MtDNA mutations linked with left ventricular hypertrophy

Aim: In left ventricular hypertrophy (LVH), the heart muscle thickens. One third of individuals with LVH never complain of heart problems. However, such patients have a high risk of sudden death. LVH can be caused by arterial atherosclerotic lesions. The linkage of mtDNA mutations 652insG, m.5178C>A, m.3336T>C, m.14459G>A, 652delG, m.14846G>A, m.1555A>G, m.15059G>A, m.3256C>T, m.12315G>A and m.13513G>A with atherosclerosis was described earlier by our laboratory. The aim of the study was to analyze the linkage of these mtDNA mutations with LVH.Methods: DNA from white blood cells was isolated using a phenol-chloroform method. PCR-fragments of DNA contained the region of the investigated mutations. The heteroplasmy level of mtDNA mutations was analyzed using a pyrosequencing-based method developed by our laboratory.Results: We investigated two groups of individuals. One hundred and ninety-four patients with LVH. Two hundred and ten were conventionally healthy. It was found that mtDNA mutation m.5178C>A was significantly associated with LVH. Single nucleotide replacement m.1555A>G was associated with LVH at the level of significance P ≤ 0.1. At the same time m.12315G>A and m.3336T>C were significantly associated with the absence of this pathology. Single nucleotide replacement m.14459G>A was associated with the absence of LVH at the significance level P ≤ 0.1.Conclusion: MtDNA mutations m.5178C>A and m.1555A>G can be used for molecular genetic assessment of the predisposition of individuals to the occurrence of left ventricular hypertrophy. They can also be used for the family analysis of this pathology. Mutations m.12315G>A, m.3336T>C and m.14459G>A can be used in the development of LVH gene therapy methods

Association of mitochondrial mutations with the age of patients having atherosclerotic lesions

Mitochondrial genome mutations are associated with different pathologies. Earlier the authors of the study found an association of some mitochondrial genome mutations with atherosclerosis. In the present study, an attempt to analyze a connection of detected mutations with the age of patients with atherosclerosis was made. The investigated sample included 700 individuals, examined by ultrasonography in polyclinics of Moscow and the Moscow region. The sample was divided approximately into two equal parts. The first part included patients with carotid atherosclerosis. The second part included conventionally healthy study participants. In PCR-fragments of individuals' DNA the heteroplasmy level of investigated mutations was quantitatively measured by the method, developed by members of our laboratory on the basis of pyrosequencing technology. According to the obtained results mutations G12315A, G14459A and G15059A were significantly associated with the age of the study participants. The same time one nucleotide replacements A1555G and G14846A correlated negatively with the age at a high level of significance. Thus, in the present study an association of atherogenic mitochondrial genome mutations with age was found. Antiatherogenic mutations were correlated with the age negatively. This prompts a suggestion about common mechanisms of atherogenesis and aging

Role of Mitochondrial Genome Mutations in Pathogenesis of Carotid Atherosclerosis

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

Mitochondrial mutations associated with cardiac angina

Aim: Cardiac angina is a disease in which discomfort or retrosternal pain may occur. Atherosclerosis of coronary arteries is one of the main risk factors for cardiac angina. The aim of the investigation was to analyze the association of 11 mitochondrial genome mutations with cardiac angina. In our preliminary studies an association of these mutations with atherosclerosis, a risk factor for cardiac angina, was found.Methods: We used samples of white blood cells collected from 192 patients with cardiac angina and 201 conventionally healthy study participants. DNA from blood leukocyte samples was isolated using a phenol-chloroform method. DNA amplicons containing the investigated regions of 11 mitochondrial genome mutations (m.12315G>A, m.652delG, m.5178C>A, m.14459G>A, m.3336T>C, 652insG, m.3256C>T, m.1555A>G, m.15059G>A, m.13513G>A, m.14846G>A) were pyrosequenced. The heteroplasmy level of mitochondrial DNA (mtDNA) mutations was analyzed using a method developed by our laboratory on the basis of pyrosequencing technology.Results: According to the obtained data, three mitochondrial mutations of human genome correlated with cardiac angina. A positive correlation was observed for mutation m.14459G>A (P ≤ 0.05). One single nucleotide substitution m.5178C>A (P ≤ 0.1) had a trend for positive correlation. A negative correlation for mutation m.15059G>A with cardiac angina (P ≤ 0.05) was found.Conclusion: MtDNA mutations m.14459G>A and m.5178C>A can be used for evaluation the predisposition of individuals to atherosclerotic lesions. At the same time, mitochondrial genome mutation m.15059G>A may be used for gene therapy of atherosclerosis

Cybrid Models of Pathological Cell Processes in Different Diseases

Modelling of pathological processes in cells is one of the most sought-after technologies of the 21st century. Using models of such processes may help to study the pathogenetic mechanisms of various diseases. The aim of the present study was to analyse the literature, dedicated to obtaining and investigating cybrid models. Besides, the possibility of modeling pathological processes in cells and treatment of different diseases using the models was evaluated. Methods of obtaining Rho0 cell cultures showed that, during their creation, mainly a standard technique, based on the use of mtDNA replication inhibitors (ethidium bromide), was applied. Cybrid lines were usually obtained by PEG fusion. Most frequently, platelets acted as donors of mitochondria. According to the analysis of the literature data, cybrid cell cultures can be modeled to study the dysfunction of the mitochondrial genome and molecular cellular pathological processes. Such models can be very promising for the development of therapeutic approaches to the treatment of various human diseases

Potential use of buccal epithelium for genetic diagnosis of atherosclerosis using mtDNA mutations

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

New markers of atherosclerosis: a threshold level of heteroplasmy in mtDNA mutations

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 with atherosclerosis. The authors suggest that threshold heteroplasmy levels of these mutations is a new criterion for evaluation of predisposition to the occurrence and development of atherosclerotic lesions in human arteries

Mitochondrial Genome Mutations Associated with Myocardial Infarction

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

Mosaicism of mitochondrial genetic variation in atherosclerotic lesions of the human aorta

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