Warning on False or True Morels and Button Mushrooms with Potential Toxicity Linked to Hydrazinic Toxins: An Update

Structure of the Mating-Type Genes and Mating Systems of Verpa bohemica and Verpa conica (Ascomycota, Pezizomycotina)

Verpa spp. are potentially important economic fungi within Morchellaceae. However, fundamental research on their mating systems, the key aspects of their life cycle, remains scarce. Fungal sexual reproduction is chiefly governed by mating-type genes, where the configuration of these genes plays a pivotal role in facilitating the reproductive process. For this study, de novo assembly methodologies based on genomic data from Verpa spp. were employed to extract precise information on the mating-type genes, which were then precisely identified in silico and by amplifying their single-ascospore populations using MAT-specific primers. The results suggest that the MAT loci of the three tested strains of V. bohemica encompassed both the MAT1-1-1 and MAT1-2-1 genes, implying homothallism. On the other hand, amongst the three V. conica isolates, only the MAT1-1-1 or MAT1-2-1 genes were present in their MAT loci, suggesting that V. conica is heterothallic. Moreover, bioinformatic analysis reveals that the three tested V. bohemica strains and one V. conica No. 21110 strain include a MAT1-1-10 gene in their MAT loci, while the other two V. conica strains contained MAT1-1-11, exhibiting high amino acid identities with those from corresponding Morchella species. In addition, MEME analysis shows that a total of 17 conserved protein motifs are present among the MAT1-1-10 encoded protein, while the MAT1-1-11 protein contained 10. Finally, the mating type genes were successfully amplified in corresponding single-ascospore populations of V. bohemica and V. conica, further confirming their life-cycle type. This is the first report on the mating-type genes and mating systems of Verpa spp., and the presented results are expected to benefit further exploitation of these potentially important economic fungi.

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.

[Shock and Coma after Ingestion of Morels]

Shock and Coma after Ingestion of Morels Abstract. We present the case report of a previously healthy, 42-year-old woman who suffered from a hypovolemic shock, hypoglycemic coma, NSTEMI and temporary dependency on dialysis following the ingestion of morels. Alas there is little public knowledge about the toxicity of morels and the importance of their appropriate preparation so that intoxications can be prevented.

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.

Outdoor versus indoor cultivation: Effects on the metabolite profile of Agaricus subrufescens strains analyzed by untargeted metabolomics

Agaricus subrufescens has emerged as an important culinary-medicinal mushroom over the last decades. Efforts have been dedicated to upgrade the A. subrufescens productive process via strain selection and cultivation scaling-up. However, little is known on the influence of those variables on the metabolite profiles and nutraceutical properties of this mushroom. In this work, the effects of outdoor versus indoor cultivation on the metabolite profiles of five commercial strains of A. subrufescens were investigated by untargeted metabolomics. UHPLC-MS coupled to multivariate data analysis revealed that the concentration of several metabolites with reported health-related properties as well as related to taste and browning varied significantly between strains and were affected by the cultivation system in a strain-dependent manner. Data suggest that increasing the production scale by means of indoor cultivation may decrease the nutraceutical quality of some A. subrufescens strains while also affecting taste and browning susceptibility to different extents.

Reversible sub-acute motor neuron syndrome after mushroom intoxication masquerading as amyotrophic lateral sclerosis

A 56-year-old man presented with rapidly evolving/sub-acute upper and lower motor neuron syndrome in 2015 with significant weakness in the four limbs and the bulbar region. Amyotrophic lateral sclerosis functional rating scale-revised (ALSFRS-r) was rated 34/48. On electromyography, there was a diffuse and active denervation in the four limbs and the tongue. A diagnosis of definite ALS according to international criteria was made. Six months later the patient stopped worsening. In the following years he progressively recovered. ALSFRS-r score improved to reach 48/48 in 2021. His neurological examination is normal and electromyography shows no denervation. Inquiry revealed that he presented a few months and, again a few days before onset, a mushroom poisoning. He was used to eating false morels either crude or undercooked and developed muscles cramps, nausea and vertigo. The relationships between this reversible sub-acute motor neuron syndrome and mushroom intoxication are discussed in the light of the recently described cluster in the Alps with a high incidence of ALS cases. Epidemiological investigations showed that all patients, but not their spouses, used to eat crude or undercooked false morels. Such a mushroom contains hydrazines, a known neurotoxic agent. We are not aware of another case of ALS reversal in that cluster area. We propose that a potential mushroom poisoning be thoroughly searched for when facing with a patient with sub-acute or rapidly worsening ALS syndrome.

Role of Hydrazine-Related Chemicals in Cancer and Neurodegenerative Disease

Hydrazine-related chemicals (HRCs) with carcinogenic and neurotoxic potential are found in certain mushrooms and plants used for food and in products employed in various industries, including aerospace. Their propensity to induce DNA damage (mostly O⁶-, N⁷- and 8-oxo-guanine lesions) resulting in multiple downstream effects is linked with both cancer and neurological disease. For cycling cells, unrepaired DNA damage leads to mutation and uncontrolled mitosis. By contrast, postmitotic neurons attempt to re-enter the cell cycle but undergo apoptosis or nonapoptotic cell death. Biomarkers of exposure to HRCs can be used to explore whether these substances are risk factors for sporadic amyotrophic laterals sclerosis and other noninherited neurodegenerative diseases, which is the focus of this paper.

An amyotrophic lateral sclerosis hot spot in the French Alps associated with genotoxic fungi

Between 1990 and 2018, 14 cases of amyotrophic lateral sclerosis (ALS) were diagnosed in residents of, and in visitors with second homes to, a mountainous hamlet in the French Alps. Systematic investigation revealed a socio-professional network that connected ALS cases. Genetic risk factors for ALS were excluded. Several known environmental factors were scrutinized and eliminated, notably lead and other chemical contaminants in soil, water or home-grown vegetation used for food, radon and electromagnetic fields. Some lifestyle-related behavioral risk factors were identified: Prior to clinical onset of motor neuron disease, some patients had a high degree of athleticism and smoked tobacco. Recent investigations on site, based on a new hypothesis, showed that all patients had ingested wild mushrooms, notably poisonous False Morels. Half of the ALS cohort reported acute illness following Gyromitra gigas mushroom consumption. This finding supports the hypothesis that genotoxins of fungal origin may induce motor neuron degeneration.

Benzothiazolyl and Benzoxazolyl Hydrazones Function as Zinc Metallochaperones to Reactivate Mutant p53

We identified a set of thiosemicarbazone (TSC) metal ion chelators that reactivate specific zinc-deficient p53 mutants using a mechanism called zinc metallochaperones (ZMCs) that restore zinc binding by shuttling zinc into cells. We defined biophysical and cellular assays necessary for structure-activity relationship studies using this mechanism. We investigated an alternative class of zinc scaffolds that differ from TSCs by substitution of the thiocarbamoyl moiety with benzothiazolyl, benzoxazolyl, and benzimidazolyl hydrazones. Members of this series bound zinc with similar affinity and functioned to reactivate mutant p53 comparable to the TSCs. Acute toxicity and efficacy assays in rodents demonstrated C1 to be significantly less toxic than the TSCs while demonstrating equivalent growth inhibition. We identified C85 as a ZMC with diminished copper binding that functions as a chemotherapy and radiation sensitizer. We conclude that the benzothiazolyl, benzoxazolyl, and benzimidazolyl hydrazones can function as ZMCs to reactivate mutant p53 in vitro and in vivo.