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  • 1.

    【2hr】Effects of Microcystin-LR on the Microstructure and Inflammation-Related Factors of Jejunum in Mice

    包量

    机译 微囊藻毒素-LR对小鼠空肠微结构和炎症相关因子的影响
    摘要：The increasing cyanobacterial blooms have recently been considered a severe environmental problem. Microcystin-leucine arginine (MC-LR) is one of the secondary products of cyanobacteria metabolism and most harmful cyanotoxins found in water bodies. Studies show MC-LR negatively affects various human organs when exposed to it. The phenotype of the jejunal chronic toxicity induced by MC-LR has not been well described. The aim of this paper was to investigate the effects of MC-LR on the jejunal microstructure and expression level of inflammatory-related factors in jejunum. Mice were treated with different doses (1, 30, 60, 90 and 120 μg/L) of MC-LR for six months. The microstructure and mRNA expression levels of inflammation-related factors in jejunum were analyzed. Results showed that the microstructure of the jejunum was destroyed and expression levels of inflammation-related factors interleukin (IL)-1β, interleukin (IL)-8, tumor necrosis factor alpha, transforming growth factor-β1 and interleukin (IL)-10 were altered at different MC-LR concentrations. To the best of our knowledge, this is the first study that mice were exposed to a high dose of MC-LR for six months. Our data demonstrated MC-LR had the potential to cause intestinal toxicity by destroying the microstructure of the jejunum and inducing an inflammatory response in mice, which provided new insight into understanding the prevention and diagnosis of the intestinal diseases caused by MC-LR.
  • 2.

    【2hr】A Spectroscopic Study on Secondary Structure and Thermal Unfolding of the Plant Toxin Gelonin Confirms Some Typical Structural Characteristics and Unravels the Sequence of Thermal Unfolding Events

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    机译 对植物毒素gelonin的二级结构和热解折叠的光谱研究证实了一些典型的结构特征并揭示了热解折叠事件的顺序
    摘要：Gelonin from the Indian plant Gelonium multiflorum belongs to the type I ribosome-inactivating proteins (RIPs). Like other members of RIPs, this toxin glycoprotein inhibits protein synthesis of eukaryotic cells; hence, it is largely used in the construction of immunotoxins composed of cell-targeted antibodies. Lysosomal degradation is one of the main issues in targeted tumor therapies, especially for type I RIP-based toxins, as they lack the translocation domains. The result is an attenuated cytosolic delivery and a decrease of the antitumor efficacy of these plant-derived toxins; therefore, strategies to permit their release from endosomal vesicles or modifications of the toxins to make them resistant to degradation are necessary to improve their efficacy. Using infrared spectroscopy, we thoroughly analyzed both the secondary structure and the thermal unfolding of gelonin. Moreover, by the combination of two-dimensional correlation spectroscopy and phase diagram method, it was possible to deduce the sequence of events during the unfolding, confirming the typical characteristic of the RIP members to denature in two steps, as a sequential loss of tertiary and secondary structure was detected at 58 °C and at 65 °C, respectively. Additionally, some discrepancies in the unfolding process between gelonin and saporin-S6, another type I RIP protein, were detected.
  • 3.

    【2hr】Evaluation of the Spider (Phlogiellus genus) Phlotoxin 1 and Synthetic Variants as Antinociceptive Drug Candidates

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    机译 蜘蛛（Phlogiellus属）Phlotoxin 1及其合成变体作为抗伤害感受药候选药物的评价
    摘要：Over the two last decades, venom toxins have been explored as alternatives to opioids to treat chronic debilitating pain. At present, approximately 20 potential analgesic toxins, mainly from spider venoms, are known to inhibit with high affinity the NaV1.7 subtype of voltage-gated sodium (NaV) channels, the most promising genetically validated antinociceptive target identified so far. The present study aimed to consolidate the development of phlotoxin 1 (PhlTx1), a 34-amino acid and 3-disulfide bridge peptide of a Phlogiellus genus spider, as an antinociceptive agent by improving its affinity and selectivity for the human (h) NaV1.7 subtype. The synthetic homologue of PhlTx1 was generated and equilibrated between two conformers on reverse-phase liquid chromatography and exhibited potent analgesic effects in a mouse model of NaV1.7-mediated pain. The effects of PhlTx1 and 8 successfully synthetized alanine-substituted variants were studied (by automated whole-cell patch-clamp electrophysiology) on cell lines stably overexpressing hNaV subtypes, as well as two cardiac targets, the hCaV1.2 and hKV11.1 subtypes of voltage-gated calcium (CaV) and potassium (KV) channels, respectively. PhlTx1 and D7A-PhlTx1 were shown to inhibit hNaV1.1–1.3 and 1.5–1.7 subtypes at hundred nanomolar concentrations, while their affinities for hNaV1.4 and 1.8, hCaV1.2 and hKV11.1 subtypes were over micromolar concentrations. Despite similar analgesic effects in the mouse model of NaV1.7-mediated pain and selectivity profiles, the affinity of D7A-PhlTx1 for the NaV1.7 subtype was at least five times higher than that of the wild-type peptide. Computational modelling was performed to deduce the 3D-structure of PhlTx1 and to suggest the amino acids involved in the efficiency of the molecule. In conclusion, the present structure–activity relationship study of PhlTx1 results in a low improved affinity of the molecule for the NaV1.7 subtype, but without any marked change in the molecule selectivity against the other studied ion channel subtypes. Further experiments are therefore necessary before considering the development of PhlTx1 or synthetic variants as antinociceptive drug candidates.
  • 4.

    【2hr】Cytotoxic and Proapoptotic Activity of Sanguinarine, Berberine, and Extracts of Chelidonium majus L. and Berberis thunbergii DC. toward Hematopoietic Cancer Cell Lines

    包量

    机译 血红素，小ber碱以及白屈菜和小Ber DC的提取物的细胞毒性和促凋亡活性。造血癌细胞系
    摘要：Isoquinoline alkaloids belong to the toxic secondary metabolites occurring in plants of many families. The high biological activity makes these compounds promising agents for use in medicine, particularly as anticancer drugs. The aim of our study was to evaluate the cytotoxicity and proapoptotic activity of sanguinarine, berberine, and extracts of Chelidonium majus L. and Berberis thunbergii DC. IC10, IC50, and IC90 doses were established toward hematopoietic cancer cell lines using trypan blue staining. Alterations in the expression of 18 apoptosis-related genes in cells exposed to IC10, IC50, and IC90 were evaluated using real-time PCR. Sanguinarine and Chelidonium majus L. extract exhibit significant cytotoxicity against all studied cell lines. Lower cytotoxic activity was demonstrated for berberine. Berberis thunbergii DC. extract had no influence on cell viability. Berberine, sanguinarine, and Chelidonium majus L. extract altered the expression of apoptosis-related genes in all tested cell lines, indicating the induction of apoptosis. The presented study confirmed the substantial cytotoxicity and proapoptotic activity of sanguinarine, berberine, and Chelidonium majus L. extract toward the studied hematopoietic cell lines, which indicates the utility of these substances in anticancer therapy.
  • 5.

    【2hr】Therapeutic Effects of Botulinum Toxin A, via Urethral Sphincter Injection on Voiding Dysfunction Due to Different Bladder and Urethral Sphincter Dysfunctions

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    机译 尿道括约肌注射肉毒杆菌毒素对不同膀胱和尿道括约肌功能障碍引起的排尿功能障碍的治疗作用
    摘要：Botulinum toxin A (BoNT-A) urethral sphincter injections have been applied in treating voiding dysfunction but the treatment outcome is not consistent. This study analyzed treatment outcomes between patients with different bladder and urethral sphincter dysfunctions. Patients with refractory voiding dysfunction due to neurogenic or non-neurogenic etiology were treated with urethral sphincter 100 U BoNT-A injections. The treatment outcomes were assessed by a global response assessment one month after treatment. The bladder neck opening and urodynamic parameters in preoperative videourodynamic study were compared between successful and failed treatment groups. A total of 80 non-neurogenic and 75 neurogenic patients were included. A successful outcome was noted in 92 (59.4%) patients and a failed outcome in 63 (40.6%). The treatment outcome was not affected by the gender, voiding dysfunction subtype, bladder dysfunction, or sphincter dysfunction subtypes. Except an open bladder neck and higher maximum flow rate, no significant difference was noted in the other variables between groups. Non-neurogenic patients with successful outcomes had a significantly higher detrusor pressure, and patients with neurogenic voiding dysfunction with successful results had higher maximum flow rates and smaller post-void residuals than those who failed the treatment. However, increased urinary incontinence was reported in 12 (13%) patients. BoNT-A urethral sphincter injection is effective in about 60% of either neurogenic or non-neurogenic patients with voiding dysfunction. An open bladder neck during voiding and a higher maximum flow rate indicate a successful treatment outcome.
  • 6.

    【2hr】Accumulation of Microcystin-LR in Grains of Two Rice Varieties (Oryza sativa L.) and a Leafy Vegetable, Ipomoea aquatica

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    机译 两个水稻品种（Oryza sativa L.）和一种多叶蔬菜（Ipomoea aquatica）的谷粒中微囊藻毒素-LR的积累
    摘要：The potential transfer of microcystin-LR (MC-LR) to humans via crop plants irrigated with MC-contaminated water is causing serious concern. In this study, two Oryza sativa variants, a hybrid (BG358), a traditional (Suwandel) variety, and a leafy green vegetable crop, Ipomoea aquatica, were exposed under laboratory conditions to natural blooms of Microcystis aeruginosa sampled from a hypereutrophic lake contaminated with MC-LR (3,197.37 ± 1.04 µg/L). Field samples of O. sativa and I. aquatica were collected from farmlands that had been irrigated from a reservoir, containing MC-LR (180 µg/L). MC-LR was quantified by high performance liquid chromatography followed by photodiode-array detection (HPLC-PDA). From the laboratory study, we calculated the potential human health exposure from BG358, Suwandel and I. aquatica as 2.84 ± 0.01, 0.22 ± 0.01, and 0.06 ± 0.01 µg/kg of body weight/day, respectively, whereas the potential health exposures from BG358, Suwandel and I. aquatica collected from the field were 0.10 ± 0.01, 0.009 ± 0.005, and 0.03 ± 0.01 µg/kg of body weight/day, respectively. In certain instances, the results exceeded the World Health Organization’s (WHO) tolerable daily intake of MC-LR, posing a potential health risk to humans. Thus, our results emphasize the importance of continuous screening programs for cyanotoxins in edible plants in the future to prevent the consumption of contaminated crops.
  • 7.

    【2hr】TMA, A Forgotten Uremic Toxin, but Not TMAO, Is Involved in Cardiovascular Pathology

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    机译 TMA是一种被遗忘的尿毒症毒素，但不是TMAO，涉及心血管病理
    摘要：Trimethylamine-N-oxide (TMAO) has been suggested as a marker and mediator of cardiovascular diseases. However, data are contradictory, and the mechanisms are obscure. Strikingly, the role of the TMAO precursor trimethylamine (TMA) has not drawn attention in cardiovascular studies even though toxic effects of TMA were proposed several decades ago. We assessed plasma TMA and TMAO levels in healthy humans (HH) and cardiovascular patients qualified for aortic valve replacement (CP). The cytotoxicity of TMA and TMAO in rat cardiomyocytes was evaluated using an MTT test. The effects of TMA and TMAO on albumin and lactate dehydrogenase (LDH) were assessed using fluorescence correlation spectroscopy. In comparison to HH, CP had a two-fold higher plasma TMA (p < 0.001) and a trend towards higher plasma TMAO (p = 0.07). In CP plasma, TMA was inversely correlated with an estimated glomerular filtration rate (eGFR, p = 0.002). TMA but not TMAO reduced cardiomyocytes viability. Incubation with TMA but not TMAO resulted in the degradation of the protein structure of LDH and albumin. In conclusion, CP show increased plasma TMA, which is inversely correlated with eGFR. TMA but not TMAO exerts negative effects on cardiomyocytes, likely due to its disturbing effect on proteins. Therefore, TMA but not TMAO may be a toxin and a marker of cardiovascular risk.
  • 8.

    【2hr】Characterization of Phase I and Glucuronide Phase II Metabolites of 17 Mycotoxins Using Liquid Chromatography—High-Resolution Mass Spectrometry

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    机译 液相色谱-高分辨率质谱法表征17种霉菌毒素的I相和葡糖醛酸苷II相代谢产物
    摘要：Routine mycotoxin biomonitoring methods do not include many mycotoxin phase I and phase II metabolites, which may significantly underestimate mycotoxin exposure especially for heavily metabolized mycotoxins. Additional research efforts are also needed to measure metabolites in vivo after exposure and to establish which mycotoxin metabolites should be prioritized for the inclusion during large-scale biomonitoring efforts. The objective of this study was to perform human in vitro microsomal incubations of 17 mycotoxins and systematically characterize all resulting metabolites using liquid chromatography–high-resolution mass spectrometry (LC-HRMS). The results obtained were then used to build a comprehensive LC-MS library and expand a validated 17-mycotoxin method for exposure monitoring to screening of additional 188 metabolites, including 100 metabolites reported for the first time. The final method represents one of the most comprehensive LC-HRMS methods for mycotoxin biomonitoring or metabolism/fate studies.
  • 9.

    【2hr】Gallic Acid Triggers Iron-Dependent Cell Death with Apoptotic, Ferroptotic, and Necroptotic Features

    包量

    机译 没食子酸触发具有凋亡，铁促性和坏死性功能的铁依赖性细胞死亡
    摘要：Gallic acid (GA) is a natural anti-cancer compound that can be found in many food sources, including edible mushrooms, fruits, and vegetables. Studies generally attribute the anti-cancer activity of GA to the induction of apoptosis. Here, we reported that GA activated iron-dependent cell death mechanisms with apoptotic, ferroptotic, and necroptotic features. Our time-lapse live-cell microscopy study demonstrated that GA could induce coexistence of multiple types of cell death pathways, including apoptosis characterized by mitochondrial cytochrome c release and caspase-3 activation, ferroptosis characterized by lipid peroxidation, and necroptosis characterized by the loss of plasma membrane integrity. This GA-induced cell death could be completely suppressed by exposure to an iron chelator deferoxamine, indicating that it is an iron-dependent cell death process. Importantly, MLKL (mixed lineage kinase domain-like protein) inhibitor necrosulfonamide exerted a synergistic effect by increasing the sensitivity of cancer cells to GA. Taken together, our results provide new mechanistic insights, and also suggest new strategies to enhance the efficacy of this natural anti-cancer compound by identifying the agents that can promote or suppress the GA-induced cell death process.
  • 10.

    【2hr】Target Analysis and Retrospective Screening of Multiple Mycotoxins in Pet Food Using UHPLC-Q-Orbitrap HRMS

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    机译 使用UHPLC-Q-Orbitrap HRMS对宠物食品中多种霉菌毒素进行目标分析和回顾性筛选
    摘要：A comprehensive strategy combining a quantitative method for 28 mycotoxins and a post-target screening for other 245 fungal and bacterial metabolites in dry pet food samples were developed using an acetonitrile-based extraction and an ultrahigh-performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS) method. The proposed method showed satisfactory validation results according to Commission Decision 2002/657/EC. Average recoveries from 72 to 108% were obtained for all studied mycotoxins, and the intra-/inter-day precision were below 9 and 14%, respectively. Results showed mycotoxin contamination in 99% of pet food samples (n = 89) at concentrations of up to hundreds µg/kg, with emerging Fusarium mycotoxins being the most commonly detected mycotoxins. All positive samples showed co-occurrence of mycotoxins with the simultaneous presence of up to 16 analytes per sample. In the retrospective screening, up to 54 fungal metabolites were tentatively identified being cyclopiazonic acid, paspalitrem A, fusaric acid, and macrosporin, the most commonly detected analytes.
  • 11.

    【2hr】A Novel Magnetic Molecular Imprinted Polymer for Selective Extraction of Zearalenone from Cereal Flours before Liquid Chromatography-Tandem Mass Spectrometry Determination

    包量

    机译 液相色谱-串联质谱测定前从谷物粉中选择性提取玉米赤霉烯酮的新型磁性分子印迹聚合物
    摘要：Zearalenone (ZEN) is a nonsteroidal estrogenic mycotoxin produced by various Fusarium species and commonly occurring in corn and other cereals. Even though its acute toxicity is low, still the estrogenic activity of ZEN and metabolites is a matter of concern. In this work, a new magnetic molecularly imprinted polymer (mMIP) for the selective extraction of ZEN from cereal flours is presented. The mMIP was synthesized previously using quercetin as dummy template, and here we wanted to test its applicability to complex food samples. Analyte determination was carried out by high-performance liquid chromatography coupled to tandem mass spectrometry. The selectivity of the mMIP and the main validation method parameters were assessed. In particular, even in samples as complex as cereals, matrix effect was negligible. Although the mMIP showed cross-selectivity towards both ZEN-related and quercetin-related compounds, nonetheless ZEN recovery was > 95% for the two lower spiking levels, and the quantification limit was 0.14 ng g−1, i.e., ca. 500 times lower than the maximum limit fixed for most cereals by European law. Therefore, the material, also in comparison with a commercial sorbent, appears suitable for the application in food analysis, also to isolate ZEN at trace levels.
  • 12.

    【2hr】Diversity, Cyanotoxin Production, and Bioactivities of Cyanobacteria Isolated from Freshwaters of Greece

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    机译 从希腊淡水中分离出来的蓝细菌的多样性，氰毒素生产和生物活性
    摘要：Cyanobacteria are a diverse group of photosynthetic Gram-negative bacteria that produce an array of secondary compounds with selective bioactivity against a broad spectrum of organisms and cell lines. In this study, 29 strains isolated from freshwaters in Greece were classified using a polyphasic approach and assigned to Chroococcales, Synechococcales, and Nostocales, representing 11 genera and 17 taxa. There were good agreements between 16S ribosomal RNA (rRNA)–cpcBA–internal genetic spacer (IGS) characterization and morphological features, except for the Jaaginema–Limnothrix group which appears intermixed and needs further elucidation. Methanol extracts of the strains were analyzed for cyanotoxin production and tested against pathogenic bacteria species and several cancer cell lines. We report for the first time a Nostoc oryzae strain isolated from rice fields capable of producing microcystins (MCs) and a Chlorogloeopsis fritschii strain isolated from the plankton of a lake, suggesting that this species may also occur in freshwater temperate habitats. Strains with very high or identical 16S rRNA gene sequences displayed different antibacterial and cytotoxic activities. Extracts from Synechococcus cf. nidulans showed the most potent antibacterial activity against Staphylococcus aureus, whereas Jaaginema sp. strains exhibited potent cytotoxic activities against human colorectal adenocarcinoma and hepatocellular carcinoma cells. Jaaginema Thessaloniki Aristotle University Microalgae and Cyanobacteria (TAU-MAC) 0110 and 0210 strains caused pronounced changes in the actin network and triggered the formation of numerous lipid droplets in hepatocellular carcinoma and green monkey kidney cells, suggesting oxidative stress and/or mitochondrial damage leading to apoptosis.
  • 13.

    【2hr】Influence of Two Garlic-Derived Compounds, Propyl Propane Thiosulfonate (PTS) and Propyl Propane Thiosulfinate (PTSO), on Growth and Mycotoxin Production by Fusarium Species In Vitro and in Stored Cereals

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    机译 两种大蒜衍生的化合物硫丙烷丙丙烷（PTS）和丙硫丙烷丙酸酯（PTSO）对镰刀菌种体外和贮藏谷物的生长和霉菌毒素产生的影响
    摘要：Two garlic-derived compounds, Propyl Propane Thiosulfonate (PTS) and Propyl Propane Thiosulfinate (PTSO), were examined for their efficacy against mycotoxigenic Fusarium species (F. graminearum, F. langsethiae, F. verticillioides). The objectives were to assess the inhibitory effect of these compounds on growth and mycotoxin production in vitro, and in situ in artificially inoculated wheat, oats and maize with one isolate of each respectively, at different water activity (aw) conditions when stored for up to 20 days at 25 °C. In vitro, 200 ppm of either PTS or PTSO reduced fungal growth by 50–100% and mycotoxin production by >90% depending on species, mycotoxin and aw conditions on milled wheat, oats and maize respectively. PTS was generally more effective than PTSO. Deoxynivalenol (DON) and zearalenone (ZEN) were decreased by 50% with 80 ppm PTSO. One-hundred ppm of PTS reduced DON and ZEN production in wheat stored at 0.93 aw for 20 days, although contamination was still above the legislative limits. Contrasting effects on T-2/HT-2 toxin contamination of oats was found depending on aw, with PTS stimulating production under marginal conditions (0.93 aw), but at 0.95 aw effective control was achieved with 100 ppm. Treatment of stored maize inoculated with F. verticilliodies resulted in a stimulation of total fumonsins in most treatments. The potential use of such compounds for mycotoxin control in stored commodities is discussed.
  • 14.

    【2hr】Effects of Antagonists on Mycotoxins of Seedborne Fusarium spp. in Sweet Corn

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    机译 拮抗剂对种子传播的镰刀菌属真菌毒素的影响。在甜玉米
    摘要：Fusarium species coexist as toxigenic, systemic pathogens in sweet corn seed production in southwestern Idaho, USA. We hypothesized that fungal antagonists of seedborne Fusarium would differentially alter production of Fusarium mycotoxins directly and/or systemically. We challenged the Fusarium complex by in vitro antagonism trials and in situ silk and seed inoculations with fungal antagonists. Fungal antagonists reduced growth and sporulation of Fusarium species in vitro from 40.5% to as much as 100%. Pichia membranifaciens and Penicillium griseolum reduced fumonisin production by F. verticillioides by 73% and 49%, respectively, while P. membranifaciens and a novel Penicillium sp. (WPT) reduced fumonisins by F. proliferatum 56% and 78%, respectively. In situ, pre-planting inoculation of seeds with Penicillium WPT systemically increased fumonisins in the resulting crop. Morchella snyderi applied to silks of an F1 cross systemically reduced deoxynivalenol by 47% in mature seeds of the F2. Antagonists failed to suppress Fusarium in mature kernels following silk inoculations, although the ratio of F. verticillioides to total Fusarium double with some inoculants. Fusarium mycotoxin concentrations in sweet corn seed change systemically, as well as locally, in response to the presence of fungal antagonists, although in Fusarium presence in situ was not changed.
  • 15.

    【2hr】Venomic, Transcriptomic, and Bioactivity Analyses of Pamphobeteus verdolaga Venom Reveal Complex Disulfide-Rich Peptides That Modulate Calcium Channels

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    机译 Vermphaga Pamphobeteus verdolaga毒液的系统动力学，转录组学和生物活性分析揭示了调节钙离子通道的富含二硫键的复杂肽。
    摘要：Pamphobeteus verdolaga is a recently described Theraphosidae spider from the Andean region of Colombia. Previous reports partially characterized its venom profile. In this study, we conducted a detailed analysis that includes reversed-phase high-performance liquid chromatography (rp-HPLC), calcium influx assays, tandem mass spectrometry analysis (tMS/MS), and venom-gland transcriptome. rp-HPLC fractions of P. verdolaga venom showed activity on CaV2.2, CaV3.2, and NaV1.7 ion channels. Active fractions contained several peptides with molecular masses ranging from 3399.4 to 3839.6 Da. The tMS/MS analysis of active fraction displaying the strongest activity to inhibit calcium channels showed sequence fragments similar to one of the translated transcripts detected in the venom-gland transcriptome. The putative peptide of this translated transcript corresponded to a toxin, here named ω-theraphositoxin-Pv3a, a potential ion channel modulator toxin that is, in addition, very similar to other theraphositoxins affecting calcium channels (i.e., ω-theraphotoxin-Asp1a). Additionally, using this holistic approach, we found that P. verdolaga venom is an important source of disulfide-rich proteins expressing at least eight superfamilies.
  • 16.

    【2hr】Ergochromes: Heretofore Neglected Side of Ergot Toxicity

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    机译 Ergochromes：迄今为止被忽略的麦角毒副作用
    摘要：Ergot, fungal genus Claviceps, are worldwide distributed grass pathogens known for their production of toxic ergot alkaloids (EAs) and the great agricultural impact they have on both cereal crop and farm animal production. EAs are traditionally considered as the only factor responsible for ergot toxicity. Using broad sampling covering 13 ergot species infecting wild or agricultural grasses (including cereals) across Europe, USA, New Zealand, and South Africa we showed that the content of ergochrome pigments were comparable to the content of EAs in sclerotia. While secalonic acids A–C (SAs), the main ergot ergochromes (ECs), are well known toxins, our study is the first to address the question about their contribution to overall ergot toxicity. Based on our and published data, the importance of SAs in acute intoxication seems to be negligible, but the effect of chronic exposure needs to be evaluated. Nevertheless, they have biological activities at doses corresponding to quantities found in natural conditions. Our study highlights the need for a re-evaluation of ergot toxicity mechanisms and further studies of SAs’ impact on livestock production and food safety.
  • 17.

    【2hr】Synthesis and Characterization of Cry2Ab–AVM Bioconjugate: Enhanced Affinity to Binding Proteins and Insecticidal Activity

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    机译 Cry2Ab-AVM生物共轭物的合成和表征：增强对结合蛋白的亲和力和杀虫活性
    摘要：Bacillus thuringiensis insecticidal proteins (Bt toxins) have been widely used in crops for agricultural pest management and to reduce the use of chemical insecticides. Here, we have engineered Bt toxin Cry2Ab30 and bioconjugated it with 4”-O-succinyl avermectin (AVM) to synthesize Cry2Ab–AVM bioconjugate. It was found that Cry2Ab–AVM showed higher insecticidal activity against Plutella xylostella, up to 154.4 times compared to Cry2Ab30. The binding results showed that Cry2Ab–AVM binds to the cadherin-like binding protein fragments, the 10th and 11th cadherin repeat domains in the P. xylostella cadherin (PxCR10–11), with a much higher affinity (dissociation equilibrium constant KD = 3.44 nM) than Cry2Ab30 (KD = 28.7 nM). Molecular docking suggested that the macrolide lactone group of Cry2Ab–AVM ligand docking into the PxCR10–11 is a potential mechanism to enhance the binding affinity of Cry2Ab–AVM to PxCR10–11. These findings offer scope for the engineering of Bt toxins by bioconjugation for improved pest management.
  • 18.

    【2hr】Bacillus thuringiensis Vip1 Functions as a Receptor of Vip2 Toxin for Binary Insecticidal Activity against Holotrichia parallela

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    机译 苏云金芽孢杆菌Vip1充当Vip2毒素的受体，具有对平行线虫病的二元杀虫活性。
    摘要：Bacillus thuringiensis is a well-known entomopathogenic bacterium that produces vegetative insecticidal proteins (Vips, including Vip1, Vip2, Vip3, and Vip4) during the vegetative phase. Here, we purified Vip1 and Vip2 from B. thuringiensis and characterized the insecticidal effects of these protoxins. Bioassay results showed that a 1:1 mixture of Vip1Ad and Vip2Ag, purified by ion-affinity chromatography independently, exhibited insecticidal activity against Holotrichia parallela larvae, with a 50% lethal concentration value of 2.33 μg/g soil. The brush border membrane (BBM) in the midgut of H. parallela larvae was destroyed after feeding the Vip1Ad and Vip2Ag mixture. Vacuolization of the cytoplasm and slight destruction of BBM were detected with Vip2Ag alone, but not with Vip1Ad alone. Notably, Vip1Ad bound to BBM vesicles (BBMVs) strongly, whereas Vip2Ag showed weak binding; however, binding of Vip2Ag to BBMV was increased when Vip1Ad was added. Ligand blotting showed that Vip2Ag did not bind to Vip1Ad but bound to Vip1Ad-t (Vip1Ad was activated by trypsin), suggesting the activation of Vip1Ad was important for their binary toxicity. Thus, our findings suggested that Vip1Ad may facilitate the binding of Vip2Ag to BBMVs, providing a basis for studies of the insecticidal mechanisms of Vip1Ad and Vip2Ag.
  • 19.

    【2hr】Insights into the Diversity of Secondary Metabolites of Planktothrix Using a Biphasic Approach Combining Global Genomics and Metabolomics

    包量

    机译 利用全球基因组学和代谢组学相结合的双相方法洞察浮游生物次级代谢产物的多样性
    摘要：Cyanobacteria are an ancient lineage of slow-growing photosynthetic bacteria and a prolific source of natural products with diverse chemical structures and potent biological activities and toxicities. The chemical identification of these compounds remains a major bottleneck. Strategies that can prioritize the most prolific strains and novel compounds are of great interest. Here, we combine chemical analysis and genomics to investigate the chemodiversity of secondary metabolites based on their pattern of distribution within some cyanobacteria. Planktothrix being a cyanobacterial genus known to form blooms worldwide and to produce a broad spectrum of toxins and other bioactive compounds, we applied this combined approach on four closely related strains of Planktothrix. The chemical diversity of the metabolites produced by the four strains was evaluated using an untargeted metabolomics strategy with high-resolution LC–MS. Metabolite profiles were correlated with the potential of metabolite production identified by genomics for the different strains. Although, the Planktothrix strains present a global similarity in terms of a biosynthetic cluster gene for microcystin, aeruginosin, and prenylagaramide for example, we found remarkable strain-specific chemodiversity. Only few of the chemical features were common to the four studied strains. Additionally, the MS/MS data were analyzed using Global Natural Products Social Molecular Networking (GNPS) to identify molecular families of the same biosynthetic origin. In conclusion, we depict an efficient, integrative strategy for elucidating the chemical diversity of a given genus and link the data obtained from analytical chemistry to biosynthetic genes of cyanobacteria.
  • 20.

    【2hr】Determination of Deoxynivalenol Biomarkers in Italian Urine Samples

    包量

    机译 意大利尿液样品中脱氧雪腐烯醇生物标志物的测定
    摘要：Deoxynivalenol (DON) is a mycotoxin mainly produced by Fusarium graminearum that can contaminate cereals and cereal-based foodstuff. Urinary DON levels can be used as biomarker for exposure assessment purposes. This study assessed urinary DON concentrations in Italian volunteers recruited by age group, namely children, adolescents, adults, and the elderly. In addition, vulnerable groups, namely vegetarians and pregnant women, were included in the study. To determine the urinary DON, its glucuronide and de-epoxydated (DOM-1) forms, an indirect analytical approach was used, measuring free DON and total DON (as sum of free and glucuronides forms), before and after enzymatic treatment, respectively. Morning urine samples were collected on two consecutive days, from six different population groups, namely children, adolescent, adults, elderly, vegetarians and pregnant women. Total DON was measured in the 76% of the collected samples with the maximum incidences in children and adolescent age group. Urine samples from children and adolescent also showed the highest total DON levels, up to 17.0 ng/mgcreat. Pregnant women had the lowest positive samples per category (40% for day 1 and 43% for day 2, respectively), low mean levels of total DON (down to 2.84 ng/mgcreat) and median equal to 0 ng/mgcreat. Estimation of DON dietary intake reveals that 7.5% of the total population exceeds the TDI of 1 μg/kg bw/day set for DON, with children showing 40% of individuals surpassing this value (male, day 2).
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