Genomic Damage Research Articles

Evaluation of human genomic DNA damage caused by H2O2 in vitro using single-cell gel electrophoresis

Evaluation of human genomic DNA damage caused by H2O2 in vitro using single-cell gel electrophoresis

In vitro analysis reveals necroptotic signaling does not provoke DNA damage or HPRT mutations

Most anticancer drugs provoke apoptotic signaling by damaging DNA or other means. Genotoxic therapies may enhance a patient’s risk of developing “therapy-related cancers” due to the accumulation of oncogenic mutations that may occur in noncancerous cells. Mutations can also form upon apoptotic signaling due to sublethal caspase activity, implying that apoptosis activating drugs may also be oncogenic. Necroptosis is a different way of killing cancer cells: this version of caspase-independent cell death is characterized by receptor-interacting protein kinase-3 (RIPK3) and mixed lineage kinase-like domain protein (MLKL) activation, leading to cell membrane rupture and controlled cell lysis. The mutagenic potential of sublethal necroptotic signaling has not yet been directly investigated. Smac mimetics drugs, which activate apoptotic or necroptotic cell death, do not induce mutations but the mechanistic basis for this lack of mutagenic activity has not been determined. In this study, we compared the mutagenic potential of these two cell death pathways by engineering cells to activate either apoptotic or necroptotic signaling by exposing them to Smac mimetics with or without TNFα, and/or enforcing or preventing expression of apoptotic or necroptotic regulators. We discovered that sublethal concentrations of Smac mimetics in contexts that activated apoptotic signaling provoked DNA damage and mutations in surviving cells. Mutagenesis was dependent on executioner caspase activation of the nuclease CAD. In contrast, RIPK3- and MLKL-dependent necroptotic signaling following Smac mimetic treatment was not mutagenic. Likewise, DNA damage was not provoked in cells expressing a lethal constitutively active MLKL mutant. These data reveal that cells surviving sublethal necroptotic signaling do not sustain genomic damage and provide hope for a reduced risk of therapy-related malignancies in patients treated with necroptosis-inducing drugs.

Helicobacter pylori infection downregulates the DNA glycosylase NEIL2, resulting in increased genome damage and inflammation in gastric epithelial cells

Infection with the Gram-negative, microaerophilic bacterium Helicobacter pylori induces an inflammatory response and oxidative DNA damage in gastric epithelial cells that can lead to gastric cancer (GC). However, the underlying pathogenic mechanism is largely unclear. Here, we report that the suppression of Nei-like DNA glycosylase 2 (NEIL2), a mammalian DNA glycosylase that specifically removes oxidized bases, is one mechanism through which H. pylori infection may fuel the accumulation of DNA damage leading to GC. Using cultured cell lines, gastric biopsy specimens, primary cells, and human enteroid-derived monolayers from healthy human stomach, we show that H. pylori infection greatly reduces NEIL2 expression. The H. pylori infection-induced downregulation of NEIL2 was specific, as Campylobacter jejuni had no such effect. Using gastric organoids isolated from the murine stomach in coculture experiments with live bacteria mimicking the infected stomach lining, we found that H. pylori infection is associated with the production of various inflammatory cytokines. This response was more pronounced in Neil2 knockout (KO) mouse cells than in WT cells, suggesting that NEIL2 suppresses inflammation under physiological conditions. Notably, the H. pylori-infected Neil2-KO murine stomach exhibited more DNA damage than the WT. Furthermore, H. pylori-infected Neil2-KO mice had greater inflammation and more epithelial cell damage. Computational analysis of gene expression profiles of DNA glycosylases in gastric specimens linked the reduced Neil2 level to GC progression. Our results suggest that NEIL2 downregulation is a plausible mechanism by which H. pylori infection impairs DNA damage repair, amplifies the inflammatory response, and initiates GC.

The Basis of Peracetic Acid Inactivation Mechanisms for Rotavirus and Tulane Virus under Conditions Relevant for Vegetable Sanitation.

We determined the disinfection efficacy and inactivation mechanisms of peracetic acid (PAA)-based sanitizer using pH values relevant for vegetable sanitation against rotavirus (RV) and Tulane virus (TV; a human norovirus surrogate). TV was significantly more resistant to PAA disinfection than RV: for a 2-log10 reduction of virus titer, RV required 1 mg/liter PAA for 3.5 min of exposure, while TV required 10 mg/liter PAA for 30 min. The higher resistance of TV can be explained, in part, by significantly more aggregation of TV in PAA solutions. The PAA mechanisms of virus inactivation were explored by quantifying (i) viral genome integrity and replication using reverse transcription-quantitative PCR (RT-qPCR) and (ii) virus-host receptor interactions using a cell-free binding assay with porcine gastric mucin conjugated with magnetic beads (PGM-MBs). We observed that PAA induced damage to both RV and TV genomes and also decreased virus-receptor interactions, with the latter suggesting that PAA damages viral proteins important for binding its host cell receptors. Importantly, the levels of genome-versus-protein damage induced by PAA were different for each virus. PAA inactivation correlated with higher levels of RV genome damage than of RV-receptor interactions. For PAA-treated TV, the opposite trends were observed. Thus, PAA inactivates each of these viruses via different molecular mechanisms. The findings presented here potentially contribute to the design of a robust sanitation strategy for RV and TV using PAA to prevent foodborne disease.IMPORTANCE In this study, we examined the inactivation mechanisms of peracetic acid (PAA), a sanitizer commonly used for postharvest vegetable washing, for two enteric viruses: Tulane virus (TV) as a human norovirus surrogate and rotavirus (RV). PAA disinfection mechanisms for RV were mainly due to genome damage. In contrast, PAA disinfection in TV was due to damage of the proteins important for binding to its host receptor. We also observed that PAA triggered aggregation of TV to a much greater extent than RV. These studies demonstrate that different viruses are inactivated via different PAA mechanisms. This information is important for designing an optimal sanitation practice for postharvest vegetable washing to minimize foodborne viral diseases.

Accidental Use of Milk With an Increased Concentration of Aflatoxins Causes Significant DNA Damage in Hospital Workers Exposed to Ionizing Radiation.

The occupational exposure to ionizing radiation (Irad) or associated with mycotoxin-contaminated food may lead to genome damage and contribute to health risk. DNA damage in 80 blood samples of hospital workers occupationally exposed to low—doses of Irad was compared with 80 healthy controls. Among them, 40 participants accidentally consumed milk with increased concentration of Aflatoxin. All participants underwent the testing for micronuclei from blood, and 40 of them 8-OHdG from urine. The frequency of micronuclei (MN) was analyzed by cytokinesis-block peripheral blood lymphocytes and the level of urinary 8-hydroxy-2′-deoxyguanosine (8-OHdG) by ELISA. The Irad led to increased frequency of MN (p < 0.05) and 8-OHdG level at exposed hospital workers. The consumption of milk with increased concentration of aflatoxin probably raised MN frequency and 8-OHdG value. Higher consumption of aflatoxin-contaminated milk (≥2 L/monthly) caused significantly increased MN frequency and 8-OHdG value in comparison to lower milk intake (≤0.5 L/monthly). Also, confounding factors, such as age, gender, and smoking status of all participants were included in the study. The obtained results revealed an increased incidence of MN and 8-OHdG level among hospital workers exposed to low-doses of IRad and milk with increased aflatoxin concentration.

Characterisation of Ovarian Cancer Cell Line NIH-OVCAR3 and Implications of Genomic, Transcriptomic, Proteomic and Functional DNA Damage Response Biomarkers for Therapeutic Targeting.

In order to be effective models to identify biomarkers of chemotherapy response, cancer cell lines require thorough characterization. In this study, we characterised the widely used high grade serous ovarian cancer (HGSOC) cell line NIH-OVCAR3 using bioinformatics, cytotoxicity assays and molecular/functional analyses of DNA damage response (DDR) pathways in comparison to an ovarian cancer cell line panel. Bioinformatic analysis confirmed the HGSOC-like features of NIH-OVCAR3, including low mutation frequency, TP53 loss and high copy number alteration frequency similar to 201 HGSOCs analysed (TCGA). Cytotoxicity assays were performed for the standard of care chemotherapy, carboplatin, and DDR targeting drugs: rucaparib (a PARP inhibitor) and VE-821 (an ATR inhibitor). Interestingly, NIH-OVCAR3 cells showed sensitivity to carboplatin and rucaparib which was explained by functional loss of homologous recombination repair (HRR) identified by plasmid re-joining assay, despite the ability to form RAD51 foci and absence of mutations in HRR genes. NIH-OVCAR3 cells also showed high non-homologous end joining activity, which may contribute to HRR loss and along with genomic amplification in ATR and TOPBP1, could explain the resistance to VE-821. In summary, NIH-OVCAR3 cells highlight the complexity of HGSOCs and that genomic or functional characterization alone might not be enough to predict/explain chemotherapy response.

Simplified modeling of E. coli mortality after genome damage induced by UV-C light exposure

UV light is a group of high-energy waves from the electromagnetic spectrum. There are three types of UV radiations: UV-A, -B and -C. UV-C light are the highest in energy, but most are retained by the ozone layer. UV-A and -B reach the earth’s surface and cause damage on living organisms, being considered as mutagenic physical agents. Numerous test models are used to study UV mutagenicity; some include special lamps, cell cultures and mathematical modeling. Mercury lamps are affordable and useful sources of UV-C light due to their emission at near the maximum absorption peak of nucleic acids. E. coli cultures are widely used because they have DNA-damage and -repairing mechanisms fairly similar to humans. In here we present two simple models that describe UV-C light incidence on a genome matrix, using fundamental quantum–mechanical concepts and considering light as a particle with a discontinuous distribution. To test the accuracy of our equations, stationary phase cultures of several E. coli strains were exposed to UV-C light in 30 s-intervals. Surviving CFUs were counted and survival/mortality curves were constructed. These graphs adjusted with high goodness of fit to the regression predictions. Results were also analyzed using three main parameters: quantum yield, specific speed and time of mortality.

Association between severity score, inflammatory levels and DNA damage in intensive care patients

Background and Objectives: The Intensive Care Unit (ICU) is responsible for the treatment of critical patients and monitoring it continuously can improve the quality of care provided. This study aims to associate the Simplified Acute Physiology Score (SAPS 3) with inflammatory levels and genomic damage in patients admitted to the ICU of a hospital in Vale do Taquari, Rio Grande do Sul, Brazil. Methods: This is a cross-sectional study conducted with 22 patients from an adult ICU,between January and June 2016. The SAPS 3 was scored by the medical staff at the admission of patients and blood samples were obtained after 24 and 72 hours of hospitalization for C-Reactive Protein (CRP) dosing and DNA damage. Results: The SAPS 3 score was not associated with 24-and 72-hours CRP. However, the SAPS 3 score was significantly associated with the index and frequency of DNA damage, only after 72 hours of hospitalization. Conclusion: The severity score was not associated with CRP levels, but with DNA damage only after 72 hours of admission. Critical Care. Simplified Acute Physiology Score. Polymerase Chain Reaction. DNA damage.

Role of air pollution by particulate matter in the pathogenesis of cardiovascular diseases. Prevention measures

The review highlights contemporary concepts about the role of atmospheric air pollution by particulate matter (PM) in pathogenesis of cardiovascular diseases (CVD). We used publications from the PubMed and Russian Science Citation Index databases. The influence of PM on the development and progression of CVD is considered depending on size, origin, chemical composition, concentration in air. PM with an aerodynamic diameter of ≤2,5 μm (PM2,5) are recognized as the most dangerous. Epidemiological studies have established a dose-dependent effect PM. Oxidative stress, damage of genome of cell and epigenetic changes associated with PM effect are the important component of CVD pathogenesis. Systematization of scientific data through a formalized description helps to understand the pathogenesis of CVD and facilitates its practical use for assessing the risk of occurrence, early diagnosing, prognostication, increasing the effectiveness of treatment, and developing preventive measures.

Single nucleotide polymorphism and expression of genes for immune competent cell proliferation and differentiation in radiation-exposed individuals.

It is known that ionizing radiation influences the expression of the genes that play a key role in the mechanisms of maintaining the stability of cellular homeostasis. As a rule, changes in the transcriptome of an exposed cell occur within the first 24 hours following radiation exposure. And it predetermines early response in the case of genome damage. Later on modulations in gene transcription activity are also possible and could result in a carcinogenic effect. However, in order to find the role of exogenous factors (ionizing radiation), it is also necessary to take into account the contribution of endogenous factors that are able to modify gene transcription activity. This is especially important for long after the onset of radiation exposure. Single nucleotide polymorphisms located in regulatory regions of the genes may belong to this group of factors. The objective of the current study was to analyze the influence of ionizing radiation on the transcription activity of the STAT3, GATA3, NFkB1, PADI4 genes, which regulate proliferation and differentiation of immune competent human cells; and to assess the potential influence of single nucleotide polymorphisms located in regulatory regions of the genes on the amount of mRNA. The study involved people who had been chronically exposed due to releases of radioactive waste into the Techa River. It was observed that 60 years after the onset of radiation exposure changes in the transcription activity of the NFkB1 and PADI4 genes were registered in people with cumulative doses to RBM within the range 78–3510 mGy. In people who had been chronically exposed, the effect of allelic variations in rs1053023, rs4143094, rs28362491, rs874881 on the level of mRNAs of the STAT3, GATA3, PADI4, NFkB1 genes has not been established.

GENOTOXICITY EFFECT OF CHLOREXIDINE

Chlorexidine is a mouthwash that is chosen by many dentists as an antiseptic and antibacterial. CHX has bactericidal properties in gram-positive and negative bacteria and fungi. Chlorhexidine causes damage to the permeability of bacterial cell membranes so that cytoplasmic fluid in bacterial cells and other cell components with lower molecular weight from inside the cell penetrates out through the cell membrane, causing the bacteria to die. Much research has been done to study the biocompatibility of composite resins, especially cytotoxicity and genotoxicity testing. Genotoxicity tests that are often done are comet tests to see DNA damage and micronuclei tests to see genome damage. CHX increases Fe-dependent lipid peroxidation by splitting oxygen bonds with iron ions in Fentonlike reactions, producing alkoxyl radicals. The ROS reaction of unsaturated lipids on cell membranes and plasma lipoproteins results in the formation of lipid peroxide (malondialdehyde) which can chemically alter proteins and bases nucleic acid. The content of chlorexidine can have genotoxic effects.&#x0D; Keyword: Genotoxic, Chlorexidine, comet assay, micronuclei assay

Micronucleus scoring: An available approach in the evaluation of genomic damage in exfoliative cervicovaginal cells

Micronucleus is small chromatin extranuclear bodies when chromosomes or chromosomal fragments are not included in the nucleus during cell division. Micronucleus formation usually serves as a sensible indicator of genotoxic damage and also a morphological marker of chromosomal instability.

BIK drives an aggressive breast cancer phenotype through sublethal apoptosis and predicts poor prognosis of ER-positive breast cancer

Apoptosis is fundamental to normal animal development and is the target for many anticancer therapies. Recent studies have explored the consequences of “failed apoptosis” where the apoptotic program is initiated but does not go to completion and does not cause cell death. Nevertheless, this failed apoptosis induces DNA double-strand breaks generating mutations that facilitate tumorigenesis. Whether failed apoptosis is relevant to clinical disease is unknown. BCL-2 interacting killer (BIK) is a stress-induced BH3-only protein that stimulates apoptosis in response to hormone and growth factor deprivation, hypoxia, and genomic stress. It was unclear whether BIK promotes or suppresses tumor survival within the context of breast cancer. We investigated this and show that BIK induces failed apoptosis with limited caspase activation and genomic damage in the absence of extensive cell death. Surviving cells acquire aggressive phenotypes characterized by enrichment of cancer stem-like cells, increased motility and increased clonogenic survival. Furthermore, by examining six independent cohorts of patients (total n = 969), we discovered that high BIK mRNA and protein levels predicted clinical relapse of Estrogen receptor (ER)-positive cancers, which account for almost 70% of all breast cancers diagnosed but had no predictive value for hormone receptor-negative (triple-negative) patients. Thus, this study identifies BIK as a biomarker for tumor recurrence of ER-positive patients and provides a potential mechanism whereby failed apoptosis contributes to cancer aggression.

In vitro genomic damage induced by urban fine particulate matter on human lymphocytes

Urban air pollution represents a global problem, since everyday many mutagenic and carcinogens compounds are emitted into the atmosphere, with consequent adverse health effects on humans and biota. Specifically, particulate matter air pollution was associated with increased risks in human mortality and morbidity. In this paper, we analyse the genomic effects on human lymphocytes of different concentrations of annual Turin PM2.5 extract by an in vitro micronuclei assay. Samplings were collected from an urban meteorological-chemical station positioned in Turin (Italy), one of the most polluted cities in Europe. PM2.5 sampled on filters was used for organic extraction in monthly pools and successively aggregated to produce a mixture representative for a full year PM2.5 collection. Lymphocytes were exposed to four concentrations of PM2.5: 5, 10, 15 and 20 μg/mL and micronuclei, nucleoplasmic bridges and nuclear buds were scored. With respect to controls, PM2.5 significantly increased the frequencies of all analysed biomarkers at all tested concentrations, whereas the CBPI index was significantly reduced only at the concentration of 20 μg/mL. Such in vitro effects can both to stimulate local authorities to adopt efficient measures for air pollution mitigation and to improve human monitoring to detect early precancer lesions.

Spatial-temporal genome damaging in the blue crab Cardisoma guanhumi as ecological indicators for monitoring tropical estuaries

In this study, to better our understanding of the current state of conservation of Cardisoma guanhumi and its habitats, we evaluated the potential spatio-temporal genomic damage of this species across five estuaries in Brazil. The experiment was performed over two consecutive years, and the sampling was performed in the winter and summer seasons. Two genetic tests — micronucleus test and comet assay — were used to quantify the DNA damage. Unlike in the summers and in the winter of 2013, in the winter of 2012 a significant increase was noted in the frequency of micronucleated cells and genomic damage index. The occurrence of genomic damage coincided with the arrival of the harsh winter of 2012 as the water sourced from the coastal rivers significantly affected the estuarine species under study. Our results confirmed that this species was resilient to the atypical climatic conditions, which facilitated the generation of excessive waste.

The circadian clock protects against acute radiation-induced dermatitis

Radiation-induced dermatitis is a common occurrence in cancer patients undergoing radiation therapy (RT) and is caused when ionizing radiation (IR) induces DNA strand breaks in skin cells. The wide use of RT in cancer treatments makes it important to minimize RT-induced toxicities including radiodermatitis. This study sought to determine if the circadian clock plays a protective role in minimizing radiodermatitis. We treated mice in control (Day Shift), environmentally-disrupted (Rotating Shift) and genetically-disrupted (Per 1/2−/−) circadian conditions with 6 Gy of IR to the whole body. There was a significantly increased number of radiodermatitis spots on mice with circadian clock disruption compared to control mice. Additionally, circadian clock disrupted mice exhibited reduced protein levels of Bmal1, a phenomenon that sensitized circadian synchronized keratinocytes to IR-induced DNA damage. Furthermore, the skin phenotype results corresponded with significantly reduced body weights and increased genomic DNA damage in blood cells of mice with clock disruption compared to control mice. These findings suggest that the circadian clock plays a protective role in IR-induced DNA damage and skin toxicity, possibly through BMAL1-dependent mechanisms, and potentially impacts RT-associated radiodermatitis in cancer patients.

Nucleosides Rescue Replication-Mediated Genome Instability of Human Pluripotent Stem Cells.

SummaryHuman pluripotent stem cells (PSCs) are subject to the appearance of recurrent genetic variants on prolonged culture. We have now found that, compared with isogenic differentiated cells, PSCs exhibit evidence of considerably more DNA damage during the S phase of the cell cycle, apparently as a consequence of DNA replication stress marked by slower progression of DNA replication, activation of latent origins of replication, and collapse of replication forks. As in many cancers, which, like PSCs, exhibit a shortened G1 phase and DNA replication stress, the resulting DNA damage may underlie the higher incidence of abnormal and abortive mitoses in PSCs, resulting in chromosomal non-dysjunction or cell death. However, we have found that the extent of DNA replication stress, DNA damage, and consequent aberrant mitoses can be substantially reduced by culturing PSCs in the presence of exogenous nucleosides, resulting in improved survival, clonogenicity, and population growth.

Protective effects of zinc L-carnosine against hydrogen peroxide-induced DNA damage and micronucleus formation in CCD-18co human colon fibroblast cells

Zinc L-carnosine (ZnC) is a chelated compound of zinc and L-carnosine. The present study aims to determine the protective effects of ZnC against hydrogen peroxide (H2O2)-induced oxidative stress and genomic damage in CCD-18co human normal colon fibroblast cells. Generally, cells were pretreated with ZnC (0–100 µM) for 24 h before challenged with 20 µM of H2O2 for 1 h to induce oxidative damage. Results showed that pretreatment with ZnC was able to reduce the intracellular ROS level in CCD-18co cells after being challenged with H2O2. Moreover, pretreatment with ZnC demonstrated protection from H2O2-induced DNA strand breaks and micronucleus formation. Our current findings revealed that pretreatment with ZnC could induce the activation of MTF-1 signaling pathway and expression of metallothionein (MT) in a dose-dependent manner. However, ZnC did not have any effects on Nrf2 signaling pathway and the expression of glutathione, superoxide dismutase 1, and glutamate-cysteine ligase catalytic subunit (GCLC). Furthermore, pretreatment with ZnC did not induce the expression of OGG1 and PARP-1 in CCD-18co cells, suggesting that these two DNA repairing enzymes are not related to the genoprotective effects of ZnC. Since the expression of MT has been demonstrated to protect cells from oxidative DNA damage induced by various genotoxic agents, the genoprotective effects of ZnC might be due to the ability of ZnC to induce the expression of MT. In conclusion, ZnC pretreatment was able to protect CCD-18co cells from H2O2-induced genomic damage via the activation of the MTF-1 signalling pathway and the induction of MT expression.

The Impact of Mother's Living Environment Exposure on Genome Damage, Immunological Status, and Sex Hormone Levels in Newborns.

Background: The aim of this study was to compare for the first time IL-6 (Interleukin 6), testosterone (T) and estradiol (E) levels, their ratio (E/T), micronucleus (MN), and nuclear bridge (NB) frequency between newborns with regard to their mother’s residency and diet. Our results should enable an assessment of the possible environmental endocrine effects and interaction between biomarkers, pointing to possible associated health risks. Methods: Fifty full-term newborns of both sexes, whose mothers were healthy and not occupationally exposed to any known carcinogen, were analyzed. All of the mothers filled in a detailed questionnaire. Results: The results showed significantly higher levels of E in newborns of mothers with agricultural residency than those born by mothers with urban residency. Significantly, lower levels of E were measured in newborns of mothers who drank milk and carbonated beverages more frequently. Testosterone was significantly higher in boys of mothers with agricultural residency than from mothers with urban residency. Residence and other parameters had no impact on the difference in MN frequency. IL-6 levels were higher in newborns of mothers with agricultural residency. NB levels were significantly associated with E. A significant association between E levels and IL-6 was found. Conclusion: Our results were the first to show a significant impact of the mother’s agricultural residency and diet on their newborns’ sex hormone and IL-6 levels and their association.

Изменение характеристик внеклеточной ДНК пациентов с кататонической и параноидной формой шизофрении по сравнению со здоровым контролем

Исследованы характеристики вкДНК в плазмах крови подвыборок больных кататонической (КШ, N=46) и параноидной формой (ПШ, N=54) шизофрении в сравнении с выборкой психически здоровых людей соответствующего возраста. Обнаружено, что независимо от типа шизофрении, концентрация вкДНК возрастает почти в 2 раза по сравнению с контролем, и нуклеазная активность плазм крови больных также повышена. Мы определили, что уровень 8-oxodG в мононуклеарах больных КШ и ПШ не различается и значительно выше контроля, и содержание гистонов Н2АХ в двух подвыборках больных шизофренией также значительно выше, чем в лимфоцитах здоровых людей, при этом уровень двунитевых разрывов в подгруппе КШ выше, чем в ПШ. Клетки с двунитевыми разрывами гибнут, пополняя пул вкДНК. Повышенная нуклеазная активность способствует выведению быстро расщепляемых АТ-богатых фрагментов и накоплению GC-богатых фрагментов в составе вкДНК. ВкДНК больных шизофренией обогащена ГЦ-богатыми фрагментами теломерного повтора по сравнению с вкДНК здоровых доноров. В составе вкДНК больных КШ число копий ГЦ-богатого рибосомного повтора увеличено по сравнению с выборкой ПШ и контрольной выборкой. Все исследованные показатели в большей степени изменены в группе пациентов с кататонической формой шизофрении, что может свидетельствовать о более выраженном воспалительном процессе при кататонии. CfDNA parameters of SZ patients with paranoid (N=54) and catatonic SZ (N=46) forms have been analyzed and compared with those of healthy controls. In the subjects from the both SZ forms, the mean cfDNA plasma concentration was twofold higher and NA of the plasma was higher than those in the healthy controls. In addition, peripheral blood lymphocytes of both SZ forms showed elevated levels of oxidized dna (8-OHDG) as well as increased number of double-stranded DNA breaks (flow Cytometry), and the ds-breaks level is higher in catatonic SZ. The cells with genomic DNA damages can undergo to unprogrammed cell death and contribute to circulating cfDNA. Increased DNase I activity in patients with schizophrenia promotes to cleave primarily AT-rich DNA-fragments and the accumulation of GC-rich fragments. Compared to those of healthy controls, plasma cfDNA samples of both SZ forms patients contained increased copy numbers of telomere DNA, as well as ribosomal RNA genes, and cf-rDNA concentration is higher in catatonic SZ group. Changes in cfDNA parameters was significantly higher in the catatonic SZ group, which may indicate a more pronounced inflammatory process.