Increased lymphocyte micronucleus frequency in early pregnancy is associated prospectively with pre-eclampsia and/or intrauterine growth restriction

Role of Oxidative Stress and DNA Damage on Preterm Birth Outcome

Background: Preterm birth (PTB) poses a significant global health challenge and focused research is vital for improving maternal and neonatal health outcomes. The purpose of this study was to determine the effect of oxidative stress (OS) and DNA damage on PTB. Methods: There were two groups: (a) cases consisting of mothers with PTB (<37 weeks of gestation, n = 100) and (b) controls consisting of mothers with term birth (>37 weeks of gestation, n = 100). Women with vaginal infection, non-cephalic presentation, multiple gestations, fetal anomalies, Cesarean delivery, pregnancy with Mullerian anomalies, or preeclampsia were excluded from the study. OS analysis was conducted by measuring levels of superoxide dismutase (SOD), catalase (CAT), lipid peroxidation (LPO), and total protein and DNA damage were evaluated by CBMN-Cyt assay. Statistical analysis was performed using students' t-test and one-way ANOVA. Results: Low levels of antioxidants SOD and CAT (p < .0001), and total protein (p < .0001), besides high malondialdehyde (byproduct of LPO) (p < .0001) were observed in the PTB group. Moreover, high frequencies of micronuclei (p < .0001) and nucleoplasmic buds (p < .01) were detected in the PTB mothers compared to term birth mothers, while no significance was observed in the nucleoplasmic bridge frequencies. Conclusion: When the body's immune system and antioxidants fail to cope up with the generated OS, it can lead to PTB. Along with other body tests, OS markers and CBMN-Cyt tests have the potential to be used in diagnostics for early warning as well as monitoring and advising mothers for a better pregnancy outcome.

Effect of maternal diet on the frequency of micronuclei in pregnant women and newborns: A protocol for systematic review and meta-analysis

BACKGROUND

The effects of diet on maternal and child genetic levels have been previously reported. Diet-associated DNA damage, such as the presence of micronuclei (MN), may be related to an increased risk of developing chronic diseases, such as cancer. Such damage is particularly concerning during pregnancy as it can affect the newborn.

AIM

This review will aim to summarize the primary evidence of the impact of diet during pregnancy on micronucleus frequency in the maternal-newborn population.

METHODS

This protocol was developed based on the Preferred Reporting Items guidelines for Systematic Reviews and Meta-analyses Protocol. The review was registered with the International Register of Prospective Systematic Reviews on February 17, 2022 (registration number: CRD42022302401). We will use PubMed, Embase, Web of Science, Scopus, Science direct, and Google databases to search for observational studies. This review will include studies that investigate the diet consumed by pregnant women and its effect on the frequency of MN in mothers and newborns without any time or language limitations. For data extraction, researchers will independently review the full text and collect information that characterizes the study and its findings. We will analyze the results by calculating the odds ratio for each type of diet evaluated, accompanied by a 95% confidence interval. We will perform a quantitative synthesis of homogeneous studies to perform a meta-analysis. Micronucleus frequency quantifies the effect and will be presented as the mean and standard deviation or median and interquartile range.

EXPECTED RESULTS

This review will aim to identify which dietary patterns during pregnancy may be associated with an increase in the frequency of MN in mothers and their newborns. Understanding the impact of diet on the frequency of MN is essential to deepen studies and to propose strategies that aim to protect the health of the public through food.

The buccal micronucleus cytome assay: New horizons for its implementation in human studies

In this report we provide a summary of the presentations and discussion of the latest knowledge regarding the buccal micronucleus (MN) cytome assay. This information was presented at the HUMN workshop held in Malaga, Spain, in connection with the 2023 European, Environmental Mutagenesis and Genomics conference. The presentations covered the most salient topics relevant to the buccal MN cytome assay including (i) the biology of the buccal mucosa, (ii) its application in human studies relating to DNA damage caused by environmental exposure to genotoxins, (iii) the association of buccal MN with cancer and a wide range of reproductive, metabolic, immunological, neurodegenerative and other age-related diseases, (iv) the impact of nutrition and lifestyle on buccal MN cytome assay biomarkers; (v) its potential for application to studies of DNA damage in children and obesity, and (vi) the growing prospects of enhancing the clinical utility by automated scoring of the buccal MN cytome assay biomarkers by image recognition software developed using artificial intelligence. The most important knowledge gap is the need of prospective studies to test whether the buccal MN cytome assay biomarkers predict health and disease.

Optimizing the Comet Assay-Based In Vitro DNA Repair Assay for Placental Tissue: A Pilot Study with Pre-Eclamptic Patients

The comet assay-based in vitro DNA repair assay has become a common tool for quantifying base excision repair (BER) activity in human lymphocytes or cultured cells. Here, we optimized the protocol for studying BER in human placental tissue because the placenta is a non-invasive tissue for biomonitoring of early-life exposures, and it can be used to investigate molecular mechanisms associated with prenatal disorders. The optimal protein concentration of placental protein extracts for optimal damage recognition and incision was 2 mg protein/mL. The addition of aphidicolin did not lead to reduced non-specific incisions and was, therefore, not included in the optimized protocol. The interval between sample collection and analysis did not affect BER activity up to 70 min. Finally, this optimized protocol was tested on pre-eclamptic (PE) placental tissues (n = 11) and significantly lower BER activity in PE placentas compared to controls (n = 9) was observed. This was paralleled by a significant reduction in the expression of BER-related genes and increased DNA oxidation in PE placentas. Our study indicates that BER activity can be determined in placentas, and lower activity is present in PE compared with healthy. These findings should be followed up in prospective clinical investigations to examine BER's role in the advancement of PE.

Protective Effects of Micronutrient Supplements, Phytochemicals and Phytochemical-Rich Beverages and Foods Against DNA Damage in Humans: A Systematic Review of Randomized Controlled Trials and Prospective Studies

Accumulation of deoxyribonucleic acid (DNA) damage diminishes cellular health, increases risk of developmental and degenerative diseases, and accelerates aging. Optimizing nutrient intake can minimize accrual of DNA damage. The objectives of this review are to: 1) assemble and systematically analyze high-level evidence for the effect of supplementation with micronutrients and phytochemicals on baseline levels of DNA damage in humans, and 2) use this knowledge to identify which of these essential micronutrients or nonessential phytochemicals promote DNA integrity in vivo in humans. We conducted systematic literature searches of the PubMed database to identify interventional, prospective, cross-sectional, or in vitro studies that explored the association between nutrients and established biomarkers of DNA damage associated with developmental and degenerative disease risk. Biomarkers included lymphocyte chromosome aberrations, lymphocyte and buccal cell micronuclei, DNA methylation, lymphocyte/leukocyte DNA strand breaks, DNA oxidation, telomere length, telomerase activity, and mitochondrial DNA mutations. Only randomized, controlled interventions and uncontrolled longitudinal intervention studies conducted in humans were selected for evaluation and data extraction. These studies were ranked for the quality of their study design. In all, 96 of the 124 articles identified reported studies that achieved a quality assessment score ≥ 5 (from a maximum score of 7) and were included in the final review. Based on these studies, nutrients associated with protective effects included vitamin A and its precursor β-carotene, vitamins C, E, B1, B12, folate, minerals selenium and zinc, and phytochemicals such as curcumin (with piperine), lycopene, and proanthocyanidins. These findings highlight the importance of nutrients involved in (i) DNA metabolism and repair (folate, vitamin B12, and zinc) and (ii) prevention of oxidative stress and inflammation (vitamins A, C, E, lycopene, curcumin, proanthocyanidins, selenium, and zinc). Supplementation with certain micronutrients and their combinations may reduce DNA damage and promote cellular health by improving the maintenance of genome integrity.

Androgen Deprivation Freezes Hormone-Sensitive Prostate Cancer Cells in a Reversible, Genetically Unstable Quasi-Apoptotic State, Bursting into Full Apoptosis upon Poly(ADP-ribose) Polymerase Inhibition

Androgen deprivation therapy (ADT) is a powerful treatment for metastatic hormone-sensitive prostate cancer (mHSPC) patients, but eventually and inevitably, cancer relapses, progressing to the fatal castration-resistant (CR)PC stage. Progression implies the emergence of cells proliferating in the absence of androgen through still elusive mechanisms. We show here for the first time that ADT induces LNCaP mHSPC cells to collectively enter a metastable quasi-apoptotic state (QUAPS) consisting of partial mitochondrial permeabilization, limited BAX and caspase activation, and moderate induction of caspase-dependent dsDNA breaks; despite this, cells maintain full viability. QUAPS is destabilized by poly(ADP)-polymerase inhibition (PARPi), breaking off toward overt intrinsic apoptosis and culture extinction. Instead, QUAPS is rapidly and efficiently reverted upon androgen restoration, with mitochondria rapidly recovering integrity and cells collectively resuming normal proliferation. Notably, replication restarts before DNA repair is completed, and implies an increased micronuclei frequency, indicating that ADT promotes genetic instability. The recovered cells re-acquire insensitivity to PARPi (as untreated LNCaP), pointing to specific, context-dependent vulnerability of mHSPC cells to PARPi during ADT. Summarizing, QUAPS is an unstable, pro-mutagenic state developing as a pro-survival pathway stabilized by PARP, and constitutes a novel viewpoint explaining how ADT-treated mHSPC may progress to CRPC, indicating possible preventive countermeasures.

Association between lead exposure and DNA damage (genotoxicity): systematic review and meta-analysis

Studies suggest that chronic lead (Pb) exposure may induce deoxyribonucleic acid (DNA) damage. However, there is no synthesised evidence in this regard. We systematically reviewed existing literature and synthesised evidence on the association between chronic Pb exposure and markers of genotoxicity. Observational studies reporting biomarkers of DNA damage among occupationally Pb-exposed and unexposed controls were systematically searched from PubMed, Scopus and Embase databases from inception to January 2022. The markers included were micronucleus frequency (MN), chromosomal aberrations, comet assay, and 8-hydroxy-deoxyguanosine. During the execution of this review, we followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Mean differences in the biological markers of DNA damage between Pb-exposed and control groups were pooled using the random-effects model. The heterogeneity was assessed using the Cochran-Q test and I² statistic. The review included forty-five studies comparing markers of DNA damage between Pb-exposed and unexposed. The primary studies utilised buccal and/or peripheral leukocytes for evaluating the DNA damage. The pooled quantitative results revealed significantly higher DNA damage characterised by increased levels of MN and SCE frequency, chromosomal aberrations, and oxidative DNA damage (comet assay and 8-OHdG) among Pb-exposed than the unexposed. However, studies included in the review exhibited high levels of heterogeneity among the studies. Chronic Pb exposure is associated with DNA damage. However, high-quality, multicentred studies are required to strengthen present observations and further understand the Pb's role in inducing DNA damage. CRD42022286810.

DNA damage analysis in newborns and their mothers related to pregnancy and delivery characteristics

INTRODUCTION

Increased DNA damage is associated with early events in carcinogenesis. The foetus may be more susceptible to effects of environment by transplacental exposure. We aimed to evaluate DNA damage in cells from umbilical cord (arteries and vein) and maternal blood from pregnant women.

METHODS

Fifty eight pregnant women and their offspring were included in this study. They were submitted to an interview to obtain information about personal history, clinical history, and lifestyle habits. Other Information was obtained from medical records. The samples were prepared for Single Cell Gel/Comet assay and Cytokinesis-block Micronucleus Cytome (CBMN-Cyt) assay.

RESULTS

Correlation between DNA damage frequency by Comet assay from newborns and their mothers was statistically significant and was significantly associated with nulliparity and more than 1 h of second stage of labour (umbilical vein and maternal blood). A positive MNi relationship was noticed for age (mother's blood) and inappropriate birth weight for gestational age (maternal blood). When multivariate statistical analyses were applied to measure the degree of association between variables that influenced DNA damage markers in the first evaluation, inadequate birth weight and pregnant weight gain were associated with MNi frequency in maternal and newborns blood, respectively.

DISCUSSION

Significant associations between DNA damage in newborns and pregnant women, and birth and pregnancy events suggest molecular evidence of transplacental genotoxic effects. However, a potentially increased risk of degenerative diseases, such as cancers, in this population should be carefully investigated by further prospective cohort studies.

"Micronuclei and Disease" special issue: Aims, scope, and synthesis of outcomes

The purpose of the "Micronuclei and Disease" special issue (SI) is to: (i) Determine the level of evidence for association of micronuclei (MN), a biomarker of numerical and structural chromosomal aberrations, with risk of specific diseases in humans; (ii) Define plausible mechanisms that explain association of MN with each disease; (iii) Identify knowledge gaps and research needed to translate MN assays into clinical practice. The "MN and Disease" SI includes 14 papers. The first is a review of mechanisms of MN formation and their consequences in humans. 11 papers are systematic reviews and/or meta-analyses of the association of MN with reproduction, child health, inflammation, auto-immune disease, glycation, metabolic diseases, chronic kidney disease, cardiovascular disease, eleven common cancers, ageing and frailty. The penultimate paper focuses on effect of interventions on MN frequency in the elderly. A road map for translation of MN data into clinical practice is the topic of the final paper. The majority of reviewed studies were case-control studies in which the ratio of mean MN frequency in disease cases relative to controls, i.e. the mean ratio (MR), was calculated. The mean of these MR values, estimated by meta-analyses, for lymphocyte and buccal cell MN in non-cancer diseases were 2.3 and 3.6 respectively, and for cancers they were 1.7 and 2.6 respectively. The highest MR values were observed in studies of cancer cases in which MN were measured in the same tissue as the tumour (MR = 4.9-10.8). This special issue is an important milestone in the evidence supporting MN as a reliable genomic biomarker of developmental and degenerative disease risk. These advances, together with results from prospective cohort studies, are helping to identify diseases in which MN assays can be practically employed in the clinical setting to better identify high risk patients and to prioritise them for preventive therapy.

Roadmap for translating results from the micronucleus assay into clinical practice: From observational studies to randomized controlled trials

According to the definition delivred by the WHO, a biomarker, independently from its role that may be indicative of exposure, response or effect, is inevitably linked to a clinical outcome or to a disease. The presence of a continuum from early biological events to therapy, and prognosis is the unifying mechanism that justifies this conclusion. Traditionally, the technical and inter-individual variability of the assays, together with the long duration between early pathogenetic events and the disease, prevented clinical applications to these biomarkers. These limitations became less important with the emerging of personalized preventive medicine because of the focus on disease prediction and prevention, and the recommended use of all data concerning measurable patient's features. Several papers have been published on the best validation procedures for translating biomarkers to real life. The history of cholesterol concentration is extensively discussed as a reliable example of a biomarker that - after a long and controversial validation process - is currently used in clinical practice. The frequency of micronucleated cells is a reliable biomarker for the pathogenesis of cancer and other non-communicable diseases, and the link with clinical outcomes is substantiated by epidemiological evidence and strong mechanistic basis. Available literature concerning the use of the micronucleus assay in clinical studies is discussed, and a suitable three-levels road-map driving this biomarker towards clinical practice is presented. Under the perspective of personalized medicine, the use of the micronucleus assays can play a decisive role in addressing preventive and therapeutic strategies of chronic diseases. In many cases the MN assay is either currently used in clinical practice or classified as adequate to consider translation into practice. The roadmap to clinical validation of the micronucleus assay finds inspiration from the history of biomarkers such as cholesterol, which clearly showed that the evidence from prospective studies or RCTs is critical to achieve the required level of trust from the healthcare profession. (307 words).

Inflammatory cytokine storms severity may be fueled by interactions of micronuclei and RNA viruses such as COVID-19 virus SARS-CoV-2. A hypothesis

In this review we bring together evidence that (i) RNA viruses are a cause of chromosomal instability and micronuclei (MN), (ii) those individuals with high levels of lymphocyte MN have a weakened immune response and are more susceptible to RNA virus infection and (iii) both RNA virus infection and MN formation can induce inflammatory cytokine production. Based on these observations we propose a hypothesis that those who harbor elevated frequencies of MN within their cells are more prone to RNA virus infection and are more likely, through combined effects of leakage of self-DNA from MN and RNA from viruses, to escalate pro-inflammatory cytokine production via the cyclic GMP-AMP synthase (cGAS), stimulator of interferon genes (STING) and the Senescence Associated Secretory Phenotype (SASP) mechanisms to an extent that is unresolvable and therefore confers high risk of causing tissue damage by an excessive and overtly toxic immune response. The corollaries from this hypothesis are (i) those with abnormally high MN frequency are more prone to infection by RNA viruses; (ii) the extent of cytokine production and pro-inflammatory response to infection by RNA viruses is enhanced and possibly exceeds threshold levels that may be unresolvable in those with elevated MN levels in affected organs; (iii) reduction of MN frequency by improving nutrition and life-style factors increases resistance to RNA virus infection and moderates inflammatory cytokine production to a level that is immunologically efficacious and survivable.

Telomere aberrations, including telomere loss, doublets, and extreme shortening, are increased in patients with infertility

OBJECTIVE

To test the hypothesis that telomere shortening and/or loss are risk factors for infertility.

DESIGN

Retrospective analysis of the telomere status in patients with infertility using conventional cytogenetic data collected prospectively.

SETTING

Academic centers.

PATIENT(S)

Cytogenetic slides with cultured peripheral lymphocytes from 50 patients undergoing fertility treatment and 150 healthy donors, including 100 donors matched for age.

INTERVENTION(S)

Cytogenetic slides were used to detect chromosomal and telomere aberrations.

MAIN OUTCOME MEASURE(S)

Telomere length and telomere aberrations were analyzed after telomere and centromere staining.

RESULT(S)

The mean telomere length of patients consulting for infertility was significantly less than that of healthy donors of similar age. Moreover, patients with infertility showed significantly more extreme telomere loss and telomere doublet formation than healthy controls. Telomere shortening and/or telomere aberrations were more pronounced in patients with structural chromosomal aberrations. Dicentric chromosomes were identified in 6/13 patients, with constitutional chromosomal aberrations leading to chromosomal instability that correlated with chromosomal end-to-end fusions.

CONCLUSION(S)

Our findings demonstrate the feasibility of analyzing telomere aberrations in addition to chromosomal aberrations, using cytogenetic slides. Telomere attrition and/or dysfunction represent the main common cytogenetic characteristic of patients with infertility, leading to potential implications for fertility assessment. Pending further studies, these techniques that correlate the outcome of assisted reproduction and telomere integrity status may represent a novel and useful diagnostic and/or prognostic tool for medical care in this field.

Micronuclei, reproduction and child health

The current review looks for relationships between results from biomarker studies with micronucleus and health effects related to reproduction and children. In adults, an age related increase in MN is well known as well as associations with environmental exposures especially air pollution from traffic and smoking. Literature searches in PubMED and SCOPUS were performed with the following keywords reproduction, children, micronuclei, health effects. In total 162 studies were identified with the keyword children. Concerning children and health and children and environmental exposures, the titles and abstracts of a total of 162 publications were screened for language, inclusion of data from children and selected according to a study selection chart. 9 studies were included for children and health, and 21 studies for children and environmental exposures, with 12 in buccal cells and 9 in lymphocytes. The publications were read and included in tables if data on controls was available. MN frequencies were collected for peripheral blood lymphocytes (PBLs), reticulocytes or buccal cells (BC) and reported as Mean ± SD or Median (IQR). The Mean frequency Ratio, MRi, corresponding to the MN mean for study persons divided by MN mean for control persons was stated as reported in the publication or calculated by us from the data in the publication, where possible. Our systematic analysis revealed a number of positive associations of MN frequencies as a marker of increased health risk in relation to reproduction as well as child health. The majority of studies reported with children concerns exposures of children as well as maternal exposures and newborn health with MN as a biomarker of exposure. Exposure monitoring by MN as biomarker is also reported in studies of school children however most often not related to health effects. The MRis are found in ranges from 1 to 5.5 most studies around 2. As far as MN frequencies in children and exposure are concerned, the MRis range from 0.9 to 5.5, with a range from 1.3-4.9 for lymphocytes and from 1.5 to 2.5 in buccal cells, except for two studies with no differences found between cases and controls. Only one study is available for MRi calculation in reticulocytes with the value of 2.3. These data are supporting MN as a relevant biomarker for children health. However, the data is mostly from small studies with different protocol leaving out the possibility of metanalyses and even statistical comparisons among studies. The actual risk from elevated MNs in children waits large cohort studies with pooled datasets as performed with MN measured in adults. Introduction of buccal cells as non invasive alternative to lymphocytes is increasing and as with the lymphocytes standardised protocols are recommended to enable comparative studies and metaanalyses.

Micronuclei as biomarkers of DNA damage, aneuploidy, inducers of chromosomal hypermutation and as sources of pro-inflammatory DNA in humans

Micronuclei (MNi) are among the most widely studied biomarkers of DNA damage and chromosomal instability in humans. They originate from chromosome fragments or intact chromosomes that are not included in daughter nuclei during mitosis. The main reasons for their formation are a lack of functional centromere in the chromosome fragments or whole chromosomes or defects in one or more of the proteins of the mitotic system that, consequently, fails to segregate chromosomes properly. Assays have been developed to measure MNi in peripheral blood lymphocytes, red blood cells as well as various types of epithelial cells such as buccal, nasal, urothelial and cervical cells. Some of the assays have been further developed into micronucleus (MN) cytome assays to include additional nuclear anomalies, cell death and nuclear division biomarkers. In addition, the use of molecular probes has been adopted widely for the purpose of understanding the mechanistic origin of MNi. MN assays in humans are used for the purpose of investigating the genotoxic effects of adverse environmental, life-style and occupational factors, genetic susceptibility to DNA damage, and for determining risk of accelerated aging and diseases affected by genomic instability such as developmental defects and cancer. The emerging new knowledge showing that chromosomes trapped in MNi can undergo a high rate of fragmentation and become massively re-arranged have highlighted the possibility that MN formation is not only a biomarker of induced DNA damage but also a mechanism that drives hypermutation. Furthermore, another line of recent research showed that DNA and chromatin leaking from disrupted MNi triggers the innate immune cGAS-STING mechanism that promotes inflammation which can cause a wide-range of age-related diseases if left unresolved. For these reasons, MN assays in humans have become an increasingly important biomarker of disease initiation and progression across all life-stages.

Micronuclei, inflammation and auto-immune disease

Auto-immune diseases (AUD) are characterized by an immune response to antigenic components of the host itself. The etiology of AUD is not well understood. The available evidence points to an interaction between genetic, epigenetic, environmental, infectious and life-style factors. AUD are more prevalent in women than in men; sex hormones play a crucial role in this sex bias. Micronuclei (MN) emerged as a new player in the induction of AUD, based on the capacity of DNA-sensors to detect self-DNA that leaks into the cytoplasm from disrupted MN and induce the cGAS-STING pathway triggering an innate auto-immune response and chronic inflammation. It was found that inflammation can induce MN and MN can induce inflammation, leading to a vicious inflammation-oxidative-DNA damage-MN-formation-chromothripsis cycle. MN originating from sex chromosome-loss may induce inflammation and AUD. We performed a systematic review of studies reporting MN in patients with systemic or organ-specific AUD. A meta-analysis was performed on lymphocyte MN in diabetes mellitus (10 studies, 457 patients/290 controls) and Behcet's disease (3 studies, 100 patients/70 controls) and for buccal MN in diabetes mellitus (11 studies, 507 patients/427 controls). A statistically significant increase in patients compared to controls was found in the meta-analyses providing an indication of an association between MN and AUD. A 36%-higher mean-MRi in buccal cells (3.8+/-0.7) was found compared to lymphocytes (2.8+/-0.7)(P = 0.01). The meta-MRi in lymphocytes and buccal cells (1.7 and 3.0 respectively) suggest that buccal cells may be more sensitive. To assess their relative sensitivity, studies with measurements from the same subjects would be desirable. It is important that future studies (i) investigate, in well-designed powered studies, the prospective association of MN-formation with AUD and (ii) explore the molecular mechanisms by which chromosome shattering in MN and the release of chromatin fragments from MN lead to the formation of auto-antibodies.

Perinatal complications related to inherited thrombophilia: review of evidence in different regions of the world

The term thrombophilia describes disorders associated with an increased predisposition of developing venous thromboembolism (VTE). It may be acquired, like in those with antiphospholipid syndrome or inherited. The aim of this review was to compare the complications and outcomes of pregnancies in women with inherited thrombophilia between different populations, including the population of our country where the results of the research are scarce. The review of literature included all papers indexed on PubMed and Medline in the last 20 years, with different study design, including other reviews of literature, systematic reviews with meta-analysis and several case-control studies and population-based cohort studies. We aimed to cover as many geographic regions as possible with the aim to show the differences in the different parts of the world and including our country. Our analysis showed that types of thrombophilia differ in different geographic regions. Also, the differences exist between one particular type of thrombophilia in different regions. Nevertheless, no matter what the differences are between prevalence, all authors investigated the association between inherited thrombophilia and poor pregnancy outcome and managed to find some kind of association. The case with our own country is similar. Although we lack in studies with this issue and the design of published studies is not powerful enough, we may conclude that in our samples, women with thrombophilia are in potential risk of several poor pregnancy outcomes. Further and better analyses are necessary to prove this hypothesis not only on the level of study sample but also on general population. Given the fact that thrombophilia certainly affects the pregnancy and its outcome, the urge to perform screening tests in every woman suspected to have this kind of disorder and with respect to differences that exist in different world regions is inevitable.

Micronuclei and Their Association with Infertility, Pregnancy Complications, Developmental Defects, Anaemias, Inflammation, Diabetes, Chronic Kidney Disease, Obesity, Cardiovascular Disease, Neurodegenerative Diseases and Cancer

Micronuclei (MN) are a strong cytogenetic indicator of a catastrophic change in the genetic structure and stability of a cell because they originate from either chromosome breaks or whole chromosomes that have been lost from the main nucleus during cell division. The resulting genetic abnormalities can to lead to cellular malfunction, altered gene expression and impaired regenerative capacity. Furthermore, MN are increased as a consequence of genetic defects in DNA repair, deficiency in micronutrients required for DNA replication and repair and exposure to genotoxic chemicals and ultraviolet or ionising radiation. For all of these reasons, the measurement of MN has become one of the best-established methods to measure DNA damage in humans at the cytogenetic level. This chapter is a narrative review of the current evidence for the association of increased MN frequency with developmental and degenerative diseases. In addition, important knowledge gaps are identified, and recommendations for future studies required to consolidate the evidence are provided. The great majority of published studies show a significant association of increased MN in lymphocytes and/or buccal cells with infertility, pregnancy complications, developmental defects, anaemias, inflammation, diabetes, cardiovascular disease, kidney disease, neurodegenerative diseases and cancer. However, the strongest evidence is from prospective studies showing that MN frequency in lymphocytes predicts cancer risk and cardiovascular disease mortality.

Micronucleus Cytome Assays in Human Lymphocytes and Buccal Cells

The micronucleus (MN) assay, applied in different surrogate tissues, is one of the best validated cytogenetic techniques for evaluating chromosomal damage in humans. The cytokinesis-block micronucleus cytome assay in peripheral blood lymphocytes (L-CBMNcyt) is the most frequently used method in biomonitoring human populations to evaluate DNA damage caused by exposure to genotoxic agents, micronutrient deficiency or excess and genetic instability. Furthermore, recent scientific evidence suggests an association between an increased MN frequency in lymphocytes and risk of cancer and other age-related degenerative diseases. The micronucleus cytome assay applied in buccal exfoliated cells (BMNCyt), provides a complementary method for measuring DNA damage and cytotoxic effects in an easily accessible tissue not requiring ex vivo/in vitro culture. The protocol for L-CBMNcyt described here, refers to the use of ex vivo whole blood method, involving 72 h of culture with the block of cytokinesis starting at 44 h. BMNCyt protocol reports the established method for sample collection, processing, slide preparation and scoring.

The molecular origins and pathophysiological consequences of micronuclei: New insights into an age-old problem

Micronuclei (MN), the small nucleus-like bodies separated from the primary nucleus, can exist in cells with numerical and/or structural chromosomal aberrations in apparently normal tissues and more so in tumors in humans. While MN have been observed for over 100 years, they were merely and constantly considered as passive indicators of chromosome instability (CIN) for a long time. Relatively little is known about the molecular origins and biological consequences of MN. Rapid technological advances are helping to close these gaps. Very recent studies provide exciting evidence that MN act as key platform for chromothripsis and a trigger of innate immune response, suggesting that MN could affect cellular functions by both genetic and nongenetic means. These previously unappreciated findings have reawakened widespread interests in MN. In this review, the diverse mechanisms leading to MN generation and the complex fate profiles of MN are discussed, together with the evidence for their contribution to CIN, inflammation, senescence and cell death. Moreover, we put this knowledge together into a speculative perspective on how MN may be responsible for cancer development and how their presence may influence the choice of treatment. We suggest that the heterogeneous responses to MN may function physiological to ensure the arrestment, elimination and immune clearance of damaged cells, but pathologically, may enable the survival and oncogenic transformation of cells bearing CIN. These insights not only underscore the complexity of MN biology, but also raise a host of new questions and provide fertile ground for future research.

Cerium Oxide Nanoparticles Re-establish Cell Integrity Checkpoints and Apoptosis Competence in Irradiated HaCat Cells via Novel Redox-Independent Activity

Cerium oxide nanoparticles (CNPs) are potent radical scavengers protecting cells from oxidative insults, including ionizing radiation. Here we show that CNPs prevent X-ray-induced oxidative imbalance reducing DNA breaks on HaCat keratinocytes, nearly abating mutagenesis. At the same time, and in spite of the reduced damage, CNPs strengthen radiation-induced cell cycle arrest and apoptosis outcome, dropping colony formation; notably, CNPs do not possess any intrinsic toxicity toward non-irradiated HaCat, indicating that they act on damaged cells. Thus CNPs, while exerting their antioxidant action, also reinforce the stringency of damage-induced cell integrity checkpoints, promoting elimination of the “tolerant” cells, being in fact radio-sensitizers. These two contrasting pathways are mediated by different activities of CNPs: indeed Sm-doped CNPs, which lack the Ce³⁺/Ce⁴⁺ redox switch and the correlated antioxidant action, fail to decrease radiation-induced superoxide formation, as expected, but surprisingly maintain the radio-sensitizing ability and the dramatic decrease of mutagenesis. The latter is thus attributable to elimination of damaged cells rather than decreased oxidative damage. This highlights a novel redox-independent activity of CNPs, allowing selectively eliminating heavily damaged cells through non-toxic mechanisms, rather reactivating endogenous anticancer pathways in transformed cells.

Evaluation of DNA damage profile in obese women and its association to risk of metabolic syndrome, polycystic ovary syndrome and recurrent preeclampsia

Metabolic syndrome (MS) is a cluster of metabolic abnormalities. Obesity and MS are always accompanied by elevated oxidative stress which might affect cellular bio-molecules such as DNA. The aim of the present study is to investigate DNA damage profile in obese premenopausal women and its relation to the risk of MS, polycystic ovary syndrome (PCOS) and history of recurrent pre-eclampsia. The study included 90 obese women included cases with MS (n = 30), PCOS (n = 30) and previous history of recurrent preeclampsia (n = 30) and, age-matched healthy non-obese control women (n = 50). The assessment of leukocyte DNA damage was done by comet assay for all cases and controls. Anthropometry and biochemical parameters have been measured. Results showed that mean percent of DNA damage was significantly higher in MS, PCOS as well as in women with the recurrent preeclampsia as compared to healthy controls. The high level of mean DNA damage frequency in obese women was significantly associated with the increased number of metabolic syndrome components. Cases with 2, 3 and 3-5 components showed significantly higher levels of DNA damage than controls. Moreover, cases with 3-5 MS components showed significant higher DNA compared to those with the two components. Regarding PCOS, significant positive association between the mean frequency of DNA damage and waist circumference was observed. The study suggests that metabolic abnormalities, PCOS and recurrent pre-eclampsia might be contributed in development of DNA damage in obese women. DNA damage can serve as an early marker for obesity complications in premenopausal women.

Association Between Inherited Thrombophilia in Pregnancy and Micronucleus Frequency in Peripheral Blood Lymphocytes

The aim of this study was to determine possible predictors of an increased frequency of micronucleus (MN) and the impact of thrombophilia on the chromosomal instability in peripheral blood lymphocytes (PBL) of pregnant women in their first trimester. This study was designed as a case-control study on 74 pregnant women. It was performed in the gestational age of 11 to 14 weeks, when blood samples were collected and incubated for 72 hours. The individual MN frequency in PBL was measured by cytokinesis-block micronucleus (CBMN) assay. Women were grouped in control group [≤4 MN/1000 binucleated (BN) cells] and case group (>4 MN/1000 BN cells). Potential mutagenic effects of exogenous/endogenous factors in pregnant women were analyzed. By analyzing the given results, it can be concluded that pregnant women with thrombophilia have 26.69-times more chance of having a frequency of >4 MN/1000 BN than pregnant women with no thrombophilia. Our research was primarily aimed at showing that the presence of thrombophilia was a statistically important predictor of an increased MN frequency in pregnant women and it can predict about one-third of the total variance in MN frequency in the studied population.

Micronucleus, cell-free DNA, and plasma glycan composition in the newborns of healthy and diabetic mothers

Diabetes is associated with certain environmental exposures, heritable factors, and metabolic conditions of intrauterine development due to diabetes in the mother. We evaluated genomic damage, cell-free DNA, N-glycosylation of umbilical cord plasma proteins (PG), and nuclear division index (NDI) as possible prognostic biomarkers of health risk in the newborns of mothers with treated pregestational diabetes (NBDM; 22 mothers), compared these parameters with those from newborns of healthy mothers (NBHM; 89 mothers), and associated the results with the mothers' lifestyle in both groups, based on a detailed questionnaire. Genomic damage was estimated by the in vitro micronucleus (MN) assay. NDI was detected on MN slides. Glycans were analyzed by ultra-performance liquid chromatography that separates the plasma N-glycome into 46 glycan peaks. Cell-free DNA was analyzed by real-time PCR. For the association between biomarkers and individual characteristics, generalized linear/nonlinear analysis was performed. No significant difference was found between NBHM and NBDM for cell-free DNA levels. There was no association between cell-free DNA levels and lifestyle. MN frequency was significantly higher in NBDM than in NBHM (median, 0.6 vs. 0.3%, p<0.001). MN frequency and NDI were significantly associated with residence (urban vs. rural). PG differed significantly between NBHM and NBDM (p<0.001). A significant association was found between PG and increase of MN frequency (p<0.001). As both MN frequency and altered N-glycosylation are associated with cancer risk, our study indicates need for further investigations.

Utilização de biomarcadores de genotoxicidade e expressão gênica na avaliação de trabalhadores de postos de combustíveis expostos a vapores de gasolina

Resumo Introdução: a avaliação de uma exposição mensura sua intensidade, frequência e duração, podendo detectar danos precoces que, se ignorados, podem evoluir para um quadro nocivo. Nos campos da saúde ambiental e ocupacional, os biomarcadores de genotoxicidade tem sido largamente utilizados para essa avaliação. Objetivo: identificar, descrever e discutir os principais bioindicadores de genotoxicidade e seu uso conjunto com técnicas de avaliação de expressão gênica em estudos de exposição ocupacional ao benzeno em postos de revenda de combustíveis (PRC). Métodos: revisão bibliográfica de trabalhos publicados entre 1995 e 2015. Resultados: as técnicas identificadas foram: ensaio cometa, estresse oxidativo, micronúcleos, aberrações cromossômicas, polimorfismos, adutos de DNA e proteínas, fatores epigenéticos e expressão gênica. Foi observado que testes de danos genéticos e epigenéticos são utilizados em frentistas de PRC que participam de programas de saúde do trabalhador ou de pesquisas, embora um baixo número de publicações sobre o tema tenha sido identificado. Esse fato talvez possa ser explicado pelos poucos países onde a profissão persiste e pelas limitações para o desenvolvimento de pesquisas nesses países. Conclusão: os bioindicadores de genotoxicidade e as técnicas de expressão gênica são úteis na detecção de dano precoce desta exposição ocupacional e devem ser avaliados em conjunto.

Dynamics of Base Excision Repair at the Maternal-Fetal Interface in Pregnancies Complicated by Preeclampsia

Preeclampsia (PE) (gestational proteinuric hypertension) is the leading cause of maternal and perinatal mortality worldwide. Although placental endothelial dysfunction and oxidative stress are known to contribute to PE, the exact pathological basis for this disorder remains unclear. Previously, we demonstrated that DNA damage at the maternal-fetal interface is more common in the placentas of women with PE than normotensive controls. In this study, we utilized an in vivo comparative study, including 20 preeclamptic women and 8 healthy control subjects, and an in vitro hypoxia/reperfusion model to mimic the effects of oxidative stress at the maternal-fetal interface. We tracked the spatial pattern of expression of 2 base excision repair proteins, 8-oxoguanine glycosylase (OGG1) and apurinic/apyrimidinic endonuclease-1 (APE1), at the maternal-fetal interface in response to oxidative stress. In vivo, we found a significant increase in OGG1 and APE1 concentrations in PE placental tissues as compared to normotensive controls ( P < .0001). Further, our in vitro study revealed that OGG1 and APE1 expression is much greater in maternal cells (decidua) than in fetal cells (cytotrophoblasts) of placental tissue subjected to oxidative stress ( P < .0001). Our results suggest that OGG1 and APE1 likely protect decidual cells from oxidative base damage.

Identification of novel biomarkers for preeclampsia on the basis of differential expression network analysis

Preeclampsia (PE) is a severe pregnancy complication, which is a leading cause of maternal and fetal mortality. The present study aimed to screen potential biomarkers for the diagnosis and prediction of PE and to investigate the underlying mechanisms of PE development based on the differential expression network (DEN). The microarray datasets E-GEOD-6573 and E-GEOD-48424 were downloaded from the European Bioinformatics Institute database. Differentially expressed genes (DEGs) between the PE and normal groups were screened by Significant Analysis of Microarrays with the cutoff value of a |log2 fold change| of >2, and a false discovery rate of <0.05. The DEN was constructed based on the differential and non-differential interactions observed. In addition, genes with higher connectivity degrees in the DEN were identified on the basis of centrality analysis, while disease genes were also extracted from the DEN. In order to understand the functional roles of genes in DEN, Gene Ontology (GO) and pathway enrichment analyses were performed. The present results indicated that a total of 225 genes were considered as DEGs in the PE group, while 466 nodes and 314 gene interactions were involved in the DEN. Among these 466 nodes, 4 nodes with higher degrees were identified, including ubiquitin C (UBC), small ubiquitin-like modifier 1 (SUMO1), SUMO2 and RAD21 homolog (S. pombe) (RAD21). Notably, UBC was also found to be a disease gene. UBC, RAD21, SUMO2 and SUMO1 were markedly enriched in the regulation of programmed cell death, as well as in the regulation of apoptosis, cell cycle and chromosomal part. In conclusion, based on these results, we suggest that UBC, RAD21, SUMO2 and SUMO1 may be reliable biomarkers for the prediction of the development and progression of PE.

DNA Damage in Chronic Kidney Disease: Evaluation of Clinical Biomarkers

Patients with chronic kidney disease (CKD) exhibit an increased cancer risk compared to a healthy control population. To be able to estimate the cancer risk of the patients and to assess the impact of interventional therapies thereon, it is of particular interest to measure the patients' burden of genomic damage. Chromosomal abnormalities, reduced DNA repair, and DNA lesions were found indeed in cells of patients with CKD. Biomarkers for DNA damage measurable in easily accessible cells like peripheral blood lymphocytes are chromosomal aberrations, structural DNA lesions, and oxidatively modified DNA bases. In this review the most common methods quantifying the three parameters mentioned above, the cytokinesis-block micronucleus assay, the comet assay, and the quantification of 8-oxo-7,8-dihydro-2′-deoxyguanosine, are evaluated concerning the feasibility of the analysis and regarding the marker's potential to predict clinical outcomes.

Potential role of folate in pre-eclampsia

Dietary deficiencies of folate and other B vitamin cofactors involved in one-carbon metabolism, together with genetic polymorphisms in key folate-methionine metabolic pathway enzymes, are associated with increases in circulating plasma homocysteine, reduction in DNA methylation patterns, and genome instability events. All of these biomarkers have also been associated with pre-eclampsia. The aim of this review was to explore the literature and identify potential knowledge gaps in relation to the role of folate at the genomic level in either the etiology or the prevention of pre-eclampsia. A systematic search strategy was designed to identify citations in electronic databases for the following terms: folic acid supplementation AND pre-eclampsia, folic acid supplementation AND genome stability, folate AND genome stability AND pre-eclampsia, folic acid supplementation AND DNA methylation, and folate AND DNA methylation AND pre-eclampsia. Forty-three articles were selected according to predefined selection criteria. The studies included in the present review were not homogeneous, which made pooled analysis of the data very difficult. The present review highlights associations between folate deficiency and certain biomarkers observed in various tissues of women at risk of pre-eclampsia. Further investigation is required to understand the role of folate in either the etiology or the prevention of pre-eclampsia.

Mitigating the risk of radiation-induced cancers: limitations and paradigms in drug development

The United States radiation medical countermeasures (MCM) programme for radiological and nuclear incidents has been focusing on developing mitigators for the acute radiation syndrome (ARS) and delayed effects of acute radiation exposure (DEARE), and biodosimetry technologies to provide radiation dose assessments for guiding treatment. Because a nuclear accident or terrorist incident could potentially expose a large number of people to low to moderate doses of ionising radiation, and thus increase their excess lifetime cancer risk, there is an interest in developing mitigators for this purpose. This article discusses the current status, issues, and challenges regarding development of mitigators against radiation-induced cancers. The challenges of developing mitigators for ARS include: the long latency between exposure and cancer manifestation, limitations of animal models, potential side effects of the mitigator itself, potential need for long-term use, the complexity of human trials to demonstrate effectiveness, and statistical power constraints for measuring health risks (and reduction of health risks after mitigation) following relatively low radiation doses (<0.75 Gy). Nevertheless, progress in the understanding of the molecular mechanisms resulting in radiation injury, along with parallel progress in dose assessment technologies, make this an opportune, if not critical, time to invest in research strategies that result in the development of agents to lower the risk of radiation-induced cancers for populations that survive a significant radiation exposure incident.

HUMN project initiative and review of validation, quality control and prospects for further development of automated micronucleus assays using image cytometry systems

The use of micronucleus (MN) assays in in vitro genetic toxicology testing, radiation biodosimetry and population biomonitoring to study the genotoxic impacts of environment gene-interactions has steadily increased over the past two decades. As a consequence there has been a strong interest in developing automated systems to score micronuclei, a biomarker of chromosome breakage or loss, in mammalian and human cells. This paper summarises the outcomes of a workshop on this topic, organised by the HUMN project, at the 6th International Conference on Environmental Mutagenesis in Human Populations at Doha, Qatar, 2012. The aim of this paper is to summarise the outcomes of the workshop with respect to the set objectives which were: (i) Review current developments in automation of micronucleus assays by image cytometry; (ii) define the performance characteristics of automated MN scoring using image cytometry and methods of assessment for instrument validation and quality control and (iii) discuss the design of inter-laboratory comparisons and standardisation of micronucleus assays using automated image cytometry systems. It is evident that automated scoring of micronuclei by automated image cytometry using different commercially available platforms [e.g. Metafer (MetaSystems), Pathfinder™ (IMSTAR), iCyte(®) (Compucyte)], particularly for lymphocytes, is at a mature stage of development with good agreement between visual and automated scoring across systems (correlation factors ranging from 0.58 to 0.99). However, a standardised system of validation and calibration is required to enable more reliable comparison of data across laboratories and across platforms. This review identifies recent progress, important limitations and steps that need to be taken into account to enable the successful universal implementation of automated micronucleus assays by image cytometry.

Folate, vitamin B12, vitamin B6 and homocysteine: impact on pregnancy outcome

Good clinical practice recommends folic acid supplementation 1 month prior to pregnancy and during the first trimester to prevent congenital malformations. However, high rates of fetal growth and development in later pregnancy may increase the demand for folate. Folate and vitamins B12 and B6 are required for DNA synthesis and cell growth, and are involved in homocysteine metabolism. The primary aim of this study was to determine if maternal folate, vitamin B12, vitamin B6 and homocysteine concentrations at 18-20 weeks gestation are associated with subsequent adverse pregnancy outcomes, including pre-eclampsia and intrauterine growth restriction (IUGR). The secondary aim was to investigate maternal B vitamin concentrations with DNA damage markers in maternal lymphocytes. A prospective observational study was conducted at the Women's and Children's Hospital, Adelaide, South Australia. One hundred and thirty-seven subjects were identified prior to 20 weeks gestation as at high or low risk for subsequent adverse pregnancy outcome by senior obstetricians. Clinical status, dietary information, circulating micronutrients and genome damage biomarkers were assessed at 18-20 weeks gestation. Women who developed IUGR had reduced red blood cell (RBC) folate (P < 0.001) and increased plasma homocysteine concentrations (P < 0.001) compared with controls. Maternal DNA damage, represented by micronucleus frequency and nucleoplasmic bridges in lymphocytes, was positively correlated with homocysteine (r = 0.179, P = 0.038 and r = 0.171, P = 0.047, respectively). Multivariate regression analysis revealed RBC folate was a strong predictor of IUGR (P = 0.006). This study suggests that low maternal RBC folate and high homocysteine values in mid pregnancy are associated with subsequent reduced fetal growth.

DNA damage and health in pregnancy

In healthy pregnancy reactive oxygen species and antioxidants remain in balance and DNA damage is repaired effectively. However, pregnancy is an inflammatory state exhibiting increased susceptibility to oxidative stress such that this balance can be easily disrupted. Increased DNA damage has been shown to be involved in many pathological states including pregnancy complications. Modern lifestyles including exposure to pollutants, poor diet, and lack of exercise cause excess inflammation, oxidative stress, and ultimately DNA damage. There is a growing body of literature providing evidence that these lifestyle changes are increasing our risk of infertility, miscarriage, and late-gestation pregnancy complications. Moreover, baseline DNA damage rises with age and couples in developed societies are delaying childbirth, placing them at further risk. In order to understand the effect of lifestyle and DNA damage on pregnancy health we require large prospective studies, with the collection of samples prior to conception and endpoints of time-to-pregnancy, early pregnancy loss, and late-gestation maternal and fetal health.

Micronuclei and their association with sperm abnormalities, infertility, pregnancy loss, pre-eclampsia and intra-uterine growth restriction in humans

The micronucleus (MN) assay is increasingly being used to study the association between DNA damage and infertility or pregnancy complications in humans. This review provides a brief overview of the studies published to date. The results of these studies appear to support the plausibility of the following hypotheses: (i) MN in spermatids in semen may be indicative of infertility risk, (ii) MN in peripheral blood lymphocytes in males correlate positively with DNA damage in sperm, (iii) infertile couples exhibit higher frequencies of MN than fertile couples and (iv) an abnormally high frequency of MN in peripheral blood lymphocytes is associated with pregnancy complications including miscarriage, intra-uterine growth restriction and pre-eclampsia. The studies published to date consistently indicate an association of MN in peripheral blood lymphocytes with impaired reproductive capacity. However, the conclusions of these studies, although statistically significant, are limited by small sample sizes and the need for verification in other independent cohorts. In conclusion, more attention should be given to the possibility of using MN assays in peripheral blood lymphocytes and reproductive tissues as a biomarker of risk for infertility and pregnancy complications in humans.