1
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Fuhrmann F, Nebeling FC, Musacchio F, Mittag M, Poll S, Müller M, Ambrad Giovannetti E, Maibach M, Schaffran B, Burnside E, Chan ICW, Lagurin AS, Reichenbach N, Kaushalya S, Fried H, Linden S, Petzold GC, Tavosanis G, Bradke F, Fuhrmann M. Three-photon in vivo imaging of neurons and glia in the medial prefrontal cortex with sub-cellular resolution. Commun Biol 2025; 8:795. [PMID: 40410447 PMCID: PMC12102176 DOI: 10.1038/s42003-025-08079-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2024] [Accepted: 04/11/2025] [Indexed: 05/25/2025] Open
Abstract
The medial prefrontal cortex (mPFC) is important for higher cognitive functions, including working memory, decision making, and emotional control. In vivo recordings of neuronal activity in the mPFC have been achieved via invasive electrical and optical approaches. Here we apply low invasive three-photon in vivo imaging in the mPFC of the mouse at unprecedented depth. Specifically, we measure neuronal and astrocytic Ca2+-transient parameters in awake head-fixed mice up to a depth of 1700 µm. Furthermore, we longitudinally record dendritic spine density (0.41 ± 0.07 µm-1) deeper than 1 mm for a week. Using 1650 nm wavelength to excite red fluorescent microglia, we quantify their processes' motility (58.9 ± 2% turnover rate) at previously unreachable depths (1100 µm). We establish three-photon imaging of the mPFC enabling neuronal and glial recordings with subcellular resolution that will pave the way for novel discoveries in this brain region.
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Affiliation(s)
- Falko Fuhrmann
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Felix C Nebeling
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
- Department of Neurooncology, Center for Neurology, University Hospital Bonn, Bonn, Germany
| | - Fabrizio Musacchio
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Manuel Mittag
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Stefanie Poll
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
- IEECR, University Clinic Bonn, Bonn, Germany
| | - Monika Müller
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | | | - Michael Maibach
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Barbara Schaffran
- Axon Growth and Regeneration Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Emily Burnside
- Axon Growth and Regeneration Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Ivy Chi Wai Chan
- Dynamics of Neuronal Circuits Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
- Department of Developmental Biology, RWTH Aachen University, Aachen, Germany
| | - Alex Simon Lagurin
- Dynamics of Neuronal Circuits Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Nicole Reichenbach
- Vascular Neurology Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Sanjeev Kaushalya
- Core Research Facilities and Services, Light Microscope Facility, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Hans Fried
- Core Research Facilities and Services, Light Microscope Facility, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Stefan Linden
- Department of Physics, Nanophotonics, University of Bonn, Bonn, Germany
| | - Gabor C Petzold
- Vascular Neurology Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
- Division of Vascular Neurology, University Hospital Bonn, Bonn, Germany
| | - Gaia Tavosanis
- Dynamics of Neuronal Circuits Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
- LIMES, University of Bonn, Bonn, Germany
- Department of Developmental Biology, RWTH Aachen University, Aachen, Germany
| | - Frank Bradke
- Axon Growth and Regeneration Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Martin Fuhrmann
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.
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2
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Mi X, Chen ABY, Duarte D, Carey E, Taylor CR, Braaker PN, Bright M, Almeida RG, Lim JX, Ruetten VMS, Wang Y, Wang M, Zhang W, Zheng W, Reitman ME, Huang Y, Wang X, Li L, Deng H, Shi SH, Poskanzer KE, Lyons DA, Nimmerjahn A, Ahrens MB, Yu G. Fast, accurate, and versatile data analysis platform for the quantification of molecular spatiotemporal signals. Cell 2025; 188:2794-2809.e21. [PMID: 40203826 DOI: 10.1016/j.cell.2025.03.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2024] [Revised: 01/13/2025] [Accepted: 03/06/2025] [Indexed: 04/11/2025]
Abstract
Optical recording of intricate molecular dynamics is becoming an indispensable technique for biological studies, accelerated by the development of new or improved biosensors and microscopy technology. This creates major computational challenges to extract and quantify biologically meaningful spatiotemporal patterns embedded within complex and rich data sources, many of which cannot be captured with existing methods. Here, we introduce activity quantification and analysis (AQuA2), a fast, accurate, and versatile data analysis platform built upon advanced machine-learning techniques. It decomposes complex live-imaging-based datasets into elementary signaling events, allowing accurate and unbiased quantification of molecular activities and identification of consensus functional units. We demonstrate applications across a wide range of biosensors, cell types, organs, animal models, microscopy techniques, and imaging approaches. As exemplar findings, we show how AQuA2 identified drug-dependent interactions between neurons and astroglia, as well as distinct sensorimotor signal propagation patterns in the mouse spinal cord.
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Affiliation(s)
- Xuelong Mi
- Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Arlington, VA 22203, USA
| | - Alex Bo-Yuan Chen
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA; Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA; Graduate Program in Neuroscience, Harvard Medical School, Boston, MA 02115, USA
| | - Daniela Duarte
- Waitt Advanced Biophotonics Center, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Erin Carey
- Waitt Advanced Biophotonics Center, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Charlotte R Taylor
- Department of Biochemistry & Biophysics, University of California, San Francisco, San Francisco, CA, USA; Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA, USA
| | - Philipp N Braaker
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh BioQuarter, Edinburgh EH16 4SB, UK
| | - Mark Bright
- Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Arlington, VA 22203, USA
| | - Rafael G Almeida
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh BioQuarter, Edinburgh EH16 4SB, UK
| | - Jing-Xuan Lim
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Virginia M S Ruetten
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA; Gatsby Computational Neuroscience Unit, UCL, London W1T 4JG, UK
| | - Yizhi Wang
- Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Arlington, VA 22203, USA
| | - Mengfan Wang
- Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Arlington, VA 22203, USA
| | - Weizhan Zhang
- Department of Automation, Tsinghua University, Beijing 100084, China; IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China
| | - Wei Zheng
- Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Arlington, VA 22203, USA
| | - Michael E Reitman
- Department of Biochemistry & Biophysics, University of California, San Francisco, San Francisco, CA, USA; Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA, USA
| | - Yongkang Huang
- IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China; New Cornerstone Science Laboratory, Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Xiaoyu Wang
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Lei Li
- IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China; New Cornerstone Science Laboratory, Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - HanFei Deng
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Song-Hai Shi
- IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China; New Cornerstone Science Laboratory, Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Kira E Poskanzer
- Department of Biochemistry & Biophysics, University of California, San Francisco, San Francisco, CA, USA; Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA, USA; Kavli Institute for Fundamental Neuroscience, San Francisco, CA, USA
| | - David A Lyons
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh BioQuarter, Edinburgh EH16 4SB, UK
| | - Axel Nimmerjahn
- Waitt Advanced Biophotonics Center, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA.
| | - Misha B Ahrens
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA.
| | - Guoqiang Yu
- Department of Automation, Tsinghua University, Beijing 100084, China; IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China; Beijing National Research Center for Information Science and Technology, Beijing 100084, China.
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3
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Fisher DG, Cruz T, Hoch MR, Sharifi KA, Shah IM, Gorick CM, Breza VR, Debski AC, Samuels JD, Sheehan JP, Schlesinger D, Moore D, Mandell JW, Lukens JR, Miller GW, Tvrdik P, Price RJ. Focused ultrasound-microbubble treatment arrests the growth and formation of cerebral cavernous malformations. Nat Biomed Eng 2025:10.1038/s41551-025-01390-z. [PMID: 40360762 DOI: 10.1038/s41551-025-01390-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Accepted: 04/03/2025] [Indexed: 05/15/2025]
Abstract
Cerebral cavernous malformations (CCMs) are vascular lesions within the central nervous system that cause debilitating neurological symptoms. Currently, surgical excision and stereotactic radiosurgery, the primary treatment options, pose risks to some patients. Here we tested whether pulsed, low intensity, focused ultrasound-microbubble (FUS-MB) treatments control CCM growth and formation in a clinically representative Krit1 null murine model. FUS-MB under magnetic resonance imaging (MRI) guidance opened the blood-brain barrier, with gadolinium contrast agent deposition most evident at perilesional boundaries. Longitudinal MRI revealed that, at 1 month after treatment, FUS-MB halted the growth of 94% of treated CCMs. In contrast, untreated CCMs grew ~7-fold in volume. FUS-MB-treated CCMs exhibited a marked reduction in Krit1 null endothelial cells. In mice receiving multiple FUS-MB treatments with fixed peak-negative pressures, de novo CCM formation was reduced by 81%, indicating a prophylactic effect. Our findings support FUS-MB as a minimally invasive treatment modality that can safely arrest murine CCM growth and prevent de novo CCM formation in mice. If proven safe and effective in clinical trials, FUS-MB treatment may enhance therapeutic options for CCM patients.
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Affiliation(s)
- Delaney G Fisher
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
| | - Tanya Cruz
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
| | - Matthew R Hoch
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
| | - Khadijeh A Sharifi
- Department of Neuroscience, University of Virginia, Charlottesville, VA, USA
- Department of Neurological Surgery, University of Virginia Health System, Charlottesville, VA, USA
| | - Ishaan M Shah
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
| | - Catherine M Gorick
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
| | - Victoria R Breza
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
| | - Anna C Debski
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
| | - Joshua D Samuels
- Department of Neuroscience, University of Virginia, Charlottesville, VA, USA
| | - Jason P Sheehan
- Department of Neurological Surgery, University of Virginia Health System, Charlottesville, VA, USA
| | - David Schlesinger
- Department of Radiation Oncology, University of Virginia Health System, Charlottesville, VA, USA
| | - David Moore
- Focused Ultrasound Foundation, Charlottesville, VA, USA
| | - James W Mandell
- Department of Pathology, University of Virginia, Charlottesville, VA, USA
| | - John R Lukens
- Department of Neuroscience, University of Virginia, Charlottesville, VA, USA
| | - G Wilson Miller
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, USA
| | - Petr Tvrdik
- Department of Neuroscience, University of Virginia, Charlottesville, VA, USA.
- Department of Neurological Surgery, University of Virginia Health System, Charlottesville, VA, USA.
| | - Richard J Price
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA.
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, USA.
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4
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Korte N, Barkaway A, Wells J, Freitas F, Sethi H, Andrews SP, Skidmore J, Stevens B, Attwell D. Inhibiting Ca 2+ channels in Alzheimer's disease model mice relaxes pericytes, improves cerebral blood flow and reduces immune cell stalling and hypoxia. Nat Neurosci 2024; 27:2086-2100. [PMID: 39294491 PMCID: PMC11537984 DOI: 10.1038/s41593-024-01753-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 08/06/2024] [Indexed: 09/20/2024]
Abstract
Early in Alzheimer's disease (AD), pericytes constrict capillaries, increasing their hydraulic resistance and trapping of immune cells and, thus, decreasing cerebral blood flow (CBF). Therapeutic approaches to attenuate pericyte-mediated constriction in AD are lacking. Here, using in vivo two-photon imaging with laser Doppler and speckle flowmetry and magnetic resonance imaging, we show that Ca2+ entry via L-type voltage-gated calcium channels (CaVs) controls the contractile tone of pericytes. In AD model mice, we identifed pericytes throughout the capillary bed as key drivers of an immune reactive oxygen species (ROS)-evoked and pericyte intracellular calcium concentration ([Ca2+]i)-mediated decrease in microvascular flow. Blocking CaVs with nimodipine early in disease progression improved CBF, reduced leukocyte stalling at pericyte somata and attenuated brain hypoxia. Amyloid β (Aβ)-evoked pericyte contraction in human cortical tissue was also greatly reduced by CaV block. Lowering pericyte [Ca2+]i early in AD may, thus, offer a therapeutic strategy to enhance brain energy supply and possibly cognitive function in AD.
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Affiliation(s)
- Nils Korte
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, UK.
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
| | - Anna Barkaway
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, UK
| | - Jack Wells
- UCL Centre for Advanced Biomedical Imaging, Division of Medicine, University College London, London, UK
| | - Felipe Freitas
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, UK
| | - Huma Sethi
- Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, London, UK
| | - Stephen P Andrews
- ALBORADA Drug Discovery Institute, University of Cambridge, Cambridge, UK
| | - John Skidmore
- ALBORADA Drug Discovery Institute, University of Cambridge, Cambridge, UK
| | - Beth Stevens
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
- Stanley Center, Broad Institute, Cambridge, MA, USA
| | - David Attwell
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, UK.
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5
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Hoyt KR, Horning P, Georgette Ang P, Karelina K, Obrietan K. Ribosomal S6 kinase signaling regulates neuronal viability during development and confers resistance to excitotoxic cell death in mature neurons. Neuroscience 2024; 558:1-10. [PMID: 39137868 DOI: 10.1016/j.neuroscience.2024.08.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2024] [Accepted: 08/08/2024] [Indexed: 08/15/2024]
Abstract
The Ribosomal S6 Kinase (RSK) family of serine/threonine kinases function as key downstream effectors of the MAPK signaling cascade. In the nervous system, RSK signaling plays crucial roles in neuronal development and contributes to activity-dependent neuronal plasticity. This study examined the role of RSK signaling in cell viability during neuronal development and in neuroprotection in the mature nervous system. Using neuronal cell-culture-based profiling, we found that suppressing RSK signaling led to significant cell death in developing primary neuronal cultures. To this end, treatment with the RSK inhibitors BiD1870 or SL0101 on the first day of culturing resulted in over 80% cell death. In contrast, more mature cultures showed attenuated cell death upon RSK inhibition. Inhibition of RSK signaling during early neuronal development also disrupted neurite outgrowth and cell growth. In maturing hippocampal explant cultures, treatment with BiD1870 had minimal effects on cell viability, but led to a striking augmentation of NMDA-induced cell death. Finally, we used the endothelin 1 (ET-1) model of ischemia to examine the neuroprotective effects of RSK signaling in the mature hippocampus in vivo. Notably, in the absence of RSK inhibition, the granule cell layer (GCL) was resistant to the effects of ET-1; However, disruption of RSK signaling (via the microinjection of BiD1870) prior to ET-1 injection triggered cell death within the GCL, thus indicating a neuroprotective role for RSK signaling in the mature nervous system. Together these data reveal distinct, developmentally-defined, roles for RSK signaling in the nervous system.
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Affiliation(s)
- Kari R Hoyt
- Division of Pharmaceutics and Pharmacology, Ohio State University, Columbus, OH, USA.
| | - Paul Horning
- Department of Neuroscience, Ohio State University, Columbus, OH, USA; Division of Pharmaceutics and Pharmacology, Ohio State University, Columbus, OH, USA
| | - Pia Georgette Ang
- Division of Pharmaceutics and Pharmacology, Ohio State University, Columbus, OH, USA
| | - Kate Karelina
- Department of Neuroscience, Ohio State University, Columbus, OH, USA
| | - Karl Obrietan
- Department of Neuroscience, Ohio State University, Columbus, OH, USA.
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6
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Yue WWS, Touhara KK, Toma K, Duan X, Julius D. Endogenous opioid signalling regulates spinal ependymal cell proliferation. Nature 2024; 634:407-414. [PMID: 39294372 DOI: 10.1038/s41586-024-07889-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 07/31/2024] [Indexed: 09/20/2024]
Abstract
After injury, mammalian spinal cords develop scars to confine the lesion and prevent further damage. However, excessive scarring can hinder neural regeneration and functional recovery1,2. These competing actions underscore the importance of developing therapeutic strategies to dynamically modulate scar progression. Previous research on scarring has primarily focused on astrocytes, but recent evidence has suggested that ependymal cells also participate. Ependymal cells normally form the epithelial layer encasing the central canal, but they undergo massive proliferation and differentiation into astroglia following certain injuries, becoming a core scar component3-7. However, the mechanisms regulating ependymal proliferation in vivo remain unclear. Here we uncover an endogenous κ-opioid signalling pathway that controls ependymal proliferation. Specifically, we detect expression of the κ-opioid receptor, OPRK1, in a functionally under-characterized cell type known as cerebrospinal fluid-contacting neuron (CSF-cN). We also discover a neighbouring cell population that expresses the cognate ligand prodynorphin (PDYN). Whereas κ-opioids are typically considered inhibitory, they excite CSF-cNs to inhibit ependymal proliferation. Systemic administration of a κ-antagonist enhances ependymal proliferation in uninjured spinal cords in a CSF-cN-dependent manner. Moreover, a κ-agonist impairs ependymal proliferation, scar formation and motor function following injury. Together, our data suggest a paracrine signalling pathway in which PDYN+ cells tonically release κ-opioids to stimulate CSF-cNs and suppress ependymal proliferation, revealing an endogenous mechanism and potential pharmacological strategy for modulating scarring after spinal cord injury.
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Affiliation(s)
- Wendy W S Yue
- Department of Physiology, University of California, San Francisco, CA, USA.
| | - Kouki K Touhara
- Department of Physiology, University of California, San Francisco, CA, USA
| | - Kenichi Toma
- Department of Ophthalmology, University of California, San Francisco, CA, USA
| | - Xin Duan
- Department of Ophthalmology, University of California, San Francisco, CA, USA
| | - David Julius
- Department of Physiology, University of California, San Francisco, CA, USA.
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7
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Gyarmati G, Shroff UN, Izuhara A, Deepak S, Komers R, Bedard PW, Peti-Peterdi J. Sparsentan improves glomerular hemodynamics, cell functions, and tissue repair in a mouse model of FSGS. JCI Insight 2024; 9:e177775. [PMID: 39226116 PMCID: PMC11466195 DOI: 10.1172/jci.insight.177775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 08/28/2024] [Indexed: 09/05/2024] Open
Abstract
Dual endothelin-1 (ET-1) and angiotensin II (AngII) receptor antagonism with sparsentan has strong antiproteinuric actions via multiple potential mechanisms that are more pronounced, or additive, compared with current standard of care using angiotensin receptor blockers (ARBs). Considering the many actions of ET-1 and AngII on multiple cell types, this study aimed to determine glomeruloprotective mechanisms of sparsentan compared to the ARB losartan by direct visualization of its effects in the intact kidney in focal segmental glomerulosclerosis (FSGS) using intravital multiphoton microscopy. In both healthy and FSGS models, sparsentan treatment increased afferent/efferent arteriole diameters; increased or preserved blood flow and single-nephron glomerular filtration rate; attenuated acute ET-1 and AngII-induced increases in podocyte calcium; reduced proteinuria; preserved podocyte number; increased both endothelial and renin lineage cells and clones in vasculature, glomeruli, and tubules; restored glomerular endothelial glycocalyx; and attenuated mitochondrial stress and immune cell homing. These effects were either not observed or of smaller magnitude with losartan. The pleiotropic nephroprotective effects of sparsentan included improved hemodynamics, podocyte and endothelial cell functions, and tissue repair. Compared with losartan, sparsentan was more effective in the sustained preservation of kidney structure and function, which underscores the importance of the ET-1 component in FSGS pathogenesis and therapy.
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Affiliation(s)
- Georgina Gyarmati
- Departments of Physiology and Neuroscience, and Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, California, USA
| | - Urvi Nikhil Shroff
- Departments of Physiology and Neuroscience, and Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, California, USA
| | - Audrey Izuhara
- Departments of Physiology and Neuroscience, and Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, California, USA
| | - Sachin Deepak
- Departments of Physiology and Neuroscience, and Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, California, USA
| | - Radko Komers
- Travere Therapeutics, San Diego, California, USA
| | | | - Janos Peti-Peterdi
- Departments of Physiology and Neuroscience, and Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, California, USA
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8
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Masala N, Mittag M, Giovannetti EA, O'Neil DA, Distler FJ, Rupprecht P, Helmchen F, Yuste R, Fuhrmann M, Beck H, Wenzel M, Kelly T. Aberrant hippocampal Ca 2+ microwaves following synapsin-dependent adeno-associated viral expression of Ca 2+ indicators. eLife 2024; 13:RP93804. [PMID: 39042440 PMCID: PMC11265795 DOI: 10.7554/elife.93804] [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: 07/24/2024] Open
Abstract
Genetically encoded calcium indicators (GECIs) such as GCaMP are invaluable tools in neuroscience to monitor neuronal activity using optical imaging. The viral transduction of GECIs is commonly used to target expression to specific brain regions, can be conveniently used with any mouse strain of interest without the need for prior crossing with a GECI mouse line, and avoids potential hazards due to the chronic expression of GECIs during development. A key requirement for monitoring neuronal activity with an indicator is that the indicator itself minimally affects activity. Here, using common adeno-associated viral (AAV) transduction procedures, we describe spatially confined aberrant Ca2+ microwaves slowly travelling through the hippocampus following expression of GCaMP6, GCaMP7, or R-CaMP1.07 driven by the synapsin promoter with AAV-dependent gene transfer in a titre-dependent fashion. Ca2+ microwaves developed in hippocampal CA1 and CA3, but not dentate gyrus nor neocortex, were typically first observed at 4 wk after viral transduction, and persisted up to at least 8 wk. The phenomenon was robust and observed across laboratories with various experimenters and setups. Our results indicate that aberrant hippocampal Ca2+ microwaves depend on the promoter and viral titre of the GECI, density of expression, as well as the targeted brain region. We used an alternative viral transduction method of GCaMP which avoids this artefact. The results show that commonly used Ca2+-indicator AAV transduction procedures can produce artefactual Ca2+ responses. Our aim is to raise awareness in the field of these artefactual transduction-induced Ca2+ microwaves, and we provide a potential solution.
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Affiliation(s)
- Nicola Masala
- University of Bonn, Faculty of Medicine, Institute for Experimental Epileptology and Cognition Research (IEECR)BonnGermany
- University Hospital BonnBonnGermany
- Department of Epileptology, University Hospital BonnBonnGermany
| | - Manuel Mittag
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases (DZNE)BonnGermany
| | | | - Darik A O'Neil
- NeuroTechnology Center, Columbia UniversityNew YorkUnited States
| | - Fabian J Distler
- University of Bonn, Faculty of Medicine, Institute for Experimental Epileptology and Cognition Research (IEECR)BonnGermany
- University Hospital BonnBonnGermany
| | - Peter Rupprecht
- Brain Research Institute, University of ZurichZurichSwitzerland
- Neuroscience Center Zurich, University of ZurichZurichSwitzerland
| | - Fritjof Helmchen
- Brain Research Institute, University of ZurichZurichSwitzerland
- Neuroscience Center Zurich, University of ZurichZurichSwitzerland
| | - Rafael Yuste
- NeuroTechnology Center, Columbia UniversityNew YorkUnited States
| | - Martin Fuhrmann
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases (DZNE)BonnGermany
| | - Heinz Beck
- University of Bonn, Faculty of Medicine, Institute for Experimental Epileptology and Cognition Research (IEECR)BonnGermany
- University Hospital BonnBonnGermany
- German Center for Neurodegenerative Diseases (DZNE)BonnGermany
| | - Michael Wenzel
- University of Bonn, Faculty of Medicine, Institute for Experimental Epileptology and Cognition Research (IEECR)BonnGermany
- University Hospital BonnBonnGermany
- Department of Epileptology, University Hospital BonnBonnGermany
| | - Tony Kelly
- University of Bonn, Faculty of Medicine, Institute for Experimental Epileptology and Cognition Research (IEECR)BonnGermany
- University Hospital BonnBonnGermany
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9
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Kleinboehl EW, Laoharawee K, Lahr WS, Jensen JD, Peterson JJ, Bell JB, Webber BR, Moriarity BS. Development and testing of a versatile genome editing application reporter (V-GEAR) system. Mol Ther Methods Clin Dev 2024; 32:101253. [PMID: 38764780 PMCID: PMC11101715 DOI: 10.1016/j.omtm.2024.101253] [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: 01/04/2024] [Accepted: 04/18/2024] [Indexed: 05/21/2024]
Abstract
CRISPR-Cas9 and novel cas fusion proteins leveraging specific DNA targeting ability combined with deaminases or reverse transcriptases have revolutionized genome editing. However, their efficacy heavily relies upon protein variants, targeting single guide RNAs, and surrounding DNA sequence context within the targeted loci. This necessitates the need for efficient and rapid screening methods to evaluate these editing reagents and designs. Existing plasmid-based reporters lack flexibility, being fixed to specific DNA sequences, hindering direct comparisons between various editing approaches. To address this, we developed the versatile genome editing application reporter (V-GEAR) system. V-GEAR comprises genes detectable after desired editing via base editing, prime editing, or homology-directed repair within relevant genomic contexts. It employs a detectable synthetic cell surface protein (RQR8) followed by a customizable target sequence resembling genomic regions of interest. These genes allow for reliable identification of corrective editing and cell enrichment. We validated the V-GEAR system with base editors, prime editors, and Cas9-mediated homology-directed repair. Furthermore, the V-GEAR system offers versatility by allowing transient screening or stable integration at the AAVS1 safe harbor loci, rapidly achieved through immunomagnetic isolation. This innovative system enables direct comparisons among editing technologies, accelerating the development and testing of genome editing approaches.
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Affiliation(s)
- Evan W. Kleinboehl
- Department of Pediatrics, University of Minnesota, Minneapolis, MN 55455, USA
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA
- Center for Genome Engineering, University of Minnesota, Minneapolis, MN 55455, USA
| | - Kanut Laoharawee
- Department of Pediatrics, University of Minnesota, Minneapolis, MN 55455, USA
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA
- Center for Genome Engineering, University of Minnesota, Minneapolis, MN 55455, USA
| | - Walker S. Lahr
- Department of Pediatrics, University of Minnesota, Minneapolis, MN 55455, USA
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA
- Center for Genome Engineering, University of Minnesota, Minneapolis, MN 55455, USA
| | - Jacob D. Jensen
- Department of Pediatrics, University of Minnesota, Minneapolis, MN 55455, USA
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA
- Center for Genome Engineering, University of Minnesota, Minneapolis, MN 55455, USA
| | - Joseph J. Peterson
- Department of Pediatrics, University of Minnesota, Minneapolis, MN 55455, USA
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA
- Center for Genome Engineering, University of Minnesota, Minneapolis, MN 55455, USA
| | - Jason B. Bell
- Department of Pediatrics, University of Minnesota, Minneapolis, MN 55455, USA
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA
- Center for Genome Engineering, University of Minnesota, Minneapolis, MN 55455, USA
| | - Beau R. Webber
- Department of Pediatrics, University of Minnesota, Minneapolis, MN 55455, USA
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA
- Center for Genome Engineering, University of Minnesota, Minneapolis, MN 55455, USA
- Stem Cell Institute, University of Minnesota, Minneapolis, MN 55455, USA
| | - Branden S. Moriarity
- Department of Pediatrics, University of Minnesota, Minneapolis, MN 55455, USA
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA
- Center for Genome Engineering, University of Minnesota, Minneapolis, MN 55455, USA
- Stem Cell Institute, University of Minnesota, Minneapolis, MN 55455, USA
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10
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Mi X, Chen ABY, Duarte D, Carey E, Taylor CR, Braaker PN, Bright M, Almeida RG, Lim JX, Ruetten VMS, Zheng W, Wang M, Reitman ME, Wang Y, Poskanzer KE, Lyons DA, Nimmerjahn A, Ahrens MB, Yu G. Fast, Accurate, and Versatile Data Analysis Platform for the Quantification of Molecular Spatiotemporal Signals. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.02.592259. [PMID: 38766026 PMCID: PMC11100599 DOI: 10.1101/2024.05.02.592259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Optical recording of intricate molecular dynamics is becoming an indispensable technique for biological studies, accelerated by the development of new or improved biosensors and microscopy technology. This creates major computational challenges to extract and quantify biologically meaningful spatiotemporal patterns embedded within complex and rich data sources, many of which cannot be captured with existing methods. Here, we introduce Activity Quantification and Analysis (AQuA2), a fast, accurate, and versatile data analysis platform built upon advanced machine learning techniques. It decomposes complex live imaging-based datasets into elementary signaling events, allowing accurate and unbiased quantification of molecular activities and identification of consensus functional units. We demonstrate applications across a wide range of biosensors, cell types, organs, animal models, and imaging modalities. As exemplar findings, we show how AQuA2 identified drug-dependent interactions between neurons and astroglia, and distinct sensorimotor signal propagation patterns in the mouse spinal cord.
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Affiliation(s)
- Xuelong Mi
- Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Arlington, VA 22203, USA
- These authors contributed equally
| | - Alex Bo-Yuan Chen
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
- Graduate Program in Neuroscience, Harvard Medical School, Boston, MA 02115, USA
- These authors contributed equally
| | - Daniela Duarte
- Waitt Advanced Biophotonics Center, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Erin Carey
- Waitt Advanced Biophotonics Center, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Charlotte R. Taylor
- Department of Biochemistry & Biophysics, University of California, San Francisco, CA, USA
- Neuroscience Graduate Program, University of California, San Francisco, CA, USA
| | - Philipp N. Braaker
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh BioQuarter, Edinburgh EH16 4SB, UK
| | - Mark Bright
- Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Arlington, VA 22203, USA
| | - Rafael G. Almeida
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh BioQuarter, Edinburgh EH16 4SB, UK
| | - Jing-Xuan Lim
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Virginia M. S. Ruetten
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
- Gatsby Computational Neuroscience Unit, UCL, London W1T 4JG, USA
| | - Wei Zheng
- Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Arlington, VA 22203, USA
| | - Mengfan Wang
- Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Arlington, VA 22203, USA
| | - Michael E. Reitman
- Department of Biochemistry & Biophysics, University of California, San Francisco, CA, USA
- Neuroscience Graduate Program, University of California, San Francisco, CA, USA
| | - Yizhi Wang
- Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Arlington, VA 22203, USA
| | - Kira E. Poskanzer
- Department of Biochemistry & Biophysics, University of California, San Francisco, CA, USA
- Neuroscience Graduate Program, University of California, San Francisco, CA, USA
- Kavli Institute for Fundamental Neuroscience, San Francisco, CA, USA
| | - David A. Lyons
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh BioQuarter, Edinburgh EH16 4SB, UK
| | - Axel Nimmerjahn
- Waitt Advanced Biophotonics Center, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Misha B. Ahrens
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Guoqiang Yu
- Department of Automation, Tsinghua University, Beijing 100084, China
- IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China
- Lead contact
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11
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Reinhart KM, Morton RA, Brennan KC, Carlson AP, Shuttleworth CW. Ketamine improves neuronal recovery following spreading depolarization in peri-infarct tissues. J Neurochem 2024; 168:855-867. [PMID: 37596720 PMCID: PMC10986311 DOI: 10.1111/jnc.15923] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 06/10/2023] [Accepted: 07/06/2023] [Indexed: 08/20/2023]
Abstract
Spreading depolarization (SD) has emerged as an important contributor to the enlargement of acute brain injuries. We previously showed that the N-methyl-D-aspartate receptor antagonist ketamine was able to prevent deleterious consequences of SD in brain slices, under conditions of metabolic compromise. The current study aimed to extend these observations into an in vivo stroke model, to test whether gradients of metabolic capacity lead to differential accumulation of calcium (Ca2+) following SD. In addition, we tested whether ketamine protects vulnerable tissuewhile allowing SD to propagate through surrounding undamaged tissue. Focal lesions were generated using a distal middle cerebral artery occlusion in mice, and clusters of SD were generated at 20 min intervals with remote microinjection of potassium chloride. SDs invading peri-infarct regions had significantly different consequences, depending on the distance from the infarct core. Proximal to the lesion, Ca2+ transients were extended, as compared with responses in better-perfused tissue more remote from the lesion. Extracellular potential shifts were also longer and hyperemia responses were reduced in proximal regions following SDs. Consistent with in vitro studies, ketamine, at concentrations that did not abolish the propagation of SD, reduced the accumulation of intracellular Ca2+ in proximal regions following an SD wave. These findings suggest that deleterious consequences of SD can be targeted in vivo, without requiring outright block of SD initiation and propagation.
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Affiliation(s)
- Katelyn M Reinhart
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, New Mexico, USA
- Department of Neurology, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Russell A Morton
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, New Mexico, USA
| | - K C Brennan
- Department of Neurology, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Andrew P Carlson
- Department of Neurosurgery, University of New Mexico, Albuquerque, New Mexico, USA
| | - C William Shuttleworth
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, New Mexico, USA
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12
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Seeholzer LF, Julius D. Neuroendocrine cells initiate protective upper airway reflexes. Science 2024; 384:295-301. [PMID: 38669574 PMCID: PMC11407116 DOI: 10.1126/science.adh5483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 02/21/2024] [Indexed: 04/28/2024]
Abstract
Airway neuroendocrine (NE) cells have been proposed to serve as specialized sensory epithelial cells that modulate respiratory behavior by communicating with nearby nerve endings. However, their functional properties and physiological roles in the healthy lung, trachea, and larynx remain largely unknown. In this work, we show that murine NE cells in these compartments have distinct biophysical properties but share sensitivity to two commonly aspirated noxious stimuli, water and acid. Moreover, we found that tracheal and laryngeal NE cells protect the airways by releasing adenosine 5'-triphosphate (ATP) to activate purinoreceptive sensory neurons that initiate swallowing and expiratory reflexes. Our work uncovers the broad molecular and biophysical diversity of NE cells across the airways and reveals mechanisms by which these specialized excitable cells serve as sentinels for activating protective responses.
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Affiliation(s)
- Laura F. Seeholzer
- Department of Physiology, University of California, San Francisco; San Francisco, 94143, USA
| | - David Julius
- Department of Physiology, University of California, San Francisco; San Francisco, 94143, USA
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13
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Du X, Weng X, Lyu B, Zhao L, Wang H. Localized calcium transients in phragmoplast regulate cytokinesis of tobacco BY-2 cells. PLANT CELL REPORTS 2024; 43:97. [PMID: 38488911 DOI: 10.1007/s00299-024-03181-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Accepted: 02/22/2024] [Indexed: 03/17/2024]
Abstract
KEY MESSAGE Plants exhibit a unique pattern of cytosolic Ca2+ dynamics to correlate with microtubules to regulate cytokinesis, which significantly differs from those observed in animal and yeast cells. Calcium (Ca2+) transients mediated signaling is known to be essential in cytokinesis across eukaryotic cells. However, the detailed spatiotemporal dynamics of Ca2+ during plant cytokinesis remain largely unexplored. In this study, we employed GCaMP5, a genetically encoded Ca2+ sensor, to investigate cytokinetic Ca2+ transients during cytokinesis in Nicotiana tabacum Bright Yellow-2 (BY-2) cells. We validated the effectiveness of GCaMP5 to capture fluctuations in intracellular free Ca2+ in transgenic BY-2 cells. Our results reveal that Ca2+ dynamics during BY-2 cell cytokinesis are distinctly different from those observed in embryonic and yeast cells. It is characterized by an initial significant Ca2+ spike within the phragmoplast region. This spike is followed by a decrease in Ca2+ concentration at the onset of cytokinesis in phragmoplast, which then remains elevated in comparison to the cytosolic Ca2+ until the completion of cell plate formation. At the end of cytokinesis, Ca2+ becomes uniformly distributed in the cytosol. This pattern contrasts with the typical dual waves of Ca2+ spikes observed during cytokinesis in animal embryonic cells and fission yeasts. Furthermore, applications of pharmaceutical inhibitors for either Ca2+ or microtubules revealed a close correlation between Ca2+ transients and microtubule organization in the regulation of cytokinesis. Collectively, our findings highlight the unique dynamics and crucial role of Ca2+ transients during plant cell cytokinesis, and provides new insights into plant cell division mechanisms.
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Affiliation(s)
- Xiaojuan Du
- Department of Cell and Developmental Biology, College of Life Sciences, South China Agricultural University, Guangzhou, 510642, China
| | - Xun Weng
- Department of Cell and Developmental Biology, College of Life Sciences, South China Agricultural University, Guangzhou, 510642, China
| | - Binyang Lyu
- Department of Cell and Developmental Biology, College of Life Sciences, South China Agricultural University, Guangzhou, 510642, China
| | - Lifeng Zhao
- Department of Cell and Developmental Biology, College of Life Sciences, South China Agricultural University, Guangzhou, 510642, China
| | - Hao Wang
- Department of Cell and Developmental Biology, College of Life Sciences, South China Agricultural University, Guangzhou, 510642, China.
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14
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Sharifi KA, Farzad F, Soldozy S, DeWitt MR, Price RJ, Sheehan J, Kalani MYS, Tvrdik P. Exploring the dynamics of adult Axin2 cell lineage integration into dentate gyrus granule neurons. Front Neurosci 2024; 18:1353142. [PMID: 38449734 PMCID: PMC10915230 DOI: 10.3389/fnins.2024.1353142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Accepted: 01/31/2024] [Indexed: 03/08/2024] Open
Abstract
The Wnt pathway plays critical roles in neurogenesis. The expression of Axin2 is induced by Wnt/β-catenin signaling, making this gene a reliable indicator of canonical Wnt activity. We employed pulse-chase genetic lineage tracing with the Axin2-CreERT2 allele to follow the fate of Axin2+ lineage in the adult hippocampal formation. We found Axin2 expressed in astrocytes, neurons and endothelial cells, as well as in the choroid plexus epithelia. Simultaneously with the induction of Axin2 fate mapping by tamoxifen, we marked the dividing cells with 5-ethynyl-2'-deoxyuridine (EdU). Tamoxifen induction led to a significant increase in labeled dentate gyrus granule cells three months later. However, none of these neurons showed any EdU signal. Conversely, six months after the pulse-chase labeling with tamoxifen/EdU, we identified granule neurons that were positive for both EdU and tdTomato lineage tracer in each animal. Our data indicates that Axin2 is expressed at multiple stages of adult granule neuron differentiation. Furthermore, these findings suggest that the integration process of adult-born neurons from specific cell lineages may require more time than previously thought.
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Affiliation(s)
- Khadijeh A Sharifi
- Department of Neurological Surgery, University of Virginia Health System, Charlottesville, VA, United States
- Department of Neuroscience, University of Virginia, Charlottesville, VA, United States
| | - Faraz Farzad
- Department of Neurological Surgery, University of Virginia Health System, Charlottesville, VA, United States
| | - Sauson Soldozy
- Department of Neurological Surgery, University of Virginia Health System, Charlottesville, VA, United States
- Department of Neurosurgery, Westchester Medical Center and New York Medical College, Valhalla, NY, United States
| | - Matthew R DeWitt
- Department of Focused Ultrasound Cancer Immunotherapy Center, University of Virginia, Charlottesville, VA, United States
| | - Richard J Price
- Biomedical Engineering, University of Virginia, Charlottesville, VA, United States
| | - Jason Sheehan
- Department of Neurological Surgery, University of Virginia Health System, Charlottesville, VA, United States
| | - M Yashar S Kalani
- Department of Neurological Surgery, University of Virginia Health System, Charlottesville, VA, United States
- Department of Neuroscience, University of Virginia, Charlottesville, VA, United States
- School of Medicine, St. John's Neuroscience Institute, University of Oklahoma, Tulsa, OK, United States
| | - Petr Tvrdik
- Department of Neurological Surgery, University of Virginia Health System, Charlottesville, VA, United States
- Department of Neuroscience, University of Virginia, Charlottesville, VA, United States
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15
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Izquierdo P, Jolivet RB, Attwell D, Madry C. Amyloid plaques and normal ageing have differential effects on microglial Ca 2+ activity in the mouse brain. Pflugers Arch 2024; 476:257-270. [PMID: 37966547 PMCID: PMC10791787 DOI: 10.1007/s00424-023-02871-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 10/02/2023] [Accepted: 10/24/2023] [Indexed: 11/16/2023]
Abstract
In microglia, changes in intracellular calcium concentration ([Ca2+]i) may regulate process motility, inflammasome activation, and phagocytosis. However, while neurons and astrocytes exhibit frequent spontaneous Ca2+ activity, microglial Ca2+ signals are much rarer and poorly understood. Here, we studied [Ca2+]i changes of microglia in acute brain slices using Fluo-4-loaded cells and mice expressing GCaMP5g in microglia. Spontaneous Ca2+ transients occurred ~ 5 times more frequently in individual microglial processes than in their somata. We assessed whether microglial Ca2+ responses change in Alzheimer's disease (AD) using AppNL-G-F knock-in mice. Proximity to Aβ plaques strongly affected microglial Ca2+ activity. Although spontaneous Ca2+ transients were unaffected in microglial processes, they were fivefold more frequent in microglial somata near Aβ plaques than in wild-type microglia. Microglia away from Aβ plaques in AD mice showed intermediate properties for morphology and Ca2+ responses, partly resembling those of wild-type microglia. By contrast, somatic Ca2+ responses evoked by tissue damage were less intense in microglia near Aβ plaques than in wild-type microglia, suggesting different mechanisms underlying spontaneous vs. damage-evoked Ca2+ signals. Finally, as similar processes occur in neurodegeneration and old age, we studied whether ageing affected microglial [Ca2+]i. Somatic damage-evoked Ca2+ responses were greatly reduced in microglia from old mice, as in the AD mice. In contrast to AD, however, old age did not alter the occurrence of spontaneous Ca2+ signals in microglial somata but reduced the rate of events in processes. Thus, we demonstrate distinct compartmentalised Ca2+ activity in microglia from healthy, aged and AD-like brains.
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Affiliation(s)
- Pablo Izquierdo
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, WC1E 6BT, UK
| | - Renaud B Jolivet
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, WC1E 6BT, UK
- Maastricht Centre for Systems Biology (MaCSBio), Maastricht University, Paul-Henri Spaaklaan 1, 6229 EN, Maastricht, The Netherlands
| | - David Attwell
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, WC1E 6BT, UK.
| | - Christian Madry
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, WC1E 6BT, UK.
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität Zu Berlin, Institute of Neurophysiology, 10117, Berlin, Germany.
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16
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Masala N, Mittag M, Giovannetti EA, O'Neil DA, Distler F, Rupprecht P, Helmchen F, Yuste R, Fuhrmann M, Beck H, Wenzel M, Kelly T. Aberrant hippocampal Ca 2+ micro-waves following synapsin-dependent adeno-associated viral expression of Ca 2+ indicators. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.11.08.566169. [PMID: 37986838 PMCID: PMC10659308 DOI: 10.1101/2023.11.08.566169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Genetically encoded calcium indicators (GECIs) such as GCaMP are invaluable tools in neuroscience to monitor neuronal activity using optical imaging. The viral transduction of GECIs is commonly used to target expression to specific brain regions, can be conveniently used with any mouse strain of interest without the need for prior crossing with a GECI mouse line and avoids potential hazards due to the chronic expression of GECIs during development. A key requirement for monitoring neuronal activity with an indicator is that the indicator itself minimally affects activity. Here, using common adeno-associated viral (AAV) transduction procedures, we describe spatially confined aberrant Ca2+ micro-waves slowly travelling through the hippocampus following expression of GCaMP6, GCaMP7 or R-CaMP1.07 driven by the synapsin promoter with AAV-dependent gene transfer, in a titre-dependent fashion. Ca2+ micro-waves developed in hippocampal CA1 and CA3, but not dentate gyrus (DG) nor neocortex, were typically first observed at 4 weeks after viral transduction, and persisted up to at least 8 weeks. The phenomenon was robust, observed across laboratories with various experimenters and setups. Our results indicate that aberrant hippocampal Ca2+ micro-waves depend on the promoter and viral titre of the GECI, density of expression as well as the targeted brain region. We used an alternative viral transduction method of GCaMP which avoids this artifact. The results show that commonly used Ca2+-indicator AAV transduction procedures can produce artefactual Ca2+ responses. Our aim is to raise awareness in the field of these artefactual transduction-induced Ca2+ micro-waves and we provide a potential solution.
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Affiliation(s)
- Nicola Masala
- University of Bonn, Faculty of Medicine, Institute for Experimental Epileptology and Cognition Research (IEECR), Bonn, Germany
- University Hospital Bonn
- Department of Epileptology, University Hospital Bonn, Bonn, Germany
| | - Manuel Mittag
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | | | - Darik A O'Neil
- NeuroTechnology Center, Columbia University, New York, NY, USA
| | - Fabian Distler
- University of Bonn, Faculty of Medicine, Institute for Experimental Epileptology and Cognition Research (IEECR), Bonn, Germany
- University Hospital Bonn
| | - Peter Rupprecht
- Brain Research Institute, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
| | - Fritjof Helmchen
- Brain Research Institute, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
| | - Rafael Yuste
- NeuroTechnology Center, Columbia University, New York, NY, USA
| | - Martin Fuhrmann
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Heinz Beck
- University of Bonn, Faculty of Medicine, Institute for Experimental Epileptology and Cognition Research (IEECR), Bonn, Germany
- University Hospital Bonn
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Michael Wenzel
- University of Bonn, Faculty of Medicine, Institute for Experimental Epileptology and Cognition Research (IEECR), Bonn, Germany
- University Hospital Bonn
- Department of Epileptology, University Hospital Bonn, Bonn, Germany
| | - Tony Kelly
- University of Bonn, Faculty of Medicine, Institute for Experimental Epileptology and Cognition Research (IEECR), Bonn, Germany
- University Hospital Bonn
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17
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Crockett A, Fuhrmann M, Garaschuk O, Davalos D. Progress in Structural and Functional In Vivo Imaging of Microglia and Their Application in Health and Disease. ADVANCES IN NEUROBIOLOGY 2024; 37:65-80. [PMID: 39207687 DOI: 10.1007/978-3-031-55529-9_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
The first line of defense for the central nervous system (CNS) against injury or disease is provided by microglia. Microglia were long believed to stay in a dormant/resting state, reacting only to injury or disease. This view changed dramatically with the development of modern imaging techniques that allowed the study of microglial behavior in the intact brain over time, to reveal the dynamic nature of their responses. Over the past two decades, in vivo imaging using multiphoton microscopy has revealed numerous new functions of microglia in the developing, adult, aged, injured, and diseased CNS. As the most dynamic cells in the brain, microglia continuously contact all structures and cell types, such as glial and vascular cells, neuronal cell bodies, axons, dendrites, and dendritic spines, and are believed to play a central role in sculpting neuronal networks throughout life. Following trauma, or in neurodegenerative or neuroinflammatory diseases, microglial responses range from protective to harmful, underscoring the need to better understand their diverse roles and states in different pathological conditions. In this chapter, we introduce multiphoton microscopy and discuss recent advances in structural and functional imaging technologies that have expanded our toolbox to study microglial states and behaviors in new ways and depths. We also discuss relevant mouse models available for in vivo imaging studies of microglia and review how such studies are constantly refining our understanding of the multifaceted role of microglia in the healthy and diseased CNS.
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Affiliation(s)
- Alexis Crockett
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Martin Fuhrmann
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Olga Garaschuk
- Institute of Physiology, Department of Neurophysiology, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Dimitrios Davalos
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA.
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH, USA.
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18
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Sharifi KA, Farzad F, Soldozy S, Price RJ, Kalani MYS, Tvrdik P. Dynamics of Adult Axin2 Cell Lineage Integration in Granule Neurons of the Dentate Gyrus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.09.570930. [PMID: 38106115 PMCID: PMC10723478 DOI: 10.1101/2023.12.09.570930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
The Wnt pathway plays critical roles in neurogenesis. The expression of Axin2 is induced by Wnt/β-catenin signaling, making this gene a sensitive indicator of canonical Wnt activity. We employed pulse-chase genetic lineage tracing with the Axin2-CreERT2 allele to follow the fate of Axin2 -positive cells in the adult hippocampal formation. We found Axin2 expressed in astrocytes, neurons and endothelial cells, as well as in the choroid plexus epithelia. Simultaneously with tamoxifen induction of Axin2 fate mapping, the dividing cells were marked with 5-ethynyl-2'-deoxyuridine (EdU). Tamoxifen induction resulted in significant increase of dentate gyrus granule cells three months later; however, none of these neurons contained EdU signal. Conversely, six months after the tamoxifen/EdU pulse-chase labeling, EdU-positive granule neurons were identified in each animal. Our data imply that Axin2 is expressed at several different stages of adult granule neuron differentiation and suggest that the process of integration of the adult-born neurons from certain cell lineages may take longer than previously thought.
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19
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Wan Y, Edmond MA, Kitz C, Southern J, Holman HA. An integrated workflow for 2D and 3D posture analysis during vestibular system testing in mice. Front Neurol 2023; 14:1281790. [PMID: 38107632 PMCID: PMC10722188 DOI: 10.3389/fneur.2023.1281790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 11/07/2023] [Indexed: 12/19/2023] Open
Abstract
Introduction Posture extraction from videos is fundamental to many real-world applications, including health screenings. In this study, we extend the utility and specificity of a well-established protocol, the balance beam, for examining balance and active motor coordination in adult mice of both sexes. Objectives The primary objective of this study is to design a workflow for analyzing the postures of mice walking on a balance beam. Methods We developed new tools and scripts based on the FluoRender architecture, which can interact with DeepLabCut (DLC) through Python code. Notably, twenty input videos were divided into four feature point groups (head, body, tail, and feet), based on camera positions relative to the balance beam (left and right), and viewing angles (90° and 45° from the beam). We determined key feature points on the mouse to track posture in a still video frame. We extracted a standard walk cycle (SWC) by focusing on foot movements, which were computed by a weighted average of the extracted walk cycles. The correlation of each walk cycle to the SWC was used as the weight. Results We learned that positions of the camera angles significantly improved the performance of 2D pose estimation (90°) and 3D (45°). Comparing the SWCs from age-matched mice, we found a consistent pattern of supporting feet on the beam. Two feet were consistently on the beam followed by three feet and another three feet in a 2-3-3 pattern. However, this pattern can be mirrored among individual subjects. A subtle phase shift of foot movement was also observed from the SWCs. Furthermore, we compared the SWCs with speed values to reveal anomalies in mouse walk postures. Some anomalies can be explained as the start or finish of the traversal, while others may be correlated to the distractions of the test environment, which will need further investigation. Conclusion Our posture analysis workflow improves the classical behavioral testing and analysis, allowing the detection of subtle, but significant differences in vestibular function and motor coordination.
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Affiliation(s)
- Yong Wan
- Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT, United States
| | - Michaela A. Edmond
- Department of Neurology, University of Utah, Salt Lake City, UT, United States
| | - Colin Kitz
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, United States
| | - Joseph Southern
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, United States
| | - Holly A. Holman
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, United States
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20
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Pekayvaz K, Gold C, Hoseinpour P, Engel A, Martinez-Navarro A, Eivers L, Coletti R, Joppich M, Dionísio F, Kaiser R, Tomas L, Janjic A, Knott M, Mehari F, Polewka V, Kirschner M, Boda A, Nicolai L, Schulz H, Titova A, Kilani B, Lorenz M, Fingerle-Rowson G, Bucala R, Enard W, Zimmer R, Weber C, Libby P, Schulz C, Massberg S, Stark K. Mural cell-derived chemokines provide a protective niche to safeguard vascular macrophages and limit chronic inflammation. Immunity 2023; 56:2325-2341.e15. [PMID: 37652021 PMCID: PMC10588993 DOI: 10.1016/j.immuni.2023.08.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 06/23/2023] [Accepted: 08/03/2023] [Indexed: 09/02/2023]
Abstract
Maladaptive, non-resolving inflammation contributes to chronic inflammatory diseases such as atherosclerosis. Because macrophages remove necrotic cells, defective macrophage programs can promote chronic inflammation with persistent tissue injury. Here, we investigated the mechanisms sustaining vascular macrophages. Intravital imaging revealed a spatiotemporal macrophage niche across vascular beds alongside mural cells (MCs)-pericytes and smooth muscle cells. Single-cell transcriptomics, co-culture, and genetic deletion experiments revealed MC-derived expression of the chemokines CCL2 and MIF, which actively preserved macrophage survival and their homeostatic functions. In atherosclerosis, this positioned macrophages in viable plaque areas, away from the necrotic core, and maintained a homeostatic macrophage phenotype. Disruption of this MC-macrophage unit via MC-specific deletion of these chemokines triggered detrimental macrophage relocalizing, exacerbated plaque necrosis, inflammation, and atheroprogression. In line, CCL2 inhibition at advanced stages of atherosclerosis showed detrimental effects. This work presents a MC-driven safeguard toward maintaining the homeostatic vascular macrophage niche.
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Affiliation(s)
- Kami Pekayvaz
- Medizinische Klinik und Poliklinik I, LMU University Hospital, LMU Munich, Munich, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich, Germany.
| | - Christoph Gold
- Medizinische Klinik und Poliklinik I, LMU University Hospital, LMU Munich, Munich, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich, Germany
| | - Parandis Hoseinpour
- Medizinische Klinik und Poliklinik I, LMU University Hospital, LMU Munich, Munich, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich, Germany
| | - Anouk Engel
- Medizinische Klinik und Poliklinik I, LMU University Hospital, LMU Munich, Munich, Germany
| | | | - Luke Eivers
- Medizinische Klinik und Poliklinik I, LMU University Hospital, LMU Munich, Munich, Germany
| | - Raffaele Coletti
- Medizinische Klinik und Poliklinik I, LMU University Hospital, LMU Munich, Munich, Germany
| | - Markus Joppich
- Department of Informatics, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Flávio Dionísio
- Medizinische Klinik und Poliklinik I, LMU University Hospital, LMU Munich, Munich, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich, Germany
| | - Rainer Kaiser
- Medizinische Klinik und Poliklinik I, LMU University Hospital, LMU Munich, Munich, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich, Germany
| | - Lukas Tomas
- Medizinische Klinik und Poliklinik I, LMU University Hospital, LMU Munich, Munich, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich, Germany
| | - Aleksandar Janjic
- Anthropology and Human Genomics, Faculty of Biology, Ludwig-Maximilians University, Munich, Germany
| | - Maximilian Knott
- Institute of Pathology, Ludwig-Maximilian University Munich, Munich, Germany
| | - Fitsumbirhan Mehari
- Medizinische Klinik und Poliklinik I, LMU University Hospital, LMU Munich, Munich, Germany
| | - Vivien Polewka
- Medizinische Klinik und Poliklinik I, LMU University Hospital, LMU Munich, Munich, Germany
| | - Megan Kirschner
- Medizinische Klinik und Poliklinik I, LMU University Hospital, LMU Munich, Munich, Germany
| | - Annegret Boda
- Medizinische Klinik und Poliklinik I, LMU University Hospital, LMU Munich, Munich, Germany
| | - Leo Nicolai
- Medizinische Klinik und Poliklinik I, LMU University Hospital, LMU Munich, Munich, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich, Germany
| | - Heiko Schulz
- Institute of Pathology, Ludwig-Maximilian University Munich, Munich, Germany
| | - Anna Titova
- Medizinische Klinik und Poliklinik I, LMU University Hospital, LMU Munich, Munich, Germany
| | - Badr Kilani
- Medizinische Klinik und Poliklinik I, LMU University Hospital, LMU Munich, Munich, Germany
| | - Michael Lorenz
- Medizinische Klinik und Poliklinik I, LMU University Hospital, LMU Munich, Munich, Germany
| | | | - Richard Bucala
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Wolfgang Enard
- Anthropology and Human Genomics, Faculty of Biology, Ludwig-Maximilians University, Munich, Germany
| | - Ralf Zimmer
- Department of Informatics, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Christian Weber
- DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich, Germany; Institute for Cardiovascular Prevention (IPEK), Ludwig-Maximillian-Universität (LMU) München, Munich Cluster for Systems Neurology (SyNergy), Munich, Germany; Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, the Netherlands
| | - Peter Libby
- Division of Cardiovascular Medicine, Brigham and Women's Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Christian Schulz
- Medizinische Klinik und Poliklinik I, LMU University Hospital, LMU Munich, Munich, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich, Germany
| | - Steffen Massberg
- Medizinische Klinik und Poliklinik I, LMU University Hospital, LMU Munich, Munich, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich, Germany
| | - Konstantin Stark
- Medizinische Klinik und Poliklinik I, LMU University Hospital, LMU Munich, Munich, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich, Germany.
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21
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Mazzotta E, Grants I, Villalobos-Hernandez E, Chaudhuri S, McClain JL, Seguella L, Kendig DM, Blakeney BA, Murthy SK, Schneider R, Leven P, Wehner S, Harzman A, Grider JR, Gulbransen BD, Christofi FL. BQ788 reveals glial ET B receptor modulation of neuronal cholinergic and nitrergic pathways to inhibit intestinal motility: Linked to postoperative ileus. Br J Pharmacol 2023; 180:2550-2576. [PMID: 37198101 PMCID: PMC11085045 DOI: 10.1111/bph.16145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 05/03/2023] [Accepted: 05/05/2023] [Indexed: 05/19/2023] Open
Abstract
BACKGROUND AND PURPOSE ET-1 signalling modulates intestinal motility and inflammation, but the role of ET-1/ETB receptor signalling is poorly understood. Enteric glia modulate normal motility and inflammation. We investigated whether glial ETB signalling regulates neural-motor pathways of intestinal motility and inflammation. EXPERIMENTAL APPROACH We studied ETB signalling using: ETB drugs (ET-1, SaTX, BQ788), activity-dependent stimulation of neurons (high K+ -depolarization, EFS), gliotoxins, Tg (Ednrb-EGFP)EP59Gsat/Mmucd mice, cell-specific mRNA in Sox10CreERT2 ;Rpl22-HAflx or ChATCre ;Rpl22-HAflx mice, Sox10CreERT2 ::GCaMP5g-tdT, Wnt1Cre2 ::GCaMP5g-tdT mice, muscle tension recordings, fluid-induced peristalsis, ET-1 expression, qPCR, western blots, 3-D LSM-immunofluorescence co-labelling studies in LMMP-CM and a postoperative ileus (POI) model of intestinal inflammation. KEY RESULTS In the muscularis externa ETB receptor is expressed exclusively in glia. ET-1 is expressed in RiboTag (ChAT)-neurons, isolated ganglia and intra-ganglionic varicose-nerve fibres co-labelled with peripherin or SP. ET-1 release provides activity-dependent glial ETB receptor modulation of Ca2+ waves in neural evoked glial responses. BQ788 reveals amplification of glial and neuronal Ca2+ responses and excitatory cholinergic contractions, sensitive to L-NAME. Gliotoxins disrupt SaTX-induced glial-Ca2+ waves and prevent BQ788 amplification of contractions. The ETB receptor is linked to inhibition of contractions and peristalsis. Inflammation causes glial ETB up-regulation, SaTX-hypersensitivity and glial amplification of ETB signalling. In vivo BQ788 (i.p., 1 mg·kg-1 ) attenuates intestinal inflammation in POI. CONCLUSION AND IMPLICATIONS Enteric glial ET-1/ETB signalling provides dual modulation of neural-motor circuits to inhibit motility. It inhibits excitatory cholinergic and stimulates inhibitory nitrergic motor pathways. Amplification of glial ETB receptors is linked to muscularis externa inflammation and possibly pathogenic mechanisms of POI.
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Affiliation(s)
- Elvio Mazzotta
- Department of Anesthesiology, Wexner Medical Center, The Ohio State University, Columbus, Ohio, USA
| | - Iveta Grants
- Department of Anesthesiology, Wexner Medical Center, The Ohio State University, Columbus, Ohio, USA
| | | | - Samhita Chaudhuri
- Department of Anesthesiology, Wexner Medical Center, The Ohio State University, Columbus, Ohio, USA
| | - Jonathon L McClain
- Department of Physiology, Michigan State University, East Lansing, Michigan, USA
| | - Luisa Seguella
- Department of Physiology and Pharmacology "V. Erspamer", Sapienza University of Rome, Rome, Italy
| | - Derek M Kendig
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Bryan A Blakeney
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Srinivasa K Murthy
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, Virginia, USA
| | | | - Patrick Leven
- Department of Surgery, University of Bonn, Bonn, Germany
| | - Sven Wehner
- Department of Surgery, University of Bonn, Bonn, Germany
| | - Alan Harzman
- Department of GI Surgery, Wexner Medical Center, The Ohio State University, Columbus, Ohio, USA
| | - John R Grider
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Brian D Gulbransen
- Department of Physiology, Michigan State University, East Lansing, Michigan, USA
| | - Fedias L Christofi
- Department of Anesthesiology, Wexner Medical Center, The Ohio State University, Columbus, Ohio, USA
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22
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Wu X, Li JR, Fu Y, Chen DY, Nie H, Tang ZP. From static to dynamic: live observation of the support system after ischemic stroke by two photon-excited fluorescence laser-scanning microscopy. Neural Regen Res 2023; 18:2093-2107. [PMID: 37056116 PMCID: PMC10328295 DOI: 10.4103/1673-5374.369099] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 12/21/2022] [Accepted: 01/13/2023] [Indexed: 02/17/2023] Open
Abstract
Ischemic stroke is one of the most common causes of mortality and disability worldwide. However, treatment efficacy and the progress of research remain unsatisfactory. As the critical support system and essential components in neurovascular units, glial cells and blood vessels (including the blood-brain barrier) together maintain an optimal microenvironment for neuronal function. They provide nutrients, regulate neuronal excitability, and prevent harmful substances from entering brain tissue. The highly dynamic networks of this support system play an essential role in ischemic stroke through processes including brain homeostasis, supporting neuronal function, and reacting to injuries. However, most studies have focused on postmortem animals, which inevitably lack critical information about the dynamic changes that occur after ischemic stroke. Therefore, a high-precision technique for research in living animals is urgently needed. Two-photon fluorescence laser-scanning microscopy is a powerful imaging technique that can facilitate live imaging at high spatiotemporal resolutions. Two-photon fluorescence laser-scanning microscopy can provide images of the whole-cortex vascular 3D structure, information on multicellular component interactions, and provide images of structure and function in the cranial window. This technique shifts the existing research paradigm from static to dynamic, from flat to stereoscopic, and from single-cell function to multicellular intercommunication, thus providing direct and reliable evidence to identify the pathophysiological mechanisms following ischemic stroke in an intact brain. In this review, we discuss exciting findings from research on the support system after ischemic stroke using two-photon fluorescence laser-scanning microscopy, highlighting the importance of dynamic observations of cellular behavior and interactions in the networks of the brain's support systems. We show the excellent application prospects and advantages of two-photon fluorescence laser-scanning microscopy and predict future research developments and directions in the study of ischemic stroke.
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Affiliation(s)
- Xuan Wu
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
| | - Jia-Rui Li
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
| | - Yu Fu
- Department of Geriatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
| | - Dan-Yang Chen
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
| | - Hao Nie
- Department of Geriatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
| | - Zhou-Ping Tang
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
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23
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Yue WWS, Touhara KK, Toma K, Duan X, Julius D. Endogenous Opioid Signaling Regulates Proliferation of Spinal Cord Ependymal Cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.07.556726. [PMID: 38883735 PMCID: PMC11178014 DOI: 10.1101/2023.09.07.556726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2024]
Abstract
After injury, mammalian spinal cords develop scars to seal off the damaged area and prevent further injury. However, excessive scarring can hinder neural regeneration and functional recovery (1, 2). These competing actions underscore the importance of developing therapeutic strategies to dynamically modulate the extent of scar formation. Previous research on scar formation has primarily focused on the role of astrocytes, but recent evidence suggests that ependymal cells also participate. Ependymal cells normally form the epithelial layer encasing the central canal, but they undergo massive proliferation and differentiation into astroglia following certain types of injury, becoming a core component of scars (3-7). However, the mechanisms regulating ependymal proliferation in vivo in both healthy and injured conditions remain unclear. Here, we uncover an intercellular kappa (κ) opioid signaling pathway that controls endogenous ependymal proliferation. Specifically, we detect expression of the κ opioid receptor, OPRK1, in a functionally under-characterized cell type called cerebrospinal fluid-contacting neurons (CSF-cNs). We also discover a neighboring cell population that express the cognate ligand, prodynorphin (PDYN). Importantly, OPRK1 activation excites CSF-cNs, and systemic administration of a κ antagonist enhances ependymal proliferation in uninjured spinal cords in a CSF-cN-dependent manner. Moreover, injecting a κ agonist reduces the proliferation induced by dorsal hemisection. Altogether, our data suggest a regulatory mechanism whereby PDYN + cells tonically release κ opioids to stimulate CSF-cNs, which in turn suppress ependymal proliferation. This endogenous pathway provides a mechanistic basis for the potential use of κ opiates in modulating scar formation and treating spinal cord injuries.
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24
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Korte N, James G, You H, Hirunpattarasilp C, Christie I, Sethi H, Attwell D. Noradrenaline released from locus coeruleus axons contracts cerebral capillary pericytes via α2 adrenergic receptors. J Cereb Blood Flow Metab 2023; 43:1142-1152. [PMID: 36688515 PMCID: PMC10291462 DOI: 10.1177/0271678x231152549] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 11/15/2022] [Accepted: 01/03/2023] [Indexed: 01/24/2023]
Abstract
Noradrenaline (NA) release from locus coeruleus axons generates vascular contractile tone in arteriolar smooth muscle and contractile capillary pericytes. This tone allows neuronal activity to evoke vasodilation that increases local cerebral blood flow (CBF). Much of the vascular resistance within the brain is located in capillaries and locus coeruleus axons have NA release sites closer to pericytes than to arterioles. In acute brain slices, NA contracted pericytes but did not raise the pericyte cytoplasmic Ca2+ concentration, while the α1 agonist phenylephrine did not evoke contraction. Blocking α2 adrenergic receptors (α2Rs, which induce contraction by inhibiting cAMP production), greatly reduced the NA-evoked pericyte contraction, whereas stimulating α2Rs using xylazine (a sedative) or clonidine (an anti-hypertensive drug) evoked pericyte contraction. Noradrenaline-evoked pericyte contraction and capillary constriction are thus mediated via α2Rs. Consequently, α2Rs may not only modulate CBF in health and pathological conditions, but also contribute to CBF changes evoked by α2R ligands administered in research, veterinary and clinical settings.
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Affiliation(s)
- Nils Korte
- Dept of Neuroscience, Physiology & Pharmacology, University College London, London, UK
| | - Greg James
- Dept of Neuroscience, Physiology & Pharmacology, University College London, London, UK
- Department of Neurosurgery, Great Ormond Street Hospital, London, UK
| | - Haoming You
- Dept of Neuroscience, Physiology & Pharmacology, University College London, London, UK
| | - Chanawee Hirunpattarasilp
- Dept of Neuroscience, Physiology & Pharmacology, University College London, London, UK
- Princess Srisavangavadhana College of Medicine, Chulabhorn Royal Academy, Bangkok, Thailand
| | - Isabel Christie
- Dept of Neuroscience, Physiology & Pharmacology, University College London, London, UK
| | - Huma Sethi
- Dept of Neurosurgery, National Hospital for Neurology and Neurosurgery, London, UK
| | - David Attwell
- Dept of Neuroscience, Physiology & Pharmacology, University College London, London, UK
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25
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Hou B, Santaniello S, Tzingounis AV. KCNQ2 channels regulate the population activity of neonatal GABAergic neurons ex vivo. Front Neurol 2023; 14:1207539. [PMID: 37409016 PMCID: PMC10318362 DOI: 10.3389/fneur.2023.1207539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 05/18/2023] [Indexed: 07/07/2023] Open
Abstract
Over the last decade KCNQ2 channels have arisen as fundamental and indispensable regulators of neonatal brain excitability, with KCNQ2 loss-of-function pathogenic variants being increasingly identified in patients with developmental and epileptic encephalopathy. However, the mechanisms by which KCNQ2 loss-of-function variants lead to network dysfunction are not fully known. An important remaining knowledge gap is whether loss of KCNQ2 function alters GABAergic interneuron activity early in development. To address this question, we applied mesoscale calcium imaging ex vivo in postnatal day 4-7 mice lacking KCNQ2 channels in interneurons (Vgat-ires-cre;Kcnq2f/f;GCamp5). In the presence of elevated extracellular potassium concentrations, ablation of KCNQ2 channels from GABAergic cells increased the interneuron population activity in the hippocampal formation and regions of the neocortex. We found that this increased population activity depends on fast synaptic transmission, with excitatory transmission promoting the activity and GABAergic transmission curtailing it. Together, our data show that loss of function of KCNQ2 channels from interneurons increases the network excitability of the immature GABAergic circuits, revealing a new function of KCNQ2 channels in interneuron physiology in the developing brain.
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Affiliation(s)
- Bowen Hou
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, United States
| | - Sabato Santaniello
- Department of Biomedical Engineering and CT Institute for the Brain and Cognitive Sciences, University of Connecticut, Storrs, CT, United States
| | - Anastasios V. Tzingounis
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, United States
- Department of Biomedical Engineering and CT Institute for the Brain and Cognitive Sciences, University of Connecticut, Storrs, CT, United States
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26
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Sokolowski JD, Soldozy S, Sharifi KA, Norat P, Kearns KN, Liu L, Williams AM, Yağmurlu K, Mastorakos P, Miller GW, Kalani MYS, Park MS, Kellogg RT, Tvrdik P. Preclinical models of middle cerebral artery occlusion: new imaging approaches to a classic technique. Front Neurol 2023; 14:1170675. [PMID: 37409019 PMCID: PMC10318149 DOI: 10.3389/fneur.2023.1170675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 05/30/2023] [Indexed: 07/07/2023] Open
Abstract
Stroke remains a major burden on patients, families, and healthcare professionals, despite major advances in prevention, acute treatment, and rehabilitation. Preclinical basic research can help to better define mechanisms contributing to stroke pathology, and identify therapeutic interventions that can decrease ischemic injury and improve outcomes. Animal models play an essential role in this process, and mouse models are particularly well-suited due to their genetic accessibility and relatively low cost. Here, we review the focal cerebral ischemia models with an emphasis on the middle cerebral artery occlusion technique, a "gold standard" in surgical ischemic stroke models. Also, we highlight several histologic, genetic, and in vivo imaging approaches, including mouse stroke MRI techniques, that have the potential to enhance the rigor of preclinical stroke evaluation. Together, these efforts will pave the way for clinical interventions that can mitigate the negative impact of this devastating disease.
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Affiliation(s)
- Jennifer D. Sokolowski
- Department of Neurological Surgery, University of Virginia, Charlottesville, VA, United States
| | - Sauson Soldozy
- Department of Neurological Surgery, Westchester Medical Center, Valhalla, NY, United States
| | - Khadijeh A. Sharifi
- Department of Neurological Surgery, University of Virginia, Charlottesville, VA, United States
- Department of Neuroscience, University of Virginia, Charlottesville, VA, United States
| | - Pedro Norat
- Department of Neurological Surgery, University of Virginia, Charlottesville, VA, United States
| | - Kathryn N. Kearns
- Department of Neurological Surgery, University of Virginia, Charlottesville, VA, United States
| | - Lei Liu
- Department of Neurological Surgery and Neuroscience, Northwestern University, Chicago, IL, United States
| | - Ashley M. Williams
- School of Medicine, Morsani College of Medicine, Tampa, FL, United States
| | - Kaan Yağmurlu
- Department of Neurological Surgery, University of Tennessee, Memphis, TN, United States
| | - Panagiotis Mastorakos
- Department of Neurological Surgery, Thomas Jefferson University, Philadelphia, PA, United States
| | - G. Wilson Miller
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, United States
| | - M. Yashar S. Kalani
- Department of Neurological Surgery, St. John's Neuroscience Institute, Tulsa, OK, United States
| | - Min S. Park
- Department of Neurological Surgery, University of Virginia, Charlottesville, VA, United States
| | - Ryan T. Kellogg
- Department of Neurological Surgery, University of Virginia, Charlottesville, VA, United States
| | - Petr Tvrdik
- Department of Neurological Surgery, University of Virginia, Charlottesville, VA, United States
- Department of Neuroscience, University of Virginia, Charlottesville, VA, United States
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27
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Rasmussen RN, Asiminas A, Carlsen EMM, Kjaerby C, Smith NA. Astrocytes: integrators of arousal state and sensory context. Trends Neurosci 2023; 46:418-425. [PMID: 37003933 PMCID: PMC10192111 DOI: 10.1016/j.tins.2023.03.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 02/24/2023] [Accepted: 03/05/2023] [Indexed: 04/01/2023]
Abstract
The integration of external information with the internal state of the body is central to the survival of virtually every multicellular organism. However, a complete picture of the mechanisms that govern this process is lacking. In this opinion article, we synthesize evidence demonstrating that astrocytes sense the momentary arousal state - through neuromodulator release - as well as the sensory inputs - through local synaptic activity - and respond to them with changes in calcium (Ca2+) signaling. We hypothesize that astrocytes integrate sensory signals with the internal state and that this process is necessary to secure optimal behavior. Finally, we argue that dysfunctional astrocytic Ca2+ signaling could be an underlying factor in disorders characterized by disrupted sensory processing.
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Affiliation(s)
- Rune Nguyen Rasmussen
- Center for Translational Neuromedicine, University of Copenhagen, 2200 Copenhagen, Denmark.
| | - Antonis Asiminas
- Center for Translational Neuromedicine, University of Copenhagen, 2200 Copenhagen, Denmark
| | | | - Celia Kjaerby
- Center for Translational Neuromedicine, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Nathan Anthony Smith
- Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester, School of Medicine and Dentistry, Rochester, NY 14642, USA.
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An astrocytic signaling loop for frequency-dependent control of dendritic integration and spatial learning. Nat Commun 2022; 13:7932. [PMID: 36566254 PMCID: PMC9789958 DOI: 10.1038/s41467-022-35620-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 12/13/2022] [Indexed: 12/25/2022] Open
Abstract
Dendrites of hippocampal CA1 pyramidal cells amplify clustered glutamatergic input by activation of voltage-gated sodium channels and N-methyl-D-aspartate receptors (NMDARs). NMDAR activity depends on the presence of NMDAR co-agonists such as D-serine, but how co-agonists influence dendritic integration is not well understood. Using combinations of whole-cell patch clamp, iontophoretic glutamate application, two-photon excitation fluorescence microscopy and glutamate uncaging in acute rat and mouse brain slices we found that exogenous D-serine reduced the threshold of dendritic spikes and increased their amplitude. Triggering an astrocytic mechanism controlling endogenous D-serine supply via endocannabinoid receptors (CBRs) also increased dendritic spiking. Unexpectedly, this pathway was activated by pyramidal cell activity primarily in the theta range, which required HCN channels and astrocytic CB1Rs. Therefore, astrocytes close a positive and frequency-dependent feedback loop between pyramidal cell activity and their integration of dendritic input. Its disruption in mice led to an impairment of spatial memory, which demonstrated its behavioral relevance.
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Functional Intraregional and Interregional Heterogeneity between Myenteric Glial Cells of the Colon and Duodenum in Mice. J Neurosci 2022; 42:8694-8708. [PMID: 36319118 PMCID: PMC9671584 DOI: 10.1523/jneurosci.2379-20.2022] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 09/26/2022] [Accepted: 09/27/2022] [Indexed: 02/24/2023] Open
Abstract
Enteric glia are a unique population of peripheral neuroglia that regulate homeostasis in the enteric nervous system (ENS) and intestinal functions. Despite existing in functionally diverse regions of the gastrointestinal tract, enteric glia have been approached scientifically as a homogeneous group of cells. This assumption is at odds with the functional specializations of gastrointestinal organs and recent data suggesting glial heterogeneity in the brain and ENS. Here, we used calcium imaging in transgenic mice of both sexes expressing genetically encoded calcium sensors in enteric glia and conducted contractility studies to investigate functional diversity among myenteric glia in two functionally distinct intestinal organs: the duodenum and the colon. Our data show that myenteric glia exhibit regionally distinct responses to neuromodulators that require intercellular communication with neurons to differing extents in the duodenum and colon. Glia regulate intestinal contractility in a region-specific and pathway-specific manner, which suggests regionally diverse engagement of enteric glia in local motor patterns through discrete signaling pathways. Further, functional response profiles delineate four unique subpopulations among myenteric glia that are differentially distributed between the colon and duodenum. Our findings support the conclusion that myenteric glia exhibit both intraregional and interregional heterogeneity that contributes to region-specific mechanisms that regulate digestive functions. Glial heterogeneity adds an unexpected layer of complexity in peripheral neurocircuits, and understanding the specific functions of specialized glial subtypes will provide new insight into ENS physiology and pathophysiology.SIGNIFICANCE STATEMENT Enteric glia modulate gastrointestinal functions through intercellular communication with enteric neurons. Whether heterogeneity exists among neuron-glia interactions in the digestive tract is not understood. Here, we show that myenteric glia display regional heterogeneity in their responses to neuromodulators in the duodenum and the colon, which are functionally distinct organs. Glial-mediated control of intestinal motility is region and pathway specific. Four myenteric glial subtypes are present within a given gut region that are differently distributed between gut regions. These data provide functional and regional insights into enteric circuit specificity in the adult enteric nervous system.
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Hirunpattarasilp C, Barkaway A, Davis H, Pfeiffer T, Sethi H, Attwell D. Hyperoxia evokes pericyte-mediated capillary constriction. J Cereb Blood Flow Metab 2022; 42:2032-2047. [PMID: 35786054 PMCID: PMC9580167 DOI: 10.1177/0271678x221111598] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Oxygen supplementation is regularly prescribed to patients to treat or prevent hypoxia. However, excess oxygenation can lead to reduced cerebral blood flow (CBF) in healthy subjects and worsen the neurological outcome of critically ill patients. Most studies on the vascular effects of hyperoxia focus on arteries but there is no research on the effects on cerebral capillary pericytes, which are major regulators of CBF. Here, we used bright-field imaging of cerebral capillaries and modeling of CBF to show that hyperoxia (95% superfused O2) led to an increase in intracellular calcium level in pericytes and a significant capillary constriction, sufficient to cause an estimated 25% decrease in CBF. Although hyperoxia is reported to cause vascular smooth muscle cell contraction via generation of reactive oxygen species (ROS), endothelin-1 and 20-HETE, we found that increased cytosolic and mitochondrial ROS levels and endothelin release were not involved in the pericyte-mediated capillary constriction. However, a 20-HETE synthesis blocker greatly reduced the hyperoxia-evoked capillary constriction. Our findings establish pericytes as regulators of CBF in hyperoxia and 20-HETE synthesis as an oxygen sensor in CBF regulation. The results also provide a mechanism by which clinically administered oxygen can lead to a worse neurological outcome.
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Affiliation(s)
- Chanawee Hirunpattarasilp
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, UK.,Princess Srisavangavadhana College of Medicine, Chulabhorn Royal Academy, Bangkok, Thailand
| | - Anna Barkaway
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, UK.,Princess Srisavangavadhana College of Medicine, Chulabhorn Royal Academy, Bangkok, Thailand
| | - Harvey Davis
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, UK.,Princess Srisavangavadhana College of Medicine, Chulabhorn Royal Academy, Bangkok, Thailand
| | - Thomas Pfeiffer
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, UK
| | - Huma Sethi
- Division of Neurosurgery, UCL Queen Square Institute of Neurology, Queen Square, London, UK
| | - David Attwell
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, UK
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31
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Taghdiri N, King KR. Inferring cell communication using single-cell calcium spatiotemporal dynamics. STAR Protoc 2022; 3:101647. [PMID: 36065295 PMCID: PMC9440483 DOI: 10.1016/j.xpro.2022.101647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
- Nika Taghdiri
- Department of Bioengineering, Jacobs School of Engineering, University of California San Diego, La Jolla, CA, USA.
| | - Kevin R King
- Department of Bioengineering, Jacobs School of Engineering, University of California San Diego, La Jolla, CA, USA; Division of Cardiology and Cardiovascular Institute, Department of Medicine, University of California San Diego, La Jolla, CA, USA.
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32
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Mehari FT, Miller M, Pick R, Bader A, Pekayvaz K, Napoli M, Uhl B, Reichel CA, Sperandio M, Walzog B, Schulz C, Massberg S, Stark K. Intravital calcium imaging in myeloid leukocytes identifies calcium frequency spectra as indicators of functional states. Sci Signal 2022; 15:eabe6909. [PMID: 35881691 DOI: 10.1126/scisignal.abe6909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The assessment of leukocyte activation in vivo is mainly based on surrogate parameters, such as cell shape changes and migration patterns. Consequently, additional parameters are required to dissect the complex spatiotemporal activation of leukocytes during inflammation. Here, we showed that intravital microscopy of myeloid leukocyte Ca2+ signals with Ca2+ reporter mouse strains combined with bioinformatic signal analysis provided a tool to assess their activation in vivo. We demonstrated by two-photon microscopy that tissue-resident macrophages reacted to sterile inflammation in the cremaster muscle with Ca2+ transients in a distinct spatiotemporal pattern. Moreover, through high-resolution, intravital spinning disk confocal microscopy, we identified the intracellular Ca2+ signaling patterns of neutrophils during the migration cascade in vivo. These patterns were modulated by the Ca2+ channel Orai1 and Gαi-coupled GPCRs, whose effects were evident through analysis of the range of frequencies of the Ca2+ signal (frequency spectra), which provided insights into the complex patterns of leukocyte Ca2+ oscillations. Together, these findings establish Ca2+ frequency spectra as an additional dimension to assess leukocyte activation and migration during inflammation in vivo.
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Affiliation(s)
- Fitsumbirhan T Mehari
- Medizinische Klinik und Poliklinik I, University Hospital, LMU Munich, 81377 Munich, Germany.,Walter Brendel Centre of Experimental Medicine, Faculty of Medicine, LMU Munich, 81377 Munich, Germany
| | - Meike Miller
- Medizinische Klinik und Poliklinik I, University Hospital, LMU Munich, 81377 Munich, Germany.,Walter Brendel Centre of Experimental Medicine, Faculty of Medicine, LMU Munich, 81377 Munich, Germany
| | - Robert Pick
- Institute for Cardiovascular Physiology and Pathophysiology, Walter Brendel Centre for Experimental Medicine, Biomedical Center (BMC), LMU Munich, 82152 Planegg, Germany
| | - Almke Bader
- Walter Brendel Centre of Experimental Medicine, Faculty of Medicine, LMU Munich, 81377 Munich, Germany.,Institute for Cardiovascular Physiology and Pathophysiology, Walter Brendel Centre for Experimental Medicine, Biomedical Center (BMC), LMU Munich, 82152 Planegg, Germany
| | - Kami Pekayvaz
- Medizinische Klinik und Poliklinik I, University Hospital, LMU Munich, 81377 Munich, Germany.,Walter Brendel Centre of Experimental Medicine, Faculty of Medicine, LMU Munich, 81377 Munich, Germany.,German Center for Cardiovascular Research (DZHK), partner site Munich Heart Alliance, 80802 Munich, Germany
| | - Matteo Napoli
- Institute for Cardiovascular Physiology and Pathophysiology, Walter Brendel Centre for Experimental Medicine, Biomedical Center (BMC), LMU Munich, 82152 Planegg, Germany
| | - Bernd Uhl
- Walter Brendel Centre of Experimental Medicine, Faculty of Medicine, LMU Munich, 81377 Munich, Germany.,Department of Otorhinolaryngology, University Hospital, LMU Munich, 81377, Munich, Germany
| | - Christoph A Reichel
- Walter Brendel Centre of Experimental Medicine, Faculty of Medicine, LMU Munich, 81377 Munich, Germany.,Department of Otorhinolaryngology, University Hospital, LMU Munich, 81377, Munich, Germany
| | - Markus Sperandio
- Institute for Cardiovascular Physiology and Pathophysiology, Walter Brendel Centre for Experimental Medicine, Biomedical Center (BMC), LMU Munich, 82152 Planegg, Germany
| | - Barbara Walzog
- Walter Brendel Centre of Experimental Medicine, Faculty of Medicine, LMU Munich, 81377 Munich, Germany.,Institute for Cardiovascular Physiology and Pathophysiology, Walter Brendel Centre for Experimental Medicine, Biomedical Center (BMC), LMU Munich, 82152 Planegg, Germany
| | - Christian Schulz
- Medizinische Klinik und Poliklinik I, University Hospital, LMU Munich, 81377 Munich, Germany.,Walter Brendel Centre of Experimental Medicine, Faculty of Medicine, LMU Munich, 81377 Munich, Germany.,German Center for Cardiovascular Research (DZHK), partner site Munich Heart Alliance, 80802 Munich, Germany
| | - Steffen Massberg
- Medizinische Klinik und Poliklinik I, University Hospital, LMU Munich, 81377 Munich, Germany.,Walter Brendel Centre of Experimental Medicine, Faculty of Medicine, LMU Munich, 81377 Munich, Germany.,German Center for Cardiovascular Research (DZHK), partner site Munich Heart Alliance, 80802 Munich, Germany
| | - Konstantin Stark
- Medizinische Klinik und Poliklinik I, University Hospital, LMU Munich, 81377 Munich, Germany.,Walter Brendel Centre of Experimental Medicine, Faculty of Medicine, LMU Munich, 81377 Munich, Germany.,German Center for Cardiovascular Research (DZHK), partner site Munich Heart Alliance, 80802 Munich, Germany
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Yang Z, Gong M, Jian T, Li J, Yang C, Ma Q, Deng P, Wang Y, Huang M, Wang H, Yang S, Chen X, Yu Z, Wang M, Chen C, Zhang K. Engrafted glial progenitor cells yield long-term integration and sensory improvement in aged mice. Stem Cell Res Ther 2022; 13:285. [PMID: 35765112 PMCID: PMC9241208 DOI: 10.1186/s13287-022-02959-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 06/05/2022] [Indexed: 12/31/2022] Open
Abstract
Aging causes astrocyte morphological degeneration and functional deficiency, which impairs neuronal functions. Until now, whether age-induced neuronal deficiency could be alleviated by engraftment of glial progenitor cell (GPC) derived astrocytes remained unknown. In the current study, GPCs were generated from embryonic cortical neural stem cells in vitro and transplanted into the brains of aged mice. Their integration and intervention effects in the aged brain were examined 12 months after transplantation. Results indicated that these in-vitro-generated GPC-derived astrocytes possessed normal functional properties. After transplantation they could migrate, differentiate, achieve long-term integration, and maintain much younger morphology in the aged brain. Additionally, these GPC-derived astrocytes established endfeet expressing aquaporin-4 (AQP4) and ameliorate AQP4 polarization in the aged neocortex. More importantly, age-dependent sensory response degeneration was reversed by GPC transplantation. This work demonstrates that rejuvenation of the astrocyte niche is a promising treatment to prevent age-induced degradation of neuronal and behavioral functions.
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Affiliation(s)
- Zhiqi Yang
- Department of Neurology, Lanzhou University Second Hospital, Cuiyingmen 82, Chengguan District, Lanzhou, 730030, Gansu, China.,Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, 400038, China
| | - Mingyue Gong
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, 400038, China
| | - Tingliang Jian
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, 400038, China
| | - Jin Li
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, 400038, China
| | - Chuanyan Yang
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, 400038, China
| | - Qinlong Ma
- Department of Occupational Health, Third Military Medical University, Chongqing, 400038, China
| | - Ping Deng
- Department of Occupational Health, Third Military Medical University, Chongqing, 400038, China
| | - Yuxia Wang
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, 400038, China
| | - Mingzhu Huang
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, 400038, China
| | - Haoyu Wang
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, 400038, China
| | - Shaofan Yang
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, 400038, China
| | - Xiaowei Chen
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, 400038, China
| | - Zhengping Yu
- Department of Occupational Health, Third Military Medical University, Chongqing, 400038, China
| | - Manxia Wang
- Department of Neurology, Lanzhou University Second Hospital, Cuiyingmen 82, Chengguan District, Lanzhou, 730030, Gansu, China.
| | - Chunhai Chen
- Department of Occupational Health, Third Military Medical University, Chongqing, 400038, China.
| | - Kuan Zhang
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, 400038, China.
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34
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K v1.1 preserves the neural stem cell pool and facilitates neuron maturation during adult hippocampal neurogenesis. Proc Natl Acad Sci U S A 2022; 119:e2118240119. [PMID: 35613055 PMCID: PMC9295736 DOI: 10.1073/pnas.2118240119] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Despite decades of research on adult neurogenesis, little is known about the role of bioelectric signaling in this process. In this study, we describe how a voltage-gated potassium channel, Kv1.1, supports adult neurogenesis by maintaining the neural stem cell niche and facilitating newborn neuron development. Additionally, we show that deletion of Kv1.1 from adult neural stem cells contributes to modest impairments in hippocampus-dependent contextual fear learning and memory. Dysfunctional adult neurogenesis has been implicated in cognitive decline associated with aging and neurological disease. Therefore, understanding the role of Kv1.1 in adult neurogenesis represents an opportunity to identify new therapeutic targets to promote healthy neurogenesis and cognition. Adult hippocampal neurogenesis is critical for learning and memory, and aberrant adult neurogenesis has been implicated in cognitive decline associated with aging and neurological diseases [J. T. Gonçalves, S. T. Schafer, F. H. Gage, Cell 167, 897–914 (2016)]. In previous studies, we observed that the delayed-rectifier voltage-gated potassium channel Kv1.1 controls the membrane potential of neural stem and progenitor cells and acts as a brake on neurogenesis during neonatal hippocampal development [S. M. Chou et al., eLife 10, e58779 (2021)]. To assess the role of Kv1.1 in adult hippocampal neurogenesis, we developed an inducible conditional knockout mouse to specifically remove Kv1.1 from adult neural stem cells via tamoxifen administration. We determined that Kv1.1 deletion in adult neural stem cells causes overproliferation and depletion of radial glia-like neural stem cells, prevents proper adult-born granule cell maturation and integration into the dentate gyrus, and moderately impairs hippocampus-dependent contextual fear learning and memory. Taken together, these findings support a critical role for this voltage-gated ion channel in adult neurogenesis.
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35
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Császár E, Lénárt N, Cserép C, Környei Z, Fekete R, Pósfai B, Balázsfi D, Hangya B, Schwarcz AD, Szabadits E, Szöllősi D, Szigeti K, Máthé D, West BL, Sviatkó K, Brás AR, Mariani JC, Kliewer A, Lenkei Z, Hricisák L, Benyó Z, Baranyi M, Sperlágh B, Menyhárt Á, Farkas E, Dénes Á. Microglia modulate blood flow, neurovascular coupling, and hypoperfusion via purinergic actions. J Exp Med 2022; 219:e20211071. [PMID: 35201268 PMCID: PMC8932534 DOI: 10.1084/jem.20211071] [Citation(s) in RCA: 129] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 10/28/2021] [Accepted: 01/03/2022] [Indexed: 12/13/2022] Open
Abstract
Microglia, the main immunocompetent cells of the brain, regulate neuronal function, but their contribution to cerebral blood flow (CBF) regulation has remained elusive. Here, we identify microglia as important modulators of CBF both under physiological conditions and during hypoperfusion. Microglia establish direct, dynamic purinergic contacts with cells in the neurovascular unit that shape CBF in both mice and humans. Surprisingly, the absence of microglia or blockade of microglial P2Y12 receptor (P2Y12R) substantially impairs neurovascular coupling in mice, which is reiterated by chemogenetically induced microglial dysfunction associated with impaired ATP sensitivity. Hypercapnia induces rapid microglial calcium changes, P2Y12R-mediated formation of perivascular phylopodia, and microglial adenosine production, while depletion of microglia reduces brain pH and impairs hypercapnia-induced vasodilation. Microglial actions modulate vascular cyclic GMP levels but are partially independent of nitric oxide. Finally, microglial dysfunction markedly impairs P2Y12R-mediated cerebrovascular adaptation to common carotid artery occlusion resulting in hypoperfusion. Thus, our data reveal a previously unrecognized role for microglia in CBF regulation, with broad implications for common neurological diseases.
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Affiliation(s)
- Eszter Császár
- “Momentum” Laboratory of Neuroimmunology, Institute of Experimental Medicine, Budapest, Hungary
- János Szentágothai Doctoral School of Neurosciences, Schools of PhD Studies, Semmelweis University, Budapest, Hungary
| | - Nikolett Lénárt
- “Momentum” Laboratory of Neuroimmunology, Institute of Experimental Medicine, Budapest, Hungary
| | - Csaba Cserép
- “Momentum” Laboratory of Neuroimmunology, Institute of Experimental Medicine, Budapest, Hungary
| | - Zsuzsanna Környei
- “Momentum” Laboratory of Neuroimmunology, Institute of Experimental Medicine, Budapest, Hungary
| | - Rebeka Fekete
- “Momentum” Laboratory of Neuroimmunology, Institute of Experimental Medicine, Budapest, Hungary
| | - Balázs Pósfai
- “Momentum” Laboratory of Neuroimmunology, Institute of Experimental Medicine, Budapest, Hungary
- János Szentágothai Doctoral School of Neurosciences, Schools of PhD Studies, Semmelweis University, Budapest, Hungary
| | - Diána Balázsfi
- Lendület Laboratory of Systems Neuroscience, Institute of Experimental Medicine, Budapest, Hungary
| | - Balázs Hangya
- Lendület Laboratory of Systems Neuroscience, Institute of Experimental Medicine, Budapest, Hungary
| | - Anett D. Schwarcz
- “Momentum” Laboratory of Neuroimmunology, Institute of Experimental Medicine, Budapest, Hungary
| | - Eszter Szabadits
- “Momentum” Laboratory of Neuroimmunology, Institute of Experimental Medicine, Budapest, Hungary
| | - Dávid Szöllősi
- Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
| | - Krisztián Szigeti
- Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
| | - Domokos Máthé
- Hungarian Centre of Excellence for Molecular Medicine, Szeged, Hungary
| | | | - Katalin Sviatkó
- Lendület Laboratory of Systems Neuroscience, Institute of Experimental Medicine, Budapest, Hungary
| | - Ana Rita Brás
- “Momentum” Laboratory of Neuroimmunology, Institute of Experimental Medicine, Budapest, Hungary
- János Szentágothai Doctoral School of Neurosciences, Schools of PhD Studies, Semmelweis University, Budapest, Hungary
| | - Jean-Charles Mariani
- Institute of Psychiatry and Neurosciences of Paris, INSERM U1266, Université de Paris, Paris, France
| | - Andrea Kliewer
- Institute of Psychiatry and Neurosciences of Paris, INSERM U1266, Université de Paris, Paris, France
| | - Zsolt Lenkei
- Institute of Psychiatry and Neurosciences of Paris, INSERM U1266, Université de Paris, Paris, France
| | - László Hricisák
- Institute of Translational Medicine, Semmelweis University, Budapest, Hungary
| | - Zoltán Benyó
- Institute of Translational Medicine, Semmelweis University, Budapest, Hungary
| | - Mária Baranyi
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, Budapest, Hungary
| | - Beáta Sperlágh
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, Budapest, Hungary
| | - Ákos Menyhárt
- Hungarian Centre of Excellence for Molecular Medicine, University of Szeged, Cerebral Blood Flow and Metabolism Research Group, Szeged, Hungary
- Department of Medical Physics and Informatics, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
| | - Eszter Farkas
- Hungarian Centre of Excellence for Molecular Medicine, University of Szeged, Cerebral Blood Flow and Metabolism Research Group, Szeged, Hungary
- Department of Cell Biology and Molecular Medicine, Albert Szent-Györgyi Medical School, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Ádám Dénes
- “Momentum” Laboratory of Neuroimmunology, Institute of Experimental Medicine, Budapest, Hungary
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36
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Márta K, Booth D, Csordás G, Hajnóczky G. Fluorescent protein transgenic mice for the study of Ca 2+ and redox signaling. Free Radic Biol Med 2022; 181:241-250. [PMID: 35158029 PMCID: PMC8988923 DOI: 10.1016/j.freeradbiomed.2022.02.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 02/10/2022] [Indexed: 01/29/2023]
Abstract
Many unanswered questions of physiology and medicine require in vivo studies of cellular processes in murine models. These processes commonly depend on intracellular Ca2+ and redox alterations. Fluorescent dyes have succeeded in real-time intracellular monitoring of Ca2+, redox and the different Reactive Oxygen Species (ROS) in single cells, but have seldomly been applied in vivo. The advance in Fluorescent Protein (FP) technology has created alternative tools for the same task, which can be delivered with viruses or genomic integration strategies into mice. With the availability of several color options for both Ca2+ and redox reporting FP, multiparameter measurements have also become feasible: measuring different species, and the same parameter at different locations using organelle-specific targeting sequences at the same time. We, here, focus on mice with genomic integration of Ca2+ and redox reporters, provide a list of the available models and summarize the strategies of their generation and utilization. We also describe a novel Calcium DoubleSpy mouse model that conditionally expresses both RCaMP in the cytoplasm and GEM-GECO1 in the mitochondrial matrix, allowing the study of mitochondrial Ca2+ related physiology and pathogenesis simultaneously in two distinct intracellular compartments.
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Affiliation(s)
- Katalin Márta
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - David Booth
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - György Csordás
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - György Hajnóczky
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, 19107, USA.
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37
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Genetically encoded photo-switchable molecular sensors for optoacoustic and super-resolution imaging. Nat Biotechnol 2022; 40:598-605. [PMID: 34845372 PMCID: PMC9005348 DOI: 10.1038/s41587-021-01100-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 09/17/2021] [Indexed: 02/07/2023]
Abstract
Reversibly photo-switchable proteins are essential for many super-resolution fluorescence microscopic and optoacoustic imaging methods. However, they have yet to be used as sensors that measure the distribution of specific analytes at the nanoscale or in the tissues of live animals. Here we constructed the prototype of a photo-switchable Ca2+ sensor based on GCaMP5G that can be switched with 405/488-nm light and describe its molecular mechanisms at the structural level, including the importance of the interaction of the core barrel structure of the fluorescent protein with the Ca2+ receptor moiety. We demonstrate super-resolution imaging of Ca2+ concentration in cultured cells and optoacoustic Ca2+ imaging in implanted tumor cells in mice under controlled Ca2+ conditions. Finally, we show the generalizability of the concept by constructing examples of photo-switching maltose and dopamine sensors based on periplasmatic binding protein and G-protein-coupled receptor-based sensors.
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38
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Logiacco F, Xia P, Georgiev SV, Franconi C, Chang YJ, Ugursu B, Sporbert A, Kühn R, Kettenmann H, Semtner M. Microglia sense neuronal activity via GABA in the early postnatal hippocampus. Cell Rep 2021; 37:110128. [PMID: 34965412 DOI: 10.1016/j.celrep.2021.110128] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 09/14/2021] [Accepted: 11/22/2021] [Indexed: 01/05/2023] Open
Abstract
Microglia, the resident macrophages in the central nervous system, express receptors for classical neurotransmitters, such as γ-aminobutyric acid (GABA) and glutamate, suggesting that they sense synaptic activity. To detect microglial Ca2+ responses to neuronal activity, we generate transgenic mouse lines expressing the fluorescent Ca2+ indicator GCaMP6m, specifically in microglia and demonstrate that electrical stimulation of the Schaffer collateral pathway results in microglial Ca2+ responses in early postnatal but not adult hippocampus. Preceding the microglial responses, we also observe similar Ca2+ responses in astrocytes, and both are sensitive to tetrodotoxin. Blocking astrocytic glutamate uptake or GABA transport abolishes stimulation-induced microglial responses as well as antagonizing the microglial GABAB receptor. Our data, therefore, suggest that the neuronal activity-induced glutamate uptake and the release of GABA by astrocytes trigger the activation of GABAB receptors in microglia. This neuron, astrocyte, and microglia communication pathway might modulate microglial activity in developing neuronal networks.
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Affiliation(s)
- Francesca Logiacco
- Cellular Neurosciences, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany; Department of Biology, Chemistry, and Pharmacy, Freie Universität Berlin, 12169 Berlin, Germany
| | - Pengfei Xia
- Cellular Neurosciences, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
| | - Svilen Veselinov Georgiev
- Cellular Neurosciences, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
| | - Celeste Franconi
- Cellular Neurosciences, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
| | - Yi-Jen Chang
- Cellular Neurosciences, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
| | - Bilge Ugursu
- Cellular Neurosciences, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany; Experimental Ophthalmology, Charité Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Anje Sporbert
- Advanced Light Microscopy, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
| | - Ralf Kühn
- Transgenic Core Facility, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
| | - Helmut Kettenmann
- Cellular Neurosciences, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany; Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Marcus Semtner
- Cellular Neurosciences, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany.
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GYARMATI GEORGINA, TOMA ILDIKÓ, IZUHARA AUDREY, BURFORD JAMESL, SHROFF URVINIKHIL, PAPADOURI STELLA, DEEPAK SACHIN, PETI-PETERDI JÁNOS. The role of TRPC6 calcium channels and P2 purinergic receptors in podocyte mechanical and metabolic sensing. Physiol Int 2021; 109:2021.00205. [PMID: 34978536 PMCID: PMC9200898 DOI: 10.1556/2060.2021.00205] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 11/22/2021] [Indexed: 12/17/2022]
Abstract
Podocyte calcium (Ca2+) signaling plays important roles in the (patho)physiology of the glomerular filtration barrier. Overactivation of podocyte transient receptor potential canonical (TRPC) channels including TRPC6 and purinergic signaling via P2 receptors that are known mechanosensors can increase podocyte intracellular Ca2+ levels ([Ca2+]i) and cause cell injury, proteinuria and glomerular disease including in diabetes. However, important mechanistic details of the trigger and activation of these pathways in vivo in the intact glomerular environment are lacking. Here we show direct visual evidence that podocytes can sense mechanical overload (increased glomerular capillary pressure) and metabolic alterations (increased plasma glucose) via TRPC6 and purinergic receptors including P2Y2. Multiphoton microscopy of podocyte [Ca2+]i was performed in vivo using wild-type and TRPC6 or P2Y2 knockout (KO) mice expressing the calcium reporter GCaMP3/5 only in podocytes and in vitro using freshly dissected microperfused glomeruli. Single-nephron intra-glomerular capillary pressure elevations induced by obstructing the efferent arteriole lumen with laser-induced microthrombus in vivo and by a micropipette in vitro triggered >2-fold increases in podocyte [Ca2+]i. These responses were blocked in TRPC6 and P2Y2 KO mice. Acute elevations of plasma glucose caused >4-fold increases in podocyte [Ca2+]i that were abolished by pharmacological inhibition of TRPC6 or P2 receptors using SAR7334 or suramin treatment, respectively. This study established the role of Ca2+ signaling via TRPC6 channels and P2 receptors in mechanical and metabolic sensing of podocytes in vivo, which are promising therapeutic targets in conditions with high intra-glomerular capillary pressure and plasma glucose, such as diabetic and hypertensive nephropathy.
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Affiliation(s)
- GEORGINA GYARMATI
- Departments of Physiology and Neuroscience, and Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA 90033, USA
| | - ILDIKÓ TOMA
- Departments of Physiology and Neuroscience, and Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA 90033, USA
| | - AUDREY IZUHARA
- Departments of Physiology and Neuroscience, and Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA 90033, USA
| | - JAMES L. BURFORD
- Departments of Physiology and Neuroscience, and Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA 90033, USA
| | - URVI NIKHIL SHROFF
- Departments of Physiology and Neuroscience, and Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA 90033, USA
| | - STELLA PAPADOURI
- Departments of Physiology and Neuroscience, and Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA 90033, USA
| | - SACHIN DEEPAK
- Departments of Physiology and Neuroscience, and Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA 90033, USA
| | - JÁNOS PETI-PETERDI
- Departments of Physiology and Neuroscience, and Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA 90033, USA
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Synapse development is regulated by microglial THIK-1 K + channels. Proc Natl Acad Sci U S A 2021; 118:2106294118. [PMID: 34642249 PMCID: PMC8545484 DOI: 10.1073/pnas.2106294118] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/08/2021] [Indexed: 12/17/2022] Open
Abstract
Microglia are the brain’s resident immune cells, surveying the brain with motile processes, which can remove pathogens but also prune unnecessary junctions between the neurons (synapses). A potassium channel, THIK-1, in the microglial membrane allows efflux of potassium from these cells and thereby regulates their membrane voltage as well as their process motility and release of inflammatory mediators. Here, using THIK-1–blocking drugs and THIK-1–deficient mice, we demonstrate that THIK-1 controls removal of synaptic material by microglia, which reduces the number of functional synapses in the developing brain.
Microglia are the resident immune cells of the central nervous system. They constantly survey the brain parenchyma for redundant synapses, debris, or dying cells, which they remove through phagocytosis. Microglial ramification, motility, and cytokine release are regulated by tonically active THIK-1 K+ channels on the microglial plasma membrane. Here, we examined whether these channels also play a role in phagocytosis. Using pharmacological blockers and THIK-1 knockout (KO) mice, we found that a lack of THIK-1 activity approximately halved both microglial phagocytosis and marker levels for the lysosomes that degrade phagocytically removed material. These changes may reflect a decrease of intracellular [Ca2+]i activity, which was observed when THIK-1 activity was reduced, since buffering [Ca2+]i reduced phagocytosis. Less phagocytosis is expected to result in impaired pruning of synapses. In the hippocampus, mice lacking THIK-1 expression had an increased number of anatomically and electrophysiologically defined glutamatergic synapses during development. This resulted from an increased number of presynaptic terminals, caused by impaired removal by THIK-1 KO microglia. The dependence of synapse number on THIK-1 K+ channels, which control microglial surveillance and phagocytic ability, implies that changes in the THIK-1 expression level in disease states may contribute to altering neural circuit function.
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Herrero MJ, Wang L, Hernandez-Pineda D, Banerjee P, Matos HY, Goodrich M, Panigrahi A, Smith NA, Corbin JG. Sex-Specific Social Behavior and Amygdala Proteomic Deficits in Foxp2 +/- Mutant Mice. Front Behav Neurosci 2021; 15:706079. [PMID: 34421555 PMCID: PMC8374433 DOI: 10.3389/fnbeh.2021.706079] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 06/29/2021] [Indexed: 12/20/2022] Open
Abstract
In humans, mutations in the transcription factor encoding gene, FOXP2, are associated with language and Autism Spectrum Disorders (ASD), the latter characterized by deficits in social interactions. However, little is known regarding the function of Foxp2 in male or female social behavior. Our previous studies in mice revealed high expression of Foxp2 within the medial subnucleus of the amygdala (MeA), a limbic brain region highly implicated in innate social behaviors such as mating, aggression, and parental care. Here, using a comprehensive panel of behavioral tests in male and female Foxp2 +/- heterozygous mice, we investigated the role Foxp2 plays in MeA-linked innate social behaviors. We reveal significant deficits in olfactory processing, social interaction, mating, aggressive, and parental behaviors. Interestingly, some of these deficits are displayed in a sex-specific manner. To examine the consequences of Foxp2 loss of function specifically in the MeA, we conducted a proteomic analysis of microdissected MeA tissue. This analyses revealed putative sex differences expression of a host of proteins implicated in neuronal communication, connectivity, and dopamine signaling. Consistent with this, we discovered that MeA Foxp2-lineage cells were responsive to dopamine with differences between males and females. Thus, our findings reveal a central and sex-specific role for Foxp2 in social behavior and MeA function.
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Affiliation(s)
- Maria Jesus Herrero
- Center for Neuroscience Research, Children’s National Hospital, Washington, DC, United States
| | - Li Wang
- Center for Neuroscience Research, Children’s National Hospital, Washington, DC, United States
| | - David Hernandez-Pineda
- Center for Neuroscience Research, Children’s National Hospital, Washington, DC, United States
| | - Payal Banerjee
- Center for Genomic Medicine, Children’s National Hospital, Washington, DC, United States
| | - Heidi Y. Matos
- Center for Neuroscience Research, Children’s National Hospital, Washington, DC, United States
| | - Meredith Goodrich
- Center for Neuroscience Research, Children’s National Hospital, Washington, DC, United States
| | - Aswini Panigrahi
- Center for Cancer and Immunology Research, Children’s National Hospital, Washington, DC, United States
| | - Nathan Anthony Smith
- Center for Neuroscience Research, Children’s National Hospital, Washington, DC, United States
| | - Joshua G. Corbin
- Center for Neuroscience Research, Children’s National Hospital, Washington, DC, United States
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Mojtahedi N, Kovalchuk Y, Böttcher A, Garaschuk O. Stable behavioral state-specific large scale activity patterns in the developing cortex of neonates. Cell Calcium 2021; 98:102448. [PMID: 34375923 DOI: 10.1016/j.ceca.2021.102448] [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: 05/20/2021] [Revised: 07/14/2021] [Accepted: 07/20/2021] [Indexed: 01/31/2023]
Abstract
Intrinsic neuronal activity is a hallmark of the developing brain. In rodents, a handful of such activities were described in different cortical areas but the unifying macroscopic perspective is still lacking. Here we combined large-scale in vivo Ca2+ imaging of the dorsal cortex in non-anesthetized neonatal mice with mathematical analyses to reveal unique behavioral state-specific maps of intrinsic activity. These maps were remarkably stable over time within and across experiments and used patches of correlated activity with little hemispheric symmetry as well as stationary and propagating waves as building blocks. Importantly, the maps recorded during motion and rest were almost inverse, with frontoparietal areas active during motion and posterior-lateral areas active at rest. The retrosplenial cortex engaged in both resting- and motion-related activities via functional long-range connections with respective cortical areas. The data obtained bind different region-specific activity patterns described so far into a single consistent picture and set the stage for future inactivation studies, probing the exact function of this complex activity pattern for cortical wiring in neonates.
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Affiliation(s)
- Nima Mojtahedi
- Institute of Physiology, Department of Neurophysiology, Eberhard Karls University of Tübingen, 72074 Tübingen, Germany
| | - Yury Kovalchuk
- Institute of Physiology, Department of Neurophysiology, Eberhard Karls University of Tübingen, 72074 Tübingen, Germany
| | - Alexander Böttcher
- Werner Reichardt Centre for Integrative Neuroscience, University of Tübingen, 72076 Tübingen, Germany
| | - Olga Garaschuk
- Institute of Physiology, Department of Neurophysiology, Eberhard Karls University of Tübingen, 72074 Tübingen, Germany.
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Johnson KO, Smith NA, Goldstein EZ, Gallo V, Triplett JW. NMDA Receptor Expression by Retinal Ganglion Cells Is Not Required for Retinofugal Map Formation nor Eye-Specific Segregation in the Mouse. eNeuro 2021; 8:ENEURO.0115-20.2021. [PMID: 34193509 PMCID: PMC8287875 DOI: 10.1523/eneuro.0115-20.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 05/19/2021] [Accepted: 05/21/2021] [Indexed: 12/01/2022] Open
Abstract
Retinal ganglion cells (RGCs) project topographically to the superior colliculus (SC) and dorsal lateral geniculate nucleus (dLGN). Spontaneous activity plays a critical role in retinotopic mapping in both regions; however, the molecular mechanisms underlying activity-dependent refinement remain unclear. Previous pharmacologic studies implicate NMDA receptors (NMDARs) in the establishment of retinotopy. In other brain regions, NMDARs are expressed on both the presynaptic and postsynaptic side of the synapse, and recent work suggests that presynaptic and postsynaptic NMDARs play distinct roles in retinotectal developmental dynamics. To directly test the role of NMDARs expressed by RGCs in retinofugal map formation, we took a conditional genetic knock-out approach to delete the obligate GluN1 subunit of NMDARs in RGCs. Here, we demonstrate reduced GluN1 expression in the retina of Chrnb3-Cre;GluN1flox/flox (pre-cKO) mice without altered expression in the SC. Anatomical tracing experiments revealed no significant changes in termination zone size in the SC and dLGN of pre-cKO mice, suggesting NMDAR function in RGCs is not an absolute requirement for topographic refinement. Further, we observed no change in the eye-specific organization of retinal inputs to the SC nor dLGN. To verify that NMDA induces activity in RGC terminals, we restricted GCaMP5 expression to RGCs and confirmed induction of calcium transients in RGC terminals. Together, these findings demonstrate that NMDARs expressed by RGCs are not required for retinofugal topographic map formation nor eye-specific segregation in the mouse.
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Affiliation(s)
- Kristy O Johnson
- Center for Neuroscience Research, Children's National Research Institute, Washington, DC 20010
- Institute for Biomedical Sciences, The George Washington University School of Medicine and Health Sciences, Washington, DC 20052
| | - Nathan A Smith
- Center for Neuroscience Research, Children's National Research Institute, Washington, DC 20010
- Department of Pediatrics, The George Washington University School of Medicine and Health Sciences, Washington, DC 20052
- Department of Pharmacology and Physiology, The George Washington University School of Medicine and Health Sciences, Washington, DC 20052
| | - Evan Z Goldstein
- Center for Neuroscience Research, Children's National Research Institute, Washington, DC 20010
| | - Vittorio Gallo
- Center for Neuroscience Research, Children's National Research Institute, Washington, DC 20010
- Institute for Biomedical Sciences, The George Washington University School of Medicine and Health Sciences, Washington, DC 20052
- Department of Pediatrics, The George Washington University School of Medicine and Health Sciences, Washington, DC 20052
- Department of Pharmacology and Physiology, The George Washington University School of Medicine and Health Sciences, Washington, DC 20052
| | - Jason W Triplett
- Center for Neuroscience Research, Children's National Research Institute, Washington, DC 20010
- Institute for Biomedical Sciences, The George Washington University School of Medicine and Health Sciences, Washington, DC 20052
- Department of Pediatrics, The George Washington University School of Medicine and Health Sciences, Washington, DC 20052
- Department of Pharmacology and Physiology, The George Washington University School of Medicine and Health Sciences, Washington, DC 20052
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Redmon SN, Yarishkin O, Lakk M, Jo A, Mustafic E, Tvrdik P, Križaj D. TRPV4 channels mediate the mechanoresponse in retinal microglia. Glia 2021; 69:1563-1582. [PMID: 33624376 PMCID: PMC8989051 DOI: 10.1002/glia.23979] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 02/02/2021] [Accepted: 02/02/2021] [Indexed: 12/12/2022]
Abstract
The physiological and neurological correlates of plummeting brain osmolality during edema, traumatic CNS injury, and severe ischemia are compounded by neuroinflammation. Using multiple approaches, we investigated how retinal microglia respond to challenges mediated by increases in strain, osmotic gradients, and agonists of the stretch-activated cation channel TRPV4. Dissociated and intact microglia were TRPV4-immunoreactive and responded to the selective agonist GSK1016790A and substrate stretch with altered motility and elevations in intracellular calcium ([Ca2+ ]i ). Agonist- and hypotonicity-induced swelling was associated with a nonselective outwardly rectifying cation current, increased [Ca2+ ]i , and retraction of higher-order processes. The antagonist HC067047 reduced the extent of hypotonicity-induced microglial swelling and inhibited the suppressive effects of GSK1016790A and hypotonicity on microglial branching. Microglial TRPV4 signaling required intermediary activation of phospholipase A2 (PLA2), cytochrome P450, and epoxyeicosatrienoic acid production (EETs). The expression pattern of vanilloid thermoTrp genes in retinal microglia was markedly different from retinal neurons, astrocytes, and cortical microglia. These results suggest that TRPV4 represents a primary retinal microglial sensor of osmochallenges under physiological and pathological conditions. Its activation, associated with PLA2, modulates calcium signaling and cell architecture. TRPV4 inhibition might be a useful strategy to suppress microglial overactivation in the swollen and edematous CNS.
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Affiliation(s)
- Sarah N. Redmon
- Department of Ophthalmology & Visual Sciences, Moran Eye Institute, Salt Lake City, UT 84132
| | - Oleg Yarishkin
- Department of Ophthalmology & Visual Sciences, Moran Eye Institute, Salt Lake City, UT 84132
| | - Monika Lakk
- Department of Ophthalmology & Visual Sciences, Moran Eye Institute, Salt Lake City, UT 84132
| | - Andrew Jo
- Department of Ophthalmology & Visual Sciences, Moran Eye Institute, Salt Lake City, UT 84132
| | - Edin Mustafic
- Department of Ophthalmology & Visual Sciences, Moran Eye Institute, Salt Lake City, UT 84132
| | - Peter Tvrdik
- Department of Neurological Surgery, University of Virginia School of Medicine, Charlottesville VA 22908
| | - David Križaj
- Department of Ophthalmology & Visual Sciences, Moran Eye Institute, Salt Lake City, UT 84132
- Interdepartmental Program in Neuroscience, University of Utah, Salt Lake City, UT 84132
- Department of Bioengineering, University of Utah, Salt Lake City, UT 84132
- Department of Neurobiology & Anatomy, University of Utah, Salt Lake City, UT 84132
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Loss of KCNQ2 or KCNQ3 Leads to Multifocal Time-Varying Activity in the Neonatal Forebrain Ex Vivo. eNeuro 2021; 8:ENEURO.0024-21.2021. [PMID: 33863780 PMCID: PMC8143017 DOI: 10.1523/eneuro.0024-21.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 04/05/2021] [Accepted: 04/08/2021] [Indexed: 12/29/2022] Open
Abstract
Epileptic encephalopathies represent a group of disorders often characterized by refractory seizures, regression in cognitive development, and typically poor prognosis. Dysfunction of KCNQ2 and KCNQ3 channels has emerged as a major cause of neonatal epilepsy. However, our understanding of the cellular mechanisms that may both explain the origins of epilepsy and inform treatment strategies for KCNQ2 and KCNQ3 dysfunction is still lacking. Here, using mesoscale calcium imaging and pharmacology, we demonstrate that in mouse neonatal brain slices, conditional loss of Kcnq2 from forebrain excitatory neurons (Pyr:Kcnq2 mice) or constitutive deletion of Kcnq3 leads to sprawling hyperactivity across the neocortex. Surprisingly, the generation of time-varying hypersynchrony in slices from Pyr:Kcnq2 mice does not require fast synaptic transmission. This is in contrast to control littermates and constitutive Kcnq3 knock-out mice where activity is primarily driven by fast synaptic transmission in the neocortex. Unlike in the neocortex, hypersynchronous activity in the hippocampal formation from Kcnq2 conditional and Kcnq3 constitutive knock-out mice persists in the presence of synaptic transmission blockers. Thus, we propose that loss of KCNQ2 or KCNQ3 function differentially leads to network hyperactivity across the forebrain in a region-specific and macro-circuit-specific manner.
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Chen YL, Baker TM, Lee F, Shui B, Lee JC, Tvrdik P, Kotlikoff MI, Sonkusare SK. Calcium Signal Profiles in Vascular Endothelium from Cdh5-GCaMP8 and Cx40-GCaMP2 Mice. J Vasc Res 2021; 58:159-171. [PMID: 33706307 PMCID: PMC8102377 DOI: 10.1159/000514210] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 12/23/2020] [Indexed: 01/04/2023] Open
Abstract
INTRODUCTION Studies in Cx40-GCaMP2 mice, which express calcium biosensor GCaMP2 in the endothelium under connexin 40 promoter, have identified the unique properties of endothelial calcium signals. However, Cx40-GCaMP2 mouse is associated with a narrow dynamic range and lack of signal in the venous endothelium. Recent studies have proposed many GCaMPs (GCaMP5/6/7/8) with improved properties although their performance in endothelium-specific calcium studies is not known. METHODS We characterized a newly developed mouse line that constitutively expresses GCaMP8 in the endothelium under the VE-cadherin (Cdh5-GCaMP8) promoter. Calcium signals through endothelial IP3 receptors and TRP vanilloid 4 (TRPV4) ion channels were recorded in mesenteric arteries (MAs) and veins from Cdh5-GCaMP8 and Cx40-GCaMP2 mice. RESULTS Cdh5-GCaMP8 mice showed lower baseline fluorescence intensity, higher dynamic range, and higher amplitudes of individual calcium signals than Cx40-GCaMP2 mice. Importantly, Cdh5-GCaMP8 mice enabled the first recordings of discrete calcium signals in the intact venous endothelium and revealed striking differences in IP3 receptor and TRPV4 channel calcium signals between MAs and mesenteric veins. CONCLUSION Our findings suggest that Cdh5-GCaMP8 mice represent significant improvements in dynamic range, sensitivity for low-intensity signals, and the ability to record calcium signals in venous endothelium.
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Affiliation(s)
- Yen Lin Chen
- Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, Virginia, USA
| | - Thomas M Baker
- Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, Virginia, USA
| | - Frank Lee
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Bo Shui
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Jane C Lee
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Petr Tvrdik
- Departments of Neurosurgery and Neuroscience and Bioengineering, University of Virginia, Charlottesville, Virginia, USA
| | - Michael I Kotlikoff
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Swapnil K Sonkusare
- Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, Virginia, USA,
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA,
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Slc1a3-2A-CreERT2 mice reveal unique features of Bergmann glia and augment a growing collection of Cre drivers and effectors in the 129S4 genetic background. Sci Rep 2021; 11:5412. [PMID: 33686166 PMCID: PMC7940647 DOI: 10.1038/s41598-021-84887-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Accepted: 02/22/2021] [Indexed: 12/26/2022] Open
Abstract
Genetic variation is a primary determinant of phenotypic diversity. In laboratory mice, genetic variation can be a serious experimental confounder, and thus minimized through inbreeding. However, generalizations of results obtained with inbred strains must be made with caution, especially when working with complex phenotypes and disease models. Here we compared behavioral characteristics of C57Bl/6—the strain most widely used in biomedical research—with those of 129S4. In contrast to 129S4, C57Bl/6 demonstrated high within-strain and intra-litter behavioral hyperactivity. Although high consistency would be advantageous, the majority of disease models and transgenic tools are in C57Bl/6. We recently established six Cre driver lines and two Cre effector lines in 129S4. To augment this collection, we genetically engineered a Cre line to study astrocytes in 129S4. It was validated with two Cre effector lines: calcium indicator gCaMP5g-tdTomato and RiboTag—a tool widely used to study cell type-specific translatomes. These reporters are in different genomic loci, and in both the Cre was functional and astrocyte-specific. We found that calcium signals lasted longer and had a higher amplitude in cortical compared to hippocampal astrocytes, genes linked to a single neurodegenerative disease have highly divergent expression patterns, and that ribosome proteins are non-uniformly expressed across brain regions and cell types.
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Liu C, Han Y, Zhao X, Li B, Xu L, Li D, Li G. POLR2A blocks osteoclastic bone resorption and protects against osteoporosis by interacting with CREB1. J Cell Physiol 2021; 236:5134-5146. [PMID: 33595106 DOI: 10.1002/jcp.30220] [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] [Received: 05/26/2020] [Revised: 12/01/2020] [Accepted: 12/03/2020] [Indexed: 11/10/2022]
Abstract
Bone-resorbing osteoclasts significantly contribute to osteoporosis, and understanding the mechanisms of osteoclastogenesis is crucial for developing new drugs to treat diseases associated with bone loss. Here, we report that POLR2A is upregulated during osteoclastogenesis. Functional analyses showed that the inhibition of POLR2A decreased osteoclastogenesis, whereas the overexpression of POLR2A had completely opposite effects in vitro. Notably, the osteoclast-specific deletion of POLR2A blocks bone resorption in vivo. Furthermore, POLR2A loss-of-function suppresses estrogen deficiency-induced bone resorption. Mechanistically, POLR2A regulates the assembly of CREB1 on the regulatory elements of its target genes. Collectively, using genetic, pharmacological, and disease mouse models, we have identified a previously undescribed protein that interacts with CREB1 to regulate osteoclastic bone resorption.
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Affiliation(s)
- Chuxiao Liu
- State Key Laboratory for Molecular Biology of Special Economic Animals, Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Changchun, People's Republic of China
| | - Yu Han
- Department of Joint Surgery, No. 1 Hospital of Jilin University, Changchun, People's Republic of China
| | - Xingyu Zhao
- Department of Joint Surgery, No. 1 Hospital of Jilin University, Changchun, People's Republic of China
| | - Bo Li
- State Key Laboratory for Molecular Biology of Special Economic Animals, Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Changchun, People's Republic of China.,Department of Joint Surgery, No. 1 Hospital of Jilin University, Changchun, People's Republic of China
| | - Liwen Xu
- State Key Laboratory for Molecular Biology of Special Economic Animals, Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Changchun, People's Republic of China
| | - Dongsong Li
- Department of Joint Surgery, No. 1 Hospital of Jilin University, Changchun, People's Republic of China
| | - Guangyu Li
- State Key Laboratory for Molecular Biology of Special Economic Animals, Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Changchun, People's Republic of China
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Ryczko D, Hanini‐Daoud M, Condamine S, Bréant BJB, Fougère M, Araya R, Kolta A. S100β‐mediated astroglial control of firing and input processing in layer 5 pyramidal neurons of the mouse visual cortex. J Physiol 2020; 599:677-707. [DOI: 10.1113/jp280501] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 11/23/2020] [Indexed: 12/18/2022] Open
Affiliation(s)
- Dimitri Ryczko
- Département de Neurosciences Université de Montréal Montréal QC Canada
- Département de Pharmacologie‐Physiologie Université de Sherbrooke Sherbrooke QC Canada
- Centre de recherche du CHUS Sherbrooke QC Canada
- Institut de Pharmacologie de Sherbrooke Sherbrooke QC Canada
- Centre d'excellence en neurosciences de l'Université de Sherbrooke Sherbrooke QC Canada
| | | | - Steven Condamine
- Département de Neurosciences Université de Montréal Montréal QC Canada
| | | | - Maxime Fougère
- Département de Pharmacologie‐Physiologie Université de Sherbrooke Sherbrooke QC Canada
| | - Roberto Araya
- Département de Neurosciences Université de Montréal Montréal QC Canada
| | - Arlette Kolta
- Département de Neurosciences Université de Montréal Montréal QC Canada
- Faculté de Médecine Dentaire Université de Montréal Montréal QC Canada
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Liang Y, Walczak P. Long term intravital single cell tracking under multiphoton microscopy. J Neurosci Methods 2020; 349:109042. [PMID: 33340557 DOI: 10.1016/j.jneumeth.2020.109042] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 12/07/2020] [Accepted: 12/11/2020] [Indexed: 12/13/2022]
Abstract
Visualizing and tracking cells over time in a living organism has been a much-coveted dream before the invention of intravital microscopy. The opaque nature of tissue was a major hurdle that was remedied by the multiphoton microscopy. With the advancement of optical imaging and fluorescent labeling tools, intravital high resolution imaging has become increasingly accessible over the past few years. Long-term intravital tracking of single cells (LIST) under multiphoton microscopy provides a unique opportunity to gain insight into the longitudinal changes in the morphology, migration, or function of cells or subcellular structures. It is particularly suitable for studying slow-evolving cellular and molecular events during normal development or disease progression, without losing the opportunity of catching fast events such as calcium signals. Here, we review the application of LIST under 2-photon microscopy in various fields of neurobiology and discuss challenges and new directions in labeling and imaging methods for LIST. Overall, this review provides an overview of current applications of LIST in mammals, which is an emerging field that will contribute to a better understanding of essential molecular and cellular events in health and disease.
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Affiliation(s)
- Yajie Liang
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.
| | - Piotr Walczak
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
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