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Environmental Science & Technology Oct 2023Polycyclic aromatic hydrocarbon (PAH) derivatives constitute a significant class of emerging contaminants that have been ubiquitously detected in diverse environmental... (Review)
Review
Polycyclic aromatic hydrocarbon (PAH) derivatives constitute a significant class of emerging contaminants that have been ubiquitously detected in diverse environmental matrixes, with some even exhibiting higher toxicities than their corresponding parent PAHs. To date, compared with parent PAHs, fewer systematic summaries and reanalyses are available for PAH derivatives with great environmental concerns. This review summarizes the current knowledge on the chemical species, levels, biotransformation patterns, chemical analytical methods, internal exposure routes with representative biomarkers, and toxicity of PAH derivatives, primarily focusing on nitrated PAHs (NPAHs), oxygenated PAHs (OPAHs), halogenated PAHs (XPAHs), and alkylated PAHs (APAHs). A collection of 188 compounds from four categories, 44 NPAHs, 36 OPAHs, 56 APAHs, and 52 XPAHs, has been compiled from 114 studies that documented the environmental presence of PAH derivatives. These compounds exhibited weighted average air concentrations that varied from a lower limit of 0.019 pg/m to a higher threshold of 4060 pg/m. Different analytical methods utilizing comprehensive two-dimensional gas chromatography coupled with high-resolution time-of-flight mass spectrometry (GC × GC-TOF-MS), gas chromatography coupled to time-of-flight mass spectrometry (GC-TOF-MS), comprehensive two-dimensional gas chromatography coupled to quadrupole mass spectrometry (GC × GC-QQQ-MS), and Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS), that adopted untargeted strategies for the identification of PAH derivatives are also reviewed here. Additionally, an in-depth analysis of biotransformation patterns for each category is provided, including the likelihood of specific biotransformation reaction types. For the toxicity, we primarily summarized key metabolic activation pathways, which could result in the formation of reactive metabolites capable of covalently bonding with DNA and tissue proteins, and potential health outcomes such as carcinogenicity and genotoxicity, oxidative stress, inflammation and immunotoxicity, and developmental toxicity that might be mediated by the aryl hydrocarbon receptor (AhR). Finally, we pinpoint research challenges and emphasize the need for further studies on identifying PAH derivatives, tracking external exposure levels, evaluating internal exposure levels and associated toxicity, clarifying exposure routes, and considering mixture exposure effects. This review aims to provide a broad understanding of PAH derivatives' identification, environmental occurrence, human exposure, biotransformation, and toxicity, offering a valuable reference for guiding future research in this underexplored area.
PubMed: 37703436
DOI: 10.1021/acs.est.3c03170 -
Neuroscience and Biobehavioral Reviews May 2020DNA methylation (DNAm) - an epigenetic process that regulates gene expression - may represent a mechanism for the biological embedding of early traumatic experiences,...
DNA methylation (DNAm) - an epigenetic process that regulates gene expression - may represent a mechanism for the biological embedding of early traumatic experiences, including childhood maltreatment. Here, we conducted the first systematic review of human studies linking childhood maltreatment to DNAm. In total, 72 studies were included in the review (2008-2018). The majority of extant studies (i) were based on retrospective data in adults, (ii) employed a candidate gene approach (iii) focused on global maltreatment, (iv) were based on easily accessible peripheral tissues, typically blood; and (v) were cross-sectional. Two-thirds of studies (n = 48) also examined maltreatment-related outcomes, such as stress reactivity and psychiatric symptoms. While findings generally support an association between childhood maltreatment and altered patterns of DNAm, factors such as the lack of longitudinal data, low comparability across studies as well as potential genetic and 'pre-exposure' environmental confounding currently limit the conclusions that can be drawn. Key challenges are discussed and concrete recommendations for future research are provided to move the field forward.
Topics: Adult Survivors of Child Abuse; Adverse Childhood Experiences; DNA Methylation; Epigenesis, Genetic; Humans; Mental Disorders
PubMed: 32081689
DOI: 10.1016/j.neubiorev.2020.02.019 -
The interplay between DNA methylation and cardiac autonomic system functioning: a systematic review.International Journal of Environmental... Jan 2023Epigenetic marks, particularly DNA methylation (DNAm), are emerging as an important biological marker of susceptibility to cardiac autonomic dysfunction. This review... (Review)
Review
Epigenetic marks, particularly DNA methylation (DNAm), are emerging as an important biological marker of susceptibility to cardiac autonomic dysfunction. This review summarizes recent discoveries about the association between DNAm and cardiac autonomic activity. A systematic literature search was performed through the Embase, Web of Science, Cochrane Library, Pubmed, PsycINFO, and Pilots databases. Twenty-two studies met inclusion criteria, of which 18 were human studies including a total of 2,686 participants. DNAm differences in multiple genes, such as , and , linked environmental stressors to physiological responses. For instance, exposure to psychosocial stressors increased methylation, which was associated with both decreased blood pressure and increased parasympathetic activity. Additionally, played a potential role in cardiac autonomic dysfunction in an occupational setting, affecting the heart rate's deceleration capacity in welders. This review's findings suggest that DNAm is involved in cardiac autonomic regulation under different stress-mediated responses.
Topics: Humans; DNA Methylation; Autonomic Nervous System; Biomarkers
PubMed: 34753378
DOI: 10.1080/09603123.2021.2000590 -
Human Reproduction Update Nov 2020Studies in non-human mammals suggest that environmental factors can influence spermatozoal DNA methylation, and some research suggests that spermatozoal DNA methylation...
BACKGROUND
Studies in non-human mammals suggest that environmental factors can influence spermatozoal DNA methylation, and some research suggests that spermatozoal DNA methylation is also implicated in conditions such as subfertility and imprinting disorders in the offspring. Together with an increased availability of cost-effective methods of interrogating DNA methylation, this premise has led to an increasing number of studies investigating the DNA methylation landscape of human spermatozoa. However, how the human spermatozoal DNA methylome is influenced by environmental factors is still unclear, as is the role of human spermatozoal DNA methylation in subfertility and in influencing offspring health.
OBJECTIVE AND RATIONALE
The aim of this systematic review was to critically appraise the quality of the current body of literature on DNA methylation in human spermatozoa, summarize current knowledge and generate recommendations for future research.
SEARCH METHODS
A comprehensive literature search of the PubMed, Web of Science and Cochrane Library databases was conducted using the search terms 'semen' OR 'sperm' AND 'DNA methylation'. Publications from 1 January 2003 to 2 March 2020 that studied human sperm and were written in English were included. Studies that used sperm DNA methylation to develop methodologies or forensically identify semen were excluded, as were reviews, commentaries, meta-analyses or editorial texts. The Grading of Recommendations, Assessment, Development and Evaluations (GRADE) criteria were used to objectively evaluate quality of evidence in each included publication.
OUTCOMES
The search identified 446 records, of which 135 were included in the systematic review. These 135 studies were divided into three groups according to area of research; 56 studies investigated the influence of spermatozoal DNA methylation on male fertility and abnormal semen parameters, 20 studies investigated spermatozoal DNA methylation in pregnancy outcomes including offspring health and 59 studies assessed the influence of environmental factors on spermatozoal DNA methylation. Findings from studies that scored as 'high' and 'moderate' quality of evidence according to GRADE criteria were summarized. We found that male subfertility and abnormal semen parameters, in particular oligozoospermia, appear to be associated with abnormal spermatozoal DNA methylation of imprinted regions. However, no specific DNA methylation signature of either subfertility or abnormal semen parameters has been convincingly replicated in genome-scale, unbiased analyses. Furthermore, although findings require independent replication, current evidence suggests that the spermatozoal DNA methylome is influenced by cigarette smoking, advanced age and environmental pollutants. Importantly however, from a clinical point of view, there is no convincing evidence that changes in spermatozoal DNA methylation influence pregnancy outcomes or offspring health.
WIDER IMPLICATIONS
Although it appears that the human sperm DNA methylome can be influenced by certain environmental and physiological traits, no findings have been robustly replicated between studies. We have generated a set of recommendations that would enhance the reliability and robustness of findings of future analyses of the human sperm methylome. Such studies will likely require multicentre collaborations to reach appropriate sample sizes, and should incorporate phenotype data in more complex statistical models.
Topics: DNA Methylation; Female; Humans; Infertility, Male; Male; Pregnancy; Pregnancy Outcome; Reproducibility of Results; Semen; Spermatozoa
PubMed: 32790874
DOI: 10.1093/humupd/dmaa025 -
Journal of Thoracic Oncology : Official... Sep 2021Malignant mesothelioma is an aggressive cancer type linked to asbestos exposure. Because of several intrinsic challenges, mesothelioma is often diagnosed in an advanced... (Meta-Analysis)
Meta-Analysis Review
Malignant mesothelioma is an aggressive cancer type linked to asbestos exposure. Because of several intrinsic challenges, mesothelioma is often diagnosed in an advanced disease stage. Therefore, there is a need for diagnostic biomarkers that may contribute to early detection. Recently, the epigenome of tumors is being extensively investigated to identify biomarkers. This manuscript is a systematic review summarizing the state-of-the-art research investigating DNA methylation in mesothelioma. Four literature databases (PubMed, Scopus, Web of Science, MEDLINE) were systematically searched for studies investigating DNA methylation in mesothelioma up to October 16, 2020. A meta-analysis was performed per gene investigated in at least two independent studies. A total of 53 studies investigated DNA methylation of 97 genes in mesothelioma and are described in a qualitative overview. Furthermore, ten studies investigating 13 genes (APC, CDH1, CDKN2A, DAPK, ESR1, MGMT, miR-34b/c, PGR, RARβ, RASSF1, SFRP1, SFRP4, WIF1) were included in the quantitative meta-analysis. In this meta-analysis, the APC gene is significantly hypomethylated in mesothelioma, whereas CDH1, ESR1, miR-34b/c, PGR, RARβ, SFRP1, and WIF1 are significantly hypermethylated in mesothelioma. The three genes that are the most appropriate candidate biomarkers from this meta-analysis are APC, miR-34b/c, and WIF1. Nevertheless, both study number and study objects comprised in this meta-analysis are too low to draw final conclusions on their clinical applications. The elucidation of the genome-wide DNA methylation profile of mesothelioma is desirable in the future, using a standardized genome-wide methylation analysis approach. The most informative CpG sites from this signature could then form the basis of a panel of highly sensitive and specific biomarkers that can be used for the diagnosis of mesothelioma and even for the screening of an at high-risk population of asbestos-exposed individuals.
Topics: Asbestos; Biomarkers, Tumor; DNA Methylation; Humans; Lung Neoplasms; Mesothelioma; Mesothelioma, Malignant
PubMed: 34082107
DOI: 10.1016/j.jtho.2021.05.015 -
Neuroscience and Biobehavioral Reviews Nov 2020Childhood socioeconomic position (SEP) is associated with the development of adult psychological outcomes, with DNA methylation (DNAm) as a mechanism to potentially... (Review)
Review
Childhood socioeconomic position (SEP) is associated with the development of adult psychological outcomes, with DNA methylation (DNAm) as a mechanism to potentially explain these changes. We present the first systematic review synthesising the literature investigating childhood SEP and DNAm. Thirty-two publications were included. Seventeen studies focused on candidate genes, typically focusing on genes implicated with the stress response and/or development of psychiatric conditions. These studies typically investigated different regions of the genes, which revealed inconsistent results. Six studies calculated epigenetic age, with a small number revealing an elevated significant association with childhood SEP. Epigenome-wide studies revealed altered patterns of DNAm which varied between the nine studies. This research area is emerging and demonstrated great variance in findings with no clear patterns identified across studies. Multiple methodological shortcomings are identified, including at the phenotypic level where construct validity of childhood SEP is highly inconsistent, with studies using a wide range of measures. Larger cohorts will be required with international collaborations to strengthen this research area.
Topics: Adult; Cicatrix; DNA Methylation; Epigenome; Epigenomics; Humans; Socioeconomic Factors
PubMed: 32795493
DOI: 10.1016/j.neubiorev.2020.08.001 -
Noise & Health 2020Noise-induced hearing loss (NIHL) is one of the leading causes of acquired sensorineural hearing loss. However, molecular mechanisms responsible for its pathogenesis...
BACKGROUND
Noise-induced hearing loss (NIHL) is one of the leading causes of acquired sensorineural hearing loss. However, molecular mechanisms responsible for its pathogenesis remain to be elucidated. Epigenetic changes, i.e. DNA methylation, histone and microRNA expression modifications may function as a link between noise exposure and hearing loss. Therefore, the aim of the present review was to assess whether epigenetic alterations may serve as biomarkers of noise exposure or early effect.
MATERIALS AND METHODS
A systematic review of studies available in Pubmed, Scopus, and ISI Web of Science databases was performed.
RESULTS
Noise exposure was able to induce alterations in DNA methylation levels in workers and animal models, resulting in expression changes of genes related to hearing loss and also to extra-auditory effects. Differently expressed microRNAs were determined in NIHL workers compared to noise-exposed subjects with normal hearing, supporting their possible role as biomarkers of effect. Acoustic trauma affected histon acethylation and methylation levels in animals, suggesting their influence in the pathogenesis of acute noise-induced damage and their role as targets for potential therapeutic treatments.
CONCLUSIONS
Although preliminary data suggest a relationship between noise and epigenetic effects, the limited number of studies, their different methodologies and the lack of adequate characterization of acoustic insults prevent definite conclusions. In this context, further research aimed to define the epigenetic impact of workplace noise exposure and the role of such alterations in predicting hearing loss may be important for the adoption of correct risk assessment and management strategies in occupational settings.
Topics: Animals; DNA Methylation; Environmental Exposure; Epigenesis, Genetic; Genetic Markers; Hearing Loss, Noise-Induced; Histones; Humans; MicroRNAs; Noise; Occupational Diseases; Risk Assessment
PubMed: 33402608
DOI: 10.4103/nah.NAH_17_20 -
Schizophrenia Research Aug 2022Evidence suggests that schizophrenia (SZ) is associated with accelerated biological aging. DNA methylation can be used as an indicator of biological aging by means of... (Meta-Analysis)
Meta-Analysis
INTRODUCTION
Evidence suggests that schizophrenia (SZ) is associated with accelerated biological aging. DNA methylation can be used as an indicator of biological aging by means of epigenetic clock estimates.
OBJECTIVE
The aim of this systematic review and meta-analysis was to investigate the association between SZ and different epigenetic clocks.
METHODS
Search terms were applied in different databases: Embase, MEDLINE (EBSCO), Cochrane Central Register of Controlled Trials, PubMed, PsychINFO and Web of Science. To assess for risk of bias we utilized an adapted version of the Newcastle-Ottawa Scale. Meta-analyses were conducted using the random effects model and meta-regressions were used to assess factors associated with heterogeneity.
RESULTS
Eight studies were included (Controls, n = 3394; SZ subjects, n = 3096), which analyzed five different epigenetic clocks. Overall meta-analysis revealed no significant differences between SZ and controls on epigenetic aging (Standardized Mean Difference - SMD = -0.21; p = 0.13). However, epigenetic clock method was a significant moderator of heterogeneity (p = 0.004). Using Horvath's clock as reference, higher SMD's were found for PhenoAge and Intrinsic epigenetic age acceleration (IEAA) clocks. In a stratified meta-analysis restricted to the two clocks mentioned above, a significant accelerating effect was found in patients with SZ when compared to controls (SMD = 0.29; p = 0.003).
CONCLUSION
Our findings suggest that the method of epigenetic clocks is a critical factor associated with estimates of aging acceleration in SZ. However, more studies are needed to confirm these findings and in order to evaluate a possible minor effect in overall analysis.
Topics: Aging; DNA Methylation; Epigenesis, Genetic; Epigenomics; Humans; Schizophrenia
PubMed: 35780750
DOI: 10.1016/j.schres.2022.06.029 -
Clinical Epigenetics Jul 2023To systematically evaluate the efficacy and safety of FDA-approved isocitrate dehydrogenase (IDH) inhibitors in the treatment of IDH-mutated acute myeloid leukemia (AML). (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
To systematically evaluate the efficacy and safety of FDA-approved isocitrate dehydrogenase (IDH) inhibitors in the treatment of IDH-mutated acute myeloid leukemia (AML).
METHODS
We used R software to conduct a meta-analysis of prospective clinical trials of IDH inhibitors in the treatment of IDH-mutated AML published in PubMed, Embase, Clinical Trials, Cochrane Library and Web of Science from inception to November 15th, 2022.
RESULTS
A total of 1109 IDH-mutated AML patients from 10 articles (11 cohorts) were included in our meta-analysis. The CR rate, ORR rate, 2-year survival (OS) rate and 2-year event-free survival (EFS) rate of newly diagnosed IDH-mutated AML (715 patients) were 47%, 65%, 45% and 29%, respectively. The CR rate, ORR rate, 2-year OS rate, median OS and median EFS of relapsed or refractory (R/R) IDH-mutated AML (394 patients) were 21%, 40%, 15%, 8.21 months and 4.73 months, respectively. Gastrointestinal adverse events were the most frequently occurring all-grade adverse events and hematologic adverse events were the most frequently occurring ≥ grade 3 adverse events.
CONCLUSION
IDH inhibitor is a promising treatment for R/R AML patients with IDH mutations. For patients with newly diagnosed IDH-mutated AML, IDH inhibitors may not be optimal therapeutic agents due to low CR rates. The safety of IDH inhibitors is controllable, but physicians should always pay attention to and manage the differentiation syndrome adverse events caused by IDH inhibitors. The above conclusions need more large samples and high-quality RCTs in the future to verify.
Topics: Humans; Prospective Studies; DNA Methylation; Leukemia, Myeloid, Acute; Enzyme Inhibitors; Mutation
PubMed: 37434249
DOI: 10.1186/s13148-023-01529-2 -
Biomarkers : Biochemical Indicators of... Sep 2023Colorectal cancer (CRC) poses a substantial health burden, with early detection paramount for improved prognosis. This study aims to evaluate potential CRC biomarkers...
INTRODUCTION
Colorectal cancer (CRC) poses a substantial health burden, with early detection paramount for improved prognosis. This study aims to evaluate potential CRC biomarkers and detection techniques.
MATERIALS AND METHODS
This systematic review, reported in adherence to PRISMA Statement 2020 guidelines, collates the latest research on potential biomarkers and detection/prognosis methods for CRC, spanning the last decade.
RESULTS
Out of the 38 included studies, diverse biomarkers and detection methods emerged, with DNA methylation markers like SFRP2 and SDC2, microRNAs including miR-1290, miR-506, and miR-4316, and serum and plasma markers such as NTS levels and U2 snRNA fragments standing out. Methylated cfDNA and m5C methylation alteration in immune cells of the blood, along with circular RNA, showed promise as diagnostic markers. Meanwhile, techniques involving extracellular vesicles and lateral flow immunoassays exhibited potential for swift and effective CRC screening.
DISCUSSION
Our state-of-the-art review identifies potential biomarkers, including SFRP2, SDC2, miR-1290, miR-506, miR-4316, and U2 snRNA fragments, with significant potential in enhancing CRC detection. However, comprehensive validation studies and a rigorous evaluation of clinical utility and cost-effectiveness remain necessary before integration into routine clinical practice.
CONCLUSION
The findings emphasize the need for continued research into biomarkers and detection methods to improve patient outcomes.
Topics: Humans; DNA Methylation; Biomarkers, Tumor; MicroRNAs; Prognosis; Early Detection of Cancer; Colorectal Neoplasms
PubMed: 37585692
DOI: 10.1080/1354750X.2023.2247185