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Harmful Algae Mar 2021Harmful algal blooms (HABs), varying in intensity and causative species, have historically occurred throughout the Chesapeake Bay, U.S.; however, phycotoxin data are...
Harmful algal blooms (HABs), varying in intensity and causative species, have historically occurred throughout the Chesapeake Bay, U.S.; however, phycotoxin data are sparse. The spatiotemporal distribution of phycotoxins was investigated using solid-phase adsorption toxin tracking (SPATT) across 12 shallow, nearshore sites within the lower Chesapeake Bay and Virginia's coastal bays over one year (2017-2018). Eight toxins, azaspiracid-1 (AZA1), azaspiracid-2 (AZA2), microcystin-LR (MC-LR), domoic acid (DA), okadaic acid (OA), dinophysistoxin-1 (DTX1), pectenotoxin-2 (PTX2), and goniodomin A (GDA) were detected in SPATT extracts. Temporally, phycotoxins were always present in the region, with at least one phycotoxin group (i.e., consisting of OA and DTX1) detected at every time point. Co-occurrence of phycotoxins was also common; two or more toxin groups were observed in 76% of the samples analyzed. Toxin maximums: 0.03 ng AZA2/g resin/day, 0.25 ng DA/g resin/day, 15 ng DTX1/g resin/day, 61 ng OA/g resin/day, 72 ng PTX2/g resin/day, and 102,050 ng GDA/g resin/day were seasonal, with peaks occurring in summer and fall. Spatially, the southern tributary and coastal bay regions harbored the highest amount of total phycotoxins on SPATT over the year, and the former contained the greatest diversity of phycotoxins. The novel detection of AZAs in the region, before a causative species has been identified, supports the use of SPATT as an explorative tool in respect to emerging threats. The lack of karlotoxin in SPATT extracts, but detection of Karlodinium veneficum by microscopy, however, emphasizes that this tool should be considered complementary to, but not a replacement for, more traditional HAB management and monitoring methods.
Topics: Bays; Dinoflagellida; Environmental Monitoring; Harmful Algal Bloom
PubMed: 33980433
DOI: 10.1016/j.hal.2021.101993 -
International Journal of Molecular... Apr 2023Bruton's tyrosine kinase (Btk) and spleen tyrosine kinase (Syk) are major signaling proteins in human platelets that are implicated in atherothrombosis and...
Bruton's tyrosine kinase (Btk) and spleen tyrosine kinase (Syk) are major signaling proteins in human platelets that are implicated in atherothrombosis and thrombo-inflammation, but the mechanisms controlling their activities are not well understood. Previously, we showed that Syk becomes phosphorylated at S297 in glycoprotein VI (GPVI)-stimulated human platelets, which limits Syk activation. Here, we tested the hypothesis that protein kinases C (PKC) and A (PKA) and protein phosphatase 2A (PP2A) jointly regulate GPVI-induced Btk activation in platelets. The GPVI agonist convulxin caused rapid, transient Btk phosphorylation at S180 (pS180↑), Y223 and Y551, while direct PKC activation strongly increased Btk pS180 and pY551. This increase in Btk pY551 was also Src family kinase (SFK)-dependent, but surprisingly Syk-independent, pointing to an alternative mechanism of Btk phosphorylation and activation. PKC inhibition abolished convulxin-stimulated Btk pS180 and Syk pS297, but markedly increased the tyrosine phosphorylation of Syk, Btk and effector phospholipase Cγ2 (PLCγ2). PKA activation increased convulxin-induced Btk activation at Y551 but strongly suppressed Btk pS180 and Syk pS297. PP2A inhibition by okadaic acid only increased Syk pS297. Both platelet aggregation and PLCγ2 phosphorylation with convulxin stimulation were Btk-dependent, as shown by the selective Btk inhibitor acalabrutinib. Together, these results revealed in GPVI-stimulated platelets a transient Syk, Btk and PLCγ2 phosphorylation at multiple sites, which are differentially regulated by PKC, PKA or PP2A. Our work thereby demonstrated the GPVI-Syk-Btk signalosome as a tightly controlled protein kinase network, in agreement with its role in atherothrombosis.
Topics: Humans; Agammaglobulinaemia Tyrosine Kinase; Blood Platelets; Phospholipase C gamma; Phosphorylation; Platelet Membrane Glycoproteins; Protein Kinase C; Protein Phosphatase 2; Syk Kinase
PubMed: 37175486
DOI: 10.3390/ijms24097776 -
Micromachines Sep 2022In this investigation, a double immunochromatographic analysis (ICA) of two relevant phycotoxins, domoic acid (DA) and okadaic acid (OA), was developed for the first...
In this investigation, a double immunochromatographic analysis (ICA) of two relevant phycotoxins, domoic acid (DA) and okadaic acid (OA), was developed for the first time. The ICA was performed in the indirect competitive format using gold nanoparticles conjugated with anti-species antibodies. Under optimal conditions, the instrumental detection limits/cutoffs for simultaneous detection of DA and OA were 1.2/100 and 0.1/2.5 ng/mL, respectively. The time of the assay was 18 min. The ICA was applied to test seawater and a large panel of seafood, including mussels, tiger shrimps, octopuses, whelks, crabs, and scallops. The proposed simple sample preparation method for seafood takes only 20 min. For seawater, a dilution by buffer was implemented. The assay recoveries varied from 80.8% to 124.5%. The competitive potential of the proposed technique as a tool to control natural water and seafood samples is determined by its simplicity, rapidity, and sensitivity.
PubMed: 36144129
DOI: 10.3390/mi13091506 -
Advances in Clinical and Experimental... Jun 2020New glucagon-like peptide-1 (GLP-1) analogues developed in recent years have a long half-life and offer further prospects for clinical application. At present, the...
BACKGROUND
New glucagon-like peptide-1 (GLP-1) analogues developed in recent years have a long half-life and offer further prospects for clinical application. At present, the neuroprotection of GLP-1 analogues in Alzheimer's disease (AD) has just begun to be explored.
OBJECTIVES
To investigate how glucagon-like peptide-1 (liraglutide) plays a protective role in AD by regulating tau activation and BACE1 expression.
MATERIAL AND METHODS
Human neuroblastoma cell line SH-SY5Y cells were cultured in vitro and pretreated with different concentrations of liraglutide, and then treated with different concentrations of okadaic acid (OA) in order to observe the apoptosis of the SH-SY5Y cells. After liraglutide treatment, the apoptosis of neurons in AD rats was detected using flow cytometry, and tau activation and β-site APP cleaving enzyme 1 (BACE1) expression were detected using western blot.
RESULTS
Different concentrations of OA were able to induce apoptosis of SH-SY5Y cells in a dose-dependent manner. Different concentrations of liraglutide were used to pretreat SH-SY5Y cells, which were able to protect the SH-SY5Y cells from apoptosis induced by OA. Okadaic acid significantly increased tau activation and BACE1 expression in the SH-SY5Y cells, which was blocked with liraglutide pretreatment. The results of a water maze experiment showed that liraglutide had significant protective effects on memory and cognitive ability in AD rats induced with OA, inhibited apoptosis of neural cells in AD rats, and inhibited tau activation and BACE1 expression of neural cells in AD rats induced with OA.
CONCLUSIONS
Liraglutide has a protective effect on AD in vivo and in vitro, which may be mediated by preventing neuronal apoptosis and inhibiting the activation of tau and the expression of BACE1.
Topics: Alzheimer Disease; Amyloid Precursor Protein Secretases; Animals; Aspartic Acid Endopeptidases; Cell Line, Tumor; Glucagon-Like Peptide 1; Humans; Liraglutide; Neuroprotective Agents; Rats; Receptors, Gastrointestinal Hormone
PubMed: 32614526
DOI: 10.17219/acem/121007 -
Environmental and Ecological Statistics Sep 2022spp. can produce diarrhetic shellfish toxins (DST) including okadaic acid and dinophysistoxins, and some strains can also produce non-diarrheic pectenotoxins. Although...
spp. can produce diarrhetic shellfish toxins (DST) including okadaic acid and dinophysistoxins, and some strains can also produce non-diarrheic pectenotoxins. Although DSTs are of human health concern and have motivated environmental monitoring programs in many locations, these monitoring programs often have temporal data gaps (e.g., days without measurements). This paper presents a model for the historical time-series, on a daily basis, of DST-producing toxigenic in 8 monitored locations in western Andalucía over 2015-2020, incorporating measurements of algae counts and DST levels. We fitted a bivariate hidden Markov Model (HMM) incorporating an autoregressive correlation among the observed DST measurements to account for environmental persistence of DST. We then reconstruct the maximum-likelihood profile of algae presence in the water column at daily intervals using the Viterbi algorithm. Using historical monitoring data from Andalucía, the model estimated that potentially toxigenic algae is present at greater than or equal to 250 cells/L between < 1% and >10% of the year depending on the site and year. The historical time-series reconstruction enabled by this method may facilitate future investigations into temporal dynamics of toxigenic blooms.
PubMed: 36540783
DOI: 10.1007/s10651-022-00534-7 -
Marine Drugs Oct 2022Harmful algal blooms are an increasing worldwide threat to the seafood industry and human health as a consequence of the natural production of biotoxins that can...
Harmful algal blooms are an increasing worldwide threat to the seafood industry and human health as a consequence of the natural production of biotoxins that can accumulate in shellfish. In the Argentine Sea, this has been identified as an issue for the offshore fisheries of Patagonian scallops (), leading to potentially harmful effects on consumers. Here we assess spatial and temporal patterns in marine biotoxin concentrations in Patagonian scallops harvested in Argentinian waters between 2012-2017, based on analyses for paralytic shellfish toxins, lipophilic toxins, and amnesic shellfish toxins. There was no evidence for concentrations of lipophilic or amnesic toxins above regulatory acceptance thresholds, with trace concentrations of pectenotoxin 2, azaspiracid 2 and okadaic acid group toxins confirmed. Conversely, paralytic shellfish toxins were quantified in some scallops. Gonyautoxins 1 and 2 dominated the unusual toxin profiles (91%) in terms of saxitoxin equivalents with maximum concentrations reaching 3985 µg STX eq/kg and with changes in profiles linked in part to seasonal changes. Total toxin concentrations were compared between samples of the adductor muscle and whole tissue, with results showing the absence of toxins in the adductor muscle confirming toxin accumulation in the digestive tracts of the scallops and the absence of a human health threat following the processing of scallop adductor meat. These findings highlight that paralytic shellfish toxins with an unusual toxin profile can occur in relatively high concentrations in whole Patagonian scallops in specific regions and during particular time periods, also showing that the processing of scallops on board factory ships to obtain frozen adductor muscle is an effective management process that minimizes the risk of poisonings from final products destined for human consumption.
Topics: Animals; Humans; Marine Toxins; Okadaic Acid; Saxitoxin; Seafood; Pectinidae
PubMed: 36286458
DOI: 10.3390/md20100634 -
Biomedical and Environmental Sciences :... Jan 2023
Topics: Rats; Animals; Okadaic Acid; PC12 Cells; Triterpenes; tau Proteins; Phosphorylation
PubMed: 36650687
DOI: 10.3967/bes2023.011 -
The Journal of Physiological Sciences :... Jun 2020Tolfenamic acid, a nonsteroidal anti-inflammatory drug, alleviated learning and memory deficits and decreased the expression of specificity protein 1 (SP1)-mediated...
Tolfenamic acid, a nonsteroidal anti-inflammatory drug, alleviated learning and memory deficits and decreased the expression of specificity protein 1 (SP1)-mediated cyclin-dependent kinase-5 (CDK5), a major protein kinase that regulates hyperphosphorylated tau, in Alzheimer's disease (AD) transgenic mice. However, whether tolfenamic acid can regulate the major tau protein kinase, glycogen synthase kinase-3β (GSK-3β), or tau protein phosphatase, protein phosphatase 2A (PP2A), further inhibiting hyperphosphorylation of tau, remains unknown. To this end, tolfenamic acid was administered i.p. in a GSK-3β overactivation postnatal rat model and orally in mice after intracerebroventricular (ICV) injection of okadaic acid (OA) to develop a PP2A inhibition model. We used four behavioural experiments to evaluate memory function in ICV-OA mice. In this study, tolfenamic acid attenuated memory dysfunction. Tolfenamic acid decreased the expression of hyperphosphorylated tau in the brain by inhibiting GSK-3β activity, decreasing phosphorylated PP2A (Tyr307), and enhancing PP2A activity. Tolfenamic acid also increased wortmannin (WT) and GF-109203X (GFX) induced phosphorylation of GSK-3β (Ser9) and prevented OA-induced downregulation of PP2A activity in PC12 cells. Altogether, these results show that tolfenamic acid not only decreased SP1/CDK5-mediated tau phosphorylation, but also inhibited GSK-3β and PP2A-mediated tau hyperphosphorylation in AD models.
Topics: Alzheimer Disease; Animals; Anti-Inflammatory Agents, Non-Steroidal; Disease Models, Animal; Female; Glycogen Synthase Kinase 3 beta; Male; Mice; Mice, Inbred C57BL; Phosphorylation; Protein Phosphatase 2; Rats; Rats, Wistar; ortho-Aminobenzoates; tau Proteins
PubMed: 32517647
DOI: 10.1186/s12576-020-00757-y -
International Journal of Molecular... Feb 2024Three-dimensional (3D) bioprinting is one of the most promising methodologies that are currently in development for the replacement of animal experiments. Bioprinting...
Three-dimensional (3D) bioprinting is one of the most promising methodologies that are currently in development for the replacement of animal experiments. Bioprinting and most alternative technologies rely on animal-derived materials, which compromises the intent of animal welfare and results in the generation of chimeric systems of limited value. The current study therefore presents the first bioprinted liver model that is entirely void of animal-derived constituents. Initially, HuH-7 cells underwent adaptation to a chemically defined medium (CDM). The adapted cells exhibited high survival rates (85-92%) after cryopreservation in chemically defined freezing media, comparable to those preserved in standard medium (86-92%). Xeno-free bioink for 3D bioprinting yielded liver models with high relative cell viability (97-101%), akin to a Matrigel-based liver model (83-102%) after 15 days of culture. The established xeno-free model was used for toxicity testing of a marine biotoxin, okadaic acid (OA). In 2D culture, OA toxicity was virtually identical for cells cultured under standard conditions and in CDM. In the xeno-free bioprinted liver model, 3-fold higher concentrations of OA than in the respective monolayer culture were needed to induce cytotoxicity. In conclusion, this study describes for the first time the development of a xeno-free 3D bioprinted liver model and its applicability for research purposes.
Topics: Animals; Drug-Related Side Effects and Adverse Reactions; Chemical and Drug Induced Liver Injury; Bioprinting; Printing, Three-Dimensional; Tissue Engineering; Tissue Scaffolds
PubMed: 38339088
DOI: 10.3390/ijms25031811 -
Scientific Reports Apr 2024Parkinson's disease (PD) is the second most frequently diagnosed neurodegenerative disease, and it is characterized by the intracellular and extracellular accumulation...
Parkinson's disease (PD) is the second most frequently diagnosed neurodegenerative disease, and it is characterized by the intracellular and extracellular accumulation of α-synuclein (α-syn) and Tau, which are major components of cytosolic protein inclusions called Lewy bodies, in the brain. Currently, there is a lack of effective methods that preventing PD progression. It has been suggested that the plasminogen activation system, which is a major extracellular proteolysis system, is involved in PD pathogenesis. We investigated the functional roles of plasminogen in vitro in an okadaic acid-induced Tau hyperphosphorylation NSC34 cell model, ex vivo using brains from normal controls and methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mice, and in vivo in a widely used MPTP-induced PD mouse model and an α-syn overexpression mouse model. The in vitro, ex vivo and in vivo results showed that the administered plasminogen crossed the blood‒brain barrier (BBB), entered cells, and migrated to the nucleus, increased plasmin activity intracellularly, bound to α-syn through lysine binding sites, significantly promoted α-syn, Tau and TDP-43 clearance intracellularly and even intranuclearly in the brain, decreased dopaminergic neurodegeneration and increased the tyrosine hydroxylase levels in the substantia nigra and striatum, and improved motor function in PD mouse models. These findings indicate that plasminogen plays a wide range of pivotal protective roles in PD and therefore may be a promising drug candidate for PD treatment.
Topics: Animals; Mice; alpha-Synuclein; Disease Models, Animal; DNA-Binding Proteins; Dopamine; Neurodegenerative Diseases; Parkinson Disease; Plasminogen; Serine Proteases; tau Proteins; Dopaminergic Neurons
PubMed: 38615036
DOI: 10.1038/s41598-024-59090-8