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Hidayat AS, Pitt JA, Fredricks H, Hahn ME, Aluru N. Domoic acid induces developmental stage-specific effects on microglia in zebrafish. HARMFUL ALGAE 2025; 146:102862. [PMID: 40409865 PMCID: PMC12102529 DOI: 10.1016/j.hal.2025.102862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/13/2024] [Revised: 04/09/2025] [Accepted: 04/11/2025] [Indexed: 05/25/2025]
Abstract
Harmful algal blooms (HABs), driven by warming oceans and increased eutrophication, are negatively affecting aquatic ecosystems as well as human health. Blooms of diatom Pseudo-nitzschia spp. produce a neurotoxin, domoic acid (DA), which can be concentrated by filter feeders, including shellfish. Consumption of DA-contaminated seafood causes amnesic shellfish poisoning. DA causes well-established effects on neurons, inducing neurotoxicity by binding to ionotropic glutamate receptors. However, its effects on non-neuronal cells including microglia, the resident immune cells in the brain, are less well understood. Microglia play critical roles in brain health, and disruptions in microglial activity during development can have long-term impacts on brain function and disease risk. The objective of this study was to examine the effects of developmental DA exposure on microglia using zebrafish (Danio rerio). We characterized effects of DA exposure on microglial abundance and morphology at two developmental stages (2 and 4 days post-fertilization (dpf)). We additionally assessed impacts on cell death, cytokine expression, and startle response behavior. In older larvae (4 dpf), microglial effects occurred only at the highest dose (0.3 ng DA per larvae) and coincided with severe morphological defects. In contrast, 2 dpf exposure to lower doses (0.1 ng DA per embryo) caused transient tremors without gross abnormalities but exposure to either 0.1 or 0.3 ng DA per larvae increased microglial abundance and altered microglial morphology. In contrast, 4 dpf exposure to 0.3 ng DA per larvae reduced microglial numbers. Increases in mRNA levels of il1b, il4, and tgfb were observed after 4 dpf exposure, but no significant cytokine changes were detected at 2 dpf. Overall, the effects of DA are highly developmental stage-specific, with microglial reactivity occurring at doses that do not cause gross morphological changes. These findings suggest that neuroinflammation may arise at lower DA doses, indicating a potential mechanism for subtle toxic effects and emphasizing the need for further research to better understand the consequences of low-dose DA exposure on microglial function.
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Affiliation(s)
- Alia S Hidayat
- Biology Department and Woods Hole Center for Oceans and Human Health, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA; Massachusetts Institute of Technology (MIT) - Woods Hole Oceanographic Institution (WHOI) Joint Graduate Program in Oceanography and Oceanographic Engineering, USA; Center for American Progress, WA, DC 20002, USA.
| | - Jordan A Pitt
- Biology Department and Woods Hole Center for Oceans and Human Health, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA; Massachusetts Institute of Technology (MIT) - Woods Hole Oceanographic Institution (WHOI) Joint Graduate Program in Oceanography and Oceanographic Engineering, USA; Exponent Inc, 1075 Worcester Street, Natick, MA, 01760, USA
| | - Helen Fredricks
- Marine Chemistry and Geochemistry department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
| | - Mark E Hahn
- Biology Department and Woods Hole Center for Oceans and Human Health, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
| | - Neelakanteswar Aluru
- Biology Department and Woods Hole Center for Oceans and Human Health, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
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2
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Joshi A, Lehene S, Mishra A. Non-transgenic rodent models of Alzheimer's disease for preclinical research: a review. Mol Biol Rep 2025; 52:456. [PMID: 40366433 DOI: 10.1007/s11033-025-10549-5] [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: 02/03/2025] [Accepted: 04/25/2025] [Indexed: 05/15/2025]
Abstract
Alzheimer's disease (AD) is a prevalent neurodegenerative disorder characterized by progressive memory loss and cognitive decline. It involves the irreversible destruction of higher brain structures, leading to significant cognitive deficits, personality changes, and aberrant behavior. Key pathological features include the accumulation of amyloid-beta (Aβ) plaques and hyperphosphorylated tau protein neurofibrillary tangles, which disrupt cellular communication and neuron function. Chronic inflammation, vascular abnormalities, and genetic factors like the APOE (apolipoprotein E) ε4 allele also play crucial roles in AD progression. Epidemiological data indicate a substantial global impact, especially among older adults, with women disproportionately affected. Animal models, both transgenic and non-transgenic, are pivotal in researching AD pathophysiology and potential treatments. This review presents a full overview regarding a variety of non-transgenic rodent models of Alzheimer's disease utilized in the preclinical research for treatment approaches in Alzheimer's disease.
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Affiliation(s)
- Abhishek Joshi
- Department of Pharmacology, Dr. Chunibhai Vallabbhai Patel College of Pharmacy, Uka Tarsadia University, Maliba Campus, Bardoli, Gujarat, India.
| | | | - Ashish Mishra
- Department of Pharmaceutics, Dr. Chunibhai Vallabbhai Patel College of Pharmacy, Uka Tarsadia University, Maliba Campus, Bardoli, Gujarat, India
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3
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Campbell MA, Murphy SR, Klasing SA, Niknam Y, Iyer P, Stanton B, Zeise L. Life Course Considerations in Environmental Health: Developmental Neurotoxicity of Domoic Acid at Doses Below Acute Effect Levels in Adult Humans. Birth Defects Res 2024; 116:e2419. [PMID: 39670542 PMCID: PMC11639046 DOI: 10.1002/bdr2.2419] [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: 07/06/2024] [Revised: 11/08/2024] [Accepted: 11/14/2024] [Indexed: 12/14/2024]
Abstract
BACKGROUND Current US federal action levels for domoic acid (DA) in seafood are based on acute toxicity observed in exposed adult humans. Life course considerations have not been incorporated. The potential for developmental neurotoxicity (DNT) at permissible DA levels has previously been noted, but not methodically assessed. METHODS Studies of DNT following DA exposure in experimental and wild animals were identified through a comprehensive search strategy. Evidence from papers meeting inclusion criteria was evaluated for specific outcomes reported for doses at which adverse effects were observed. Exposure levels associated with DNT were compared with those known to cause adult toxicity. The findings are discussed in the context of the well-characterized mechanism of DA neurotoxicity, as well as the toxicokinetics of DA across species and life stages. CONCLUSIONS DNT outcomes were reported with a no observed adverse effect level (NOAEL) 10 times lower than the NOAEL of 0.75 mg DA/kg for acute effects in adults. Apart from reviewing current regulatory action levels, public health outreach messaging to health care professionals and sensitive populations, such as pregnant or breastfeeding women, should be considered as a means of increasing awareness about risk for DNT from consumption of potentially DA-contaminated seafood.
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Affiliation(s)
- Marlissa A. Campbell
- Office of Environmental Health Hazard Assessment, California Environmental Protection AgencySacramentoCaliforniaUSA
| | - Shannon R. Murphy
- Office of Environmental Health Hazard Assessment, California Environmental Protection AgencySacramentoCaliforniaUSA
| | - Susan A. Klasing
- Office of Environmental Health Hazard Assessment, California Environmental Protection AgencySacramentoCaliforniaUSA
| | - Yassaman Niknam
- Office of Environmental Health Hazard Assessment, California Environmental Protection AgencySacramentoCaliforniaUSA
| | - Poorni Iyer
- Office of Environmental Health Hazard Assessment, California Environmental Protection AgencySacramentoCaliforniaUSA
| | - Beckye Stanton
- Office of Environmental Health Hazard Assessment, California Environmental Protection AgencySacramentoCaliforniaUSA
| | - Lauren Zeise
- Office of Environmental Health Hazard Assessment, California Environmental Protection AgencySacramentoCaliforniaUSA
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Aluru N, Chapman DP, W Becker K, Van Mooy BAS, Karchner SI, Stegeman JJ, Hahn ME. Developmental exposure of zebrafish to saxitoxin causes altered expression of genes associated with axonal growth. Neurotoxicology 2024; 105:303-312. [PMID: 39571800 PMCID: PMC11645194 DOI: 10.1016/j.neuro.2024.11.003] [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: 06/24/2024] [Revised: 09/19/2024] [Accepted: 11/14/2024] [Indexed: 11/24/2024]
Abstract
Saxitoxin (STX) is a potent neurotoxin naturally produced by dinoflagellates and cyanobacteria. STX inhibits voltage-gated sodium channels (VGSCs), affecting the propagation of action potentials. Consumption of seafood contaminated with STX is responsible for paralytic shellfish poisoning (PSP). Humans are among the species most sensitive to PSP; neurological symptoms of exposure range from tingling of the extremities to severe paralysis. The objective of this study was to determine the effects of STX exposure on developmental processes during early embryogenesis. This study was designed to test the hypothesis that early developmental exposure to STX would disrupt key processes, particularly those related to neural development. Zebrafish embryos were exposed to STX (24 or 48 pg) or vehicle (0.3 mM HCl) at 6 h post fertilization (hpf) via microinjection. There was no overt toxicity but starting at 36 hpf there was a temporary lack of pigmentation in STX-injected embryos, which resolved by 72 hpf. Using high performance liquid chromatography, we found that STX was retained in embryos up to 72 hpf in a dose-dependent manner. Temporal transcriptional profiling of embryos exposed to 48 pg STX per embryo revealed no differentially expressed genes (DEGs) at 24 hpf, but at 36 and 48 hpf, there were 3547 and 3356 DEGs, respectively. KEGG pathway analysis revealed significant enrichment of genes related to focal adhesion, adherens junction and regulation of actin cytoskeleton, suggesting that cell-cell and cell-extracellular matrix interactions were affected by STX. Genes affected are critical for axonal growth and the development of functional neural networks. We confirmed these findings by visualizing axonal defects in transgenic zebrafish with fluorescently labeled sensory neurons. In addition, our gene expression results suggest that STX exposure affects both canonical and noncanonical functions of VGSCs. Given the fundamental role of VGSCs in both physiology and development, these findings offer valuable insights into effects of exposure to neurotoxins.
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Affiliation(s)
- Neelakanteswar Aluru
- Biology Department and Center for Oceans and Human Health,Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA.
| | - Daniel P Chapman
- Biology Department and Center for Oceans and Human Health,Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA; Eckerd College, 4200 54th Ave S, St. Petersburg, FL 33711, USA; Georgetown University School of Medicine, 3970 Reservoir Road NW, Washington DC 20057, USA
| | - Kevin W Becker
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA; GEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstr. 1-3, Kiel 24148, Germany
| | - Benjamin A S Van Mooy
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA
| | - Sibel I Karchner
- Biology Department and Center for Oceans and Human Health,Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA
| | - John J Stegeman
- Biology Department and Center for Oceans and Human Health,Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA
| | - Mark E Hahn
- Biology Department and Center for Oceans and Human Health,Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA
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Sivaprakasam P, Chandrabose K, Pandurangan AK. In-vivo Toxicity Evaluation of 3-(2-(3,4 dimethoxyphenyl)-2 oxoethylidene) Indolin-2-one (RAJI) in Zebrafish and Mice Model. Asian Pac J Cancer Prev 2024; 25:3159-3172. [PMID: 39342595 DOI: 10.31557/apjcp.2024.25.9.3159] [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: 04/17/2024] [Indexed: 10/01/2024] Open
Abstract
OBJECTIVE Breast cancer is a global health concern, with millions of cases reported annually worldwide, making it the most common cancer among women. In India, the incidence of breast cancer has been steadily rising, reflecting a growing public health challenge and hence in the development of new drug moieties. Toxicity analysis of such novel drug candidates play a critical role in drug development, ensuring the safety and efficacy of potential therapeutics. Animal models, especially mice and zebrafish in the recent days, have been extensively used for toxicity evaluation owing to their physiological and genetic similarities to humans. This study was hence conducted with an aim to assess the toxicity using animal models, particularly mice and zebrafish. METHODS In this study, 3-(2-(3,4-dimethoxyphenyl)-2-oxoethylidene)indolin-2-one (RAJI) - a chemically synthesised novel drug, was assessed for its toxicological potential in both zebrafish and mice models highlighting its survival, hatching, locomotor, neuromotor, behavioural abnormalities in zebrafish model and haematological and biochemical abnormalities in mice model. RESULTS The results obtained emphasise that no significant damages were seen in both zebrafish (survival, hatching, locomotor, neuromotor, behavioural abnormalities) and mice (body weight, haematological and biochemical abnormalities) models when administered in low doses. CONCLUSION All results obtained signifies that RAJI poses no harmful effects in the model organisms until administered in higher concentrations, thereby emphasising the fact that RAJI is a safe drug.
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Affiliation(s)
- Prathibha Sivaprakasam
- School of Life Sciences, B. S. Abdur Rahman Crescent Institute of Science and Technology, Vandalur, Chennai, India
| | | | - Ashok Kumar Pandurangan
- School of Life Sciences, B. S. Abdur Rahman Crescent Institute of Science and Technology, Vandalur, Chennai, India
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6
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Mastin N, Durell L, Brooks BW, Hering AS. Advancing statistical treatment of photolocomotor behavioral response study data. PLoS One 2024; 19:e0300636. [PMID: 38771799 PMCID: PMC11108188 DOI: 10.1371/journal.pone.0300636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 03/02/2024] [Indexed: 05/23/2024] Open
Abstract
Fish photolocomotor behavioral response (PBR) studies have become increasingly prevalent in pharmacological and toxicological research to assess the environmental impact of various chemicals. There is a need for a standard, reliable statistical method to analyze PBR data. The most common method currently used, univariate analysis of variance (ANOVA), does not account for temporal dependence in observations and leads to incomplete or unreliable conclusions. Repeated measures ANOVA, another commonly used method, has drawbacks in its interpretability for PBR study data. Because each observation is collected continuously over time, we instead consider each observation to be a function and apply functional ANOVA (FANOVA) to PBR data. Using the functional approach not only accounts for temporal dependency but also retains the full structure of the data and allows for straightforward interpretation in any subregion of the domain. Unlike the traditional univariate and repeated measures ANOVA, the FANOVA that we propose is nonparametric, requiring minimal assumptions. We demonstrate the disadvantages of univariate and repeated measures ANOVA using simulated data and show how they are overcome by applying FANOVA. We then apply one-way FANOVA to zebrafish data from a PBR study and discuss how those results can be reproduced for future PBR studies.
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Affiliation(s)
- Natalie Mastin
- Department of Statistical Science, Baylor University, Waco, TX, United States of America
| | - Luke Durell
- Department of Statistical Science, Baylor University, Waco, TX, United States of America
| | - Bryan W. Brooks
- Department of Environmental Science, Baylor University, Waco, TX, United States of America
- Institute of Biomedical Studies, Baylor University, Waco, TX, United States of America
| | - Amanda S. Hering
- Department of Statistical Science, Baylor University, Waco, TX, United States of America
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7
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De la Paz JF, Zambrano NO, Ortiz FC, Llanos-Rivera A. A New Bioassay for the Detection of Paralytic and Amnesic Biotoxins Based on Motor Behavior Impairments of Zebrafish Larvae. Int J Mol Sci 2023; 24:ijms24087466. [PMID: 37108629 PMCID: PMC10144378 DOI: 10.3390/ijms24087466] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 04/05/2023] [Accepted: 04/11/2023] [Indexed: 04/29/2023] Open
Abstract
The global concern about the increase of harmful algal bloom events and the possible impacts on food safety and aquatic ecosystems presents the necessity for the development of more accessible techniques for biotoxin detection for screening purposes. Considering the numerous advantages that zebrafish present as a biological model and particularly as a toxicants sentinel, we designed a sensitive and accessible test to determine the activity of paralytic and amnesic biotoxins using zebrafish larvae immersion. The ZebraBioTox bioassay is based on the automated recording of larval locomotor activity using an IR microbeam locomotion detector, and manual assessment of four complementary responses under a simple stereoscope: survival, periocular edema, body balance, and touch response. This 24 h acute static bioassay was set up in 96-well microplates using 5 dpf zebrafish larvae. For paralytic toxins, a significant decrease in locomotor activity and touch response of the larvae was detected, allowing a detection threshold of 0.1-0.2 µg/mL STXeq. In the case of the amnesic toxin the effect was reversed, detecting hyperactivity with a detection threshold of 10 µg/mL domoic acid. We propose that this assay might be used as a complementary tool for environmental safety monitoring.
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Affiliation(s)
- Javiera F De la Paz
- Laboratorio de Embriotoxicología e Interacción Desarrollo Ambiente (LEIDA), Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción 4070386, Chile
- Laboratorio de Toxicología Acuática, Departamento de Oceanografía, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Concepción 4070386, Chile
- Danio Biotechnologies, SpA, Santiago 8271199, Chile
| | - Nicolás O Zambrano
- Laboratorio de Toxicología Acuática, Departamento de Oceanografía, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Concepción 4070386, Chile
- Danio Biotechnologies, SpA, Santiago 8271199, Chile
| | - Fernando C Ortiz
- Mechanisms of Myelin Formation and Repair Laboratory, Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Av. Alameda 3363, Estación Central, Santiago 9170022, Chile
| | - Alejandra Llanos-Rivera
- Laboratorio de Toxicología Acuática, Departamento de Oceanografía, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Concepción 4070386, Chile
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8
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Panlilio JM, Hammar KM, Aluru N, Hahn ME. Developmental exposure to domoic acid targets reticulospinal neurons and leads to aberrant myelination in the spinal cord. Sci Rep 2023; 13:2587. [PMID: 36788234 PMCID: PMC9929266 DOI: 10.1038/s41598-023-28166-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 01/13/2023] [Indexed: 02/16/2023] Open
Abstract
Harmful algal blooms (HABs) produce neurotoxins that affect human health. Developmental exposure of zebrafish embryos to the HAB toxin domoic acid (DomA) causes myelin defects, loss of reticulospinal neurons, and behavioral deficits. However, it is unclear whether DomA primarily targets myelin sheaths, leading to the loss of reticulospinal neurons, or reticulospinal neurons, causing myelin defects. Here, we show that while exposure to DomA at 2 dpf did not reduce the number of oligodendrocyte precursors prior to myelination, it led to fewer myelinating oligodendrocytes that produced shorter myelin sheaths and aberrantly wrapped neuron cell bodies. DomA-exposed larvae lacked Mauthner neurons prior to the onset of myelination, suggesting that axonal loss is not secondary to myelin defects. The loss of the axonal targets may have led oligodendrocytes to inappropriately myelinate neuronal cell bodies. Consistent with this, GANT61, a GLI1/2 inhibitor that reduces oligodendrocyte number, caused a reduction in aberrantly myelinated neuron cell bodies in DomA-exposed fish. Together, these results suggest that DomA initially alters reticulospinal neurons and the loss of axons causes aberrant myelination of nearby cell bodies. The identification of initial targets and perturbed cellular processes provides a mechanistic understanding of how DomA alters neurodevelopment, leading to structural and behavioral phenotypes.
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Affiliation(s)
- Jennifer M Panlilio
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, USA.
- Massachusetts Institute of Technology (MIT) - Woods Hole Oceanographic Institution (WHOI) Joint Graduate Program in Oceanography and Oceanographic Engineering, Cambridge, USA.
- Woods Hole Center for Oceans and Human Health, Woods Hole, MA, 02543, USA.
| | - Katherine M Hammar
- Central Microscopy Facility, Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA, 02543, USA
| | - Neelakanteswar Aluru
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, USA
- Woods Hole Center for Oceans and Human Health, Woods Hole, MA, 02543, USA
| | - Mark E Hahn
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, USA
- Woods Hole Center for Oceans and Human Health, Woods Hole, MA, 02543, USA
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9
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Paquette E, Mumper N, Rodrigues A, Voulo M, Rich S, Roy NM. Hindbrain defects induced by Di-butyl phthalate (DBP) in developing zebrafish embryos. Neurotoxicol Teratol 2022; 92:107093. [PMID: 35477034 DOI: 10.1016/j.ntt.2022.107093] [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: 03/26/2022] [Revised: 04/17/2022] [Accepted: 04/21/2022] [Indexed: 11/28/2022]
Abstract
Di-butyl phthalate (DBP) is a globally used plasticizer found in alarmingly high concentrations in soil and water ecosystems. As phthalates are non-covalently bound to plastic polymers, phthalates easily leach into the aquatic environment. The effects of DBP on aquatic organisms is concerning, most notably, studies have focused on the endocrine-disrupting effects. However, reports on the developmental neurotoxicity of DBP are rare. Using the zebrafish vertebrate model system, we treated pre-gastrulation staged embryos with 2.5 μM DBP, a concentration environmentally noted. We find that general hindbrain structure and rhombomere patterning is disrupted at 72 h post fertilization (hpf). We investigated hindbrain specific neural patterning of cranial motor neurons and find defects in branchiomotor neuron patterning and migration. Furthermore, defects in r4 specific Mauthner neuron development were also noted. Thus, we conclude that DBP exposure during embryonic development induces defects to the hindbrain and concomitantly the neurons that are born and differentiate there.
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Affiliation(s)
- Evelyn Paquette
- Department of Biology, Sacred Heart University, Fairfield, CT, United States of America
| | - Naomi Mumper
- Department of Biology, Sacred Heart University, Fairfield, CT, United States of America
| | - Alissa Rodrigues
- Department of Biology, Sacred Heart University, Fairfield, CT, United States of America
| | - Morgan Voulo
- Department of Biology, Sacred Heart University, Fairfield, CT, United States of America
| | - Sierrah Rich
- Department of Biology, Sacred Heart University, Fairfield, CT, United States of America
| | - Nicole M Roy
- Department of Biology, Sacred Heart University, Fairfield, CT, United States of America.
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10
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Brun NR, Salanga MC, Mora-Zamorano FX, Lamb DC, Goldstone JV, Stegeman JJ. Orphan cytochrome P450 20a1 CRISPR/Cas9 mutants and neurobehavioral phenotypes in zebrafish. Sci Rep 2021; 11:23892. [PMID: 34903767 PMCID: PMC8669017 DOI: 10.1038/s41598-021-03068-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Accepted: 11/19/2021] [Indexed: 11/08/2022] Open
Abstract
Orphan cytochrome P450 (CYP) enzymes are those for which biological substrates and function(s) are unknown. Cytochrome P450 20A1 (CYP20A1) is the last human orphan P450 enzyme, and orthologs occur as single genes in every vertebrate genome sequenced to date. The occurrence of high levels of CYP20A1 transcripts in human substantia nigra and hippocampus and abundant maternal transcripts in zebrafish eggs strongly suggest roles both in the brain and during early embryonic development. Patients with chromosome 2 microdeletions including CYP20A1 show hyperactivity and bouts of anxiety, among other conditions. Here, we created zebrafish cyp20a1 mutants using CRISPR/Cas9, providing vertebrate models with which to study the role of CYP20A1 in behavior and other neurodevelopmental functions. The homozygous cyp20a1 null mutants exhibited significant behavioral differences from wild-type zebrafish, both in larval and adult animals. Larval cyp20a1-/- mutants exhibited a strong increase in light-simulated movement (i.e., light-dark assay), which was interpreted as hyperactivity. Further, the larvae exhibited mild hypoactivity during the adaptation period of the optomotor assays. Adult cyp20a1 null fish showed a pronounced delay in adapting to new environments, which is consistent with an anxiety paradigm. Taken together with our earlier morpholino cyp20a1 knockdown results, the results described herein suggest that the orphan CYP20A1 has a neurophysiological role.
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Affiliation(s)
- Nadja R Brun
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, USA
| | - Matthew C Salanga
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | | | - David C Lamb
- Faculty of Medicine, Health and Life Sciences, Swansea University, Swansea, SA2 8PP, UK
| | - Jared V Goldstone
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, USA
| | - John J Stegeman
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, USA.
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11
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Brun NR, Panlilio JM, Zhang K, Zhao Y, Ivashkin E, Stegeman JJ, Goldstone JV. Developmental exposure to non-dioxin-like polychlorinated biphenyls promotes sensory deficits and disrupts dopaminergic and GABAergic signaling in zebrafish. Commun Biol 2021; 4:1129. [PMID: 34561524 PMCID: PMC8463681 DOI: 10.1038/s42003-021-02626-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 08/25/2021] [Indexed: 11/09/2022] Open
Abstract
The most abundant polychlorinated biphenyl (PCB) congeners found in the environment and in humans are neurotoxic. This is of particular concern for early life stages because the exposure of the more vulnerable developing nervous system to neurotoxic chemicals can result in neurobehavioral disorders. In this study, we uncover currently unknown links between PCB target mechanisms and neurobehavioral deficits using zebrafish as a vertebrate model. We investigated the effects of the abundant non-dioxin-like (NDL) congener PCB153 on neuronal morphology and synaptic transmission linked to the proper execution of a sensorimotor response. Zebrafish that were exposed during development to concentrations similar to those found in human cord blood and PCB contaminated sites showed a delay in startle response. Morphological and biochemical data demonstrate that even though PCB153-induced swelling of afferent sensory neurons, the disruption of dopaminergic and GABAergic signaling appears to contribute to PCB-induced motor deficits. A similar delay was observed for other NDL congeners but not for the potent dioxin-like congener PCB126. The effects on important and broadly conserved signaling mechanisms in vertebrates suggest that NDL PCBs may contribute to neurodevelopmental abnormalities in humans and increased selection pressures in vertebrate wildlife.
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Affiliation(s)
- Nadja R Brun
- Department of Biology, Woods Hole Oceanographic Institution, Woods Hole, MA, USA.
| | - Jennifer M Panlilio
- Department of Biology, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - Kun Zhang
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.,Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China
| | - Yanbin Zhao
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.,Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China
| | - Evgeny Ivashkin
- Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, Marine Biological Laboratory, Woods Hole, MA, USA.,A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia
| | - John J Stegeman
- Department of Biology, Woods Hole Oceanographic Institution, Woods Hole, MA, USA.
| | - Jared V Goldstone
- Department of Biology, Woods Hole Oceanographic Institution, Woods Hole, MA, USA.
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