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1.
Sci Rep ; 14(1): 8017, 2024 04 05.
Artículo en Inglés | MEDLINE | ID: mdl-38580836

RESUMEN

Cyanobacteria produce neurotoxic non-protein amino acids (NPAAs) that accumulate in ecosystems and food webs. American lobsters (Homarus americanus H. Milne-Edwards) are one of the most valuable seafood industries in Canada with exports valued at > $2 billion. Two previous studies have assessed the occurrence of ß-N-methylamino-L-alanine (BMAA) in a small number of lobster tissues but a complete study has not previously been undertaken. We measured NPAAs in eyeballs, brain, legs, claws, tails, and eggs of 4 lobsters per year for the 2021 and 2022 harvests. Our study included 4 male and 4 female lobsters. We detected BMAA and its isomers, N-(2-aminoethyl)glycine (AEG), 2,4-diaminobutyric acid (DAB) and ß-aminomethyl-L-alanine (BAMA) by a fully validated reverse phase chromatography-tandem mass spectrometry method. We quantified BMAA, DAB, AEG and BAMA in all of the lobster tissues. Our quantification data varied by individual lobster, sex and collection year. Significantly more BMAA was quantified in lobsters harvested in 2021 than 2022. Interestingly, more BAMA was quantified in lobsters harvested in 2022 than 2021. Monitoring of lobster harvests for cyanobacterial neurotoxins when harmful algal bloom events occur could mitigate risks to human health.


Asunto(s)
Aminoácidos Diaminos , Decápodos , Síndromes de Neurotoxicidad , Animales , Masculino , Femenino , Humanos , Nephropidae/metabolismo , Ecosistema , Neurotoxinas/toxicidad , Aminoácidos Diaminos/metabolismo , Alimentos Marinos/análisis , Decápodos/metabolismo , beta-Alanina
2.
J Drugs Dermatol ; 23(3): 173-186, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38443133

RESUMEN

BACKGROUND: Botulinum neurotoxin (BoNT) exhibits inhibitory effects on the neuromuscular junction, and its use is well established in cosmetic dermatology. Our review aims to analyze the evidence for its use in the treatment of various dermatological, neurological, gastroenterological, ophthalmological, otorhinolaryngological, dental, urological, gynecological, and cardiovascular disorders. METHODS: A systematic review of the literature was performed for studies published between 2012 and 2022 that discussed the therapeutic use of BoNT in human participants. A total of 58 studies were selected for inclusion in this review.  Results: We discovered a large range of therapeutic applications of BoNT toxin beyond aesthetic and US Food and Drug Administration (FDA)-approved non-aesthetic uses.  Conclusions: BoNT is a powerful neurotoxin that has varied FDA-approved indications and has been studied in a wide range of therapeutic applications. Further investigation through higher power studies is needed to assess the potential of BoNT and expand its versatility across other medical specialties.  J Drugs Dermatol. 2024;23(3):173-186. doi:10.36849/JDD.7243e.


Asunto(s)
Toxinas Botulínicas , Enfermedades Cardiovasculares , Oftalmología , Humanos , Toxinas Botulínicas/uso terapéutico , Estética , Neurotoxinas/uso terapéutico , Estados Unidos
3.
Sci Adv ; 10(11): eadk3870, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38478603

RESUMEN

The ability of an animal to effectively capture prey and defend against predators is pivotal for survival. Venom is often a mixture of many components including toxin proteins that shape predator-prey interactions. Here, we used the sea anemone Nematostella vectensis to test the impact of toxin genotypes on predator-prey interactions. We developed a genetic manipulation technique to demonstrate that both transgenically deficient and a native Nematostella strain lacking a major neurotoxin (Nv1) have a reduced ability to defend themselves against grass shrimp, a native predator. In addition, secreted Nv1 can act indirectly in defense by attracting mummichog fish, which prey on grass shrimp. Here, we provide evidence at the molecular level of an animal-specific tritrophic interaction between a prey, its antagonist, and a predator. Last, this study reveals an evolutionary trade-off, as the reduction of Nv1 levels allows for faster growth and increased reproductive rates.


Asunto(s)
Anémonas de Mar , Ponzoñas , Animales , Reproducción , Evolución Biológica , Neurotoxinas/genética , Anémonas de Mar/genética , Conducta Predatoria/fisiología
4.
Harmful Algae ; 133: 102602, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38485439

RESUMEN

Pseudo-nitzschia is a cosmopolitan phytoplankton genus of which some species can form blooms and produce the neurotoxin domoic acid (DA). Identification of Pseudo-nitzschia is generally based on field material or strains followed by morphological and/or molecular characterization. However, this process is time-consuming and laborious, and can not obtain a relatively complete and reliable profile of the Pseudo-nitzschia community, because species with low abundance in the field or potentially unavailable for culturing may easily be overlooked. In the present study, specific ITS primer sets were designed and evaluated using in silico matching. The primer set ITS-84F/456R involving the complete ITS1 region was found optimal. Based on matching with a Pseudo-nitzschia ITS1 reference sequence database carefully-calibrated in this study, a metabarcoding approach using annotated amplicon sequence variants (ASV) was applied in the Taiwan Strait of the East China Sea during two cruises in the spring and summer of 2019. In total, 48 Pseudo-nitzschia species/phylotypes including 36 known and 12 novel were uncovered, and verified by haplotype networks, ITS2 secondary structure comparisons and divergence analyses. Correlation analyses revealed that temperature was a key factor affecting the seasonal variation of the Pseudo-nitzschia community. This study provides an overview of the Pseudo-nitzschia community in the Taiwan Strait, with new insights into the diversity. The developed metabarcoding approach may be used elsewhere as a standard reference for accurate annotation of Pseudo-nitzschia.


Asunto(s)
Diatomeas , Taiwán , Diatomeas/química , Fitoplancton , Neurotoxinas , Estaciones del Año
5.
Int J Mol Sci ; 25(6)2024 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-38542133

RESUMEN

The present investigation was designed based on the evidence that, in neurodegenerative disorders, such as Alzheimer's dementia (AD) and Parkinson's disease (PD), damage to the locus coeruleus (LC) arising norepinephrine (NE) axons (LC-NE) is documented and hypothesized to foster the onset and progression of neurodegeneration within target regions. Specifically, the present experiments were designed to assess whether selective damage to LC-NE axons may alter key proteins involved in neurodegeneration within specific limbic regions, such as the hippocampus and piriform cortex, compared with the dorsal striatum. To achieve this, a loss of LC-NE axons was induced by the neurotoxin N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP4) in C57 Black mice, as assessed by a loss of NE and dopamine-beta-hydroxylase within target regions. In these experimental conditions, the amount of alpha-synuclein (alpha-syn) protein levels were increased along with alpha-syn expressing neurons within the hippocampus and piriform cortex. Similar findings were obtained concerning phospho-Tau immunoblotting. In contrast, a decrease in inducible HSP70-expressing neurons and a loss of sequestosome (p62)-expressing cells, along with a loss of these proteins at immunoblotting, were reported. The present data provide further evidence to understand why a loss of LC-NE axons may foster limbic neurodegeneration in AD and limbic engagement during PD.


Asunto(s)
Enfermedad de Alzheimer , Enfermedad de Parkinson , Ratones , Animales , Locus Coeruleus/metabolismo , Norepinefrina/metabolismo , Neuronas/metabolismo , Neurotoxinas/farmacología , Axones/metabolismo , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/metabolismo , Enfermedad de Parkinson/metabolismo
6.
Neurotox Res ; 42(1): 11, 2024 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-38319410

RESUMEN

Parkinson's disease (PD) is the second most common neurodegenerative disease in the world, the first being Alzheimer's disease. Patients with PD have a loss of dopaminergic neurons in the substantia nigra of the basal ganglia, which controls voluntary movements, causing a motor impairment as a result of dopaminergic signaling impairment. Studies have shown that mutations in several genes, such as SNCA, PARK2, PINK1, DJ-1, ATP13A2, and LRRK2, and the exposure to neurotoxic agents can potentially increase the chances of PD development. The nematode Caenorhabditis elegans (C. elegans) plays an important role in studying the risk factors, such as genetic factors, aging, exposure to chemicals, disease progression, and drug treatments for PD. C. elegans has a conserved neurotransmission system during evolution; it produces dopamine, through the eight dopaminergic neurons; it can be used to study the effect of neurotoxins and also has strains that express human α-synuclein. Furthermore, the human PD-related genes, LRK-1, PINK-1, PDR-1, DJR-1.1, and CATP-6, are present and functional in this model. Therefore, this review focuses on highlighting and discussing the use of C. elegans an in vivo model in PD-related studies. Here, we identified that nematodes exposed to the neurotoxins, such as 6-OHDA, MPTP, paraquat, and rotenone, had a progressive loss of dopaminergic neurons, dopamine deficits, and decreased survival rate. Several studies have reported that expression of human LRRK2 (G2019S) caused neurodegeneration and pink-1, pdr-1, and djr-1.1 deletion caused several effects PD-related in C. elegans, including mitochondrial dysfunctions. Of note, the deletion of catp-6 in nematodes caused behavioral dysfunction, mitochondrial damage, and reduced survival. In addition, nematodes expressing α-synuclein had neurodegeneration and dopamine-dependent deficits. Therefore, C. elegans can be considered an accurate animal model of PD that can be used to elucidate to assess the underlying mechanisms implicated in PD to find novel therapeutic targets.


Asunto(s)
Proteínas de Caenorhabditis elegans , Enfermedades Neurodegenerativas , Enfermedad de Parkinson , Animales , Humanos , Enfermedad de Parkinson/genética , alfa-Sinucleína/genética , Caenorhabditis elegans , Neurotoxinas , Dopamina , Adenosina Trifosfatasas , Proteínas de Caenorhabditis elegans/genética
7.
Toxins (Basel) ; 16(2)2024 02 02.
Artículo en Inglés | MEDLINE | ID: mdl-38393153

RESUMEN

Cnidarians (corals, sea anemones, and jellyfish) produce toxins that play central roles in key ecological processes, including predation, defense, and competition, being the oldest extant venomous animal lineage. Cnidaria small cysteine-rich proteins (SCRiPs) were the first family of neurotoxins detected in stony corals, one of the ocean's most crucial foundation species. Yet, their molecular evolution remains poorly understood. Moreover, the lack of a clear classification system has hindered the establishment of an accurate and phylogenetically informed nomenclature. In this study, we extensively surveyed 117 genomes and 103 transcriptomes of cnidarians to identify orthologous SCRiP gene sequences. We annotated a total of 168 novel putative SCRiPs from over 36 species of stony corals and 12 species of sea anemones. Phylogenetic reconstruction identified four distinct SCRiP subfamilies, according to strict discrimination criteria based on well-supported monophyly with a high percentage of nucleotide and amino acids' identity. Although there is a high prevalence of purifying selection for most SCRiP subfamilies, with few positively selected sites detected, a subset of Acroporidae sequences is influenced by diversifying positive selection, suggesting potential neofunctionalizations related to the fine-tuning of toxin potency. We propose a new nomenclature classification system relying on the phylogenetic distribution and evolution of SCRiPs across Anthozoa, which will further assist future proteomic and functional research efforts.


Asunto(s)
Antozoos , Cnidarios , Anémonas de Mar , Animales , Antozoos/genética , Anémonas de Mar/genética , Cnidarios/genética , Neurotoxinas/genética , Cisteína/genética , Filogenia , Proteómica
8.
Toxins (Basel) ; 16(2)2024 02 10.
Artículo en Inglés | MEDLINE | ID: mdl-38393175

RESUMEN

Since its regulatory approval over a half-century ago, botulinum toxin has evolved from one of the most potent neurotoxins known to becoming routinely adopted in clinical practice. Botulinum toxin, a highly potent neurotoxin produced by Clostridium botulinum, can cause botulism illness, characterized by widespread muscle weakness due to inhibition of acetylcholine transmission at neuromuscular junctions. The observation of botulinum toxin's anticholinergic properties led to the investigation of its potential benefits for conditions with an underlying etiology of cholinergic transmission, including autonomic nervous system dysfunction. These conditions range from disorders of the integument to gastrointestinal and urinary systems. Several formulations of botulinum toxin have been developed and tested over time, significantly increasing the availability of this treatment for appropriate clinical use. Despite the accelerated and expanded use of botulinum toxin, there lacks an updated comprehensive review on its therapeutic use, particularly to treat autonomic dysfunction. This narrative review provides an overview of the effect of botulinum toxin in the treatment of autonomic dysfunction and summarizes the different formulations and dosages most widely studied, while highlighting reported outcomes and the occurrence of any adverse events.


Asunto(s)
Enfermedades del Sistema Nervioso Autónomo , Toxinas Botulínicas , Botulismo , Clostridium botulinum , Humanos , Toxinas Botulínicas/efectos adversos , Botulismo/terapia , Neurotoxinas , Enfermedades del Sistema Nervioso Autónomo/tratamiento farmacológico
9.
Protein Expr Purif ; 218: 106447, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38369031

RESUMEN

Diaminopropionate ammonia-lyase transforms D and L isomers of 2,3-diaminopropionate to pyruvate and ammonia. It catalyzes D- and l-serine less effectively. L-2,3-diaminopropionate is a precursor in the biosynthesis of oxalyl diaminopropionate as a neurotoxin in certain legume species. In this work, we cyclized the diaminopropionate ammonia-lyase from Salmonella typhimurium in vitro using the redox-responsive split intein, and identified that backbone cyclization afforded the enzyme with the improved activity, thermal stability and resistance to the exopeptidase proteolysis, different from effects of the incorporated sequence recognized by tobacco vein mottling virus protease at C-terminus. Using analyses of three fluorescent dyes including 8-anilino-1-naphthalenesulfonic acid, N-phenyl-1-naphthylamine, and thioflavin T, the same amounts of the cyclic protein displayed less fluorescence than those of the linear protein upon the heat treatment. The cyclic enzyme displayed the enhanced activity in Escherichia coli cells using the designed novel reporter. In this system, d-serine was added to the culture and transported into the cytoplasm. It was transformed by pre-overexpression of the diaminopropionate ammonia-lyase, and untransformed d-serine was oxidized by the coproduced human d-amino acid oxidase to generate hydrogen peroxide. This oxidant is monitored by the HyPer indicator. The current results presented that the cyclized enzyme could be applied as a better candidate to block the neurotoxin biosynthesis in certain plant species.


Asunto(s)
Amoníaco-Liasas , Neurotoxinas , Salmonella typhimurium , Humanos , Ciclización , Escherichia coli/genética , Serina
10.
mBio ; 15(3): e0310623, 2024 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-38347673

RESUMEN

Botulinum neurotoxins (BoNTs) are a class of toxins produced by Clostridium botulinum (C. botulinum) and other species of Clostridia. BoNT/X is a putative novel botulinum neurotoxin identified through genome sequencing and capable of SNARE cleavage, but its neurotoxic potential in humans and vertebrates remained unclear. The C. botulinum strain producing BoNT/X, Strain 111, encodes both a plasmid-borne bont/b2 as well as the chromosomal putative bont/x. This study utilized C. botulinum Strain 111 from Japan as well as recombinantly produced full-length BoNT/X to more fully analyze this putative pathogenic toxin. We confirmed production of full-length, catalytically active native BoNT/X by C. botulinum Strain 111, produced as a disulfide-bonded dichain polypeptide similar to other BoNTs. Both the purified native and the recombinant BoNT/X had high enzymatic activity in vitro but displayed very low potency in human-induced pluripotent stem cell-derived neuronal cells and in mice. Intraperitoneal injection of up to 50 µg of native BoNT/X in mice did not result in botulism; however, mild local paralysis was observed after injection of 2 µg into the gastrocnemius muscle. We further demonstrate that the lack of toxicity by BoNT/X is due to inefficient neuronal cell association and entry, which can be rescued by replacing the receptor binding domain of BoNT/X with that of BoNT/A. These data demonstrate that BoNT/X is not a potent vertebrate neurotoxin like the classical seven serotypes of BoNTs. IMPORTANCE: The family of botulinum neurotoxins comprises the most potent toxins known to humankind. New members of this family of protein toxins as well as more distantly related homologs are being identified. The discovery of BoNT/X via bioinformatic screen in 2017 as a putative new BoNT serotype raised concern about its potential as a pathogenic agent with no available countermeasures. This study for the first time assessed both recombinantly produced and native purified BoNT/X for its vertebrate neurotoxicity.


Asunto(s)
Botulismo , Clostridium botulinum , Humanos , Animales , Ratones , Neurotoxinas/química , Neurotoxinas/genética , Neurotoxinas/metabolismo , Clostridium botulinum/genética , Plásmidos , Neuronas/metabolismo
11.
Sci Total Environ ; 922: 171255, 2024 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-38417517

RESUMEN

The neurotoxin ß-N-methylamino-L-alanine (BMAA) has been deemed as a risk factor for some neurodegenerative diseases such as amyotrophic lateral sclerosis/parkinsonism dementia complex (ALS/PDC). This possible link has been proved in some primate models and cell cultures with the appearance that BMAA exposure can cause excitotoxicity, formation of protein aggregates, and/or oxidative stress. The neurotoxin BMAA extensively exists in the environment and can be transferred through the food web to human beings. In this review, the occurrence, toxicological mechanisms, and characteristics of BMAA were comprehensively summarized, and proteins and peptides were speculated as its possible binding substances in biological matrices. It is difficult to compare the published data from previous studies due to the inconsistent analytical methods and components of BMAA. The binding characteristics of BMAA should be focused on to improve our understanding of its health risk to human health in the future.


Asunto(s)
Aminoácidos Diaminos , Neurotoxinas , Animales , Humanos , Neurotoxinas/química , Aminoácidos Diaminos/toxicidad , Aminoácidos Diaminos/química , Toxinas de Cianobacterias , Estrés Oxidativo
12.
Environ Sci Pollut Res Int ; 31(15): 22885-22899, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38418784

RESUMEN

The aim of this study is twofold: i) to determine innovative yet sensitive endpoints for sulfoxaflor and ii) to develop best practices for innovative teaching in ecotoxicology. To this end, a group of 52 MSc students participated in an environmental hackathon, during which they did creative toxicity testing on 5 freshwater invertebrate species: Daphnia magna, Chironomus riparius, Asellus aquaticus, Lymnaea stagnalis, and Anisus vortex. Involving the students in an active learning environment stimulated increased creativity and productivity. In total, 28 endpoints were investigated, including standard endpoints (e.g., mortality) as well as biomechanistic and energy-related endpoints. Despite high variances in the results, likely linked to the limited lab experience of the students and interpersonal differences, a promising set of endpoints was selected for further investigation. A more targeted follow-up experiment focused on the most promising organism and set of endpoints: biomechanistic endpoints of C. riparius larvae. Larvae were exposed to a range of sulfoxaflor concentrations (0.90-67.2 µg/L) for 21 days. Video tracking showed that undulation and swimming were significantly reduced at 11.1 µg sulfoxaflor/L after 9 days of exposure, and an EC50 = 10.6 µg/L for mean velocities of the larvae in the water phase was found. Biomechanistic endpoints proved much more sensitive than mortality, for which an LC50 value of 116 µg/L was found on Day 9. Our results show that performing a hackathon with students has excellent potential to find sensitive endpoints that can subsequently be verified using more targeted and professional follow-up experiments. Furthermore, utilising hackathon events in teaching can increase students' enthusiasm about ecotoxicology, driving better learning experiences.


Asunto(s)
Neurotoxinas , Compuestos de Azufre , Contaminantes Químicos del Agua , Humanos , Animales , Invertebrados , Piridinas , Larva , Contaminantes Químicos del Agua/toxicidad , Contaminantes Químicos del Agua/análisis , Daphnia
13.
Rev. neurol. (Ed. impr.) ; 78(4)16-28 feb., 2024. tab, graf
Artículo en Español | IBECS | ID: ibc-230631

RESUMEN

Objetivo Determinar las características clínicas, electroencefalográficas, terapéuticas y evolutivas de una serie de pacientes oncopediátricos con convulsiones sintomáticas agudas. Pacientes y métodos Efectuamos un análisis descriptivo retrospectivo y prospectivo de registros clínicos de niños oncopediátricos evaluados por neurología en el Centro Ambulatorio Integral de Pacientes Hematooncológicos durante 2017-2021. Incluimos a niños de 1 mes a 17 años con tumores intracraneales y extracraneales que presentaron convulsiones sintomáticas agudas (CSA). Definimos convulsión sintomática aguda según la clasificación de la Liga Internacional contra la Epilepsia de 2010. Clasificamos las crisis epilépticas según la clasificación de la Liga Internacional contra la Epilepsia de 2017. Excluimos a todo paciente con diagnóstico de epilepsia previa y de episodios paroxísticos no epilépticos. Resultados Analizamos 44 casos, con una mediana de 4 años (rango: 1 mes-17 años) y una media de 5,75 meses (rango: 1 mes-11 meses) y 8,33 años (2-17 años). Registramos como principales etiologías la neurotoxicidad y el contexto posquirúrgico, con cuatro pacientes asociados a disnatremias y dos a hipertensión endocraneana. Se realizaron 41 electroencefalogramas, con resultados intercríticos con anormalidades en el ritmo de base, pero sin focos ni paroxismos. No hubo registros críticos. Las convulsiones focales fueron 25 (56,8%), y las generalizadas, 19 (43,18%). El levetiracetam fue el fármaco más utilizado para el tratamiento agudo. Conclusiones Nuestra cohorte muestra que las CSA, en esta población, no evidencian diferencias considerables entre convulsiones focales motoras y generalizadas, y ocurren mayormente en un contexto neurotóxico y posquirúrgico. También se registraron disnatremias e hipertensión endocraneana asociadas a CSA. Los electroencefalogramas poscrisis fueron sin focos o paroxismos y con evolución de las crisis. (AU)


AIM To determine clinical, electroencephalographic, therapeutic and evolutive characteristics of a series of oncopediatric patients with acute symptomatic seizures. PATIENTS AND METHODS We performed a retrospective and prospective descriptive analysis of clinical records of oncopediatric children evaluated by neurology at the comprehensive outpatient Center for Hemato-Oncological Patients during 2017-2021. We included children aged one month to 17 years with intracranial and extracranial tumors who presented with acute symptomatic seizure (ASC). We defined acute symptomatic seizure according to the 2010 International League Against Epilepsy. We classified seizures according to 2017 International League Against Epilepsy classification. We excluded any patient with a diagnosis of previous epilepsy and non-epileptic paroxysmal episodes. RESULTS We analyzed 44 cases with a median of 4 years (range: 1 month-17 years) and mean of 5.75 months (range: 1 month-11 months) and 8.33 years (2-17 years). The main etiologies were neurotoxicity and post-surgical context. Four patients presented dysnatremias and two associated with endocranial hypertension. Forty-one electroencephalograms were performed with intercritical results with abnormalities in the baseline rhythm, but without foci or paroxysms. There were no critical recordings. Focal seizures were 25 (56.8%) and generalized seizures 19 (43.18%). Levetiracetam was the most commonly used drug for acute management. CONCLUSIONS Our cohort shows that ASC, in this population, do not show considerable differences between focal motor and generalized seizures and occur mostly in neurotoxic and post-surgical contexts. Dysnatremias and endocranial hypertension associated with ASC were also recorded. Postcrisis electroencephalograms were without foci or paroxysms and good seizure evolution. (AU)


Asunto(s)
Humanos , Masculino , Femenino , Lactante , Preescolar , Niño , Adolescente , Convulsiones/etiología , Oncología Médica , Pediatría , Periodo Posoperatorio , Electroencefalografía , Neurotoxinas , Terapéutica , Estudios Retrospectivos , Epidemiología Descriptiva , Estudios Prospectivos
14.
Sci Transl Med ; 16(735): eadk1867, 2024 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-38381847

RESUMEN

Snakebite envenoming is a major global public health concern for which improved therapies are urgently needed. The antigenic diversity present in snake venom toxins from various species presents a considerable challenge to the development of a universal antivenom. Here, we used a synthetic human antibody library to find and develop an antibody that neutralizes long-chain three-finger α-neurotoxins produced by numerous medically relevant snakes. Our antibody bound diverse toxin variants with high affinity, blocked toxin binding to the nicotinic acetylcholine receptor in vitro, and protected mice from lethal venom challenge. Structural analysis of the antibody-toxin complex revealed a binding mode that mimics the receptor-toxin interaction. The overall workflow presented is generalizable for the development of antibodies that target conserved epitopes among antigenically diverse targets, and it offers a promising framework for the creation of a monoclonal antibody-based universal antivenom to treat snakebite envenoming.


Asunto(s)
Antivenenos , Mordeduras de Serpientes , Humanos , Animales , Ratones , Antivenenos/química , Mordeduras de Serpientes/tratamiento farmacológico , Neurotoxinas/toxicidad , Anticuerpos ampliamente neutralizantes , Venenos de Serpiente
15.
Cells ; 13(3)2024 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-38334622

RESUMEN

Neuronal cell death is a key mechanism involved in the development and exacerbation of Parkinson's disease (PD). The excessive production of reactive oxygen species (ROS) is a major cause leading to neuronal death; therefore, compounds that prevent oxidative stress-dependent neuronal death may be promising as a preventive method for PD. Ergothioneine is a natural amino acid with antioxidant properties, and its protective functions in the body are attracting attention. However, there has been no investigation into the protective functions of ergothioneine using in vivo and in vitro PD models. Thus, in this study, we analyzed the efficacy of ergothioneine against 6-hydroxydopamine (6-OHDA)-dependent neuronal cell death using immortalized hypothalamic neurons (GT1-7 cells). First, we found that ergothioneine prevents 6-OHDA-dependent neuronal cell death by suppressing ROS overproduction in GT1-7 cells. The cytoprotective effect of ergothioneine was partially abolished by verapamil, an inhibitor of OCTN1, which is involved in ergothioneine uptake. Furthermore, ergothioneine-rich Rice-koji (Ergo-koji) showed cytoprotective and antioxidant effects similar to those of ergothioneine. Taken together, these results suggest that ergothioneine or foods containing ergothioneine may be an effective method for preventing the development and progression of PD.


Asunto(s)
Ergotioneína , Ergotioneína/farmacología , Ergotioneína/metabolismo , Oxidopamina/farmacología , Especies Reactivas de Oxígeno/metabolismo , Neurotoxinas/farmacología , Muerte Celular , Antioxidantes/farmacología , Antioxidantes/metabolismo
17.
J Vis Exp ; (203)2024 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-38284533

RESUMEN

A variety of biological toxins can be present at harmful levels in the aquatic environment. Cyanobacteria are a diverse group of prokaryotic microorganisms that produce cyanotoxins in the aquatic environment. These biotoxins can be hepatotoxins, dermatoxins, or neurotoxins and can affect fish and mammals. At high levels, these compounds are fatal. At non-lethal levels, they act insidiously and affect immune cell functions. Algae-produced biotoxins include microcystin and anatoxin A. Aquatic animals can also ingest material contaminated with botulinum neurotoxin E (BoNT/E) produced by Clostridium botulinum, also resulting in death or decreased immune functions. Zebrafish can be used to study how toxins affect immune cell functions. In these studies, toxin exposures can be performed in vivo or in vitro. In vivo studies expose the zebrafish to the toxin, and then the cells are isolated. This method demonstrates how the tissue environment can influence leukocyte function. The in vitro studies isolate the cells first, and then expose them to the toxin in culture wells. The leukocytes are obtained by kidney marrow extraction, followed by density gradient centrifugation. How leukocytes internalize pathogens is determined by endocytic mechanisms. Flow cytometry phagocytosis assays demonstrate if endocytic mechanisms have been altered by toxin exposure. Studies using isolated leukocytes to determine how toxins cause immune dysfunction are lacking. The procedures described in this article will enable laboratories to use zebrafish to study the mechanisms that are impacted when an environmental toxin decreases endocytic functions of immune cells.


Asunto(s)
Cianobacterias , Toxinas Biológicas , Animales , Pez Cebra , Neurotoxinas , Leucocitos , Mamíferos
18.
Plant Physiol Biochem ; 207: 108388, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38295528

RESUMEN

Grass pea has the potential to become a miracle crop if the stigma attached to it as a toxic plant is ignored. In light of the following, we conducted transcriptome analyses on the high and low ODAP-containing cultivars i.e., Nirmal and Bidhan respectively in both normal and salt stress conditions. In this study, genes that work upstream and downstream to ß-ODAP have been found. Among these genes, AAO3 and ACL5 were related to ABA and polyamine biosynthesis, showing the relevance of ABA and polyamines in boosting the ß-ODAP content in Nirmal. Elevated ß-ODAP levels in salt stress-treated Bidhan may have evolved tolerance by positively regulating the expression of genes involved in phenylpropanoid and jasmonic acid biosynthesis. Although the concentration of ß-ODAP in Bidhan increased under salt stress, it was lower than in stress-treated Nirmal. Despite this, the expression of stress-related genes that work downstream to ß-ODAP was found higher in stress-treated Bidhan. This could be because stress-treated Nirmal has lower GSH, proline, and higher H2O2, resulting in the development of severe oxidative stress. Overall, our research not only identified new genes linked with ß-ODAP, but also revealed the molecular mechanism by which a low ß-ODAP-containing cultivar developed tolerance against salinity stress.


Asunto(s)
Aminoácidos Diaminos , Lathyrus , Lathyrus/genética , Lathyrus/metabolismo , Neurotoxinas/análisis , Neurotoxinas/metabolismo , Aminoácidos Diaminos/análisis , Aminoácidos Diaminos/metabolismo , Peróxido de Hidrógeno/metabolismo , Estrés Salino/genética
19.
Toxins (Basel) ; 16(1)2024 01 07.
Artículo en Inglés | MEDLINE | ID: mdl-38251246

RESUMEN

Botulinum neurotoxin A (BoNT/A) is a potent neurotoxin that silences cholinergic neurotransmission through the cleavage of the synaptic protein SNAP-25. Previous studies have shown that, in addition to its paralytic effects, BoNT/A can inhibit sensory nerve activity. The aim of this study was to identify how BoNT/A inhibits afferent signalling from the bladder. To investigate the role of SNAP-25 cleavage in the previously reported BoNT/A-dependent inhibition of sensory signalling, we developed a recombinant form of BoNT/A with an inactive light chain, rBoNT/A (0), unable to paralyse muscle. We also developed recombinant light chain (LC)-domain-only proteins to better understand the entry mechanisms, as the heavy chain (HC) of the protein is responsible for the internalisation of the light chain. We found that, despite a lack of catalytic activity, rBoNT/A (0) potently inhibited the afferent responses to bladder distension to a greater degree than catalytically active rBoNT/A. This was also clear from the testing of the LC-only proteins, as the inactive rLC/A (0) protein inhibited afferent responses significantly more than the active rLC/A protein. Immunohistochemistry for cleaved SNAP-25 was negative, and purinergic and nitrergic antagonists partially and totally reversed the sensory inhibition, respectively. These data suggest that the BoNT/A inhibition of sensory nerve activity in this assay is not due to the classical well-characterised 'double-receptor' mechanism of BoNT/A, is independent of SNAP25 cleavage and involves nitrergic and purinergic signalling mechanisms.


Asunto(s)
Toxinas Botulínicas Tipo A , Transducción de Señal , Neurotoxinas , Bioensayo , Músculos
20.
Toxins (Basel) ; 16(1)2024 01 12.
Artículo en Inglés | MEDLINE | ID: mdl-38251259

RESUMEN

Tetrodotoxin (TTX), an extremely potent low-molecular-weight neurotoxin, is widespread among marine animals including ribbon worms (Nemertea). Previously, studies on the highly toxic palaeonemertean Cephalothrix cf. simula showed that toxin-positive structures are present all over its body and are mainly associated with glandular cells and epithelial tissues. The highest TTXs concentrations were detected in a total extract from the intestine of the anterior part of the body and also in a total extract from the proboscis. However, many questions as to the TTXs distribution in the organs of the anterior part of the worm's body and the functions of the toxins in these organs are still unanswered. In the present report, we provide additional results of a detailed and comprehensive analysis of TTXs distribution in the nemertean's proboscis, buccal cavity, and cephalic gland using an integrated approach including high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), confocal laser scanning microscopy with anti-TTX antibodies, light and electron microscopies, and observations of feeding behavior. For the proboscis, we have found a TTXs profile different from that characteristic of other organs and tissues. We have also shown for the first time that the major amount of TTXs is localized in the anterior part of the proboscis that is mainly involved in hunting. TTX-containing glandular cells, which can be involved in the prey immobilization, have been found in the buccal cavities of the nemerteans. A significant contribution of the cephalic gland to the toxicity of this animal has been shown for the first time, and the role of the gland is hypothesized to be involved not only in protection against potential enemies but also in immobilizing prey. The data obtained have made it possible to extend the understanding of the role and features of the use of TTXs in the organs of the anterior part of nemertean's body.


Asunto(s)
Neurotoxinas , Espectrometría de Masas en Tándem , Animales , Tetrodotoxina , Cromatografía Líquida de Alta Presión , Células Epiteliales
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