1
|
Neale DA, Morris JC, Verrills NM, Ammit AJ. Understanding the regulatory landscape of protein phosphatase 2A (PP2A): Pharmacological modulators and potential therapeutics. Pharmacol Ther 2025; 269:108834. [PMID: 40023321 DOI: 10.1016/j.pharmthera.2025.108834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2024] [Revised: 01/20/2025] [Accepted: 02/20/2025] [Indexed: 03/04/2025]
Abstract
Protein phosphatase 2A (PP2A) is a ubiquitously expressed serine/threonine phosphatase with a diverse and integral role in cellular signalling pathways. Consequently, its dysfunction is frequently observed in disease states such as cancer, inflammation and Alzheimer's disease. A growing understanding of both PP2A and its endogenous regulatory proteins has presented numerous targets for therapeutic intervention. This provides important context for the dynamic control and dysregulation of PP2A function in disease states. Understanding the intricate regulation of PP2A signalling in disease has resulted in the development of novel pharmacological agents aimed at restoring cellular homeostasis. Herein we review the structure and function of PP2A together with pharmacological modulators, both endogenous (proteins) and exogenous (small molecules and peptides), with relevance to targeting PP2A as a future pharmacotherapeutic strategy.
Collapse
Affiliation(s)
- David A Neale
- School of Chemistry, UNSW Sydney, NSW 2052, Australia
| | | | - Nicole M Verrills
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, University of Newcastle, NSW 2308, Australia; Precision Medicine Program, Hunter Medical Research Institute, New Lambton, NSW 2305, Australia
| | - Alaina J Ammit
- Woolcock Emphysema Centre, Woolcock Institute of Medical Research, Macquarie University, NSW, Australia; School of Life Sciences, Faculty of Science, University of Technology Sydney, NSW, Australia.
| |
Collapse
|
2
|
Jaeger-Honz S, Hackett R, Fotler R, Dietrich DR, Schreiber F. Conformation and binding of 12 Microcystin (MC) congeners to PPP1 using molecular dynamics simulations: A potential approach in support of an improved MC risk assessment. Chem Biol Interact 2025; 407:111372. [PMID: 39788475 DOI: 10.1016/j.cbi.2025.111372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2024] [Revised: 12/20/2024] [Accepted: 12/21/2024] [Indexed: 01/12/2025]
Abstract
Microcystins (MCs) occur frequently during cyanobacterial blooms worldwide, representing a group of currently about 300 known MC congeners, which are structurally highly similar. Human exposure to MCs via contaminated water, food or dietary supplements can lead to severe intoxications with ensuing high morbidity and in some cases mortality. Currently, one MC congener (MC-LR) is almost exclusively considered for risk assessment (RA) by the WHO. Many MC congeners co-occur during bloom events, of which MC-LR is not the most toxic. Indeed, MC congeners differ dramatically in their inherent toxicity, consequently raising question about the reliability of the WHO RA and the derived guidance values. Molecular dynamics (MD) simulation can aid in understanding differences in toxicity, as experimental validation for all known MC congeners is not feasible. Therefore, we present MD simulations of a total of twelve MC congeners, of which eight MC congeners were simulated for the first time. We show that depending on their structure and toxicity class, MCs adapt to different backbone conformations. These backbone conformations are specific to certain MC congeners and can change or shift to other conformations upon binding to PPP1, affecting the stability of the binding. Analysis of the interactions with PPP1 demonstrated that there are frequently occurring patterns for individual MC congeners, and that published PPP interactions could be reproduced. In addition, common but also unique patterns were found for individual MC congeners, suggesting differences in binding behaviour. The MD simulations presented here therefore enhance our understanding of MC congener-specific differences and demonstrated that congener-specific investigations are prerequisite for allowing characterisation of yet untested or even unknown MC congeners, thereby allowing for a novel potential approach in support of an improved RA of microcystins in humans.
Collapse
Affiliation(s)
- Sabrina Jaeger-Honz
- Department of Informatics and Information Science, University of Konstanz, Germany
| | - Raymund Hackett
- Department of Informatics and Information Science, University of Konstanz, Germany
| | - Regina Fotler
- Department of Biology, University of Konstanz, Germany
| | | | - Falk Schreiber
- Department of Informatics and Information Science, University of Konstanz, Germany; Faculty of Information Technology, Monash University, Australia.
| |
Collapse
|
3
|
Sallandt L, Wolf CA, Schuster S, Enke H, Enke D, Wolber G, Niedermeyer THJ. Derivatization of Microcystins Can Increase Target Inhibition while Reducing Cellular Uptake. JOURNAL OF NATURAL PRODUCTS 2025; 88:3-14. [PMID: 39427253 PMCID: PMC11773564 DOI: 10.1021/acs.jnatprod.4c00688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2024] [Revised: 09/30/2024] [Accepted: 09/30/2024] [Indexed: 10/21/2024]
Abstract
Microcystins, a large family of nonribosomal cyclic heptapeptides known for their hepatotoxicity, are among the best-studied cyanobacterial toxins. Recently, they have been discussed as leads for the development of anticancer drug substances. Their main mode-of-action is inhibition of the eukaryotic serine/threonine protein phosphatases 1 and 2A. Unlike many cytotoxins that can cross cell membranes by passive diffusion, microcystins depend on active uptake via organic anion transporting polypeptides 1B1 or 1B3. Both phosphatase inhibition and transportability strongly depend on the structure of the individual microcystin. Here, we present how chemical modification of positions 2 and 4 of the microcystin core structure can alter these two properties. Aiming to reduce transportability and increase phosphatase inhibition, we used pharmacophore modeling to investigate the phosphatase inhibition potential of microcystins derivatized with small molecules containing a variety of functional groups. The respective derivatives were synthesized using click chemistry. We discovered that some derivatized microcystins can address a yet undescribed subpocket of the protein phosphatase 1. The derivatized microcystins were tested for phosphatase 1 inhibition and cytotoxicity on transporter-expressing cell lines, revealing that target inhibition and transportability of microcystins can independently be influenced by the physicochemical properties, especially of the residue located in position 2 of the microcystin. Derivatization with small acids or amino acids resulted in microcystins with a favorable ratio of inhibition to transportability, making these derivatives potentially suitable for drug development.
Collapse
Affiliation(s)
- Laura
L. Sallandt
- Department
of Pharmaceutical Biology, Institute of Pharmacy, Freie Universität Berlin, 14195 Berlin, Germany
| | - Clemens A. Wolf
- Department
of Pharmaceutical Chemistry (Molecular Drug Design), Institute of
Pharmacy, Freie Universität Berlin, 14195 Berlin, Germany
| | | | - Heike Enke
- Simris
Biologics GmbH, 12489 Berlin, Germany
| | - Dan Enke
- Simris
Biologics GmbH, 12489 Berlin, Germany
| | - Gerhard Wolber
- Department
of Pharmaceutical Chemistry (Molecular Drug Design), Institute of
Pharmacy, Freie Universität Berlin, 14195 Berlin, Germany
| | - Timo H. J. Niedermeyer
- Department
of Pharmaceutical Biology, Institute of Pharmacy, Freie Universität Berlin, 14195 Berlin, Germany
| |
Collapse
|
4
|
Hassanein F, Fadel HH, Shehata AI, Hamdy NA, Masoud IM. In silico study to explore the mechanism of Toxoplasma-induced inflammation and target therapy based on sero and salivary Toxoplasma. Sci Rep 2024; 14:13600. [PMID: 38866852 PMCID: PMC11169245 DOI: 10.1038/s41598-024-63735-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Accepted: 05/31/2024] [Indexed: 06/14/2024] Open
Abstract
We aimed to assess salivary and seroprevalence of Toxoplasma immunoglobulins in risky populations and evaluate drug docking targeting TgERP. A cross-sectional study was conducted in Alexandria University hospitals' outpatient clinics. 192 participants were enrolled from September 2022 to November 2023. Anti-Toxoplasma IgG and IgM were determined in serum and saliva by ELISA. An in-Silico study examined TgERP's protein-protein interactions (PPIs) with pro-inflammatory cytokine receptors, anti-inflammatory cytokine, cell cycle progression regulatory proteins, a proliferation marker, and nuclear envelope integrity-related protein Lamin B1. Our findings revealed that anti-T. gondii IgG were detected in serum (66.1%) and saliva (54.7%), with 2.1% of both samples were positive for IgM. Salivary IgG had 75.59% sensitivity, 86.15% specificity, 91.40% PPV, 64.40% NPP, 79.17% accuracy and fair agreement with serum IgG. On the other hand, the sensitivity, specificity, PPV, NPV, and accuracy in detecting salivary IgM were 75.0%, 99.47%, 75.0%, 99.47%, and 98.96%. AUC 0.859 indicates good discriminatory power. Examined synthetic drugs and natural products can target specific amino acids residues of TgERP that lie at the same binding interface with LB1 and Ki67, subsequently, hindering their interaction. Hence, salivary samples can be a promising diagnostic approach. The studied drugs can counteract the pro-inflammatory action of TgERP.
Collapse
Affiliation(s)
- Faika Hassanein
- Department of Microbiology & Immunology, Faculty of Dentistry, Pharos University in Alexandria, Alexandria, Egypt.
| | - Hewida H Fadel
- Department of Medical Laboratory Technology, Faculty of Applied Health Sciences Technology, Pharos University in Alexandria, Alexandria, Egypt
| | - Amany I Shehata
- Department of Tropical Health, High Institute of Public Health, Alexandria University, Alexandria, Egypt
| | - Noha Alaa Hamdy
- Department of Clinical Pharmacy & Pharmacy Practice, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt
| | - Inas M Masoud
- Department of Pharmacology and Therapeutics, Faculty of Pharmacy, Pharos University in Alexandria, Alexandria, Egypt
| |
Collapse
|
5
|
Riehle E, Beach DG, Multrus S, Parmar TP, Martin-Creuzburg D, Dietrich DR. Fate of Planktothrix-derived toxins in aquatic food webs: A case study in Lake Mindelsee (Germany). ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 273:116154. [PMID: 38422789 DOI: 10.1016/j.ecoenv.2024.116154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 02/19/2024] [Accepted: 02/23/2024] [Indexed: 03/02/2024]
Abstract
Blooms of the red, filamentous cyanobacterium Planktothrix rubescens occur frequently in pre-alpine lakes in Europe, often with concomitant toxic microcystin (MC) production. Trophic transfer of MCs has been observed in bivalves, fish, and zooplankton species, while uptake of MCs into Diptera species could facilitate distribution of MCs into terrestrial food webs and habitats. In this study, we characterized a Planktothrix bloom in summer 2019 in Lake Mindelsee and tracked possible trophic transfer and/or bioaccumulation of MCs via analysis of phytoplankton, zooplankton (Daphnia) and emergent aquatic insects (Chaoborus, Chironomidae and Trichoptera). Using 16 S rRNA gene amplicon sequencing, we found that five sequence variants of Planktothrix spp. were responsible for bloom formation in September and October of 2019, and these MC-producing variants, provisionally identified as P. isothrix and/or P. serta, occurred exclusively in Lake Mindelsee (Germany), while other variants were also detected in nearby Lake Constance. The remaining cyanobacterial community was dominated by Cyanobiaceae species with high species overlap with Lake Constance, suggesting a well-established exchange of cyanobacteria species between the adjacent lakes. With targeted LC-HRMS/MS we identified two MC-congeners, MC-LR and [Asp3]MC-RR with maximum concentrations of 45 ng [Asp3]MC-RR/L in lake water in September. Both MC congeners displayed different predominance patterns, suggesting that two different MC-producing species occurred in a time-dependent manner, whereby [Asp3]MC-RR was clearly associated with the Planktothrix spp. bloom. We demonstrate an exclusive transfer of MC-LR, but not [Asp3]MC-RR, from phytoplankton into zooplankton reaching a 10-fold bioconcentration, yet complete absence of these MC congeners or their conjugates in aquatic insects. The latter demonstrated a limited trophic transfer of MCs from zooplankton to zooplanktivorous insect larvae (e.g., Chaoborus), or direct transfer into other aquatic insects (e.g. Chironomidae and Trichoptera), whether due to avoidance or limited uptake and/or rapid excretion of MCs by higher trophic emergent aquatic insects.
Collapse
Affiliation(s)
- Eva Riehle
- University of Konstanz, Human and Environmental Toxicology Research Group, Universitaetsstrasse 10, Konstanz 78464, Germany.
| | - Daniel G Beach
- National Research Council Canada, Biotoxin Metrology, 1411 Oxford St., Halifax, Nova Scotia B3H 3Z1, Canada
| | - Selina Multrus
- University of Konstanz, Human and Environmental Toxicology Research Group, Universitaetsstrasse 10, Konstanz 78464, Germany
| | - Tarn Preet Parmar
- Brandenburg Technical University (BTU), Cottbus-Senftenberg, Department of Aquatic Ecology, Seestrasse 45, Bad Saarow 15526, Germany
| | - Dominik Martin-Creuzburg
- Brandenburg Technical University (BTU), Cottbus-Senftenberg, Department of Aquatic Ecology, Seestrasse 45, Bad Saarow 15526, Germany
| | - Daniel R Dietrich
- University of Konstanz, Human and Environmental Toxicology Research Group, Universitaetsstrasse 10, Konstanz 78464, Germany.
| |
Collapse
|
6
|
Alba-Posse EJ, Bruque CD, Gándola Y, Gasulla J, Nadra AD. From in-silico screening to in-vitro evaluation: Enhancing the detection of Microcystins with engineered PP1 mutant variants. J Struct Biol 2023; 215:108043. [PMID: 37935286 DOI: 10.1016/j.jsb.2023.108043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Revised: 10/20/2023] [Accepted: 11/04/2023] [Indexed: 11/09/2023]
Abstract
Cyanotoxins produced during harmful algal blooms (CyanoHABs) have become a worldwide issue of concern. Microcystins (MC) are the most ubiquitous group of cyanotoxins and have known carcinogenic and hepatotoxic effects. The protein phosphatase inhibition assays (PPIAs), based on the inhibition of Protein Phosphatase 1/2A (PP1/PP2A) by MC, are one of the most cost-effective options for detecting MC. In this work, we aimed to design in-silico and evaluate in-vitro mutant variants of the PP1 protein, in order to enhance their capabilities as a MC biosensor. To this end, we performed an in-silico active site-saturated mutagenesis screening, followed by stability and docking affinity calculation with the MCLR cyanotoxin. Candidates with improved both affinity and stability were further tested in a fully flexible active-site docking. The best-scored mutations (19) were individually analysed regarding their locations and interactions. Four of them (p.D197F; p.Q249Y; p.S129W; p.D220Q) were selected for in-vitro expression and evaluation. Mutant p.D197F, exhibited a significant increment in inhibition by MCLR with respect to the WT, while showing a non-significant difference in stability nor activity. This successful PP1 inhibition enhancement suggests the potential of the p.D197F variant for practical MC detection applications.
Collapse
Affiliation(s)
- Ezequiel J Alba-Posse
- Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología y Biología Molecular y Celular, Instituto de Biociencias, Biotecnología y Biología Traslacional (iB3), Universidad de Buenos Aires, Intendente Güiraldes 2160, C1428EGA Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Godoy Cruz 2290, C1425FQB Buenos Aires, Argentina
| | - Carlos David Bruque
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Godoy Cruz 2290, C1425FQB Buenos Aires, Argentina; Unidad de Conocimiento Traslacional Hospitalaria Patagónica, Hospital de Alta Complejidad El Calafate - S.A.M.I.C., Jorge Newbery 453, CP9405 El Calafate, Santa Cruz, Argentina
| | - Yamila Gándola
- Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología y Biología Molecular y Celular, Instituto de Biociencias, Biotecnología y Biología Traslacional (iB3), Universidad de Buenos Aires, Intendente Güiraldes 2160, C1428EGA Buenos Aires, Argentina
| | - Javier Gasulla
- Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología y Biología Molecular y Celular, Instituto de Biociencias, Biotecnología y Biología Traslacional (iB3), Universidad de Buenos Aires, Intendente Güiraldes 2160, C1428EGA Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Godoy Cruz 2290, C1425FQB Buenos Aires, Argentina.
| | - Alejandro D Nadra
- Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología y Biología Molecular y Celular, Instituto de Biociencias, Biotecnología y Biología Traslacional (iB3), Universidad de Buenos Aires, Intendente Güiraldes 2160, C1428EGA Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Godoy Cruz 2290, C1425FQB Buenos Aires, Argentina.
| |
Collapse
|
7
|
Ye X, Zhang P, Tao J, Wang JCK, Mafi A, Grob NM, Quartararo AJ, Baddock HT, Chan LJG, McAllister FE, Foe I, Loas A, Eaton DL, Hao Q, Nile AH, Pentelute BL. Discovery of reactive peptide inhibitors of human papillomavirus oncoprotein E6. Chem Sci 2023; 14:12484-12497. [PMID: 38020382 PMCID: PMC10646941 DOI: 10.1039/d3sc02782a] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 08/22/2023] [Indexed: 12/01/2023] Open
Abstract
Human papillomavirus (HPV) infections account for nearly all cervical cancer cases, which is the fourth most common cancer in women worldwide. High-risk variants, including HPV16, drive tumorigenesis in part by promoting the degradation of the tumor suppressor p53. This degradation is mediated by the HPV early protein 6 (E6), which recruits the E3 ubiquitin ligase E6AP and redirects its activity towards ubiquitinating p53. Targeting the protein interaction interface between HPV E6 and E6AP is a promising modality to mitigate HPV-mediated degradation of p53. In this study, we designed a covalent peptide inhibitor, termed reactide, that mimics the E6AP LXXLL binding motif by selectively targeting cysteine 58 in HPV16 E6 with quantitative conversion. This reactide provides a starting point in the development of covalent peptidomimetic inhibitors for intervention against HPV-driven cancers.
Collapse
Affiliation(s)
- Xiyun Ye
- Department of Chemistry, Massachusetts Institute of Technology 77 Massachusetts Avenue Cambridge MA 02139 USA
| | - Peiyuan Zhang
- Department of Chemistry, Massachusetts Institute of Technology 77 Massachusetts Avenue Cambridge MA 02139 USA
| | - Jason Tao
- Department of Chemistry, Massachusetts Institute of Technology 77 Massachusetts Avenue Cambridge MA 02139 USA
| | - John C K Wang
- Calico Life Sciences LLC 1170 Veterans Boulevard South San Francisco CA 94080 USA
| | - Amirhossein Mafi
- Calico Life Sciences LLC 1170 Veterans Boulevard South San Francisco CA 94080 USA
| | - Nathalie M Grob
- Department of Chemistry, Massachusetts Institute of Technology 77 Massachusetts Avenue Cambridge MA 02139 USA
| | - Anthony J Quartararo
- Department of Chemistry, Massachusetts Institute of Technology 77 Massachusetts Avenue Cambridge MA 02139 USA
| | - Hannah T Baddock
- Calico Life Sciences LLC 1170 Veterans Boulevard South San Francisco CA 94080 USA
| | - Leanne J G Chan
- Calico Life Sciences LLC 1170 Veterans Boulevard South San Francisco CA 94080 USA
| | - Fiona E McAllister
- Calico Life Sciences LLC 1170 Veterans Boulevard South San Francisco CA 94080 USA
| | - Ian Foe
- Calico Life Sciences LLC 1170 Veterans Boulevard South San Francisco CA 94080 USA
| | - Andrei Loas
- Department of Chemistry, Massachusetts Institute of Technology 77 Massachusetts Avenue Cambridge MA 02139 USA
| | - Dan L Eaton
- Calico Life Sciences LLC 1170 Veterans Boulevard South San Francisco CA 94080 USA
| | - Qi Hao
- Calico Life Sciences LLC 1170 Veterans Boulevard South San Francisco CA 94080 USA
| | - Aaron H Nile
- Calico Life Sciences LLC 1170 Veterans Boulevard South San Francisco CA 94080 USA
| | - Bradley L Pentelute
- Department of Chemistry, Massachusetts Institute of Technology 77 Massachusetts Avenue Cambridge MA 02139 USA
- The Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology 500 Main Street Cambridge MA 02142 USA
- Center for Environmental Health Sciences, Massachusetts Institute of Technology 77 Massachusetts Avenue Cambridge MA 02139 USA
- Broad Institute of MIT and Harvard 415 Main Street Cambridge MA 02142 USA
| |
Collapse
|
8
|
Stark GF, Martin RM, Smith LE, Wei B, Hellweger FL, Bullerjahn GS, McKay RML, Boyer GL, Wilhelm SW. Microcystin aids in cold temperature acclimation: Differences between a toxic Microcystis wildtype and non-toxic mutant. HARMFUL ALGAE 2023; 129:102531. [PMID: 37951605 PMCID: PMC10640677 DOI: 10.1016/j.hal.2023.102531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 10/20/2023] [Accepted: 10/20/2023] [Indexed: 11/14/2023]
Abstract
For Microcystis aeruginosa PCC 7806, temperature decreases from 26 °C to 19 °C double the microcystin quota per cell during growth in continuous culture. Here we tested whether this increase in microcystin provided M. aeruginosa PCC 7806 with a fitness advantage during colder-temperature growth by comparing cell concentration, cellular physiology, reactive oxygen species damage, and the transcriptomics-inferred metabolism to a non-toxigenic mutant strain M. aeruginosa PCC 7806 ΔmcyB. Photo-physiological data combined with transcriptomic data revealed metabolic changes in the mutant strain during growth at 19 °C, which included increased electron sinks and non-photochemical quenching. Increased gene expression was observed for a glutathione-dependent peroxiredoxin during cold treatment, suggesting compensatory mechanisms to defend against reactive oxygen species are employed in the absence of microcystin in the mutant. Our observations highlight the potential selective advantages of a longer-term defensive strategy in management of oxidative stress (i.e., making microcystin) vs the shorter-term proactive strategy of producing cellular components to actively dissipate or degrade oxidative stress agents.
Collapse
Affiliation(s)
- Gwendolyn F Stark
- Department of Microbiology, The University of Tennessee, Knoxville, TN, USA
| | - Robbie M Martin
- Department of Microbiology, The University of Tennessee, Knoxville, TN, USA
| | - Laura E Smith
- Department of Microbiology, The University of Tennessee, Knoxville, TN, USA
| | - Bofan Wei
- Department of Chemistry, State University of New York College of Environmental Science and Forestry, Syracuse, NY, USA
| | - Ferdi L Hellweger
- Water Quality Engineering, Technical University of Berlin, Berlin, Germany
| | - George S Bullerjahn
- Department of Biological Sciences, Bowling Green State University, Bowling Green, OH, USA
| | - R Michael L McKay
- Great Lakes Institute for Environmental Research, The University of Windsor, Windsor, ON, Canada
| | - Gregory L Boyer
- Department of Chemistry, State University of New York College of Environmental Science and Forestry, Syracuse, NY, USA
| | - Steven W Wilhelm
- Department of Microbiology, The University of Tennessee, Knoxville, TN, USA.
| |
Collapse
|
9
|
Beach DG, Zamlynny L, MacArthur M, Miles CO. Liquid chromatography-high-resolution tandem mass spectrometry of anatoxins, including new conjugates and reduction products. Anal Bioanal Chem 2023; 415:5281-5296. [PMID: 37507466 PMCID: PMC10444699 DOI: 10.1007/s00216-023-04836-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 06/27/2023] [Accepted: 06/30/2023] [Indexed: 07/30/2023]
Abstract
Anatoxins (ATXs) are a potent class of cyanobacterial neurotoxins for which only a handful of structural analogues have been well characterized. Here, we report the development of an LC-HRMS/MS method for the comprehensive detection of ATXs. Application of this method to samples of benthic cyanobacterial mats and laboratory cultures showed detection of several new ATXs. Many of these result from nucleophilic addition to the olefinic bond of the α,β-unsaturated ketone functional group of anatoxin-a (ATX) and homoanatoxin-a (hATX), analogous to the conjugation chemistry of microcystins, which contain similar α,β-unsaturated amide functionality. Conjugates with glutathione, γ-glutamylcysteine, methanethiol, ammonia, methanol and water were detected, as well as putative C-10 alcohol derivatives. Structural confirmation was obtained by simple and selective analytical-scale semisynthetic reactions starting from available ATX standards. Methanol, water and ammonia conjugates were found to result primarily from sample preparation. Reduction products were found to result from enzymatic reactions occurring primarily after cell lysis in laboratory cultures of Kamptonema formosum and Cuspidothrix issatschenkoi. The relative contributions of the identified analogues to the anatoxin profiles in a set of 22 benthic-cyanobacterial-mat field samples were estimated, showing conjugates to account for up to 15% of total ATX peak area and 10-hydroxyanatoxins up to 38%. The developed methodology, new analogues and insight into the chemical and enzymatic reactivity of ATXs will enable a more comprehensive study of the class than possible previously.
Collapse
Affiliation(s)
- Daniel G Beach
- Biotoxin Metrology, National Research Council Canada, 1411 Oxford St., Halifax, NS, Canada.
| | - Lydia Zamlynny
- Biotoxin Metrology, National Research Council Canada, 1411 Oxford St., Halifax, NS, Canada
| | - Melanie MacArthur
- Biotoxin Metrology, National Research Council Canada, 1411 Oxford St., Halifax, NS, Canada
| | - Christopher O Miles
- Biotoxin Metrology, National Research Council Canada, 1411 Oxford St., Halifax, NS, Canada
| |
Collapse
|
10
|
Stark GF, Martin RM, Smith LE, Wei B, Hellweger FL, Bullerjahn GS, McKay RML, Boyer GL, Wilhelm SW. Cool temperature acclimation in toxigenic Microcystis aeruginosa PCC 7806 and its non-toxigenic mutant. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.28.555099. [PMID: 37693631 PMCID: PMC10491114 DOI: 10.1101/2023.08.28.555099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
For Microcystis aeruginosa PCC 7806, temperature decreases from 26° C to 19° C double the microcystin quota per cell during growth in continuous culture. Here we tested whether this increase in microcystin provided M. aeruginosa PCC 7806 with a fitness advantage during colder-temperature growth by comparing cell concentration, cellular physiology, and the transcriptomics-inferred metabolism to a non-toxigenic mutant strain M. aeruginosa PCC 7806 ΔmcyB. Photo-physiological data combined with transcriptomic data revealed metabolic changes in the mutant strain during growth at 19° C, which included increased electron sinks and non-photochemical quenching. Increased gene expression was observed for a glutathione-dependent peroxiredoxin during cold treatment, suggesting compensatory mechanisms to defend against reactive oxygen species are employed in the absence of microcystin in the mutant. Our observations highlight the potential selective advantages of a longer-term defensive strategy in management of oxidative stress (i.e., making microcystin) vs the shorter-term proactive strategy of producing cellular components to actively dissipate or degrade oxidative stress agents.
Collapse
Affiliation(s)
- Gwendolyn F Stark
- Department of Microbiology, The University of Tennessee, Knoxville, TN, USA
| | - Robbie M Martin
- Department of Microbiology, The University of Tennessee, Knoxville, TN, USA
| | - Laura E Smith
- Department of Microbiology, The University of Tennessee, Knoxville, TN, USA
| | - Bofan Wei
- Department of Chemistry, State University of New York College of Environmental Science and Forestry, Syracuse, NY, USA
| | - Ferdi L Hellweger
- Water Quality Engineering, Technical University of Berlin, Berlin, Germany
| | - George S Bullerjahn
- Department of Biological Sciences, Bowling Green State University, Bowling Green, OH, USA
| | - R Michael L McKay
- Great Lakes Institute for Environmental Research, The University of Windsor, Windsor, ON, Canada
| | - Gregory L Boyer
- Department of Chemistry, State University of New York College of Environmental Science and Forestry, Syracuse, NY, USA
| | - Steven W Wilhelm
- Department of Microbiology, The University of Tennessee, Knoxville, TN, USA
| |
Collapse
|
11
|
Microcystin-LR, a Cyanobacterial Toxin, Induces Changes in the Organization of Membrane Compartments in Arabidopsis. Microorganisms 2023; 11:microorganisms11030586. [PMID: 36985160 PMCID: PMC10051171 DOI: 10.3390/microorganisms11030586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 02/20/2023] [Accepted: 02/22/2023] [Indexed: 03/02/2023] Open
Abstract
To evaluate the effects of the cyanobacterial toxin microcystin-LR (MCY-LR, a protein phosphatase inhibitor) and diquat (DQ, an oxidative stress inducer) on the organization of tonoplast, the effect of MCY-LR on plastid stromule formation and on mitochondria was investigated in wild-type Arabidopsis. Tonoplast was also studied in PP2A catalytic (c3c4) and regulatory subunit mutants (fass-5 and fass-15). These novel studies were performed by CLSM microscopy. MCY-LR is produced during cyanobacterial blooms. The organization of tonoplast of PP2A mutants of Arabidopsis is much more sensitive to MCY-LR and DQ treatments than that of wild type. In c3c4, fass-5 and fass-15, control and treated plants showed increased vacuole fragmentation that was the strongest when the fass-5 mutant was treated with MCY-LR. It is assumed that both PP2A/C and B” subunits play an important role in normal formation and function of the tonoplast. In wild-type plants, MCY-LR affects mitochondria. Under the influence of MCY-LR, small, round-shaped mitochondria appeared, while long/fused mitochondria were typical in control plants. Presumably, MCY-LR either inhibits the fusion of mitochondria or induces fission. Consequently, PP2A also plays an important role in the fusion of mitochondria. MCY-LR also increased the frequency of stromules appearing on chloroplasts after 1 h treatments. Along the stromules, signals can be transported between plastids and endoplasmic reticulum. It is probable that they promote a faster response to stress.
Collapse
|
12
|
Turner AD, Beach DG, Foss A, Samdal IA, Løvberg KLE, Waack J, Edwards C, Lawton LA, Dean KJ, Maskrey BH, Lewis AM. A Feasibility Study into the Production of a Mussel Matrix Reference Material for the Cyanobacterial Toxins Microcystins and Nodularins. Toxins (Basel) 2022; 15:27. [PMID: 36668847 PMCID: PMC9867187 DOI: 10.3390/toxins15010027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 12/15/2022] [Accepted: 12/23/2022] [Indexed: 01/03/2023] Open
Abstract
Microcystins and nodularins, produced naturally by certain species of cyanobacteria, have been found to accumulate in aquatic foodstuffs such as fish and shellfish, resulting in a risk to the health of the seafood consumer. Monitoring of toxins in such organisms for risk management purposes requires the availability of certified matrix reference materials to aid method development, validation and routine quality assurance. This study consequently targeted the preparation of a mussel tissue reference material incurred with a range of microcystin analogues and nodularins. Nine targeted analogues were incorporated into the material as confirmed through liquid chromatography with tandem mass spectrometry (LC-MS/MS), with an additional 15 analogues detected using LC coupled to non-targeted high resolution mass spectrometry (LC-HRMS). Toxins in the reference material and additional source tissues were quantified using LC-MS/MS, two different enzyme-linked immunosorbent assay (ELISA) methods and with an oxidative-cleavage method quantifying 3-methoxy-2-methyl-4-phenylbutyric acid (MMPB). Correlations between the concentrations quantified using the different methods were variable, likely relating to differences in assay cross-reactivities and differences in the abilities of each method to detect bound toxins. A consensus concentration of total soluble toxins determined from the four independent test methods was 2425 ± 575 µg/kg wet weight. A mean 43 ± 9% of bound toxins were present in addition to the freely extractable soluble form (57 ± 9%). The reference material produced was homogenous and stable when stored in the freezer for six months without any post-production stabilization applied. Consequently, a cyanotoxin shellfish reference material has been produced which demonstrates the feasibility of developing certified seafood matrix reference materials for a large range of cyanotoxins and could provide a valuable future resource for cyanotoxin risk monitoring, management and mitigation.
Collapse
Affiliation(s)
- Andrew D. Turner
- Centre for Environment Fisheries and Aquaculture Science, Barrack Road, Weymouth DT4 8UB, UK
| | - Daniel G. Beach
- Biotoxin Metrology, National Research Council Canada, Halifax, NS B3H 3Z1, Canada
| | - Amanda Foss
- Greenwater Laboratories, 205 Zeagler Drive, Suite 302, Palatka, FL 32177, USA
| | | | | | - Julia Waack
- Centre for Environment Fisheries and Aquaculture Science, Barrack Road, Weymouth DT4 8UB, UK
- CyanoSol, School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen AB10 7GJ, UK
| | - Christine Edwards
- CyanoSol, School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen AB10 7GJ, UK
| | - Linda A. Lawton
- CyanoSol, School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen AB10 7GJ, UK
| | - Karl J. Dean
- Centre for Environment Fisheries and Aquaculture Science, Barrack Road, Weymouth DT4 8UB, UK
| | - Benjamin H. Maskrey
- Centre for Environment Fisheries and Aquaculture Science, Barrack Road, Weymouth DT4 8UB, UK
| | - Adam M. Lewis
- Centre for Environment Fisheries and Aquaculture Science, Barrack Road, Weymouth DT4 8UB, UK
| |
Collapse
|
13
|
Paulson JR, Vander Mause ER, Dillinger E, Luedeman ME, Usman B. Ellman's reagent prevents dephosphorylation of histones during isolation of mitotic chromosomes. Chromosome Res 2022; 30:351-359. [PMID: 36399199 DOI: 10.1007/s10577-022-09709-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 10/21/2022] [Accepted: 10/27/2022] [Indexed: 11/19/2022]
Abstract
Histones H1 and H3 are highly phosphorylated in mitotic HeLa cells but are rapidly dephosphorylated by endogenous protein phosphatases during the isolation of metaphase chromosomes. We show that this dephosphorylation can be prevented by including the sulfhydryl reagent 5,5'-dithiobis-(2-nitrobenzoate) (Ellman's reagent, or DTNB) in the isolation buffer. The minimal amount of DTNB required is approximately stoichiometric with the number of sulfhydryl groups in the lysate. Inhibition of the protein phosphatases can subsequently be reversed by treatment with dithiothreitol or 2-mercaptoethanol. DTNB is compatible with the isolation of either metaphase chromosome clusters or individual metaphase chromosomes. It should be useful in investigations of the structure and biochemistry of chromatin and chromosomes and in the study of possible functions for mitotic histone phosphorylation.
Collapse
Affiliation(s)
- James R Paulson
- Department of Chemistry, University of Wisconsin Oshkosh, Oshkosh, WI, 54901, USA.
| | - Erica R Vander Mause
- Department of Chemistry, University of Wisconsin Oshkosh, Oshkosh, WI, 54901, USA
- , A2 Biotherapeutics, Agoura Hills, CA, 91301, USA
| | - Elizabeth Dillinger
- Department of Chemistry, University of Wisconsin Oshkosh, Oshkosh, WI, 54901, USA
- Division of Nephrology and Hypertension, Mayo Clinic College of Medicine and Science, 200 First Street SW, Rochester, MN, 55905, USA
| | - Megan E Luedeman
- Department of Chemistry, University of Wisconsin Oshkosh, Oshkosh, WI, 54901, USA
- 32-038 Lineberger Comprehensive Cancer Center, 450 West Drive, Chapel Hill, NC, 27599, USA
| | - Bakhtawar Usman
- Department of Chemistry, University of Wisconsin Oshkosh, Oshkosh, WI, 54901, USA
- Clarity Clinic-Lakeview, 3665 N. Broadway, Chicago, IL, 60613, USA
| |
Collapse
|
14
|
Painefilú JC, González C, Cárcamo JG, Bianchi VA, Luquet CM. Microcystin-LR modulates multixenobiotic resistance proteins in the middle intestine of rainbow trout, Oncorhynchus mykiss. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2022; 253:106327. [PMID: 36274501 DOI: 10.1016/j.aquatox.2022.106327] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 09/23/2022] [Accepted: 10/13/2022] [Indexed: 06/16/2023]
Abstract
Global climate change favors explosive population growth events (blooms) of phytoplanktonic species, often producing toxic products, e.g., several genera of cyanobacteria synthesize a family of cyanotoxins called microcystins (MCs). Freshwater fish such as the rainbow trout Oncorhynchus mykiss can uptake MCs accumulated in the food chain. We studied the toxic effects and modulation of the activity and expression of multixenobiotic resistance proteins (ABCC transporters and the enzyme glutathione S-transferase (GST) in the O. mykiss middle intestine by microcystin-LR (MCLR). Juvenile fish were fed with MCLR incorporated in the food every 12 h and euthanized at 12, 24, or 48 h. We estimated the ABCC-mediated transport in ex vivo intestinal strips to estimate ABCC-mediated transport activity. We measured total and reduced (GSH) glutathione contents and GST and glutathione reductase (GR) activities. We studied MCLR cytotoxicity by measuring protein phosphatase 1 (PP1) activity and lysosomal membrane stability. Finally, we examined the relationship between ROS production and lysosomal membrane stability through in vitro experiments. Dietary MCLR had a time-dependent effect on ABCC-mediated transport, from inhibition at 12 h to a significant increase after 48 h. GST activity decreased only at 12 h, and GR activity only increased at 48 h. There were no effects on GSH or total glutathione contents. MCLR inhibited PP1 activity and diminished the lysosomal membrane stability at the three experimental times. In the in vitro study, the lysosomal membrane stability decreased in a concentration-dependent fashion from 0 to 5 µmol L - 1 MCLR, while ROS production increased only at 5 µmol L - 1 MCLR. MCLR did not affect mRNA expression of abcc2 or gst-π. We conclude that MCLR modulates ABCC-mediated transport activity in O. mykiss's middle intestine in a time-dependent manner. The transport rate increase does not impair MCLR cytotoxic effects.
Collapse
Affiliation(s)
- Julio C Painefilú
- Laboratorio de Ictiología y Acuicultura Experimental, IPATEC (CONICET-UNCo). Quintral 1250. San Carlos de Bariloche, 8400, Río Negro, Argentina
| | - Carolina González
- Agua y Saneamientos Argentinos, Tucumán 752, 1049 Buenos Aires, Argentina; Laboratorio de Limnología, Facultad de Ciencias Exactas y Naturales, UBA, Argentina
| | - Juan G Cárcamo
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Campus Isla Teja, Valdivia, Chile; Centro FONDAP, Interdisciplinary Center for Aquaculture Research (INCAR), Chile
| | - Virginia A Bianchi
- Laboratorio de Ecotoxicología Acuática, Subsede INIBIOMA-CEAN (CONICET-UNCo). Ruta provincial 61, km 3, Junín de los Andes, 8371 Neuquén, Argentina
| | - Carlos M Luquet
- Laboratorio de Ecotoxicología Acuática, Subsede INIBIOMA-CEAN (CONICET-UNCo). Ruta provincial 61, km 3, Junín de los Andes, 8371 Neuquén, Argentina.
| |
Collapse
|
15
|
Cunningham BR, Wharton RE, Lee C, Mojica MA, Krajewski LC, Gordon SC, Schaefer AM, Johnson RC, Hamelin EI. Measurement of Microcystin Activity in Human Plasma Using Immunocapture and Protein Phosphatase Inhibition Assay. Toxins (Basel) 2022; 14:toxins14110813. [PMID: 36422987 PMCID: PMC9697287 DOI: 10.3390/toxins14110813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 11/10/2022] [Accepted: 11/18/2022] [Indexed: 11/23/2022] Open
Abstract
Microcystins are toxic chemicals generated by certain freshwater cyanobacteria. These chemicals can accumulate to dangerous levels during harmful algal blooms. When exposed to microcystins, humans are at risk of hepatic injury, including liver failure. Here, we describe a method to detect microcystins in human plasma by using immunocapture followed by a protein phosphatase inhibition assay. At least 279 microcystins have been identified, and most of these compounds share a common amino acid, the Adda side chain. We targeted this Adda side chain using a commercial antibody and extracted microcystins from human samples for screening and analysis. To quantitate the extracted microcystins, we fortified plasma with microcystin-LR, one of the most well-studied, commonly detected, and toxic microcystin congeners. The quantitation range for the detection of microcystin in human plasma using this method is 0.030-0.50 ng/mL microcystin-LR equivalents. This method detects unconjugated and conjugated forms (cysteine and glutathione) of microcystins. Quality control sample accuracies varied between 98.9% and 114%, with a precision of 7.18-15.8%. Finally, we evaluated plasma samples from a community health surveillance project of Florida residents living or working near harmful algae blooms.
Collapse
Affiliation(s)
- Brady R. Cunningham
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA
| | - Rebekah E. Wharton
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA
| | - Christine Lee
- Division of Foodborne, Waterborne, and Environmental Diseases, National Center Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA
| | - Mike A. Mojica
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA
| | - Logan C. Krajewski
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA
| | - Shirley C. Gordon
- Christine E. Lynn College of Nursing, Florida Atlantic University, Boca Raton, FL 33431, USA
| | | | - Rudolph C. Johnson
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA
| | - Elizabeth I. Hamelin
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA
- Correspondence:
| |
Collapse
|
16
|
Patteson JB, Fortinez CM, Putz AT, Rodriguez-Rivas J, Bryant LH, Adhikari K, Weigt M, Schmeing TM, Li B. Structure and Function of a Dehydrating Condensation Domain in Nonribosomal Peptide Biosynthesis. J Am Chem Soc 2022; 144:14057-14070. [PMID: 35895935 DOI: 10.1021/jacs.1c13404] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Dehydroamino acids are important structural motifs and biosynthetic intermediates for natural products. Many bioactive natural products of nonribosomal origin contain dehydroamino acids; however, the biosynthesis of dehydroamino acids in most nonribosomal peptides is not well understood. Here, we provide biochemical and bioinformatic evidence in support of the role of a unique class of condensation domains in dehydration (CmodAA). We also obtain the crystal structure of a CmodAA domain, which is part of the nonribosomal peptide synthetase AmbE in the biosynthesis of the antibiotic methoxyvinylglycine. Biochemical analysis reveals that AmbE-CmodAA modifies a peptide substrate that is attached to the donor carrier protein. Mutational studies of AmbE-CmodAA identify several key residues for activity, including four residues that are mostly conserved in the CmodAA subfamily. Alanine mutation of these conserved residues either significantly increases or decreases AmbE activity. AmbE exhibits a dimeric conformation, which is uncommon and could enable transfer of an intermediate between different protomers. Our discovery highlights a central dehydrating function for CmodAA domains that unifies dehydroamino acid biosynthesis in diverse nonribosomal peptide pathways. Our work also begins to shed light on the mechanism of CmodAA domains. Understanding CmodAA domain function may facilitate identification of new natural products that contain dehydroamino acids and enable engineering of dehydroamino acids into nonribosomal peptides.
Collapse
Affiliation(s)
- Jon B Patteson
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Camille Marie Fortinez
- Department of Biochemistry and Centre de recherche en biologie structurale, McGill University, Montréal, Canada H3G 0B1
| | - Andrew T Putz
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Juan Rodriguez-Rivas
- Sorbonne Université, CNRS, Institut de Biologie Paris Seine, Biologie Computationnelle et Quantitative - LCQB, Paris 75005, France
| | - L Henry Bryant
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Kamal Adhikari
- Department of Biochemistry and Centre de recherche en biologie structurale, McGill University, Montréal, Canada H3G 0B1
| | - Martin Weigt
- Sorbonne Université, CNRS, Institut de Biologie Paris Seine, Biologie Computationnelle et Quantitative - LCQB, Paris 75005, France
| | - T Martin Schmeing
- Department of Biochemistry and Centre de recherche en biologie structurale, McGill University, Montréal, Canada H3G 0B1
| | - Bo Li
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| |
Collapse
|
17
|
Baliu-Rodriguez D, Peraino NJ, Premathilaka SH, Birbeck JA, Baliu-Rodriguez T, Westrick JA, Isailovic D. Identification of Novel Microcystins Using High-Resolution MS and MS n with Python Code. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:1652-1663. [PMID: 35018784 DOI: 10.1021/acs.est.1c04296] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Cyanotoxins called microcystins (MCs) are highly toxic and can be present in drinking water sources. Determining the structure of MCs is paramount because of its effect on toxicity. Though over 300 MC congeners have been discovered, many remain unidentified. Herein, a method is described for the putative identification of MCs using liquid chromatography (LC) coupled with high-resolution (HR) Orbitrap mass spectrometry (MS) and a new bottom-up sequencing strategy. Maumee River water samples were collected during a harmful algal bloom and analyzed by LC-MS with simultaneous HRMS and MS/MS. Unidentified ions with characteristic MC fragments (135 and 213 m/z) were recognized as possible novel MC congeners. An innovative workflow was developed for the putative identification of these ions. Python code was written to generate the potential structures of unidentified MCs and to assign ions after the fragmentation for structural confirmation. The workflow enabled the putative identification of eight previously reported MCs for which standards are not available and two newly discovered congeners, MC-HarR and MC-E(OMe)R.
Collapse
Affiliation(s)
- David Baliu-Rodriguez
- Department of Chemistry and Biochemistry, University of Toledo, Toledo, Ohio 43606, United States
| | - Nicholas J Peraino
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, United States
| | - Sanduni H Premathilaka
- Department of Chemistry and Biochemistry, University of Toledo, Toledo, Ohio 43606, United States
| | - Johnna A Birbeck
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, United States
| | | | - Judy A Westrick
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, United States
| | - Dragan Isailovic
- Department of Chemistry and Biochemistry, University of Toledo, Toledo, Ohio 43606, United States
| |
Collapse
|
18
|
Jaeger-Honz S, Nitschke J, Altaner S, Klein K, Dietrich DR, Schreiber F. Investigation of microcystin conformation and binding towards PPP1 by molecular dynamics simulation. Chem Biol Interact 2022; 351:109766. [PMID: 34861245 DOI: 10.1016/j.cbi.2021.109766] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 11/18/2021] [Accepted: 11/19/2021] [Indexed: 11/30/2022]
Abstract
Microcystins (MC) are a group of structurally similar cyanotoxins with currently 279 described structural variants. Human exposure is frequent by consumption of contaminated water, food or food supplements. MC can result in serious intoxications, commensurate with ensuing pathology in various organs or in rare cases even mortality. The current WHO risk assessment primarily considers MC-LR, while all other structural variants are treated as equivalent to MC-LR, despite that current data strongly suggest that MC-LR is not the most toxic MC, and toxicity can be very different for MC congeners. To investigate and analyse binding and conformation of different MC congeners, we applied for the first time Molecular Dynamics (MD) simulation to four MC congeners (MC-LR, MC-LF, [Enantio-Adda5]MC-LF, [β-D-Asp3,Dhb7]MC-RR). We could show that ser/thr protein phosphatase 1 is stable in all MD simulations and that MC-LR backbone adopts to a second conformation in solvent MD simulation, which was previously unknown. We could also show that MC congeners can adopt to different backbone conformation when simulated in solvent or in complex with ser/thr protein phosphatase 1 and differ in their binding behaviour. Our findings suggest that MD Simulation of different MC congeners aid in understanding structural differences and binding of this group of structurally similar cyanotoxins.
Collapse
Affiliation(s)
- Sabrina Jaeger-Honz
- Department of Computer and Information Science, University of Konstanz, Germany
| | - Jahn Nitschke
- Department of Biology, University of Konstanz, Germany
| | | | - Karsten Klein
- Department of Computer and Information Science, University of Konstanz, Germany
| | | | - Falk Schreiber
- Department of Computer and Information Science, University of Konstanz, Germany; Faculty of Information Technology, Monash University, Australia.
| |
Collapse
|
19
|
Koto Y, Kawahara H, Kurata K, Yoshikiyo K, Hashiguchi A, Okano K, Sugiura N, Shimizu K, Shimizu H. Microcystin-LR incorporated into colonic cells through probenecid-sensitive transporters leads to upregulated MCP-1 expression induced by JNK activation. Toxicol Rep 2022; 9:937-944. [PMID: 35875256 PMCID: PMC9301606 DOI: 10.1016/j.toxrep.2022.04.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 04/16/2022] [Accepted: 04/18/2022] [Indexed: 11/29/2022] Open
Abstract
Harmful algae that inhabit eutrophic lakes produce cyanotoxic microcystins. Therefore, the relationship between chronic exposure to microcystins via drinking water and organ disorders has been investigated. The present study aimed to determine whether representative microcystin-LR is involved in increased monocyte chemoattractant protein-1 (MCP-1) expression in rat colonic mucosa and enterocyte-like differentiated Caco-2 cells. The mRNA expression of MCP-1 was increased in the colons of rats administered with microcystin-LR, compared with controls. Furthermore, mRNA levels of MCP-1 expression significantly and positively correlated with those of Adhesion G Protein-Coupled Receptor E1 (ADGRE1; EMR1; F4/80), an indicator of macrophage infiltration, suggesting that increased MCP-1 expression induced by microcystin-LR promotes macrophage infiltration into the colon. Microcystin-LR increased MCP-1 expression in enterocyte-like differentiated Caco-2 cells, by activating c-Jun N-terminal kinase (JNK), but not extracellular signal-regulated kinase (ERK) or p38. The findings of transporter inhibitors indicated that microcystin-LR is incorporated into cells via ATP Binding Cassette (ABC) or solute carrier (SLC) transporters other than the organic anion transporting polypeptides (OATPs)1B1, 1B3, 2B1, and 1A2, which this leads to increased MCP-1 expression in the colon through activating JNK. Thus, increased MCP-1 expression induced by microcystin-LR might be a trigger for initiating tumorigenesis with inflammation in the colon because increased MCP-1 expression induces inflammation associated with macrophage infiltration into the colon, and chronic inflammation is associated with the initiation of tumorigenesis. Microcystin-LR upregulated colonic MCP-1 expression in rats. Increased MCP-1 expression correlated with accumulated macrophages in rat colon. Microcystin-LR evoked MCP-1 expression by activating JNK in cultured colon cells. Rifampicin was not involved in microcystin-LR-induced JNK activation. Probenecid suppressed JNK/MCP-1 pathway activation induced by microcystin-LR.
Collapse
Affiliation(s)
- Yoshihito Koto
- Graduate School of Natural Science and Technology, Shimane University, 1060 Nishikawatsu-Cho, Matsue, Shimane 690-8504, Japan
| | - Hideaki Kawahara
- Graduate School of Life and Environmental Science, Shimane University, 1060 Nishikawatsu-Cho, Matsue, Shimane 690-8504, Japan
| | - Koichi Kurata
- Graduate School of Life and Environmental Science, Shimane University, 1060 Nishikawatsu-Cho, Matsue, Shimane 690-8504, Japan
| | - Keisuke Yoshikiyo
- Graduate School of Natural Science and Technology, Shimane University, 1060 Nishikawatsu-Cho, Matsue, Shimane 690-8504, Japan
- Graduate School of Life and Environmental Science, Shimane University, 1060 Nishikawatsu-Cho, Matsue, Shimane 690-8504, Japan
- Institute of Agricultural and Life Sciences, Academic Assembly, Shimane University, 1060 Nishikawatsu-Cho, Matsue, Shimane 690-8504, Japan
| | - Ayumi Hashiguchi
- Graduate School of Natural Science and Technology, Shimane University, 1060 Nishikawatsu-Cho, Matsue, Shimane 690-8504, Japan
- Graduate School of Life and Environmental Science, Shimane University, 1060 Nishikawatsu-Cho, Matsue, Shimane 690-8504, Japan
- Institute of Environmental Systems Science, Academic Assembly, Shimane University, 1060 Nishikawatsu-Cho, Matsue, Shimane 690-8504, Japan
- Estuary Research Center, Shimane University, 1060 Nishikawatsu-Cho, Matsue, Shimane 690-8504, Japan
| | - Kunihiro Okano
- Faculty of Bioresource Sciences, Akita Prefectural University, Akita 010-0195, Japan
| | - Norio Sugiura
- Faculty of Life and Environmental Sciences, University of Tsukuba, Ibaraki 305-8572, Japan
| | - Kazuya Shimizu
- Faculty of Life Sciences, Toyo University, Gunma 374-0193, Japan
| | - Hidehisa Shimizu
- Graduate School of Natural Science and Technology, Shimane University, 1060 Nishikawatsu-Cho, Matsue, Shimane 690-8504, Japan
- Graduate School of Life and Environmental Science, Shimane University, 1060 Nishikawatsu-Cho, Matsue, Shimane 690-8504, Japan
- Institute of Agricultural and Life Sciences, Academic Assembly, Shimane University, 1060 Nishikawatsu-Cho, Matsue, Shimane 690-8504, Japan
- Estuary Research Center, Shimane University, 1060 Nishikawatsu-Cho, Matsue, Shimane 690-8504, Japan
- Raman Project Center for Medical and Biological Applications, Shimane University, 1060 Nishikawatsu-Cho, Matsue, Shimane 690-8504, Japan
- Project Center for Fortification of Local Specialty Food Functions, Shimane University, 1060 Nishikawatsu-Cho, Matsue, Shimane 690-8504, Japan
- Interdisciplinary Center for Science Research, Shimane University, 1060 Nishikawatsu-Cho, Matsue, Shimane 690-8504, Japan
- Correspondence to: Institute of Agricultural and Life Sciences, Academic Assembly, Shimane University, 1060 Nishikawatsu-Cho, Matsue, Shimane 690-8504, Japan.
| |
Collapse
|
20
|
Differential Effect of Hydroxen Peroxide οn Toxic Cyanobacteria of Hypertrophic Mediterranean Waterbodies. SUSTAINABILITY 2021. [DOI: 10.3390/su14010123] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cyanobacterial blooms have been known since ancient times; however, they are currently increasing globally. Human and ecological health risks posed by harmful cyanobacterial blooms have been recorded around the world. These risks are mainly associated with their ability to affect the ecosystem chain by different mechanisms like the production of cyanotoxins, especially microcystins. Their expansion and their harmful effects have led many researchers to seek techniques and strategies to control them. Among them, hydrogen peroxide could be a promising tool against cyanobacteria and cyanotoxins and it is well-established as an environmentally friendly oxidizing agent because of its rapid decomposition into oxygen and water. The aim of the present study was to evaluate the effect of hydrogen peroxide on phytoplankton from two hypertrophic waterbodies in Greece. The effect of hydrogen peroxide on concentration of microcystins found in the waterbodies was also studied. Treatment with 4 mg/L hydrogen peroxide was applied to water samples originated from the waterbodies and Cyanobacterial composition and biomass, phycocyanin, chlorophyll-a, and intra-cellular and total microcystin concentrations were studied. Cyanobacterial biomass and phycocyanin was reduced significantly after the application of 4 mg/L hydrogen peroxide in water treatment experiments while chlorophytes and extra-cellular microcystin concentrations were increased. Raphidiopsis (Cylindrospermopsis) raciborskii was the most affected cyanobacterial species after treatment of the water of the Karla Reservoir in comparison to Aphanizomenon favaloroi, Planktolyngbya limnetica, and Chroococcus sp. Furthermore, Microcystis aeruginosa was more resistant to the treatment of Pamvotis lake water in comparison with Microcystis wesenbergii and Microcystis panniformis. Our study showed that hydrogen peroxide differentially impacts the members of the phytoplankton community, affecting, thus, its overall efficacy. Different effects of hydrogen peroxide treatment were observed among cyanobacerial genera as well as among cyanobacterial species of the same genus. Different effects could be the result of the different resistance mechanisms of each genus or species to hydrogen peroxide. Hydrogen peroxide could be used as a treatment for the mitigation of cyanobacterial blooms in a waterbody; however, the biotic and abiotic characteristics of the waterbody should be considered.
Collapse
|
21
|
Kucheriavaia D, Veličković D, Peraino N, Lad A, Kennedy DJ, Haller ST, Westrick JA, Isailovic D. Toward Revealing Microcystin Distribution in Mouse Liver Tissue Using MALDI-MS Imaging. Toxins (Basel) 2021; 13:709. [PMID: 34679004 PMCID: PMC8538440 DOI: 10.3390/toxins13100709] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/28/2021] [Accepted: 09/28/2021] [Indexed: 01/31/2023] Open
Abstract
Cyanotoxins can be found in water and air during cyanobacterial harmful algal blooms (cHABs) in lakes and rivers. Therefore, it is very important to monitor their potential uptake by animals and humans as well as their health effects and distribution in affected organs. Herein, the distribution of hepatotoxic peptide microcystin-LR (MC-LR) is investigated in liver tissues of mice gavaged with this most common MC congener. Preliminary matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) imaging experiments performed using a non-automated MALDI matrix deposition device and a MALDI-time-of-flight (TOF) mass spectrometer yielded ambiguous results in terms of MC-LR distribution in liver samples obtained from MC-LR-gavaged mice. The tissue preparation for MALDI-MS imaging was improved by using an automated sprayer for matrix deposition, and liver sections were imaged using an Nd:YAG MALDI laser coupled to a 15 Tesla Fourier-transform ion cyclotron resonance (FT-ICR)-mass spectrometer. MALDI-FT-ICR-MS imaging provided unambiguous detection of protonated MC-LR (calculated m/z 995.5560, z = +1) and the sodium adduct of MC-LR (m/z 1017.5380, z = +1) in liver sections from gavaged mice with great mass accuracy and ultra-high mass resolution. Since both covalently bound and free MC-LR can be found in liver of mice exposed to this toxin, the present results indicate that the distribution of free microcystins in tissue sections from affected organs, such as liver, can be monitored with high-resolution MALDI-MS imaging.
Collapse
Affiliation(s)
- Daria Kucheriavaia
- Department of Chemistry and Biochemistry, University of Toledo, Toledo, OH 43606, USA;
| | | | - Nicholas Peraino
- Department of Chemistry, Wayne State University, Detroit, MI 48202, USA; (N.P.); (J.A.W.)
| | - Apurva Lad
- Department of Medicine, University of Toledo Medical Campus, Toledo, OH 43614, USA; (A.L.); (D.J.K.); (S.T.H.)
| | - David J. Kennedy
- Department of Medicine, University of Toledo Medical Campus, Toledo, OH 43614, USA; (A.L.); (D.J.K.); (S.T.H.)
| | - Steven T. Haller
- Department of Medicine, University of Toledo Medical Campus, Toledo, OH 43614, USA; (A.L.); (D.J.K.); (S.T.H.)
| | - Judy A. Westrick
- Department of Chemistry, Wayne State University, Detroit, MI 48202, USA; (N.P.); (J.A.W.)
| | - Dragan Isailovic
- Department of Chemistry and Biochemistry, University of Toledo, Toledo, OH 43606, USA;
| |
Collapse
|
22
|
Fournier C, Riehle E, Dietrich DR, Schleheck D. Is Toxin-Producing Planktothrix sp. an Emerging Species in Lake Constance? Toxins (Basel) 2021; 13:toxins13090666. [PMID: 34564670 PMCID: PMC8472890 DOI: 10.3390/toxins13090666] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 09/13/2021] [Accepted: 09/15/2021] [Indexed: 01/04/2023] Open
Abstract
Recurring blooms of filamentous, red-pigmented and toxin-producing cyanobacteria Planktothrix rubescens have been reported in numerous deep and stratified prealpine lakes, with the exception of Lake Constance. In a 2019 and 2020 Lake Constance field campaign, we collected samples from a distinct red-pigmented biomass maximum below the chlorophyll-a maximum, which was determined using fluorescence probe measurements at depths between 18 and 20 m. Here, we report the characterization of these deep water red pigment maxima (DRM) as cyanobacterial blooms. Using 16S rRNA gene-amplicon sequencing, we found evidence that the blooms were, indeed, contributed by Planktothrix spp., although phycoerythrin-rich Synechococcus taxa constituted most of the biomass (>96% relative read abundance) of the cyanobacterial DRM community. Through UPLC-MS/MS, we also detected toxic microcystins (MCs) in the DRM in the individual sampling days at concentrations of ≤1.5 ng/L. Subsequently, we reevaluated the fluorescence probe measurements collected over the past decade and found that, in the summer, DRM have been present in Lake Constance, at least since 2009. Our study highlights the need for a continuous monitoring program also targeting the cyanobacterial DRM in Lake Constance, and for future studies on the competition of the different cyanobacterial taxa. Future studies will address the potential community composition changes in response to the climate change driven physiochemical and biological parameters of the lake.
Collapse
Affiliation(s)
- Corentin Fournier
- Microbial Ecology and Limnic Microbiology, University of Konstanz, 78457 Konstanz, Germany;
| | - Eva Riehle
- Human and Environmental Toxicology, University of Konstanz, 78457 Konstanz, Germany;
| | - Daniel R. Dietrich
- Human and Environmental Toxicology, University of Konstanz, 78457 Konstanz, Germany;
- Correspondence: (D.R.D.); (D.S.)
| | - David Schleheck
- Microbial Ecology and Limnic Microbiology, University of Konstanz, 78457 Konstanz, Germany;
- Limnological Institute, University of Konstanz, 78457 Konstanz, Germany
- Correspondence: (D.R.D.); (D.S.)
| |
Collapse
|
23
|
Arman T, Clarke JD. Microcystin Toxicokinetics, Molecular Toxicology, and Pathophysiology in Preclinical Rodent Models and Humans. Toxins (Basel) 2021; 13:toxins13080537. [PMID: 34437407 PMCID: PMC8402503 DOI: 10.3390/toxins13080537] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 07/23/2021] [Accepted: 07/27/2021] [Indexed: 02/06/2023] Open
Abstract
Microcystins are ubiquitous toxins produced by photoautotrophic cyanobacteria. Human exposures to microcystins occur through the consumption of contaminated drinking water, fish and shellfish, vegetables, and algal dietary supplements and through recreational activities. Microcystin-leucine-arginine (MCLR) is the prototypical microcystin because it is reported to be the most common and toxic variant and is the only microcystin with an established tolerable daily intake of 0.04 µg/kg. Microcystin toxicokinetics is characterized by low intestinal absorption, rapid and specific distribution to the liver, moderate metabolism to glutathione and cysteinyl conjugates, and low urinary and fecal excretion. Molecular toxicology involves covalent binding to and inhibition of protein phosphatases, oxidative stress, cell death (autophagy, apoptosis, necrosis), and cytoskeleton disruption. These molecular and cellular effects are interconnected and are commonly observed together. The main target organs for microcystin toxicity are the intestine, liver, and kidney. Preclinical data indicate microcystins may also have nervous, pulmonary, cardiac, and reproductive system toxicities. Recent evidence suggests that exposure to other hepatotoxic insults could potentiate microcystin toxicity and increase the risk for chronic diseases. This review summarizes the current knowledge for microcystin toxicokinetics, molecular toxicology, and pathophysiology in preclinical rodent models and humans. More research is needed to better understand human toxicokinetics and how multifactorial exposures contribute to disease pathogenesis and progression.
Collapse
|
24
|
Kerk D, Mattice JF, Valdés-Tresanco ME, Noskov SY, Ng KKS, Moorhead GB. The origin and radiation of the phosphoprotein phosphatase (PPP) enzymes of Eukaryotes. Sci Rep 2021; 11:13681. [PMID: 34211082 PMCID: PMC8249667 DOI: 10.1038/s41598-021-93206-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 06/22/2021] [Indexed: 11/18/2022] Open
Abstract
Phosphoprotein phosphatase (PPP) enzymes are ubiquitous proteins involved in cellular signaling pathways and other functions. Here we have traced the origin of the PPP sequences of Eukaryotes and their radiation. Using a bacterial PPP Hidden Markov Model (HMM) we uncovered "BacterialPPP-Like" sequences in Archaea. A HMM derived from eukaryotic PPP enzymes revealed additional, unique sequences in Archaea and Bacteria that were more like the eukaryotic PPP enzymes then the bacterial PPPs. These sequences formed the basis of phylogenetic tree inference and sequence structural analysis allowing the history of these sequence types to be elucidated. Our phylogenetic tree data strongly suggest that eukaryotic PPPs ultimately arose from ancestors in the Asgard archaea. We have clarified the radiation of PPPs within Eukaryotes, substantially expanding the range of known organisms with PPP subtypes (Bsu1, PP7, PPEF/RdgC) previously thought to have a more restricted distribution. Surprisingly, sequences from the Methanosarcinaceae (Euryarchaeota) form a strongly supported sister group to eukaryotic PPPs in our phylogenetic analysis. This strongly suggests an intimate association between an Asgard ancestor and that of the Methanosarcinaceae. This is highly reminiscent of the syntrophic association recently demonstrated between the cultured Lokiarchaeal species Prometheoarchaeum and a methanogenic bacterial species.
Collapse
Affiliation(s)
- David Kerk
- Department of Biological Sciences, University of Calgary, 2500 University Dr. NW, Calgary, AB, T2N 1N4, Canada
| | - Jordan F Mattice
- Department of Biological Sciences, University of Calgary, 2500 University Dr. NW, Calgary, AB, T2N 1N4, Canada
| | - Mario E Valdés-Tresanco
- Department of Biological Sciences, University of Calgary, 2500 University Dr. NW, Calgary, AB, T2N 1N4, Canada
| | - Sergei Yu Noskov
- Department of Biological Sciences, University of Calgary, 2500 University Dr. NW, Calgary, AB, T2N 1N4, Canada
| | - Kenneth K-S Ng
- Department of Biological Sciences, University of Calgary, 2500 University Dr. NW, Calgary, AB, T2N 1N4, Canada
- Department of Chemistry and Biochemistry, University of Windsor, 401 Sunset Avenue, Windsor, ON, N9B 3P4, Canada
| | - Greg B Moorhead
- Department of Biological Sciences, University of Calgary, 2500 University Dr. NW, Calgary, AB, T2N 1N4, Canada.
| |
Collapse
|
25
|
Zhu R, Wang H, Shen H, Deng X, Chen J. The dynamics and release characteristics of microcystins in the plateau Lake Erhai, Southwest China. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:23473-23481. [PMID: 33452641 DOI: 10.1007/s11356-020-12312-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 12/30/2020] [Indexed: 06/12/2023]
Abstract
Microcystins (MCs) have seriously polluted drinking water supplies and have caused great harm to aquatic organisms and humans. Understanding the dynamics of MC concentrations and its influencing factors is necessary for drinking water safety. Many previous studies on MC pollution focused on intracellular MCs rather than on extracellular MCs, which are more difficult to remove by water treatment. So far, the release characteristics of MCs and the relationships between intracellular and extracellular MCs are still unclear. To explore these questions, a survey was conducted at 18 sites across Lake Erhai from May 2014 to April 2015 as in Lake Erhai the frequency and coverage area of cyanobacterial blooms have been increasing. Variation of extracellular MCs lagged behind that of intracellular MCs. The highest value of intracellular MCs was 1.07 μg L-1 in October 2014 and the highest extracellular MC concentration was 0.035 μg L-1 in November 2014. Intracellular MCs were positively influenced by MC-producing cyanobacterial biomass, water temperature (WT), pH, and conductivity (Cond). The extracellular MCs showed little correlation with cyanobacterial abundances and intracellular MC concentrations, but showed significant negative correlations with WT, pH, and Cond. These results indicated that high biomass and high intracellular MC concentrations did not quickly lead to large releases of MCs, and that when cyanobacterial cells died and blooms disappeared, MCs were intensively released into the water, posing the greatest threat to drinking water supply.
Collapse
Affiliation(s)
- Rong Zhu
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, People's Republic of China
- Marine Fisheries Research Institute of Zhejiang, Zhoushan, 316021, People's Republic of China
| | - Huan Wang
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, People's Republic of China
| | - Hong Shen
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, People's Republic of China
| | - Xuwei Deng
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, People's Republic of China
| | - Jun Chen
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, People's Republic of China.
| |
Collapse
|
26
|
Lee J, Lee S, Mayta A, Mrdjen I, Weghorst C, Knobloch T. Microcystis toxin-mediated tumor promotion and toxicity lead to shifts in mouse gut microbiome. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 206:111204. [PMID: 32871519 DOI: 10.1016/j.ecoenv.2020.111204] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 08/07/2020] [Accepted: 08/19/2020] [Indexed: 06/11/2023]
Abstract
Microcystins (MCs) are the most prevalent cyanotoxins reported in freshwater. While numerous studies have examined the toxicological impacts of MCs on mammalian systems, very few have examined the chronic impacts of MCs on the gut microbiome of exposed organisms. Our understanding of the relationship of MCs, especially lysed toxic cyanobacteria, and the gut microbiota is very limited. The objective of this study was to determine the impacts of MC-LR and Microcystis lysate ingestion on the gut microbiome in a hepatocellular carcinoma mouse model, simulating a high-risk population and exposure at an environmentally relevant MC level. Mice were assigned to 4 groups (MC-LR; Microcystis lysate; Negative control; Positive (liver carcinogen) control). Fecal samples were collected every 8 weeks. Bacterial community and colony counts were analyzed. The abundance of Firmicutes in the positive control and lysate group was higher than the negative control and MC group. Exposure to MC-LR or lysate was associated with significantly decreased bacterial diversity. A distinct separation of the three groups (MC-LR/lysate/carcinogen) from the negative was much more apparent in their gut microbiome as the exposure time increased. The MC-LR and lysate groups showed gut microbiome structure responding to lipid metabolism disturbance and high stress. Bacterial colony count was significantly lower in all the treated groups than the negative control. Our study highlights that chronic exposure to MC-LR and Microcystis lysate negatively impacts gut microbiome succession and altered the bacterial community structure into the one similar to the carcinogen group, which may indicate that the change favors progression of hepatocellular carcinoma. In a future study, more in-depth investigation is warranted to better understand the liver-gut nexus in promoting liver cancer among those exposed to MC and toxic cyanobacteria.
Collapse
Affiliation(s)
- Jiyoung Lee
- Division of Environmental Health Sciences, College of Public Health, The Ohio State University, 1841 Neil Avenue, Columbus, OH, United States; Department of Food Science & Technology, The Ohio State University, 2015 Fyffe Road, Columbus, OH, United States.
| | - Seungjun Lee
- Division of Environmental Health Sciences, College of Public Health, The Ohio State University, 1841 Neil Avenue, Columbus, OH, United States
| | - Alba Mayta
- Department of Food Science & Technology, The Ohio State University, 2015 Fyffe Road, Columbus, OH, United States
| | - Igor Mrdjen
- Division of Environmental Health Sciences, College of Public Health, The Ohio State University, 1841 Neil Avenue, Columbus, OH, United States
| | - Christopher Weghorst
- Division of Environmental Health Sciences, College of Public Health, The Ohio State University, 1841 Neil Avenue, Columbus, OH, United States
| | - Thomas Knobloch
- Division of Environmental Health Sciences, College of Public Health, The Ohio State University, 1841 Neil Avenue, Columbus, OH, United States
| |
Collapse
|
27
|
Free or Protein-Bound Microcystin Accumulation by Freshwater Bivalves as a Tool to Evaluate Water Contamination by Microcystin-Producing Cyanobacteria? APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10103426] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Cyanobacterial proliferations display rapid spatiotemporal variations that can interfere in the assessment of water contamination levels by microcystins (MC), and make necessary the use of integrative tools. This study evaluates the pertinence of bivalves Anodonta anatina and Dreissena polymorpha as bioindicators of the presence of MC-producing cyanobacteria in water. Ingested MC accumulates into two fractions in bivalve tissues—the cellular free and the protein-bound fractions—both forming the total MC fraction. Mussels were exposed to the cyanobacteria Planktothrix agardhii at densities producing an equivalent of 1, 10 and 100 µg/L of intracellular MC, with the evaluation of: (i) cyanobacterial cells and MC daily intake by mussels, (ii) free and total MC kinetics in whole individuals (using all the tissues) or only in the digestive gland, during and after the exposure, (iii) bioaccumulation factors. For each species, the kinetics of the two accumulation fractions were compared to evaluate which one best reflect levels and dynamics of MC-producing cyanobacteria in water. Results showed that the dynamic of free MC in bivalve tissues better highlight the dynamic of intracellular MC in water. Using whole D. polymorpha may be appropriate to reveal and discriminate the water contamination levels above densities of cyanobacteria producing 1 µg MC/L. Digestive glands of A. anatina appeared more sensitive to reveal low environmental concentration, but without direct correlation with levels of water contamination. Further experimentations in situ are necessary to confirm those results in order to propose the use of freshwater bivalves for a biomonitoring of MC-producing cyanobacteria in fresh waters.
Collapse
|
28
|
Baliu-Rodriguez D, Kucheriavaia D, Palagama DSW, Lad A, O’Neill GM, Birbeck JA, Kennedy DJ, Haller ST, Westrick JA, Isailovic D. Development and Application of Extraction Methods for LC-MS Quantification of Microcystins in Liver Tissue. Toxins (Basel) 2020; 12:toxins12040263. [PMID: 32325806 PMCID: PMC7232250 DOI: 10.3390/toxins12040263] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 04/11/2020] [Accepted: 04/13/2020] [Indexed: 11/25/2022] Open
Abstract
A method was developed to extract and quantify microcystins (MCs) from mouse liver with limits of quantification (LOQs) lower than previously reported. MCs were extracted from 40-mg liver samples using 85:15 (v:v) CH3CN:H2O containing 200 mM ZnSO4 and 1% formic acid. Solid-phase extraction with a C18 cartridge was used for sample cleanup. MCs were detected and quantified using HPLC-orbitrap-MS with simultaneous MS/MS detection of the 135.08 m/z fragment from the conserved Adda amino acid for structural confirmation. The method was used to extract six MCs (MC-LR, MC-RR, MC-YR, MC-LA, MC-LF, and MC-LW) from spiked liver tissue and the MC-LR cysteine adduct (MC-LR-Cys) created by the glutathione detoxification pathway. Matrix-matched internal standard calibration curves were constructed for each MC (R2 ≥ 0.993), with LOQs between 0.25 ng per g of liver tissue (ng/g) and 0.75 ng/g for MC-LR, MC-RR, MC-YR, MC-LA, and MC-LR-Cys, and 2.5 ng/g for MC-LF and MC-LW. The protocol was applied to extract and quantify MC-LR and MC-LR-Cys from the liver of mice that had been gavaged with 50 µg or 100 µg of MC-LR per kg bodyweight and were euthanized 2 h, 4 h, or 48 h after final gavage. C57Bl/6J (wild type, control) and Leprdb/J (experiment) mice were used as a model to study non-alcoholic fatty liver disease. The Leprdb/J mice were relatively inefficient in metabolizing MC-LR into MC-LR-Cys, which is an important defense mechanism against MC-LR exposure. Trends were also observed as a function of MC-LR gavage amount and time between final MC-LR gavage and euthanasia/organ harvest.
Collapse
Affiliation(s)
- David Baliu-Rodriguez
- Department of Chemistry and Biochemistry, University of Toledo, Toledo, OH 43606, USA; (D.B.-R.); (D.K.); (D.S.W.P.)
| | - Daria Kucheriavaia
- Department of Chemistry and Biochemistry, University of Toledo, Toledo, OH 43606, USA; (D.B.-R.); (D.K.); (D.S.W.P.)
| | - Dilrukshika S. W. Palagama
- Department of Chemistry and Biochemistry, University of Toledo, Toledo, OH 43606, USA; (D.B.-R.); (D.K.); (D.S.W.P.)
| | - Apurva Lad
- Department of Medicine, University of Toledo Medical Center, Toledo, OH 43614, USA; (A.L.); (D.J.K.); (S.T.H.)
| | - Grace M. O’Neill
- Department of Chemistry, Wayne State University, Detroit, MI 48202, USA; (G.M.O.); (J.A.B.); (J.A.W.)
| | - Johnna A. Birbeck
- Department of Chemistry, Wayne State University, Detroit, MI 48202, USA; (G.M.O.); (J.A.B.); (J.A.W.)
| | - David J. Kennedy
- Department of Medicine, University of Toledo Medical Center, Toledo, OH 43614, USA; (A.L.); (D.J.K.); (S.T.H.)
| | - Steven T. Haller
- Department of Medicine, University of Toledo Medical Center, Toledo, OH 43614, USA; (A.L.); (D.J.K.); (S.T.H.)
| | - Judy A. Westrick
- Department of Chemistry, Wayne State University, Detroit, MI 48202, USA; (G.M.O.); (J.A.B.); (J.A.W.)
| | - Dragan Isailovic
- Department of Chemistry and Biochemistry, University of Toledo, Toledo, OH 43606, USA; (D.B.-R.); (D.K.); (D.S.W.P.)
- Correspondence:
| |
Collapse
|
29
|
Bolotaolo M, Kurobe T, Puschner B, Hammock BG, Hengel MJ, Lesmeister S, Teh SJ. Analysis of Covalently Bound Microcystins in Sediments and Clam Tissue in the Sacramento-San Joaquin River Delta, California, USA. Toxins (Basel) 2020; 12:E178. [PMID: 32183091 PMCID: PMC7150880 DOI: 10.3390/toxins12030178] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 03/11/2020] [Accepted: 03/11/2020] [Indexed: 11/25/2022] Open
Abstract
Harmful cyanobacterial blooms compromise human and environmental health, mainly due to the cyanotoxins they often produce. Microcystins (MCs) are the most commonly measured group of cyanotoxins and are hepatotoxic, neurotoxic, and cytotoxic. Due to MCs ability to covalently bind to proteins, quantification in complex matrices is difficult. To analyze bound and unbound MCs, analytical methods were optimized for analysis in sediment and clam tissues. A clean up step was incorporated to remove lipids, improving percent yield. This method was then applied to sediment and clam samples collected from the Sacramento-San Joaquin River Delta (Delta) in the spring and fall of 2017. Water samples were also tested for intracellular and extracellular MCs. These analyses were used to quantify the partitioning of MCs among sediment, clams, and water, and to examine whether MCs persist during non-summer months. Toxin analysis revealed that multiple sediment samples collected in the Delta were positive for MCs, with a majority of the positive samples from sites in the San Joaquin River, even while water samples from the same location were below detection limit. These data highlight the importance of analyzing MCs in complex matrices to accurately evaluate environmental risk.
Collapse
Affiliation(s)
- Melissa Bolotaolo
- Department of Anatomy, Physiology, and Cell Biology, University of California, Davis, CA 95616, USA; (T.K.); (B.G.H.); (S.J.T.)
| | - Tomofumi Kurobe
- Department of Anatomy, Physiology, and Cell Biology, University of California, Davis, CA 95616, USA; (T.K.); (B.G.H.); (S.J.T.)
| | - Birgit Puschner
- Department of Molecular Biosciences, University of California, Davis, CA 95616, USA;
- College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA
| | - Bruce G Hammock
- Department of Anatomy, Physiology, and Cell Biology, University of California, Davis, CA 95616, USA; (T.K.); (B.G.H.); (S.J.T.)
| | - Matt J. Hengel
- Department of Environmental Toxicology, University of California, Davis, CA 95616, USA;
| | - Sarah Lesmeister
- California Department of Water Resources, West Sacramento, CA 95814, USA;
| | - Swee J. Teh
- Department of Anatomy, Physiology, and Cell Biology, University of California, Davis, CA 95616, USA; (T.K.); (B.G.H.); (S.J.T.)
| |
Collapse
|
30
|
Bouaïcha N, Miles CO, Beach DG, Labidi Z, Djabri A, Benayache NY, Nguyen-Quang T. Structural Diversity, Characterization and Toxicology of Microcystins. Toxins (Basel) 2019; 11:E714. [PMID: 31817927 PMCID: PMC6950048 DOI: 10.3390/toxins11120714] [Citation(s) in RCA: 236] [Impact Index Per Article: 39.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 12/02/2019] [Accepted: 12/04/2019] [Indexed: 11/22/2022] Open
Abstract
Hepatotoxic microcystins (MCs) are the most widespread class of cyanotoxins and the one that has most often been implicated in cyanobacterial toxicosis. One of the main challenges in studying and monitoring MCs is the great structural diversity within the class. The full chemical structure of the first MC was elucidated in the early 1980s and since then, the number of reported structural analogues has grown steadily and continues to do so, thanks largely to advances in analytical methodology. The structures of some of these analogues have been definitively elucidated after chemical isolation using a combination of techniques including nuclear magnetic resonance, amino acid analysis, and tandem mass spectrometry (MS/MS). Others have only been tentatively identified using liquid chromatography-MS/MS without chemical isolation. An understanding of the structural diversity of MCs, the genetic and environmental controls for this diversity and the impact of structure on toxicity are all essential to the ongoing study of MCs across several scientific disciplines. However, because of the diversity of MCs and the range of approaches that have been taken for characterizing them, comprehensive information on the state of knowledge in each of these areas can be challenging to gather. We have conducted an in-depth review of the literature surrounding the identification and toxicity of known MCs and present here a concise review of these topics. At present, at least 279 MCs have been reported and are tabulated here. Among these, about 20% (55 of 279) appear to be the result of chemical or biochemical transformations of MCs that can occur in the environment or during sample handling and extraction of cyanobacteria, including oxidation products, methyl esters, or post-biosynthetic metabolites. The toxicity of many MCs has also been studied using a range of different approaches and a great deal of variability can be observed between reported toxicities, even for the same congener. This review will help clarify the current state of knowledge on the structural diversity of MCs as a class and the impacts of structure on toxicity, as well as to identify gaps in knowledge that should be addressed in future research.
Collapse
Affiliation(s)
- Noureddine Bouaïcha
- Écologie, Systématique et Évolution, Univ. Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, 91405 Orsay, France; (A.D.); (N.Y.B.)
| | - Christopher O. Miles
- Biotoxin Metrology, National Research Council Canada, 1411 Oxford St, Halifax, NS B3H 3Z1, Canada; (C.O.M.); (D.G.B.)
| | - Daniel G. Beach
- Biotoxin Metrology, National Research Council Canada, 1411 Oxford St, Halifax, NS B3H 3Z1, Canada; (C.O.M.); (D.G.B.)
| | - Zineb Labidi
- Laboratoire Biodiversité et Pollution des Écosystèmes, Faculté des Sciences de la Nature et de la Vie, Université Chadli Bendjedid d’El Taref, 36000 El Taref, Algeria;
| | - Amina Djabri
- Écologie, Systématique et Évolution, Univ. Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, 91405 Orsay, France; (A.D.); (N.Y.B.)
- Laboratoire Biodiversité et Pollution des Écosystèmes, Faculté des Sciences de la Nature et de la Vie, Université Chadli Bendjedid d’El Taref, 36000 El Taref, Algeria;
| | - Naila Yasmine Benayache
- Écologie, Systématique et Évolution, Univ. Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, 91405 Orsay, France; (A.D.); (N.Y.B.)
| | - Tri Nguyen-Quang
- Biofluids and Biosystems Modeling (BBML), Faculty of Agriculture, Dalhousie University, 39 Cox Road, Truro, B2N 5E3 Nova Scotia, Canada;
| |
Collapse
|
31
|
Bi X, Dai W, Wang X, Dong S, Zhang S, Zhang D, Wu M. Microcystins distribution, bioaccumulation, and Microcystis genotype succession in a fish culture pond. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 688:380-388. [PMID: 31233918 DOI: 10.1016/j.scitotenv.2019.06.156] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 05/26/2019] [Accepted: 06/10/2019] [Indexed: 06/09/2023]
Abstract
In freshwater aquaculture ponds, cyanobacterial blooms and microcystins (MCs) pollution have attracted considerable attention due to their toxic effects. To provide an insight into cyanobacterial problems in aquaculture ponds, MCs distribution, bioaccumulation, and Microcystis genotype succession in a fishpond were investigated from May 2017 to November 2017. The distribution of MCs in filtered water, seston, and sediment varied considerably among months. MCs concentrations in filtered water, seston, and sediment ranged from 1.16 to 3.66 μg/L, 0.64 to 13.98 μg/g DW, and 1.34 to 5.90 μg/g DW, respectively. In addition, chemical oxygen demand was positively correlated with sestonic MCs concentrations. MCs concentrations accumulated in different tissues of market-size fish were in the order of liver > kidney > intestine > muscle. MCs content in muscle was 4.3 times higher than the WHO recommended tolerable daily intake level. Twenty-four ITS genotypes of Microcystis were identified from a total of 653 sequences. During the survey period, considerable genotype variation and rapid genotype succession were observed and dominant genotype was absent. A redundancy analysis revealed that Microcystis genotypes could significantly influence the variations in the proportions of the potentially toxic Microcystis, which could in turn influence the MCs concentrations in seston.
Collapse
Affiliation(s)
- Xiangdong Bi
- Key Laboratory of Aquatic-Ecology and Aquaculture of Tianjin, College of Fishery, Tianjin Agricultural University, Tianjin 300384, China
| | - Wei Dai
- Key Laboratory of Aquatic-Ecology and Aquaculture of Tianjin, College of Fishery, Tianjin Agricultural University, Tianjin 300384, China.
| | - Xueying Wang
- Key Laboratory of Aquatic-Ecology and Aquaculture of Tianjin, College of Fishery, Tianjin Agricultural University, Tianjin 300384, China
| | - Shaojie Dong
- Key Laboratory of Aquatic-Ecology and Aquaculture of Tianjin, College of Fishery, Tianjin Agricultural University, Tianjin 300384, China
| | - Shulin Zhang
- Key Laboratory of Aquatic-Ecology and Aquaculture of Tianjin, College of Fishery, Tianjin Agricultural University, Tianjin 300384, China
| | - Dajuan Zhang
- Key Laboratory of Aquatic-Ecology and Aquaculture of Tianjin, College of Fishery, Tianjin Agricultural University, Tianjin 300384, China
| | - Miao Wu
- Department of Molecular Sciences, PO Box 7015, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden.
| |
Collapse
|
32
|
Diagnosing Microcystin Intoxication of Canines: Clinicopathological Indications, Pathological Characteristics, and Analytical Detection in Postmortem and Antemortem Samples. Toxins (Basel) 2019; 11:toxins11080456. [PMID: 31382600 PMCID: PMC6722975 DOI: 10.3390/toxins11080456] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 07/28/2019] [Accepted: 08/01/2019] [Indexed: 12/24/2022] Open
Abstract
In the summer of 2018, six dogs exposed to a harmful algal bloom (HAB) of Microcystis in Martin County Florida (USA) developed clinicopathological signs of microcystin (MC) intoxication (i.e., acute vomiting, diarrhea, severe thrombocytopenia, elevated alanine aminotransferase, hemorrhage). Successful supportive veterinary care was provided and led to survival of all but one patient. Confirmation of MC intoxication was made through interpretation of clinicopathological abnormalities, pathological examination of tissues, microscopy (vomitus), and analytical MC testing of antemortem/postmortem samples (vomitus, blood, urine, bile, liver, kidney, hair). Gross and microscopic examination of the deceased patient confirmed massive hepatic necrosis, mild multifocal renal tubular necrosis, and hemorrhage within multiple organ systems. Microscopy of a vomitus sample confirmed the presence of Microcystis. Three analytical MC testing approaches were used, including the MMPB (2-methyl-3-methoxy-4-phenylbutyric acid) technique, targeted congener analysis (e.g., liquid chromatography tandem-mass spectrometry of MC-LR), and enzyme-linked immunosorbent assay (ELISA). Total Adda MCs (as MMPB) were confirmed in the liver, bile, kidney, urine, and blood of the deceased dog. Urinalysis (MMPB) of one surviving dog showed a high level of MCs (32,000 ng mL−1) 1-day post exposure, with MCs detectable >2 months post exposure. Furthermore, hair from a surviving dog was positive for MMPB, illustrating another testable route of MC elimination in canines. The described cases represent the first use of urine as an antemortem, non-invasive specimen to diagnose microcystin toxicosis. Antemortem diagnostic testing to confirm MC intoxication cases, whether acute or chronic, is crucial for providing optimal supportive care and mitigating MC exposure.
Collapse
|
33
|
Accumulation of Microcystin-LR in Grains of Two Rice Varieties ( Oryza sativa L.) and a Leafy Vegetable, Ipomoea aquatica. Toxins (Basel) 2019; 11:toxins11080432. [PMID: 31344839 PMCID: PMC6722703 DOI: 10.3390/toxins11080432] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 07/15/2019] [Accepted: 07/18/2019] [Indexed: 11/29/2022] Open
Abstract
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.
Collapse
|
34
|
Huang IS, Zimba PV. Cyanobacterial bioactive metabolites-A review of their chemistry and biology. HARMFUL ALGAE 2019; 86:139-209. [PMID: 31358273 DOI: 10.1016/j.hal.2019.05.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 09/14/2018] [Accepted: 11/16/2018] [Indexed: 06/10/2023]
Abstract
Cyanobacterial blooms occur when algal densities exceed baseline population concentrations. Cyanobacteria can produce a large number of secondary metabolites. Odorous metabolites affect the smell and flavor of aquatic animals, whereas bioactive metabolites cause a range of lethal and sub-lethal effects in plants, invertebrates, and vertebrates, including humans. Herein, the bioactivity, chemistry, origin, and biosynthesis of these cyanobacterial secondary metabolites were reviewed. With recent revision of cyanobacterial taxonomy by Anagnostidis and Komárek as part of the Süβwasserflora von Mitteleuropa volumes 19(1-3), names of many cyanobacteria that produce bioactive compounds have changed, thereby confusing readers. The original and new nomenclature are included in this review to clarify the origins of cyanobacterial bioactive compounds. Due to structural similarity, the 157 known bioactive classes produced by cyanobacteria have been condensed to 55 classes. This review will provide a basis for more formal procedures to adopt a logical naming system. This review is needed for efficient management of water resources to understand, identify, and manage cyanobacterial harmful algal bloom impacts.
Collapse
Affiliation(s)
- I-Shuo Huang
- Center for Coastal Studies, Texas A&M University-Corpus Christi, 6300 Ocean Drive, Corpus Christi, TX 78412, USA.
| | - Paul V Zimba
- Center for Coastal Studies, Texas A&M University-Corpus Christi, 6300 Ocean Drive, Corpus Christi, TX 78412, USA
| |
Collapse
|
35
|
Bogart JW, Bowers AA. Dehydroamino acids: chemical multi-tools for late-stage diversification. Org Biomol Chem 2019; 17:3653-3669. [PMID: 30849157 PMCID: PMC6637761 DOI: 10.1039/c8ob03155j] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
α,β-Dehydroamino acids (dhAAs) are noncanonical amino acids that are found in a wide array of natural products and can be easily installed into peptides and proteins. dhAAs exhibit remarkable synthetic flexibility, readily undergoing a number of reactions, such as polar and single-electron additions, transition metal catalyzed cross-couplings, and cycloadditions. Because of the relatively mild conditions required for many of these reactions, dhAAs are increasingly being used as orthogonal chemical handles for late-stage modification of biomolecules. Still, only a fraction of the chemical reactivity of dhAAs has been exploited in such biorthogonal applications. Herein, we provide an overview of the broad spectrum of chemical reactivity of dhAAs, with special emphasis on recent efforts to adapt such transformations for biomolecules such as natural products, peptides, and proteins. We also discuss examples of enzymes from natural product biosynthetic pathways that have been found to catalyze many similar reactions; these enzymes provide mild, regio- and stereoselective, biocatalytic alternatives for future development. We anticipate that the continued investigation of the innate reactivity of dhAAs will furnish a diverse portfolio dhAA-based chemistries for use in chemical biology and drug discovery.
Collapse
Affiliation(s)
- Jonathan W Bogart
- Division of Chemical Biology and Medicinal Chemistry Eshelman School of Pharmacy, and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
| | | |
Collapse
|
36
|
Vasudevan A, Argiriadi MA, Baranczak A, Friedman MM, Gavrilyuk J, Hobson AD, Hulce JJ, Osman S, Wilson NS. Covalent binders in drug discovery. PROGRESS IN MEDICINAL CHEMISTRY 2019; 58:1-62. [PMID: 30879472 DOI: 10.1016/bs.pmch.2018.12.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Covalent modulation of protein function can have multiple utilities including therapeutics, and probes to interrogate biology. While this field is still viewed with scepticism due to the potential for (idiosyncratic) toxicities, significant strides have been made in terms of understanding how to tune electrophilicity to selectively target specific residues. Progress has also been made in harnessing the potential of covalent binders to uncover novel biology and to provide an enhanced utility as payloads for Antibody Drug Conjugates. This perspective covers the tenets and applications of covalent binders.
Collapse
Affiliation(s)
| | | | | | | | - Julia Gavrilyuk
- AbbVie Stemcentrx, LLC, South San Francisco, CA, United States
| | | | | | - Sami Osman
- AbbVie Bioresearch Center, Worcester, MA, United States
| | | |
Collapse
|
37
|
Wang Q, Liu Y, Guo J, Lin S, Wang Y, Yin T, Gregersen H, Hu T, Wang G. Microcystin-LR induces angiodysplasia and vascular dysfunction through promoting cell apoptosis by the mitochondrial signaling pathway. CHEMOSPHERE 2019; 218:438-448. [PMID: 30485828 DOI: 10.1016/j.chemosphere.2018.11.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 10/25/2018] [Accepted: 11/02/2018] [Indexed: 06/09/2023]
Abstract
The harmful algal blooms are becoming increasingly problematic in the regions that drinking water production depends on surface waters. With a global occurrence, microcystins are toxic peptides produced by multiple cyanobacterial genera in the harmful algal blooms. In this study, we examined the effects of microcystin-LR (MC-LR), a representative toxin of the microcystin family, on vascular development in zebrafish and the apoptosis of human umbilical vein endothelial cells (HUVECs). In zebrafish larvae, MC-LR induced angiodysplasia, damaged vascular structures and reduced lumen size at 0.1 μM and 1 μM, leading to the decrease of the blood flow area in the blood vessels and brain hemorrhage, which showed that MC-LR could dose-dependently inhibit vascular development and cause vascular dysfunction. In MC-LR treated HUVECs, the proportion of early apoptosis and late apoptosis cells increased in a concentration-dependent manner. Different concentrations of MC-LR could also activate caspase 3/9 in HUVECs, increase the level of mitochondrial ROS and reduce mitochondrial membrane potential. Additionally, MC-LR could promote the expression of p53 and inhibit the expression of PCNA. The findings showed that MC-LR could promote apoptosis of HUVECs through the mitochondrial signaling pathway. Combined with these results, MC-LR may promote vascular endothelial cell apoptosis through mitochondrial signaling pathway, leading to angiodysplasia and vascular dysfunction.
Collapse
Affiliation(s)
- Qilong Wang
- Key Laboratory for Biorheological Science and Technology of Ministry of Education (Chongqing University), State and Local Joint Engineering Laboratory for Vascular Implants (Chongqing), Bioengineering College of Chongqing University, Chongqing 400030, China
| | - Yuanli Liu
- Key Laboratory for Biorheological Science and Technology of Ministry of Education (Chongqing University), State and Local Joint Engineering Laboratory for Vascular Implants (Chongqing), Bioengineering College of Chongqing University, Chongqing 400030, China
| | - Jingsong Guo
- Key Laboratory of the Three Gorges Reservoir's Eco-Environments of MOE, Chongqing University, Chongqing 400045, China
| | - Song Lin
- Key Laboratory for Biorheological Science and Technology of Ministry of Education (Chongqing University), State and Local Joint Engineering Laboratory for Vascular Implants (Chongqing), Bioengineering College of Chongqing University, Chongqing 400030, China
| | - Yeqi Wang
- Key Laboratory for Biorheological Science and Technology of Ministry of Education (Chongqing University), State and Local Joint Engineering Laboratory for Vascular Implants (Chongqing), Bioengineering College of Chongqing University, Chongqing 400030, China
| | - Tieying Yin
- Key Laboratory for Biorheological Science and Technology of Ministry of Education (Chongqing University), State and Local Joint Engineering Laboratory for Vascular Implants (Chongqing), Bioengineering College of Chongqing University, Chongqing 400030, China
| | - Hans Gregersen
- Key Laboratory for Biorheological Science and Technology of Ministry of Education (Chongqing University), State and Local Joint Engineering Laboratory for Vascular Implants (Chongqing), Bioengineering College of Chongqing University, Chongqing 400030, China
| | - Tingzhang Hu
- Key Laboratory for Biorheological Science and Technology of Ministry of Education (Chongqing University), State and Local Joint Engineering Laboratory for Vascular Implants (Chongqing), Bioengineering College of Chongqing University, Chongqing 400030, China.
| | - Guixue Wang
- Key Laboratory for Biorheological Science and Technology of Ministry of Education (Chongqing University), State and Local Joint Engineering Laboratory for Vascular Implants (Chongqing), Bioengineering College of Chongqing University, Chongqing 400030, China.
| |
Collapse
|
38
|
Huang IS, Zimba PV. Cyanobacterial bioactive metabolites-A review of their chemistry and biology. HARMFUL ALGAE 2019; 83:42-94. [PMID: 31097255 DOI: 10.1016/j.hal.2018.11.008] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 09/14/2018] [Accepted: 11/16/2018] [Indexed: 06/09/2023]
Abstract
Cyanobacterial blooms occur when algal densities exceed baseline population concentrations. Cyanobacteria can produce a large number of secondary metabolites. Odorous metabolites affect the smell and flavor of aquatic animals, whereas bioactive metabolites cause a range of lethal and sub-lethal effects in plants, invertebrates, and vertebrates, including humans. Herein, the bioactivity, chemistry, origin, and biosynthesis of these cyanobacterial secondary metabolites were reviewed. With recent revision of cyanobacterial taxonomy by Anagnostidis and Komárek as part of the Süβwasserflora von Mitteleuropa volumes 19(1-3), names of many cyanobacteria that produce bioactive compounds have changed, thereby confusing readers. The original and new nomenclature are included in this review to clarify the origins of cyanobacterial bioactive compounds. Due to structural similarity, the 157 known bioactive classes produced by cyanobacteria have been condensed to 55 classes. This review will provide a basis for more formal procedures to adopt a logical naming system. This review is needed for efficient management of water resources to understand, identify, and manage cyanobacterial harmful algal bloom impacts.
Collapse
Affiliation(s)
- I-Shuo Huang
- Center for Coastal Studies, Texas A&M University Corpus Christi, 6300 Ocean Drive, Corpus Christi, TX 78412, USA.
| | - Paul V Zimba
- Center for Coastal Studies, Texas A&M University Corpus Christi, 6300 Ocean Drive, Corpus Christi, TX 78412, USA
| |
Collapse
|
39
|
Hu C, Lee J. A Novel Proof-of-Concept Sandwich Immunoassay for Screening Microcystin in Cyanobacteria Based on Michael Addition Reaction. ANAL SCI 2019; 35:107-111. [PMID: 30298821 DOI: 10.2116/analsci.18sdn03] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We present an innovative concept of a screening tool for detecting free microcystin in cyanobacteria using a sandwich immunodetection format, based on Michael addition reaction between α,β-unsaturated carbonyl moiety of microcystin and thiol of coating substance. This proof-of-concept immunoassay was developed using bovine serum albumin as a microcystin-binding model, and was tested with toxic Microcystis samples. The preliminary results indicate that the proposed Michael addition-based immunodetection is promising and can be used as a platform for further development to become a useful tool for free microcystin analysis in various samples in the future.
Collapse
Affiliation(s)
- Chenlin Hu
- Division of Environmental Health Sciences, College of Public Health, The Ohio State University
| | - Jiyoung Lee
- Division of Environmental Health Sciences, College of Public Health, The Ohio State University.,Department of Food Science and Technology, The Ohio State University
| |
Collapse
|
40
|
Ross C, Warhurst BC, Brown A, Huff C, Ochrietor JD. Mesohaline conditions represent the threshold for oxidative stress, cell death and toxin release in the cyanobacterium Microcystis aeruginosa. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2019; 206:203-211. [PMID: 30500607 DOI: 10.1016/j.aquatox.2018.11.019] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 11/20/2018] [Accepted: 11/21/2018] [Indexed: 06/09/2023]
Abstract
As aquatic ecosystems become increasingly affected by hydrologic alterations, drought and sea level rise a need exists to better understand the biological effects of elevated salinity on toxigenic cyanobacteria such as Microcystis aeruginosa. This study investigated the impacts of oligohaline/low mesohaline conditions and exposure time on selected physiological and biochemical responses in M. aeruginosa including cell viability, oxidative stress, antioxidant responses, in addition to microcystin synthesis and release into the surrounding environment. M. aeruginosa was able to grow in most test salinity treatments (1.4-10 ppt), as supported by cell abundance data and chlorophyll-a (chl-a) concentrations. Physiological data showed that after certain salinity thresholds (∼7ppt) were surpassed, salt stress had cascading effects, such as increased ROS production and lipid peroxidation, potentiating the decline in cellular viability. Furthermore, elevated salinity induced oxidative stress which was concomitant with a decrease in cell abundance, chl-a concentration and photochemical efficiency in the 7-10 ppt treatments. M. aeruginosa did not synthesize microcystins (MCs) in response to increased saline conditions, and mcy-D expression was not correlated with either salinity treatment or extracellular MC concentrations, indicating that salinity stress could inhibit toxin production and that released toxins were likely synthesized prior to exposure. Additionally, extracellular MC concentrations were not correlated with decreased cellular integrity, as evidenced by SYTOX analyses, suggesting that toxins may be released through mechanisms other than cellular lysis. Results from this study support that M. aeruginosa can survive with limited negative impacts to cellular structure and function up to a certain threshold between 7-10 ppt. However, after these thresholds are surpassed, there is radical decline in cell health and viability leading to toxin release. This work underscores the importance of understanding the balance between ROS production and antioxidant capacities when assessing the fate of M. aeruginosa under mesohaline conditions.
Collapse
Affiliation(s)
- Cliff Ross
- Department of Biology, University of North Florida, 1 UNF Drive, Jacksonville, FL, 32224, USA.
| | - B Christopher Warhurst
- Department of Biology, University of North Florida, 1 UNF Drive, Jacksonville, FL, 32224, USA
| | - Amber Brown
- Department of Biology, University of North Florida, 1 UNF Drive, Jacksonville, FL, 32224, USA
| | - Chase Huff
- Department of Biology, University of North Florida, 1 UNF Drive, Jacksonville, FL, 32224, USA
| | - Judith D Ochrietor
- Department of Biology, University of North Florida, 1 UNF Drive, Jacksonville, FL, 32224, USA
| |
Collapse
|
41
|
The split protein phosphatase system. Biochem J 2018; 475:3707-3723. [PMID: 30523060 PMCID: PMC6282683 DOI: 10.1042/bcj20170726] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 10/29/2018] [Accepted: 11/01/2018] [Indexed: 12/14/2022]
Abstract
Reversible phosphorylation of proteins is a post-translational modification that regulates all aspect of life through the antagonistic action of kinases and phosphatases. Protein kinases are well characterized, but protein phosphatases have been relatively neglected. Protein phosphatase 1 (PP1) catalyzes the dephosphorylation of a major fraction of phospho-serines and phospho-threonines in cells and thereby controls a broad range of cellular processes. In this review, I will discuss how phosphatases were discovered, how the view that they were unselective emerged and how recent findings have revealed their exquisite selectivity. Unlike kinases, PP1 phosphatases are obligatory heteromers composed of a catalytic subunit bound to one (or two) non-catalytic subunit(s). Based on an in-depth study of two holophosphatases, I propose the following: selective dephosphorylation depends on the assembly of two components, the catalytic subunit and the non-catalytic subunit, which serves as a high-affinity substrate receptor. Because functional complementation of the two modules is required to produce a selective holophosphatase, one can consider that they are split enzymes. The non-catalytic subunit was often referred to as a regulatory subunit, but it is, in fact, an essential component of the holoenzyme. In this model, a phosphatase and its array of mostly orphan substrate receptors constitute the split protein phosphatase system. The set of potentially generalizable principles outlined in this review may facilitate the study of these poorly understood enzymes and the identification of their physiological substrates.
Collapse
|
42
|
Foss AJ, Miles CO, Samdal IA, Løvberg KE, Wilkins AL, Rise F, Jaabæk JAH, McGowan PC, Aubel MT. Analysis of free and metabolized microcystins in samples following a bird mortality event. HARMFUL ALGAE 2018; 80:117-129. [PMID: 30502804 DOI: 10.1016/j.hal.2018.10.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 09/28/2018] [Accepted: 10/15/2018] [Indexed: 06/09/2023]
Abstract
In the summer of 2012, over 750 dead and dying birds were observed at the Paul S. Sarbanes Ecosystem Restoration Project at Poplar Island, Maryland, USA (Chesapeake Bay). Clinical signs suggested avian botulism, but an ongoing dense Microcystis bloom was present in an impoundment on the island. Enzyme-linked immunosorbent assay (ELISA) analysis of a water sample indicated 6000 ng mL-1 of microcystins (MCs). LC-UV/MS analysis confirmed the presence of MC-LR and a high concentration of an unknown MC congener (m/z 1037.5). The unknown MC was purified and confirmed to be [D-Leu1]MC-LR using NMR spectroscopy, LC-HRMS and LC-MS2, which slowly converted to [D-Leu1,Glu(OMe)6]MC-LR during storage in MeOH. Lyophilized algal material from the bloom was further characterized using LC-HRMS and LC-MS2 in combination with chemical derivatizations, and an additional 24 variants were detected, including MCs conjugated to Cys, GSH and γ-GluCys and their corresponding sulfoxides. Mallard (Anas platyrhynchos) livers were tested to confirm MC exposure. Two broad-specificity MC ELISAs and LC-MS2 were used to measure free MCs, while 'total' MCs were estimated by both MMPB (3-methoxy-2-methyl-4-phenylbutyric acid) and thiol de-conjugation techniques. Free microcystins in the livers (63-112 ng g-1) accounted for 33-41% of total microcystins detected by de-conjugation and MMPB techniques. Free [D-Leu1]MC-LR was quantitated in tissues at 25-67 ng g-1 (LC-MS2). The levels of microcystin varied based on analytical method used, highlighting the need to develop a comprehensive analysis strategy to elucidate the etiology of bird mortality events when microcystin-producing HABs are present.
Collapse
Affiliation(s)
- Amanda J Foss
- GreenWater Laboratories/CyanoLab, 205 Zeagler Drive, Palatka, FL, 32177, United States.
| | - Christopher O Miles
- Norwegian Veterinary Institute, P. O. Box 750 Sentrum, N-0106, Oslo, Norway; Measurement Science and Standards, National Research Council, 1411 Oxford Street, Halifax, NS, B3H 3Z1, Canada
| | - Ingunn A Samdal
- Norwegian Veterinary Institute, P. O. Box 750 Sentrum, N-0106, Oslo, Norway
| | - Kjersti E Løvberg
- Norwegian Veterinary Institute, P. O. Box 750 Sentrum, N-0106, Oslo, Norway
| | - Alistair L Wilkins
- Norwegian Veterinary Institute, P. O. Box 750 Sentrum, N-0106, Oslo, Norway; Chemistry Department, University of Waikato, Private Bag 3105, 3240, Hamilton, New Zealand
| | - Frode Rise
- Department of Chemistry, University of Oslo, P.O. Box 1033, N-0315, Oslo, Norway
| | - J Atle H Jaabæk
- Department of Chemistry, University of Oslo, P.O. Box 1033, N-0315, Oslo, Norway
| | - Peter C McGowan
- U.S. Fish and Wildlife Service, Chesapeake Bay Field Office, Annapolis, MD, United States
| | - Mark T Aubel
- GreenWater Laboratories/CyanoLab, 205 Zeagler Drive, Palatka, FL, 32177, United States
| |
Collapse
|
43
|
Rodrigues Pires Júnior O, de Oliveira NB, Bosque RJ, Nice Ferreira MF, Morais Aurélio da Silva V, Martins Magalhães AC, Correia de Santana CJ, de Souza Castro M. Histopathological Evaluation of the Exposure by Cyanobacteria Cultive Containing [d-Leu¹]Microcystin-LR on Lithobates catesbeianus Tadpoles. Toxins (Basel) 2018; 10:toxins10080318. [PMID: 30082615 PMCID: PMC6116141 DOI: 10.3390/toxins10080318] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 07/21/2018] [Accepted: 07/24/2018] [Indexed: 01/28/2023] Open
Abstract
This study evaluated the effects of [d-Leu1]Microcystin-LR variant by the exposure of Lithobates catesbeianus tadpole to unialgal culture Microcystis aeruginosa NPLJ-4 strain. The Tadpole was placed in aquariums and exposed to Microcystis aeruginosa culture or disrupted cells. For 16 days, 5 individuals were removed every 2 days, and tissue samples of liver, skeletal muscle, and intestinal tract were collected for histopathology and bioaccumulation analyses. After exposure, those surviving tadpoles were placed in clean water for 15 days to evaluate their recovery. A control without algae and toxins was maintained in the same conditions and exhibited normal histology and no tissue damage. In exposed tadpoles, samples were characterized by serious damages that similarly affected the different organs, such as loss of adhesion between cells, nucleus fragmentation, necrosis, and hemorrhage. Samples showed signs of recovery but severe damages were still observed. Neither HPLC-PDA nor mass spectrometry analysis showed any evidence of free Microcystins bioaccumulation.
Collapse
Affiliation(s)
- Osmindo Rodrigues Pires Júnior
- Toxinology Laboratory, Depto. Physiological Sciences, Institute of Biology, University of Brasilia, Brasilia 70910-900, Brazil.
| | - Natiela Beatriz de Oliveira
- Toxinology Laboratory, Depto. Physiological Sciences, Institute of Biology, University of Brasilia, Brasilia 70910-900, Brazil.
| | - Renan J Bosque
- Depto. Genetics and Morphology, Institute of Biology, University of Brasilia, Brasilia 70910-900, Brazil.
| | | | | | - Ana Carolina Martins Magalhães
- Toxinology Laboratory, Depto. Physiological Sciences, Institute of Biology, University of Brasilia, Brasilia 70910-900, Brazil.
| | - Carlos José Correia de Santana
- Toxinology Laboratory, Depto. Physiological Sciences, Institute of Biology, University of Brasilia, Brasilia 70910-900, Brazil.
| | - Mariana de Souza Castro
- Toxinology Laboratory, Depto. Physiological Sciences, Institute of Biology, University of Brasilia, Brasilia 70910-900, Brazil.
| |
Collapse
|
44
|
Brown A, Foss A, Miller MA, Gibson Q. Detection of cyanotoxins (microcystins/nodularins) in livers from estuarine and coastal bottlenose dolphins (Tursiops truncatus) from Northeast Florida. HARMFUL ALGAE 2018; 76:22-34. [PMID: 29887202 DOI: 10.1016/j.hal.2018.04.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 04/06/2018] [Accepted: 04/30/2018] [Indexed: 05/21/2023]
Abstract
Microcystins/Nodularins (MCs/NODs) are potent hepatotoxic cyanotoxins produced by harmful algal blooms (HABs) that occur frequently in the upper basin of the St. Johns River (SJR), Jacksonville, FL, USA. Areas downstream of bloom locations provide critical habitat for an estuarine population of bottlenose dolphins (Tursiops truncatus). Since 2010, approximately 30 of these dolphins have stranded and died within this impaired watershed; the cause of death was inconclusive for a majority of these individuals. For the current study, environmental exposure to MCs/NODs was investigated as a potential cause of dolphin mortality. Stranded dolphins from 2013 to 2017 were categorized into estuarine (n = 17) and coastal (n = 10) populations. Because estuarine dolphins inhabit areas with frequent or recurring cyanoblooms, they were considered as a comparatively high-risk group for cyanotoxin exposure in relation to coastal animals. All available liver samples from estuarine dolphins were tested regardless of stranding date, and samples from coastal individuals that stranded outside of the known cyanotoxin bloom season were assessed as controls. The MMPB (2-methyl-3-methoxy-4-phenylbutiric acid) technique was used to determine total (bound and free) concentrations of MCs/NODS in liver tissues. Free MCs/NODs extractions were conducted and analyzed using ELISA and LC-MS/MS on MMPB-positive samples to compare test results. MMPB testing resulted in low-level total MCs/NODs detection in some specimens. The Adda ELISA produced high test values that were not supported by concurrent LC-MS/MS analyses, indicative of false positives. Our results indicate that both estuarine and coastal dolphins are exposed to MCs/NODs, with potential toxic and immune health impacts.
Collapse
Affiliation(s)
- Amber Brown
- University of North Florida, Department of Biology, 1 UNF Drive, Jacksonville, FL 32224, USA.
| | - Amanda Foss
- GreenWater Laboratories/CyanoLab, 205 Zeagler Drive, Palatka, FL 32177, USA
| | - Melissa A Miller
- Marine Wildlife Veterinary Care and Research Center, California Department of Fish and Wildlife, Office of Spill Prevention and Response, Santa Cruz, CA, USA; Wildlife Health Center, School of Veterinary Medicine, University of California Davis, Davis, CA, USA
| | - Quincy Gibson
- University of North Florida, Department of Biology, 1 UNF Drive, Jacksonville, FL 32224, USA
| |
Collapse
|
45
|
Evaluation of microcystin contamination in blue-green algal dietary supplements using a protein phosphatase inhibition-based test kit. Heliyon 2018; 4:e00573. [PMID: 29862339 PMCID: PMC5968134 DOI: 10.1016/j.heliyon.2018.e00573] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 01/29/2018] [Accepted: 03/08/2018] [Indexed: 11/22/2022] Open
Abstract
The cyanobacterium Aphanizomenon flos-aquae (AFA), from Upper-Klamath Lake, Oregon, are used to produce blue-green algal (BGA) dietary supplements. The periodic co-occurrence of hepatotoxin-producing contaminant species prompted the Oregon Health Division to establish a limit of 1 μg/g microcystin (MC) for products sold in Oregon in 1997. At the federal level, the current good manufacturing practice (CGMP) regulations for dietary supplements require manufacturers establish a specification, and test, for limits on contaminants that may adulterate finished products. Despite this, several previous international surveys reported MC in BGA supplements in excess of 1 μg/g. The objectives of this study were (1) identify a reliable, easy to use test kit for the detection of MC in dried BGA materials and (2) use this kit to assess the occurrence of MC contamination in AFA-BGA dietary supplements in the U.S. A commercial protein phosphatase inhibition assay (PPIA), based on the enzyme PP2A, was found to have acceptable relative enzyme inhibition and accuracy for the majority of MC variants tested, including those most commonly identified in commercial samples, making the kit fit for purpose. Using the PPIA kit, 51% (26 of 51) distinct AFA-BGA products had MC ≥0.25 μg/g (the detection limit of the kit), 10 products had MC concentrations between 0.5 and 1.0 μg/g, and 4 products exceeded the limit (1.1–2.8 μg/g). LC-MS/MS confirmed PPIA results ≥0.5 μg/g and determined that MC-LA and MC-LR were the main congeners present. PPIA is a reliable method for the detection of MC contamination in dried BGA dietary supplements produced in the U.S. While the majority of AFA-BGA products contained ≥0.25 μg/g MC, most were at or below 1.0 μg/g, suggesting that manufacturers have adopted this level as a specification in these products; however, variability in recommended serving sizes prevented further analysis of consumer exposure based on the concentrations of MC contamination found.
Collapse
|
46
|
Microcystins: Synthesis and structure–activity relationship studies toward PP1 and PP2A. Bioorg Med Chem 2018; 26:1118-1126. [DOI: 10.1016/j.bmc.2017.08.040] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 08/19/2017] [Accepted: 08/23/2017] [Indexed: 11/19/2022]
|
47
|
Airo AM, Urbanowski MD, Lopez-Orozco J, You JH, Skene-Arnold TD, Holmes C, Yamshchikov V, Malik-Soni N, Frappier L, Hobman TC. Expression of flavivirus capsids enhance the cellular environment for viral replication by activating Akt-signalling pathways. Virology 2018; 516:147-157. [PMID: 29358114 DOI: 10.1016/j.virol.2018.01.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 01/04/2018] [Accepted: 01/09/2018] [Indexed: 01/23/2023]
Abstract
Flaviviruses depend on multiple host pathways during their life cycles and have evolved strategies to avoid the innate immune response. Previously, we showed that the West Nile virus capsid protein plays a role in this process by blocking apoptosis. In this study, we examined how expression of capsid proteins from several flaviviruses affects apoptosis and other host processes that impact virus replication. All of the tested capsid proteins protected cells from Fas-dependent apoptosis through a mechanism that requires activated Akt. Capsid expression upregulated other Akt-dependent cellular processes including expression of glucose transporter 1 and mitochondrial metabolism. Protein phosphatase 1, which is known to inactivate Akt, was identified as a DENV capsid interacting protein. This suggests that DENV capsid expression activates Akt by sequestering phosphatases that downregulate phospho-Akt. Capsid-dependent upregulation of Akt would enhance downstream signalling pathways that affect cell survival and metabolism, thus providing a favourable environment for virus replication.
Collapse
Affiliation(s)
- Adriana M Airo
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Canada
| | | | | | - Jae Hwan You
- Department of Cell Biology, University of Alberta, Edmonton, Canada
| | | | - Charles Holmes
- Department of Biochemistry, University of Alberta, Edmonton, Canada
| | | | - Natasha Malik-Soni
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Lori Frappier
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Tom C Hobman
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Canada; Department of Cell Biology, University of Alberta, Edmonton, Canada; Li Ka Shing Institute of Virology, University of Alberta, Canada; Women & Children's Health Research Institute, University of Alberta, Canada.
| |
Collapse
|
48
|
Abstract
Cysteine thiols are involved in a diverse set of biological transformations, including nucleophilic and redox catalysis, metal coordination and formation of both dynamic and structural disulfides. Often posttranslationally modified, cysteines are also frequently alkylated by electrophilic compounds, including electrophilic metabolites, drugs, and natural products, and are attractive sites for covalent probe and drug development. Quantitative proteomics combined with activity-based protein profiling has been applied to annotate cysteine reactivity, susceptibility to posttranslational modifications, and accessibility to chemical probes, uncovering thousands of functional and small-molecule targetable cysteines across a diverse set of proteins, proteome-wide in an unbiased manner. Reactive cysteines have been targeted by high-throughput screening and fragment-based ligand discovery efforts. New cysteine-reactive electrophiles and compound libraries have been synthesized to enable inhibitor discovery broadly and to minimize nonspecific toxicity and off-target activity of compounds. With the recent blockbuster success of several covalent inhibitors, and the development of new chemical proteomic strategies to broadly identify reactive, ligandable and posttranslationally modified cysteines, cysteine profiling is poised to enable the development of new potent and selective chemical probes and even, in some cases, new drugs.
Collapse
|
49
|
Foss AJ, Butt J, Fuller S, Cieslik K, Aubel MT, Wertz T. Nodularin from benthic freshwater periphyton and implications for trophic transfer. Toxicon 2017; 140:45-59. [PMID: 29107081 DOI: 10.1016/j.toxicon.2017.10.023] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 09/27/2017] [Accepted: 10/23/2017] [Indexed: 10/18/2022]
Abstract
In 2013 and 2015, the Pennsylvania Department of Environmental Protection conducted a survey of lotic habitats within the Susquehanna, Delaware, and Ohio River basins in Pennsylvania, USA, to screen for microcystins/nodularins (MCs/NODs) in algae communities and smallmouth bass (Micropterus dolomieu). Periphyton (68 from 41 sites), juvenile whole fish (153 from 19 sites) and adult fish liver (115 from 16 sites) samples were collected and screened using an Adda enzyme-linked immunosorbent assay (ELISA). Samples that were positive for MCs/NODs were further analyzed using LC-MS/MS, including 14 variants of microcystin and NOD-R and the MMPB technique. The ELISA was positive for 47% of the periphyton collections, with NOD-R confirmed (0.7-82.2 ng g-1 d.w.) in 20 samples. NOD-R was confirmed in 10 of 15 positive juvenile whole fish samples (0.8-16.7 ng g-1 w.w.) and in 2 of 8 liver samples (1.7 & 2.8 ng g-1 w.w.). The MMPB method resulted in total MCs/NODs measured in periphyton (2.2-1269 ng g-1 d.w.), juvenile whole fish (5.0-210 ng g-1 d.w.) and adult livers (8.5-29.5 ng g-1 d.w.). This work illustrates that NOD-R is present in freshwater benthic algae in the USA, which has broader implications for monitoring and trophic transfer.
Collapse
Affiliation(s)
- Amanda J Foss
- GreenWater Laboratories/CyanoLab, 205 Zeagler Drive, Palatka, FL 32177, USA(1).
| | - Jeffery Butt
- Pennsylvania Department of Environmental Protection, Bureau of Clean Water, Rachel Carson State Office Building, 400 Market Street Harrisburg, PA 17101, USA.
| | - Sarah Fuller
- GreenWater Laboratories/CyanoLab, 205 Zeagler Drive, Palatka, FL 32177, USA(1)
| | - Kamil Cieslik
- GreenWater Laboratories/CyanoLab, 205 Zeagler Drive, Palatka, FL 32177, USA(1)
| | - Mark T Aubel
- GreenWater Laboratories/CyanoLab, 205 Zeagler Drive, Palatka, FL 32177, USA(1)
| | - Tim Wertz
- Pennsylvania Department of Environmental Protection, Bureau of Clean Water, Rachel Carson State Office Building, 400 Market Street Harrisburg, PA 17101, USA
| |
Collapse
|
50
|
Mello FD, Braidy N, Marçal H, Guillemin G, Nabavi SM, Neilan BA. Mechanisms and Effects Posed by Neurotoxic Products of Cyanobacteria/Microbial Eukaryotes/Dinoflagellates in Algae Blooms: a Review. Neurotox Res 2017; 33:153-167. [PMID: 28836116 DOI: 10.1007/s12640-017-9780-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 06/28/2017] [Accepted: 07/05/2017] [Indexed: 12/12/2022]
Abstract
Environmental toxins produced by cyanobacteria and dinoflagellates have increasingly become a public health concern due to their ability to damage several tissues in humans. In particular, emerging evidence has called attention to the neurodegenerative effects of the cyanobacterial toxin β-N-methylamino-L-alanine (BMAA). Furthermore, other toxins such as anatoxin, saxitoxin, microcystin, nodularin and ciguatoxin also have a different range of effects on human tissues, including hepatotoxicity, neurotoxicity and gastrointestinal irritation. However, the vast majority of known environmental toxins have not yet been examined in the context of neurodegenerative disease. This review aims to investigate whether neurotoxic mechanisms can be demonstrated in all aforementioned toxins, and whether there exists a link to neurodegeneration. Management of toxin exposure and potential neuroprotective compounds is also discussed. Collectively, all aforementioned microbial toxins are likely to exert some form of neuronal damage, with many of their modes of action consistent with neurodegeneration. This is important in advancing our current understanding of the cytotoxic potential of environmental toxins upon human brain function, particularly in the context of age-related neurodegenerative disease.
Collapse
Affiliation(s)
- Fiona D Mello
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Nady Braidy
- Centre for Healthy Brain Ageing, School of Psychiatry, Faculty of Medicine, The University of New South Wales, Sydney, Australia
| | - Helder Marçal
- Graduate School of Biomedical Engineering, Faculty of Engineering, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Gilles Guillemin
- Neuropharmacology group, MND and Neurodegenerative diseases Research Centre, Macquarie University, Sydney, NSW, Australia
| | - Seyed Mohammad Nabavi
- Applied Biotechnology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Brett A Neilan
- School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW, 2308, Australia.
| |
Collapse
|