A molecular switch hidden in RNA is emerging as a crucial link between environmental pollution, brain development and neurodegenerative disease, according to a new review published in Genes & Diseases. The review examines how N6-methyladenosine, commonly known as m6A, may help explain why exposure to certain metals and chemicals can disrupt the nervous system long after the initial toxic insult. Unlike mutations that permanently alter DNA, m6A is a reversible chemical mark added to RNA molecules. By changing how RNA is processed, transported, translated into proteins or degraded, it can rapidly reshape cell behavior without changing the underlying genetic code.
RNA carries instructions copied from DNA, but those instructions do not automatically determine how a cell functions. Messenger RNA must be stabilized, transported and translated at the right time and in the right amount. m6A modification acts as part of this regulatory system. Specialized proteins known as “writers” add the methyl group to RNA, “erasers” remove it, and “readers” recognize the mark and determine what happens to the modified molecule. This dynamic network is particularly important in the developing brain, where neural stem cells must produce different types of neurons and glial cells in precise sequences.
During brain development, balanced m6A activity helps control whether neural stem cells continue dividing, remain in an undifferentiated state or mature into specialized cells. It also influences the formation of neuronal connections, the production of myelin and the activity of immune cells in the nervous system. These processes depend on carefully timed changes in gene expression. If RNA molecules are stabilized for too long, destroyed too quickly or translated inefficiently, the consequences can include abnormal neural development, impaired communication between neurons and reduced resilience to later damage.
The review describes evidence that disrupted m6A regulation is associated with several neurological disorders, including Alzheimer’s disease, Parkinson’s disease and epilepsy. In these conditions, abnormal RNA methylation may affect pathways involved in neuronal survival, synaptic plasticity, inflammation, oxidative stress and the accumulation of misfolded proteins. In Alzheimer’s disease, for example, altered m6A signaling has been linked to mechanisms associated with memory impairment and pathological protein deposition. In Parkinson’s disease, the same regulatory system may influence the vulnerability of dopamine-producing neurons and the inflammatory responses that contribute to their loss.
The connection between m6A and environmental toxicants is especially significant because the chemicals discussed in the review act through different biological pathways. Manganese exposure can interfere with mitochondrial function and neuronal signaling, while arsenite can trigger oxidative stress and damage proteins involved in cellular defense. Aluminum has been investigated for its potential effects on inflammation and protein homeostasis, and cobalt can alter cellular responses to oxygen availability and metabolic stress. The anesthetic sevoflurane, meanwhile, has been studied for possible effects on developing brains, particularly in relation to inflammation, neuronal survival and cognitive function. The review brings these apparently different hazards together through their potential impact on RNA regulation.
Toxicants may disturb the m6A system by changing the activity or abundance of methylation “writers,” demethylation “erasers” or RNA-binding “readers.” They may also alter the cellular environment in which these proteins operate. Oxidative stress, disrupted energy production, abnormal immune signaling and changes in cellular metabolism can all influence RNA modification. Because m6A controls many RNA molecules at once, even a modest disturbance could affect multiple biological systems, including synaptic function, neurodevelopment, inflammatory signaling and the brain’s ability to repair itself.
This mechanism may also help explain why the timing of exposure matters. A toxicant encountered during early development could interfere with neural stem-cell decisions or the establishment of neural circuits, potentially producing effects that become visible only later in life. Exposure in adulthood may instead accelerate inflammation, impair neuronal maintenance or reduce the brain’s ability to respond to injury. The review emphasizes that m6A is not simply a marker of damage; it may be part of the process through which environmental stress is translated into long-term changes in nervous-system function.
The findings point toward possible therapeutic strategies, although they remain at an early stage. Drugs designed to adjust the activity of m6A writers or erasers could, in principle, restore healthier patterns of RNA regulation. Modifying reader proteins might alter the fate of specific RNA molecules without changing the entire methylation system. Another approach involves exosomes, naturally occurring membrane-bound particles that transport RNA and proteins between cells. Because some exosomes can cross the blood-brain barrier, researchers are investigating whether they could deliver protective molecules or RNA-based therapies to vulnerable regions of the central nervous system.
The authors caution that the relationship between m6A, toxicant exposure and neurological disease is complex. The effects of RNA methylation can vary according to cell type, developmental stage, exposure level and the specific RNA molecules involved. A change that protects one population of cells could be harmful in another, and results observed in experimental models may not directly predict human outcomes. More research is needed to identify reliable biomarkers of toxicant-related RNA disruption, determine whether m6A changes are a cause or consequence of disease, and establish treatments that can act on the pathway safely.
By connecting environmental toxicology with epitranscriptomics—the study of chemical changes that regulate RNA—the review offers a broader framework for understanding how external exposures can influence brain health. m6A may ultimately become useful both as an indicator of neurological stress and as a target for intervention. For now, the emerging evidence suggests that the consequences of toxicant exposure are written not only in damaged cells or altered DNA, but also in the constantly changing chemical instructions carried by RNA.
Subject of Research: The role of N6-methyladenosine (m6A) RNA modification in neural development and toxicant-related neurodegeneration.
Article Title: Interaction between N6-methyladenosine (m6A) modification and toxicant-related neurodegeneration: From neural development to pathophysiology
Web References: https://doi.org/10.1016/j.gendis.2025.101984
References: Zhou She, Peng Huang, Senlin Luo, Lu Zhang, Hong Peng, Yufen Tang, Yuqiong Chen, Jinwen Luo, Wangxin Duan, Lingjuan Liu, Liqun Liu, “Interaction between N6-methyladenosine (m6A) modification and toxicant-related neurodegeneration: From neural development to pathophysiology,” Genes & Diseases, Volume 13, Issue 5, 2026, Article 101984.
Image Credits: Genes & Diseases
Keywords: m6A RNA methylation, epitranscriptomics, RNA modification, brain development, neural stem cells, neurodegeneration, environmental toxicants, manganese, arsenite, aluminum, cobalt, sevoflurane, Alzheimer’s disease, Parkinson’s disease, epilepsy, exosomes, blood-brain barrier.
Tags: ” “erasers” and “readers” epitranscriptomic regulation in neural developmentenvironmental pollution and brain developmentenvironmental toxins affecting RNA modificationimpact of metals and chemicals on nervous systemN6-methyladenosine (m6A) reversible chemical marksRNA “writersRNA methylation and neurodegenerative disease mechanismsRNA modification in neurodegenerationRNA processing and regulationRNA-based molecular switches in neurobiologyrole of m6A in neuronal differentiation and function
