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Li Y, Cai T, Liu H, Liu J, Chen SY, Fan H. Exosome-shuttled miR-126 mediates ethanol-induced disruption of neural crest cell-placode cell interaction by targeting SDF1. Toxicol Sci 2023; 195:184-201. [PMID: 37490477 PMCID: PMC10801442 DOI: 10.1093/toxsci/kfad068] [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] [Indexed: 07/27/2023] Open
Abstract
During embryonic development, 2 populations of multipotent stem cells, cranial neural crest cells (NCCs) and epibranchial placode cells (PCs), are anatomically adjacent to each other. The coordinated migration of NCCs and PCs plays a major role in the morphogenesis of craniofacial skeletons and cranial nerves. It is known that ethanol-induced dysfunction of NCCs and PCs is a key contributor to the defects of craniofacial skeletons and cranial nerves implicated in fetal alcohol spectrum disorder (FASD). However, how ethanol disrupts the coordinated interaction between NCCs and PCs was not elucidated. To fill in this gap, we established a well-designed cell coculture system to investigate the reciprocal interaction between human NCCs (hNCCs) and human PCs (hPCs), and also monitored the migration behavior of NCCs and PCs in zebrafish embryos. We found that ethanol exposure resulted in a disruption of coordinated hNCCs-hPCs interaction, as well as in zebrafish embryos. Treating hNCCs-hPCs with exosomes derived from ethanol-exposed hNCCs (ExoEtOH) mimicked ethanol-induced impairment of hNCCs-hPCs interaction. We also observed that SDF1, a chemoattractant, was downregulated in ethanol-treated hPCs and zebrafish embryos. Meanwhile, miR-126 level in ExoEtOH was significantly higher than that in control exosomes (ExoCon). We further validated that ExoEtOH-encapsulated miR-126 from hNCCs can be transferred to hPCs to suppress SDF1 expression in hPCs. Knockdown of SDF1 replicated ethanol-induced abnormalities either in vitro or in zebrafish embryos. On the contrary, overexpression of SDF1 or inhibiting miR-126 strongly rescued ethanol-induced impairment of hNCCs-hPCs interaction and developmental defects.
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Affiliation(s)
- Yihong Li
- Ningbo No.2 Hospital, Ningbo 315099, China
- Ningbo Institute of Life and Health Industry, University of Chinese Academy of Sciences, Ningbo 315000, China
- Lab of Nanopharmacology Research for Neurodegeneration, Department of Research and Development of Science and Technology, Ningbo Institute of Life and Health Industry, University of Chinese Academy of Sciences, Ningbo, Zhejiang Province 315000, China
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, Kentucky 40292, USA
| | - Ting Cai
- Ningbo No.2 Hospital, Ningbo 315099, China
- Ningbo Institute of Life and Health Industry, University of Chinese Academy of Sciences, Ningbo 315000, China
| | - Huina Liu
- Ningbo No.2 Hospital, Ningbo 315099, China
- Ningbo Institute of Life and Health Industry, University of Chinese Academy of Sciences, Ningbo 315000, China
| | - Jie Liu
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, Kentucky 40292, USA
| | - Shao-Yu Chen
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, Kentucky 40292, USA
| | - Huadong Fan
- Ningbo No.2 Hospital, Ningbo 315099, China
- Ningbo Institute of Life and Health Industry, University of Chinese Academy of Sciences, Ningbo 315000, China
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, Kentucky 40292, USA
- Lab of Dementia and Neurorehabilitation Research, Department of Research and Development of Science and Technology, Ningbo Institute of Life and Health Industry, University of Chinese Academy of Sciences, Ningbo, Zhejiang Province 315000, China
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2
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Gamage TKJB, Fraser M. The Role of Extracellular Vesicles in the Developing Brain: Current Perspective and Promising Source of Biomarkers and Therapy for Perinatal Brain Injury. Front Neurosci 2021; 15:744840. [PMID: 34630028 PMCID: PMC8498217 DOI: 10.3389/fnins.2021.744840] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 08/23/2021] [Indexed: 12/12/2022] Open
Abstract
This comprehensive review focuses on our current understanding of the proposed physiological and pathological functions of extracellular vesicles (EVs) in the developing brain. Furthermore, since EVs have attracted great interest as potential novel cell-free therapeutics, we discuss advances in the knowledge of stem cell- and astrocyte-derived EVs in relation to their potential for protection and repair following perinatal brain injury. This review identified 13 peer-reviewed studies evaluating the efficacy of EVs in animal models of perinatal brain injury; 12/13 utilized mesenchymal stem cell-derived EVs (MSC-EVs) and 1/13 utilized astrocyte-derived EVs. Animal model, method of EV isolation and size, route, timing, and dose administered varied between studies. Notwithstanding, EV treatment either improved and/or preserved perinatal brain structures both macroscopically and microscopically. Additionally, EV treatment modulated inflammatory responses and improved brain function. Collectively this suggests EVs can ameliorate, or repair damage associated with perinatal brain injury. These findings warrant further investigation to identify the optimal cell numbers, source, and dosage regimens of EVs, including long-term effects on functional outcomes.
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Affiliation(s)
- Teena K J B Gamage
- Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Mhoyra Fraser
- Department of Physiology, The University of Auckland, Auckland, New Zealand
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3
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Vierl F, Kaur M, Götz M. Non-codon Optimized PiggyBac Transposase Induces Developmental Brain Aberrations: A Call for in vivo Analysis. Front Cell Dev Biol 2021; 9:698002. [PMID: 34414186 PMCID: PMC8369470 DOI: 10.3389/fcell.2021.698002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 07/14/2021] [Indexed: 11/13/2022] Open
Abstract
In this perspective article, we briefly review tools for stable gain-of-function expression to explore key fate determinants in embryonic brain development. As the piggyBac transposon system has the highest insert size, a seamless integration of the transposed sequence into the host genome, and can be delivered by transfection avoiding viral vectors causing an immune response, we explored its use in the murine developing forebrain. The original piggyBac transposase PBase or the mouse codon-optimized version mPB and the construct to insert, contained in the piggyBac transposon, were introduced by in utero electroporation at embryonic day 13 into radial glia, the neural stem cells, in the developing dorsal telencephalon, and analyzed 3 or 5 days later. When using PBase, we observed an increase in basal progenitor cells, often accompanied by folding aberrations. These effects were considerably ameliorated when using the piggyBac plasmid together with mPB. While size and strength of the electroporated region was not correlated to the aberrations, integration was essential and the positive correlation to the insert size implicates the frequency of transposition as a possible mechanism. We discuss this in light of the increase in transposing endogenous viral vectors during mammalian phylogeny and their role in neurogenesis and radial glial cells. Most importantly, we aim to alert the users of this system to the phenotypes caused by non-codon optimized PBase application in vivo.
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Affiliation(s)
- Franziska Vierl
- Institute for Stem Cell Research, Helmholtz Zentrum München, Munich, Germany.,Physiological Genomics, Biomedical Center, Ludwig-Maximilians-Universität, Munich, Germany.,Graduate School of Systemic Neurosciences, Ludwig-Maximilians-Universität, Munich, Germany
| | - Manpreet Kaur
- Physiological Genomics, Biomedical Center, Ludwig-Maximilians-Universität, Munich, Germany
| | - Magdalena Götz
- Institute for Stem Cell Research, Helmholtz Zentrum München, Munich, Germany.,Physiological Genomics, Biomedical Center, Ludwig-Maximilians-Universität, Munich, Germany.,SyNergy, Munich Cluster for Systems Neurology, Ludwig-Maximilians-Universität, Munich, Germany
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4
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Neckles VN, Feliciano DM. From seed to flower: blossoming of microglia in development and brain repair. Cell Tissue Res 2021; 387:377-389. [PMID: 34151391 DOI: 10.1007/s00441-021-03486-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 06/09/2021] [Indexed: 12/23/2022]
Abstract
Physiological functions require coordination of processes between diverse organs, tissues, and cells. This integrative view of science has reemerged complementary to the reductionist philosophy of studying individual cell types. An integrative approach has proven particularly powerful within the field of neuroscience where, intermingled among the most numerous neural cell types of the brain, are immune cells called microglia. Microglia act as a line of defense in the CNS by phagocytizing harmful pathogens and cellular debris and by releasing a variety of factors that mediate immune responses. However, microglia are also appreciated as critical mediators of neurophysiology making them a desired target to rectify neuropathological states. The goal of this review is to discuss microglia ontogenesis, referred to as microgliogenesis, a term that encompasses the events that drive the production, differentiation, migration, and maturation of microglia and opportunities to target microglia for brain repair.
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Affiliation(s)
- Victoria N Neckles
- Department of Biological Sciences, Clemson University, Clemson, SC, 29634-0314, USA
| | - David M Feliciano
- Department of Biological Sciences, Clemson University, Clemson, SC, 29634-0314, USA.
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5
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Yeh YT, Zhou Y, Zou D, Liu H, Yu H, Lu H, Swaminathan V, Mao Y, Terrones M. Rapid Size-Based Isolation of Extracellular Vesicles by Three-Dimensional Carbon Nanotube Arrays. ACS APPLIED MATERIALS & INTERFACES 2020; 12:13134-13139. [PMID: 32073255 DOI: 10.1021/acsami.9b20990] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Recent discoveries reveal that extracellular vesicles (EVs) play an important role in transmitting signals. Although this emerging transcellular pathway enables a better understanding of neural communication, the lack of techniques for effectively isolating EVs impedes their studies. Herein, we report an emergent high-throughput platform consisting of three-dimensional carbon nanotube arrays that rapidly capture different EVs based on their sizes, without any labels. More importantly, this label-free capture maintains the integrity of the EVs when they are excreted from a host cell, thus allowing comprehensive downstream analyses using conventional approaches. To study neural communication, we developed a stamping technique to construct a gradient of nanotube herringbone arrays and integrated them into a microdevice that allowed us processing of a wide range of sample volumes, microliters to milliliters, in several minutes through a syringe via manual hand pushing and without any sample preparation. This microdevice successfully captured and separated EVs excreted from glial cells into subgroups according to their sizes. During capture, this technology preserved the structural integrity and originality of the EVs that enabled us to monitor and follow internalization of EVs of different sizes by neurons and cells. As a proof of concept, our results showed that smaller EVs (∼80 nm in diameter) have a higher uptake efficiency compared to larger EVs (∼300 nm in diameter). In addition, after being internalized, small EVs could enter endoplasmic reticulum and Golgi but not the largest ones. Our platform significantly shortens sample preparation, allows the profiling of the different EVs based on their size, and facilitates the understanding of extracellular communication. Thus, it leads to early diagnostics and the development of novel therapeutics for neurological diseases.
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Affiliation(s)
- Yin-Ting Yeh
- Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Material Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Yijing Zhou
- The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Department of Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Donghua Zou
- Department of Neurology, The Fifth Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530022, China
| | - He Liu
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Haiyang Yu
- Department of Veterinary and Biomedical Science, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Huaguang Lu
- Department of Veterinary and Biomedical Science, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Venkataraman Swaminathan
- Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Yingwei Mao
- The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Department of Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Mauricio Terrones
- Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Material Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Department of Materials Science & Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
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6
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Morton MC, Neckles VN, Seluzicki CM, Holmberg JC, Feliciano DM. Neonatal Subventricular Zone Neural Stem Cells Release Extracellular Vesicles that Act as a Microglial Morphogen. Cell Rep 2019; 23:78-89. [PMID: 29617675 DOI: 10.1016/j.celrep.2018.03.037] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 02/19/2018] [Accepted: 03/09/2018] [Indexed: 02/06/2023] Open
Abstract
Subventricular zone (SVZ) neural stem cells (NSCs) are the cornerstone of the perinatal neurogenic niche. Microglia are immune cells of the nervous system that are enriched in the neonatal SVZ. Although microglia regulate NSCs, the extent to which this interaction is bi-directional is unclear. Extracellular vesicles (EVs) are cell-derived particles that encase miRNA and proteins. Here, we demonstrate that SVZ NSCs generate and release EVs. Neonatal electroporated fluorescent EV fusion proteins were released by NSCs and subsequently cleared from the SVZ. EVs were preferentially targeted to microglia. Small RNA sequencing identified miRNAs within the EVs that regulate microglia physiology and morphology. EVs induced a transition to a CD11b/Iba1 non-stellate microglial morphology. The transition accompanied a microglial transcriptional state characterized by Let-7-regulated cytokine release and a negative feedback loop that controlled NSC proliferation. These findings implicate an NSC-EV-microglia axis and provide insight to normal and pathophysiological brain development.
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Affiliation(s)
- Mary C Morton
- Department of Biological Sciences, Clemson University, Clemson, SC 29634-0314, USA
| | - Victoria N Neckles
- Department of Biological Sciences, Clemson University, Clemson, SC 29634-0314, USA
| | - Caitlin M Seluzicki
- Department of Biological Sciences, Clemson University, Clemson, SC 29634-0314, USA
| | - Jennie C Holmberg
- Department of Biological Sciences, Clemson University, Clemson, SC 29634-0314, USA
| | - David M Feliciano
- Department of Biological Sciences, Clemson University, Clemson, SC 29634-0314, USA.
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7
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Neckles VN, Morton MC, Holmberg JC, Sokolov AM, Nottoli T, Liu D, Feliciano DM. A transgenic inducible GFP extracellular-vesicle reporter (TIGER) mouse illuminates neonatal cortical astrocytes as a source of immunomodulatory extracellular vesicles. Sci Rep 2019; 9:3094. [PMID: 30816224 PMCID: PMC6395689 DOI: 10.1038/s41598-019-39679-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Accepted: 01/29/2019] [Indexed: 01/01/2023] Open
Abstract
Extracellular vesicles (EVs) are cellular derived particles found throughout the body in nearly all tissues and bodily fluids. EVs contain biological molecules including small RNAs and protein. EVs are proposed to be transferred between cells, notably, cells of the immune system. Tools that allow for in vivo EV labeling while retaining the ability to resolve cellular sources and timing of release are required for a full understanding of EV functions. Fluorescent EV fusion proteins are useful for the study of EV biogenesis, release, and identification of EV cellular recipients. Among the most plentiful and frequently identified EV proteins is CD9, a tetraspanin protein. A transgenic mouse containing a CRE-recombinase inducible CAG promoter driven CD9 protein fused to Turbo-GFP derived from the copepod Pontellina plumata was generated as an EV reporter. The transgenic inducible GFP EV reporter (TIGER) mouse was electroporated with CAG-CRE plasmids or crossed with tamoxifen inducible CAG-CRE-ERT2 or nestin-CRE-ERT2 mice. CD9-GFP labeled cells included glutamine synthetase and glial fibrillary acidic protein positive astrocytes. Cortical astrocytes released ~136 nm EVs that contained CD9. Intraventricular injected EVs were taken up by CD11b/IBA1 positive microglia surrounding the lateral ventricles. Neonatal electroporation and shRNA mediated knockdown of Rab27a in dorsal subventricular zone NSCs and astrocytes increased the number of CD11b/IBA1 positive rounded microglia. Neonatal astrocyte EVs had a unique small RNA signature comprised of morphogenic miRNAs that induce microglia cytokine release. The results from this study demonstrate that inducible CD9-GFP mice will provide the EV community with a tool that allows for EV labeling in a cell-type specific manner while simultaneously allowing in vivo experimentation and provides evidence that EVs are required immunomodulators of the developing nervous system.
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Affiliation(s)
- Victoria N Neckles
- Department of Biological Sciences, Clemson University, Clemson, SC, 29634-0314, USA
| | - Mary C Morton
- Department of Biological Sciences, Clemson University, Clemson, SC, 29634-0314, USA
| | - Jennie C Holmberg
- Department of Biological Sciences, Clemson University, Clemson, SC, 29634-0314, USA
| | - Aidan M Sokolov
- Department of Biological Sciences, Clemson University, Clemson, SC, 29634-0314, USA
| | - Timothy Nottoli
- Yale Genome Editing Center, Department of Comparative Medicine, Yale School of Medicine, PO Box 208016, New Haven, CT, 06520-8016, USA
| | - Don Liu
- Charles River Laboratories, 261 Ballardvale Street, Wilmington, MA, 01887, USA
| | - David M Feliciano
- Department of Biological Sciences, Clemson University, Clemson, SC, 29634-0314, USA.
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8
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Ramirez SH, Andrews AM, Paul D, Pachter JS. Extracellular vesicles: mediators and biomarkers of pathology along CNS barriers. Fluids Barriers CNS 2018; 15:19. [PMID: 29960602 PMCID: PMC6026502 DOI: 10.1186/s12987-018-0104-7] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 05/28/2018] [Indexed: 02/07/2023] Open
Abstract
Extracellular vesicles (EVs) are heterogeneous, nano-sized vesicles that are shed into the blood and other body fluids, which disperse a variety of bioactive molecules (e.g., protein, mRNA, miRNA, DNA and lipids) to cellular targets over long and short distances. EVs are thought to be produced by nearly every cell type, however this review will focus specifically on EVs that originate from cells at the interface of CNS barriers. Highlighted topics include, EV biogenesis, the production of EVs in response to neuroinflammation, role in intercellular communication and their utility as a therapeutic platform. In this review, novel concepts regarding the use of EVs as biomarkers for BBB status and as facilitators for immune neuroinvasion are also discussed. Future directions and prospective are covered along with important unanswered questions in the field of CNS endothelial EV biology.
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Affiliation(s)
- Servio H Ramirez
- Department of Pathology and Laboratory Medicine, The Lewis Katz School of Medicine at Temple University, 3500 N Broad St, Philadelphia, PA, 19140, USA. .,Shriners Hospital Pediatric Research Center, Philadelphia, PA, 19140, USA. .,Center for Substance Abuse Research, The Lewis Katz School of Medicine at Temple University, Philadelphia, PA, 19140, USA.
| | - Allison M Andrews
- Department of Pathology and Laboratory Medicine, The Lewis Katz School of Medicine at Temple University, 3500 N Broad St, Philadelphia, PA, 19140, USA.,Center for Substance Abuse Research, The Lewis Katz School of Medicine at Temple University, Philadelphia, PA, 19140, USA
| | - Debayon Paul
- Department of Immunology, Blood-Brain Barrier Laboratory & Laser Capture Microdissection Core, UConn Health, 263 Farmington Ave., Farmington, CT, 06070, USA
| | - Joel S Pachter
- Department of Immunology, Blood-Brain Barrier Laboratory & Laser Capture Microdissection Core, UConn Health, 263 Farmington Ave., Farmington, CT, 06070, USA.
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9
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Ockleford C, Adriaanse P, Hougaard Bennekou S, Berny P, Brock T, Duquesne S, Grilli S, Hernandez-Jerez AF, Klein M, Kuhl T, Laskowski R, Machera K, Pelkonen O, Pieper S, Smith R, Stemmer M, Sundh I, Teodorovic I, Tiktak A, Topping CJ, Gundert-Remy U, Kersting M, Waalkens-Berendsen I, Chiusolo A, Court Marques D, Dujardin B, Kass GEN, Mohimont L, Nougadère A, Reich H, Wolterink G. Scientific opinion on pesticides in foods for infants and young children. EFSA J 2018; 16:e05286. [PMID: 32625927 PMCID: PMC7009577 DOI: 10.2903/j.efsa.2018.5286] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Following a request from the European Commission, the EFSA Panel on Plant Protection Products and their Residues (PPR Panel) prepared a scientific opinion to provide a comprehensive evaluation of pesticide residues in foods for infants and young children. In its approach to develop this scientific opinion, the EFSA PPR Panel took into account, among the others, (i) the relevant opinions of the Scientific Committee for Food setting a default maximum residue level (MRL) of 0.01 mg/kg for pesticide residues in foods for infants and young children; (ii) the recommendations provided by EFSA Scientific Committee in a guidance on risk assessment of substances present in food intended for infants below 16 weeks of age; (iii) the knowledge on organ/system development in infants and young children. For infants below 16 weeks of age, the EFSA PPR Panel concluded that pesticide residues at the default MRL of 0.01 mg/kg for food for infants and young children are not likely to result in an unacceptable exposure for active substances for which a health-based guidance value (HBGV) of 0.0026 mg/kg body weight (bw) per day or higher applies. Lower MRLs are recommended for active substances with HBGVs below this value. For infants above 16 weeks of age and young children, the established approach for setting HBGVs is considered appropriate. For infants below 16 weeks of age the approach may not be appropriate and the application of the EFSA guidance on risk assessment of substances present in food intended for infants below 16 weeks of age is recommended. The contribution of conventional food to the total exposure to pesticide residues is much higher than that from foods intended for infants and young children. Because of the increased intake of conventional food by young children, these have the highest exposure to pesticide residues, whereas infants 3-6 months of age generally have lower exposure. The impact of cumulative exposure to pesticide residues on infants and young children is not different from the general population and the EFSA cumulative risk assessment methodology is also applicable to these age groups. Residue definitions established under Regulation (EC) No 396/2005 are in general considered appropriate also for foods for infants and young children. However, based on a tier 1 analysis of the hydrolysis potential of pesticides simulating processing, the particular appropriateness of existing residue definitions for monitoring to cover processed food, both intended for infants and young children as well as conventional food, is questionable.
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10
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Brégère C, Fisch U, Sailer MH, Lieb WS, Chicha L, Goepfert F, Kremer T, Guzman R. Neonatal hypoxia-ischemia in rat increases doublecortin concentration in the cerebrospinal fluid. Eur J Neurosci 2017; 46:1758-1767. [PMID: 28548285 DOI: 10.1111/ejn.13612] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 05/18/2017] [Accepted: 05/22/2017] [Indexed: 11/27/2022]
Abstract
Doublecortin (DCX) is a microtubule-associated protein widely used as an indicator of neurogenesis in immunohistochemical analyses of the postmortem adult brain. A recent study reported that DCX can be quantified in the cerebrospinal fluid (CSF) from healthy rats between postnatal day 0 (P0) and P30. However, it is currently unclear whether the concentration of DCX in the CSF (CSF-DCX) may represent a measure of endogenous neurogenesis. To address this question, this study examined the impact of a neonatal hypoxic-ischemic (HI) brain injury, known to induce neurogenesis, on CSF-DCX. HI was elicited at P7 in Sprague-Dawley rat neonates, and CSF was collected serially from the cisterna magna at P5 and P10, or at P10 and P15. A sandwich immunoassay was used to measure CSF-DCX. Brains from P10 neonates were analyzed immunohistochemically for neurogenesis and cell death markers. Mean CSF-DCX was significantly higher in HI- than in sham-exposed animals, at both P10 and P15. In the HI group at P10, CSF-DCX and stroke severity correlated positively. DCX immunoreactivity was increased in the ipsilateral neurogenic niches from the P10 HI brains in comparison with that of shams. The number of proliferative DCX-positive cells was higher in the ipsilateral hippocampal subgranular zone (SGZ) than in the HI contralateral or sham SGZ. Thus, neonatal HI brain injury disrupts the developmental time-course of DCX levels in the CSF. Our data suggest that the increased concentration of DCX in the CSF after neonatal HI is the result of both cellular injury and increased neurogenesis.
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Affiliation(s)
- Catherine Brégère
- Brain Ischemia and Regeneration, Department of Biomedicine and Department of Neurosurgery, University Hospital Basel, Basel, Switzerland
| | - Urs Fisch
- Brain Ischemia and Regeneration, Department of Biomedicine and Department of Neurosurgery, University Hospital Basel, Basel, Switzerland
| | | | - Wolfgang S Lieb
- Brain Ischemia and Regeneration, Department of Biomedicine and Department of Neurosurgery, University Hospital Basel, Basel, Switzerland
| | - Laurie Chicha
- Brain Ischemia and Regeneration, Department of Biomedicine and Department of Neurosurgery, University Hospital Basel, Basel, Switzerland
| | - Fabienne Goepfert
- Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Thomas Kremer
- Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Raphael Guzman
- Brain Ischemia and Regeneration, Department of Biomedicine and Department of Neurosurgery, University Hospital Basel, Basel, Switzerland
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