Role of Hydrazine-Related Chemicals in Cancer and Neurodegenerative Disease

Corrected speciation and gyromitrin content of false morels linked to ALS patients with mostly slow-acetylator phenotypes

A case-control study of sporadic amyotrophic lateral sclerosis (ALS) in a mountainous village in the French Alps discovered an association of cases with a history of eating wild fungi (false morels) collected locally and initially identified and erroneously reported as Gyromitra gigas. Specialist re-examination of dried specimens of the ALS-associated fungi demonstrated they were members of the G. esculenta group, namely G. venenata and G. esculenta, species that have been reported to contain substantially higher concentrations of gyromitrin than present in G. gigas. Gyromitrin is metabolized to monomethylhydrazine, which is responsible not only for the acute oral toxic and neurotoxic properties of false morels but also has genotoxic potential with proposed mechanistic relevance to the etiology of neurodegenerative disease. Most ALS patients had a slow- or intermediate-acetylator phenotype predicted by N-acetyltransferase-2 (NAT2) genotyping, which would increase the risk for neurotoxic and genotoxic effects of gyromitrin metabolites.

Naphthalimide functionalized metal-organic framework for rapid and nanomolar level detection of hydrazine and anti-hypertensive drug nicardipine

The increasing utilization of hydrazine and its derivatives across diverse sectors highlights the pressing need for efficient detection methods to safeguard human health and the environment. Likewise, nicardipine, a widely used medication for heart diseases, necessitates accurate sensing techniques for clinical research and therapeutic monitoring. Here, we propose a novel approach using a naphthalimide-functionalized Zr-MOF as a fluorometric probe capable of detecting both hydrazine and nicardipine in aqueous medium. Our designed probe exhibited a significant 31-fold increase in fluorescence intensity upon interaction with hydrazine. At the same time, nicardipine induced 86% fluorescence quenching with an exceptionally rapid response time (100 s for hydrazine and 5 s for nicardipine). The designed probe has the ability to detect both analytes at nanomolar concentrations (LOD for hydrazine is 1.11 nM while that for nicardipine is 9.6 nM). Investigation across various wastewater samples and pH conditions further validated its practical utility. The mechanism behind fluorometric sensing of nicardipine was thoroughly investigated using modern instrumentation. Our study presents a versatile and effective approach for detecting hydrazine and nicardipine, addressing crucial needs in both industrial and biomedical contexts.

Near-Infrared Catalytic Chemiluminescence System based on Zinc Gallate Nanoprobe for Hydrazine Sensing

To the deep tissue penetration and ultra-low background, developing near-infrared (NIR) chemiluminescence probes for human health and environmental safety has attracted more and more attention, but it remains a huge challenge. Herein, a novel NIR chemiluminescence (CL) system was rationally designed and developed, utilizing Cr3+-activated ZnGa2O4 (ZGC) nanoparticles as a catalytic luminophore via hypochlorite (NaClO) activation for poisonous target (hydrazine, N2H4) detection. With superior optical performance and unique catalytic structure of ZGC nanoparticles, the fabricated ZGC-NaClO-N2H4 CL system successfully demonstrated excellent NIR emission centered at 700 nm, fast response, and high sensibility (limit of detection down to 0.0126 μM). Further experimental studies and theoretical calculations found the cooperative catalytic chemiluminescence resonance energy transfer mechanism in the ZGC-NaClO-N2H4 system. Remarkably, the ZGC-based NIR CL system was further employed for N2H4 detection in a complicated matrix involving bioimaging and real water samples, thereby opening a new way as a highly reliable and accurate tool in biomedical and environmental monitoring applications.

Avocational exposure associations with ALS risk, survival, and phenotype: A Michigan-based case-control study

INTRODUCTION

Environmental exposures strongly influence ALS risk and identification is needed to reduce ALS burden. Participation in hobbies and exercise may alter ALS risk and phenotype, warranting an assessment to understand their contribution to the ALS exposome.

METHODS

Participants with ALS and healthy controls were recruited from University of Michigan and self-completed a survey to ascertain hobbies, exercise, and avocational exposures. Exposure variables were associated with ALS risk, survival, onset segment, and onset age.

RESULTS

ALS (n = 400) and control (n = 287) participants self-reported avocational activities. Cases were slightly older (median age 63.0 vs. 61.1 years, p = 0.019) and had a lower educational attainment (p < 0.001) compared to controls; otherwise, demographics were well balanced. Risks associating with ALS after multiple comparison correction included golfing (odds ratio (OR) 3.48, padjusted = 0.004), recreational dancing (OR 2.00, padjusted = 0.040), performing gardening or yard work (OR 1.71, padjusted = 0.040) five years prior to ALS and personal (OR 1.76, padjusted = 0.047) or family (OR 2.21, padjusted = 0.040) participation in woodworking, and personal participation in hunting and shooting (OR 1.89, padjusted = 0.040). No exposures associated with ALS survival and onset. Those reporting swimming (3.86 years, padjusted = 0.016) and weightlifting (3.83 years, padjusted = 0.020) exercise 5 years prior to ALS onset had an earlier onset age.

DISCUSSION

The identified exposures in this study may represent important modifiable ALS factors that influence ALS phenotype. Thus, exposures related to hobbies and exercise should be captured in studies examining the ALS exposome.

Novel biosynthesis of gold nanoparticles for multifunctional applications: Electrochemical detection of hydrazine and treatment of gastric cancer

In this work, an environmentally friendly strategy was used to synthesize gold nanoparticles (Au NPs) using Olea europaea (olive) fruit. Transmission electron microscopy (TEM), UV-Vis spectroscopy, X-ray diffraction (XRD) and energy-dispersive X-ray (EDX) were used to characterize the physicochemical properties of the synthesized NPs. An Au NPs modified glassy carbon electrode was used to investigate the direct electrochemical oxidation of hydrazine. The suggested hydrazine sensor has good performance, such as a wide linear range (2.5-275 μM), low limit of detection (0.09 μM), notable selectivity and excellent reproducibility (RSD = 2.2%). The in-vitro cytotoxicity of three human cancer cell lines (KATOIII, NCI-N87, and SNU-16) was also explored with various concentrations of Au NPs prepared from olive fruit extract. Bio-synthesized Au NPs were found to have cytotoxic properties against gastric cancer in humans based on MTT assay protocol. The obtained results show that green synthesized Au NPs can be successfully employed in electrochemical sensing and cancer treatment applications.

Environmental neurology: Concepts and short history of an interdisciplinary approach to etiology, treatment and prevention

Environmental Neurology (EN), a sub-discipline of Neurology and Neurological Sciences, favors an interdisciplinary collaboration allowing a holistic approach to understanding the impact of environmental factors on the nervous system and their relationship with neurological diseases. Several examples of diseases and conditions show the large scope of subjects addressed by EN. The EN sub-discipline focuses on both individual and population issues thus joining patient care and public health, respectively. Neuropathogenesis is addressed by several major questions: How do the environment and nervous system interact? Which exogenous factors can trigger neurological disease? When, where and how do they act? What are the therapeutic implications, and how can these disorders be controlled or prevented. To answer such questions, we address the incentive for, philosophy of and methods developed by EN, which seeks to safeguard Brain Health and, thus, the quality of life.

Early-onset, conjugal, twin-discordant, and clusters of sporadic ALS: Pathway to discovery of etiology via lifetime exposome research

The identity and role of environmental factors in the etiology of sporadic amyotrophic lateral sclerosis (sALS) is poorly understood outside of three former high-incidence foci of Western Pacific ALS and a hotspot of sALS in the French Alps. In both instances, there is a strong association with exposure to DNA-damaging (genotoxic) chemicals years or decades prior to clinical onset of motor neuron disease. In light of this recent understanding, we discuss published geographic clusters of ALS, conjugal cases, single-affected twins, and young-onset cases in relation to their demographic, geographic and environmental associations but also whether, in theory, there was the possibility of exposure to genotoxic chemicals of natural or synthetic origin. Special opportunities to test for such exposures in sALS exist in southeast France, northwest Italy, Finland, the U.S. East North Central States, and in the U.S. Air Force and Space Force. Given the degree and timing of exposure to an environmental trigger of ALS may be related to the age at which the disease is expressed, research should focus on the lifetime exposome (from conception to clinical onset) of young sALS cases. Multidisciplinary research of this type may lead to the identification of ALS causation, mechanism, and primary prevention, as well as to early detection of impending ALS and pre-clinical treatment to slow development of this fatal neurological disease.

Not all bad: Gyromitrin has a limited distribution in the false morels as determined by a new ultra high-performance liquid chromatography method

Gyromitrin (acetaldehyde N-methyl-N-formylhydrazone) and its homologs are deadly mycotoxins produced most infamously by the lorchel (also known as false morel) Gyromitra esculenta, which is paradoxically consumed as a delicacy in some parts of the world. There is much speculation about the presence of gyromitrin in other species of the lorchel family (Discinaceae), but no studies have broadly assessed its distribution. Given the history of poisonings associated with the consumption of G. esculenta and G. ambigua, we hypothesized that gyromitrin evolved in the last common ancestor of these taxa and would be present in their descendants with adaptive loss of function in the nested truffle clade, Hydnotrya. To test this hypothesis, we developed a sensitive analytical derivatization method for the detection of gyromitrin using 2,4-dinitrobenzaldehyde as the derivatization reagent. In total, we analyzed 66 specimens for the presence of gyromitrin over 105 tests. Moreover, we sequenced the nuc rDNA internal transcribed spacer region ITS1-5.8S-ITS2 (ITS barcode) and nuc 28S rDNA to assist in species identification and to infer a supporting phylogenetic tree. We detected gyromitrin in all tested specimens from the G. esculenta group as well as G. leucoxantha. This distribution is consistent with a model of rapid evolution coupled with horizontal transfer, which is typical for secondary metabolites. We clarified that gyromitrin production in Discinaceae is both discontinuous and more limited than previously thought. Further research is required to elucidate the gyromitrin biosynthesis gene cluster and its evolutionary history in lorchels.

Hydrazine High-Performance Oxidation and Sensing Using a Copper Oxide Nanosheet Electrocatalyst Prepared via a Foam-Surfactant Dual Template

This work demonstrates hydrazine electro-oxidation and sensing using an ultrathin copper oxide nanosheet (CuO-NS) architecture prepared via a versatile foam-surfactant dual template (FSDT) approach. CuO-NS was synthesised by chemical deposition of the hexagonal surfactant Brij^®58 liquid crystal template containing dissolved copper ions using hydrogen foam that was concurrently generated by a sodium borohydride reducing agent. The physical characterisations of the CuO-NS showed the formation of a two-dimensional (2D) ultrathin nanosheet architecture of crystalline CuO with a specific surface area of ~39 m²/g. The electrochemical CuO-NS oxidation and sensing performance for hydrazine oxidation revealed that the CuO nanosheets had a superior oxidation performance compared with bare-CuO, and the reported state-of-the-art catalysts had a high hydrazine sensitivity of 1.47 mA/cm² mM, a low detection limit of 15 μM (S/N = 3), and a linear concentration range of up to 45 mM. Moreover, CuO-NS shows considerable potential for the practical use of hydrazine detection in tap and bottled water samples with a good recovery achieved. Furthermore, the foam-surfactant dual template (FSDT) one-pot synthesis approach could be used to produce a wide range of nanomaterials with various compositions and nanoarchitectures at ambient conditions for boosting the electrochemical catalytic reactions.

Space tourism needs a bioethical reboot

Space tourism includes a medical ‘module’, which studies physiopsychic variables of these ‘tourists’. Therefore, before sub-orbiting the Earth, this type of space travel should orbit the ethical safeguards of research. Such a premise has, as far as Sub-orbital Space Tourism is concerned, three domains: subject bioethics, social bioethics, and eco-bioethics.

Nodding syndrome: A key role for sources of nutrition?

Nodding Syndrome (NS) has occurred among severely food-stressed communities in northern Uganda and several other East African populations that, with their forced physical displacement, have resorted to nutritional support from available wild plants and fungi, some of which have neurotoxic potential. Among the latter is an agaric mushroom with an unknown content of hydrazine-generating agaritine, namely Agaricus bingensis, the unusually wide consumption of which may relate to the low serum levels of vitamin B6 in Ugandan NS subjects relative to controls. Hydrazine-related compounds induce patterns of DNA damage that promote neuropathological changes (tauopathy) reminiscent of those associated with established NS. While the cause of this childhood brain disease is unknown, we encourage increased attention to the role of malnutrition and B6 hypovitaminosis in the etiology of this devastating brain disease.

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Idiopathic epileptic encephalopathy with tauopathy (Nodding syndrome) impacts East African children

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Associated factors include nematode infection, food insecurity, and food use of wild plants and fungi

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Food use of hydrazinic fungi induces B6 hypovitaminosis, which may be marked in Nodding syndrome

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Vitamin B6 deficiency promotes tau phosphorylation in mouse models of human tauopathy

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Hydrazine generates carbon free radicals associated with DNA-damage and neurodegenerative disease

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Increased research attention to nutritional practices associated with Nodding syndrome is merited.

1,2-Dehydropyrrolizidine Alkaloids: Their Potential as a Dietary Cause of Sporadic Motor Neuron Diseases

Sporadic motor neuron diseases (MNDs), such as amyotrophic lateral sclerosis (ALS), can be caused by spontaneous genetic mutations. However, many sporadic cases of ALS and other debilitating neurodegenerative diseases (NDDs) are believed to be caused by environmental factors, subject to considerable debate and requiring intensive research. A common pathology associated with MND development involves progressive mitochondrial dysfunction and oxidative stress in motor neurons and glial cells of the central nervous system (CNS), leading to apoptosis. Consequent degeneration of skeletal and respiratory muscle cells can lead to death from respiratory failure. A significant number of MND cases present with cancers and liver and lung pathology. This Perspective explores the possibility that MNDs could be caused by intermittent, low-level dietary exposure to 1,2-dehydropyrrolizidine alkaloids (1,2-dehydroPAs) that are increasingly recognized as contaminants of many foods consumed throughout the world. Nontoxic, per se, 1,2-dehydroPAs are metabolized, by particular cytochrome P450 (CYP450) isoforms, to 6,7-dihydropyrrolizines that react with nucleophilic groups (-NH, -SH, -OH) on DNA, proteins, and other vital biochemicals, such as glutathione. Many factors, including aging, gender, smoking, and alcohol consumption, influence CYP450 isoform activity in a range of tissues, including glial cells and neurons of the CNS. Activation of 1,2-dehydroPAs in CNS cells can be expected to cause gene mutations and oxidative stress, potentially leading to the development of MNDs and other NDDs. While relatively high dietary exposure to 1,2-dehydroPAs causes hepatic sinusoidal obstruction syndrome, pulmonary venoocclusive disease, neurotoxicity, and diverse cancers, this Perspective suggests that, at current intermittent, low levels of dietary exposure, neurotoxicity could become the primary pathology that develops over time in susceptible individuals, along with a tendency for some of them to also display liver and lung pathology and diverse cancers co-occurring with some MND/NDD cases. Targeted research is recommended to investigate this proposal.

Genotoxic Damage During Brain Development Presages Prototypical Neurodegenerative Disease

Western Pacific Amyotrophic Lateral Sclerosis and Parkinsonism-Dementia Complex (ALS/PDC) is a disappearing prototypical neurodegenerative disorder (tau-dominated polyproteinopathy) linked with prior exposure to phytogenotoxins in cycad seed used for medicine and/or food. The principal cycad genotoxin, methylazoxymethanol (MAM), forms reactive carbon-centered ions that alkylate nucleic acids in fetal rodent brain and, depending on the timing of systemic administration, induces persistent developmental abnormalities of the cortex, hippocampus, cerebellum, and retina. Whereas administration of MAM prenatally or postnatally can produce animal models of epilepsy, schizophrenia or ataxia, administration to adult animals produces little effect on brain structure or function. The neurotoxic effects of MAM administered to rats during cortical brain development (specifically, gestation day 17) are used to model the histological, neurophysiological and behavioral deficits of human schizophrenia, a condition that may precede or follow clinical onset of motor neuron disease in subjects with sporadic ALS and ALS/PDC. While studies of migrants to and from communities impacted by ALS/PDC indicate the degenerative brain disorder may be acquired in juvenile and adult life, a proportion of indigenous cases shows neurodevelopmental aberrations in the cerebellum and retina consistent with MAM exposure in utero. MAM induces specific patterns of DNA damage and repair that associate with increased tau expression in primary rat neuronal cultures and with brain transcriptional changes that parallel those associated with human ALS and Alzheimer’s disease. We examine MAM in relation to neurodevelopment, epigenetic modification, DNA damage/replicative stress, genomic instability, somatic mutation, cell-cycle reentry and cellular senescence. Since the majority of neurodegenerative disease lacks a solely inherited genetic basis, research is needed to explore the hypothesis that early-life exposure to genotoxic agents may trigger or promote molecular events that culminate in neurodegeneration.

Parkinsonism and motor neuron disorders: Lessons from Western Pacific ALS/PDC

Recognized worldwide as an unusual "overlap" syndrome, Parkinsonism and motor neuron disease, with or without dementia, is best exemplified by the former high-incidence clusters of Amyotrophic Lateral Sclerosis and Parkinsonism-Dementia Complex (ALS/PDC) in Guam, USA, in the Kii Peninsula of Honshu Island, Japan, and in Papua, Indonesia, on the western side of New Guinea. Western Pacific ALS/PDC is a disappearing neurodegenerative disorder with multiple and sometime overlapping phenotypes (ALS, atypical parkinsonism, dementia) that appear to constitute a single disease of environmental origin, in particular from exposure to genotoxins/neurotoxins in seed of cycad plants (Cycas spp.) formerly used as a traditional source of food (Guam) and/or medicine (Guam, Kii-Japan, Papua-Indonesia). Seed compounds include the principal cycad toxin cycasin, its active metabolite methylazoxymethanol (MAM) and a non-protein amino acid β-N-methylamino-L-alanine (L-BMAA); each reproduces components of ALS/PDC neuropathology when individually administered to laboratory species in single doses perinatally (MAM, L-BMAA) or repeatedly for prolonged periods to young adult animals (L-BMAA). Human exposure to MAM, a potent DNA-alkylating mutagen, also has potential relevance to the high incidence of diverse mutations found among Guamanians with/without ALS/PDC. In sum, seven decades of intensive study of ALS/PDC has revealed field and laboratory approaches leading to discovery of disease etiology that are now being applied to sporadic neurodegenerative disorders such as ALS beyond the Western Pacific region. This article is part of the Special Issue "Parkinsonism across the spectrum of movement disorders and beyond" edited by Joseph Jankovic, Daniel D. Truong and Matteo Bologna.

Direct and Indirect Neurotoxic Potential of Metal/Metalloids in Plants and Fungi Used for Food, Dietary Supplements, and Herbal Medicine

Plants and mushrooms bioconcentrate metals/metalloids from soil and water such that high levels of potentially neurotoxic elements can occur in cultivated and wild species used for food. While the health effects of excessive exposure to metals/metalloids with neurotoxic potential are well established, overt neurological disease from prolonged ingestion of contaminated botanicals has not been recognized. However, the presence of metal elements may affect levels of botanical neurotoxins in certain plants and mushrooms that are established causes of acute and chronic neurological disease.