divided according to morphological characteristics into segments with different types of atherosclerotic lesions: fibrous plaque, lipofibrous plaque, primary atherosclerotic lesion (fatty streak and fatty infiltration), and normal intima from human aorta. PCR-fragments were analyzed by a new original method developed in our laboratory on the basis of pyrosequence technology. Results. According to the obtained data, mutations G12315A and G14459A are significantly associated with total and primary atherosclerotic lesions of intimal segments and lipofibrous plaques (P ≤ 0.01 and P ≤ 0.05, accordingly). Mutation C5178A is significantly associated with fibrous plaques and total atherosclerotic lesions (P ≤ 0.01). A1555G mutation shows an antiatherosclerotic effect in primary lesion in lipofibrous plaques (P ≤ 0.05). Meanwhile, G14846A mutation is antiatherogenic for lipofibrous plaques (P ≤ 0.05). Conclusion. Therefore, mutations C5178A, G14459A, G12315A, A1555G, and G14846A were found to be associated with atherosclerotic lesions.

How to cite this article: Sazonova MA, Ryzhkova AI, Sinyov VV, Galitsyna EV, Orekhova VA, Melnichenko AA, Orekhov AN, Ravani AL, Sobenin IA. New markers of atherosclerosis: a threshold level of heteroplasmy in mtDNA mutations. Vessel Plus 2017;1:182-91. Aim:The aim of the present article was the detection of threshold heteroplasmy level of mitochondrial DNA mutations, above which a patient is at increased risk of atherosclerotic lesions. Besides, this parameter was detected for mutations, in which after reaching threshold heteroplasmy level, a protective antiatherogenic effect started to appear. Methods: The participants of the study were 700 women and men from the Moscow region. Fragments of DNA, amplified by polymerase chain reaction, were analyzed with pyrosequencing technology. Then on the basis of pyrograms' peaks in the samples, the heteroplasmy level of the investigated mitochondrial genome mutations was detected. Results: The threshold heteroplasmy level of 11 investigated mutations (m.5178C>A, m.15059G>A, m.652delG, m.13513G>A, m.14846G>A, m.652insG, m.12315G>A, m.3336T>C, m.1555A>G, m.14459G>A, m.3256C>T) in individuals with atherosclerotic plaques or thickening of the intima-medial layer of carotid arteries was detected. Conclusion: Using the method developed in our laboratory, the authors managed to determine threshold heteroplasmy levels of 11 mitochondrial genome mutations associated

There are several types of mitochondrial cytopathies, which cause a set of disorders, arise as a result of mitochondria’s failure. Mitochondria’s functional disruption leads to development of physical, growing and cognitive disabilities and includes multiple organ pathologies, essentially disturbing the nervous and muscular systems. The origins of mitochondrial cytopathies are mutations in genes of nuclear DNA encoding mitochondrial proteins or in mitochondrial DNA. Nowadays, numerous mtDNA mutations significant to the appearance and progress of pathologies in humans are detected. In this mini-review, we accent on the mitochondrial cytopathies related to mutations of mtDNA. As well known, there are definite set of symptoms of mitochondrial cytopathies distinguishing or similar for different syndromes. The present article contains data about mutations linked with cytopathies that facilitate diagnosis of different syndromes by using genetic analysis methods. In addition, for every individual, more effective therapeutic approach could be developed after wide-range mutant background analysis of mitochondrial genome.

How to cite this article: Sinyov VV, Sazonova MA, Ryzhkova AI, Galitsyna EV, Melnichenko AA, Postnov AY, Orekhov AN, Grechko AV, Sobenin IA. Potential use of buccal epithelium for genetic diagnosis of atherosclerosis using mtDNA mutations. Vessel Plus 2017;1:145-50. Aim:The aim of this pilot study was to compare the heteroplasmy levels of specific mitochondrial (mt)DNA mutations in human buccal epithelial and whole blood cells in participants with different degrees of predisposition to atherosclerosis. The potential for buccal epithelium to be used for the genetic diagnosis of atherosclerosis using mtDNA mutations was assessed. Methods: Samples of buccal epithelial and whole blood cells were obtained from 134 donors. DNA was extracted from the samples and subjected to polymerase chain reaction and pyrosequencing. The threshold heteroplasmy levels of the mutations m.12315G>A, m.3336T>C, m.1555А>G, m.13513G>A, and m.3256C>T were analyzed in order to assess the potential for using buccal epithelium and whole blood for the genetic diagnosis of atherosclerosis. Results: The threshold heteroplasmy levels of the assessed mitochondrial mutations did not significantly differ between buccal epithelial and whole blood cells. Conclusion: Buccal epithelial cells may be preferable to whole blood cells for analyzing the association of mitochondrial genome mutations with atherosclerosis. Key words:Buccal cell, mutation, mtDNA, threshold heteroplasmy level, mitochondrial genome, atherosclerosis ABSTRACT Article history:

Atherosclerosis is a complex disease which can be described as an excessive fibrofatty, proliferative, inflammatory response to damage to the artery wall involving several cell types such as smooth muscle cells, monocyte-derived macrophages, lymphocytes, dendritic cells and platelets. On the other hand, atherosclerosis is a typical age-related degenerative pathology, which is characterized by signs of cell senescence in the arterial wall including reduced cell proliferation, irreversible growth arrest and apoptosis, increased DNA damage, the presence of epigenetic modifications, shortening of telomere length and mitochondrial dysfunction. The most prominent characteristics of mitochondrial aging are their structural alterations and mitochondrial DNA damage. The mechanisms of mitochondrial genome damage in the development of chronic age-related diseases such as atherosclerosis are not yet well understood. This review focuses on the latest findings from studies of those mutations of the mitochondrial genome which may play an important role in the development of atherosclerosis and which are, at the same time, also markers of mitochondrial aging and cell senescence.

Atherosclerosis, the primary cause of cardiovascular disease, is a complex and multifactorial pathology resulted from the harmful interactions between genetic and environmental factors. There is a growing body of evidence in support of the role of mitochondrial factors in the pathogenesis of atherosclerosis. Impaired mitochondrial function and structural and qualitative changes in mitochondrial components such as mitochondrial DNA (mtDNA) damage may be directly involved in the development of multiple mechanisms of atherogenesis. Recent findings show that several heteroplasmic mutations of mtDNA are related to atherosclerosis, coronary heart disease and several atherosclerosis-related diseases such as arterial hypertension and diabetes mellitus. Therefore, heteroplasmic mtDNA mutations could represent a promising molecular biomarker of genetic susceptibility to atherosclerosis and related pathologies. This review is focused on the latest findings in the studies of mutations of mitochondrial genome, which are associated with atherosclerosis and atherosclerosis- related diseases.

Myocardial infarction is one of the clinical manifestations of coronary heart disease. In some cases, the cause of myocardial infarction may be atherosclerotic plaques which occurred in the human aorta. The association of mtDNA mutations with atherosclerotic lesions in human arteries was previously detected by our research group. In this study, we used samples of white blood cells collected from 225 patients with myocardial infarction and 239 control persons with no health complaints. DNA was isolated from the blood leukocyte samples. Then, PCR fragments of DNA were obtained. They contained the investigated regions of 11 mitochondrial genome mutations (m.5178C>A, m.3336T>C, m.652delG, m.12315G>A, m.14459G>A, m.652insG, m.14846G>A, m.13513G>A, m.1555A>G, m.15059G>A, m.3256C>T). According to the obtained results, three mutations of the human mitochondrial genome correlated with myocardial infarction. A positive correlation was observed for mutation m.5178C>A. At the same time, a highly significant negative correlation with myocardial infarction was observed for mutation m.14846G>A. One single-nucleotide substitution of m.12315G>A had a trend towards negative correlation. These mutations can potentially be useful for creating molecular/cellular models for studying the mechanisms of myocardial infarction and designing novel therapies. Moreover, these mutations can possibly be used for diagnostic purposes.