Copper is essential for life as an enzymatic cofactor and antioxidant participant, but in excess, it is toxic to all living organisms, including yeast. Because this toxicity varies by genetic background, we investigated the underlying modifier loci using a panel of four genetically diverse strains—Sake (SA), North American (NA), West African (WA), and Wine/European (WE)—and their segregants. Copper sulfate (CuSO4) susceptibility, quantified by the maximum growth rate (µMax), was strain-dependent, with resistance decreasing in the order SA > WE > WA > NA. Furthermore, cellular growth was inversely correlated with intracellular superoxide levels measured via dihydroethidium staining. By analyzing µMax in 96 segregants from an SA x NA cross exposed to CuSO4, we performed quantitative trait locus (QTL) mapping and prioritized 16 candidate modifiers. Functional validations in a Yhk8 deletant resulted in impaired growth and elevated superoxide levels upon copper exposure. Finally, bioinformatics structural predictions support that Yhk8 is a putative drug/proton antiporter with functional analogy to human SLC47A1, containing a predicted copper-binding site. Together, these findings support Yhk8 as a key genetic modifier of copper response in yeast.
Heavy metal exposure has emerged as a significant environmental contributor to neurodegenerative disease, and a substantial body of mechanistic evidence implicates microglia in the pathological cascades that follow. Lead, cadmium, arsenic, manganese, copper, cobalt, mercury, and zinc disrupt central nervous system homeostasis through multiple cellular targets, but the resident innate immune cells of the brain are well placed to translate these insults into sustained neuroinflammation. Evidence for this critical narrative review was assembled through a purposive search of PubMed, MEDLINE, and Google Scholar for mechanistically informative studies reporting glial endpoints, with reference lists searched by hand and no systematic protocol applied. This review synthesizes current understanding of how individual metals engage microglial signaling networks, with particular attention to oxidative stress, NF-κB activation, NLRP3 inflammasome assembly, MAPK cascades, and suppression of the Nrf2 antioxidant axis. We examine the phenotypic spectrum that extends well beyond the classical M1/M2 dichotomy, including disease-associated microglia, lipid-droplet-accumulating microglia, and interferon-responsive states, and consider how metal-specific signatures map onto these transcriptional programs. Manganese-driven inflammasome assembly, cadmium-induced mitochondrial impairment, lead-mediated disruption of calcium homeostasis, and mercury-evoked autophagic dysfunction are discussed as illustrative examples of mechanistic divergence within a common neuroinflammatory framework. Glial responses to metal mixtures, which better represent real exposure than single-element designs, are considered separately, and the evidence for greater-than-additive effects is appraised. Downstream consequences for astrocyte reactivity, blood–brain barrier integrity, synaptic remodeling, and neuronal viability are placed in the context of Alzheimer’s disease, Parkinson’s disease, and amyotrophic lateral sclerosis. Therapeutic avenues are appraised, including chelation, natural antioxidants, NLRP3 inhibitors, TREM2 modulation, and microglial replacement strategies. Methodological constraints, particularly the overreliance on BV-2 cells and acute high-dose exposure paradigms, are critically considered. The review concludes by identifying priorities for translational research, including longitudinal human cohort studies, single-cell transcriptomic profiling of metal-exposed microglia, and the development of region-specific exposure models that better reflect chronic environmental realities.
Copper is an essential micronutrient involved in several physiological function; however, elevated copper levels are associated with vascular dysfunction. Previous evidence indi-cates that copper overload promotes inflammation in perivascular adipose tissue (PVAT), a key regulator of vascular function. In this context, we investigated whether chronic copper overload modulates the redox profile of mesenteric PVAT and vascular reactivity. Male Wistar rats, 8 weeks old, were divided into two groups: Control (saline, i.p.) and Copper (25.72 µg/kg/day of Cu, i.p., for 30 days). Mesenteric PVAT was collected for analysis of re-active oxygen species (ROS) production, nitric oxide (NO) bioavailability, H₂O₂ levels, total SOD activity, eNOS gene expression, and SOD1, catalase, and NOX4 protein expression. Vascular reactivity to phenylephrine was also evaluated. Serum samples were used for bio-chemical analyses. Chronic copper overload increased the fluorescent signal associated with ROS production in mesenteric PVAT, accompanied by reduced SOD1 protein expres-sion and increased NOX4 protein expression. No significant differences were observed in total SOD activity, eNOS gene expression, or catalase protein levels. NO bioavailability and H₂O₂ levels also remained unchanged. In mesenteric artery rings, copper treatment reduced vascular responsiveness to phenylephrine in the absence of PVAT, while the anticontractile effect of PVAT was maintained after copper exposure. Alterations in redox-related parame-ters were observed in mesenteric PVAT of Wistar rats that received copper, along with a re-duction in phenylephrine-induced contractile responses in mesenteric arteries in the ab-sence of PVAT. However, this reduced vasoconstrictor response was not observed in the presence of PVAT.
Metallothioneins (MTs) are low molecular weight, intracellular, metal sequestering proteins that are unusually rich in cysteine content. Although physiologically comparable to well defined eukaryotic MTs, studies on the roles of prokaryotic MTs are limited. We had previously characterized unannotated prokaryotic MT, namely nmtA in the diazotrophic filamentous cyanobacterium, Anabaena PCC 7120. In the present study, by modulation of the in vivo levels of NmtA, we identified its role in metal homeostasis and detoxification and antioxidant protection in Anabaena 7120. While overexpression of NmtA in Anabaena (AnnmtA+) resulted in enhanced accumulation of Zn2+ and resistance to Cd2+, downregulation of NmtA (AnASnmtA) caused increased Cd2+ sensitivity and lesser accumulation of Zn2+. Probing into metal dependent expression of nmtA, we identified metal sensing motifs in α5 helix of AzuR, the negative regulator of NmtA by site directed mutagenesis. Transcriptome analysis of recombinant Anabaena overexpressing AzuR (AnazuR+) recognized differential gene expression that regulated Zn2+ metabolism. The protective role under oxidative stress of NmtA was affirmed by free radical scavenging ability via oxidative stress-induced Zn2+ mobilization by NmtA and enhanced sensitivity of AnASnmtA to H2O2 stress. The metal binding potential of NmtA prompted us to immobilize NmtA onto citrate functionalized magnetic nanoparticles (CMNP-NmtA) that demonstrated 51
Attention-deficit/hyperactivity disorder (ADHD) is the most common neurodevelopmental disorder in childhood. Its clinical diagnosis primarily relies on behavioral assessments, lacking objective and non-invasive biological indicators. Trace elements are involved in neurotransmitter synthesis, myelin development, and prefrontal cortex function regulation, and their imbalance may be associated with the pathogenesis of ADHD. However, previous studies have mostly focused on single elements, lacking systematic evidence at the omics level. To analyze the differences in 30 skin element levels between children with ADHD and healthy controls, and to explore the associations of elemental imbalances with core symptoms, anxiety, and executive function, thereby providing a basis for non-invasive screening of childhood ADHD. A total of 549 children with ADHD and 963 healthy controls were enrolled. Skin element levels were measured using a non-invasive high-throughput technique. Behavioral assessments were performed using the CONNERS, SNAP‑IV, SCARED, and WEISS scales. Analysis of covariance (ANCOVA) with age as a covariate was used to compare intergroup differences in element levels. Partial correlation analysis was applied to control for age as a confounding factor. The Benjamini‑Hochberg method was used to control the false discovery rate (FDR) for multiple comparison correction, with a significance threshold of q < 0.05. After adjusting for age and FDR correction, 28 elements showed significant differences between the ADHD group and the control group. In the ADHD group, essential/potentially beneficial elements such as Mg, Zn, I, Cr, Li and Ge were decreased, whereas B and harmful elements including Pb, Hg, Cd, As, Al, Be, and Ba were increased. Multiple elements exhibited stable associations with inattention, hyperactivity-impulsivity, anxiety, and risk-taking behavior. Children with ADHD displayed a complex network pattern of synergistic and antagonistic inter-element relationships. Children with ADHD exhibit a characteristic skin trace elementomic imbalance, characterized by decreased beneficial elements and increased harmful elements, which is closely associated with behavioral symptoms. Non-invasive skin elementomics may serve as a reference indicator for population-based risk screening of childhood ADHD and holds promise for population-based screening.
