1
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Chen HJC, Mazzaferro S, Tian T, Mali I, Merkle FT. Differentiation, Transcriptomic Profiling, and Calcium Imaging of Human Hypothalamic Neurons. Curr Protoc 2023; 3:e786. [PMID: 37272700 PMCID: PMC7614736 DOI: 10.1002/cpz1.786] [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: 06/06/2023]
Abstract
Neurons in the hypothalamus orchestrate homeostatic physiological processes and behaviors essential for life. Human pluripotent stem cells (hPSCs) can be differentiated into many types of hypothalamic neurons, progenitors, and glia. This updated unit includes published studies and protocols with new advances in the differentiation, maturation, and interrogation by transcriptomic profiling and calcium imaging of human hypothalamic cell populations. Specifically, new methods to freeze and thaw hypothalamic progenitors after they have been patterned and before substantial neurogenesis has occurred are provided that will facilitate experimental flexibility and planning. Also included are updated recipes and protocols for neuronal maturation, with details on the equipment and methods for examining their transcriptomic response and cell-autonomous properties in culture in the presence of synaptic blockers. Together, these protocols facilitate the adoption and use of this model system for fundamental biological discovery and therapeutic translation to human diseases such as obesity, diabetes, sleep disorders, infertility, and chronic stress. © 2023 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: hPSC maintenance Basic Protocol 2: Hypothalamic neuron differentiation Support Protocol 1: Cortical neuron (control) differentiation Basic Protocol 3: Neuronal maturation Support Protocol 2: Cryopreservation and thawing of neuronal progenitors Support Protocol 3: Quality control: Confirmation of hypothalamic patterning and neurogenesis Support Protocol 4: Bulk RNA sequencing of hypothalamic cultures Basic Protocol 4: Calcium imaging of hypothalamic neurons using Fura-2 AM Alternate Protocol: Calcium imaging of green fluorescent hypothalamic neurons using Rhod-3 AM.
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Affiliation(s)
- Hsiao-Jou Cortina Chen
- Metabolic Research Laboratories, Wellcome Trust MRC Institute of Metabolic Science, University of Cambridge, Addenbrooke’s Hospital, Cambridge, UK
- Wellcome Trust–Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
| | - Simone Mazzaferro
- Metabolic Research Laboratories, Wellcome Trust MRC Institute of Metabolic Science, University of Cambridge, Addenbrooke’s Hospital, Cambridge, UK
- Wellcome Trust–Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
| | - Tian Tian
- Metabolic Research Laboratories, Wellcome Trust MRC Institute of Metabolic Science, University of Cambridge, Addenbrooke’s Hospital, Cambridge, UK
- Wellcome Trust–Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
| | - Iman Mali
- Metabolic Research Laboratories, Wellcome Trust MRC Institute of Metabolic Science, University of Cambridge, Addenbrooke’s Hospital, Cambridge, UK
| | - Florian T. Merkle
- Metabolic Research Laboratories, Wellcome Trust MRC Institute of Metabolic Science, University of Cambridge, Addenbrooke’s Hospital, Cambridge, UK
- Wellcome Trust–Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
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2
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Patel T, Hammelman J, Aziz S, Jang S, Closser M, Michaels TL, Blum JA, Gifford DK, Wichterle H. Transcriptional dynamics of murine motor neuron maturation in vivo and in vitro. Nat Commun 2022; 13:5427. [PMID: 36109497 PMCID: PMC9477853 DOI: 10.1038/s41467-022-33022-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 08/25/2022] [Indexed: 12/03/2022] Open
Abstract
Neurons born in the embryo can undergo a protracted period of maturation lasting well into postnatal life. How gene expression changes are regulated during maturation and whether they can be recapitulated in cultured neurons remains poorly understood. Here, we show that mouse motor neurons exhibit pervasive changes in gene expression and accessibility of associated regulatory regions from embryonic till juvenile age. While motifs of selector transcription factors, ISL1 and LHX3, are enriched in nascent regulatory regions, motifs of NFI factors, activity-dependent factors, and hormone receptors become more prominent in maturation-dependent enhancers. Notably, stem cell-derived motor neurons recapitulate ~40% of the maturation expression program in vitro, with neural activity playing only a modest role as a late-stage modulator. Thus, the genetic maturation program consists of a core hardwired subprogram that is correctly executed in vitro and an extrinsically-controlled subprogram that is dependent on the in vivo context of the maturing organism.
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Affiliation(s)
- Tulsi Patel
- Departments of Pathology & Cell Biology, Neuroscience, and Neurology, Columbia University Irving Medical Center, New York, NY, 10032, USA.
| | - Jennifer Hammelman
- Computer Science and Artificial Intelligence Laboratory, MIT, Cambridge, MA, 02139, USA
| | - Siaresh Aziz
- Departments of Pathology & Cell Biology, Neuroscience, and Neurology, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Sumin Jang
- Departments of Pathology & Cell Biology, Neuroscience, and Neurology, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Michael Closser
- Departments of Pathology & Cell Biology, Neuroscience, and Neurology, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Theodore L Michaels
- Departments of Pathology & Cell Biology, Neuroscience, and Neurology, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Jacob A Blum
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - David K Gifford
- Computer Science and Artificial Intelligence Laboratory, MIT, Cambridge, MA, 02139, USA
| | - Hynek Wichterle
- Departments of Pathology & Cell Biology, Neuroscience, and Neurology, Columbia University Irving Medical Center, New York, NY, 10032, USA.
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3
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Baytas O, Davidson SM, DeBerardinis RJ, Morrow EM. Mitochondrial enzyme GPT2 regulates metabolic mechanisms required for neuron growth and motor function in vivo. Hum Mol Genet 2021; 31:587-603. [PMID: 34519342 DOI: 10.1093/hmg/ddab269] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 09/06/2021] [Accepted: 09/06/2021] [Indexed: 01/10/2023] Open
Abstract
The metabolic needs for postnatal growth of the human nervous system are vast. Recessive loss-of-function mutations in the mitochondrial enzyme glutamate pyruvate transaminase 2 (GPT2) in humans cause postnatal undergrowth of brain, and cognitive and motor disability. We demonstrate that GPT2 governs critical metabolic mechanisms in neurons required for neuronal growth and survival. These metabolic processes include neuronal alanine synthesis and anaplerosis, the replenishment of tricarboxylic acid (TCA) cycle intermediates. We performed metabolomics across postnatal development in Gpt2-null mouse brain to identify the trajectory of dysregulated metabolic pathways: alterations in alanine occur earliest; followed by reduced TCA cycle intermediates and reduced pyruvate; followed by elevations in glycolytic intermediates and amino acids. Neuron-specific deletion of GPT2 in mice is sufficient to cause motor abnormalities and death pre-weaning, a phenotype identical to the germline Gpt2-null mouse. Alanine biosynthesis is profoundly impeded in Gpt2-null neurons. Exogenous alanine is necessary for Gpt2-null neuronal survival in vitro, but is not needed for Gpt2-null astrocytes. Dietary alanine supplementation in Gpt2-null mice enhances animal survival, and improves the metabolic profile of Gpt2-null brain, but does not alone appear to correct motor function. In surviving Gpt2-null animals, we observe smaller upper and lower motor neurons in vivo. We also observe selective death of lower motor neurons in vivo with worsening motor behavior with age. In conclusion, these studies of the pathophysiology of GPT2 Deficiency have identified metabolic mechanisms required for neuronal growth and that potentially underlie selective neuronal vulnerabilities in motor neurons.
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Affiliation(s)
- Ozan Baytas
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA.,Center for Translational Neuroscience, Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University, Providence, RI 02912, USA.,Neuroscience Graduate Program, Brown University, Providence, RI 02912, USA
| | - Shawn M Davidson
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08540, USA
| | - Ralph J DeBerardinis
- Department of Pediatrics, Children's Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.,Howard Hughes Medical Institute, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Eric M Morrow
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA.,Center for Translational Neuroscience, Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University, Providence, RI 02912, USA
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4
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Kim M, Park MH, Nam G, Lee M, Kang J, Song IS, Choi MK, Jin HK, Bae JS, Lim MH. A Glycosylated Prodrug to Attenuate Neuroinflammation and Improve Cognitive Deficits in Alzheimer's Disease Transgenic Mice. Mol Pharm 2020; 18:101-112. [PMID: 33241681 DOI: 10.1021/acs.molpharmaceut.0c00677] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
We report a prodrug, Glu-DAPPD, to overcome the shortcomings of an anti-neuroinflammatory molecule, N,N'-diacetyl-p-phenylenediamine (DAPPD), in biological applicability for potential therapeutic applications. We suspect that Glu-DAPPD can release DAPPD through endogenous enzymatic bioconversion. Consequently, Glu-DAPPD exhibits in vivo efficacies in alleviating neuroinflammation, reducing amyloid-β aggregate accumulation, and improving cognitive function in Alzheimer's disease transgenic mice. Our studies demonstrate that the prodrug approach is suitable and effective toward developing drug candidates against neurodegeneration.
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Affiliation(s)
- Mingeun Kim
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Min Hee Park
- KNU Alzheimer's disease Research Institute, Kyungpook National University, Daegu 41566, Republic of Korea.,Department of Physiology, School of Medicine, Kyungpook National University, Daegu 41944, Republic of Korea.,Department of Biomedical Science, BK21 Plus Kyungpook National University Biomedical Convergence Program, Kyungpook National University, Daegu 41944, Republic of Korea
| | - Geewoo Nam
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Misun Lee
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Juhye Kang
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea.,Technical Support Center, Office of Research Affairs, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Im-Sook Song
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Min-Koo Choi
- College of Pharmacy, Dankook University, Cheon-an 31116, Republic of Korea
| | - Hee Kyung Jin
- KNU Alzheimer's disease Research Institute, Kyungpook National University, Daegu 41566, Republic of Korea.,Department of Laboratory Animal Medicine, College of Veterinary Medicine, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Jae-Sung Bae
- KNU Alzheimer's disease Research Institute, Kyungpook National University, Daegu 41566, Republic of Korea.,Department of Physiology, School of Medicine, Kyungpook National University, Daegu 41944, Republic of Korea.,Department of Biomedical Science, BK21 Plus Kyungpook National University Biomedical Convergence Program, Kyungpook National University, Daegu 41944, Republic of Korea
| | - Mi Hee Lim
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
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5
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Bewicz-Binkowska D, Zgorzynska E, Dziedzic B, Walczewska A. Docosahexaenoic Acid (DHA) Inhibits FADS2 Expression in Astrocytes but Increases Survival of Neurons Co-cultured with DHA-enriched Astrocytes. INTERNATIONAL JOURNAL OF MOLECULAR AND CELLULAR MEDICINE 2020; 8:232-240. [PMID: 32489952 PMCID: PMC7241842 DOI: 10.22088/ijmcm.bums.8.3.232] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Docosahexaenoic acid (DHA), the most abundant n-3 polyunsaturated fatty acid (n-3PUFA) in the brain, has attracted great importance for a variety of neuronal functions such as signal transduction through plasma membranes, neuronal plasticity, and neuroprotection. Astrocytes that provide structural, functional, and metabolic support for neurons, express ∆6- desaturase encoded by FADS2 gene that can be, next to the plasma DHA pool, additional source of DHA in the brain. Furthermore, the genetic variations of FADS gene cluster has been found in children with developmental disorders, and are associated with cognitive functions. Since, the regulation of DHA biosynthesis in astrocytes remains poorly studied the aim of this study was to determine the effect of palmitic acid (PA), α-linolenic acid (ALA) or docosahexaenoic acid (DHA), on the transcription of FADS2 gene in astrocytes and survival of neurons challenged with oxidative compounds after co-culture with astrocytes exposed to DHA. The lipid profile in cell membranes after incubation with fatty acids was determined by gas chromatography, and FADS2 expression was analyzed using real-time PCR. The viability of neurons cocultured with PUFA-enriched astrocytes was investigated by flow cytometry after staining cells with annexin V-FITC and PI. The results showed that DHA suppressed (P <0.01), PA stimulated (P <0.01), while ALA did not change the FADS2 gene expression after 24 h incubation of astrocytes with fatty acids. Although FADS2 mRNA was down-regulated by DHA, its level in astrocytic membranes significantly increased (P <0.01). Astrocytes with DHA-enriched membrane phospholipids markedly enhanced neuronal resistance to cytotoxic compounds and neuronal survival. These results suggest that beneficial effects of supplementation with n-3 PUFA in Alzheimer disease and in psychiatric disorders is caused, in part, by increased efficacy of DHA-enriched astrocytes to protect neurons under adverse conditions in the brain.
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Affiliation(s)
| | - Emilia Zgorzynska
- Department of Cell-to-Cell Communication, Medical University of Lodz, Poland
| | - Barbara Dziedzic
- Department of Cell-to-Cell Communication, Medical University of Lodz, Poland
| | - Anna Walczewska
- Department of Cell-to-Cell Communication, Medical University of Lodz, Poland
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6
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Hoang PT, Chalif JI, Bikoff JB, Jessell TM, Mentis GZ, Wichterle H. Subtype Diversification and Synaptic Specificity of Stem Cell-Derived Spinal Interneurons. Neuron 2019; 100:135-149.e7. [PMID: 30308166 DOI: 10.1016/j.neuron.2018.09.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 07/06/2018] [Accepted: 09/09/2018] [Indexed: 12/25/2022]
Abstract
Neuronal diversification is a fundamental step in the construction of functional neural circuits, but how neurons generated from single progenitor domains acquire diverse subtype identities remains poorly understood. Here we developed an embryonic stem cell (ESC)-based system to model subtype diversification of V1 interneurons, a class of spinal neurons comprising four clades collectively containing dozens of molecularly distinct neuronal subtypes. We demonstrate that V1 subtype diversity can be modified by extrinsic signals. Inhibition of Notch and activation of retinoid signaling results in a switch to MafA clade identity and enriches differentiation of Renshaw cells, a specialized MafA subtype that mediates recurrent inhibition of spinal motor neurons. We show that Renshaw cells are intrinsically programmed to migrate to species-specific laminae upon transplantation and to form subtype-specific synapses with motor neurons. Our results demonstrate that stem cell-derived neuronal subtypes can be used to investigate mechanisms underlying neuronal subtype specification and circuit assembly.
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Affiliation(s)
- Phuong T Hoang
- Departments of Pathology and Cell Biology, Neuroscience, Rehabilitation & Regenerative Medicine, and Neurology, Center for Motor Neuron Biology and Disease, Columbia Stem Cell Initiative, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Joshua I Chalif
- Departments of Pathology and Cell Biology and Neurology, Center for Motor Neuron Biology and Disease, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Jay B Bikoff
- Departments of Neuroscience and Biochemistry and Molecular Biophysics, Columbia University Irving Medical Center, New York, NY 10032, USA; Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Thomas M Jessell
- Departments of Neuroscience and Biochemistry and Molecular Biophysics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - George Z Mentis
- Departments of Pathology and Cell Biology and Neurology, Center for Motor Neuron Biology and Disease, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Hynek Wichterle
- Departments of Pathology and Cell Biology, Neuroscience, Rehabilitation & Regenerative Medicine, and Neurology, Center for Motor Neuron Biology and Disease, Columbia Stem Cell Initiative, Columbia University Irving Medical Center, New York, NY 10032, USA.
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7
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The autophagic degradation of Cav-1 contributes to PA-induced apoptosis and inflammation of astrocytes. Cell Death Dis 2018; 9:771. [PMID: 29991726 PMCID: PMC6039485 DOI: 10.1038/s41419-018-0795-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 06/04/2018] [Accepted: 06/06/2018] [Indexed: 12/23/2022]
Abstract
The accumulation of palmitic acid (PA), implicated in obesity, can induce apoptotic cell death and inflammation of astrocytes. Caveolin-1 (Cav-1), an essential protein for astrocytes survival, can be degraded by autophagy, which is a double-edge sword that can either promote cell survival or cell death. The aim of this study was to delineate whether the autophagic degradation of Cav-1 is involved in PA-induced apoptosis and inflammation in hippocampal astrocytes. In this study we found that: (1) PA caused apoptotic death and inflammation by autophagic induction; (2) Cav-1 was degraded by PA-induced autophagy and PA induced autophagy in a Cav-1-independent manner; (3) the degradation of Cav-1 was responsible for PA-induced autophagy-dependent apoptotic cell death and inflammation; (4) chronic high-fat diet (HFD) induced Cav-1 degradation, apoptosis, autophagy, and inflammation in the hippocampal astrocytes of rats. Our results suggest that the autophagic degradation of Cav-1 contributes to PA-induced apoptosis and inflammation of astrocytes. Therefore, Cav-1 may be a potential therapeutic target for central nervous system injuries caused by PA accumulation.
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8
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Hampe AE, Li Z, Sethi S, Lein PJ, Seker E. A Microfluidic Platform to Study Astrocyte Adhesion on Nanoporous Gold Thin Films. NANOMATERIALS (BASEL, SWITZERLAND) 2018; 8:E452. [PMID: 29933551 PMCID: PMC6070884 DOI: 10.3390/nano8070452] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 06/14/2018] [Accepted: 06/16/2018] [Indexed: 12/19/2022]
Abstract
Nanoporous gold (np-Au) electrode coatings have shown improved neural electrophysiological recording fidelity in vitro, in part due to reduced surface coverage by astrocytes. This reduction in astrocytic spreading has been attributed to the influence of electrode nanostructure on focal adhesion (FA) formation. This study describes the development and use of a microfluidic flow cell for imposing controllable hydrodynamic shear on astrocytes cultured on gold surfaces of different morphologies, in order to study the influence of nanostructure on astrocyte adhesion strength as a function of np-Au electrode morphology. Astrocyte detachment (a surrogate for adhesion strength) monotonically increased as feature size was reduced from planar surfaces to np-Au, demonstrating that adhesion strength is dependent on nanostructure. Putative mechanisms responsible for this nanostructure-driven detachment phenomenon are also discussed.
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Affiliation(s)
- Alexander E Hampe
- Department of Biomedical Engineering, University of California-Davis, Davis, CA 95616, USA.
| | - Zidong Li
- Department of Biomedical Engineering, University of California-Davis, Davis, CA 95616, USA.
| | - Sunjay Sethi
- Department of Molecular Biosciences, University of California-Davis, Davis, CA 95616, USA.
| | - Pamela J Lein
- Department of Molecular Biosciences, University of California-Davis, Davis, CA 95616, USA.
| | - Erkin Seker
- Department of Electrical and Computer Engineering, University of California-Davis, Davis, CA 95616, USA.
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9
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Sun Z, Williams DJ, Xu B, Gogos JA. Altered function and maturation of primary cortical neurons from a 22q11.2 deletion mouse model of schizophrenia. Transl Psychiatry 2018; 8:85. [PMID: 29666363 PMCID: PMC5904157 DOI: 10.1038/s41398-018-0132-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 12/19/2017] [Accepted: 02/18/2018] [Indexed: 02/05/2023] Open
Abstract
Given its high penetrance, clearly delineated and evolutionary conserved genomic structure, mouse models of the 22q11.2 deletion provide an ideal organism-based and cell-based model of this well-established disease mutation for schizophrenia. In this study we examined the development of changes in intrinsic properties, action potential firing and synaptic transmission using whole-cell patch-clamp recordings of cultured embryonic cortical neurons from Df(16)A +/- and WT mice at DIV7 and DIV14, respectively. Compared to neurons from the WT littermates, significantly increased input resistance and decreased rising rate of action potential was observed in Df(16)A +/- mice at DIV7 but not at DIV14 indicative of delayed neuronal maturation. Neurons from Df(16)A +/- mice also showed significantly higher cellular excitability at both DIV7 and DIV14. Evaluation of Ca2+ homeostasis perturbation caused by 22q11.2 deletion using calcium imaging revealed a significantly lower amplitude of calcium elevation and a smaller area under the curve after depolarization in neurons from Df(16)A +/- mice at both DIV7 and DIV14. Furthermore, the properties of inhibitory synaptic events were significantly altered in Df(16)A +/- mice. We identified changes in mRNA expression profiles, especially in ion channels, receptors, and transporters that may underlie the neurophysiological effects of this mutation. Overall, we show a number of alterations in electrophysiological and calcium homeostatic properties of embryonic cortical neurons from a 22q11.2 deletion mouse model at different culture times and provide valuable insights towards revealing disease mechanisms and discovery of new therapeutic compounds.
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Affiliation(s)
- Ziyi Sun
- Department of Integrated Traditional Chinese and Western Medicine, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, Sichuan, 610041, China. .,Department of Physiology and Cellular Biophysics, College of Physicians and Surgeons, Columbia University, New York, NY, 10032, USA.
| | - Damian J. Williams
- 0000 0001 2285 2675grid.239585.0Columbia Stem Cell Core Facility, Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY 10032 USA
| | - Bin Xu
- 0000 0001 2285 2675grid.239585.0Department of Psychiatry, Columbia University Medical Center, New York, NY 10032 USA
| | - Joseph A. Gogos
- 0000000419368729grid.21729.3fDepartment of Physiology and Cellular Biophysics, College of Physicians and Surgeons, Columbia University, New York, NY 10032 USA ,0000 0001 2285 2675grid.239585.0Department of Neuroscience, Columbia University Medical Center, New York, NY 10032 USA
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10
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Neuronal SphK1 acetylates COX2 and contributes to pathogenesis in a model of Alzheimer's Disease. Nat Commun 2018; 9:1479. [PMID: 29662056 PMCID: PMC5902554 DOI: 10.1038/s41467-018-03674-2] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 03/02/2018] [Indexed: 12/20/2022] Open
Abstract
Although many reports have revealed the importance of defective microglia-mediated amyloid β phagocytosis in Alzheimer’s disease (AD), the underlying mechanism remains to be explored. Here we demonstrate that neurons in the brains of patients with AD and AD mice show reduction of sphingosine kinase1 (SphK1), leading to defective microglial phagocytosis and dysfunction of inflammation resolution due to decreased secretion of specialized proresolving mediators (SPMs). Elevation of SphK1 increased SPMs secretion, especially 15-R-Lipoxin A4, by promoting acetylation of serine residue 565 (S565) of cyclooxygenase2 (COX2) using acetyl-CoA, resulting in improvement of AD-like pathology in APP/PS1 mice. In contrast, conditional SphK1 deficiency in neurons reduced SPMs secretion and abnormal phagocytosis similar to AD. Together, these results uncover a novel mechanism of SphK1 pathogenesis in AD, in which impaired SPMs secretion leads to defective microglial phagocytosis, and suggests that SphK1 in neurons has acetyl-CoA-dependent cytoplasmic acetyltransferase activity towards COX2. Sphingosine kinase (SphK) converts sphingosine into lipids, and is implicated in inflammation. Here the authors show that SphK1 functions as an acetyltransferase, regulates microglial phagocytosis and is reduced in a model of Alzheimer’s Disease, such that its restoration ameliorates pathology
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11
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Kirwan P, Jura M, Merkle FT. Generation and Characterization of Functional Human Hypothalamic Neurons. ACTA ACUST UNITED AC 2017; 81:3.33.1-3.33.24. [PMID: 29064566 DOI: 10.1002/cpns.40] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Neurons in the hypothalamus orchestrate homeostatic physiological processes and behaviors essential for life. Defects in the function of hypothalamic neurons cause a spectrum of human diseases, including obesity, infertility, growth defects, sleep disorders, social disorders, and stress disorders. These diseases have been studied in animal models such as mice, but the rarity and relative inaccessibility of mouse hypothalamic neurons and species-specific differences between mice and humans highlight the need for human cellular models of hypothalamic diseases. We and others have developed methods to differentiate human pluripotent stem cells (hPSCs) into hypothalamic neurons and related cell types, such as astrocytes. This protocol builds on published studies by providing detailed step-by-step instructions for neuronal differentiation, quality control, long-term neuronal maintenance, and the functional interrogation of hypothalamic cells by calcium imaging. Together, these protocols should enable any group with appropriate facilities to generate and study human hypothalamic cells. © 2017 by John Wiley & Sons, Inc.
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Affiliation(s)
- Peter Kirwan
- Metabolic Research Laboratories and Medical Research Council Metabolic Diseases Unit, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom.,The Anne McLaren Laboratory, Wellcome Trust-Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom
| | - Magdalena Jura
- Metabolic Research Laboratories and Medical Research Council Metabolic Diseases Unit, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom.,The Anne McLaren Laboratory, Wellcome Trust-Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom
| | - Florian T Merkle
- Metabolic Research Laboratories and Medical Research Council Metabolic Diseases Unit, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom.,The Anne McLaren Laboratory, Wellcome Trust-Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom
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12
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Parkin Deficiency Reduces Hippocampal Glutamatergic Neurotransmission by Impairing AMPA Receptor Endocytosis. J Neurosci 2017; 36:12243-12258. [PMID: 27903732 DOI: 10.1523/jneurosci.1473-16.2016] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 09/19/2016] [Accepted: 10/18/2016] [Indexed: 12/20/2022] Open
Abstract
Mutations in the gene encoding Parkin, an E3 ubiquitin ligase, lead to juvenile-onset Parkinson's disease by inducing the selective death of midbrain dopaminergic neurons. Accumulating evidence indicates that Parkin also has an important role in excitatory glutamatergic neurotransmission, although its precise mechanism of action remains unclear. Here, we investigate Parkin's role at glutamatergic synapses of rat hippocampal neurons. We find that Parkin-deficient neurons exhibit significantly reduced AMPA receptor (AMPAR)-mediated currents and cell-surface expression, and that these phenotypes result from decreased postsynaptic expression of the adaptor protein Homer1, which is necessary for coupling AMPAR endocytic zones with the postsynaptic density. Accordingly, Parkin loss of function leads to the reduced density of postsynaptic endocytic zones and to impaired AMPAR internalization. These findings demonstrate a novel and essential role for Parkin in glutamatergic neurotransmission, as a stabilizer of postsynaptic Homer1 and the Homer1-linked endocytic machinery necessary for maintaining normal cell-surface AMPAR levels. SIGNIFICANCE STATEMENT Mutations in Parkin, a ubiquitinating enzyme, lead to the selective loss of midbrain dopaminergic neurons and juvenile-onset Parkinson's disease (PD). Parkin loss of function has also been shown to alter hippocampal glutamatergic neurotransmission, providing a potential explanation for PD-associated cognitive impairment. However, very little is known about Parkin's specific sites or mechanisms of action at glutamatergic synapses. Here, we show that Parkin deficiency leads to decreased AMPA receptor-mediated activity due to disruption of the postsynaptic endocytic zones required for maintaining proper cell-surface AMPA receptor levels. These findings demonstrate a novel role for Parkin in synaptic AMPA receptor internalization and suggest a Parkin-dependent mechanism for hippocampal dysfunction that may explain cognitive deficits associated with some forms of PD.
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Zgórzyńska E, Dziedzic B, Gorzkiewicz A, Stulczewski D, Bielawska K, Su KP, Walczewska A. Omega-3 polyunsaturated fatty acids improve the antioxidative defense in rat astrocytes via an Nrf2-dependent mechanism. Pharmacol Rep 2017; 69:935-942. [PMID: 28662394 DOI: 10.1016/j.pharep.2017.04.009] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 02/27/2017] [Accepted: 04/18/2017] [Indexed: 12/11/2022]
Abstract
BACKGROUND Neuronal tolerance to hypoxia and nutrient defficiency highly depends on GSH levels and antioxidant enzyme activity in astrocytes. Omega-3 polyunsaturated fatty acids (ω-3PUFA) enhance antioxidant defence in different cells. The aim of present study was to investigate if ω-3PUFA improve antioxidant status in astrocytes. METHODS Rat primary astrocytes were incubated for 24h with DHA and EPA (30μM), then lysed, fractioned and fatty acids were determined by gas chromatography. GSH and protein thiols were assayed by enzymatic methods. Glutamate cysteine ligase (GCL), glutathione synthetase (GS), glutathione peroxidase 4 (GPx4) and Nrf2 protein expression was validated by Western blot. Intracellular ROS level using H2DCF-DA, and Nrf2 activation by ELISA were measured. RESULTS Incubation of cells with DHA doubled DHA, not EPA content in the membranes, and incubation with EPA increased both fatty acids content compared to control. However, both ω-3PUFAs reduced ROS generation in dose-dependent manner in basal condition and in H2O2-treated cells, and significantly increased GSH, GCL and GPx4 levels. The thiols level was higher only in DHA-treated cells. DHA and EPA activated Nrf2 in a dose-dependent manner but p38MAPK-Nrf2 activation was found only in DHA-enriched astrocytes. CONCLUSION Both ω-3PUFA improved the antioxidant defense in astrocytes via an Nrf2-dependent mechanism, however, upstream pathways of Nrf2 activation may depend on proportion of DHA to EPA incorporated into membrane phospholipids. These results suggest that enrichment of astrocytes with ω-3PUFA may better protect neurons during harmful conditions.
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Affiliation(s)
- Emilia Zgórzyńska
- Department of Cell-to-Cell Communication, Medical University of Lodz, Łódź, Poland.
| | - Barbara Dziedzic
- Department of Cell-to-Cell Communication, Medical University of Lodz, Łódź, Poland
| | - Anna Gorzkiewicz
- Department of Cell-to-Cell Communication, Medical University of Lodz, Łódź, Poland
| | - Dawid Stulczewski
- Department of Cell-to-Cell Communication, Medical University of Lodz, Łódź, Poland
| | - Katarzyna Bielawska
- Department of Analytical Chemistry, Medical University of Bialystok, Białystok, Poland
| | - Kuan-Pin Su
- Department of Psychiatry and Mind-Body Interface Laboratory, China Medical University, Taichung, Taiwan
| | - Anna Walczewska
- Department of Cell-to-Cell Communication, Medical University of Lodz, Łódź, Poland
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14
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Wang L, Egli D, Leibel RL. Efficient Generation of Hypothalamic Neurons from Human Pluripotent Stem Cells. ACTA ACUST UNITED AC 2016; 90:21.5.1-21.5.14. [PMID: 27367166 DOI: 10.1002/cphg.3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The hypothalamus comprises neuronal clusters that are essential for body weight regulation and other physiological functions. Insights into the complex cellular physiology of this region of the brain are critical to understanding the pathogenesis of obesity, but human hypothalamic cells are largely inaccessible for direct study. Here we describe a technique for generation of arcuate-like hypothalamic neurons from human pluripotent stem (hPS) cells. Early activation of SHH signaling and inhibition of BMP and TGFβ signaling, followed by timed inhibition of NOTCH, can efficiently differentiate hPS cells into NKX2.1+ hypothalamic progenitors. Subsequent incubation with BDNF induces the differentiation and maturation of pro-opiomelanocortin and neuropeptide Y neurons, which are major cell types in the arcuate hypothalamus. These neurons have molecular and cellular characteristics consistent with arcuate neurons. © 2016 by John Wiley & Sons, Inc.
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Affiliation(s)
- Liheng Wang
- Naomi Berrie Diabetes Center, Columbia University College of Physicians and Surgeons, New York, New York.,Division of Molecular Genetics, Department of Pediatrics, Columbia University College of Physicians and Surgeons, New York, New York
| | - Dieter Egli
- Naomi Berrie Diabetes Center, Columbia University College of Physicians and Surgeons, New York, New York.,Division of Molecular Genetics, Department of Pediatrics, Columbia University College of Physicians and Surgeons, New York, New York.,New York Stem Cell Foundation Research Institute, New York, New York
| | - Rudolph L Leibel
- Naomi Berrie Diabetes Center, Columbia University College of Physicians and Surgeons, New York, New York.,Division of Molecular Genetics, Department of Pediatrics, Columbia University College of Physicians and Surgeons, New York, New York
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15
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Newland B, Leupelt D, Zheng Y, Thomas LSV, Werner C, Steinhart M, Wang W. Magnetically Controllable Polymer Nanotubes from a Cyclized Crosslinker for Site-Specific Delivery of Doxorubicin. Sci Rep 2015; 5:17478. [PMID: 26619814 PMCID: PMC4664922 DOI: 10.1038/srep17478] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 10/29/2015] [Indexed: 12/17/2022] Open
Abstract
Externally controlled site specific drug delivery could potentially provide a means of reducing drug related side effects whilst maintaining, or perhaps increasing therapeutic efficiency. The aim of this work was to develop a nanoscale drug carrier, which could be loaded with an anti-cancer drug and be directed by an external magnetic field. Using a single, commercially available monomer and a simple one-pot reaction process, a polymer was synthesized and crosslinked within the pores of an anodized aluminum oxide template. These polymer nanotubes (PNT) could be functionalized with iron oxide nanoparticles for magnetic manipulation, without affecting the large internal pore, or inherent low toxicity. Using an external magnetic field the nanotubes could be regionally concentrated, leaving areas devoid of nanotubes. Lastly, doxorubicin could be loaded to the PNTs, causing increased toxicity towards neuroblastoma cells, rendering a platform technology now ready for adaptation with different nanoparticles, degradable pre-polymers, and various therapeutics.
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Affiliation(s)
- Ben Newland
- Leibniz Institute of Polymer Research Dresden, Max Bergmann Centre for Biomaterials Dresden, Hohe Straße. 6, Dresden 01069, Germany
- Brain Repair Group, Schools of Biosciences, Cardiff University, Cardiff, UK
| | - Daniel Leupelt
- Institut für Chemie neuer Materialien, Universität Osnabrück, Barbarastr. 7 D-49069, Osnabrück, Germany
| | - Yu Zheng
- Melville Laboratory for Polymer Synthesis, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Laurent S. V. Thomas
- Leibniz Institute of Polymer Research Dresden, Max Bergmann Centre for Biomaterials Dresden, Hohe Straße. 6, Dresden 01069, Germany
| | - Carsten Werner
- Leibniz Institute of Polymer Research Dresden, Max Bergmann Centre for Biomaterials Dresden, Hohe Straße. 6, Dresden 01069, Germany
| | - Martin Steinhart
- Institut für Chemie neuer Materialien, Universität Osnabrück, Barbarastr. 7 D-49069, Osnabrück, Germany
| | - Wenxin Wang
- The Charles Institute of Dermatology, School of Medicine and Medical Science, University College of Dublin, Dublin, Ireland
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16
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Nwaobi SE, Olsen ML. Correlating Gene-specific DNA Methylation Changes with Expression and Transcriptional Activity of Astrocytic KCNJ10 (Kir4.1). J Vis Exp 2015. [PMID: 26436772 DOI: 10.3791/52406] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
DNA methylation serves to regulate gene expression through the covalent attachment of a methyl group onto the C5 position of a cytosine in a cytosine-guanine dinucleotide. While DNA methylation provides long-lasting and stable changes in gene expression, patterns and levels of DNA methylation are also subject to change based on a variety of signals and stimuli. As such, DNA methylation functions as a powerful and dynamic regulator of gene expression. The study of neuroepigenetics has revealed a variety of physiological and pathological states that are associated with both global and gene-specific changes in DNA methylation. Specifically, striking correlations between changes in gene expression and DNA methylation exist in neuropsychiatric and neurodegenerative disorders, during synaptic plasticity, and following CNS injury. However, as the field of neuroepigenetics continues to expand its understanding of the role of DNA methylation in CNS physiology, delineating causal relationships in regards to changes in gene expression and DNA methylation are essential. Moreover, in regards to the larger field of neuroscience, the presence of vast region and cell-specific differences requires techniques that address these variances when studying the transcriptome, proteome, and epigenome. Here we describe FACS sorting of cortical astrocytes that allows for subsequent examination of a both RNA transcription and DNA methylation. Furthermore, we detail a technique to examine DNA methylation, methylation sensitive high resolution melt analysis (MS-HRMA) as well as a luciferase promoter assay. Through the use of these combined techniques one is able to not only explore correlative changes between DNA methylation and gene expression, but also directly assess if changes in the DNA methylation status of a given gene region are sufficient to affect transcriptional activity.
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Affiliation(s)
- Sinifunanya E Nwaobi
- Department of Cell Developmental and Integrative Biology, University of Alabama at Birmingham
| | - Michelle L Olsen
- Department of Cell Developmental and Integrative Biology, University of Alabama at Birmingham;
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17
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Dixon AR, Philbert MA. Morphometric assessment of toxicant induced neuronal degeneration in full and restricted contact co-cultures of embryonic cortical rat neurons and astrocytes: using m-Dinitrobezene as a model neurotoxicant. Toxicol In Vitro 2015; 29:564-74. [PMID: 25553915 PMCID: PMC4418429 DOI: 10.1016/j.tiv.2014.12.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Revised: 11/05/2014] [Accepted: 12/11/2014] [Indexed: 01/22/2023]
Abstract
With m-Dinitrobenzene (m-DNB) as a selected model neurotoxicant, we demonstrate how to assess neurotoxicity, using morphology based measurement of neurite degeneration, in a conventional "full-contact" and a modern "restricted-contact" co-culture of rat cortical neurons and astrocytes. In the "full-contact" co-culture, neurons and astrocytes in complete physical contact are "globally" exposed to m-DNB. A newly emergent "restricted-contact" co-culture is attained with a microfluidic device that polarizes neuron somas and neurites into separate compartments, and the neurite compartment is "selectively" exposed to m-DNB. Morphometric analysis of the neuronal area revealed that m-DNB exposure produced no significant change in mean neuronal cell area in "full-contact" co-cultures, whereas a significant decrease was observed for neuron monocultures. Neurite elaboration into a neurite exclusive compartment in a compartmentalized microfluidic device, for both monocultures (no astrocytes) and "restricted" co-cultures (astrocytes touching neurites), decreased with exposure to increasing concentrations of m-DNB, but the average neurite area was higher in co-cultures. By using co-culture systems that more closely approach biological and architectural complexities, and the directionality of exposure found in the brain, this study provides a methodological foundation for unraveling the role of physical contact between astrocytes and neurons in mitigating the toxic effects of chemicals such as m-DNB.
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Affiliation(s)
- Angela R Dixon
- Toxicology Program, School of Public Health, University of Michigan, Ann Arbor, MI 48109, United States.
| | - Martin A Philbert
- Toxicology Program, School of Public Health, University of Michigan, Ann Arbor, MI 48109, United States.
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18
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Avants BW, Murphy DB, Dapello JA, Robinson JT. NeuroPG: open source software for optical pattern generation and data acquisition. FRONTIERS IN NEUROENGINEERING 2015; 8:1. [PMID: 25784873 PMCID: PMC4345891 DOI: 10.3389/fneng.2015.00001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 02/09/2015] [Indexed: 11/29/2022]
Abstract
Patterned illumination using a digital micromirror device (DMD) is a powerful tool for optogenetics. Compared to a scanning laser, DMDs are inexpensive and can easily create complex illumination patterns. Combining these complex spatiotemporal illumination patterns with optogenetics allows DMD-equipped microscopes to probe neural circuits by selectively manipulating the activity of many individual cells or many subcellular regions at the same time. To use DMDs to study neural activity, scientists must develop specialized software to coordinate optical stimulation patterns with the acquisition of electrophysiological and fluorescence data. To meet this growing need we have developed an open source optical pattern generation software for neuroscience—NeuroPG—that combines, DMD control, sample visualization, and data acquisition in one application. Built on a MATLAB platform, NeuroPG can also process, analyze, and visualize data. The software is designed specifically for the Mightex Polygon400; however, as an open source package, NeuroPG can be modified to incorporate any data acquisition, imaging, or illumination equipment that is compatible with MATLAB’s Data Acquisition and Image Acquisition toolboxes.
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Affiliation(s)
- Benjamin W Avants
- Department of Electrical and Computer Engineering, Rice University Houston, TX, USA
| | - Daniel B Murphy
- Department of Electrical and Computer Engineering, Rice University Houston, TX, USA
| | | | - Jacob T Robinson
- Department of Electrical and Computer Engineering, Rice University Houston, TX, USA ; Department of Bioengineering, Rice University Houston, TX, USA ; Department of Neuroscience, Baylor College of Medicine Houston, TX, USA
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19
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Synergistic binding of transcription factors to cell-specific enhancers programs motor neuron identity. Nat Neurosci 2013; 16:1219-27. [PMID: 23872598 DOI: 10.1038/nn.3467] [Citation(s) in RCA: 155] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2013] [Accepted: 06/18/2013] [Indexed: 12/14/2022]
Abstract
Efficient transcriptional programming promises to open new frontiers in regenerative medicine. However, mechanisms by which programming factors transform cell fate are unknown, preventing more rational selection of factors to generate desirable cell types. Three transcription factors, Ngn2, Isl1 and Lhx3, were sufficient to program rapidly and efficiently spinal motor neuron identity when expressed in differentiating mouse embryonic stem cells. Replacement of Lhx3 by Phox2a led to specification of cranial, rather than spinal, motor neurons. Chromatin immunoprecipitation-sequencing analysis of Isl1, Lhx3 and Phox2a binding sites revealed that the two cell fates were programmed by the recruitment of Isl1-Lhx3 and Isl1-Phox2a complexes to distinct genomic locations characterized by a unique grammar of homeodomain binding motifs. Our findings suggest that synergistic interactions among transcription factors determine the specificity of their recruitment to cell type-specific binding sites and illustrate how a single transcription factor can be repurposed to program different cell types.
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20
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Abstract
Glial reaction is a common feature of neurodegenerative diseases. Recent studies have suggested that reactive astrocytes gain neurotoxic properties, but exactly how reactive astrocytes contribute to neurotoxicity remains to be determined. Here, we identify lipocalin 2 (lcn2) as an inducible factor that is secreted by reactive astrocytes and that is selectively toxic to neurons. We show that lcn2 is induced in reactive astrocytes in transgenic rats with neuronal expression of mutant human TAR DNA-binding protein 43 (TDP-43) or RNA-binding protein fused in sarcoma (FUS). Therefore, lcn2 is induced in activated astrocytes in response to neurodegeneration, but its induction is independent of TDP-43 or FUS expression in astrocytes. We found that synthetic lcn2 is cytotoxic to primary neurons in a dose-dependent manner, but is innocuous to astrocytes, microglia, and oligodendrocytes. Lcn2 toxicity is increased in neurons that express a disease gene, such as mutant FUS or TDP-43. Conditioned medium from rat brain slice cultures with neuronal expression of mutant TDP-43 contains abundant lcn2 and is toxic to primary neurons as well as neurons in cultured brain slice from WT rats. Partial depletion of lcn2 by immunoprecipitation reduced conditioned medium-mediated neurotoxicity. Our data indicate that reactive astrocytes secrete lcn2, which is a potent neurotoxic mediator.
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21
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Joseph DJ, Williams DJ, MacDermott AB. Modulation of neurite outgrowth by activation of calcium-permeable kainate receptors expressed by rat nociceptive-like dorsal root ganglion neurons. Dev Neurobiol 2011; 71:818-35. [PMID: 21557511 PMCID: PMC3973019 DOI: 10.1002/dneu.20906] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Neurite outgrowth is a fundamental step in establishing proper neuronal connections in the developing central nervous system. Dynamic control of outgrowth has been attributed to changes in growth cone Ca2+ levels in response to extracellular cues. Here we have investigated a possible role for Ca2+ permeable kainate (KA) receptors in regulating neurite outgrowth of nociceptive-like dorsal root ganglion (DRG) neurons. To identify KA receptor subunits likely to be involved, we used quantitative RT-PCR on acutely dissociated DRG and dorsal horn neurons. DRG neurons expressed more GluK1, particularly the GluK1b spice variant, than dorsal horn neurons. Conversely, dorsal horn neurons expressed more GluK2, particularly GluK2a, than DRG neurons. Further, an RNA editing assay indicated that the majority of GluK1 and GluK2 mRNA transcripts in DRG were unedited. Imaging Ca2+ transients following application of a KA receptor agonist to DRG and dorsal horn co-cultures revealed increases in intracellular Ca2+ in the growth cones of DRG neurons. In the majority of cases, this increase in Ca2+ was partly or completely blocked by Joro spider toxin (JSTX), an antagonist for Ca2+-permeable AMPA and KA receptors. Treatment of DRG/dorsal horn co-cultures with KA for 18 hours suppressed neurite outgrowth while application of the rapidly desensitizing KA receptor agonist SYM 2081, the competitive AMPA/KA receptor antagonist, CNQX, and JSTX or philanthotoxin enhanced neurite outgrowth and prevented KA effects on neurite outgrowth. Thus, Ca2+ entry through KA receptors at the growth cone of DRG neurons may be an important regulator of neurite outgrowth.
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Affiliation(s)
- Donald J. Joseph
- Program in Neurobiology and Behavior-Department of Neuroscience, Columbia University, New York, NY 10032
| | - Damian J. Williams
- Department of Physiology and Biophysics, Columbia University, New York, NY 10032
| | - Amy B. MacDermott
- Program in Neurobiology and Behavior-Department of Neuroscience, Columbia University, New York, NY 10032
- Department of Physiology and Biophysics, Columbia University, New York, NY 10032
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22
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Joseph DJ, Choudhury P, MacDermott AB. An in vitro assay system for studying synapse formation between nociceptive dorsal root ganglion and dorsal horn neurons. J Neurosci Methods 2010; 189:197-204. [PMID: 20385165 PMCID: PMC2880384 DOI: 10.1016/j.jneumeth.2010.04.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2010] [Revised: 03/25/2010] [Accepted: 04/05/2010] [Indexed: 01/23/2023]
Abstract
Synapses between nociceptive dorsal root ganglion (DRG) neurons and spinal cord dorsal horn neurons represent the first loci for transmission of painful stimuli. Our knowledge of the molecular organization and development of these synapses is sparse due, partly, to a lack of a reliable model system that reconstitutes synaptogenesis between these two neuronal populations. To address this issue, we have established an in vitro assay system consisting of separately purified DRG neurons and dorsal horn neurons on astrocyte microislands. Using immunocytochemistry, we have found that 97%, 93%, 98%, 96%, and 94% of DRG neurons on these microislands express markers often associated with nociceptive neurons including Substance P, TRPV1, calcitonin-gene related peptide (CGRP), TrKA, and peripherin, respectively. Triple labeling with these nociceptive-like markers, synaptic vesicle marker Vglut2 and using MAP2 as a dendritic marker revealed the presence of nociceptive-like markers at synaptic terminals. Using this immunocytochemical approach, we counted contact points as overlapping MAP2/Vglut2 puncta and showed that they increased with time in culture. Single and dual patch-clamp recordings showed that overlapping Vglut2/MAP2 puncta observed after a few days in culture are likely to be functional synapses between DRG and dorsal horn neurons in our in vitro assay system. Taken together, these data suggest our co-culture microisland model system consists of mostly nociceptive-like DRG neurons that express presynaptic markers and form functional synapses with their dorsal horn partners. Thus, this model system may have direct application for studies on factors regulating development of nociceptive DRG/dorsal horn synapses.
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Affiliation(s)
- Donald J. Joseph
- Program in Neurobiology and Behavior-Department of Neuroscience, College of Physicians and Surgeons, Columbia University, New York, NY 10032
| | - Papiya Choudhury
- Department of Physiology and Biophysics, College of Physicians and Surgeons, Columbia University, New York, NY 10032
| | - Amy B. MacDermott
- Program in Neurobiology and Behavior-Department of Neuroscience, College of Physicians and Surgeons, Columbia University, New York, NY 10032
- Department of Physiology and Biophysics, College of Physicians and Surgeons, Columbia University, New York, NY 10032
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Albuquerque C, Joseph DJ, Choudhury P, MacDermott AB. Dissection, plating, and maintenance of dorsal horn neuron cultures. Cold Spring Harb Protoc 2010; 2009:pdb.prot5274. [PMID: 20147250 DOI: 10.1101/pdb.prot5274] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Cristóvão Albuquerque
- Department of Physiology and Cellular Biophysics and Department of Neuroscience, Columbia University, New York, NY 10032, USA
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Albuquerque C, Joseph DJ, Choudhury P, MacDermott AB. Preparation of coverslips for neuronal cultures. Cold Spring Harb Protoc 2010; 2009:pdb.prot5272. [PMID: 20147248 DOI: 10.1101/pdb.prot5272] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Cristóvão Albuquerque
- Department of Physiology and Cellular Biophysics and Department of Neuroscience, Columbia University, New York, NY 10032, USA
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25
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Albuquerque C, Joseph DJ, Choudhury P, MacDermott AB. Dissection, plating, and maintenance of dorsal root ganglion neurons for monoculture and for coculture with dorsal horn neurons. Cold Spring Harb Protoc 2010; 2009:pdb.prot5275. [PMID: 20147251 DOI: 10.1101/pdb.prot5275] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- Cristóvão Albuquerque
- Department of Physiology and Cellular Biophysics and Department of Neuroscience, Columbia University, New York, NY 10032, USA
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