What are the DNA lesions underlying formaldehyde toxicity?

A critical review on ocean acidification driven by disinfection by-products discharge from ships' ballast water management systems: Impacts on carbon chemistry

The world's blue economy is closely tied to maritime trade, but ballast water from ships often carries harmful aquatic organisms and pathogens, which disrupt the marine environment. To address this, the International Maritime Organization (IMO) mandated ballast water treatment to eradicate these invasive species. However, the treatment processes inherently generate numerous Disinfection by-Products (DBPs). The discharge of these DBPs exacerbates ocean acidification through various acid- and CO2-releasing reactions. The IMO's Ballast Water Working Group has listed 41 high-priority DBPs for risk assessment due to their toxicity and prevalence in treated ballast water. This review quantitatively evaluates changes in pH and carbonate ions in seawater using the PyCO2SYS software package. Results reveal that DBPs can reduce ocean pH by ∼0.057 units and carbonate ion concentrations by 24.06 μmol kg-1 during a single discharge of 1 m3 treated water. In addition, this review outlines the challenges and research gaps for marine ecosystems sustainability.

Unveiling the nexus between environmental exposures and testicular damages: revelations from autophagy and oxidative stress imbalance

Recent evidence consolidates the deleterious impact of environmental exposure on testicular damage. Environmental exposures can instigate testicular toxicity, causing damage to the Sertoli-Sertoli cell-mediated blood-testis barrier (BTB) integrity, alterations in hormone levels orchestrated by aberrant Leydig cells, and disruption of spermatogenesis. Despite diverse study designs and methodologies, a consensus is emerging on how environmental factors induce oxidative stress by elevating ROS levels, affecting autophagy through pathways such as the ROS-mediated mTOR signaling pathway, ultimately culminating in testicular damage. This review synthesizes existing literature on how environmental exposures, including metals, air pollutants, industrial contaminants, and pesticides, disturb testicular homeostasis via autophagy-mediated oxidative stress, highlighting recent significant advancements. It also explores interventions like antioxidant support and autophagy regulation to alleviate testicular damage. These findings underscore the importance of elucidating the mechanisms of autophagy influenced by environmental exposures in disrupting the equilibrium of oxidative stress, identifying potential drug targets, and establishing a groundwork for enhancing future treatments and clinical management of testicular injuries.

From aldehyde metabolism to delay aging: targeting ALDH2 as a novel strategy

Aldehydes are molecules that are commonly found in both human physiology and the environment. The accumulation of these substances can lead to the cross-linking of intracellular DNA and proteins, thereby disrupting cellular function and contributing to the processes of premature aging and age-related diseases. Aldehyde dehydrogenase 2 (ALDH2), the key member of ALDH family, is an enzyme responsible for aldehyde metabolism, composed of four identical subunits located within the mitochondrial matrix. Its primary role is to catalyze the oxidation of aldehydes, resulting in the formation of their corresponding acid metabolites. This paper presents a succinct overview of the sources and metabolic pathways of key aldehydes within the human body, compares the various primary enzymes involved in aldehyde metabolism, and explores the structural and functional characteristics of ALDH2. Furthermore, ALDH2 is proposed as a potential therapeutic target for addressing aging and associated diseases. The discussion also includes prospective research avenues, particularly focusing on ALDH2 agonists and aldehyde scavengers designed to enhance the clearance of reactive aldehydes and safeguard cellular functions, thereby mitigating aldehyde-induced cellular damage and potentially delaying the aging process.

The impact of genetic polymorphism for detecting genotoxicity in workers occupationally exposed to formaldehyde: A systematic review

Formaldehyde is a chemical compound capable of preserving cells and tissue morphology, being extensively used worldwide in industrial and medical processes. However, due to the many biological effects that take place after an individual is chronically exposed to formaldehyde, this compound poses a greater cancer risk for workers under its occupational exposure, even at lower concentrations. Thus, the present systematic review aimed to understand whether there may be a positive relation between polymorphism (in terms of individual susceptibility) and genotoxicity in individuals occupationally exposed to formaldehyde. For this purpose, a total of eight selected studies were carefully analyzed by two reviewers, who attributed scores to each study according to the used analysis parameters. First, all studies investigated either pathologists under formaldehyde exposure or anatomical laboratory pathology workers. In addition, the majority of studies were categorized as moderate or strong in the quality assessment. The results revealed a positive association between some polymorphism and genotoxicity in individuals exposed to formaldehyde, since more than half of the studies observed positive relations between genotoxicity and polymorphisms in xenobiotics metabolizing genes. We understand such parameters influence individuals' susceptibility to genomic damage induced by formaldehyde in peripheral blood. In conclusion, individuals with certain genotypes may show higher or lower DNA damage and/or lower or higher DNA repair potential.

Repair of genomic interstrand crosslinks

Genomic interstrand crosslinks (ICLs) are formed by reactive species generated during normal cellular metabolism, produced by the microbiome, and employed in cancer chemotherapy. While there are multiple options for replication dependent and independent ICL repair, the crucial step for each is unhooking one DNA strand from the other. Much of our insight into mechanisms of unhooking comes from powerful model systems based on plasmids with defined ICLs introduced into cells or cell free extracts. Here we describe the properties of exogenous and endogenous ICL forming compounds and provide an historical perspective on early work on ICL repair. We discuss the modes of unhooking elucidated in the model systems, the concordance or lack thereof in drug resistant tumors, and the evolving view of DNA adducts, including ICLs, formed by metabolic aldehydes.

Introducing the Role of Genotoxicity in Neurodegenerative Diseases and Neuropsychiatric Disorders

Decades of research have identified genetic and environmental factors involved in age-related neurodegenerative diseases and, to a lesser extent, neuropsychiatric disorders. Genomic instability, i.e., the loss of genome integrity, is a common feature among both neurodegenerative (mayo-trophic lateral sclerosis, Parkinson's disease, Alzheimer's disease) and psychiatric (schizophrenia, autism, bipolar depression) disorders. Genomic instability is associated with the accumulation of persistent DNA damage and the activation of DNA damage response (DDR) pathways, as well as pathologic neuronal cell loss or senescence. Typically, DDR signaling ensures that genomic and proteomic homeostasis are maintained in both dividing cells, including neural progenitors, and post-mitotic neurons. However, dysregulation of these protective responses, in part due to aging or environmental insults, contributes to the progressive development of neurodegenerative and/or psychiatric disorders. In this Special Issue, we introduce and highlight the overlap between neurodegenerative diseases and neuropsychiatric disorders, as well as the emerging clinical, genomic, and molecular evidence for the contributions of DNA damage and aberrant DNA repair. Our goal is to illuminate the importance of this subject to uncover possible treatment and prevention strategies for relevant devastating brain diseases.