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1.
Sci Total Environ ; 803: 149858, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-34482148

RESUMO

Brevetoxins (PbTx) are a well-recognized group of neurotoxins associated with harmful algal blooms, and specifically recurrent "Florida Red Tides," in marine waters that are linked to impacts on both human and ecosystem health including well-documented "fish kills" and marine mammal mortalities in affected coastal waters. Understanding mechanisms and pathways of PbTx toxicity enables identification of relevant biomarkers to better understand these environmental impacts, and improve monitoring efforts, in relation to this toxin. Toward a systems-level understanding of toxicity, and identification of potential biomarkers, high-resolution magic angle spinning nuclear magnetic resonance (HRMAS NMR) was utilized for metabolic profiling of zebrafish (Danio rerio) embryos, as an established toxicological model, exposed to PbTx-2 (the most common congener in marine waters). Metabolomics studies were, furthermore, complemented by an assessment of the toxicity of PbTx-2 in embryonic stages of zebrafish and mahi-mahi (Coryphaena hippurus), the latter representing an ecologically and geographically relevant marine species of fish, which identified acute embryotoxicity at environmentally relevant (i.e., parts-per-billion) concentrations in both species. HRMAS NMR analysis of intact zebrafish embryos exposed to sub-lethal concentrations of PbTx-2 afforded well-resolved spectra, and in turn, identification of 38 metabolites of which 28 were found to be significantly altered, relative to controls. Metabolites altered by PbTx-2 exposure specifically included those associated with (1) neuronal excitotoxicity, as well as associated neural homeostasis, and (2) interrelated pathways of carbohydrate and energy metabolism. Metabolomics studies, thereby, enabled a systems-level model of PbTx toxicity which integrated multiple metabolic, molecular and cellular pathways, in relation to environmentally relevant concentrations of the toxin, providing insight to not only targets and mechanisms, but potential biomarkers pertinent to environmental risk assessment and monitoring strategies.


Assuntos
Ecossistema , Peixe-Zebra , Animais , Humanos , Espectroscopia de Ressonância Magnética , Toxinas Marinhas , Metabolômica , Oxocinas
2.
Emerg Med Clin North Am ; 40(1): 119-133, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34782083

RESUMO

Scombroid poisoning, systemic mastocytosis, and hereditary alpha tryptasemia all present with episodes that resemble allergic reactions. Knowledge regarding systemic mastocytosis and hereditary alpha tryptasemia is quickly evolving. Epidemiology, pathophysiology, and strategies to identify and diagnose are discussed. Evidence-based management in the emergency setting and beyond is also explored and summarized. Key differences are described between these events and allergic reactions.


Assuntos
Angioedema/diagnóstico , Hipersensibilidade/diagnóstico , Toxinas Marinhas/biossíntese , Angioedema/fisiopatologia , Mimetismo Biológico , Humanos , Hipersensibilidade/fisiopatologia , Toxinas Marinhas/metabolismo , Triptases/análise , Triptases/deficiência
3.
Environ Pollut ; 292(Pt A): 118354, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34648839

RESUMO

Contamination of microcystins (MCs) in plant-soil system have become a serious problem worldwide, however, it remains largely unknown how to alleviate the potential risk of consuming MCs-contaminated plants. In the present study, attapulgite, biochar and peat were used as soil amendments to reduce MCs bioaccumulation in lettuce. Lettuce irrigated with 10 µg L-1 microcystin-LR (MC-LR) were growing in two different kinds of soils with or without soil amendments. Results showed that all soil amendments effectively reduced MC-LR bioaccumulation in lettuce roots and leaves. Compared with the control treatment, the MC-LR concentrations in leaves in treatments with attapulgite, biochar and peat decreased by 41.5%, 30.6%, 57.0% in soil A and 38.9%, 43.2%, 54.7% in soil B, respectively. Peat application was most effective in reducing MC-LR bioaccumulation. The decreased soil free MC-LR concentrations were positively correlated with MC-LR concentrations in lettuce, indicating decreased bioavailability of MC-LR by soil amendments. It is noteworthy that soil total MC-LR concentration in peat treatment significantly decreased by 33.3% and 29.4% in soil A and soil B, respectively, compared with the controls. According to the results from high-throughput sequencing, peat amendment increased the α-diversity of soil bacterial community and boosted the abundance of Sphingomonas and Methylobacillus (dozens of MC-degrading bacteria belong to these genera). This was in line with the results of soil total MC-LR concentration. It can be speculated that peat application directly and/or indirectly promoted microbial degradation of MC-LR in soils. This work proposed an effective way to alleviate the potential risks of MCs contamination in plant-soil system.


Assuntos
Alface , Microcistinas , Bioacumulação , Alface/metabolismo , Toxinas Marinhas , Microcistinas/metabolismo , Solo
4.
Chemosphere ; 286(Pt 3): 131950, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34426274

RESUMO

In this study, a cyclic process of adsorption and persulfate (PS) oxidation-driven regeneration using FeCl3-activated biochar (FA-BC) was suggested as a novel remediation process to remove microcystin-LR (MC-LR) from water. For enhancing overall treatment efficiency and cost effectiveness, the impacts of temperature on adsorption and PS oxidation-driven regeneration were investigated. The increase of temperature resulted in the increase of MC-LR adsorption rate on FA-BC due to the enhanced MC-LR diffusivity in water. Moreover, the MC-LR oxidation and PS reaction rates during the PS regeneration on FA-BC were remarkably improved by factors of 3.4 and 3.5 with increasing temperature from 20 °C to 50 °C. Both diffusion and desorption of MC-LR from FA-BC were thought to be the key factors for controlling the MC-LR oxidation rate during the PS regeneration of MC-LR. In addition, the decrease of pH (from 10 to 4) and increase of PS concentration (from 100 to 400 mg/L) enhanced the regeneration efficiency for MC-LR-spent FA-BC. The four cycles of adsorption-PS regeneration (200 mg/L PS, pH 6, and 50 °C) resulted in 92.81% regeneration efficiency in DI water and 82.89% in lake water. However, the four cycles of adsorption-PS regeneration led to the reduction of surface area (from 835 to 413 m2/g), oxidation of carbon surface and slight reduction of Fe0 on FA-BC. In overall, the cyclic adsorption-PS regeneration at higher temperature could provide practical reuse of FA-BC for cost-effective treatment of aqueous MC-LR.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Adsorção , Carvão Vegetal , Toxinas Marinhas , Microcistinas , Água , Poluentes Químicos da Água/análise
5.
Talanta ; 236: 122864, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34635246

RESUMO

Real time controllable assembling/aptasensing approach via plasmonic graphene oxide (GO) nanocomposites has been firstly proven to simultaneously give tuning of micro-nano structure of plasmonic GO and ultrasensitive detection of MC-LR toxin. In order to fabricate the assembly, a high-quality hollow triangular nanoplate AgClAu:p-GO (HTNP AgClAu:p-GO) can act as a template; furthermore, we combine DNA-hybridization with biotin-strepavidin binding protocol for tuning the HTNP AgClAu:p-GO assemblies from networks to laminar structure, and simultaneously loading Raman reporters into the assemblies. The dynamic assembling process can be utilized as a real time SERS aptasensor for detecting MC-LR due to ratiometric introduction of MC-LR toxin inhibiting formation of plasmonic p-GO assembly via toxin/aptamer bioconjugation and causing reverse alteration of SERS signal for giving ultrasensitive SERS detection of MC-LR. A detection limit of 6.3pM with a wide linear range from 10pM to 5 nM can be achieved. When the aptasensor has been applied in real samples, the real time assembling/aptasensing approach shows recoveries from 98% to 103% with relative standard deviation (RSD) lower than 3%, expecting that one-step nanofabrication and sensing strategy can be extended to in-field test of environmental contaminants.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Grafite , Limite de Detecção , Toxinas Marinhas , Microcistinas
6.
Talanta ; 236: 122880, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34635260

RESUMO

A novel aptamer-functionalized metal-organic framework nanofibrous composite (viz. PAN/UiO@UiO2-N3-aptamer) with a high aptamer coverage density was proposed based on the electrospinning and seeded growth method, and used for specific affinity recognition of trace Microcystin-LR (MC-LR). Heterobifunctional ligand was used to modify the metal-organic framework nanoparticles (MOF NPs) surface, which could passivate the MOF surface with respect to unmodified DNA, followed by coupling massive aptamers on MOF of the solid-phase microextraction (SPME) fiber using click chemistry. Characterizations including morphology, spectra analysis, mechanical stability, binding capacity and specificity were fulfilled. Applied to the analysis of MC-LR, the good selective and sensitive recognition were obtained with the detection limit as low as 0.003 ng/mL, which was better than most non-specific SPME or solid-phase extraction (SPE) protocols. The stability and reproducibility were acceptable, and the intra-day, inter-day and column-to-column relative standard deviations (RSDs) for the recovery of MC-LR were gained in the range from 2.5% to 14.3%, respectively. Satisfactory recoveries of MC-LR in environmental water samples were measured as 96.3 ± 4.7% - 98.9 ± 2.7% (n = 3) in tap water, 94.4 ± 2.5% - 96.1 ± 3.5% (n = 3) in pond water, and 97.0 ± 2.1% - 97.9 ± 3.1% (n = 3) in river water, respectively. This work demonstrated that the electrospun nanofibrous composite with massive aptamers would be a better alternative for ultra-trace MC-LR detection with good selectivity, matrix-resistance ability and high resolution.


Assuntos
Aptâmeros de Nucleotídeos , Estruturas Metalorgânicas , Nanofibras , Toxinas Marinhas , Microcistinas , Reprodutibilidade dos Testes
7.
J Hazard Mater ; 421: 126798, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34388926

RESUMO

Domoic acid (DA) is a major marine neurotoxin, occurs frequently in most of the world's coastlines and seriously threatens ecosystem and public health. However, information on its biotransformation process in coastal anaerobic environments remains unclear. In this study, the underlying mechanism of anaerobic biotransformation of DA by marine consortium GLY was investigated using the combination of liquid chromatography-high-resolution Orbitrap mass spectrometry and comparative metatranscriptomics analysis. The results demonstrated that DA could be cometabolically biotransformed under anaerobic conditions with pseudo-first-order reaction. Anaerobic biotransformation pathway of DA was clarified, including decarboxylation, dehydrogenation, carboxylation activation with CoA and multiple ß-oxidation steps occurring at aliphatic side chain, which facilitated DA detoxification. Furthermore, anaerobic cometabolic biotransformation mechanism of glycine-DA by consortium GLY was established for the first time, a number of genes related to the metabolic pathways of glycine fermentation, fatty acid synthesis and ß-oxidation were responded in the consortium GLY transcriptome and involved in the anaerobic biotransformation of DA. This study could deepen understanding of interaction mechanism between toxin DA and marine microorganisms, which provides a new insight into the DA fate and its effects on benthic microbial community in marine environments.


Assuntos
Ecossistema , Toxinas Marinhas , Anaerobiose , Biotransformação , Ácido Caínico/análogos & derivados
8.
Talanta ; 237: 122897, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34736713

RESUMO

The spectroscopic ellipsometry (SE), and attenuated internal reflection spectroscopic ellipsometry (TIRE) are promising methods in label-free biosensing applications. An ellipsometer running under surface plasmon resonance (SPR) conditions has unique advantages over other SPR-based methods in terms of sensitivity and real-time/label-free measurement capability. In this study, both SE and TIRE-based brevetoxin B (BTX) sensors were developed using two anti-BTX aptamers reported before. A new aptamer sequence was also derived from these two antiBTX aptamers using predictive modeling tools and an exclusion method. All three antiBTX aptamers' analytical performances were quite competitive in terms of both detecting range and detection limits. However, the selectivity of the previously reported aptamers against analogs of BTX was poor at low detection ranges, especially for okadaic acid. Furthermore, the selectivity of the derived aptamer was lower than its predecessors. The sensors were capable of detecting BTX in the range of 0.05 nM-1600 nM in the TIRE and 0.5 nM-2000 nM in the SE configuration. The detection limits of the sensors were 1.48 nM (1.32 ng/mL) and 0.80 nM (0.72 ng/mL) for SE and TIRE configurations, respectively. Both configurations have been used successfully to detect BTX standards spiked into real fish and shrimp samples.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Animais , Toxinas Marinhas , Oxocinas , Alimentos Marinhos/análise , Análise Espectral , Ressonância de Plasmônio de Superfície
9.
J Hazard Mater ; 421: 126690, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34315019

RESUMO

Shellfish toxins are derived from harmful algae and are easily accumulated in environment and marine food through the food chain, exposing high risks on human health. Preliminary rapid screening is one of the most effective monitoring ways to reduce the potential risks; however, the traditional methods encounter with many limitations, such as complicated procedures, low sensitivity and specificity, and ethical problems. Alternatively, bioaffinity sensors are proposed and draw particular attention. Among them, the aptasensors are springing up and emerging as superior alternatives in recent years, exhibiting high practicability to analyze shellfish toxins in real samples in the marine food chain. Herein, the latest research progresses of aptasensors towards shellfish toxins in the marine food chain in the past five years was reviewed for the first time, in terms of the aptamers applied in these aptasensors, construction principles, signal transduction techniques, response types, individual performance properties, practical applications, and advantages/disadvantages of these aptasensors. Synchronously, critical discussions were given and future perspectives were prospected. We hope this review can serve as a powerful reference to promote further development and application of aptasensors to monitor shellfish toxins, as well as other analytes with similar demands.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Contaminação de Alimentos/análise , Toxinas Marinhas/análise , Cadeia Alimentar , Humanos , Frutos do Mar
10.
Ecotoxicol Environ Saf ; 227: 112905, 2021 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-34673413

RESUMO

Diarrheic shellfish poisoning (DSP) toxins are widely distributed over the world, causing diarrhea, vomiting, and even tumor in human. However, bivalves, the main carrier of the DSP toxins, have some tolerant mechanisms to DSP toxins, though it remains unclear. In this study, we scrutinized the role of Jun N-terminal kinases (JNK) in tolerance of DSP toxins and the relationship between JNK, apoptosis and nuclear factor E2-related factor/antioxidant response element (Nrf2/ARE) pathways. We found that the phosphorylated level of JNK protein was significantly increased both in hemocytes (6 h) and gills (3 h) of the mussel Perna viridis after short-term exposure to DSP toxins-producing dinoflagellate Prorocentrum lima. Exposure of P. lima induced oxidative stress in mussels. Hemocytes and gills displayed different sensitivities to the cytotoxicity of DSP toxins. Exposure of P. lima activated caspase-3 and induced apoptosis in gills but did not induce caspase-3 and apoptosis in hemocytes. The short-term exposure of P. lima could activate Nrf2/ARE signaling pathway in hemocytes (6 h), while longer-term exposure could induce glutathione reductase (GR) expression in hemocytes (96 h) and glutathione-S-transferases (GST) in gills (96 h). Based on the phylogenetic tree of Nrf2, Nrf2 in P. viridis was closely related to that in other mussels, especially Mytilus coruscus, but far from that in Mus musculus. The most likely phosphorylated site of Nrf2 in the mussels P. viridis is threonine 504 for JNK, which is different from that in M. musculus. Taken all together, the tolerant mechanism of P. viridis to DSP toxins might be involved in JNK and Nrf2/ARE signaling pathways, and JNK play a key role in the mechanism. Our findings provide a new clue to further understand tolerant mechanisms of bivalves to DSP toxins.


Assuntos
Dinoflagelados , Perna (Organismo) , Animais , Humanos , Sistema de Sinalização das MAP Quinases , Toxinas Marinhas/toxicidade , Camundongos , Filogenia
11.
Analyst ; 146(22): 7005-7020, 2021 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-34679153

RESUMO

An anisotropic plasmonic sheet-core-satellite (PSCS) superstructure can be controlled via competitive binding between aptamer/MC-LR conjugation and aptamer-ssDNA hybridization. SERS nanotags can be incorporated into anisotropic plasmonic sheet-cores, e.g., pGO/nanorods, or pGO/hollow AgCl : Au nanoplates so as to fabricate an aptasensor for "ON-OFF" detection of MC-LR toxin. Preparing a PSCS superstructure and detection of toxin can be simultaneously completed so as to simplify the detection procedure of MC-LR toxin. Detection sensitivity of MC-LR toxin can be optimized by controlling aspect ratios or hollow interiors of plasmonic core nanoparticles. Herein, a limit of detection (0.635 pM) with a wide linear range from 1 pM to 10 nM can be obtained via optimized PSCS of pGO/nanorod/dotnanotags. When the aptasensor was tested in real samples, the PSCS shows excellent recoveries from 96.6% to 104.5% with relative standard deviation (RSD) lower than 2.89% in spiked reservoir samples. It can be predicted that a one-step facile nanofabrication/aptasensing approach would be extensively applied for rapid detection of some other environmental contaminants.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Limite de Detecção , Toxinas Marinhas , Microcistinas
12.
Ecotoxicol Environ Saf ; 227: 112919, 2021 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-34715501

RESUMO

Microcystin-LR (MC-LR) is an intracellular toxin with multi-organ toxicity and the testis is one of its important target organs. Although there is increasing research on MC-LR in male reproductive toxicity, the association between DNA damage and autophagy induced by MC-LR in male germ cells are still unclear. Therefore, it is important to explore the mechanism of MC-LR-induced DNA damage and the role of the activated ATM/p53 signaling pathway in testicular toxicity. The present study showed that MC-LR exposure significantly reduced gonadal index and induced pathological damage of the testes in mice. In addition, MC-LR increased the oxidative stress-related indicator hydroxyl radical, accompanied by increased levels of DNA damage-related indicators gamma-H2AX, 8-hydroxy-2'-deoxyguanosine, the olive tail moment (OTM) and DNA content of comet tail (TailDNA%) in trailing cells. Moreover, MC-LR activated the ATM/p53 pathway by enhancing the phosphorylation levels of ATM, CHK2 and p53 proteins, and then led to cell autophagy, ultimately triggering disrupted testicular cell arrangement, reduced sperm count and spermatogenic cell shedding. Importantly, after pretreatment with the antioxidant NAC, the expression levels of DNA damage-related indicators and the extent of damage in male germ cells were significantly reduced. Furthermore, pretreatment with the ATM inhibitor KU55933 could reduce the occurrence of autophagy and mitigate testicular toxicity of MC-LR through inhibiting the activation of the ATM/p53 pathway. These results indicate that MC-LR-induced oxidative stress can activate the DNA damage-mediated ATM/p53 signalling pathway to induce autophagy in male germ cells. This study provides a novel insight to further clarify the reproductive toxicity caused by MC-LR and to protect male reproductive health.


Assuntos
Apoptose , Proteína Supressora de Tumor p53 , Animais , Autofagia , Dano ao DNA , Células Germinativas/metabolismo , Masculino , Toxinas Marinhas , Camundongos , Microcistinas , Estresse Oxidativo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
13.
Ecotoxicol Environ Saf ; 227: 112925, 2021 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-34717216

RESUMO

Microcystin-LR (MC-LR) is one of the most worldwide harmful cyanobacterial toxins. A lots of antibodies against MC-LR have been generated and characterized. However, the knowledge about the epitopes of MC-LR was still limited. The objective of this study was to analyze the epitopes of MC-LR and demonstrate the binding mode of MC-LR with its antibody. The variable genes of a mouse hybridoma cell line (Mab5H1-3B3) raised against MC-LR have been cloned and assembled in a single chain variable fragment (scFv), and then soluble expressed in E.coli BL21. Based on the scFv, the IC50 and IC10 for MC-LR were determined to be 7.45 nM and 0.30 nM by competitive ELISA. And the scFv also showed 115% and 112% cross-reactivities to MC-RR and MC-YR, and 59% to MC-LA. By molecular docking, the binding mode between MC-LR and its scFv was demonstrated. A hydrogen bond interaction was observed between the carbonyl group of Adda5 residue of MC-LR and its scFv, and the guanidyl group of Arg4 residue and phenyl group of Adda5 residue of MC-LR were also involved in the interaction. These predicted epitopes were supported by antibody cross-reactivity data. By comparing the antibody informatics of MC-LR scFv with its predicted paratopes, VH-CDR1 was crucial for MC-LR binding, and its specificity could be tuned by engineering in Vκ-CDR1 and Vκ-CDR3. These information would be useful for the hapten design for microcystins or improving the properties of MC-LR scFv in vitro.


Assuntos
Microcistinas , Animais , Ensaio de Imunoadsorção Enzimática , Epitopos , Toxinas Marinhas , Camundongos , Simulação de Acoplamento Molecular
14.
Anal Chim Acta ; 1185: 339078, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34711309

RESUMO

An ultrasensitive photoelectrochemical (PEC) immunosensor based on gold nanoclusters (AuNCs) with 11-mercaptoundecanoic acid (MUA) ligands was fabricated for determination of microcystin-LR (MC-LR). The PEC immunosensor was developed by loading the monoclonal MC-LR antibody (Ab) to the MUA-AuNCs modified gold electrodes. After different measurement conditions being optimized, silver nanoparticles (AgNPs), gold nanorods (AuNRs), graphene oxide (GO) and carboxyl-functionalized graphene oxide (cGO) were introduced into MUA-AuNCs to enhance the sensing properties. The experimental result revealed that the sensitivity of PEC immunosensors was enhanced by both their photoelectrochemical properties and antibody loading properties with dependent relationship, which was different from the enhancement strategy of PEC sensors based on redox reactions. Among different hybrid nanocomposites, MUA-AuNCs/cGO not only improved the photoelectrochemical properties, but also loaded more antibodies for sensing, which resulted in best sensing performance. Thus, a universal method was proposed to enhance the sensing performance of PEC immunosensors based on impedance changes. Finally, MUA-AuNCs/cGO based PEC immunosensors exhibited a wide linear range of 0.001 nM-1000 nM with low detection limit of 0.011 pM (S/N = 3) for MC-LR determination. Meanwhile, the designed PEC immunosensors showed high selectivity, reproducibility and specificity, which provided the promising applications in aquatic environment.


Assuntos
Técnicas Biossensoriais , Grafite , Nanopartículas Metálicas , Técnicas Eletroquímicas , Ouro , Imunoensaio , Limite de Detecção , Toxinas Marinhas , Microcistinas , Reprodutibilidade dos Testes , Prata
15.
Anal Methods ; 13(38): 4345-4353, 2021 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-34622887

RESUMO

Okadaic acid (OA) is one of the marine toxins that are widely distributed and harmful to humans. However, the current detection methods for OA involve complex procedures, need long detection time, and rely on large-scale laboratory equipment. In this work, a multi-channel handheld automatic spectrometer (MHAS) based on a spectral sensor was developed with the advantages of small size, simple operation and low cost. It could achieve rapid detection within 30 s and a wide spectral detection range of 470-780 nm with a broadband LED as the light source and a microplate containing 8 wells as a sample cell. Moreover, through the combination of gold nanoparticles (AuNPs) and aptamer-OA34, a highly sensitive and rapid system for OA detection was established with a LOD of 1.80 µg L-1 and a wide detection range of 20-10 000 µg L-1, which is comparable to a microplate reader. Compared with other studies, the proposed MHAS realized rapid on-site detection of OA with a wider detection range, shorter detection time and higher portability. Therefore, the MHAS promises to be a stable and efficient optical detection instrument for on-site detection in the fields of food safety, disease diagnosis and environmental monitoring.


Assuntos
Ouro , Nanopartículas Metálicas , Humanos , Toxinas Marinhas , Ácido Okadáico , Refratometria
16.
J Agric Food Chem ; 69(38): 11322-11335, 2021 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-34533950

RESUMO

Azaspiracids (AZAs) are a group of biotoxins produced by the marine dinoflagellates Azadinium and Amphidoma spp. that can accumulate in shellfish and cause food poisoning in humans. Of the 60 AZAs identified, levels of AZA1, AZA2, and AZA3 are regulated in shellfish as a food safety measure based on occurrence and toxicity. Information about the metabolism of AZAs in shellfish is limited. Therefore, a fraction of blue mussel hepatopancreas was made to study the metabolism of AZA1-3 in vitro. A range of AZA metabolites were detected by liquid chromatography-high-resolution tandem mass spectrometry analysis, most notably the novel 22α-hydroxymethylAZAs AZA65 and AZA66, which were also detected in naturally contaminated mussels. These appear to be the first intermediates in the metabolic conversion of AZA1 and AZA2 to their corresponding 22α-carboxyAZAs (AZA17 and AZA19). α-Hydroxylation at C-23 was also a prominent metabolic pathway, producing AZA8, AZA12, and AZA5 as major metabolites of AZA1-3, respectively, and AZA67 and AZA68 as minor metabolites via double-hydroxylation of AZA1 and AZA2, but only low levels of 3ß-hydroxylation were observed in this study. In vitro generation of algal toxin metabolites, such as AZA3, AZA5, AZA6, AZA8, AZA12, AZA17, AZA19, AZA65, and AZA66 that would otherwise have to be laboriously purified from shellfish, has the potential to be used for the production of standards for analytical and toxicological studies.


Assuntos
Mytilus edulis , Compostos de Espiro , Animais , Humanos , Toxinas Marinhas , Frutos do Mar/análise
17.
Aquat Toxicol ; 239: 105950, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34474269

RESUMO

Diarrheic shellfish poisoning toxins (DSP toxins) are a set of the most important phycotoxins produced by some dinoflagellates. Studies have shown that DSP toxins have various toxicities such as genotoxicity, cytotoxicity, and immunotoxicity to bivalve mollusks. However, these toxicities appear decreasing with exposure time and concentration of DSP toxins. The underlying mechanism involved remains unclear. In this study, small RNA sequencing was performed in the digestive gland of the mussel Perna viridis after exposure to DSP toxins-producing dinoflagellate Prorocentrum lima for different time periods. The potential roles of miRNAs in response and detoxification to DSP toxins in the mussel were analyzed. Small RNA sequencing of 12 samples from 72 individuals was conducted by BGISEQ-500. A total of 123 mature miRNAs were identified, including 90 conserved miRNAs and 33 potential novel miRNAs. After exposure to P. lima, multiple important miRNAs displayed some alterations. Further miRNA target prediction revealed some important genes involved in cytoskeleton, apoptosis, complement system and immune stress. qPCR demonstrated that miR-71_5, miR-750_1 and novel_mir4 were significantly up-regulated at 6 h after exposure to P. lima, while miR-100_2 was significantly down-regulated after 96 h of exposure. Accordingly, putative target genes of these differentially expressed miRNAs experienced some changes. After 6 h of DSP toxins exposure, NHLRC2 and C1q-like were significantly down-regulated. After 96 h of DSP toxins exposure, NHLRC2 was significantly up-regulated. It is reasonable to speculate that the mussel P. viridis might respond to DSP toxins through miR-750_1, novel_mir4 and miR-71_5 regulating the expression of relevant target genes involved in apoptosis, cytoskeleton, and immune response, etc. This study might provide new clues to uncover the toxic response of bivalve to DSP toxins and lay a foundation for revealing the roles of miRNAs in the environmental adaptation in shellfish.


Assuntos
Dinoflagelados , MicroRNAs , Perna (Organismo) , Intoxicação por Frutos do Mar , Poluentes Químicos da Água , Animais , Dinoflagelados/genética , Humanos , Toxinas Marinhas/toxicidade , MicroRNAs/genética , Perna (Organismo)/genética , Poluentes Químicos da Água/toxicidade
18.
Int J Mol Sci ; 22(18)2021 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-34576099

RESUMO

We were the first to previously report that microcystin-LR (MC-LR) has limited effects within the colons of healthy mice but has toxic effects within colons of mice with pre-existing inflammatory bowel disease. In the current investigation, we aimed to elucidate the mechanism by which MC-LR exacerbates colitis and to identify effective therapeutic targets. Through our current investigation, we report that there is a significantly greater recruitment of macrophages into colonic tissue with pre-existing colitis in the presence of MC-LR than in the absence of MC-LR. This is seen quantitatively through IHC staining and the enumeration of F4/80-positive macrophages and through gene expression analysis for Cd68, Cd11b, and Cd163. Exposure of isolated macrophages to MC-LR was found to directly upregulate macrophage activation markers Tnf and Il1b. Through a high-throughput, unbiased kinase activity profiling strategy, MC-LR-induced phosphorylation events were compared with potential inhibitors, and doramapimod was found to effectively prevent MC-LR-induced inflammatory responses in macrophages.


Assuntos
Inflamação/patologia , Macrófagos/patologia , Toxinas Marinhas/toxicidade , Microcistinas/toxicidade , Animais , Biomarcadores/metabolismo , Colite/genética , Colite/patologia , Colo/efeitos dos fármacos , Colo/patologia , Sulfato de Dextrana , Modelos Animais de Doenças , Regulação da Expressão Gênica/efeitos dos fármacos , Inflamação/genética , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Naftalenos/farmacologia , Proteínas Quinases/metabolismo , Proteoma/metabolismo , Pirazóis/farmacologia , Ratos
19.
Biosensors (Basel) ; 11(9)2021 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-34562905

RESUMO

The adoption of electrochemical principles to realize on-field analytical tools for detecting pollutants represents a great possibility for food safety and environmental applications. With respect to the existing transduction mechanisms, i.e., colorimetric, fluorescence, piezoelectric etc., electrochemical mechanisms offer the tremendous advantage of being easily miniaturized, connected with low cost (commercially available) readers and unaffected by the color/turbidity of real matrices. In particular, their versatility represents a powerful approach for detecting traces of emerging pollutants such as cyanotoxins. The combination of electrochemical platforms with nanomaterials, synthetic receptors and microfabrication makes electroanalysis a strong starting point towards decentralized monitoring of toxins in diverse matrices. This review gives an overview of the electrochemical biosensors that have been developed to detect four common cyanotoxins, namely microcystin-LR, anatoxin-a, saxitoxin and cylindrospermopsin. The manuscript provides the readers a quick guide to understand the main electrochemical platforms that have been realized so far, and the presence of a comprehensive table provides a perspective at a glance.


Assuntos
Toxinas Bacterianas/análise , Monitoramento Ambiental/métodos , Análise de Alimentos/métodos , Alcaloides , Técnicas Biossensoriais , Cianobactérias , Água Doce , Toxinas Marinhas , Microcistinas , Tropanos , Uracila
20.
Harmful Algae ; 108: 102097, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34588119

RESUMO

The effects of harmful algae on bivalve physiology are complex and involve both physiological and behavioural responses. Studying those responses is essential to better describe and predict their impact on shellfish aquaculture and health risk for humans. In this study we recorded for two months the physiological response of the blue mussel Mytilus edulis from Eastern Canada to a one-week exposure to a paralytic shellfish poisoning producing dinoflagellate strain of Alexandrium catenella, isolated from the St Lawrence estuary, Canada. Mussels in a 'control' treatment were fed continuously with a non-toxic diet, while mussels in a 'starvation' treatment were fed the same non-toxic diet the first week and subsequently starved for seven weeks. Mussels in a 'toxic' treatment received A. catenella for one week before being starved until the end of the experiment. Over a two-month experiment we monitored shell and tissue growth, filtration capacity, respiration rate, byssal attachment strength, valve opening behaviour, and toxin content in tissues. Mussels fed normally on the toxic dinoflagellate and accumulated an average of 51.6 µg STXeq 100 g-1 after one week of exposure. After seven weeks of depuration, about half of the specimen showed levels around 18 µg STXeq 100 g-1. The condition index of exposed mussels ('toxic' treatment) decreased rapidly from the start as compared to mussels that received a one-week non-toxic diet ('starvation' treatment). Oxygen consumption rates increased in the 'toxic' treatment before leveling out with that of mussels from the 'starvation' treatment. Valve opening amplitude was lower in the 'toxic' treatment during and following the exposure. Average valve closure duration was higher right after the exposure, during the peak of mussel tissue intoxication. No significant change in byssal thread strength was observed through time in each treatment but less force was required to detach mussels from the 'toxic' and 'starvation' treatments. The number of byssus threads produced by mussels exposed to the toxic dinoflagellate was also lower than in the control group. These results represent advancements in our understanding of the impacts of harmful algae on bivalves and contribute to the development of mitigation measures necessary to both the safety of consumers and the sustainability of aquaculture operations.


Assuntos
Dinoflagelados , Mytilus , Intoxicação por Frutos do Mar , Animais , Toxinas Marinhas , Alimentos Marinhos
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