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Journal of Biochemical and Molecular... Apr 2024Halomonas pacifica CARE-V15 was isolated from the southeastern coast of India to determine its genome sequence. Secondary metabolite gene clusters were identified using...
Purification, structural characterization, and neuroprotective effect of 3,6-diisobutyl-2,5-piperazinedione from Halomonas pacifica CARE-V15 against okadaic acid-induced neurotoxicity in zebrafish model.
Halomonas pacifica CARE-V15 was isolated from the southeastern coast of India to determine its genome sequence. Secondary metabolite gene clusters were identified using an anti-SMASH server. The concentrated crude ethyl acetate extract was evaluated by GC-MS. The bioactive compound from the crude ethyl acetate extract was fractionated by gel column chromatography. HPLC was used to purify the 3,6-diisobutyl-2,5-piperazinedione (DIP), and the structure was determined using FTIR and NMR spectroscopy. Purified DIP was used in an in silico molecular docking analysis. Purified DIP exhibits a stronger affinity for antioxidant genes like glutathione peroxidase (GPx), glutathione-S-transferase (GST), and glutathione reductase (GSR). Using in silco molecular docking analysis, the protein-ligand binding affinities of GSR (-4.70 kcal/mol), GST (-5.27 kcal/mol), and GPx (-5.37 kcal/mol) were measured. The expression of antioxidant genes were investigated by qRT-PCR. The in vivo reactive oxygen species production, lipid peroxidation, and cell death levels were significantly (p ≤ 0.05) increased in OA-induced group, but all these levels were significantly (p ≤ 0.05) decreased in the purified DIP pretreated group. Purified DIP from halophilic bacteria could thus be a useful treatment for neurological disorders associated with oxidative stress.
Topics: Animals; Antioxidants; Zebrafish; Neuroprotective Agents; Okadaic Acid; Molecular Docking Simulation; Oxidative Stress; Glutathione Peroxidase; Glutathione Reductase; Diketopiperazines; Glutathione Transferase; Acetates; Halomonas
PubMed: 38597299
DOI: 10.1002/jbt.23708 -
Fish & Shellfish Immunology Jun 2024This study was designed to investigate the potential neuronal damage mechanism of the okadaic acid (OA) in the brain tissues of zebrafish embryos by evaluating in terms...
This study was designed to investigate the potential neuronal damage mechanism of the okadaic acid (OA) in the brain tissues of zebrafish embryos by evaluating in terms of immunofluorescence of Nf KB, TLR-4, caspase 3, ERK ½, c-FOS and 8-OHdG signaling pathways. We also evaluated body malformations. For this purpose, zebrafish embryos were exposed to 0.5 μg/ml, 1 μg/ml and 2.5 μg/ml of OA for 5 days. After application, FITC/GFP labeled protein-specific antibodies were used in immunofluorescence assay for NfKB, TLR-4, caspase 3, ERK ½, c-FOS and 8-OHdG respectively. The results indicated that OA caused immunofluorescence positivity of NfKB, TLR-4, caspase 3, ERK ½, c-FOS and 8-OHdG in a dose-dependent manner in the brain tissues of zebrafish embryos. Pericardial edema (PE), nutrient sac edema (YSE) and body malformations, tail malformation, short tail and head malformation (BM) were detected in zebrafish embryos. These results suggest that OA induces neuronal damage by affecting the modulation of DNA damage, apoptotic, and inflammatory activities in the brain tissues of zebrafish embryos. The increase in signaling pathways shows that OA can cause damage in the structure and function of brain nerve cells. Our results provide a new basis for the comprehensive assessment of the neural damage of OA and will offer enable us to better understand molecular the mechanisms underlying the pathophysiology of OA toxicity.
Topics: Animals; Zebrafish; Brain; Toll-Like Receptor 4; Signal Transduction; Okadaic Acid; NF-kappa B; 8-Hydroxy-2'-Deoxyguanosine; Caspase 3; Larva; Proto-Oncogene Proteins c-fos; Deoxyguanosine
PubMed: 38561069
DOI: 10.1016/j.fsi.2024.109529 -
Experimental Cell Research Apr 2024Plasma saturated free fatty acid (FFA)-induced endothelial dysfunction (ED) contributes to the pathogenesis of atherosclerosis and cardiovascular diseases. However, the...
Plasma saturated free fatty acid (FFA)-induced endothelial dysfunction (ED) contributes to the pathogenesis of atherosclerosis and cardiovascular diseases. However, the mechanism underlying saturated FFA-induced ED remains unclear. This study demonstrated that palmitic acid (PA) induced ED by activating the NADPH oxidase (NOX)/ROS signaling pathway to activate protein phosphatase 4 (PP4) and protein phosphatase 2A (PP2A), thereby reducing endothelial nitric oxide synthase (eNOS) phosphorylation at Ser633 and Ser1177, respectively. Okadaic acid (OA) and fostriecin (FST), which are inhibitors of PP2A, inhibited the PA-induced decreases in eNOS phosphorylation at Ser633 and Ser1177. The antioxidants N-acetylcysteine (NAC) and apocynin (APO) or knockdown of gp91phox or p67phox (NOX subunits) restored PA-mediated downregulation of PP4R2 protein expression and eNOS Ser633 phosphorylation. Knockdown of the PP4 catalytic subunit (PP4c) specifically increased eNOS Ser633 phosphorylation, while silencing the PP2A catalytic subunit (PP2Ac) restored only eNOS Ser1177 phosphorylation. Furthermore, PA dramatically decreased the protein expression of the PP4 regulatory subunit R2 (PP4R2) but not the other regulatory subunits. PP4R2 overexpression increased eNOS Ser633 phosphorylation, nitric oxide (NO) production, cell migration and tube formation but did not change eNOS Ser1177 phosphorylation levels. Coimmunoprecipitation (Co-IP) suggested that PP4R2 and PP4c interacted with the PP4R3α and eNOS proteins. In summary, PA decreases PP4R2 protein expression through the Nox/ROS pathway to activate PP4, which contributes to ED by dephosphorylating eNOS at Ser633. The results of this study suggest that PP4 is a novel therapeutic target for ED and ED-associated vascular diseases.
Topics: Humans; Phosphorylation; Nitric Oxide Synthase Type III; Palmitic Acid; Serine; Reactive Oxygen Species; Cells, Cultured; Protein Phosphatase 2; Vascular Diseases; Nitric Oxide; Phosphoprotein Phosphatases
PubMed: 38513962
DOI: 10.1016/j.yexcr.2024.113998 -
Journal of Chromatography. A Apr 2024An accurate and efficient method was developed for the determination of azaspiracid shellfish toxins (azaspiracids-1, -2, and -3), neurotoxic shellfish toxins...
Determination of lipophilic marine biotoxins (azaspiracids, brevetoxins, and okadaic acid group) and domoic acid in mussels by solid-phase extraction and reversed-phase liquid chromatography with tandem mass spectrometry.
An accurate and efficient method was developed for the determination of azaspiracid shellfish toxins (azaspiracids-1, -2, and -3), neurotoxic shellfish toxins (brevetoxins-2 and -3), diarrhetic shellfish toxins (okadaic acid and dinophysistoxins-1 and -2), and the amnesic shellfish toxin (domoic acid) in mussels (Mytilus galloprovincialis). Lipophilic marine biotoxins (azaspiracids, brevetoxins, and okadaic acid group) were extracted with 0.5 % acetic acid in methanol under heating at 60°C to improve the extraction efficiency of okadaic acid group toxins and then cleaned up with a C18 solid-phase extraction cartridge. Domoic acid was extracted with 50 % aqueous methanol and then cleaned up with a graphitized carbon solid-phase extraction cartridge. Lipophilic marine biotoxins and domoic acid were quantified by reversed-phase liquid chromatography coupled to electrospray ionization tandem mass spectrometry. The developed method had insignificant matrix effects for the nine analytes and good recoveries in the range of 79.0 % to 97.6 % at three spiking levels for all analytes except brevetoxin-2 (43.8-49.8 %). The developed method was further validated by analyzing mussel tissue certified reference materials, and good agreement was observed between certified and determined values.
Topics: Animals; Okadaic Acid; Tandem Mass Spectrometry; Chromatography, Reverse-Phase; Methanol; Chromatography, Liquid; Shellfish; Marine Toxins; Bivalvia; Solid Phase Extraction; Polyether Toxins; Kainic Acid; Spiro Compounds; Oxocins
PubMed: 38490144
DOI: 10.1016/j.chroma.2024.464795 -
Current Medicinal Chemistry Mar 2024Traditional Oriental Medicines (TOMs) formulated using a variety of medicinal plants have a low risk of side effects. In previous studies, five TOMs, namely...
BACKGROUND
Traditional Oriental Medicines (TOMs) formulated using a variety of medicinal plants have a low risk of side effects. In previous studies, five TOMs, namely Dangguijakyaksan, Hwanglyeonhaedoktang, Ukgansan, Palmijihwanghwan, and Jowiseungchungtang have been commonly used to treat patients with Alzheimer's disease. However, only a few studies have investigated the effects of these five TOMs on tau pathology.
OBJECTIVE
This study aimed to examine the effect of five TOMs on various tau pathologies, including post-translational modifications, aggregation and deposition, tau-induced neurotoxicity, and tau-induced neuroinflammation.
METHODS
Immunocytochemistry was used to investigate the hyperphosphorylation of tau induced by okadaic acid. In addition, the thioflavin T assay was used to assess the effects of the TOMs on the inhibition of tau K18 aggregation and the dissociation of tau K18 aggregates. Moreover, a water-soluble tetrazolium-1 assay and a quantitative reverse transcription polymerase chain reaction were used to evaluate the effects of the TOMs on tau-induced neurotoxicity and inflammatory cytokines in HT22 and BV2 cells, respectively.
RESULTS
The five TOMs investigated in this study significantly reduced okadaic acid-induced tau hyperphosphorylation. Hwanglyeonhaedoktang inhibited the aggregation of tau and promoted the dissociation of tau aggregates. Dangguijakyaksan and Hwanglyeonhaedoktang attenuated tau-induced neurotoxicity in HT22 cells. In addition, Dangguijakyaksan, Hwanglyeonhaedoktang, Ukgansan, and Palmijihwanghwan reduced tauinduced pro-inflammatory cytokine levels in BV2 cells.
CONCLUSION
Our results suggest that five TOMs are potential therapeutic candidates for tau pathology. In particular, Hwanglyeonhaedoktang showed the greatest efficacy among the five TOMs in cell-free and cell-based screening approaches. These findings suggest that Hwanglyeonhaedoktang is suitable for treating AD patients with tau pathology.
PubMed: 38486385
DOI: 10.2174/0109298673295901240311072440 -
Marine Pollution Bulletin Apr 2024Lipophilic phycotoxins (LPTs) and domoic acid (DA) in Antarctic seawater, as well as parts of the South Pacific and the Southern Indian Oceans were systematically...
Lipophilic phycotoxins (LPTs) and domoic acid (DA) in Antarctic seawater, as well as parts of the South Pacific and the Southern Indian Oceans were systematically investigated. DA and six LPTs, namely pectenotoxin-2 (PTX2), okadaic acid (OA), yessotoxin (YTX), homo-yessotoxin (h-YTX), 13-desmethyl spirolide C (SPX1), and gymnodimine (GYM), were detected. PTX2, as the dominant LPTs, was widely distributed in seawater surrounding Antarctica, whereas OA, YTX, and h-YTX were irregularly distributed across the region. The total concentration of LPTs in surface seawater ranged from 0.10 to 13.57 ng/L (mean = 2.20 ng/L). ∑LPT levels were relatively higher in the eastern sea areas of Antarctica than in the western sea areas. PTX2 was the main LPT in the vertical profiles, and the PTX2 concentration was significantly higher in the epipelagic zone than water depths below 200 m. The predominant sources of PTX2 and OA in Antarctic sea areas are likely to be Dinophysis.
Topics: Marine Toxins; Antarctic Regions; Okadaic Acid; Indian Ocean; Mollusk Venoms; Oxocins
PubMed: 38479322
DOI: 10.1016/j.marpolbul.2024.116250 -
Phytotherapy Research : PTR May 2024Alzheimer's disease (AD) is a neurodegenerative disorder where oxidative stress, induced by ferroptosis, has been linked to neuronal damage and cognitive deficits. The...
Alzheimer's disease (AD) is a neurodegenerative disorder where oxidative stress, induced by ferroptosis, has been linked to neuronal damage and cognitive deficits. The objective of this study is to investigate if the potential therapeutic agent, Curculigoside (CUR), could ameliorate AD by inhibiting ferroptosis. The potential therapeutic targets, such as GPX4 and SLC7A11, were identified using weighted gene co-expression network analysis (WGCNA). Concurrently, CUR was also screened against these potential targets using various analytical methods. For the in vivo studies, intragastric administration of CUR significantly ameliorated cognitive impairment in AD model mice induced by scopolamine and okadaic acid (OA). In vitro, CUR protected neuronal cells by altering the levels of ferroptosis-related specific markers in OA and scopolamine-induced neurotoxicity. The administration of CUR through intragastric route significantly reduced the levels of AD-promoting factors (such as Aβ, p-tau) and ferroptosis-promoting factors in the hippocampus and cortex of AD mice. Furthermore, CUR up-regulated the expression of GPX4 and decreased the expression of SLC7A11 in the ferroptosis signaling pathway, thereby increasing the ratio of glutathione (GSH)/oxidized glutathione (GSSG) in vivo and vitro. In conclusion, the cumulative results suggest that the natural compound CUR may serve as a promising therapeutic agent to ameliorate AD by inhibiting ferroptosis.
Topics: Animals; Alzheimer Disease; Ferroptosis; Oxidative Stress; Mice; Disease Models, Animal; Glucosides; Phospholipid Hydroperoxide Glutathione Peroxidase; Male; Lignans; Amino Acid Transport System y+; Amyloid beta-Peptides; Hippocampus; Medicine, Chinese Traditional; Mice, Inbred C57BL; Drugs, Chinese Herbal; Benzoates
PubMed: 38444049
DOI: 10.1002/ptr.8152 -
International Journal of Biological... Apr 2024Tau is a microtubule-associated protein that plays a critical role in the stabilization and modulation of neuronal axons. Tau pathology is stronger associated with...
Tau is a microtubule-associated protein that plays a critical role in the stabilization and modulation of neuronal axons. Tau pathology is stronger associated with cognitive decline in patients with Alzheimer's disease (AD) than amyloid beta (Aβ) pathology. Hence, tau targeting is a promising approach for the treatment of AD. Previous studies have demonstrated that the non-saponin fraction with rich polysaccharide (NFP) from Korean red ginseng (KRG) can modulate tau aggregation and exert a therapeutic effect on AD. Therefore, we investigated the efficacy of NFP isolated from KRG on tau pathology in experimental models of AD. Our results showed that NFP from KRG ameliorated deposition and hyperphosphorylation of tau in the brain of 3xTg mice. Moreover, NFP from KRG modulated the aggregation and dissociation of tau K18 in vitro. We demonstrated the alleviatory effects of NFP from KRG on hyperphosphorylated tau and tau kinase in okadaic acid-treated HT22 cells. Furthermore, NFP from KRG mitigated Aβ deposition, neurodegeneration, and neuroinflammation in 3xTg mice. We revealed the neuroprotective effects of NFP from KRG on tau-induced neuronal loss in HT22 cells. Our results indicate that NFP extracted from KRG is a novel therapeutic agent for the treatment of AD associated with tau pathology.
Topics: Humans; Mice; Animals; Alzheimer Disease; Amyloid beta-Peptides; tau Proteins; Panax; Mice, Transgenic; Disease Models, Animal
PubMed: 38423419
DOI: 10.1016/j.ijbiomac.2024.130516 -
Archives of Toxicology May 2024Marine biotoxins are a heterogenous group of natural toxins, which are able to trigger different types of toxicological responses in animals and humans. Health effects... (Review)
Review
Marine biotoxins are a heterogenous group of natural toxins, which are able to trigger different types of toxicological responses in animals and humans. Health effects arising from exposure to marine biotoxins are ranging, for example, from gastrointestinal symptoms to neurological effects, depending on the individual toxin(s) ingested. Recent research has shown that the marine biotoxin okadaic acid (OA) can strongly diminish the expression of drug-metabolizing cytochrome P450 (CYP) enzymes in human liver cells by a mechanism involving proinflammatory signaling. By doing so, OA may interfere with the metabolic barrier function of liver and intestine, and thus alter the toxico- or pharmacokinetic properties of other compounds. Such effects of marine biotoxins on drug and xenobiotic metabolism have, however, not been much in the focus of research yet. In this review, we present the current knowledge on the effects of marine biotoxins on CYP enzymes in mammalian cells. In addition, the role of CYP-regulating nuclear receptors as well as inflammatory signaling in the regulation of CYPs by marine biotoxins is discussed. Strong evidence is available for effects of OA on CYP enzymes, along with information about possible molecular mechanisms. For other marine biotoxins, knowledge on effects on drug metabolism, however, is scarce.
Topics: Animals; Humans; Marine Toxins; Cytochrome P-450 Enzyme System; Okadaic Acid; Liver; Receptors, Cytoplasmic and Nuclear; Mammals
PubMed: 38416141
DOI: 10.1007/s00204-024-03694-6 -
Angewandte Chemie (International Ed. in... Apr 2024Pathological hyperphosphorylation and aggregation of microtubule-associated Tau protein contribute to Alzheimer's Disease (AD) and other related tauopathies. Currently,...
Pathological hyperphosphorylation and aggregation of microtubule-associated Tau protein contribute to Alzheimer's Disease (AD) and other related tauopathies. Currently, no cure exists for Alzheimer's Disease. Aptamers offer significant potential as next-generation therapeutics in biotechnology and the treatment of neurological disorders. Traditional aptamer selection methods for Tau protein focus on binding affinity rather than interference with pathological Tau. In this study, we developed a new selection strategy to enrich DNA aptamers that bind to surviving monomeric Tau protein under conditions that would typically promote Tau aggregation. Employing this approach, we identified a set of aptamer candidates. Notably, BW1c demonstrates a high binding affinity (K=6.6 nM) to Tau protein and effectively inhibits arachidonic acid (AA)-induced Tau protein oligomerization and aggregation. Additionally, it inhibits GSK3β-mediated Tau hyperphosphorylation in cell-free systems and okadaic acid-mediated Tau hyperphosphorylation in cellular milieu. Lastly, retro-orbital injection of BW1c tau aptamer shows the ability to cross the blood brain barrier and gain access to neuronal cell body. Through further refinement and development, these Tau aptamers may pave the way for a first-in-class neurotherapeutic to mitigate tauopathy-associated neurodegenerative disorders.
Topics: Humans; Alzheimer Disease; Neurons; Okadaic Acid; Phosphorylation; tau Proteins; Tauopathies; Aptamers, Nucleotide
PubMed: 38407551
DOI: 10.1002/anie.202402007