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Yadav P, Benner D, Varshney R, Kansara K, Shah K, Dahle L, Kumar A, Rawal R, Gupta S, Bhatia D. Dopamine-Functionalized, Red Carbon Quantum Dots for In Vivo Bioimaging, Cancer Therapeutics, and Neuronal Differentiation. ACS APPLIED BIO MATERIALS 2024; 7:3915-3931. [PMID: 38836645 DOI: 10.1021/acsabm.4c00249] [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] [Indexed: 06/06/2024]
Abstract
One of the crucial requirements of quantum dots for biological applications is their surface modification for very specific and enhanced biological recognition and uptake. Toward this end, we present the green synthesis of bright, red-emitting carbon quantum dots derived from mango leaf extract (mQDs). These mQDs are conjugated electrostatically with dopamine to form mQDs-dopamine (mQDs:DOPA) bioconjugates. Bright-red fluorescence of mQDs was used for bioimaging and uptake in cancerous and noncancerous cell lines, tissues, and in vivo models like zebrafish. mQDs exhibited the highest uptake in brain tissue compared to the heart, kidney, and liver. mQD:DOPA conjugates killed breast cancer cells and increased uptake in epithelial RPE-1 cells and zebrafish. Additionally, mQDs:DOPA promoted neuronal differentiation of SH-SY5Y cells to differentiated neurons. Both mQDs and mQDs:DOPA exhibited the potential for higher collective cell migrations, implicating their future potential as next-generation tools for advanced biological and biomedical applications.
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Affiliation(s)
- Pankaj Yadav
- Biological Engineering Discipline, Indian Institute of Technology (IIT) Gandhinagar, Palaj, Gujarat 382355, India
| | - Dawson Benner
- Department of Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Ritu Varshney
- Biological Engineering Discipline, Indian Institute of Technology (IIT) Gandhinagar, Palaj, Gujarat 382355, India
| | - Krupa Kansara
- Biological Engineering Discipline, Indian Institute of Technology (IIT) Gandhinagar, Palaj, Gujarat 382355, India
| | - Krupa Shah
- Biological Engineering Discipline, Indian Institute of Technology (IIT) Gandhinagar, Palaj, Gujarat 382355, India
| | - Landon Dahle
- Department of Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Ashutosh Kumar
- Biological and Life Sciences Division, School of Arts and Science, Ahmedabad University, Navrangpura, Ahmedabad 380009, India
| | - Rakesh Rawal
- Department of Biochemistry and Forensic Sciences, Gujarat University, Navrangpura, Ahmedabad 380009, India
| | - Sharad Gupta
- Biological Engineering Discipline, Indian Institute of Technology (IIT) Gandhinagar, Palaj, Gujarat 382355, India
| | - Dhiraj Bhatia
- Biological Engineering Discipline, Indian Institute of Technology (IIT) Gandhinagar, Palaj, Gujarat 382355, India
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Salloum-Asfar S, Shin KC, Taha RZ, Khattak S, Park Y, Abdulla SA. The Potential Role of Thyroid Hormone Therapy in Neural Progenitor Cell Differentiation and Its Impact on Neurodevelopmental Disorders. Mol Neurobiol 2024; 61:3330-3342. [PMID: 37991699 PMCID: PMC11087352 DOI: 10.1007/s12035-023-03751-8] [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: 08/22/2023] [Accepted: 10/28/2023] [Indexed: 11/23/2023]
Abstract
Thyroid hormone (T3) plays a vital role in brain development and its dysregulation can impact behavior, nervous system function, and cognitive development. Large case-cohort studies have associated abnormal maternal T3 during early pregnancy to epilepsy, autism, and attention deficit hyperactivity disorder (ADHD) in children. Recent experimental findings have also shown T3's influence on the fate of neural precursor cells and raise the question of its convergence with embryonic neural progenitors. Our objective was to investigate how T3 treatment affects neuronal development and functionality at the cellular level. In vitro experiments using neural precursor cells (NPCs) measured cell growth and numbers after exposure to varying T3 concentrations. Time points included week 0 (W0) representing NPCs treated with 100 nM T3 for 5 days, and differentiated cortical neurons assessed at weeks 3 (W3), 6 (W6), and 8 (W8). Techniques such as single-cell calcium imaging and whole-cell patch clamp were utilized to evaluate neuronal activity and function. IHC staining detected mature neuron markers, and RNA sequencing enabled molecular profiling. W6 and W8 neurons exhibited higher action potential frequencies, with W6 showing increased peak amplitudes and shortened inter-spike intervals by 50%, indicating enhanced activity. Transcriptomic analysis revealed that W6 T3-treated neurons formed a distinct cluster, suggesting accelerated maturation. Comparison with the whole transcriptome further unveiled a correlation between W6 neurons treated with T3 and neuronal regulatory elements associated with autism and ADHD. These findings provide insights into T3's impact on neuronal development and potential mechanisms of T3 dysregulation and neurodevelopmental disorders.
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Affiliation(s)
- Salam Salloum-Asfar
- Neurological Disorders Research Center, Qatar Biomedical Research Institute, Hamad Bin Khalifa University, Qatar Foundation, Doha, Qatar.
| | - Kyung Chul Shin
- Neurological Disorders Research Center, Qatar Biomedical Research Institute, Hamad Bin Khalifa University, Qatar Foundation, Doha, Qatar
| | - Rowaida Z Taha
- Neurological Disorders Research Center, Qatar Biomedical Research Institute, Hamad Bin Khalifa University, Qatar Foundation, Doha, Qatar
| | - Shahryar Khattak
- BESE and KAUST Smart-Health Initiative (KSHI), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Yongsoo Park
- Neurological Disorders Research Center, Qatar Biomedical Research Institute, Hamad Bin Khalifa University, Qatar Foundation, Doha, Qatar
| | - Sara A Abdulla
- Neurological Disorders Research Center, Qatar Biomedical Research Institute, Hamad Bin Khalifa University, Qatar Foundation, Doha, Qatar.
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Rozofsky JP, Pozzuto JM, Byrd-Jacobs CA. Mitral Cell Dendritic Morphology in the Adult Zebrafish Olfactory Bulb following Growth, Injury and Recovery. Int J Mol Sci 2024; 25:5030. [PMID: 38732248 PMCID: PMC11084181 DOI: 10.3390/ijms25095030] [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: 03/25/2024] [Revised: 05/03/2024] [Accepted: 05/04/2024] [Indexed: 05/13/2024] Open
Abstract
The role of afferent target interactions in dendritic plasticity within the adult brain remains poorly understood. There is a paucity of data regarding the effects of deafferentation and subsequent dendritic recovery in adult brain structures. Moreover, although adult zebrafish demonstrate ongoing growth, investigations into the impact of growth on mitral cell (MC) dendritic arbor structure and complexity are lacking. Leveraging the regenerative capabilities of the zebrafish olfactory system, we conducted a comprehensive study to address these gaps. Employing an eight-week reversible deafferentation injury model followed by retrograde labeling, we observed substantial morphological alterations in MC dendrites. Our hypothesis posited that cessation of injury would facilitate recovery of MC dendritic arbor structure and complexity, potentially influenced by growth dynamics. Statistical analyses revealed significant changes in MC dendritic morphology following growth and recovery periods, indicating that MC total dendritic branch length retained significance after 8 weeks of deafferentation injury when normalized to individual fish physical characteristics. This suggests that regeneration of branch length could potentially function relatively independently of growth-related changes. These findings underscore the remarkable plasticity of adult dendritic arbor structures in a sophisticated model organism and highlight the efficacy of zebrafish as a vital implement for studying neuroregenerative processes.
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Affiliation(s)
- John P. Rozofsky
- Department of Biological Sciences, Western Michigan University, 1903 W Michigan Ave., Kalamazoo, MI 49009, USA;
| | - Joanna M. Pozzuto
- Department of Biology, Kalamazoo Valley Community College, 6767 W O Ave., Kalamazoo, MI 49009, USA;
| | - Christine A. Byrd-Jacobs
- Department of Biological Sciences, Western Michigan University, 1903 W Michigan Ave., Kalamazoo, MI 49009, USA;
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Roza M, Eriksson ANM, Svanholm S, Berg C, Karlsson O. Male-transmitted transgenerational effects of the herbicide linuron on DNA methylation profiles in Xenopus tropicalis brain and testis. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 923:170949. [PMID: 38365020 DOI: 10.1016/j.scitotenv.2024.170949] [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: 06/26/2023] [Revised: 01/30/2024] [Accepted: 02/11/2024] [Indexed: 02/18/2024]
Abstract
The herbicide linuron can cause endocrine disrupting effects in Xenopus tropicalis frogs, including offspring that were never exposed to the contaminant. The mechanisms by which these effects are transmitted across generations need to be further investigated. Here, we examined transgenerational alterations of brain and testis DNA methylation profiles paternally inherited from grandfathers developmentally exposed to an environmentally relevant concentration of linuron. Reduced representation bisulfite sequencing (RRBS) revealed numerous differentially methylated regions (DMRs) in brain (3060 DMRs) and testis (2551 DMRs) of the adult male F2 generation. Key genes in the brain involved in somatotropic (igfbp4) and thyrotropic signaling (dio1 and tg) were differentially methylated and correlated with phenotypical alterations in body size, weight, hind limb length and plasma glucose levels, indicating that these methylation changes could be potential mediators of the transgenerational effects of linuron. Testis DMRs were found in genes essential for spermatogenesis, meiosis and germ cell development (piwil1, spo11 and tdrd9) and their methylation levels were correlated with the number of germ cells nests per seminiferous tubule, an endpoint of disrupted spermatogenesis. DMRs were also identified in several genes central for the machinery that regulates the epigenetic landscape including DNA methylation (dnmt3a and mbd2) and histone acetylation (hdac8, ep300, elp3, kat5 and kat14), which may at least partly drive the linuron-induced transgenerational effects. The results from this genome-wide DNA methylation profiling contribute to better understanding of potential transgenerational epigenetic inheritance mechanisms in amphibians.
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Affiliation(s)
- Mauricio Roza
- Science for Life Laboratory, Department of Environmental Science, Stockholm University, Stockholm, Sweden
| | | | - Sofie Svanholm
- Department of Environmental Toxicology, Uppsala University, Uppsala, Sweden
| | - Cecilia Berg
- Department of Environmental Toxicology, Uppsala University, Uppsala, Sweden
| | - Oskar Karlsson
- Science for Life Laboratory, Department of Environmental Science, Stockholm University, Stockholm, Sweden.
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Reimann B, Remy S, Koppen G, Schoeters G, Den Hond E, Nelen V, Franken C, Covaci A, Bruckers L, Baeyens W, Loots I, van Larebeke N, Voorspoels S, De Henauw S, Nawrot TS, Plusquin M. Prenatal exposure to mixtures of per- and polyfluoroalkyl substances and organochlorines affects cognition in adolescence independent of postnatal exposure. Int J Hyg Environ Health 2024; 257:114346. [PMID: 38447259 DOI: 10.1016/j.ijheh.2024.114346] [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: 10/30/2023] [Revised: 02/21/2024] [Accepted: 02/26/2024] [Indexed: 03/08/2024]
Abstract
BACKGROUND Studies on cognitive and neurodevelopmental outcomes have shown inconsistent results regarding the association with prenatal exposure to perfluoroalkyl substance (PFAS) and organochlorines. Assessment of mixture effects of correlated chemical exposures that persist in later life may contribute to the unbiased evaluation and understanding of dose-response associations in real-life exposures. METHODS For a subset of the 4th Flemish Environment and Health Study (FLEHS), concentrations of four PFAS and six organochlorines were measured in respectively 99 and 153-160 cord plasma samples and 15 years later in adolescents' peripheral serum by Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry (UPLC-MS/MS). Sustained and selective attention were measured at 14-15 years with the Continuous Performance Test (CPT) and Stroop Test as indicators of potential neurodevelopmental deficits. Quantile g-computation was applied to assess the joint associations between prenatal exposure to separate and combined groups of PFAS and organochlorines and performance in the CPT and Stroop Test at adolescence. Subsequently, individual effects of each chemical compound were analyzed in mixed effects models with two sets of covariates. Analytical data at birth and at the time of cognitive assessment allowed for off-setting postnatal exposure. RESULTS In mixtures analysis, a simultaneous one-quantile increase in the natural log-transformed values of PFAS and organochlorines combined was associated with a decrease in the mean reaction time (RT) and the reaction time variability (RTV) in the CPT (β = -15.54, 95% CI:-29.64, -1.45, and β = -7.82, 95% CI: -14.97, -0.67 respectively) and for the mixture of PFAS alone with RT (β = -11.94, 95% CI: -23.29, -0.60). In the single pollutant models, these results were confirmed for the association between perfluorohexanesulfonate (PFHxS) with RT (β = -17.95, 95% CI = -33.35, -2.69) and hexachlorobenzene with RTV in the CPT (β = -5.78, 95% CI: -10.39, -0.76). Furthermore, the participants with prenatal exposure above the limit of quantification for perfluorononanoic acid (PFNA) had a significantly shorter RT and RTV in the CPT (β = -23.38, 95% CI: -41.55, -5.94, and β = -9.54, 95% CI: -19.75, -0.43, respectively). CONCLUSION Higher prenatal exposure to a PFAS mixture and a mixture of PFAS and organochlorines combined was associated with better sustained and selective attention during adolescence. The associations seemed to be driven by PFHxS and were not linked to exposure levels at the time of assessment.
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Affiliation(s)
- Brigitte Reimann
- Centre for Environmental Sciences, Hasselt University, 3590, Diepenbeek, Belgium
| | - Sylvie Remy
- Vlaamse Instelling voor Technologisch Onderzoek (VITO), Environmental Toxicology Unit, Mol, Belgium
| | - Gudrun Koppen
- Vlaamse Instelling voor Technologisch Onderzoek (VITO), Environmental Toxicology Unit, Mol, Belgium
| | - Greet Schoeters
- Toxicological Centre, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium
| | - Elly Den Hond
- Provincial Institute of Hygiene, Kronenburgstraat 45, 2000, Antwerp, Belgium; Family Medicine and Population Health (FAMPOP), University of Antwerp, Gouverneur Kingsbergencentrum, Doornstraat 331, 2610, Wilrijk, Belgium
| | - Vera Nelen
- Provincial Institute of Hygiene, Kronenburgstraat 45, 2000, Antwerp, Belgium
| | - Carmen Franken
- Provincial Institute of Hygiene, Kronenburgstraat 45, 2000, Antwerp, Belgium
| | - Adrian Covaci
- Toxicological Centre, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium
| | - Liesbeth Bruckers
- Data Science Institute, Interuniversity Institute for Biostatistics and Statistical Bioinformatics, Hasselt University, 3590, Diepenbeek, Belgium
| | - Willy Baeyens
- Department of Analytical, Environmental and Geochemistry (AMGC), Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050, Elsene, Belgium
| | - Ilse Loots
- University of Antwerp, Department of Sociology (CRESC and IMDO), Sint-Jacobstraat 2, 2000, Antwerp, Belgium
| | - Nicolas van Larebeke
- Department of Analytical, Environmental and Geochemistry (AMGC), Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050, Elsene, Belgium; Study Centre for Carcinogenesis and Primary Prevention of Cancer, Ghent University Hospital, De Pintelaan 185, 9000, Ghent, Belgium
| | - Stefan Voorspoels
- Vlaamse Instelling voor Technologisch Onderzoek (VITO), Environmental Toxicology Unit, Mol, Belgium
| | - Stefaan De Henauw
- Department of Public Health and Primary Care, Ghent University, Ghent, Belgium
| | - Tim S Nawrot
- Centre for Environmental Sciences, Hasselt University, 3590, Diepenbeek, Belgium; School of Public Health, Occupational & Environmental Medicine, Leuven University, 3000, Leuven, Belgium
| | - Michelle Plusquin
- Centre for Environmental Sciences, Hasselt University, 3590, Diepenbeek, Belgium.
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Gerhardt P, Begall S, Frädrich C, Renko K, Heinrich A, Köhrle J, Henning Y. Low thyroxine serves as an upstream regulator of ecophysiological adaptations in Ansell's mole-rats. Front Endocrinol (Lausanne) 2024; 15:1329083. [PMID: 38567302 PMCID: PMC10985354 DOI: 10.3389/fendo.2024.1329083] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 03/04/2024] [Indexed: 04/04/2024] Open
Abstract
Introduction About 10% of all rodent species have evolved a subterranean way of life, although life in subterranean burrows is associated with harsh environmental conditions that would be lethal to most animals living above ground. Two key adaptations for survival in subterranean habitats are low resting metabolic rate (RMR) and core body temperature (Tb). However, the upstream regulation of these traits was unknown thus far. Previously, we have reported exceptionally low concentrations of the thyroid hormone (TH) thyroxine (T4), and peculiarities in TH regulating mechanisms in two African mole-rat species, the naked mole-rat and the Ansell's mole-rat. Methods In the present study, we treated Ansell's mole-rats with T4 for four weeks and analyzed treatment effects on the tissue and whole organism level with focus on metabolism and thermoregulation. Results We found RMR to be upregulated by T4 treatment but not to the extent that was expected based on serum T4 concentrations. Our data point towards an extraordinary capability of Ansell's mole-rats to effectively downregulate TH signaling at tissue level despite very high serum TH concentrations, which most likely explains the observed effects on RMR. On the other hand, body weight was decreased in T4-treated animals and Tb was upregulated by T4 treatment. Moreover, we found indications of the hypothalamus-pituitary-adrenal axis potentially influencing the treatment effects. Conclusion Taken together, we provide the first experimental evidence that the low serum T4 concentrations of Ansell's mole-rats serve as an upstream regulator of low RMR and Tb. Thus, our study contributes to a better understanding of the ecophysiological evolution of the subterranean lifestyle in African mole-rats.
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Affiliation(s)
- Patricia Gerhardt
- Institute of Physiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Sabine Begall
- Department of General Zoology, Faculty of Biology, University of Duisburg-Essen, Essen, Germany
| | - Caroline Frädrich
- Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institut für Experimentelle Endokrinologie, Berlin, Germany
| | - Kostja Renko
- German Federal Institute for Risk Assessment, German Centre for the Protection of Laboratory Animals (Bf3R), Berlin, Germany
| | - Alexandra Heinrich
- Institute of Physiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Josef Köhrle
- Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institut für Experimentelle Endokrinologie, Berlin, Germany
| | - Yoshiyuki Henning
- Institute of Physiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
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Thompson AC, Aizenman CD. Characterization of Na + currents regulating intrinsic excitability of optic tectal neurons. Life Sci Alliance 2024; 7:e202302232. [PMID: 37918964 PMCID: PMC10622587 DOI: 10.26508/lsa.202302232] [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: 06/22/2023] [Revised: 10/20/2023] [Accepted: 10/23/2023] [Indexed: 11/04/2023] Open
Abstract
Developing neurons adapt their intrinsic excitability to maintain stable output despite changing synaptic input. The mechanisms behind this process remain unclear. In this study, we examined Xenopus optic tectal neurons and found that the expressions of Nav1.1 and Nav1.6 voltage-gated Na+ channels are regulated during changes in intrinsic excitability, both during development and becsuse of changes in visual experience. Using whole-cell electrophysiology, we demonstrate the existence of distinct, fast, persistent, and resurgent Na+ currents in the tectum, and show that these Na+ currents are co-regulated with changes in Nav channel expression. Using antisense RNA to suppress the expression of specific Nav subunits, we found that up-regulation of Nav1.6 expression, but not Nav1.1, was necessary for experience-dependent increases in Na+ currents and intrinsic excitability. Furthermore, this regulation was also necessary for normal development of sensory guided behaviors. These data suggest that the regulation of Na+ currents through the modulation of Nav1.6 expression, and to a lesser extent Nav1.1, plays a crucial role in controlling the intrinsic excitability of tectal neurons and guiding normal development of the tectal circuitry.
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Affiliation(s)
- Adrian C Thompson
- https://ror.org/05gq02987 Department of Neuroscience, Brown University, Providence, RI, USA
| | - Carlos D Aizenman
- https://ror.org/05gq02987 Department of Neuroscience, Brown University, Providence, RI, USA
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8
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Haigis AC, Vergauwen L, LaLone CA, Villeneuve DL, O'Brien JM, Knapen D. Cross-species applicability of an adverse outcome pathway network for thyroid hormone system disruption. Toxicol Sci 2023; 195:1-27. [PMID: 37405877 DOI: 10.1093/toxsci/kfad063] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/07/2023] Open
Abstract
Thyroid hormone system disrupting compounds are considered potential threats for human and environmental health. Multiple adverse outcome pathways (AOPs) for thyroid hormone system disruption (THSD) are being developed in different taxa. Combining these AOPs results in a cross-species AOP network for THSD which may provide an evidence-based foundation for extrapolating THSD data across vertebrate species and bridging the gap between human and environmental health. This review aimed to advance the description of the taxonomic domain of applicability (tDOA) in the network to improve its utility for cross-species extrapolation. We focused on the molecular initiating events (MIEs) and adverse outcomes (AOs) and evaluated both their plausible domain of applicability (taxa they are likely applicable to) and empirical domain of applicability (where evidence for applicability to various taxa exists) in a THSD context. The evaluation showed that all MIEs in the AOP network are applicable to mammals. With some exceptions, there was evidence of structural conservation across vertebrate taxa and especially for fish and amphibians, and to a lesser extent for birds, empirical evidence was found. Current evidence supports the applicability of impaired neurodevelopment, neurosensory development (eg, vision) and reproduction across vertebrate taxa. The results of this tDOA evaluation are summarized in a conceptual AOP network that helps prioritize (parts of) AOPs for a more detailed evaluation. In conclusion, this review advances the tDOA description of an existing THSD AOP network and serves as a catalog summarizing plausible and empirical evidence on which future cross-species AOP development and tDOA assessment could build.
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Affiliation(s)
- Ann-Cathrin Haigis
- Zebrafishlab, Veterinary Physiology and Biochemistry, Department of Veterinary Sciences, University of Antwerp, 2610 Wilrijk, Belgium
| | - Lucia Vergauwen
- Zebrafishlab, Veterinary Physiology and Biochemistry, Department of Veterinary Sciences, University of Antwerp, 2610 Wilrijk, Belgium
| | - Carlie A LaLone
- Great Lakes Toxicology and Ecology Division, United States Environmental Protection Agency, Duluth, Minnesota 55804, USA
| | - Daniel L Villeneuve
- Great Lakes Toxicology and Ecology Division, United States Environmental Protection Agency, Duluth, Minnesota 55804, USA
| | - Jason M O'Brien
- Ecotoxicology and Wildlife Health Division, Environment and Climate Change Canada, Carleton University, Ottawa, Ontario K1S 5B6, Canada
| | - Dries Knapen
- Zebrafishlab, Veterinary Physiology and Biochemistry, Department of Veterinary Sciences, University of Antwerp, 2610 Wilrijk, Belgium
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9
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Raj S, Sifuentes CJ, Kyono Y, Denver RJ. Metamorphic gene regulation programs in Xenopus tropicalis tadpole brain. PLoS One 2023; 18:e0287858. [PMID: 37384728 PMCID: PMC10310023 DOI: 10.1371/journal.pone.0287858] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 06/14/2023] [Indexed: 07/01/2023] Open
Abstract
Amphibian metamorphosis is controlled by thyroid hormone (TH), which binds TH receptors (TRs) to regulate gene expression programs that underlie morphogenesis. Gene expression screens using tissues from premetamorphic tadpoles treated with TH identified some TH target genes, but few studies have analyzed genome-wide changes in gene regulation during spontaneous metamorphosis. We analyzed RNA sequencing data at four developmental stages from the beginning to the end of spontaneous metamorphosis, conducted on the neuroendocrine centers of Xenopus tropicalis tadpole brain. We also conducted chromatin immunoprecipitation sequencing (ChIP-seq) for TRs, and we compared gene expression changes during metamorphosis with those induced by exogenous TH. The mRNA levels of 26% of protein coding genes changed during metamorphosis; about half were upregulated and half downregulated. Twenty four percent of genes whose mRNA levels changed during metamorphosis had TR ChIP-seq peaks. Genes involved with neural cell differentiation, cell physiology, synaptogenesis and cell-cell signaling were upregulated, while genes involved with cell cycle, protein synthesis, and neural stem/progenitor cell homeostasis were downregulated. There is a shift from building neural structures early in the metamorphic process, to the differentiation and maturation of neural cells and neural signaling pathways characteristic of the adult frog brain. Only half of the genes modulated by treatment of premetamorphic tadpoles with TH for 16 h changed expression during metamorphosis; these represented 33% of the genes whose mRNA levels changed during metamorphosis. Taken together, our results provide a foundation for understanding the molecular basis for metamorphosis of tadpole brain, and they highlight potential caveats for interpreting gene regulation changes in premetamorphic tadpoles induced by exogenous TH.
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Affiliation(s)
- Samhitha Raj
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Christopher J. Sifuentes
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Yasuhiro Kyono
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Robert J. Denver
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, Michigan, United States of America
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Leemans M, Spirhanzlova P, Couderq S, Le Mével S, Grimaldi A, Duvernois-Berthet E, Demeneix B, Fini JB. A Mixture of Chemicals Found in Human Amniotic Fluid Disrupts Brain Gene Expression and Behavior in Xenopus laevis. Int J Mol Sci 2023; 24:ijms24032588. [PMID: 36768911 PMCID: PMC9916464 DOI: 10.3390/ijms24032588] [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: 11/18/2022] [Revised: 01/16/2023] [Accepted: 01/17/2023] [Indexed: 01/31/2023] Open
Abstract
Thyroid hormones (TH) are essential for normal brain development, influencing neural cell differentiation, migration, and synaptogenesis. Multiple endocrine-disrupting chemicals (EDCs) are found in the environment, raising concern for their potential effects on TH signaling and the consequences on neurodevelopment and behavior. While most research on EDCs investigates the effects of individual chemicals, human health may be adversely affected by a mixture of chemicals. The potential consequences of EDC exposure on human health are far-reaching and include problems with immune function, reproductive health, and neurological development. We hypothesized that embryonic exposure to a mixture of chemicals (containing phenols, phthalates, pesticides, heavy metals, and perfluorinated, polychlorinated, and polybrominated compounds) identified as commonly found in the human amniotic fluid could lead to altered brain development. We assessed its effect on TH signaling and neurodevelopment in an amphibian model (Xenopus laevis) highly sensitive to thyroid disruption. Fertilized eggs were exposed for eight days to either TH (thyroxine, T4 10 nM) or the amniotic mixture (at the actual concentration) until reaching stage NF47, where we analyzed gene expression in the brains of exposed tadpoles using both RT-qPCR and RNA sequencing. The results indicate that whilst some overlap on TH-dependent genes exists, T4 and the mixture have different gene signatures. Immunohistochemistry showed increased proliferation in the brains of T4-treated animals, whereas no difference was observed for the amniotic mixture. Further, we demonstrated diminished tadpoles' motility in response to T4 and mixture exposure. As the individual chemicals composing the mixture are considered safe, these results highlight the importance of examining the effects of mixtures to improve risk assessment.
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Gao J, Luo Y, Lu Y, Wu X, Chen P, Zhang X, Han L, Qiu M, Shen W. Epigenetic regulation of GABAergic differentiation in the developing brain. Front Cell Neurosci 2022; 16:988732. [PMID: 36212693 PMCID: PMC9539098 DOI: 10.3389/fncel.2022.988732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 08/18/2022] [Indexed: 11/13/2022] Open
Abstract
In the vertebrate brain, GABAergic cell development and neurotransmission are important for the establishment of neural circuits. Various intrinsic and extrinsic factors have been identified to affect GABAergic neurogenesis. However, little is known about the epigenetic control of GABAergic differentiation in the developing brain. Here, we report that the number of GABAergic neurons dynamically changes during the early tectal development in the Xenopus brain. The percentage of GABAergic neurons is relatively unchanged during the early stages from stage 40 to 46 but significantly decreased from stage 46 to 48 tadpoles. Interestingly, the histone acetylation of H3K9 is developmentally decreased from stage 42 to 48 (about 3.5 days). Chronic application of valproate acid (VPA), a broad-spectrum histone deacetylase (HDAC) inhibitor, at stage 46 for 48 h increases the acetylation of H3K9 and the number of GABAergic cells in the optic tectum. VPA treatment also reduces apoptotic cells. Electrophysiological recordings show that a VPA induces an increase in the frequency of mIPSCs and no changes in the amplitude. Behavioral studies reveal that VPA decreases swimming activity and visually guided avoidance behavior. These findings extend our understanding of histone modification in the GABAergic differentiation and neurotransmission during early brain development.
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Affiliation(s)
- Juanmei Gao
- College of Life Sciences, Zhejiang University, Hangzhou, China
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Yuhao Luo
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Yufang Lu
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Xiaohua Wu
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Peiyao Chen
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Xinyu Zhang
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Lu Han
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Mengsheng Qiu
- College of Life Sciences, Zhejiang University, Hangzhou, China
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
- *Correspondence: Mengsheng Qiu,
| | - Wanhua Shen
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
- Wanhua Shen,
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12
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Peters H, Laberge F, Heyland A. Latent effect of larval rearing environment on post-metamorphic brain growth in an anuran amphibian. ZOOLOGY 2022; 152:126011. [DOI: 10.1016/j.zool.2022.126011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 03/12/2022] [Accepted: 03/18/2022] [Indexed: 11/29/2022]
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13
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Ta AC, Huang LC, McKeown CR, Bestman JE, Van Keuren-Jensen K, Cline HT. Temporal and spatial transcriptomic dynamics across brain development in Xenopus laevis tadpoles. G3 (BETHESDA, MD.) 2022; 12:jkab387. [PMID: 34751375 PMCID: PMC8728038 DOI: 10.1093/g3journal/jkab387] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 10/26/2021] [Indexed: 11/13/2022]
Abstract
Amphibian metamorphosis is a transitional period that involves significant changes in the cell-type populations and biological processes occurring in the brain. Analysis of gene expression dynamics during this process may provide insight into the molecular events underlying these changes. We conducted differential gene expression analyses of the developing Xenopus laevis tadpole brain during this period in two ways: first, over stages of the development in the midbrain and, second, across regions of the brain at a single developmental stage. We found that genes pertaining to positive regulation of neural progenitor cell proliferation as well as known progenitor cell markers were upregulated in the midbrain prior to metamorphic climax; concurrently, expression of cell cycle timing regulators decreased across this period, supporting the notion that cell cycle lengthening contributes to a decrease in proliferation by the end of metamorphosis. We also found that at the start of metamorphosis, neural progenitor populations appeared to be similar across the fore-, mid-, and hindbrain regions. Genes pertaining to negative regulation of differentiation were upregulated in the spinal cord compared to the rest of the brain, however, suggesting that different programs may regulate neurogenesis there. Finally, we found that regulation of biological processes like cell fate commitment and synaptic signaling follow similar trajectories in the brain across early tadpole metamorphosis and mid- to late-embryonic mouse development. By comparing expression across both temporal and spatial conditions, we have been able to illuminate cell-type and biological pathway dynamics in the brain during metamorphosis.
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Affiliation(s)
- Aaron C Ta
- Neuroscience Department and The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
- Department of Neuroscience, University of California, San Diego, La Jolla, CA 92037, USA
| | - Lin-Chien Huang
- Neuroscience Department and The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Caroline R McKeown
- Neuroscience Department and The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Jennifer E Bestman
- Neuroscience Department and The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | | | - Hollis T Cline
- Neuroscience Department and The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
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14
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Günbey C, Özön A, Gönç EN, Alikaşifoğlu A, Karahan S, Kandemir N. Basal Serum Thyroxine Level should Guide Initial Thyroxine Replacement Dose in Neonates with Congenital Hypothyroidism. J Clin Res Pediatr Endocrinol 2021; 13:269-275. [PMID: 33374096 PMCID: PMC8388053 DOI: 10.4274/jcrpe.galenos.2020.2020.0194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
OBJECTIVE Initial high-dose sodium levothyroxine (Na-LT4) (10-15 μg/kg/day) replacement for primary congenital hypothyroidism (CH) is recommended in guidelines. However, high-dose Na-LT4 risks iatrogenic hyperthyroidism. The aim of this study was to investigate the normalizing effect of varying initial doses of Na-LT4 on serum thyroid hormone levels. METHODS Fifty-two patients were analyzed retrospectively. The patients were classified into mild (27/51.9%), moderate (11/21.1%) and severe (14/26.9%) CH, based on initial free thyroxine (fT4) levels. Time taken to achieve target hormone levels was compared within groups. RESULTS Initial mean Na-LT4 doses for mild, moderate and severe disease were 6.9±3.3, 9.4±2.2 and 10.2±2 μg/kg/day. Serum fT4 levels reached the upper half of normal range (>1.32 ng/dL) in a median of 16, 13 and 16 days in patients with mild, moderate and severe CH with the mean time from initial treatment to first control visit of 14.8±6 days (range 1-36). There was no significant difference in terms of time to achieve target fT4 hormone levels according to disease severity (p=0.478). Seven (25.9%), eight (72.7%) and eight (57.1%) patients experienced hyperthyroxinemia (serum fT4 >1.94 ng/dL) in the mild, moderate, and severe CH groups at the first visit, respectively (p=0.016). CONCLUSION Not all patients diagnosed with CH require high-dose Na-LT4. Initial dose of Na-LT4 may be selected on the basis of pre-treatment thyroid hormone levels. Some patients with moderate and severe CH, experienced iatrogenic hyperthyroxinemia even though the dose was close to the lower limit of the recommended range in guidelines. We suggest that lower initial doses may be appropriate with closer follow-up within the first week.
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Affiliation(s)
- Ceren Günbey
- Hacettepe University Faculty of Medicine, Department of Pediatric Neurology, Ankara, Turkey,* Address for Correspondence: Hacettepe University Faculty of Medicine, Department of Pediatric Neurology, Ankara, Turkey Phone: +90 312 305 11 85 E-mail:
| | - Alev Özön
- Hacettepe University Faculty of Medicine, Department of Pediatric Endocrinology, Ankara, Turkey
| | - E. Nazlı Gönç
- Hacettepe University Faculty of Medicine, Department of Pediatric Endocrinology, Ankara, Turkey
| | - Ayfer Alikaşifoğlu
- Hacettepe University Faculty of Medicine, Department of Pediatric Endocrinology, Ankara, Turkey
| | - Sevilay Karahan
- Hacettepe University Faculty of Medicine, Department of Biostatistics, Ankara, Turkey
| | - Nurgün Kandemir
- Hacettepe University Faculty of Medicine, Department of Pediatric Endocrinology, Ankara, Turkey
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15
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Costa Reis LT, Sena de Souza J, Hirochi Herai R, Cunha EB, Ribeiro Pereira Soares J, Santos El-Bachá R, Diogenes Amaral da Silva V, Aurelio Romano M, Marino Romano R, Izabel Chiamolera M, Giannocco G, Lima Costa S, Dias da Silva MR, Telles da Cunha Lima S. Intergenerational thyroid hormone homeostasis imbalance in cerebellum of rats perinatally exposed to glyphosate-based herbicide. ENVIRONMENTAL TOXICOLOGY 2021; 36:1031-1042. [PMID: 33512083 DOI: 10.1002/tox.23102] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 01/07/2021] [Accepted: 01/10/2021] [Indexed: 05/24/2023]
Abstract
Agrochemicals became a public health concern due to increased human exposure and possible endocrine disruption effects in several organs, including the brain. Thyroid hormones controls neurodevelopment, which turn them sensitive to endocrine disruptors (EDs). In this work, we evaluated the effect of glyphosate-based herbicides (GBH) as an intergenerational endocrine disrupter on thyroid homeostasis in cerebellar cells. Female pregnant Wistar rats were exposed to Roundup Transorb® solution at 5 and 50 mg/kg/day, from gestation day 18 to post-natal day 5 (P5). Cerebellum of male offspring was used to evaluate gene expression. The mRNA levels of thyroid hormone receptors, hormonal conversion enzymes, hormone transporters, as well as, de novo epigenetic regulators were altered, with some of these genes presenting a non-monotonic dose response. Furthermore, metabolomic profile correlation with tested dose demonstrated altered metabolic profile, in agreement with cerebellar gene alterations. Moreover, cerebellar primary cultures exposed to non-toxic GBH concentration presented a decrease level in glial fibrillary acidic protein, a protein regulated by endocrine signals. In conclusion, our results indicate that animals exposed to non-toxic GBH doses during perinatal phase carry intergenerational alterations in key regulators of cellular thyroid hormone homeostasis and epigenetic controllers in adulthood, indicating the possible ED effect of GBH based on epigenetic alterations.
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Affiliation(s)
- Luã Tainã Costa Reis
- Laboratório de Bioprospecção e Biotecnologia Instituto de Biologia, Universidade Federal da Bahia (UFBA), Salvador, Brazil
| | - Janaina Sena de Souza
- Departamento de Medicina Disciplina de Endocrinologia Clínica, Universidade Federal de São Paulo (UNIFESP/EPM), São Paulo, Brazil
| | - Roberto Hirochi Herai
- Graduate Program in Health Sciences, School of Medicine, Pontifícia Universidade Católica do Paraná (PUCPR), Curitiba, Brazil
- Research Department, Lico Kaesemodel Institute, Curitiba, Paraná, Brazil
| | - Eduardo Brunetti Cunha
- Graduate Program in Health Sciences, School of Medicine, Pontifícia Universidade Católica do Paraná (PUCPR), Curitiba, Brazil
| | | | - Ramon Santos El-Bachá
- Laboratório de Neuroquímica e Biologia Celular, Universidade Federal da Bahia (UFBA), Salvador, Brazil
| | | | - Marco Aurelio Romano
- Departamento de Farmácia, Universidade Estadual do Centro-Oeste (UNICENTRO), Guarapuava, Brazil
| | - Renata Marino Romano
- Departamento de Farmácia, Universidade Estadual do Centro-Oeste (UNICENTRO), Guarapuava, Brazil
| | - Maria Izabel Chiamolera
- Departamento de Medicina Disciplina de Endocrinologia Clínica, Universidade Federal de São Paulo (UNIFESP/EPM), São Paulo, Brazil
| | - Gisele Giannocco
- Departamento de Medicina Disciplina de Endocrinologia Clínica, Universidade Federal de São Paulo (UNIFESP/EPM), São Paulo, Brazil
| | - Silvia Lima Costa
- Laboratório de Neuroquímica e Biologia Celular, Universidade Federal da Bahia (UFBA), Salvador, Brazil
| | - Magnus Régios Dias da Silva
- Departamento de Medicina Disciplina de Endocrinologia Clínica, Universidade Federal de São Paulo (UNIFESP/EPM), São Paulo, Brazil
| | - Suzana Telles da Cunha Lima
- Laboratório de Bioprospecção e Biotecnologia Instituto de Biologia, Universidade Federal da Bahia (UFBA), Salvador, Brazil
- AnaclinGENE, Curitiba, Paraná, Brazil
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16
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Sood C, Doyle SE, Siegrist SE. Steroid hormones, dietary nutrients, and temporal progression of neurogenesis. CURRENT OPINION IN INSECT SCIENCE 2021; 43:70-77. [PMID: 33127508 PMCID: PMC8058227 DOI: 10.1016/j.cois.2020.10.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 10/10/2020] [Accepted: 10/16/2020] [Indexed: 05/13/2023]
Abstract
Temporal patterning of neural progenitors, in which different factors are sequentially expressed, is an evolutionarily conserved strategy for generating neuronal diversity during development. In the Drosophila embryo, mechanisms that mediate temporal patterning of neural stem cells (neuroblasts) are largely cell-intrinsic. However, after embryogenesis, neuroblast temporal patterning relies on extrinsic cues as well, as freshly hatched larvae seek out nutrients and other key resources in varying natural environments. We recap current understanding of neuroblast-intrinsic temporal programs and discuss how neuroblast extrinsic cues integrate and coordinate with neuroblast intrinsic programs to control numbers and types of neurons produced. One key emerging extrinsic factor that impacts temporal patterning of neuroblasts and their daughters as well as termination of neurogenesis is the steroid hormone, ecdysone, a known regulator of large-scale developmental transitions in insects and arthropods. Lastly, we consider evolutionary conservation and discuss recent work on thyroid hormone signaling in early vertebrate brain development.
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Affiliation(s)
- Chhavi Sood
- Department of Biology, University of Virginia, Charlottesville, VA 22904, USA
| | - Susan E Doyle
- Department of Biology, University of Virginia, Charlottesville, VA 22904, USA
| | - Sarah E Siegrist
- Department of Biology, University of Virginia, Charlottesville, VA 22904, USA.
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17
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Gao J, Shen W. Xenopus in revealing developmental toxicity and modeling human diseases. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 268:115809. [PMID: 33096388 DOI: 10.1016/j.envpol.2020.115809] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Revised: 10/01/2020] [Accepted: 10/09/2020] [Indexed: 06/11/2023]
Abstract
The Xenopus model offers many advantages for investigation of the molecular, cellular, and behavioral mechanisms underlying embryo development. Moreover, Xenopus oocytes and embryos have been extensively used to study developmental toxicity and human diseases in response to various environmental chemicals. This review first summarizes recent advances in using Xenopus as a vertebrate model to study distinct types of tissue/organ development following exposure to environmental toxicants, chemical reagents, and pharmaceutical drugs. Then, the successful use of Xenopus as a model for diseases, including fetal alcohol spectrum disorders, autism, epilepsy, and cardiovascular disease, is reviewed. The potential application of Xenopus in genetic and chemical screening to protect against embryo deficits induced by chemical toxicants and related diseases is also discussed.
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Affiliation(s)
- Juanmei Gao
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, 311121, China; College of Life and Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Wanhua Shen
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, 311121, China.
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18
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Experience-Dependent Development of Dendritic Arbors in Mouse Visual Cortex. J Neurosci 2020; 40:6536-6556. [PMID: 32669356 DOI: 10.1523/jneurosci.2910-19.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 06/26/2020] [Accepted: 06/30/2020] [Indexed: 12/27/2022] Open
Abstract
The dendritic arbor of neurons constrains the pool of available synaptic partners and influences the electrical integration of synaptic currents. Despite these critical functions, our knowledge of the dendritic structure of cortical neurons during early postnatal development and how these dendritic structures are modified by visual experience is incomplete. Here, we present a large-scale dataset of 849 3D reconstructions of the basal arbor of pyramidal neurons collected across early postnatal development in visual cortex of mice of either sex. We found that the basal arbor grew substantially between postnatal day 7 (P7) and P30, undergoing a 45% increase in total length. However, the gross number of primary neurites and dendritic segments was largely determined by P7. Growth from P7 to P30 occurred primarily through extension of dendritic segments. Surprisingly, comparisons of dark-reared and typically reared mice revealed that a net gain of only 15% arbor length could be attributed to visual experience; most growth was independent of experience. To examine molecular contributions, we characterized the role of the activity-regulated small GTPase Rem2 in both arbor development and the maintenance of established basal arbors. We showed that Rem2 is an experience-dependent negative regulator of dendritic segment number during the visual critical period. Acute deletion of Rem2 reduced directionality of dendritic arbors. The data presented here establish a highly detailed, quantitative analysis of basal arbor development that we believe has high utility both in understanding circuit development as well as providing a framework for computationalists wishing to generate anatomically accurate neuronal models.SIGNIFICANCE STATEMENT Dendrites are the sites of the synaptic connections among neurons. Despite their importance for neural circuit function, only a little is known about the postnatal development of dendritic arbors of cortical pyramidal neurons and the influence of experience. Here we show that the number of primary basal dendritic arbors is already established before eye opening, and that these arbors primarily grow through lengthening of dendritic segments and not through addition of dendritic segments. Surprisingly, visual experience has a modest net impact on overall arbor length (15%). Experiments in KO animals revealed that the gene Rem2 is positive regulator of dendritic length and a negative regulator of dendritic segments.
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19
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Dahora LI, Fitzgerald A, Emanuel M, Baiges AF, Husain Z, Thompson CK. The Flavor Enhancer Maltol Increases Pigment Aggregation in Dermal and Neural Melanophores in Xenopus laevis Tadpoles. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2020; 39:381-395. [PMID: 31721268 DOI: 10.1002/etc.4626] [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: 05/17/2019] [Revised: 06/26/2019] [Accepted: 10/18/2019] [Indexed: 06/10/2023]
Abstract
Melanophores are pigmented cells that change the distribution of melanosomes, enabling animals to appear lighter or darker for camouflage, thermoregulation, and protection from ultraviolet radiation. A complex series of hormonal and neural mechanisms regulates melanophore pigment distribution, making these dynamic cells a valuable tool to screen toxicants as they rapidly respond to changes in the environment. We found that maltol, a naturally occurring flavor enhancer and fragrance agent, induces melanophore pigment aggregation in a dose-dependent manner in Xenopus laevis tadpoles. To determine if maltol affects camouflage adaptation, we placed tadpoles into maltol baths situated over either a white or a black background. Maltol induced pigment aggregation in a similar dose-dependent pattern regardless of background color. We also tested how maltol treatment compares to melatonin treatment and found that the degree of pigment aggregation induced by maltol is similar to treatment with melatonin but that maltol induces over a much longer time course. Last, maltol had no effect on mRNA expression in the brain of genes that regulate camouflage-related pigment aggregation. The present results suggest that maltol does not exert its effects via the camouflage adaptation mechanism or via melatonin-related mechanisms. These results are the first to identify a putative toxicological effect of maltol exposure in vivo and rule out several mechanisms by which maltol may exert its effects on pigment aggregation. Environ Toxicol Chem 2020;39:381-395. © 2019 SETAC.
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Affiliation(s)
- Lara I Dahora
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, USA
| | | | - Matthew Emanuel
- School of Neuroscience, Virginia Tech, Blacksburg, Virginia, USA
| | - Alexa F Baiges
- School of Neuroscience, Virginia Tech, Blacksburg, Virginia, USA
| | - Zahabiya Husain
- School of Neuroscience, Virginia Tech, Blacksburg, Virginia, USA
| | - Christopher K Thompson
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, USA
- School of Neuroscience, Virginia Tech, Blacksburg, Virginia, USA
- Global Change Center, Virginia Tech, Blacksburg, Virginia, USA
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20
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Gothié J, Vancamp P, Demeneix B, Remaud S. Thyroid hormone regulation of neural stem cell fate: From development to ageing. Acta Physiol (Oxf) 2020; 228:e13316. [PMID: 31121082 PMCID: PMC9286394 DOI: 10.1111/apha.13316] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 05/10/2019] [Accepted: 05/17/2019] [Indexed: 12/13/2022]
Abstract
In the vertebrate brain, neural stem cells (NSCs) generate both neuronal and glial cells throughout life. However, their neuro‐ and gliogenic capacity changes as a function of the developmental context. Despite the growing body of evidence on the variety of intrinsic and extrinsic factors regulating NSC physiology, their precise cellular and molecular actions are not fully determined. Our review focuses on thyroid hormone (TH), a vital component for both development and adult brain function that regulates NSC biology at all stages. First, we review comparative data to analyse how TH modulates neuro‐ and gliogenesis during vertebrate brain development. Second, as the mammalian brain is the most studied, we highlight the molecular mechanisms underlying TH action in this context. Lastly, we explore how the interplay between TH signalling and cell metabolism governs both neurodevelopmental and adult neurogenesis. We conclude that, together, TH and cellular metabolism regulate optimal brain formation, maturation and function from early foetal life to adult in vertebrate species.
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Affiliation(s)
- Jean‐David Gothié
- Department of Neurology & Neurosurgery Montreal Neurological Institute & Hospital, McGill University Montreal Quebec Canada
| | - Pieter Vancamp
- CNRS UMR 7221 Muséum National d’Histoire Naturelle Paris France
| | | | - Sylvie Remaud
- CNRS UMR 7221 Muséum National d’Histoire Naturelle Paris France
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21
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Novales Flamarique I, Sayed Ahmed A, Cheng CL, Molday RS, Devlin RH. Growth hormone regulates opsin expression in the retina of a salmonid fish. J Neuroendocrinol 2019; 31:e12804. [PMID: 31630448 DOI: 10.1111/jne.12804] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 09/07/2019] [Accepted: 10/18/2019] [Indexed: 01/18/2023]
Abstract
Colour vision relies on retinal photoreceptors that express a different predominant visual pigment protein (opsin). In several vertebrates, the primary opsin expressed by a photoreceptor can change throughout ontogeny, although the molecular factors that influence such regulation are poorly understood. One of these factors is thyroid hormone which, together with its receptors, modulates opsin expression in the retinas of multiple vertebrates including rodents and salmonid fishes. In the latter, thyroid hormone induces a switch in opsin expression from SWS1 (ultraviolet light sensitive) to SWS2 (short wavelength or blue light sensitive) in the single cone photoreceptors of the retina. The actions of other hormones on opsin expression have not been investigated. In the present study, we used a transgenic strain of coho salmon (Oncorhynchus kitsutch) with enhanced levels of circulating growth hormone compared to that of wild siblings to assess the effects of this hormone on the SWS1 to SWS2 opsin switch. Transgenic fish showed a developmentally accelerated opsin switch compared to size-matched controls as assessed by immunohistological and in situ hybridisation labelling of photoreceptors and by quantification of transcripts using quantitative polymerase chain reaction. This accelerated switch led to a different spectral sensitivity maximum, under a middle to long wavelength adapting background, from ultraviolet (λmax ~ 380 nm) in controls to short wavelengths (λmax ~ 430 nm) in transgenics, demonstrating altered colour vision. The effects of growth hormone over-expression were independent of circulating levels of thyroid hormone (triiodothyronine), the hormone typically associated with opsin switches in vertebrates.
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Affiliation(s)
- Inigo Novales Flamarique
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada
- Department of Biology, University of Victoria, Victoria, BC, Canada
| | - Ahmed Sayed Ahmed
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Christiana L Cheng
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
| | - Robert S Molday
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
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22
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Hope SF, Buenaventura CR, Husain Z, DuRant SE, Kennamer RA, Hopkins WA, Thompson CK. Limited Support for Thyroid Hormone or Corticosterone Related Gene Expression as a Proximate Mechanism of Incubation Temperature-Dependent Phenotypes in Birds. Front Physiol 2019; 10:857. [PMID: 31333499 PMCID: PMC6624749 DOI: 10.3389/fphys.2019.00857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 06/20/2019] [Indexed: 11/13/2022] Open
Abstract
The conditions that animals experience during early development can have profound consequences for health and fitness. In birds, one of the most important aspects of development is egg incubation temperature. A small decrease in average temperature leads to various impacts on offspring phenotype, such as smaller body sizes, slower growth rates, and less efficient metabolic activity. Little is known, however, about the proximate mechanisms underlying these incubation temperature-induced phenotypic changes. Two important hormones which could play a proximate role are thyroid hormone and corticosterone, which mobilize stored energy reserves and coordinate the normal growth of tissues, particularly in the brain. Previous research shows that circulating blood concentrations of both hormones are influenced by incubation temperature, but the mechanism by which incubation temperature may lead to these changes is unknown. We hypothesized that incubation temperature induces changes in thyroid hormone and corticosterone regulation, leading to changes in expression of hormone-sensitive genes in the brain. To test this, we incubated wood duck (Aix sponsa) eggs at three different temperatures within the natural range (35.0, 35.8, and 37.0°C). We measured mRNA expression of thyroid hormone-related neuroendocrine endpoints (deiodinase 2/3, thyroid hormone receptor α/β, neural regeneration related protein, and Krueppel-like factor 9) in newly hatched ducklings and corticosterone-related neuroendocrine endpoints (mineralocorticoid receptor, glucocorticoid receptor, cholecystokinin, and brain-derived neurotrophic factor) in 15 day-old ducklings using qPCR on brain tissue from the hippocampus and hypothalamus. Contrary to our predictions, we found that mRNA expression of thyroid hormone-related endpoints in both brain areas were largely unaffected by incubation temperature, although there was a trend for an inverse relationship between mRNA expression and incubation temperature for several genes in the hypothalamus. We also found that mineralocorticoid receptor mRNA expression in the hypothalamus was lower in ducklings incubated at the low relative to the high temperatures. This study is the first to evaluate the effects of incubation temperature on mRNA expression of neuroendocrine endpoints in the developing avian brain and suggests that these particular endpoints may be largely resistant to changes in incubation temperature. Thus, further research into the proximate mechanisms for incubation temperature-induced developmental plasticity is needed.
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Affiliation(s)
- Sydney F. Hope
- Department of Fish and Wildlife Conservation, Virginia Tech, Blacksburg, VA, United States
| | | | - Zahabiya Husain
- School of Neuroscience, Virginia Tech, Blacksburg, VA, United States
| | - Sarah E. DuRant
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR, United States
| | - Robert A. Kennamer
- Savannah River Ecology Laboratory, University of Georgia, Aiken, SC, United States
| | - William A. Hopkins
- Department of Fish and Wildlife Conservation, Virginia Tech, Blacksburg, VA, United States
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Williams DL. From axolotl to zebrafish: a comparative approach to the study of thyroid involvement in ocular development. Eye (Lond) 2019; 33:218-222. [PMID: 30482907 PMCID: PMC6367386 DOI: 10.1038/s41433-018-0288-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 10/24/2018] [Accepted: 11/14/2018] [Indexed: 02/02/2023] Open
Abstract
While discussion of interactions between the thyroid gland and the eye mostly focus on thyroid eye disease, the involvement of the thyroid and its hormones on development of the eye before birth is also an important perspective that should not be forgotten. Experimental models involving amphibians and fish are valuable both because the developing larvae are not constrained within the adult but can be observed and manipulated as they grow autonomously and also because they metamorphose with substantial morphological changes driven by the hypothalamo-pituitary-thyroid axis occurring as they develop from eggs to adults. In this paper we will first discuss changes seen in the axolotl, a naturally occurring neotonous hypothyroid salamander and the Xenopus toad a widely used laboratory amphibian. Secondly we will document ocular changes in flatfish which exhibit remarkable anatomical alterations during their change from a pelagic to benthic lifestyle. Finally we will evaluate ocular changes in developing zebrafish when subjected to thyroid-disrupting chemicals. These experiments show the influence of the thyroid on ocular development when thyroid function is altered which may be of value in determining changes in human hypothyroid infants but are also important to note as these chemicals are widely used in plastics and also as flame retardants used to control wildfires. Run-off into water courses can damage both wildlife and humans consuming contaminated water and thyroid disruption may have significant effects on reproduction and development, although influences on ocular morphology have yet to be investigated.
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Affiliation(s)
- David L Williams
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, UK.
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Prezioso G, Giannini C, Chiarelli F. Effect of Thyroid Hormones on Neurons and Neurodevelopment. Horm Res Paediatr 2019; 90:73-81. [PMID: 30157487 DOI: 10.1159/000492129] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 07/15/2018] [Indexed: 11/19/2022] Open
Abstract
This review focuses on the current knowledge of the effects of thyroid hormones on central nervous system differentiation and development in animals and the human fetal brain. The outcomes of children with congenital hypothyroidism and of newborns with hypothyroid pregnant mothers are emphasized, focusing on how therapies could affect and especially improve the outcomes.
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25
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Purnama MTE, Rahmaningtyas IH, Pratama AR, Prastika Z, Kartikasari AM, Cahyo NPD. Tadpole serum activity ( Rana catesbeian a) in caspase-3 as a marker of the role of apoptosis and total cytotoxic T lymphocytes in albino rats' epithelial cells induced by neoplasia. Vet World 2019; 12:63-67. [PMID: 30936655 PMCID: PMC6431812 DOI: 10.14202/vetworld.2019.63-67] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 11/26/2018] [Indexed: 11/16/2022] Open
Abstract
AIM This study was conducted to examine the tadpole's serum activity (Rana catesbeiana) in caspase-3 as a marker of the role of apoptosis and total cytotoxic T lymphocyte (CTL) in albino rats' epithelial cells induced by neoplasia. Tadpole serumcontains thyroxine hormone that may cause the metamorphosis process and control cell proliferation. MATERIALS AND METHODS Male rats were induced by 7,12-dimethylbenz (α)anthracene (DMBA) 20 mg/rats twice every week over 5 weeks to stimulate skin neoplasia. Tadpole serum injected intracutaneously after neoplasia is known. The negative control group (C-) was not exposed to DMBA and tadpole serum, while the positive control group (C+) was exposed to DMBA. Treatment groups (T1, T2, and T3) were exposed DMBA and tadpole serum 100%, 75%, and 25%/rat/day, respectively. Samples of skin organ were be made preparations immunohistochemistry interacted with caspase-3 and CTL antibody as the marker. RESULTS Based on the result, immunohistochemistry from skin neoplasia and given therapy of tadpole serum show that Treatment 1 was the highest caspase-3 and CTL expression. The result of caspase-3 expression in C-, C+, T1, T2, and T3 was 0.00c±0.000, 0.70bc±0.141, 2.00a±0.283, 1.10b±0.424, and 1.15b±0.495, respectively. The result of CTL expression in C-, C+, T1, T2, and T3 was 0.10d±0.200, 1.00c±0.230, 2.10a±0.529, 1.70ab±0.258, and 1.35bc±0.443, respectively. CONCLUSION It can be concluded from the study that tadpole serum (R. catesbeiana) 100% concentration can increase caspase-3 and total CTL in albino rats' epithelial cells induced by neoplasia.
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Affiliation(s)
- M. T. E. Purnama
- Department of Veterinary Anatomy, Faculty of Veterinary Medicine, Universitas Airlangga, Mulyorejo Campus C Surabaya, East Java 60115, Indonesia
| | - I. H. Rahmaningtyas
- Department of Veterinary Anatomy, Faculty of Veterinary Medicine, Universitas Airlangga, Mulyorejo Campus C Surabaya, East Java 60115, Indonesia
| | - A. R. Pratama
- Department of Veterinary Anatomy, Faculty of Veterinary Medicine, Universitas Airlangga, Mulyorejo Campus C Surabaya, East Java 60115, Indonesia
| | - Z. Prastika
- Department of Veterinary Anatomy, Faculty of Veterinary Medicine, Universitas Airlangga, Mulyorejo Campus C Surabaya, East Java 60115, Indonesia
| | - A. M. Kartikasari
- Department of Veterinary Pathology, Faculty of Veterinary Medicine, Universitas Airlangga, Mulyorejo Campus C Surabaya, East Java 60115, Indonesia
| | - N. P. D. Cahyo
- Department of Veterinary Pathology, Faculty of Veterinary Medicine, Universitas Airlangga, Mulyorejo Campus C Surabaya, East Java 60115, Indonesia
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26
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Vancamp P, Darras VM. From zebrafish to human: A comparative approach to elucidate the role of the thyroid hormone transporter MCT8 during brain development. Gen Comp Endocrinol 2018; 265:219-229. [PMID: 29183795 DOI: 10.1016/j.ygcen.2017.11.023] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 11/24/2017] [Accepted: 11/24/2017] [Indexed: 02/07/2023]
Abstract
Monocarboxylate transporter 8 (MCT8) facilitates transmembrane transport of thyroid hormones (THs) ensuring their action on gene expression during vertebrate neurodevelopment. A loss of MCT8 in humans results in severe psychomotor deficits associated with the Allan-Herndon-Dudley Syndrome (AHDS). However, where and when exactly a lack of MCT8 causes the neurological manifestations remains unclear because of the varying expression pattern of MCT8 between specific brain regions and cells. Here, we elaborate on the animal models that have been generated to elucidate the mechanisms underlying MCT8-deficient brain development. The absence of a clear neurological phenotype in Mct8 knockout mice made it clear that a single species would not suffice. The evolutionary conservation of TH action on neurodevelopment as well as the components regulating TH signalling however offers the opportunity to answer different aspects of MCT8 function in brain development using different vertebrate species. Moreover, the plethora of tools for genome editing available today facilitates gene silencing in these animals as well. Studies in the recently generated mct8-deficient zebrafish and Mct8/Oatp1c1 double knockout mice have put forward the current paradigm of impaired TH uptake at the level of the blood-brain barrier during peri- and postnatal development as being the main pathophysiological mechanism of AHDS. RNAi vector-based, cell-specific induction of MCT8 knockdown in the chicken embryo points to an additional function of MCT8 at the level of the neural progenitors during early brain development. Future studies including also additional in vivo models like Xenopus or in vitro approaches such as induced pluripotent stem cells will continue to help unravelling the exact role of MCT8 in developmental events. In the end, this multispecies approach will lead to a unifying thesis regarding the cellular and molecular mechanisms responsible for the neurological phenotype in AHDS patients.
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Affiliation(s)
- Pieter Vancamp
- KU Leuven, Laboratory of Comparative Endocrinology, Department of Biology, B-3000 Leuven, Belgium
| | - Veerle M Darras
- KU Leuven, Laboratory of Comparative Endocrinology, Department of Biology, B-3000 Leuven, Belgium.
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27
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Abstract
Circuit operations are determined jointly by the properties of the circuit elements and the properties of the connections among these elements. In the nervous system, neurons exhibit diverse morphologies and branching patterns, allowing rich compartmentalization within individual cells and complex synaptic interactions among groups of cells. In this review, we summarize work detailing how neuronal morphology impacts neural circuit function. In particular, we consider example neurons in the retina, cerebral cortex, and the stomatogastric ganglion of crustaceans. We also explore molecular coregulators of morphology and circuit function to begin bridging the gap between molecular and systems approaches. By identifying motifs in different systems, we move closer to understanding the structure-function relationships that are present in neural circuits.
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Affiliation(s)
| | - Stephen D Van Hooser
- Department of Biology, Brandeis University , Waltham, Massachusetts.,Volen Center for Complex Systems, Brandeis University , Waltham, Massachusetts.,Sloan-Swartz Center for Theoretical Neurobiology, Brandeis University , Waltham, Massachusetts
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28
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Ruuskanen S, Hsu BY. Maternal Thyroid Hormones: An Unexplored Mechanism Underlying Maternal Effects in an Ecological Framework. Physiol Biochem Zool 2018; 91:904-916. [DOI: 10.1086/697380] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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29
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Liu HH, McClatchy DB, Schiapparelli L, Shen W, Yates JR, Cline HT. Role of the visual experience-dependent nascent proteome in neuronal plasticity. eLife 2018; 7:e33420. [PMID: 29412139 PMCID: PMC5815848 DOI: 10.7554/elife.33420] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 02/05/2018] [Indexed: 01/02/2023] Open
Abstract
Experience-dependent synaptic plasticity refines brain circuits during development. To identify novel protein synthesis-dependent mechanisms contributing to experience-dependent plasticity, we conducted a quantitative proteomic screen of the nascent proteome in response to visual experience in Xenopus optic tectum using bio-orthogonal metabolic labeling (BONCAT). We identified 83 differentially synthesized candidate plasticity proteins (CPPs). The CPPs form strongly interconnected networks and are annotated to a variety of biological functions, including RNA splicing, protein translation, and chromatin remodeling. Functional analysis of select CPPs revealed the requirement for eukaryotic initiation factor three subunit A (eIF3A), fused in sarcoma (FUS), and ribosomal protein s17 (RPS17) in experience-dependent structural plasticity in tectal neurons and behavioral plasticity in tadpoles. These results demonstrate that the nascent proteome is dynamic in response to visual experience and that de novo synthesis of machinery that regulates RNA splicing and protein translation is required for experience-dependent plasticity.
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Affiliation(s)
- Han-Hsuan Liu
- The Dorris Neuroscience CenterThe Scripps Research InstituteLa JollaUnited States
- Department of NeuroscienceThe Scripps Research InstituteLa JollaUnited States
- Kellogg School of Science and TechnologyThe Scripps Research InstituteLa JollaUnited States
| | - Daniel B McClatchy
- Department of Molecular MedicineThe Scripps Research InstituteLa JollaUnited States
| | - Lucio Schiapparelli
- The Dorris Neuroscience CenterThe Scripps Research InstituteLa JollaUnited States
- Department of NeuroscienceThe Scripps Research InstituteLa JollaUnited States
| | - Wanhua Shen
- The Dorris Neuroscience CenterThe Scripps Research InstituteLa JollaUnited States
- Department of NeuroscienceThe Scripps Research InstituteLa JollaUnited States
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental SciencesHangzhou Normal UniversityHangzhouChina
| | - John R Yates
- Department of NeuroscienceThe Scripps Research InstituteLa JollaUnited States
- Department of Molecular MedicineThe Scripps Research InstituteLa JollaUnited States
| | - Hollis T Cline
- The Dorris Neuroscience CenterThe Scripps Research InstituteLa JollaUnited States
- Department of NeuroscienceThe Scripps Research InstituteLa JollaUnited States
- Kellogg School of Science and TechnologyThe Scripps Research InstituteLa JollaUnited States
- Department of Molecular MedicineThe Scripps Research InstituteLa JollaUnited States
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30
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Vancamp P, Darras VM. Dissecting the role of regulators of thyroid hormone availability in early brain development: Merits and potential of the chicken embryo model. Mol Cell Endocrinol 2017; 459:71-78. [PMID: 28153797 DOI: 10.1016/j.mce.2017.01.045] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 01/24/2017] [Accepted: 01/26/2017] [Indexed: 10/20/2022]
Abstract
Thyroid hormones (THs) are important mediators of vertebrate central nervous system (CNS) development, thereby regulating the expression of a wide variety of genes by binding to nuclear TH receptors. TH transporters and deiodinases are both needed to ensure appropriate intracellular TH availability, but the precise function of each of these regulators and their coaction during brain development is only partially understood. Rodent knockout models already provided some crucial insights, but their in utero development severely hampers research regarding the role of TH regulators during early embryonic stages. The establishment of novel gain- and loss-of-function techniques has boosted the position of externally developing non-mammalian vertebrates as research models in developmental endocrinology. Here, we elaborate on the chicken as a model organism to elucidate the function of TH regulators during embryonic CNS development. The fast-developing, relatively big and accessible embryo allows easy experimental manipulation, especially at early stages of brain development. Recent data on the characterisation and spatiotemporal expression pattern of different TH regulators in embryonic chicken CNS have provided the necessary background to dissect the function of each of them in more detail. We highlight some recent advances and important strategies to investigate the role of TH transporters and deiodinases in various CNS structures like the brain barriers, the cerebellum, the retina and the hypothalamus. Exploiting the advantages of this non-classical model can greatly contribute to complete our understanding of the regulation of TH bioavailability throughout embryonic CNS development.
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Affiliation(s)
- Pieter Vancamp
- KU Leuven, Laboratory of Comparative Endocrinology, Department of Biology, B-3000, Leuven, Belgium
| | - Veerle M Darras
- KU Leuven, Laboratory of Comparative Endocrinology, Department of Biology, B-3000, Leuven, Belgium.
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31
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Deficiency of the Thyroid Hormone Transporter Monocarboxylate Transporter 8 in Neural Progenitors Impairs Cellular Processes Crucial for Early Corticogenesis. J Neurosci 2017; 37:11616-11631. [PMID: 29109240 DOI: 10.1523/jneurosci.1917-17.2017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 10/02/2017] [Indexed: 11/21/2022] Open
Abstract
Thyroid hormones (THs) are essential for establishing layered brain structures, a process called corticogenesis, by acting on transcriptional activity of numerous genes. In humans, deficiency of the monocarboxylate transporter 8 (MCT8), involved in cellular uptake of THs before their action, results in severe neurological abnormalities, known as the Allan-Herndon-Dudley syndrome. While the brain lesions predominantly originate prenatally, it remains unclear how and when exactly MCT8 dysfunction affects cellular processes crucial for corticogenesis. We investigated this by inducing in vivo RNAi vector-based knockdown of MCT8 in neural progenitors of the chicken optic tectum, a layered structure that shares many developmental features with the mammalian cerebral cortex. MCT8 knockdown resulted in cellular hypoplasia and a thinner optic tectum. This could be traced back to disrupted cell-cycle kinetics and a premature shift to asymmetric cell divisions impairing progenitor cell pool expansion. Birth-dating experiments confirmed diminished neurogenesis in the MCT8-deficient cell population as well as aberrant migration of both early-born and late-born neuroblasts, which could be linked to reduced reelin signaling and disorganized radial glial cell fibers. Impaired neurogenesis resulted in a reduced number of glutamatergic and GABAergic neurons, but the latter additionally showed decreased differentiation. Moreover, an accompanying reduction in untransfected GABAergic neurons suggests hampered intercellular communication. These results indicate that MCT8-dependent TH uptake in the neural progenitors is essential for early events in corticogenesis, and help to understand the origin of the problems in cortical development and function in Allan-Herndon-Dudley syndrome patients.SIGNIFICANCE STATEMENT Thyroid hormones (THs) are essential to establish the stereotypical layered structure of the human forebrain during embryonic development. Before their action on gene expression, THs require cellular uptake, a process facilitated by the TH transporter monocarboxylate transporter 8 (MCT8). We investigated how and when dysfunctional MCT8 can induce brain lesions associated with the Allan-Herndon-Dudley syndrome, characterized by psychomotor retardation. We used the layered chicken optic tectum to model cortical development, and induced MCT8 deficiency in neural progenitors. Impaired cell proliferation, migration, and differentiation resulted in an underdeveloped optic tectum and a severe reduction in nerve cells. Our data underline the need for MCT8-dependent TH uptake in neural progenitors and stress the importance of local TH action in early development.
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32
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Syed MH, Mark B, Doe CQ. Playing Well with Others: Extrinsic Cues Regulate Neural Progenitor Temporal Identity to Generate Neuronal Diversity. Trends Genet 2017; 33:933-942. [PMID: 28899597 DOI: 10.1016/j.tig.2017.08.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2017] [Revised: 08/18/2017] [Accepted: 08/18/2017] [Indexed: 11/27/2022]
Abstract
During neurogenesis, vertebrate and Drosophila progenitors change over time as they generate a diverse population of neurons and glia. Vertebrate neural progenitors have long been known to use both progenitor-intrinsic and progenitor-extrinsic cues to regulate temporal patterning. In contrast, virtually all temporal patterning mechanisms discovered in Drosophila neural progenitors (neuroblasts) involve progenitor-intrinsic temporal transcription factor cascades. Recent results, however, have revealed several extrinsic pathways that regulate Drosophila neuroblast temporal patterning: nutritional cues regulate the timing of neuroblast proliferation/quiescence and a steroid hormone cue that is required for temporal transcription factor expression. Here, we discuss newly discovered extrinsic cues regulating neural progenitor temporal identity in Drosophila, highlight conserved mechanisms, and raise open questions for the future.
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Affiliation(s)
- Mubarak Hussain Syed
- Institute of Neuroscience, Institute of Molecular Biology, Howard Hughes Medical Institute, University of Oregon, Eugene, OR 97403, USA
| | - Brandon Mark
- Institute of Neuroscience, Institute of Molecular Biology, Howard Hughes Medical Institute, University of Oregon, Eugene, OR 97403, USA
| | - Chris Q Doe
- Institute of Neuroscience, Institute of Molecular Biology, Howard Hughes Medical Institute, University of Oregon, Eugene, OR 97403, USA.
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33
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Mengeling BJ, Wei Y, Dobrawa LN, Streekstra M, Louisse J, Singh V, Singh L, Lein PJ, Wulff H, Murk AJ, Furlow JD. A multi-tiered, in vivo, quantitative assay suite for environmental disruptors of thyroid hormone signaling. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2017; 190:1-10. [PMID: 28662416 PMCID: PMC5558850 DOI: 10.1016/j.aquatox.2017.06.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 06/18/2017] [Accepted: 06/20/2017] [Indexed: 06/07/2023]
Abstract
The essential role of thyroid hormone (TH) signaling in mammalian development warrants the examination of man-made chemicals for its disruption. Among vertebrate species, the molecular components of TH signaling are highly conserved, including the thyroid hormone receptors (TRs), their heterodimer binding partners the retinoid-X receptors (RXRs), and their DNA recognition sequences (TREs). This molecular conservation allows examination of potential TH disruption in the tractable, in vivo model system of amphibian metamorphosis. Metamorphosis requires TH signaling for both instigation and progression, and it provides dramatic and well-characterized phenotypes involving different cell fates. Here we describe a quantitative, precocious-metamorphosis assay suite we developed using one-week post-fertilization (PF) Xenopus laevis tadpoles in order to assess disruption of TH signaling. Tadpoles at this developmental stage (Nieuwkoop-Faber (NF)-48) are competent to respond to TH hormone, although not yet producing TH, along many metamorphic pathways, and they are uniform in size. This allowed us to quantify changes in morphology associated with natural metamorphosis (e.g. gill and tail resorption, brain expansion, and craniofacial remodeling) after five days of treatment. Using the same tadpoles from morphological measurements, we quantified a 20-fold increase in TH-induced cellular proliferation in the rostral head region by whole-mount immunocytochemistry. At the molecular level, we used F3-generation tadpoles from a transgenic X. laevis line, which expresses luciferase under the control of a native TRE, to assess the ability of compounds to disrupt TR function. The luciferase reporter showed over 10-fold activation by physiologic concentrations of TH. We used the synthetic TR antagonist NH-3 to demonstrate the feasibility of our assay suite to measure inhibition of TH activity at the level of the receptor. Finally, we assessed the capabilities of suspected TH-disrupting chemicals tetrabrominated diphenyl ether 47 (BDE-47) and tetrabromobisphenol A (TBBPA). We found that BDE-47 displays general toxicity rather than TH disruption, as it did not increase brain width nor affect the TRE-luciferase reporter. However, TBBPA, a suspected TR antagonist, although not effective in antagonizing cell proliferation, significantly inhibited the TRE-luciferase reporter, suggesting that it bears closer scrutiny as a TH disruptor. Overall the assay suite has important advantages over the classical tadpole metamorphosis assays with respect to the uniformity of animal size, small test volume, reproducibility, and short test period. The assays are performed before endogenous TH production and free feeding start, which further reduces complexity and variability.
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Affiliation(s)
- Brenda J Mengeling
- Department of Neurobiology, Physiology, and Behavior, College of Biological Sciences, University of California, Davis 95616-8519, USA
| | - Yuzhu Wei
- Marine Animal Ecology Group, Wageningen University, The Netherlands, Wageningen University, P.O. Box 38, 6700 AH Wageningen, The Netherlands
| | - Lucia N Dobrawa
- Department of Neurobiology, Physiology, and Behavior, College of Biological Sciences, University of California, Davis 95616-8519, USA
| | - Mischa Streekstra
- Marine Animal Ecology Group, Wageningen University, The Netherlands, Wageningen University, P.O. Box 38, 6700 AH Wageningen, The Netherlands
| | - Jochem Louisse
- Division of Toxicology, Wageningen University, The Netherlands, Wageningen University, P.O. Box 8000, 6700 EA Wageningen, The Netherlands
| | - Vikrant Singh
- Department of Pharmacology, School of Medicine, University of California, Davis, CA 95616, USA
| | - Latika Singh
- Department of Pharmacology, School of Medicine, University of California, Davis, CA 95616, USA
| | - Pamela J Lein
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
| | - Heike Wulff
- Department of Pharmacology, School of Medicine, University of California, Davis, CA 95616, USA
| | - Albertinka J Murk
- Marine Animal Ecology Group, Wageningen University, The Netherlands, Wageningen University, P.O. Box 38, 6700 AH Wageningen, The Netherlands
| | - J David Furlow
- Department of Neurobiology, Physiology, and Behavior, College of Biological Sciences, University of California, Davis 95616-8519, USA.
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34
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Sachs LM, Buchholz DR. Frogs model man: In vivo thyroid hormone signaling during development. Genesis 2017; 55. [PMID: 28109053 DOI: 10.1002/dvg.23000] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 11/14/2016] [Accepted: 11/16/2016] [Indexed: 12/25/2022]
Abstract
Thyroid hormone (TH) signaling comprises TH transport across cell membranes, metabolism by deiodinases, and molecular mechanisms of gene regulation. Proper TH signaling is essential for normal perinatal development, most notably for neurogenesis and fetal growth. Knowledge of perinatal TH endocrinology needs improvement to provide better treatments for premature infants and endocrine diseases during gestation and to counteract effects of endocrine disrupting chemicals. Studies in amphibians have provided major insights to understand in vivo mechanisms of TH signaling. The frog model boasts dramatic TH-dependent changes directly observable in free-living tadpoles with precise and easy experimental control of the TH response at developmental stages comparable to fetal stages in mammals. The hormones, their receptors, molecular mechanisms, and developmental roles of TH signaling are conserved to a high degree in humans and amphibians, such that with respect to developmental TH signaling "frogs are just little people that hop." The frog model is exceptionally illustrative of fundamental molecular mechanisms of in vivo TH action involving TH receptors, transcriptional cofactors, and chromatin remodeling. This review highlights the current need, recent successes, and future prospects using amphibians as a model to elucidate molecular mechanisms and functional roles of TH signaling during post-embryonic development.
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Affiliation(s)
- Laurent M Sachs
- UMR 7221 CNRS, Muséum National d'histoire Naturelle, Dépt. Régulation, Développement et Diversité Moléculaire, Sorbonne Universités, Paris, 75005, France
| | - Daniel R Buchholz
- Department of Biological Sciences, University of Cincinnati, Cincinnati, Ohio, 45221
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Sex Differences in Brain Thyroid Hormone Levels during Early Post-Hatching Development in Zebra Finch (Taeniopygia guttata). PLoS One 2017; 12:e0169643. [PMID: 28060907 PMCID: PMC5218492 DOI: 10.1371/journal.pone.0169643] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Accepted: 12/20/2016] [Indexed: 11/19/2022] Open
Abstract
Thyroid hormones are closely linked to the hatching process in precocial birds. Previously, we showed that thyroid hormones in brain had a strong impact on filial imprinting, an early learning behavior in newly hatched chicks; brain 3,5,3'-triiodothyronine (T3) peaks around hatching and imprinting training induces additional T3 release, thus, extending the sensitive period for imprinting and enabling subsequent other learning. On the other hand, blood thyroid hormone levels have been reported to increase gradually after hatching in altricial species, but it remains unknown how the brain thyroid hormone levels change during post-hatching development of altricial birds. Here, we determined the changes in serum and brain thyroid hormone levels of a passerine songbird species, the zebra finch using radioimmunoassay. In the serum, we found a gradual increase in thyroid hormone levels during post-hatching development, as well as differences between male and female finches. In the brain, there was clear surge in the hormone levels during development in males and females coinciding with the time of fledging, but the onset of the surge of thyroxine (T4) in males preceded that of females, whereas the onset of the surge of T3 in males succeeded that of females. These findings provide a basis for understanding the functions of thyroid hormones during early development and learning in altricial birds.
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McKeown CR, Thompson CK, Cline HT. Reversible developmental stasis in response to nutrient availability in the Xenopus laevis central nervous system. ACTA ACUST UNITED AC 2016; 220:358-368. [PMID: 27875263 DOI: 10.1242/jeb.151043] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 11/04/2016] [Indexed: 12/31/2022]
Abstract
Many organisms confront intermittent nutrient restriction (NR), but the mechanisms to cope with nutrient fluctuations during development are not well understood. This is particularly true of the brain, the development and function of which is energy intensive. Here we examine the effects of nutrient availability on visual system development in Xenopus laevis tadpoles. During the first week of development, tadpoles draw nutrients from maternally provided yolk. Upon yolk depletion, animals forage for food. By altering access to external nutrients after yolk depletion, we identified a period of reversible stasis during tadpole development. We demonstrate that NR results in developmental stasis characterized by a decrease in overall growth of the animals, a failure to progress through developmental stages, and a decrease in volume of the optic tectum. During NR, neural progenitors virtually cease proliferation, but tadpoles swim and behave normally. Introducing food after temporary NR increased neural progenitor cell proliferation more than 10-fold relative to NR tadpoles, and cell proliferation was comparable to that of fed counterparts 1 week after delayed feeding. Delayed feeding also rescued NR-induced body length and tectal volume deficits and partially rescued developmental progression defects. Tadpoles recover from developmental stasis if food is provided within the first 9 days of NR, after which access to food fails to increase cell proliferation. These results show that early stages of tadpole brain development are acutely sensitive to fluctuations in nutrient availability and that NR induces developmental stasis from which animals can recover if food becomes available within a critical window.
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Affiliation(s)
- C R McKeown
- Department of Molecular and Cellular Neuroscience, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - C K Thompson
- Department of Molecular and Cellular Neuroscience, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - H T Cline
- Department of Molecular and Cellular Neuroscience, The Scripps Research Institute, La Jolla, CA 92037, USA
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