1
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Sirko S, Schichor C, Della Vecchia P, Metzger F, Sonsalla G, Simon T, Bürkle M, Kalpazidou S, Ninkovic J, Masserdotti G, Sauniere JF, Iacobelli V, Iacobelli S, Delbridge C, Hauck SM, Tonn JC, Götz M. Injury-specific factors in the cerebrospinal fluid regulate astrocyte plasticity in the human brain. Nat Med 2023; 29:3149-3161. [PMID: 38066208 PMCID: PMC10719094 DOI: 10.1038/s41591-023-02644-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2022] [Accepted: 10/13/2023] [Indexed: 12/17/2023]
Abstract
The glial environment influences neurological disease progression, yet much of our knowledge still relies on preclinical animal studies, especially regarding astrocyte heterogeneity. In murine models of traumatic brain injury, beneficial functions of proliferating reactive astrocytes on disease outcome have been unraveled, but little is known regarding if and when they are present in human brain pathology. Here we examined a broad spectrum of pathologies with and without intracerebral hemorrhage and found a striking correlation between lesions involving blood-brain barrier rupture and astrocyte proliferation that was further corroborated in an assay probing for neural stem cell potential. Most importantly, proteomic analysis unraveled a crucial signaling pathway regulating this astrocyte plasticity with GALECTIN3 as a novel marker for proliferating astrocytes and the GALECTIN3-binding protein LGALS3BP as a functional hub mediating astrocyte proliferation and neurosphere formation. Taken together, this work identifies a therapeutically relevant astrocyte response and their molecular regulators in different pathologies affecting the human cerebral cortex.
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Affiliation(s)
- Swetlana Sirko
- Chair of Physiological Genomics, Biomedical Center (BMC), Faculty of Medicine, LMU Munich, Planegg-Martinsried, Germany.
- Institute of Stem Cell Research, Helmholtz Center München, Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Neuherberg, Germany.
| | - Christian Schichor
- Department of Neurosurgery, LMU University Hospital, LMU Munich, Munich, Germany
| | - Patrizia Della Vecchia
- Chair of Physiological Genomics, Biomedical Center (BMC), Faculty of Medicine, LMU Munich, Planegg-Martinsried, Germany
| | | | - Giovanna Sonsalla
- Chair of Physiological Genomics, Biomedical Center (BMC), Faculty of Medicine, LMU Munich, Planegg-Martinsried, Germany
- Institute of Stem Cell Research, Helmholtz Center München, Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Neuherberg, Germany
| | - Tatiana Simon
- Chair of Physiological Genomics, Biomedical Center (BMC), Faculty of Medicine, LMU Munich, Planegg-Martinsried, Germany
| | - Martina Bürkle
- Chair of Physiological Genomics, Biomedical Center (BMC), Faculty of Medicine, LMU Munich, Planegg-Martinsried, Germany
| | - Sofia Kalpazidou
- Chair of Cell Biology, Biomedical Center (BMC), Faculty of Medicine, LMU Munich, Planegg-Martinsried, Germany
| | - Jovica Ninkovic
- Institute of Stem Cell Research, Helmholtz Center München, Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Neuherberg, Germany
- Chair of Cell Biology, Biomedical Center (BMC), Faculty of Medicine, LMU Munich, Planegg-Martinsried, Germany
- SYNERGY Excellence Cluster of Systems Neurology, LMU Munich, Munich, Germany
| | - Giacomo Masserdotti
- Chair of Physiological Genomics, Biomedical Center (BMC), Faculty of Medicine, LMU Munich, Planegg-Martinsried, Germany
- Institute of Stem Cell Research, Helmholtz Center München, Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Neuherberg, Germany
| | | | | | | | - Claire Delbridge
- Department of Neuropathology, Institute of Pathology, TUM School of Medicine, TU Munich, Munich, Germany
| | - Stefanie M Hauck
- Research Unit Protein Science and Metabolomics and Proteomics Core, Helmholtz Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Neuherberg, Germany
| | - Jörg-Christian Tonn
- Department of Neurosurgery, LMU University Hospital, LMU Munich, Munich, Germany
| | - Magdalena Götz
- Chair of Physiological Genomics, Biomedical Center (BMC), Faculty of Medicine, LMU Munich, Planegg-Martinsried, Germany.
- Institute of Stem Cell Research, Helmholtz Center München, Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Neuherberg, Germany.
- SYNERGY Excellence Cluster of Systems Neurology, LMU Munich, Munich, Germany.
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2
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Villablanca C, Vidal R, Gonzalez-Billault C. Are cytoskeleton changes observed in astrocytes functionally linked to aging? Brain Res Bull 2023; 196:59-67. [PMID: 36935053 DOI: 10.1016/j.brainresbull.2023.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 02/22/2023] [Accepted: 03/16/2023] [Indexed: 03/19/2023]
Abstract
Astrocytes are active participants in the performance of the Central Nervous System (CNS) in both health and disease. During aging, astrocytes are susceptible to reactive astrogliosis, a molecular state characterized by functional changes in response to pathological situations, and cellular senescence, characterized by loss of cell division, apoptosis resistance, and gain of proinflammatory functions. This results in two different states of astrocytes, which can produce proinflammatory phenotypes with harmful consequences in chronic conditions. Reactive astrocytes and senescent astrocytes share morpho-functional features that are dependent on the organization of the cytoskeleton. However, such changes in the cytoskeleton have yet to receive the necessary attention to explain their role in the alterations of astrocytes that are associated with aging and pathologies. In this review, we summarize all the available findings that connect changes in the cytoskeleton of the astrocytes with aging. In addition, we discuss future avenues that we believe will guide such a novel topic.
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Affiliation(s)
- Cristopher Villablanca
- Laboratory of Cell and Neuronal Dynamics, Department of Biology, Faculty of Sciences, Universidad de Chile, Santiago, Chile; Center for Integrative Biology, Universidad Mayor, Santiago, Chile; Geroscience Center for Brain Health and Metabolism (GERO), Santiago, Chile
| | - René Vidal
- Laboratory of Cell and Neuronal Dynamics, Department of Biology, Faculty of Sciences, Universidad de Chile, Santiago, Chile; Center for Integrative Biology, Universidad Mayor, Santiago, Chile; Geroscience Center for Brain Health and Metabolism (GERO), Santiago, Chile
| | - Christian Gonzalez-Billault
- Laboratory of Cell and Neuronal Dynamics, Department of Biology, Faculty of Sciences, Universidad de Chile, Santiago, Chile; Geroscience Center for Brain Health and Metabolism (GERO), Santiago, Chile; Department of Neurosciences, Faculty of Medicine, Universidad de Chile, Santiago, Chile; Institute for Nutrition and Food Technologies, Universidad de Chile, Santiago, Chile.
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3
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Rawji KS, Neumann B, Franklin RJM. Glial aging and its impact on central nervous system myelin regeneration. Ann N Y Acad Sci 2023; 1519:34-45. [PMID: 36398864 DOI: 10.1111/nyas.14933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Aging is a major risk factor for several neurodegenerative diseases and is associated with cognitive decline. In addition to affecting neuronal function, the aging process significantly affects the functional phenotype of the glial cell compartment, comprising oligodendrocyte lineage cells, astrocytes, and microglia. These changes result in a more inflammatory microenvironment, resulting in a condition that is favorable for neuron and synapse loss. In addition to facilitating neurodegeneration, the aging glial cell population has negative implications for central nervous system remyelination, a regenerative process that is of particular importance to the chronic demyelinating disease multiple sclerosis. This review will discuss the changes that occur with aging in the three main glial populations and provide an overview of the studies documenting the impact these changes have on remyelination.
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Affiliation(s)
- Khalil S Rawji
- Altos Labs, Cambridge Institute of Science, Cambridge, UK
| | - Björn Neumann
- Altos Labs, Cambridge Institute of Science, Cambridge, UK
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4
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Thomas J, Martinez-Reza MF, Thorwirth M, Zarb Y, Conzelmann KK, Hauck SM, Grade S, Götz M. Excessive local host-graft connectivity in aging and amyloid-loaded brain. SCIENCE ADVANCES 2022; 8:eabg9287. [PMID: 35687689 PMCID: PMC9187230 DOI: 10.1126/sciadv.abg9287] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 04/25/2022] [Indexed: 05/24/2023]
Abstract
Transplantation is a clinically relevant approach for brain repair, but much remains to be understood about influences of the disease environment on transplant connectivity. To explore the effect of amyloid pathology in Alzheimer's disease (AD) and aging, we examined graft connectivity using monosynaptic rabies virus tracing in APP/PS1 mice and in 16- to 18-month-old wild-type (WT) mice. Transplanted neurons differentiated within 4 weeks and integrated well into the host visual cortex, receiving input from the appropriate brain regions for this area. Unexpectedly, we found a prominent several-fold increase in local inputs, in both amyloid-loaded and aged environments. State-of-the-art deep proteome analysis using mass spectrometry highlights complement system activation as a common denominator of environments promoting excessive local input connectivity. These data therefore reveal the key role of the host pathology in shaping the input connectome, calling for caution in extrapolating results from one pathological condition to another.
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Affiliation(s)
- Judith Thomas
- Physiological Genomics, Biomedical Center (BMC), Ludwig-Maximilians Universitaet Muenchen, D-82152 Planegg, Germany
- Institute of Stem Cell Research, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, D-85764 Neuherberg, Germany
- Graduate School of Systemic Neurosciences, Ludwig-Maximilians Universitaet Muenchen, D-82152 Planegg, Germany
| | - Maria Fernanda Martinez-Reza
- Physiological Genomics, Biomedical Center (BMC), Ludwig-Maximilians Universitaet Muenchen, D-82152 Planegg, Germany
- Institute of Stem Cell Research, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, D-85764 Neuherberg, Germany
- Graduate School of Systemic Neurosciences, Ludwig-Maximilians Universitaet Muenchen, D-82152 Planegg, Germany
| | - Manja Thorwirth
- Physiological Genomics, Biomedical Center (BMC), Ludwig-Maximilians Universitaet Muenchen, D-82152 Planegg, Germany
- Institute of Stem Cell Research, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, D-85764 Neuherberg, Germany
| | - Yvette Zarb
- Physiological Genomics, Biomedical Center (BMC), Ludwig-Maximilians Universitaet Muenchen, D-82152 Planegg, Germany
- Institute of Stem Cell Research, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, D-85764 Neuherberg, Germany
| | - Karl-Klaus Conzelmann
- Max von Pettenkofer-Institute of Virology, Medical Faculty and Gene Center, Ludwig-Maximilians Universitaet Muenchen, D-81377 Muenchen, Germany
| | - Stefanie M. Hauck
- Research Unit Protein Science and Metabolomics and Proteomics Core, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, D-85764 Neuherberg, Germany
| | - Sofia Grade
- Physiological Genomics, Biomedical Center (BMC), Ludwig-Maximilians Universitaet Muenchen, D-82152 Planegg, Germany
- Institute of Stem Cell Research, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, D-85764 Neuherberg, Germany
| | - Magdalena Götz
- Physiological Genomics, Biomedical Center (BMC), Ludwig-Maximilians Universitaet Muenchen, D-82152 Planegg, Germany
- Institute of Stem Cell Research, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, D-85764 Neuherberg, Germany
- SYNERGY, Excellence Cluster for Systems Neurology, Ludwig-Maximilians Universitaet Muenchen, D-82152 Planegg, Germany
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5
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Ohlig S, Clavreul S, Thorwirth M, Simon-Ebert T, Bocchi R, Ulbricht S, Kannayian N, Rossner M, Sirko S, Smialowski P, Fischer-Sternjak J, Götz M. Molecular diversity of diencephalic astrocytes reveals adult astrogenesis regulated by Smad4. EMBO J 2021; 40:e107532. [PMID: 34549820 PMCID: PMC8561644 DOI: 10.15252/embj.2020107532] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 08/09/2021] [Accepted: 08/19/2021] [Indexed: 12/16/2022] Open
Abstract
Astrocytes regulate brain‐wide functions and also show region‐specific differences, but little is known about how general and region‐specific functions are aligned at the single‐cell level. To explore this, we isolated adult mouse diencephalic astrocytes by ACSA‐2‐mediated magnetic‐activated cell sorting (MACS). Single‐cell RNA‐seq revealed 7 gene expression clusters of astrocytes, with 4 forming a supercluster. Within the supercluster, cells differed by gene expression related to ion homeostasis or metabolism, with the former sharing gene expression with other regions and the latter being restricted to specific regions. All clusters showed expression of proliferation‐related genes, and proliferation of diencephalic astrocytes was confirmed by immunostaining. Clonal analysis demonstrated low level of astrogenesis in the adult diencephalon, but not in cerebral cortex grey matter. This led to the identification of Smad4 as a key regulator of diencephalic astrocyte in vivo proliferation and in vitro neurosphere formation. Thus, astrocytes show diverse gene expression states related to distinct functions with some subsets being more widespread while others are more regionally restricted. However, all share low‐level proliferation revealing the novel concept of adult astrogenesis in the diencephalon.
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Affiliation(s)
- Stefanie Ohlig
- Biomedical Center (BMC), Division of Physiological Genomics, Faculty of Medicine, LMU Munich, Munich, Germany.,Helmholtz Zentrum Muenchen, German Research Center for Environmental Health (GmbH), Institute of Stem Cell Research, Neuherberg, Germany
| | - Solène Clavreul
- Biomedical Center (BMC), Division of Physiological Genomics, Faculty of Medicine, LMU Munich, Munich, Germany.,Helmholtz Zentrum Muenchen, German Research Center for Environmental Health (GmbH), Institute of Stem Cell Research, Neuherberg, Germany
| | - Manja Thorwirth
- Biomedical Center (BMC), Division of Physiological Genomics, Faculty of Medicine, LMU Munich, Munich, Germany.,Helmholtz Zentrum Muenchen, German Research Center for Environmental Health (GmbH), Institute of Stem Cell Research, Neuherberg, Germany
| | - Tatiana Simon-Ebert
- Biomedical Center (BMC), Division of Physiological Genomics, Faculty of Medicine, LMU Munich, Munich, Germany.,Helmholtz Zentrum Muenchen, German Research Center for Environmental Health (GmbH), Institute of Stem Cell Research, Neuherberg, Germany
| | - Riccardo Bocchi
- Biomedical Center (BMC), Division of Physiological Genomics, Faculty of Medicine, LMU Munich, Munich, Germany.,Helmholtz Zentrum Muenchen, German Research Center for Environmental Health (GmbH), Institute of Stem Cell Research, Neuherberg, Germany
| | - Sabine Ulbricht
- Biomedical Center (BMC), Division of Physiological Genomics, Faculty of Medicine, LMU Munich, Munich, Germany.,Helmholtz Zentrum Muenchen, German Research Center for Environmental Health (GmbH), Institute of Stem Cell Research, Neuherberg, Germany
| | - Nirmal Kannayian
- Molecular Neurobiology, Department of Psychiatry, LMU Munich, Munich, Germany
| | - Moritz Rossner
- Molecular Neurobiology, Department of Psychiatry, LMU Munich, Munich, Germany
| | - Swetlana Sirko
- Biomedical Center (BMC), Division of Physiological Genomics, Faculty of Medicine, LMU Munich, Munich, Germany.,Helmholtz Zentrum Muenchen, German Research Center for Environmental Health (GmbH), Institute of Stem Cell Research, Neuherberg, Germany
| | - Pawel Smialowski
- Biomedical Center (BMC), Division of Physiological Genomics, Faculty of Medicine, LMU Munich, Munich, Germany.,Helmholtz Zentrum Muenchen, German Research Center for Environmental Health (GmbH), Institute of Stem Cell Research, Neuherberg, Germany
| | - Judith Fischer-Sternjak
- Biomedical Center (BMC), Division of Physiological Genomics, Faculty of Medicine, LMU Munich, Munich, Germany.,Helmholtz Zentrum Muenchen, German Research Center for Environmental Health (GmbH), Institute of Stem Cell Research, Neuherberg, Germany
| | - Magdalena Götz
- Biomedical Center (BMC), Division of Physiological Genomics, Faculty of Medicine, LMU Munich, Munich, Germany.,Helmholtz Zentrum Muenchen, German Research Center for Environmental Health (GmbH), Institute of Stem Cell Research, Neuherberg, Germany.,SYNERGY, Excellence cluster of Systems Neurology, LMU Munich, Munich, Germany
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6
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Völkner M, Kurth T, Schor J, Ebner LJA, Bardtke L, Kavak C, Hackermüller J, Karl MO. Mouse Retinal Organoid Growth and Maintenance in Longer-Term Culture. Front Cell Dev Biol 2021; 9:645704. [PMID: 33996806 PMCID: PMC8114082 DOI: 10.3389/fcell.2021.645704] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 03/11/2021] [Indexed: 12/14/2022] Open
Abstract
Using retinal organoid systems, organ-like 3D tissues, relies implicitly on their robustness. However, essential key parameters, particularly retinal growth and longer-term culture, are still insufficiently defined. Here, we hypothesize that a previously optimized protocol for high yield of evenly-sized mouse retinal organoids with low variability facilitates assessment of such parameters. We demonstrate that these organoids reliably complete retinogenesis, and can be maintained at least up to 60 days in culture. During this time, the organoids continue to mature on a molecular and (ultra)structural level: They develop photoreceptor outer segments and synapses, transiently maintain its cell composition for about 5-10 days after completing retinogenesis, and subsequently develop pathologic changes - mainly of the inner but also outer retina and reactive gliosis. To test whether this organoid system provides experimental access to the retina during and upon completion of development, we defined and stimulated organoid growth by activating sonic hedgehog signaling, which in patients and mice in vivo with a congenital defect leads to enlarged eyes. Here, a sonic hedgehog signaling activator increased retinal epithelia length in the organoid system when applied during but not after completion of development. This experimentally supports organoid maturation, stability, and experimental reproducibility in this organoid system, and provides a potential enlarged retina pathology model, as well as a protocol for producing larger organoids. Together, our study advances the understanding of retinal growth, maturation, and maintenance, and further optimizes the organoid system for future utilization.
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Affiliation(s)
- Manuela Völkner
- German Center for Neurodegenerative Diseases (DZNE) Dresden, Dresden, Germany
| | - Thomas Kurth
- Center for Molecular and Cellular Bioengineering, Technology Platform, Electron Microscopy and Histology Facility, Technische Universität Dresden, Dresden, Germany
| | - Jana Schor
- Young Investigators Group Bioinformatics and Transcriptomics, Department Molecular Systems Biology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Lynn J A Ebner
- German Center for Neurodegenerative Diseases (DZNE) Dresden, Dresden, Germany
| | - Lara Bardtke
- German Center for Neurodegenerative Diseases (DZNE) Dresden, Dresden, Germany
| | - Cagri Kavak
- German Center for Neurodegenerative Diseases (DZNE) Dresden, Dresden, Germany
| | - Jörg Hackermüller
- Young Investigators Group Bioinformatics and Transcriptomics, Department Molecular Systems Biology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Mike O Karl
- German Center for Neurodegenerative Diseases (DZNE) Dresden, Dresden, Germany.,CRTD - Center for Regenerative Therapies Dresden, Technische Universität Dresden, Dresden, Germany
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7
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Sofroniew MV. Astrocyte Reactivity: Subtypes, States, and Functions in CNS Innate Immunity. Trends Immunol 2020; 41:758-770. [PMID: 32819810 DOI: 10.1016/j.it.2020.07.004] [Citation(s) in RCA: 355] [Impact Index Per Article: 88.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 07/05/2020] [Accepted: 07/09/2020] [Indexed: 12/12/2022]
Abstract
Astrocytes are neural parenchymal cells that ubiquitously tile the central nervous system (CNS). In addition to playing essential roles in healthy tissue, astrocytes exhibit an evolutionarily ancient response to all CNS insults, referred to as astrocyte reactivity. Long regarded as passive and homogeneous, astrocyte reactivity is being revealed as a heterogeneous and functionally powerful component of mammalian CNS innate immunity. Nevertheless, concepts about what astrocyte reactivity comprises and what it does are incomplete and sometimes controversial. This review discusses the goal of differentiating reactive astrocyte subtypes and states based on composite pictures of molecular expression, cell morphology, cellular interactions, proliferative state, normal functions, and disease-induced dysfunctions. A working model and conceptual framework is presented for characterizing the diversity of astrocyte reactivity.
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Affiliation(s)
- Michael V Sofroniew
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA.
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8
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Lange Canhos L, Chen M, Falk S, Popper B, Straub T, Götz M, Sirko S. Repetitive injury and absence of monocytes promote astrocyte self-renewal and neurological recovery. Glia 2020; 69:165-181. [PMID: 32744730 DOI: 10.1002/glia.23893] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 07/07/2020] [Accepted: 07/08/2020] [Indexed: 12/24/2022]
Abstract
Unlike microglia and NG2 glia, astrocytes are incapable of migrating to sites of injury in the posttraumatic cerebral cortex, instead relying on proliferation to replenish their numbers and distribution in the affected region. However, neither the spectrum of their proliferative repertoire nor their postinjury distribution has been examined in vivo. Using a combination of different thymidine analogs and clonal analysis in a model of repetitive traumatic brain injury, we show for the first time that astrocytes that are quiescent following an initial injury can be coerced to proliferate after a repeated insult in the cerebral cortex grey matter. Interestingly, this process is promoted by invasion of monocytes to the injury site, as their genetic ablation (using CCR2-/- mice) increased the number of repetitively dividing astrocytes at the expense of newly proliferating astrocytes in repeatedly injured parenchyma. These differences profoundly affected both the distribution of astrocytes and recovery period for posttraumatic behavior deficits suggesting key roles of astrocyte self-renewal in brain repair after injury.
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Affiliation(s)
- Luisa Lange Canhos
- Physiological Genomics, Biomedical Center, Ludwig-Maximilians-University Munich, Munich, Germany.,Institute of Stem Cell Research, Helmholtz Zentrum Munich, Neuherberg, Germany.,Graduate School of Systemic Neurosciences (GSN-LMU), Ludwig-Maximilians-University Munich, Munich, Germany
| | - Muxin Chen
- Physiological Genomics, Biomedical Center, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Sven Falk
- Physiological Genomics, Biomedical Center, Ludwig-Maximilians-University Munich, Munich, Germany.,Institute of Stem Cell Research, Helmholtz Zentrum Munich, Neuherberg, Germany
| | - Bastian Popper
- Core Facility Animal Models, Biomedical Center, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Tobias Straub
- Core Facility Bioinformatics, Biomedical Center, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Magdalena Götz
- Physiological Genomics, Biomedical Center, Ludwig-Maximilians-University Munich, Munich, Germany.,Institute of Stem Cell Research, Helmholtz Zentrum Munich, Neuherberg, Germany.,Excellence Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Swetlana Sirko
- Physiological Genomics, Biomedical Center, Ludwig-Maximilians-University Munich, Munich, Germany.,Institute of Stem Cell Research, Helmholtz Zentrum Munich, Neuherberg, Germany
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9
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Rawji KS, Gonzalez Martinez GA, Sharma A, Franklin RJ. The Role of Astrocytes in Remyelination. Trends Neurosci 2020; 43:596-607. [DOI: 10.1016/j.tins.2020.05.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 05/05/2020] [Accepted: 05/26/2020] [Indexed: 12/21/2022]
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10
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Osorio D, Pinzón A, Martín-Jiménez C, Barreto GE, González J. Multiple Pathways Involved in Palmitic Acid-Induced Toxicity: A System Biology Approach. Front Neurosci 2020; 13:1410. [PMID: 32076395 PMCID: PMC7006434 DOI: 10.3389/fnins.2019.01410] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 12/12/2019] [Indexed: 01/26/2023] Open
Abstract
Inflammation is a complex biological response to injuries, metabolic disorders or infections. In the brain, astrocytes play an important role in the inflammatory processes during neurodegenerative diseases. Recent studies have shown that the increase of free saturated fatty acids such as palmitic acid produces a metabolic inflammatory response in astrocytes generally associated with damaging mechanisms such as oxidative stress, endoplasmic reticulum stress, and autophagic defects. In this aspect, the synthetic neurosteroid tibolone has shown to exert protective functions against inflammation in neuronal experimental models without the tumorigenic effects exerted by sexual hormones such as estradiol and progesterone. However, there is little information regarding the specific mechanisms of tibolone in astrocytes during inflammatory insults. In the present study, we performed a genome-scale metabolic reconstruction of astrocytes that was used to study astrocytic response during an inflammatory insult by palmitate through Flux Balance Analysis methods and data mining. In this aspect, we assessed the metabolic fluxes of human astrocytes under three different scenarios: healthy (normal conditions), induced inflammation by palmitate, and tibolone treatment under palmitate inflammation. Our results suggest that tibolone reduces the L-glutamate-mediated neurotoxicity in astrocytes through the modulation of several metabolic pathways involved in glutamate uptake. We also identified a set of reactions associated with the protective effects of tibolone, including the upregulation of taurine metabolism, gluconeogenesis, cPPAR and the modulation of calcium signaling pathways. In conclusion, the different scenarios studied in our model allowed us to identify several metabolic fluxes perturbed under an inflammatory response and the protective mechanisms exerted by tibolone.
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Affiliation(s)
- Daniel Osorio
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, United States
| | - Andrés Pinzón
- Laboratorio de Bioinformática y Biología de Sistemas, Universidad Nacional de Colombia, Bogotá, Colombia
| | - Cynthia Martín-Jiménez
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - George E. Barreto
- Department of Biological Sciences, University of Limerick, Limerick, Ireland
- Health Research Institute, University of Limerick, Limerick, Ireland
| | - Janneth González
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia
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11
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Heimann G, Sirko S. Investigating Age-Related Changes in Proliferation and the Cell Division Repertoire of Parenchymal Reactive Astrocytes. Methods Mol Biol 2019; 1938:277-292. [PMID: 30617988 DOI: 10.1007/978-1-4939-9068-9_20] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Reactive gliosis is a complicated process involving all types of glial cells and is the therapeutic target of efforts to treat several types of neuropathologies. Parenchymal astrocytes continuously survey their microenvironment to identify even tiny abnormalities in the central nervous system (CNS) homeostasis and react rapidly to brain damage, such as following ischemia, trauma, or neurodegenerative diseases, to prevent propagation of tissue damage. Aging can play causal roles in certain astroglial dysfunctions, however, still little is known to what extent the heterogeneous reaction of astrocytes at the injury site might be impaired over the course of aging. Based on our experience with both in vitro and in vivo experimental paradigms, we describe here in detail the analysis of age-related changes in (1) proliferative response of parenchymal astrocytes within the posttraumatic cerebral cortex grey matter (GM), and (2) repertoire of their cell divisions in adherent cell culture prepared from the injured GM of young and old double transgenic GFAP-mRFP1/(FUCCI)-S/G2/M-mAG-hGeminin mice by single cell time-lapse imaging.
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Affiliation(s)
- Gábor Heimann
- Physiological Genomics, Biomedical Center, Ludwig-Maximilians-University, Munch, Germany
| | - Swetlana Sirko
- Physiological Genomics, Biomedical Center, Ludwig-Maximilians-University, Munch, Germany.
- Institute of Stem Cell Research, Helmholtz Center Munich, Neuherberg, Germany.
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Kaczmarek-Hajek K, Zhang J, Kopp R, Grosche A, Rissiek B, Saul A, Bruzzone S, Engel T, Jooss T, Krautloher A, Schuster S, Magnus T, Stadelmann C, Sirko S, Koch-Nolte F, Eulenburg V, Nicke A. Re-evaluation of neuronal P2X7 expression using novel mouse models and a P2X7-specific nanobody. eLife 2018; 7:36217. [PMID: 30074479 PMCID: PMC6140716 DOI: 10.7554/elife.36217] [Citation(s) in RCA: 111] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 07/31/2018] [Indexed: 12/18/2022] Open
Abstract
The P2X7 channel is involved in the pathogenesis of various CNS diseases. An increasing number of studies suggest its presence in neurons where its putative functions remain controversial for more than a decade. To resolve this issue and to provide a model for analysis of P2X7 functions, we generated P2X7 BAC transgenic mice that allow visualization of functional EGFP-tagged P2X7 receptors in vivo. Extensive characterization of these mice revealed dominant P2X7-EGFP protein expression in microglia, Bergmann glia, and oligodendrocytes, but not in neurons. These findings were further validated by microglia- and oligodendrocyte-specific P2X7 deletion and a novel P2X7-specific nanobody. In addition to the first quantitative analysis of P2X7 protein expression in the CNS, we show potential consequences of its overexpression in ischemic retina and post-traumatic cerebral cortex grey matter. This novel mouse model overcomes previous limitations in P2X7 research and will help to determine its physiological roles and contribution to diseases. The human body relies on a molecule called ATP as an energy source and as a messenger. When cells die, for example if they are damaged or because of inflammation, they release large amounts of ATP into their environment. Their neighbors can detect the outpouring of ATP through specific receptors, the proteins that sit at the cell’s surface and can bind external agents. Scientists believe that one of these ATP-binding receptors, P2X7, responds to high levels of ATP by triggering a cascade of reactions that results in inflammation and cell death. P2X7 also seems to play a role in several brain diseases such as epilepsia and Alzheimer’s, but the exact mechanisms are not known. In particular, how this receptor is involved in the death of neurons is unclear, and researchers still debate whether P2X7 is present in neurons and in other types of brain cells. To answer this, Kaczmarek-Hájek, Zhang, Kopp et al. created genetically modified mice in which the P2X7 receptors carry a fluorescent dye. Powerful microscopes can pick up the light signal from the dye and help to reveal which cells have the receptors. These experiments show that neurons do not carry the protein; instead, P2X7 is present in certain brain cells that keep the neurons healthy. For example, it is found in the immune cells that ‘clean up’ the organ, and the cells that support and insulate neurons. Kaczmarek-Hájek et al. further provide preliminary data suggesting that, under certain conditions, if too many P2X7 receptors are present in these cells neuronal damage might be increased. It is therefore possible that the brain cells that carry P2X7 indirectly contribute to the death of neurons when large amounts of ATP are released. The genetically engineered mouse designed for the experiments could be used in further studies to dissect the role that P2X7 plays in diseases of the nervous system. In particular, this mouse model might help to understand whether the receptor could become a drug target for neurodegenerative conditions.
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Affiliation(s)
- Karina Kaczmarek-Hajek
- Department of Molecular Biology of Neuronal Signals, Max Planck Institute for Experimental Medicine, Göttingen, Germany
| | - Jiong Zhang
- Department of Molecular Biology of Neuronal Signals, Max Planck Institute for Experimental Medicine, Göttingen, Germany.,Walther Straub Institute for Pharmacology and Toxicology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Robin Kopp
- Walther Straub Institute for Pharmacology and Toxicology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Antje Grosche
- Institute for Human Genetics, University of Regensburg, Regensburg, Germany.,Department of Physiological Genomics, Ludwig-Maximilians-Universität München, München, Germany
| | - Björn Rissiek
- Department of Neurology, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Anika Saul
- Department of Molecular Biology of Neuronal Signals, Max Planck Institute for Experimental Medicine, Göttingen, Germany
| | - Santina Bruzzone
- Department of Experimental Medicine and CEBR, University of Genova, Genova, Italy
| | - Tobias Engel
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Tina Jooss
- Walther Straub Institute for Pharmacology and Toxicology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Anna Krautloher
- Walther Straub Institute for Pharmacology and Toxicology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Stefanie Schuster
- Institute of Biochemistry, University Erlangen-Nürnberg, Erlangen, Germany
| | - Tim Magnus
- Department of Neurology, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | | | - Swetlana Sirko
- Department of Physiological Genomics, Ludwig-Maximilians-Universität München, München, Germany.,Institute of Stem Cell Research, Helmholtz Center Munich, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
| | - Friedrich Koch-Nolte
- Department of Immunology, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Volker Eulenburg
- Institute of Biochemistry, University Erlangen-Nürnberg, Erlangen, Germany.,Department of Anaesthesiology and Intensive Care Therapy, University of Leipzig, Leipzig, Germany
| | - Annette Nicke
- Department of Molecular Biology of Neuronal Signals, Max Planck Institute for Experimental Medicine, Göttingen, Germany.,Walther Straub Institute for Pharmacology and Toxicology, Ludwig-Maximilians-Universität München, Munich, Germany
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Frik J, Merl-Pham J, Plesnila N, Mattugini N, Kjell J, Kraska J, Gómez RM, Hauck SM, Sirko S, Götz M. Cross-talk between monocyte invasion and astrocyte proliferation regulates scarring in brain injury. EMBO Rep 2018; 19:embr.201745294. [PMID: 29632244 PMCID: PMC5934774 DOI: 10.15252/embr.201745294] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 03/02/2018] [Accepted: 03/09/2018] [Indexed: 01/02/2023] Open
Abstract
Scar formation after brain injury is still poorly understood. To further elucidate such processes, here, we examine the interplay between astrocyte proliferation taking place predominantly at the vascular interface and monocyte invasion. Using genetic mouse models that decrease or increase reactive astrocyte proliferation, we demonstrate inverse effects on monocyte numbers in the injury site. Conversely, reducing monocyte invasion using CCR2-/- mice causes a strong increase in astrocyte proliferation, demonstrating an intriguing negative cross-regulation between these cell types at the vascular interface. CCR2-/- mice show reduced scar formation with less extracellular matrix deposition, smaller lesion site and increased neuronal coverage. Surprisingly, the GFAP+ scar area in these mice is also significantly decreased despite increased astrocyte proliferation. Proteomic analysis at the peak of increased astrocyte proliferation reveals a decrease in extracellular matrix synthesizing enzymes in the injury sites of CCR2-/- mice, highlighting how early key aspects of scar formation are initiated. Taken together, we provide novel insights into the cross-regulation of juxtavascular proliferating astrocytes and invading monocytes as a crucial mechanism of scar formation upon brain injury.
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Affiliation(s)
- Jesica Frik
- Physiological Genomics, Biomedical Center, Ludwig-Maximilians-University Munich, Munich, Germany.,Institute for Stem Cell Research, Helmholtz Center Munich, Munich, Germany.,Instituto de Biotecnología y Biología Molecular, UNLP-CONICET, La Plata, Argentina
| | - Juliane Merl-Pham
- Research Unit for Protein Science, Helmholtz Center Munich, Munich, Germany
| | - Nikolaus Plesnila
- Institute for Stroke and Dementia Research, Experimental Stroke Research, University of Munich Medical School, Munich, Germany.,SYNERGY, Excellence Cluster Systems Neurology, University of Munich, Munich, Germany
| | - Nicola Mattugini
- Physiological Genomics, Biomedical Center, Ludwig-Maximilians-University Munich, Munich, Germany.,Institute for Stem Cell Research, Helmholtz Center Munich, Munich, Germany.,Graduate School of Systemic Neurosciences, Biocenter, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Jacob Kjell
- Physiological Genomics, Biomedical Center, Ludwig-Maximilians-University Munich, Munich, Germany.,Institute for Stem Cell Research, Helmholtz Center Munich, Munich, Germany
| | - Jonas Kraska
- Physiological Genomics, Biomedical Center, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Ricardo M Gómez
- Instituto de Biotecnología y Biología Molecular, UNLP-CONICET, La Plata, Argentina
| | - Stefanie M Hauck
- Research Unit for Protein Science, Helmholtz Center Munich, Munich, Germany
| | - Swetlana Sirko
- Physiological Genomics, Biomedical Center, Ludwig-Maximilians-University Munich, Munich, Germany .,Institute for Stem Cell Research, Helmholtz Center Munich, Munich, Germany
| | - Magdalena Götz
- Physiological Genomics, Biomedical Center, Ludwig-Maximilians-University Munich, Munich, Germany .,Institute for Stem Cell Research, Helmholtz Center Munich, Munich, Germany.,SYNERGY, Excellence Cluster Systems Neurology, University of Munich, Munich, Germany
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Delaney C, Campbell M. The blood brain barrier: Insights from development and ageing. Tissue Barriers 2017; 5:e1373897. [PMID: 28956691 PMCID: PMC5788423 DOI: 10.1080/21688370.2017.1373897] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 08/25/2017] [Accepted: 08/26/2017] [Indexed: 12/29/2022] Open
Abstract
The blood brain barrier is a necessity for cerebral homeostasis and response to environmental insult, thus loss in functionality with age creates opportunities for disease to arise in the aged brain. Understanding how the barrier is developed and maintained throughout the earlier years of adult life can identify key processes that may have beneficial applications in the restoration of the aged brain. With an unprecedented increasing global aged population, the prevention and treatment of age-associated disorders has become a rising healthcare priority demanding novel approaches for the development of therapeutic strategies. The aging cardiovascular system has long been recognised to be a major factor in age-associated diseases such as stroke, atherosclerosis and cardiac arrest. Changes in the highly specialised cerebral vasculature may similarly drive neurodegenerative and neuropsychiatric disease.
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Affiliation(s)
- Conor Delaney
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
| | - Matthew Campbell
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
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