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Wang Z, Yang L, Zhou F, Li J, Wu X, Zhong X, Lv H, Yi S, Gao Q, Yang Z, Zhao P, Wu Y, Wu C, Zhang L, Wang H, Zhang L. Integrated comparative transcriptome and weighted gene co-expression network analysis provide valuable insights into the response mechanisms of crayfish (Procambarus clarkii) to copper stress. JOURNAL OF HAZARDOUS MATERIALS 2023; 448:130820. [PMID: 36860031 DOI: 10.1016/j.jhazmat.2023.130820] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Revised: 01/15/2023] [Accepted: 01/16/2023] [Indexed: 06/18/2023]
Abstract
One of the significant limitations of aquaculture worldwide is the prevalence of divalent copper (Cu). Crayfish (Procambarus clarkii) are economically important freshwater species adapted to a variety of environmental stimuli, including heavy metal stresses; however, large-scale transcriptomic data of the hepatopancreas of crayfish in response to Cu stress are still scarce. Here, integrated comparative transcriptome and weighted gene co-expression network analyses were initially applied to investigate gene expression profiles of the hepatopancreas of crayfish subjected to Cu stress for different periods. As a result, 4662 significant differentially expressed genes (DEGs) were identified following Cu stress. Bioinformatics analyses revealed that the "focal adhesion" pathway was one of the most significantly upregulated response pathways following Cu stress, and seven DEGs mapped to this pathway were identified as hub genes. Furthermore, the seven hub genes were examined by quantitative PCR, and each was found to have a substantial increase in transcript abundance, suggesting a critical role of the "focal adhesion" pathway in the response of crayfish to Cu stress. Our transcriptomic data can be a good resource for the functional transcriptomics of crayfish, and these results may provide valuable insights into the molecular response mechanisms underlying crayfish to Cu stress.
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Affiliation(s)
- Zhanqi Wang
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, College of Life Sciences, Huzhou University, Huzhou 313000, China.
| | - Lianlian Yang
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, College of Life Sciences, Huzhou University, Huzhou 313000, China
| | - Fan Zhou
- Zhejiang Fisheries Technical Extension Center, Hangzhou 310023, China
| | - Jiapeng Li
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, College of Life Sciences, Huzhou University, Huzhou 313000, China
| | - Xiaoyin Wu
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, College of Life Sciences, Huzhou University, Huzhou 313000, China
| | - Xueting Zhong
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, College of Life Sciences, Huzhou University, Huzhou 313000, China
| | - He Lv
- Zhejiang Provincial Key Laboratory of Aquatic Resources Conservation and Development, College of Life Sciences, Huzhou University, Huzhou 313000, China
| | - Shaokui Yi
- Zhejiang Provincial Key Laboratory of Aquatic Resources Conservation and Development, College of Life Sciences, Huzhou University, Huzhou 313000, China
| | - Quanxin Gao
- Zhejiang Provincial Key Laboratory of Aquatic Resources Conservation and Development, College of Life Sciences, Huzhou University, Huzhou 313000, China
| | - Zi Yang
- Department of Ecology, College of Life Sciences, Henan Normal University, Xinxiang 453007, China
| | - Pengfei Zhao
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, College of Life Sciences, Huzhou University, Huzhou 313000, China
| | - Yi Wu
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, College of Life Sciences, Huzhou University, Huzhou 313000, China
| | - Choufei Wu
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, College of Life Sciences, Huzhou University, Huzhou 313000, China
| | - Liqin Zhang
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, College of Life Sciences, Huzhou University, Huzhou 313000, China
| | - Hua Wang
- Huzhou Key Laboratory of Medical and Environmental Application Technologies, College of Life Sciences, Huzhou University, Huzhou 313000, China.
| | - Lixia Zhang
- Department of Ecology, College of Life Sciences, Henan Normal University, Xinxiang 453007, China.
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Ma Y, He J, Sieber M, von Frieling J, Bruchhaus I, Baines JF, Bickmeyer U, Roeder T. The microbiome of the marine flatworm Macrostomum lignano provides fitness advantages and exhibits circadian rhythmicity. Commun Biol 2023; 6:289. [PMID: 36934156 PMCID: PMC10024726 DOI: 10.1038/s42003-023-04671-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 03/07/2023] [Indexed: 03/20/2023] Open
Abstract
The close association between animals and their associated microbiota is usually beneficial for both partners. Here, we used a simple marine model invertebrate, the flatworm Macrostomum lignano, to characterize the host-microbiota interaction in detail. This analysis revealed that the different developmental stages each harbor a specific microbiota. Studies with gnotobiotic animals clarified the physiological significance of the microbiota. While no fitness benefits were mediated by the microbiota when food was freely available, animals with microbiota showed significantly increased fitness with a reduced food supply. The microbiota of M. lignano shows circadian rhythmicity, affecting both the total bacterial load and the behavior of specific taxa. Moreover, the presence of the worm influences the composition of the bacterial consortia in the environment. In summary, the Macrostomum-microbiota system described here can serve as a general model for host-microbe interactions in marine invertebrates.
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Affiliation(s)
- Yuanyuan Ma
- Kiel University, Zoological Institute, Molecular Physiology, Kiel, Germany
| | - Jinru He
- Kiel University, Zoological Institute, Cell and Developmental Biology, Kiel, Germany
| | - Michael Sieber
- Max-Planck Institute for Evolutionary Biology, Dept. Evolutionary Theory, Plön, Germany
| | - Jakob von Frieling
- Kiel University, Zoological Institute, Molecular Physiology, Kiel, Germany
| | - Iris Bruchhaus
- Bernhard-Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - John F Baines
- Kiel University, Medical Faculty, Institute for Experimental Medicine, Kiel, Germany
- Max-Planck Institute for Evolutionary Biology, Group Evolutionary Medicine, Plön, Germany
| | - Ulf Bickmeyer
- Alfred-Wegener-Institute, Biosciences, Ecological Chemistry, Bremerhaven, Germany
| | - Thomas Roeder
- Kiel University, Zoological Institute, Molecular Physiology, Kiel, Germany.
- German Center for Lung Research (DZL), Airway Research Center North, Kiel, Germany.
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3
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Anjomshoa M, Sahihi M, Fatemi SJ, Shayegan S, Farsinejad A, Amirheidari B. In vitro biological and in silico molecular docking and ADME studies of a substituted triazine-coordinated cadmium(II) ion: efficient cytotoxicity, apoptosis, genotoxicity, and nuclease-like activity plus binding affinity towards apoptosis-related proteins. Biometals 2022; 35:549-572. [PMID: 35366135 DOI: 10.1007/s10534-022-00387-4] [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: 06/26/2021] [Accepted: 03/07/2022] [Indexed: 12/24/2022]
Abstract
A cadmium(II) complex containing dppt ligand with the formula [CdCl2(dppt)2], where dppt is 5,6-diphenyl-3-(2-pyridyl)-1,2,4-triazine was synthesized, elucidated and submitted to in vitro cytotoxicity studies against human breast (MCF-7), glioblastoma (U-87), and lung (A549) cancer cell lines as well as mouse embryo normal cell line (NIH/3T3), in comparison with cisplatin employing MTT assay over 24 and 48 h. The complex exhibited the highest cytotoxic effect against MCF-7 cells among the other three cell lines with IC50 values of 8.7 ± 0.5 (24 h) and 1.2 ± 0.7 µM (48 h). Significantly, flow cytometric assessment of the complex-treated MCF-7 and U-87 cells demonstrated a dose-dependent induced apoptotic cell death. The cellular morphological changes were in concord with cytotoxicity and flow cytometric results. The results of comet assay showed that the complex is able to induce DNA damage in MCF-7 cells. These observations are of importance, as sustained damage to cellular DNA could lead to apoptotic cell death. The results of DNA-binding studies indicated that the complex fits into the DNA minor groove and interacts with DNA via a partial intercalation. Moreover, the complex was able to efficiently cleave pUC19 DNA through a hydrolytic mechanism. The binding affinity between the complex and apoptosis-relevant protein targets including APAF1, Bax, Bcl-2, Cas3, Cas7, and Cas9 was evaluated through molecular docking studies. In silico virtual studies revealed the complex's strong affinity towards apoptosis-related proteins; therefore the complex can act as a potential apoptosis inducer. Physicochemical, pharmacokinetics, lipophilicity, drug-likeness, and medicinal chemistry properties of the complex were also predicted through in silico absorption, distribution, metabolism and excretion studies.
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Affiliation(s)
- Marzieh Anjomshoa
- Pharmaceutical Sciences and Cosmetic Products Research Center, Kerman University of Medical Sciences, Kerman, Iran.
| | - Mehdi Sahihi
- Roberval Laboratory, Université de Technologie de Compiègne, Alliance Sorbonne Université, Compiègne, France
| | | | - Shika Shayegan
- Department of Pharmacy, Eastern Mediterranean University, TRNC via Mersin 10, Famagusta, Turkey
| | - Alireza Farsinejad
- Cell Therapy and Regenerative Medicine Comprehensive Center, Kerman University of Medical Sciences, Kerman, Iran
| | - Bagher Amirheidari
- Pharmaceutics Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran. .,Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Kerman University of Medical Sciences, Kerman, Iran.
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Aigner GP, Nenning P, Fiechtner B, Šrut M, Höckner M. DNA Methylation and Detoxification in the Earthworm Lumbricus terrestris Exposed to Cadmium and the DNA Demethylation Agent 5-aza-2'-deoxycytidine. TOXICS 2022; 10:100. [PMID: 35202286 PMCID: PMC8879108 DOI: 10.3390/toxics10020100] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 02/14/2022] [Accepted: 02/18/2022] [Indexed: 01/27/2023]
Abstract
Earthworms are well-established model organisms for testing the effects of heavy metal pollution. How DNA methylation affects cadmium (Cd) detoxification processes such as the expression of metallothionein 2 (MT2), however, is largely unknown. We therefore exposed Lumbricus terrestris to 200 mg concentrations of Cd and 5-aza-2'-deoxycytidine (Aza), a demethylating agent, and sampled tissue and coelomocytes, cells of the innate immune system, for 48 h. MT2 transcription significantly increased in the Cd- and Cd-Aza-treated groups. In tissue samples, a significant decrease in MT2 in the Aza-treated group was detected, showing that Aza treatment inhibits basal MT2 gene activity but has no effect on Cd-induced MT2 levels. Although Cd repressed the gene expression of DNA-(cytosine-5)-methyltransferase-1 (DNMT1), which is responsible for maintaining DNA methylation, DNMT activity was unchanged, meaning that methylation maintenance was not affected in coelomocytes. The treatment did not influence DNMT3, which mediates de novo methylation, TET gene expression, which orchestrates demethylation, and global levels of hydroxymethylcytosine (5hmC), a product of the demethylation process. Taken together, this study indicates that Aza inhibits basal gene activity, in contrast to Cd-induced MT2 gene expression, but does not affect global DNA methylation. We therefore conclude that Cd detoxification based on the induction of MT2 does not relate to DNA methylation changes.
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Affiliation(s)
| | | | | | | | - Martina Höckner
- Department of Zoology, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria; (G.P.A.); (P.N.); (B.F.); (M.Š.)
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5
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Looking at Developmental Neurotoxicity Testing from the Perspective of an Invertebrate Embryo. Int J Mol Sci 2022; 23:ijms23031871. [PMID: 35163796 PMCID: PMC8836978 DOI: 10.3390/ijms23031871] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 02/04/2022] [Accepted: 02/05/2022] [Indexed: 02/01/2023] Open
Abstract
Developmental neurotoxicity (DNT) of chemical compounds disrupts the formation of a normal brain. There is impressive progress in the development of alternative testing methods for DNT potential in chemicals, some of which also incorporate invertebrate animals. This review briefly touches upon studies on the genetically tractable model organisms of Caenorhabditis elegans and Drosophila melanogaster about the action of specific developmental neurotoxicants. The formation of a functional nervous system requires precisely timed axonal pathfinding to the correct cellular targets. To address this complex key event, our lab developed an alternative assay using a serum-free culture of intact locust embryos. The first neural pathways in the leg of embryonic locusts are established by a pair of afferent pioneer neurons which use guidance cues from membrane-bound and diffusible semaphorin proteins. In a systematic approach according to recommendations for alternative testing, the embryo assay quantifies defects in pioneer navigation after exposure to a panel of recognized test compounds for DNT. The outcome indicates a high predictability for test-compound classification. Since the pyramidal neurons of the mammalian cortex also use a semaphorin gradient for neurite guidance, the assay is based on evolutionary conserved cellular mechanisms, supporting its relevance for cortical development.
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6
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Liao J, Li Q, Hu Z, Yu W, Zhang K, Ma F, Han Q, Zhang H, Guo J, Hu L, Pan J, Li Y, Tang Z. Mitochondrial miR-1285 regulates copper-induced mitochondrial dysfunction and mitophagy by impairing IDH2 in pig jejunal epithelial cells. JOURNAL OF HAZARDOUS MATERIALS 2022; 422:126899. [PMID: 34418838 DOI: 10.1016/j.jhazmat.2021.126899] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 08/10/2021] [Accepted: 08/11/2021] [Indexed: 06/13/2023]
Abstract
Copper (Cu), a hazardous heavy metal, can lead to toxic effects on host physiology. Recently, specific mitochondria-localized miRNAs (mitomiRs) were shown to modulate mitochondrial function, but the underlying mechanisms remain undefined. Here, we identified mitomiR-1285 as an important molecule regulating mitochondrial dysfunction and mitophagy in jejunal epithelial cells under Cu exposure. Mitochondrial dysfunction and mitophagy were the important mechanisms of Cu-induced pathological damage in jejunal epithelial cells, which were accompanied by significant increase of mitomiR-1285 in vivo and in vitro. Knockdown of mitomiR-1285 significantly attenuated Cu-induced mitochondrial respiratory dysfunction, ATP deficiency, mitochondrial membrane potential reduction, mitochondrial reactive oxygen species accumulation, and mitophagy. Subsequently, bioinformatics analysis and luciferase reporter assay demonstrated that IDH2 was a direct target of mitomiR-1285. RNA interference of IDH2 dramatically reversed the effect that mitomiR-1285 knockdown relieved mitochondrial dysfunction and mitophagy induced by Cu, and the opposite effect was shown by overexpression of IDH2. Therefore, our results suggested that mitomiR-1285 aggravated Cu-induced mitochondrial dysfunction and mitophagy via suppressing IDH2 expression. These findings identified the important mechanistic connection between mitomiRs and mitochondrial metabolism under Cu exposure, providing a new insight into Cu toxicology.
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Affiliation(s)
- Jianzhao Liao
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, Guangdong, PR China
| | - Quanwei Li
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, Guangdong, PR China
| | - Zhuoying Hu
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, Guangdong, PR China
| | - Wenlan Yu
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, Guangdong, PR China
| | - Kai Zhang
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, Guangdong, PR China
| | - Feiyang Ma
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, Guangdong, PR China
| | - Qingyue Han
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, Guangdong, PR China
| | - Hui Zhang
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, Guangdong, PR China
| | - Jianying Guo
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, Guangdong, PR China
| | - Lianmei Hu
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, Guangdong, PR China
| | - Jiaqiang Pan
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, Guangdong, PR China
| | - Ying Li
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, Guangdong, PR China
| | - Zhaoxin Tang
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, Guangdong, PR China.
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7
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Wang Z, Kong F, Fu L, Li Y, Li M, Yu Z. Responses of Asian clams (Corbicula fluminea) to low concentration cadmium stress: Whether the depuration phase restores physiological characteristics. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 284:117182. [PMID: 33901982 DOI: 10.1016/j.envpol.2021.117182] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 03/21/2021] [Accepted: 04/14/2021] [Indexed: 06/12/2023]
Abstract
The effect of low concentration Cd stress on bivalves is unclear. In this study, Asian clams (Corbicula fluminea) were continuously exposed to 0, 0.05, 0.10, and 0.20 mg/L Cd for 14 d (exposure phase) and to artificial freshwater for 7 d (depuration phase). A total of 16 variables were measured to explore the toxic effects on C. fluminea. All physiological characteristics were significantly inhibited in the treatments (p < 0.05), and the negative effects of Cd did not return to normal levels in the short term. Tissue damage was found in the feet and gills of C. fluminea in all the treatments. On the 7th day (D7), enzyme activity in all the treatments was significantly higher (p < 0.05) than in the control group. Acetylcholinesterase, superoxide dismutase, and catalase activities were enhanced on D14 in all the treatments. However, only glutathione S-transferase activity was significantly higher in all the treatments (p < 0.05) than in the control group on D21. The instability of the enzymes indicated that the adaptability of C. fluminea became stronger throughout the experiment. In each group, the maximum bioaccumulation of Cd followed the order: 0.20 mg/L > 0.05 mg/L > 0.10 mg/L, which might be caused by the filtration capacity of C. fluminea in the 0.05-mg/L group, which was higher than that of the 0.10-mg/L group. Thus, low Cd concentrations effect the physiological characteristics, tissue health, and antioxidant system of C. fluminea and may require a long recovery time to be restored to normal levels.
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Affiliation(s)
- Zhen Wang
- College of Environmental Sciences and Engineering, Qingdao University, Qingdao, 266071, China
| | - Fanlong Kong
- College of Environmental Sciences and Engineering, Qingdao University, Qingdao, 266071, China
| | - Lingtao Fu
- College of Environmental Sciences and Engineering, Qingdao University, Qingdao, 266071, China
| | - Yue Li
- College of Environmental Sciences and Engineering, Qingdao University, Qingdao, 266071, China
| | - Minghui Li
- College of Environmental Sciences and Engineering, Qingdao University, Qingdao, 266071, China
| | - Zhengda Yu
- College of Environmental Sciences and Engineering, Qingdao University, Qingdao, 266071, China.
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8
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Hoeltgebaum D, Pedron T, Paniz FP, Souza AA, Romoli JCZ, Lini RS, Pante GC, Rocha GHO, Batista BL, Machinski Junior M. Metals in Brazilian family farming grapes and estimated daily intake. FOOD ADDITIVES & CONTAMINANTS PART B-SURVEILLANCE 2021; 14:236-243. [PMID: 34142923 DOI: 10.1080/19393210.2021.1933612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The aim of this study was to determine concentrations of metals in peel, pulp, and seeds of grapes obtained from family farms in Brazil, compare them to the maximum threshold levels and to evaluate the risk by estimating the daily intake (EDI). Grape samples were collected from farms and levels of Cd, Cr, Cu, Mn, Ni, Pb and Zn were assessed via ICP-MS. The highest metal levels were found in grape peels, Cu at the highest concentration (107.6 mg kg-1). Cr, Cu, and Pb were found at concentrations which exceeded maximum threshold levels. The EDI of Cd, Cu and Pb through consumption of grapes for the assessed Brazilian population was 0.29, 1822 and 3.02 µg/kg bw/day, respectively. The EDI of Cu was above the Provisionary Tolerable Daily Intake (PTDI). Thus, there are possible health risks due to the occurrence of Cu in Brazilian grapes.
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Affiliation(s)
- Danielle Hoeltgebaum
- Post-Graduate Program in Health Sciences, State University of Maringa, Maringa, Brazil
| | - Tatiana Pedron
- Center for Natural and Human Sciences, Federal University of ABC, Santo Andre, Brazil
| | - Fernanda Pollo Paniz
- Center for Natural and Human Sciences, Federal University of ABC, Santo Andre, Brazil
| | - Aline Amenência Souza
- Post-Graduate Program in Health Sciences, State University of Maringa, Maringa, Brazil
| | | | - Renata Sano Lini
- Post-Graduate Program in Biosciences and Physiopathology, State University of Maringa, Maringa, Brazil
| | | | - Gustavo Henrique Oliveira Rocha
- Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Bruno Lemos Batista
- Center for Natural and Human Sciences, Federal University of ABC, Santo Andre, Brazil
| | - Miguel Machinski Junior
- Post-Graduate Program in Health Sciences, State University of Maringa, Maringa, Brazil.,Post-Graduate Program in Food Science, State University of Maringa, Maringa, Brazil.,Department of Basic Health Sciences, State University of Maringa, Maringa, Brazil
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9
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A locust embryo as predictive developmental neurotoxicity testing system for pioneer axon pathway formation. Arch Toxicol 2020; 94:4099-4113. [PMID: 33079231 DOI: 10.1007/s00204-020-02929-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 10/08/2020] [Indexed: 12/31/2022]
Abstract
Exposure to environmental chemicals during in utero and early postnatal development can cause a wide range of neurological defects. Since current guidelines for identifying developmental neurotoxic chemicals depend on the use of large numbers of rodents in animal experiments, it has been proposed to design rapid and cost-efficient in vitro screening test batteries that are mainly based on mixed neuronal/glial cultures. However, cell culture tests do not assay correct wiring of neuronal circuits. The establishment of precise anatomical connectivity is a key event in the development of a functional brain. Here, we expose intact embryos of the locust (Locusta migratoria) in serum-free culture to test chemicals and visualize correct navigation of identified pioneer axons by fluorescence microscopy. We define separate toxicological endpoints for axonal elongation and navigation along a stereotyped pathway. To distinguish developmental neurotoxicity (DNT) from general toxicity, we quantify defects in axonal elongation and navigation in concentration-response curves and compare it to the biochemically determined viability of the embryo. The investigation of a panel of recognized DNT-positive and -negative test compounds supports a rather high predictability of this invertebrate embryo assay. Similar to the semaphorin-mediated guidance of neurites in mammalian cortex, correct axonal navigation of the locust pioneer axons relies on steering cues from members of this family of cell recognition molecules. Due to the evolutionary conserved mechanisms of neurite guidance, we suggest that our pioneer axon paradigm might provide mechanistically relevant information on the DNT potential of chemical agents on the processes of axon elongation, navigation, and fasciculation.
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10
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Bickmeyer U, Meinen I, Meyer S, Kröner S, Brenner M. Fluorescence measurements of the marine flatworm Macrostomum lignano during exposure to TNT and its derivatives 2-ADNT and 4-ADNT. MARINE ENVIRONMENTAL RESEARCH 2020; 161:105041. [PMID: 33070928 DOI: 10.1016/j.marenvres.2020.105041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 05/18/2020] [Accepted: 06/03/2020] [Indexed: 05/27/2023]
Abstract
Fluorescence measurements of the marine flatworm Macrostomum lignano were performed during exposure to the explosive TNT and its main derivatives 2-ADNT and 4-ADNT, using calcein AM, the acetoxymethylester of calcein, and the autofluorescence of its food (diatoms). Lethality was found to depend on temperature and exposure time. After 12 days of exposure to a concentration of 33,3 mg/L 2-ADNT and 4-ADNT, the lethality at 30 °C (100%) was strongly increased compared to 21 °C (~60%). First deaths were observed after four days of exposure. Using lower concentrations (≤3,33 mg/L) of all three compounds, the activity of ABC transporters (ATP binding cassette transporter) was determined using calcein as reporter dye. Worms exposed to toxicants for 72 h showed a significant upregulation of ABC transporter activity during exposure to 3,33 mg/L 2-ADNT and 4-ADNT, and 3 mg/L TNT demonstrating the efficacy of this cellular first line defense. A distinct behavioral defense of the worms decreased the uptake of 2-ADNT and 4-ADNT (0,033 mg/L) as they reduced feeding shown by diminished autofluorescence of algae in the gut.
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Affiliation(s)
- Ulf Bickmeyer
- Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Am Handelshafen 12, D-27570, Bremerhaven, Germany.
| | - Ina Meinen
- Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Am Handelshafen 12, D-27570, Bremerhaven, Germany
| | - Stefanie Meyer
- Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Am Handelshafen 12, D-27570, Bremerhaven, Germany
| | - Svenja Kröner
- Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Am Handelshafen 12, D-27570, Bremerhaven, Germany
| | - Matthias Brenner
- Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Am Handelshafen 12, D-27570, Bremerhaven, Germany
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