TREM-1 as a Marker of Multiple Organ Failure in Cardiac Surgery.

Systemic inflammatory response syndrome (SIRS) frequently accompanies early postoperative period after cardiac surgery and in some cases is complicated by multiple organ failure (MOF). Inherited variation in the innate immune response genes (e.g., TREM1) is among the major factors determining the development of SIRS and the risk of MOF. This research was aimed to study whether the polymorphisms within the TREM1 gene are associated with MOF after the coronary artery bypass graft (CABG) surgery. Here we enrolled 592 patients who underwent CABG surgery in the Research Institute for Complex Issues of Cardiovascular Diseases (Kemerovo, Russia) and documented 28 cases of MOF. Genotyping was performed by allele-specific PCR using TaqMan probes. In addition, we measured serum soluble triggering receptor expressed on myeloid cells 1 (sTREM-1) using enzyme-linked immunosorbent assay. Five polymorphisms (rs1817537, rs2234246, rs3804277, rs7768162 andrs4711668) within the TREM1 gene were significantly associated with MOF. Patients with MOF had higher serum sTREM-1 as compared with those without MOF at both pre- and post-intervention stages. Serum sTREM-1 was associated with the rs1817537,rs2234246 and rs3804277 polymorphisms within the TREM1 gene. Minor alleles within the TREM1 gene define the level of serum sTREM-1 and are associated with MOF after CABG surgery.

Atorvastatin Can Modulate DNA Damage Repair in Endothelial Cells Exposed to Mitomycin C.

HMG-CoA reductase inhibitors (statins) are widely used in the therapy of atherosclerosis and have a number of pleiotropic effects, including DNA repair regulation. We studied the cytogenetic damage and the expression of DNA repair genes (DDB1, ERCC4, and ERCC5) in human coronary artery (HCAEC) and internal thoracic artery endothelial cells (HITAEC) in vitro exposed to mitomycin C (MMC) (positive control), MMC and atorvastatin (MMC+Atv), MMC followed by atorvastatin treatment (MMC/Atv) and 0.9% NaCl (negative control). MMC/Atv treated HCAEC were characterized by significantly decreased micronuclei (MN) frequency compared to the MMC+Atv group and increased nucleoplasmic bridges (NPBs) frequency compared to both MMC+Atv treated cells and positive control; DDB1, ERCC4, and ERCC5 genes were upregulated in MMC+Atv and MMC/Atv treated HCAEC in comparison with the positive control. MMC+Atv treated HITAEC were characterized by reduced MN frequency compared to positive control and decreased NPBs frequency in comparison with both the positive control and MMC/Atv group. Nuclear buds (NBUDs) frequency was significantly lower in MMC/Atv treated cells than in the positive control. The DDB1 gene was downregulated in the MMC+Atv group compared to the positive control, and the ERCC5 gene was upregulated in MMC/Atv group compared to both the positive control and MMC+Atv group. We propose that atorvastatin can modulate the DNA damage repair response in primary human endothelial cells exposed to MMC in a cell line- and incubation scheme-dependent manner that can be extremely important for understanding the fundamental aspects of pleoitropic action of atorvastatin and can also be used to correct the therapy of patients with atherosclerosis characterized by a high genotoxic load.

Identification of Key Genes and Pathways in Genotoxic Stress Induced Endothelial Dysfunction: Results of Whole Transcriptome Sequencing.

Atherosclerosis is a leading cause of cardiovascular morbidity and mortality worldwide. Endothelial disfunction underlying the atherogenesis can be triggered by genotoxic stress in endothelial cells. In the presented research whole transcriptome sequencing (RNA-seq) of human coronary artery (HCAEC) and internal thoracic artery (HITAEC) endothelial cells in vitro exposed to 500 ng/mL mitomycin C (treatment group) or 0.9% NaCl (control group) was performed. Resulting to bioinformatic analysis, 56 upregulated differentially expressed genes (DEGs) and 6 downregulated DEGs with absolute fold change ≥ 2 and FDR p-value < 0.05 were selected in HCAEC exposed to mitomycin C compared to the control group; in HITAEC only one upregulated DEG was found. According to Gene Ontology enrichment analysis, DEGs in HCAEC were classified into 25 functional groups of biological processes, while in HITAEC we found no statistically significant (FDR p-value < 0.05) groups. The four largest groups containing more than 50% DEGs ("signal transduction", "response to stimulus", "biological regulation", and "regulation of biological process") were identified. Finally, candidate DEGs and pathways underlying the genotoxic stress induced endothelial disfunction have been discovered that could improve our understanding of fundamental basis of atherogenesis and help to justification of genotoxic stress as a novel risk factor for atherosclerosis.

Early Postoperative Immunothrombosis of Bioprosthetic Mitral Valve and Left Atrium: A Case Report.

A 72-year-old female patient with mixed rheumatic mitral valve disease and persistent atrial fibrillation underwent mitral valve replacement and suffered from a combined thrombosis of the bioprosthetic valve and the left atrium as soon as 2 days post operation. The patient immediately underwent repeated valve replacement and left atrial thrombectomy. Yet, four days later the patient died due to the recurrent prosthetic valve and left atrial thrombosis which both resulted in an extremely low cardiac output. In this patient's case, the thrombosis was notable for the resistance to anticoagulant therapy as well as for aggressive neutrophil infiltration and release of neutrophil extracellular traps (NETs) within the clot, as demonstrated by immunostaining. The reasons behind these phenomena remained unclear, as no signs of sepsis or contamination of the BHV were documented, although the patient was diagnosed with inherited thrombophilia that could impede the fibrinolysis. The described case highlights the hazard of immunothrombosis upon valve replacement and elucidates its mechanisms in this surgical setting.

Genomic instability in chronic obstructive pulmonary disease and lung cancer: A systematic review and meta-analysis of studies using the micronucleus assay.

Respiratory tissues are highly susceptible to diseases due to the constant exposure to physical and chemical airborne pollutants. Chronic obstructive pulmonary disease (COPD) and lung cancer are among the most common causes of serious illness and death worldwide. The inflammatory environment associated with these respiratory diseases has long been accepted as the major player in the development of airway abnormalities. The presence and relevance of DNA damage and genomic instability makes the micronucleus assay a suitable candidate to quantitatively estimate these early pathogenetic events. A systematic review and meta-analysis were planned to determine underlying common mechanisms that can explain the relationships between COPD and lung cancer. A total of 17 studies from Jan 1999 to Dec 2019 comparing micronucleus frequency in patients affected by respiratory diseases vs healthy controls were analysed. Our results confirmed the presence of significant association between MN frequency and the diseases investigated, and suggested a circle of events linking inflammation induced oxidative stress to the risk of disease through genomic instability and hypoxia. Therefore, using non-invasive, robust and cost effective genomic instability assays such as the micronucleus assay, would allow us to capture unique phenotypic and biological changes that would allow the identification of subjects at high risk of developing lung diseases and improve early detection strategies.

Mitomycin C induced genotoxic stress in endothelial cells is associated with differential expression of proinflammatory cytokines.

Mitomycin C (MMC) is an alkylating chemotherapy drug that causes DNA crosslinking resulting in transcription arrest and apoptosis. DNA crosslinking is a critical damage to DNA that can be caused not only by MMC and other antitumor drugs, but also by various environmental and anthropogenic endo- and exogenous agents. Mammalian cells exposed to alkylating mutagens are characterized by severe genotoxic stress. Somatic mutations and genotoxic stress may lead to endothelial dysfunction, which is the initial stage of atherosclerosis, a leading cause of morbidity and mortality worldwide. Here we studied DNA damage, protein secretion and gene expression of IL6 and IL8 in primary human coronary artery endothelial cells (HCAEC) and human internal thoracic artery endothelial cells (HITAEC) in vitro exposed to 500 ng/mL MMC. We observed an increase in levels of cytogenetic damage (micronuclei, nucleoplasmic bridges and nuclear buds) in MMC-treated cells compared to control cells. After 6 h incubation with MMC, both HCAEC and HITAEC displayed a decrease in IL8 concentration and the mRNA level of IL6 and IL8 compared to control cells. Removal of MMC from cultures after 6 h followed by 24 h incubation of cells in complete growth media led to a sharp increase in secretion and gene expression of the studied cytokines in both HCAEC and HITAEC. Moreover, HCAEC were more susceptible to mutagenic exposure compared to HITAEC. These findings suggest that the MMC-induced genotoxic stress in endothelial cells derived from different arteries is associated with differential secretion and gene expression of proinflammatory cytokines IL6 and IL8.

Modifications in routine protocol of RNA isolation can improve quality of RNA purified from adipocytes.

Adipose tissue is of interest in the context of its role in the pathogenesis of cardiovascular diseases. Modern experimental techniques require a well-purified RNA, but all the routine protocols for RNA extraction have a number of limitations in case of fatty tissues. Here we described a modified protocol for RNA extraction from human adipocytes based on routine column method. Suggested modifications optimized the sample preparation, lysis and washing lead to enhance RNA purity. We conclude that the current protocol for total RNA purification from adipocytes allows extracting a high-quality RNA devoid of fatty acids, organic solvents and salts contamination.

Association of DNA repair gene polymorphisms with genotoxic stress in underground coal miners.

In underground coal mining, numerous harmful substances and ionising radiation pose a major threat to the occupational safety and health of workers. Because cell DNA repair machinery eliminates genotoxic stress conferred by these agents, we examined whether single nucleotide polymorphisms in hOGG1 (rs1052133), XRCC1 (rs25487), ADPRT (rs1136410), XRCC4 (rs6869366) and LIG4 (rs1805388) genes modulate the genotoxic damage assessed by the cytokinesis-block micronucleus assay in lymphocytes from 143 underground coal miners and 127 healthy non-exposed males. We also analyzed models of gene-gene interactions associated with increased cytogenetic damage in coal miners and determined 'protective' and 'risk' combinations of alleles. We showed that miners with the G/G genotype of the hOGG1 (rs1052133) gene had a significantly increased frequency of binucleated lymphocytes with micronuclei (13.17‰, 95% CI = 10.78-15.56) compared to the C/C genotype carriers (10.35‰, 95% CI = 9.59-11.18). In addition, in the exposed group this indicator was significantly increased in carriers of the T/T genotype of the LIG4 (rs1805388) gene compared to miners harbouring the C/T genotype (13.00‰, 95% CI = 10.96-15.04 and 9.69‰, 95% CI = 8.32-11.06, respectively). Using the multifactor dimensionality reduction method, we found the three-locus model of gene-gene interactions hOGG1 (rs1052133) × ADPRT (rs1136410) × XRCC4 (rs6869366) associated with high genotoxic risk in coal miners. These results indicate that the studied polymorphisms and their combinations are associated with cytogenetic status in miners and may be used as molecular predictors of occupational risks in underground coal mines.

Polymorphisms of GSTM1, GSTT1, GSTP1 genes and chromosomal aberrations in lung cancer patients.

PURPOSE: To study the potential links between genetic polymorphisms in the GSTT1, GSTM1, GSTP1 genes and the frequency of chromosomal aberrations (CAs) in lung cancer patients and healthy residents in Russian Federation. METHODS: 200 cells in well-spread metaphase with 46 chromosomes were examined for 353 newly diagnosed lung cancer patients (males) who received medical treatment in the Kemerovo Regional Oncology Center (Kemerovo, Russian Federation), and 300 healthy males from Kemerovo, Russian Federation. The polymorphisms of the GSTM1 del and GSTT1 del genes were analysed by multiplex PCR. Genotyping of the polymorphic variants in the GSTP1 (A313G, T341C) gene was performed using Real-time PCR with competing TaqMan probes complementary to the polymorphic DNA sites. The data analysis was performed using software STATISTICA 8.0 (StatSoft Inc., USA). RESULTS: We discovered that a GSTM1 del polymorphism increases the frequency of chromosomal damage in smoking patients with lung cancer, a general group of lung cancer patients, donors with non-small cell lung cancer and patients in the latest stages of the malignant process. The synergetic effects of occupational exposure and the malignant process can induce some modifications in the cytogenetic status in lung cancer patients harbouring the GSTM1 del polymorphism. CONCLUSIONS: CAs in peripheral blood lymphocytes can be used as biomarkers of the early biological effects of exposure to genotoxic carcinogens and may predict future cancer incidence in several epidemiologic studies. Genetic changes in genes encoding phase II detoxification enzymes are linked to decreases in the metabolic detoxification of environmentally derived genotoxic carcinogens.

Assessment of DNA damage in underground coal miners using the cytokinesis-block micronucleus assay in peripheral blood lymphocytes.

Coal miners are exposed to coal dust, containing mineral particles, inorganic compounds and polycyclic aromatic hydrocarbons, and to ionizing radiation. These factors can induce oxidative stress and promote inflammation that leads to DNA damage. The aim of this investigation is to analyse the degree of DNA damage in miners working in underground coal mines in Kemerovo Region (Russian Federation) using the cytokinesis-block micronucleus assay (CBMN) in peripheral blood lymphocytes. The exposed group included 143 coal miners (mean age = 50.11±7.36 years; mean length of service in coal mining conditions = 23.26±9.66 years). As a control group, we have used venous blood extracted from 127 healthy non-exposed men. The mean age in this group was 47.67±8.45 years. We have discovered that coal miners are characterized by a significant increase in the frequency of binucleated lymphocytes with micronuclei (MN), nucleoplasmic bridges (NPBs) and protrusions (NBUDs) compared to non-exposed donors. In addition, we report, for the first time, a reduction of cell proliferation in a cohort of coal miners. These data are evidence of the genotoxic and cytostatic effects of occupational harmful factors of the coal mining industry. No correlation between the level of chromosome damage and age, smoking status or length of service in coal mining conditions were discovered. We suggest that the CBMN assay would be useful in biomonitoring studies to monitor hygiene and prevention strategies in occupational settings in coal mining countries.

DNA excision repair and double-strand break repair gene polymorphisms and the level of chromosome aberration in children with long-term exposure to radon.

PURPOSE: To study polymorphic variants of repair genes in people affected by long-term exposure to radon. The chromosome aberration frequency in peripheral blood lymphocytes was used as the biological marker of genotoxicity. MATERIALS AND METHODS: Genotyping of 12 single nucleotide polymorphisms in DNA repair genes (APE, XRCC1, OGG1, ADPRT, XpC, XpD, XpG, Lig4 and NBS1) was performed in children with long-term resident exposure to radon. Quantification of the aberrations was performed using light microscopy. RESULTS: The total frequency of aberrations was increased in carriers of the G/G genotype for the XpD gene (rs13181) polymorphism in recessive model confirmed by the results of ROC-analysis ('satisfactory predictor', AUC = 0.609). Single chromosome fragments frequency was increased in carriers of the G/G genotype in comparison with the T/T genotype. In respect to the total frequency of aberrations, the G/G genotype for the XpG gene (rs17655) polymorphism was also identified as a 'satisfactory predictor' (AUC = 0.605). Carriers of the T/C genotype for the ADPRT gene (rs1136410) polymorphism were characterized by an increased level of single fragments relative to the T/T genotype. CONCLUSION: The relationships with several types of cytogenetic damage suggest these three SNP (rs13181, rs17655 and rs1136410) may be considered radiosensitivity markers.

Associations of DNA-repair gene polymorphisms with a genetic susceptibility to ionizing radiation in residents of areas with high radon (222Rn) concentration.

PURPOSE: To investigate the individual radiosensitivity of the human genome in long-term residents of areas with high radon concentration. MATERIALS AND METHODS: The materials used for this investigation were venous blood samples extracted from children living in the boarding school of Tashtagol (Kemerovo Region, Russia). Cytogenetic damage assessment was performed using the cytokinesis-block micronucleus assay (CBMN) on peripheral blood lymphocytes. PCR, gel electrophoresis and product detection using a transilluminator were used to determine polymorphisms in the genes ADPRT (rs 1136410), hOGG1 (rs 1052133), NBS1 (rs 1805794), XRCC1 (rs 25487), XpC (rs 2228001), XpD (rs 13181), and XpG (rs 17655). Statistical analysis was performed using nonparametric methods. To ensure accurate results, FDR-correction for multiple comparisons was performed. RESULTS: We discovered a significant increase in the frequency of binucleated lymphocytes with micronuclei (MN) in carriers of the His/His genotype of the XpG gene Asp1104His polymorphism in comparison to heterozygous and homozygous carriers of the Asp allele. In addition, the Ala/Ala genotype for the ADPRT gene Val762Ala polymorphism and the Glu/Gln genotype for the NBS1 gene Glu185Gln polymorphism were associated with the elevated frequency of binucleated lymphocytes with nucleoplasmic bridges (NPB). CONCLUSIONS: As a result of this study, the elevated frequency of cytogenetic damage in people with particular DNA-repair gene polymorphisms in response to chronic exposure to radon was demonstrated. It was shown that the genes and corresponding polymorphisms (the XpG gene Asp1104His polymorphism, the ADPRT gene Val762Ala polymorphism and the NBS1 gene Glu185Gln polymorphism) can be used as molecular genetic markers of increased individual radiosensitivity in long-term residents of areas with high concentrations of radon.