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Liu Y, Guo J, Matoga M, Korotkova M, Jakobsson PJ, Aguzzi A. NG2 glia protect against prion neurotoxicity by inhibiting microglia-to-neuron prostaglandin E2 signaling. Nat Neurosci 2024; 27:1534-1544. [PMID: 38802591 PMCID: PMC11303249 DOI: 10.1038/s41593-024-01663-x] [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: 04/10/2023] [Accepted: 04/22/2024] [Indexed: 05/29/2024]
Abstract
Oligodendrocyte-lineage cells, including NG2 glia, undergo prominent changes in various neurodegenerative disorders. Here, we identify a neuroprotective role for NG2 glia against prion toxicity. NG2 glia were activated after prion infection in cerebellar organotypic cultured slices (COCS) and in brains of prion-inoculated mice. In both model systems, depletion of NG2 glia exacerbated prion-induced neurodegeneration and accelerated prion pathology. Loss of NG2 glia enhanced the biosynthesis of prostaglandin E2 (PGE2) by microglia, which augmented prion neurotoxicity through binding to the EP4 receptor. Pharmacological or genetic inhibition of PGE2 biosynthesis attenuated prion-induced neurodegeneration in COCS and mice, reduced the enhanced neurodegeneration in NG2-glia-depleted COCS after prion infection, and dampened the acceleration of prion disease in NG2-glia-depleted mice. These data unveil a non-cell-autonomous interaction between NG2 glia and microglia in prion disease and suggest that PGE2 signaling may represent an actionable target against prion diseases.
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Affiliation(s)
- Yingjun Liu
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland.
| | - Jingjing Guo
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Maja Matoga
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Marina Korotkova
- Karolinska Institutet, Department of Medicine Solna, Division of Rheumatology, Stockholm, Sweden
- Karolinska University Hospital at Solna, Stockholm, Sweden
| | - Per-Johan Jakobsson
- Karolinska Institutet, Department of Medicine Solna, Division of Rheumatology, Stockholm, Sweden
- Karolinska University Hospital at Solna, Stockholm, Sweden
| | - Adriano Aguzzi
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland.
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2
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Mercer RCC, Le NTT, Fraser DG, Houser MCQ, Beeler AB, Harris DA. Sigma Receptor Ligands Are Potent Antiprion Compounds that Act Independently of Sigma Receptor Binding. ACS Chem Neurosci 2024; 15:2265-2282. [PMID: 38743607 DOI: 10.1021/acschemneuro.4c00095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2024] Open
Abstract
Prion diseases are invariably fatal neurodegenerative diseases of humans and other animals for which there are no effective treatment options. Previous work from our laboratory identified phenethylpiperidines as a novel class of anti-prion compounds. While working to identify the molecular target(s) of these molecules, we unexpectedly discovered ten novel antiprion compounds based on their known ability to bind to the sigma receptors, σ1R and σ2R, which are currently being tested as therapeutic or diagnostic targets for cancer and neuropsychiatric disorders. Surprisingly, however, knockout of the respective genes encoding σ1R and σ2R (Sigmar1 and Tmem97) in prion-infected N2a cells did not alter the antiprion activity of these compounds, demonstrating that these receptors are not the direct targets responsible for the antiprion effects of their ligands. Further investigation of the most potent molecules established that they are efficacious against multiple prion strains and protect against downstream prion-mediated synaptotoxicity. While the precise details of the mechanism of action of these molecules remain to be determined, the present work forms the basis for further investigation of these compounds in preclinical studies. Given the therapeutic utility of several of the tested compounds, including rimcazole and haloperidol for neuropsychiatric conditions, (+)-pentazocine for neuropathic pain, and the ongoing clinical trials of SA 4503 and ANAVEX2-73 for ischemic stroke and Alzheimer's disease, respectively, this work has immediate implications for the treatment of human prion disease.
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Affiliation(s)
- Robert C C Mercer
- Department of Biochemistry & Cell Biology, Boston University Chobanian & Avedisian School of Medicine, Boston, Massachusetts 02118, United States
| | - Nhat T T Le
- Department of Biochemistry & Cell Biology, Boston University Chobanian & Avedisian School of Medicine, Boston, Massachusetts 02118, United States
| | - Douglas G Fraser
- Department of Chemistry, Boston University, Boston, Massachusetts 02215, United States
| | - Mei C Q Houser
- Department of Biochemistry & Cell Biology, Boston University Chobanian & Avedisian School of Medicine, Boston, Massachusetts 02118, United States
| | - Aaron B Beeler
- Department of Chemistry, Boston University, Boston, Massachusetts 02215, United States
| | - David A Harris
- Department of Biochemistry & Cell Biology, Boston University Chobanian & Avedisian School of Medicine, Boston, Massachusetts 02118, United States
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Benarroch E. What Are the Roles of Cellular Prion Protein in Normal and Pathologic Conditions? Neurology 2024; 102:e209272. [PMID: 38484222 DOI: 10.1212/wnl.0000000000209272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Accepted: 01/11/2024] [Indexed: 03/19/2024] Open
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Shimamura T, Takeo Y, Moriya F, Kimura T, Shimura M, Senba Y, Kishimoto H, Ohashi H, Shimba K, Jimbo Y, Mimura H. Ultracompact mirror device for forming 20-nm achromatic soft-X-ray focus toward multimodal and multicolor nanoanalyses. Nat Commun 2024; 15:665. [PMID: 38326328 PMCID: PMC10850520 DOI: 10.1038/s41467-023-44269-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Accepted: 12/06/2023] [Indexed: 02/09/2024] Open
Abstract
Nanoscale soft-X-ray microscopy is a powerful analysis tool in biological, chemical, and physical sciences. To enhance its probe sensitivity and leverage multimodal soft-X-ray microscopy, precise achromatic focusing devices, which are challenging to fabricate, are essential. Here, we develop an ultracompact Kirkpatrick-Baez (ucKB) mirror, which is ideal for the high-performance nanofocusing of broadband-energy X-rays. We apply our advanced fabrication techniques and short-focal-length strategy to realize diffraction-limited focusing over the entire soft-X-ray range. We achieve a focus size of 20.4 nm at 2 keV, which represents a significant improvement in achromatic soft-X-ray focusing. The ucKB mirror extends soft-X-ray fluorescence microscopy by producing a bicolor nanoprobe with a 1- or 2-keV photon energy. We propose a subcellular chemical mapping method that allows a comprehensive analysis of specimen morphology and the distribution of light elements and metal elements. ucKB mirrors will improve soft-X-ray nanoanalyses by facilitating photon-hungry, multimodal, and polychromatic methods, even with table-top X-ray sources.
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Affiliation(s)
- Takenori Shimamura
- School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo, 113-8656, Japan.
- Japan Synchrotron Radiation Research Institute, 1-1-1 Koto, Sayo, Sayo District, Hyogo, 679-5198, Japan.
- The Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8581, Japan.
| | - Yoko Takeo
- Japan Synchrotron Radiation Research Institute, 1-1-1 Koto, Sayo, Sayo District, Hyogo, 679-5198, Japan
- The Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8581, Japan
| | - Fumika Moriya
- School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo, 113-8656, Japan
| | - Takashi Kimura
- The Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8581, Japan
| | - Mari Shimura
- RIKEN SPring-8 Center, 1-1-1 Koto, Sayo, Sayo District, Hyogo, 679-5148, Japan
- Department of Refractory Viral Infection, Research Institute, National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku, Tokyo, 162-8655, Japan
| | - Yasunori Senba
- Japan Synchrotron Radiation Research Institute, 1-1-1 Koto, Sayo, Sayo District, Hyogo, 679-5198, Japan
- RIKEN SPring-8 Center, 1-1-1 Koto, Sayo, Sayo District, Hyogo, 679-5148, Japan
| | - Hikaru Kishimoto
- Japan Synchrotron Radiation Research Institute, 1-1-1 Koto, Sayo, Sayo District, Hyogo, 679-5198, Japan
| | - Haruhiko Ohashi
- Japan Synchrotron Radiation Research Institute, 1-1-1 Koto, Sayo, Sayo District, Hyogo, 679-5198, Japan
- RIKEN SPring-8 Center, 1-1-1 Koto, Sayo, Sayo District, Hyogo, 679-5148, Japan
| | - Kenta Shimba
- School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo, 113-8656, Japan
| | - Yasuhiko Jimbo
- School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo, 113-8656, Japan
| | - Hidekazu Mimura
- RIKEN SPring-8 Center, 1-1-1 Koto, Sayo, Sayo District, Hyogo, 679-5148, Japan.
- Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo, 153-8904, Japan.
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Mercer RCC, Le NTT, Houser MCQ, Beeler AB, Harris DA. Sigma receptor ligands are potent anti-prion compounds that act independently of sigma receptor binding. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.28.569035. [PMID: 38077011 PMCID: PMC10705434 DOI: 10.1101/2023.11.28.569035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2024]
Abstract
Prion diseases are invariably fatal neurodegenerative diseases of humans and other animals for which there are no treatment options. Previous work from our laboratory identified phenethyl piperidines as novel class of anti-prion compounds. While working to identify the molecular target(s) of these molecules, we unexpectedly discovered ten novel anti-prion compounds based on their known ability to bind to the sigma receptors, σ 1 R and 2 R, which are currently being tested as therapeutic or diagnostic targets for cancer and neuropsychiatric disorders. Surprisingly, however, knockout of the respective genes encoding σ 1 R and σ 2 R ( Sigmar1 and Tmem97 ), in prion infected N2a cells did not alter the anti-prion activity of these compounds, demonstrating that these receptors are not the direct targets responsible the anti-prion effects of their ligands. Further investigation of the most potent molecules established that they are efficacious against multiple prion strains and protect against downstream prion-mediated synaptotoxicity. While the precise details of the mechanism of action of these molecules remains to be determined, the present work forms the basis for further investigations of these compounds in pre-clinical studies. Given the therapeutic utility of several of the tested compounds, including rimcazole and haloperidol for neuropsychiatric conditions, (+)-pentazocine for neuropathic pain, and the ongoing clinical trials of SA 4503 and ANAVEX2-73 for ischemic stroke and Alzheimer's disease, respectively, this work has immediate implications for the treatment of human prion disease.
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Bentivenga GM, Baiardi S, Mastrangelo A, Zenesini C, Mammana A, Polischi B, Capellari S, Parchi P. Diagnostic and prognostic value of cerebrospinal fluid SNAP-25 and neurogranin in Creutzfeldt-Jakob disease in a clinical setting cohort of rapidly progressive dementias. Alzheimers Res Ther 2023; 15:150. [PMID: 37684653 PMCID: PMC10485978 DOI: 10.1186/s13195-023-01300-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 08/27/2023] [Indexed: 09/10/2023]
Abstract
BACKGROUND The levels of synaptic markers synaptosomal-associated protein 25 (SNAP-25) and neurogranin (Ng) have been shown to increase early in the cerebrospinal fluid (CSF) of patients with Creutzfeldt-Jakob disease (CJD) and to have prognostic potential. However, no validation studies assessed these biomarkers' diagnostic and prognostic value in a large clinical setting cohort of rapidly progressive dementia. METHODS In this retrospective study, using commercially available immunoassays, we measured the levels of SNAP-25, Ng, 14-3-3, total-tau (t-tau), neurofilament light chain (NfL), and phospho-tau181 (p-tau) in CSF samples from consecutive patients with CJD (n = 220) or non-prion rapidly progressive dementia (np-RPD) (n = 213). We evaluated and compared the diagnostic accuracy of each CSF biomarker and biomarker combination by receiver operating characteristics curve (ROC) analyses, studied SNAP-25 and Ng CSF concentrations distribution across CJD subtypes, and estimated their association with survival using multivariable Cox regression analyses. RESULTS CSF SNAP-25 and Ng levels were higher in CJD than in np-RPD (SNAP-25: 582, 95% CI 240-1250 vs. 115, 95% CI 78-157 pg/ml, p < 0.0001; Ng: 841, 95% CI 411-1473 vs. 390, 95% CI 260-766 pg/ml, p < 0.001). SNAP-25 diagnostic accuracy (AUC 0.902, 95% CI 0.873-0.931) exceeded that of 14-3-3 (AUC 0.853, 95% CI 0.816-0.889), t-tau (AUC 0.878, 95% CI 0.845-0.901), and the t-tau/p-tau ratio (AUC 0.884, 95% CI 0.851-0.916). In contrast, Ng performed worse (AUC 0.697, 95% CI 0.626-0.767) than all other surrogate biomarkers, except for NfL (AUC 0.649, 95% CI 0.593-0.705). SNAP-25 maintained a relatively high diagnostic value even for atypical CJD subtypes (AUC 0.792, 95% CI 0.729-0.854). In Cox regression analyses, SNAP-25 levels were significantly associated with survival in CJD (hazard ratio [HR] 1.71 95% CI 1.40-2.09). Conversely, Ng was associated with survival only in the most rapidly progressive CJD subtypes (sCJD MM(V)1 and gCJD M1) (HR 1.81 95% CI 1.21-2.93). CONCLUSIONS In the clinical setting, CSF SNAP-25 is a viable alternative to t-tau, 14-3-3, and the t-tau/p-tau ratio in discriminating the CJD subtypes from other RPDs. Additionally, SNAP-25 and, to a lesser extent, Ng predict survival in CJD, showing prognostic power in the range of CSF t-tau/14-3-3 and NfL, respectively.
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Affiliation(s)
| | - Simone Baiardi
- Department of Biomedical and Neuromotor Sciences (DiBiNeM), University of Bologna, Bologna, Italy
| | - Andrea Mastrangelo
- Department of Biomedical and Neuromotor Sciences (DiBiNeM), University of Bologna, Bologna, Italy
| | - Corrado Zenesini
- IRCCS, Istituto delle Scienze Neurologiche di Bologna, Programma Neuropatologia delle Malattie Neurodegenerative, Bologna, Italy
| | - Angela Mammana
- IRCCS, Istituto delle Scienze Neurologiche di Bologna, Programma Neuropatologia delle Malattie Neurodegenerative, Bologna, Italy
| | - Barbara Polischi
- IRCCS, Istituto delle Scienze Neurologiche di Bologna, Programma Neuropatologia delle Malattie Neurodegenerative, Bologna, Italy
| | - Sabina Capellari
- Department of Biomedical and Neuromotor Sciences (DiBiNeM), University of Bologna, Bologna, Italy
- IRCCS, Istituto delle Scienze Neurologiche di Bologna, Programma Neuropatologia delle Malattie Neurodegenerative, Bologna, Italy
| | - Piero Parchi
- Department of Biomedical and Neuromotor Sciences (DiBiNeM), University of Bologna, Bologna, Italy.
- IRCCS, Istituto delle Scienze Neurologiche di Bologna, Programma Neuropatologia delle Malattie Neurodegenerative, Bologna, Italy.
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Pratsch K, Unemura C, Ito M, Lichtenthaler SF, Horiguchi N, Herms J. New Highly Selective BACE1 Inhibitors and Their Effects on Dendritic Spine Density In Vivo. Int J Mol Sci 2023; 24:12283. [PMID: 37569661 PMCID: PMC10418759 DOI: 10.3390/ijms241512283] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 07/27/2023] [Accepted: 07/28/2023] [Indexed: 08/13/2023] Open
Abstract
β-site amyloid precursor protein-cleaving enzyme 1 (BACE1) is considered a therapeutic target to combat Alzheimer's disease by reducing β-amyloid in the brain. To date, all clinical trials involving the inhibition of BACE1 have been discontinued due to a lack of efficacy or undesirable side effects such as cognitive worsening. The latter could have been the result of the inhibition of BACE at the synapse where it is expressed in high amounts. We have previously shown that prolonged inhibition of BACE interferes with structural synaptic plasticity, most likely due to the diminished processing of the physiological BACE substrate Seizure protein 6 (Sez6) which is exclusively processed by BACE1 and is required for dendritic spine plasticity. Given that BACE1 has significant amino acid similarity with its homolog BACE2, the inhibition of BACE2 may cause some of the side effects, as most BACE inhibitors do not discriminate between the two. In this study, we used newly developed BACE inhibitors that have a different chemotype from previously developed inhibitors and a high selectivity for BACE1 over BACE2. By using longitudinal in vivo two-photon microscopy, we investigated the effect on dendritic spine dynamics of pyramidal layer V neurons in the somatosensory cortex in mice treated with highly selective BACE1 inhibitors. Treatment with those inhibitors showed a reduction in soluble Sez6 (sSez6) levels to 27% (elenbecestat, Biogen, Eisai Co., Ltd., Tokyo, Japan), 17% (Shionogi compound 1) and 39% (Shionogi compound 2), compared to animals fed with vehicle pellets. We observed a significant decrease in the number of dendritic spines with Shionogi compound 1 after 21 days of treatment but not with Shionogi compound 2 or with elenbecestat, which did not show cognitive worsening in clinical trials. In conclusion, highly selective BACE1 inhibitors do alter dendritic spine density similar to non-selective inhibitors if soluble (sSez6) levels drop too much. Low-dose BACE1 inhibition might be reasonable if dosing is carefully adjusted to the amount of Sez6 cleavage, which can be easily monitored during the first week of treatment.
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Affiliation(s)
- Katrin Pratsch
- German Center for Neurodegenerative Diseases (DZNE), 81377 Munich, Germany; (K.P.); (S.F.L.)
- Munich Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany
- Center for Neuropathology and Prion Research (ZNP), Faculty of Medicine, LMU Munich, 81377 Munich, Germany
| | - Chie Unemura
- Laboratory for Drug Discovery and Disease Research, Shionogi & Co., Ltd., Shionogi Pharmaceutical Research Center, Osaka 561-0825, Japan; (C.U.); (M.I.); (N.H.)
| | - Mana Ito
- Laboratory for Drug Discovery and Disease Research, Shionogi & Co., Ltd., Shionogi Pharmaceutical Research Center, Osaka 561-0825, Japan; (C.U.); (M.I.); (N.H.)
| | - Stefan F. Lichtenthaler
- German Center for Neurodegenerative Diseases (DZNE), 81377 Munich, Germany; (K.P.); (S.F.L.)
- Munich Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany
- Neuroproteomics, School of Medicine, Klinikum Rechts der Isar, Technical University of Munich, 81675 Munich, Germany
| | - Naotaka Horiguchi
- Laboratory for Drug Discovery and Disease Research, Shionogi & Co., Ltd., Shionogi Pharmaceutical Research Center, Osaka 561-0825, Japan; (C.U.); (M.I.); (N.H.)
| | - Jochen Herms
- German Center for Neurodegenerative Diseases (DZNE), 81377 Munich, Germany; (K.P.); (S.F.L.)
- Munich Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany
- Center for Neuropathology and Prion Research (ZNP), Faculty of Medicine, LMU Munich, 81377 Munich, Germany
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Evano B, Sarde L, Tajbakhsh S. Temporal static and dynamic imaging of skeletal muscle in vivo. Exp Cell Res 2023; 424:113484. [PMID: 36693490 DOI: 10.1016/j.yexcr.2023.113484] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 01/13/2023] [Accepted: 01/15/2023] [Indexed: 01/22/2023]
Abstract
A major challenge in the study of living systems is understanding how tissues and organs are established, maintained during homeostasis, reconstituted following injury or deteriorated during disease. Most of the studies that interrogate in vivo cell biological properties of cell populations within tissues are obtained through static imaging approaches. However, in vertebrates, little is known about which, when, and how extracellular and intracellular signals are dynamically integrated to regulate cell behaviour and fates, due largely to technical challenges. Intravital imaging of cellular dynamics in mammalian models has exposed surprising properties that have been missed by conventional static imaging approaches. Here we highlight some selected examples of intravital imaging in mouse intestinal stem cells, hematopoietic stem cells, hair follicle stem cells, and neural stem cells in the brain, each of which have distinct features from an anatomical and niche-architecture perspective. Intravital imaging of mouse skeletal muscles is comparatively less advanced due to several technical constraints that will be discussed, yet this approach holds great promise as a complementary investigative method to validate findings obtained by static imaging, as well as a method for discovery.
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Affiliation(s)
- Brendan Evano
- Stem Cells and Development, Department of Developmental & Stem Cell Biology, Institut Pasteur, Université Paris Cité, Paris, 75015, France; CNRS UMR 3738, Institut Pasteur, Paris, 75015, France
| | - Liza Sarde
- Stem Cells and Development, Department of Developmental & Stem Cell Biology, Institut Pasteur, Université Paris Cité, Paris, 75015, France; CNRS UMR 3738, Institut Pasteur, Paris, 75015, France; Sorbonne Université, Complexité Du Vivant, F-75005, Paris, France
| | - Shahragim Tajbakhsh
- Stem Cells and Development, Department of Developmental & Stem Cell Biology, Institut Pasteur, Université Paris Cité, Paris, 75015, France; CNRS UMR 3738, Institut Pasteur, Paris, 75015, France.
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Villar-Pazos S, Thomas L, Yang Y, Chen K, Lyles JB, Deitch BJ, Ochaba J, Ling K, Powers B, Gingras S, Kordasiewicz HB, Grubisha MJ, Huang YH, Thomas G. RNA-targeted therapy corrects neuronal deficits in PACS1 syndrome mice. RESEARCH SQUARE 2023:rs.3.rs-2440581. [PMID: 36747781 PMCID: PMC9901029 DOI: 10.21203/rs.3.rs-2440581/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Neurodevelopmental disorders (NDDs) are frequently associated with dendritic abnormalities in pyramidal neurons that affect arbor complexity, spine density, and synaptic communication 1,2. The underlying genetic causes are often complex, obscuring the molecular pathways that drive these disorders 3. Next-generation sequencing has identified recurrent de novo missense mutations in a handful of genes associated with NDDs, offering a unique opportunity to decipher the molecular pathways 4. One such gene is PACS1, which encodes the multi-functional trafficking protein PACS1 (or PACS-1); a single recurrent de novo missense mutation, c607C>T (PACS1R203W), causes developmental delay and intellectual disability (ID) 5,6. The processes by which PACS1R203W causes PACS1 syndrome are unknown, and there is no curative treatment. We show that PACS1R203W increases the interaction between PACS1 and the α-tubulin deacetylase HDAC6, elevating enzyme activity and appropriating control of its posttranscriptional regulation. Consequently, PACS1R203W reduces acetylation of α-tubulin and cortactin, causing the Golgi to fragment and enter developing neurites, leading to increased dendrite arborization. The dendrites, however, are beset with diminished spine density and fewer functional synapses, characteristic of ID pathology. Treatment of PACS1 syndrome mice with PACS1- or HDAC6-targeting antisense oligonucleotides restores neuronal structure and synaptic transmission, suggesting PACS1R203W/HDAC6 may be targeted for treating PACS1 syndrome neuropathology.
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Affiliation(s)
- Sabrina Villar-Pazos
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Laurel Thomas
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Yunhan Yang
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Kun Chen
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Jenea B. Lyles
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Bradley J. Deitch
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | | | - Karen Ling
- Ionis Pharmaceuticals, Carlsbad, CA, USA
| | | | - Sebastien Gingras
- Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213
| | | | - Melanie J. Grubisha
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Translational Neuroscience Program, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Yanhua H. Huang
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Gary Thomas
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
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10
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Nebeling FC, Poll S, Justus LC, Steffen J, Keppler K, Mittag M, Fuhrmann M. Microglial motility is modulated by neuronal activity and correlates with dendritic spine plasticity in the hippocampus of awake mice. eLife 2023; 12:83176. [PMID: 36749020 PMCID: PMC9946443 DOI: 10.7554/elife.83176] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 02/03/2023] [Indexed: 02/08/2023] Open
Abstract
Microglia, the resident immune cells of the brain, play a complex role in health and disease. They actively survey the brain parenchyma by physically interacting with other cells and structurally shaping the brain. Yet, the mechanisms underlying microglial motility and significance for synapse stability, especially in the hippocampus during adulthood, remain widely unresolved. Here, we investigated the effect of neuronal activity on microglial motility and the implications for the formation and survival of dendritic spines on hippocampal CA1 neurons in vivo. We used repetitive two-photon in vivo imaging in the hippocampus of awake and anesthetized mice to simultaneously study the motility of microglia and their interaction with dendritic spines. We found that CA3 to CA1 input is sufficient to modulate microglial process motility. Simultaneously, more dendritic spines emerged in mice after awake compared to anesthetized imaging. Interestingly, the rate of microglial contacts with individual dendritic spines and dendrites was associated with the stability, removal, and emergence of dendritic spines. These results suggest that microglia might sense neuronal activity via neurotransmitter release and actively participate in synaptic rewiring of the hippocampal neural network during adulthood. Further, this study has profound relevance for hippocampal learning and memory processes.
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Affiliation(s)
| | - Stefanie Poll
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative DiseasesBonnGermany
| | - Lena Christine Justus
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative DiseasesBonnGermany
| | - Julia Steffen
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative DiseasesBonnGermany
| | - Kevin Keppler
- Light Microscopy Facility, German Center for Neurodegenerative DiseasesBonnGermany
| | - Manuel Mittag
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative DiseasesBonnGermany
| | - Martin Fuhrmann
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative DiseasesBonnGermany
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11
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Halbgebauer S, Steinacker P, Hengge S, Oeckl P, Abu Rumeileh S, Anderl-Straub S, Lombardi J, Von Arnim CAF, Giese A, Ludolph AC, Otto M. CSF levels of SNAP-25 are increased early in Creutzfeldt-Jakob and Alzheimer's disease. J Neurol Neurosurg Psychiatry 2022; 93:jnnp-2021-328646. [PMID: 35995553 DOI: 10.1136/jnnp-2021-328646] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 02/22/2022] [Indexed: 01/15/2023]
Abstract
BACKGROUND Synaptosomal-associated protein 25 (SNAP-25) in cerebrospinal fluid (CSF) is an emerging synaptic biomarker for the early diagnosis of Alzheimer's disease (AD). However, comprehensive studies investigating the marker in Creutzfeldt-Jakob disease (CJD) and in the differential diagnosis of neurodegenerative diseases are still lacking. METHODS We developed a novel, sensitive ELISA for the measurement of SNAP-25 in CSF. In total, we analysed 316 patients from 6 diagnostic groups comprising patients with AD (n=96), CJD (n=55), Parkinson's disease spectrum (n=41), frontotemporal lobar degeneration (n=25) and amyotrophic lateral sclerosis (n=24) and non-neurodegenerative control patients (n=75). Using receiver operating characteristic curve analysis, we analysed the differential diagnostic potential and compared the results with core AD biomarkers. RESULTS SNAP-25 CSF concentrations were elevated in AD and CJD (p<0.0001) but not in the other neurodegenerative diseases. Increased levels were observed already at early AD and CJD stages (p<0.0001). In CJD, SNAP-25 levels correlated negatively with survival time (r=-0.33 (95% CI -0.57 to -0.04, p=0.02). For the discrimination of AD from all other diseases except CJD, we observed a good diagnostic performance for CSF SNAP-25 (area under the curve (AUC) 0.85) which was further improved by applying the ratio with CSF amyloid-β 1-42 (AUC 0.95). For CJD, we could demonstrate a strong differential diagnostic potential against all other groups including AD (AUC 0.97). CONCLUSION Using the novel established CSF SNAP-25 ELISA, we here demonstrate the applicability of SNAP-25 as an early synaptic biomarker for both AD and CJD with a possible prognostic value in patients with CJD.
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Affiliation(s)
| | - Petra Steinacker
- Department of Neurology, University of Ulm, Ulm, Germany
- Neurology, Martin-Luther-Universitat Halle-Wittenberg, Halle, Germany
| | - Sophie Hengge
- Department of Neurology, University of Ulm, Ulm, Germany
| | - Patrick Oeckl
- Department of Neurology, University of Ulm, Ulm, Germany
- German Center for Neurodegenerative Diseases, Ulm, Germany
| | - Samir Abu Rumeileh
- Department of Neurology, University of Ulm, Ulm, Germany
- Neurology, Martin-Luther-Universitat Halle-Wittenberg, Halle, Germany
| | | | | | - Christine A F Von Arnim
- Department of Neurology, University of Ulm, Ulm, Germany
- Department of Geriatrics, University Medical Center Göttingen, Goettingen, Germany
| | - Armin Giese
- Center for Neuropathology and Prion Research, Ludwig-Maximilians-University, Munich, Germany
| | - Albert C Ludolph
- Department of Neurology, University of Ulm, Ulm, Germany
- German Center for Neurodegenerative Diseases, Ulm, Germany
| | - Markus Otto
- Department of Neurology, University of Ulm, Ulm, Germany
- Neurology, Martin-Luther-Universitat Halle-Wittenberg, Halle, Germany
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12
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Blume T, Filser S, Sgobio C, Peters F, Neumann U, Shimshek D, Saito T, Saido TC, Brendel M, Herms J. β-secretase inhibition prevents structural spine plasticity deficits in AppNL-G-F mice. Front Aging Neurosci 2022; 14:909586. [PMID: 35936777 PMCID: PMC9354544 DOI: 10.3389/fnagi.2022.909586] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 06/29/2022] [Indexed: 11/23/2022] Open
Abstract
All clinical BACE1-inhibitor trials for the treatment of Alzheimer's Disease (AD) have failed due to insufficient efficacy or side effects like worsening of cognitive symptoms. However, the scientific evidence to date suggests that BACE1-inhibition could be an effective preventative measure if applied prior to the accumulation of amyloid-beta (Aβ)-peptide and resultant impairment of synaptic function. Preclinical studies have associated BACE1-inhibition-induced cognitive deficits with decreased dendritic spine density. Therefore, we investigated dose-dependent effects of BACE1-inhibition on hippocampal dendritic spine dynamics in an APP knock-in mouse line for the first time. We conducted in vivo two-photon microscopy in the stratum oriens layer of hippocampal CA1 neurons in 3.5-month-old AppNL-G-FGFP-M mice over 6 weeks to monitor the effect of potential preventive treatment with a high and low dose of the BACE1-inhibitor NB-360 on dendritic spine dynamics. Structural spine plasticity was severely impaired in untreated AppNL-G-FGFP-M mice, although spines were not yet showing signs of degeneration. Prolonged high-dose BACE1-inhibition significantly enhanced spine formation, improving spine dynamics in the AD mouse model. We conclude that in an early AD stage characterized by low Aβ-accumulation and no irreversible spine loss, BACE1-inhibition could hold the progressive synapse loss and cognitive decline by improving structural spine dynamics.
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Affiliation(s)
- Tanja Blume
- German Center for Neurodegenerative Diseases, Munich, Germany
- Center for Neuropathology and Prion Research, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Severin Filser
- Institute for Stroke and Dementia Research, University Hospital, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Carmelo Sgobio
- German Center for Neurodegenerative Diseases, Munich, Germany
- Center for Neuropathology and Prion Research, Ludwig-Maximilians-University of Munich, Munich, Germany
| | | | - Ulf Neumann
- Department of Neuroscience, Novartis Institutes for BioMedical Research, Basel, Switzerland
| | - Derya Shimshek
- Department of Neuroscience, Novartis Institutes for BioMedical Research, Basel, Switzerland
| | - Takashi Saito
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, Saitama, Japan
- Department of Neurocognitive Science, Institute of Brain Science, Nagoya City University Graduate School of Medical Sciences, Aichi, Japan
| | - Takaomi C. Saido
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, Saitama, Japan
| | - Matthias Brendel
- Munich Cluster for Systems Neurology, Munich, Germany
- Department of Nuclear Medicine, University Hospital of Munich, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Jochen Herms
- German Center for Neurodegenerative Diseases, Munich, Germany
- Center for Neuropathology and Prion Research, Ludwig-Maximilians-University of Munich, Munich, Germany
- Munich Cluster for Systems Neurology, Munich, Germany
- *Correspondence: Jochen Herms
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13
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Slota JA, Medina SJ, Frost KL, Booth SA. Neurons and Astrocytes Elicit Brain Region Specific Transcriptional Responses to Prion Disease in the Murine CA1 and Thalamus. Front Neurosci 2022; 16:918811. [PMID: 35651626 PMCID: PMC9149297 DOI: 10.3389/fnins.2022.918811] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 04/29/2022] [Indexed: 01/14/2023] Open
Abstract
Progressive dysfunction and loss of neurons ultimately culminates in the symptoms and eventual fatality of prion disease, yet the pathways and mechanisms that lead to neuronal degeneration remain elusive. Here, we used RNAseq to profile transcriptional changes in microdissected CA1 and thalamus brain tissues from prion infected mice. Numerous transcripts were altered during clinical disease, whereas very few transcripts were reliably altered at pre-clinical time points. Prion altered transcripts were assigned to broadly defined brain cell types and we noted a strong transcriptional signature that was affiliated with reactive microglia and astrocytes. While very few neuronal transcripts were common between the CA1 and thalamus, we described transcriptional changes in both regions that were related to synaptic dysfunction. Using transcriptional profiling to compare how different neuronal populations respond during prion disease may help decipher mechanisms that lead to neuronal demise and should be investigated with greater detail.
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Affiliation(s)
- Jessy A. Slota
- One Health Division, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB, Canada
- Department of Medical Microbiology and Infectious Diseases, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Sarah J. Medina
- One Health Division, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB, Canada
| | - Kathy L. Frost
- One Health Division, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB, Canada
| | - Stephanie A. Booth
- One Health Division, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB, Canada
- Department of Medical Microbiology and Infectious Diseases, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
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14
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Shi Y, Cui M, Ochs K, Brendel M, Strübing FL, Briel N, Eckenweber F, Zou C, Banati RB, Liu GJ, Middleton RJ, Rupprecht R, Rudolph U, Zeilhofer HU, Rammes G, Herms J, Dorostkar MM. Long-term diazepam treatment enhances microglial spine engulfment and impairs cognitive performance via the mitochondrial 18 kDa translocator protein (TSPO). Nat Neurosci 2022; 25:317-329. [PMID: 35228700 DOI: 10.1038/s41593-022-01013-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 01/14/2022] [Indexed: 01/08/2023]
Abstract
Benzodiazepines are widely administered drugs to treat anxiety and insomnia. In addition to tolerance development and abuse liability, their chronic use may cause cognitive impairment and increase the risk for dementia. However, the mechanism by which benzodiazepines might contribute to persistent cognitive decline remains unknown. Here we report that diazepam, a widely prescribed benzodiazepine, impairs the structural plasticity of dendritic spines, causing cognitive impairment in mice. Diazepam induces these deficits via the mitochondrial 18 kDa translocator protein (TSPO), rather than classical γ-aminobutyric acid type A receptors, which alters microglial morphology, and phagocytosis of synaptic material. Collectively, our findings demonstrate a mechanism by which TSPO ligands alter synaptic plasticity and, as a consequence, cause cognitive impairment.
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Affiliation(s)
- Yuan Shi
- Center for Neuropathology, Ludwig Maximilian University of Munich, Munich, Germany.,German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.,Munich Medical Research School, Ludwig Maximilian University of Munich, Munich, Germany
| | - Mochen Cui
- Center for Neuropathology, Ludwig Maximilian University of Munich, Munich, Germany.,German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Munich Medical Research School, Ludwig Maximilian University of Munich, Munich, Germany
| | - Katharina Ochs
- Center for Neuropathology, Ludwig Maximilian University of Munich, Munich, Germany.,German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Matthias Brendel
- Department of Nuclear Medicine, University Hospital of Munich, Ludwig Maximilian University of Munich, Munich, Germany
| | - Felix L Strübing
- Center for Neuropathology, Ludwig Maximilian University of Munich, Munich, Germany.,German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Nils Briel
- Center for Neuropathology, Ludwig Maximilian University of Munich, Munich, Germany.,German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Munich Medical Research School, Ludwig Maximilian University of Munich, Munich, Germany
| | - Florian Eckenweber
- Department of Nuclear Medicine, University Hospital of Munich, Ludwig Maximilian University of Munich, Munich, Germany
| | - Chengyu Zou
- Center for Neuropathology, Ludwig Maximilian University of Munich, Munich, Germany.,German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, China
| | - Richard B Banati
- Australian Nuclear Science and Technology Organisation (ANSTO), Sydney NSW, Australia.,Brain and Mind Centre, Medical Imaging Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney NSW, Australia
| | - Guo-Jun Liu
- Australian Nuclear Science and Technology Organisation (ANSTO), Sydney NSW, Australia.,Brain and Mind Centre, Medical Imaging Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney NSW, Australia
| | - Ryan J Middleton
- Australian Nuclear Science and Technology Organisation (ANSTO), Sydney NSW, Australia
| | - Rainer Rupprecht
- Department of Psychiatry and Psychotherapy, University of Regensburg, Regensburg, Germany
| | - Uwe Rudolph
- Department of Comparative Biosciences, College of Veterinary Medicine, and Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Hanns Ulrich Zeilhofer
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland.,Institute of Pharmaceutical Sciences, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland
| | - Gerhard Rammes
- Department of Anesthesiology and Intensive Care Medicine, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Jochen Herms
- Center for Neuropathology, Ludwig Maximilian University of Munich, Munich, Germany. .,German Center for Neurodegenerative Diseases (DZNE), Munich, Germany. .,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.
| | - Mario M Dorostkar
- Center for Neuropathology, Ludwig Maximilian University of Munich, Munich, Germany. .,German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.
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15
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Kushwaha R, Sinha A, Makarava N, Molesworth K, Baskakov IV. Non-cell autonomous astrocyte-mediated neuronal toxicity in prion diseases. Acta Neuropathol Commun 2021; 9:22. [PMID: 33546775 PMCID: PMC7866439 DOI: 10.1186/s40478-021-01123-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 01/14/2021] [Indexed: 02/08/2023] Open
Abstract
Under normal conditions, astrocytes perform a number of important physiological functions centered around neuronal support and synapse maintenance. In neurodegenerative diseases including Alzheimer’s, Parkinson’s and prion diseases, astrocytes acquire reactive phenotypes, which are sustained throughout the disease progression. It is not known whether in the reactive states associated with prion diseases, astrocytes lose their ability to perform physiological functions and whether the reactive states are neurotoxic or, on the contrary, neuroprotective. The current work addresses these questions by testing the effects of reactive astrocytes isolated from prion-infected C57BL/6J mice on primary neuronal cultures. We found that astrocytes isolated at the clinical stage of the disease exhibited reactive, pro-inflammatory phenotype, which also showed downregulation of genes involved in neurogenic and synaptogenic functions. In astrocyte-neuron co-cultures, astrocytes from prion-infected animals impaired neuronal growth, dendritic spine development and synapse maturation. Toward examining the role of factors secreted by reactive astrocytes, astrocyte-conditioned media was found to have detrimental effects on neuronal viability and synaptogenic functions via impairing synapse integrity, and by reducing spine size and density. Reactive microglia isolated from prion-infected animals were found to induce phenotypic changes in primary astrocytes reminiscent to those observed in prion-infected mice. In particular, astrocytes cultured with reactive microglia-conditioned media displayed hypertrophic morphology and a downregulation of genes involved in neurogenic and synaptogenic functions. In summary, the current study provided experimental support toward the non-cell autonomous mechanisms behind neurotoxicity in prion diseases and demonstrated that the astrocyte reactive phenotype associated with prion diseases is synaptotoxic.
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16
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Mazzucchi S, Palermo G, Campese N, Galgani A, Della Vecchia A, Vergallo A, Siciliano G, Ceravolo R, Hampel H, Baldacci F. The role of synaptic biomarkers in the spectrum of neurodegenerative diseases. Expert Rev Proteomics 2020; 17:543-559. [PMID: 33028119 DOI: 10.1080/14789450.2020.1831388] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
INTRODUCTION The quest for reliable fluid biomarkers tracking synaptic disruption is supported by the evidence of a tight association between synaptic density and cognitive performance in neurodegenerative diseases (NDD), especially Alzheimer's disease (AD). AREAS COVERED Neurogranin (Ng) is a post-synaptic protein largely expressed in neurons involved in the memory networks. Currently, Ng measured in CSF is the most promising synaptic biomarker. Several studies show Ng elevated in AD dementia with a hippocampal phenotype as well as in MCI individuals who progress to AD. Ng concentrations are also increased in Creutzfeldt Jacob Disease where widespread and massive synaptic disintegration takes place. Ng does not discriminate Parkinson's disease from atypical parkinsonisms, nor is it altered in Huntington disease. CSF synaptosomal-associated protein 25 (SNAP-25) and synaptotagmin-1 (SYT-1) are emerging candidates. EXPERT OPINION CSF Ng revealed a role as a diagnostic and prognostic biomarker in NDD. Ng increase seems to be very specific for typical AD phenotype, probably for a prevalent hippocampal involvement. Synaptic biomarkers may serve different context-of-use in AD and other NDD including prognosis, diagnosis, and tracking synaptic damage - a critical pathophysiological mechanism in NDD - thus representing reliable tools for a precision medicine-oriented approach to NDD.
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Affiliation(s)
- Sonia Mazzucchi
- Department of Clinical and Experimental Medicine, University of Pisa , Pisa, Italy
| | - Giovanni Palermo
- Department of Clinical and Experimental Medicine, University of Pisa , Pisa, Italy
| | - Nicole Campese
- Department of Clinical and Experimental Medicine, University of Pisa , Pisa, Italy
| | - Alessandro Galgani
- Department of Clinical and Experimental Medicine, University of Pisa , Pisa, Italy
| | | | - Andrea Vergallo
- Sorbonne University, GRC N° 21, Alzheimer Precision Medicine (APM), AP-HP, Pitié-Salpêtrière Hospital, Boulevard de L'hôpital , Paris, France.,Brain & Spine Institute (ICM), INSERM U1127 , Paris, France.,Department of Neurology, Institute of Memory and Alzheimer's Disease (IM2A), Pitié-Salpêtrière Hospital, AP-HP , Paris, France
| | - Gabriele Siciliano
- Department of Clinical and Experimental Medicine, University of Pisa , Pisa, Italy
| | - Roberto Ceravolo
- Department of Clinical and Experimental Medicine, University of Pisa , Pisa, Italy
| | - Harald Hampel
- Sorbonne University, GRC N° 21, Alzheimer Precision Medicine (APM), AP-HP, Pitié-Salpêtrière Hospital, Boulevard de L'hôpital , Paris, France
| | - Filippo Baldacci
- Department of Clinical and Experimental Medicine, University of Pisa , Pisa, Italy.,Sorbonne University, GRC N° 21, Alzheimer Precision Medicine (APM), AP-HP, Pitié-Salpêtrière Hospital, Boulevard de L'hôpital , Paris, France
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17
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Cangalaya C, Stoyanov S, Fischer KD, Dityatev A. Light-induced engagement of microglia to focally remodel synapses in the adult brain. eLife 2020; 9:e58435. [PMID: 32808923 PMCID: PMC7470825 DOI: 10.7554/elife.58435] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 08/18/2020] [Indexed: 12/18/2022] Open
Abstract
Microglia continuously monitor synapses, but active synaptic remodeling by microglia in mature healthy brains is rarely directly observed. We performed targeted photoablation of single synapses in mature transgenic mice expressing fluorescent labels in neurons and microglia. The photodamage focally increased the duration of microglia-neuron contacts, and dramatically exacerbated both the turnover of dendritic spines and presynaptic boutons as well as the generation of new filopodia originating from spine heads or boutons. The results of microglia depletion confirmed that elevated spine turnover and the generation of presynaptic filopodia are microglia-dependent processes.
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Affiliation(s)
- Carla Cangalaya
- ESF International Graduate School on Analysis, Imaging and Modelling of Neuronal and Inflammatory ProcessesMagdeburgGermany
- Institut für Biochemie und Zellbiologie, Otto-von-Guericke-University, Medical FacultyMagdeburgGermany
- Molecular Neuroplasticity, German Center for Neurodegenerative Diseases (DZNE)MagdeburgGermany
| | - Stoyan Stoyanov
- Molecular Neuroplasticity, German Center for Neurodegenerative Diseases (DZNE)MagdeburgGermany
| | - Klaus-Dieter Fischer
- Institut für Biochemie und Zellbiologie, Otto-von-Guericke-University, Medical FacultyMagdeburgGermany
| | - Alexander Dityatev
- Molecular Neuroplasticity, German Center for Neurodegenerative Diseases (DZNE)MagdeburgGermany
- Medical Faculty, Otto-von-Guericke UniversityMagdeburgGermany
- Center for Behavioral Brain Sciences (CBBS)MagdeburgGermany
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18
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Mutant prion proteins increase calcium permeability of AMPA receptors, exacerbating excitotoxicity. PLoS Pathog 2020; 16:e1008654. [PMID: 32673372 PMCID: PMC7365390 DOI: 10.1371/journal.ppat.1008654] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2020] [Accepted: 05/26/2020] [Indexed: 01/26/2023] Open
Abstract
Prion protein (PrP) mutations are linked to genetic prion diseases, a class of phenotypically heterogeneous neurodegenerative disorders with invariably fatal outcome. How mutant PrP triggers neurodegeneration is not known. Synaptic dysfunction precedes neuronal loss but it is not clear whether, and through which mechanisms, disruption of synaptic activity ultimately leads to neuronal death. Here we show that mutant PrP impairs the secretory trafficking of AMPA receptors (AMPARs). Specifically, intracellular retention of the GluA2 subunit results in synaptic exposure of GluA2-lacking, calcium-permeable AMPARs, leading to increased calcium permeability and enhanced sensitivity to excitotoxic cell death. Mutant PrPs linked to different genetic prion diseases affect AMPAR trafficking and function in different ways. Our findings identify AMPARs as pathogenic targets in genetic prion diseases, and support the involvement of excitotoxicity in neurodegeneration. They also suggest a mechanistic explanation for how different mutant PrPs may cause distinct disease phenotypes. Genetic prion diseases are degenerative brain disorders caused by mutations in the gene encoding the prion protein (PrP). Different PrP mutations cause different diseases, including Creutzfeldt-Jakob disease, fatal familial insomnia and Gerstmann-Sträussler-Scheinker syndrome. How mutant PrP causes neuronal death and how different mutants encode distinct disease phenotypes is not known. Here we show that mutant PrP alters the subunit composition of glutamate AMPA receptors, promoting cell surface exposure of GluA2-lacking, calcium-permeable receptors, ultimately increasing neuronal vulnerability to excitotoxic cell death. We also demonstrate that the underlying molecular mechanism is the formation of a GluA2 subunit-PrP complex which is retained in the neuronal secretory pathway. PrP mutants associated with clinically different genetic prion diseases have distinct effects on GluA2 trafficking, depending on their tendency to misfold and aggregate in different intracellular organelles, indicating a possible contribution of this mechanism to the disease phenotype.
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19
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Peters F, Salihoglu H, Pratsch K, Herzog E, Pigoni M, Sgobio C, Lichtenthaler SF, Neumann U, Herms J. Tau deletion reduces plaque-associated BACE1 accumulation and decelerates plaque formation in a mouse model of Alzheimer's disease. EMBO J 2019; 38:e102345. [PMID: 31701556 PMCID: PMC6885735 DOI: 10.15252/embj.2019102345] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 09/29/2019] [Accepted: 10/08/2019] [Indexed: 01/24/2023] Open
Abstract
In Alzheimer's disease, BACE1 protease initiates the amyloidogenic processing of amyloid precursor protein (APP) that eventually results in synthesis of β-amyloid (Aβ) peptide. Aβ deposition in turn causes accumulation of BACE1 in plaque-associated dystrophic neurites, thereby potentiating progressive Aβ deposition once initiated. Since systemic pharmacological BACE inhibition causes adverse effects in humans, it is important to identify strategies that specifically normalize overt BACE1 activity around plaques. The microtubule-associated protein tau regulates axonal transport of proteins, and tau deletion rescues Aβ-induced transport deficits in vitro. In the current study, long-term in vivo two-photon microscopy and immunohistochemistry were performed in tau-deficient APPPS1 mice. Tau deletion reduced plaque-associated axonal pathology and BACE1 accumulation without affecting physiological BACE1 expression distant from plaques. Thereby, tau deletion effectively decelerated formation of new plaques and reduced plaque compactness. The data revealed that tau reinforces Aβ deposition, presumably by contributing to accumulation of BACE1 in plaque-associated dystrophies. Targeting tau-dependent mechanisms could become a suitable strategy to specifically reduce overt BACE1 activity around plaques, thereby avoiding adverse effects of systemic BACE inhibition.
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Affiliation(s)
- Finn Peters
- German Center for Neurodegenerative Diseases (DZNE)MunichGermany
- Munich Cluster of Systems Neurology (SyNergy)MunichGermany
| | - Hazal Salihoglu
- German Center for Neurodegenerative Diseases (DZNE)MunichGermany
- Munich Cluster of Systems Neurology (SyNergy)MunichGermany
| | - Katrin Pratsch
- German Center for Neurodegenerative Diseases (DZNE)MunichGermany
| | - Etienne Herzog
- IINS, UMR 5297Université BordeauxBordeauxFrance
- CNRS, IINS, UMR 5297BordeauxFrance
| | - Martina Pigoni
- German Center for Neurodegenerative Diseases (DZNE)MunichGermany
- Munich Cluster of Systems Neurology (SyNergy)MunichGermany
| | - Carmelo Sgobio
- German Center for Neurodegenerative Diseases (DZNE)MunichGermany
| | - Stefan F Lichtenthaler
- German Center for Neurodegenerative Diseases (DZNE)MunichGermany
- Munich Cluster of Systems Neurology (SyNergy)MunichGermany
- NeuroproteomicsSchool of MedicineKlinikum rechts der Isar and Institute for Advanced StudyTechnical University of MunichMunichGermany
| | - Ulf Neumann
- NeuroscienceNovartis Institutes for BioMedical Research (NIBR)BaselSwitzerland
| | - Jochen Herms
- German Center for Neurodegenerative Diseases (DZNE)MunichGermany
- Munich Cluster of Systems Neurology (SyNergy)MunichGermany
- Center for Neuropathology and Prion ResearchLudwig‐Maximilians UniversityMunichGermany
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20
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Vadakkan KI. From cells to sensations: A window to the physics of mind. Phys Life Rev 2019; 31:44-78. [PMID: 31759872 DOI: 10.1016/j.plrev.2019.10.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 09/06/2019] [Accepted: 10/16/2019] [Indexed: 12/14/2022]
Abstract
Principles of methods for studying particles and fields that cannot be sensed by third-person observers by routine methods can be used to understand the physics of first-person properties of mind. Accordingly, whenever a system exhibits disparate features at multiple levels, unique combination of constraints offered by them direct us towards a solution that will be the first principle of that system. Using this method, it was possible to arrive at a third-person observable solution-point of brain-mind interface. Examination of this location identified a set of unique features that can allow an associatively learned (cue) stimulus to spark hallucinations that form units of first-person internal (inner) sensations reminiscent of stimuli from the associatively learned second item in timescales of milliseconds. It allows us to peep into a virtual space of mind where different modifications and integrations of units of internal sensations generate their different net conformations ranging from perception to an inner sense of hidden relationships that form a hypothesis. Since sparking of inner sensations of the late arriving (when far away) or non-arriving (when hidden) features of items started providing survival advantage, the focus of evolution might have been to optimize this property. Hence, the circuity that generates it can be considered as the primary circuitry of the system. The solution provides several testable predictions. By taking readers through the process of deriving the solution and by explaining how it interconnects disparate findings, it is hoped that the factors determining the physics of mind will become evident.
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Affiliation(s)
- Kunjumon I Vadakkan
- Division of Neurology, Department of Medicine, QEII Health Sciences Centre, 1796 Summer Street, Dalhousie University, Halifax, NS, B3H 3A7, Canada.
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21
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Blennow K, Diaz-Lucena D, Zetterberg H, Villar-Pique A, Karch A, Vidal E, Hermann P, Schmitz M, Ferrer Abizanda I, Zerr I, Llorens F. CSF neurogranin as a neuronal damage marker in CJD: a comparative study with AD. J Neurol Neurosurg Psychiatry 2019; 90:846-853. [PMID: 31097472 DOI: 10.1136/jnnp-2018-320155] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 03/22/2019] [Accepted: 04/07/2019] [Indexed: 11/03/2022]
Abstract
OBJECTIVE To investigate whether cerebrospinal fluid (CSF) neurogranin concentrations are altered in sporadic Creutzfeldt-Jakob disease (CJD), comparatively with Alzheimer's disease (AD), and associated with neuronal degeneration in brain tissue. METHODS CSF neurogranin, total tau, neurofilament light (NFL) and 14-3-3 protein were measured in neurological controls (NCs, n=64), AD (n=46) and CJD (n=81). The accuracy of neurogranin discriminating the three diagnostic groups was evaluated. Correlations between neurogranin and neurodegeneration biomarkers, demographic, genetic and clinical data were assessed. Additionally, neurogranin expression in postmortem brain tissue was studied. RESULTS Compared with NC, CSF neurogranin concentrations were increased in CJD (4.75 times of NC; p<0.001, area under curve (AUC), 0.96 (95% CI 0.93 to 0.99) and AD (1.94 times of NC; p<0.01, AUC 0.73, 95% CI 0.62 to 0.82), and were able to differentiate CJD from AD (p<0.001, AUC 0.85, 95% CI 0.78 to 0.92). CSF tau was increased in CJD (41 times of NC) and in AD (3.1 times of NC), both at p<0.001. In CJD, neurogranin positively correlated with tau (r=0.55, p<0.001) and was higher in 14-3-3-positivity (p<0.05), but showed no association with NFL (r=0.08, p=0.46). CJD-MM1/MV1 cases displayed higher neurogranin levels than VV2 cases. Neurogranin was increased at early CJD disease stages and was a good prognostic marker of survival time in CJD. In brain tissue, neurogranin was detected in the cytoplasm, membrane and postsynaptic density fractions of neurons, with reduced levels in AD, and more significantly in CJD, where they correlated with synaptic and axonal markers. CONCLUSIONS Neurogranin is a new biomarker of prion pathogenesis with diagnostic and prognostic abilities, which reflects the degree of neuronal damage in brain tissue in a CJD subtype manner.
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Affiliation(s)
- Kaj Blennow
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Mölndal, Sweden.,Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
| | - Daniela Diaz-Lucena
- Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), Institute Carlos III, Ministry of Health, L'Hospilatet del Llobregat, Barcelona, Spain
| | - Henrik Zetterberg
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Mölndal, Sweden.,Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden.,Department of Neurodegenerative Disease, UCL Institute of Neurology, London, United Kingdom.,UK Dementia Research Institute, London, United Kingdom
| | - Anna Villar-Pique
- Department of Neurology, University Medical School, Göttingen, Germany
| | - Andre Karch
- Department of Epidemiology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Enric Vidal
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, Bellaterra, Catalonia, Spain
| | - Peter Hermann
- Department of Neurology, University Medical School, Göttingen, Germany
| | - Matthias Schmitz
- Department of Neurology, University Medical School, Göttingen, Germany.,German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany
| | - Isidro Ferrer Abizanda
- Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), Institute Carlos III, Ministry of Health, L'Hospilatet del Llobregat, Barcelona, Spain.,Institute of Neuropathology, Bellvitge Biomedical Research Institutue (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain
| | - Inga Zerr
- Department of Neurology, University Medical School, Göttingen, Germany.,German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany
| | - Franc Llorens
- Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), Institute Carlos III, Ministry of Health, L'Hospilatet del Llobregat, Barcelona, Spain .,Department of Neurology, University Medical School, Göttingen, Germany.,Institute of Neuropathology, Bellvitge Biomedical Research Institutue (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain
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22
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Mercer RC, Harris DA. Identification of anti-prion drugs and targets using toxicity-based assays. Curr Opin Pharmacol 2019; 44:20-27. [PMID: 30684854 DOI: 10.1016/j.coph.2018.12.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 12/18/2018] [Accepted: 12/20/2018] [Indexed: 01/24/2023]
Abstract
Prion diseases are untreatable and invariably fatal, making the discovery of effective therapeutic interventions a priority. Most candidate molecules have been discovered based on their ability to reduce the levels of PrPSc, the infectious form of the prion protein, in cultured neuroblastoma cells. We have employed an alternative assay, based on an abnormal cellular phenotype associated with a mutant prion protein, to discover a novel class of anti-prion compounds, the phenethyl piperidines. Using an assay that monitors the acute toxic effects of PrPSc on the synapses of cultured hippocampal neurons, we have identified p38 MAPK as a druggable pharmacological target that is already being pursued for the treatment of other human diseases. Organotypic brain slices, which can propagate prions and mimic several neuropathological features of the disease, have also been used to test inhibitory compounds. An effective anti-prion regimen will involve synergistic combination of drugs acting at multiple steps of the pathogenic process, resulting not only in reduction in prion levels but also suppression of neurotoxic signaling.
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Affiliation(s)
- Robert Cc Mercer
- Boston University School of Medicine, Boston, MA 02118, United States
| | - David A Harris
- Boston University School of Medicine, Boston, MA 02118, United States.
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23
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Montagna E, Crux S, Luckner M, Herber J, Colombo AV, Marinković P, Tahirovic S, Lichtenthaler SF, Wanner G, Müller UC, Sgobio C, Herms J. In vivo
Ca
2+
imaging of astrocytic microdomains reveals a critical role of the amyloid precursor protein for mitochondria. Glia 2019; 67:985-998. [DOI: 10.1002/glia.23584] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 12/17/2018] [Accepted: 12/20/2018] [Indexed: 01/04/2023]
Affiliation(s)
- Elena Montagna
- Division of Translational Brain Research, German Center for Neurodegenerative Diseases (DZNE) Munich Germany
- Division of Translational Brain Research, Center for Neuropathology and Prion ResearchLudwig–Maximilians University Munich Germany
- Munich Cluster of Systems Neurology (SyNergy)Ludwig‐Maximilians University Munich Germany
| | - Sophie Crux
- Division of Translational Brain Research, German Center for Neurodegenerative Diseases (DZNE) Munich Germany
- Division of Translational Brain Research, Center for Neuropathology and Prion ResearchLudwig–Maximilians University Munich Germany
- Munich Cluster of Systems Neurology (SyNergy)Ludwig‐Maximilians University Munich Germany
| | - Manja Luckner
- Department Biology I, BiocenterLudwig‐Maximilians University Munich Martinsried Germany
| | - Julia Herber
- Division of Translational Brain Research, German Center for Neurodegenerative Diseases (DZNE) Munich Germany
- Neuroproteomics, School of Medicine, Klinikum rechts der Isar and Institute for Advanced StudyTechnische Universität München Munich Germany
| | - Alessio V. Colombo
- Division of Translational Brain Research, German Center for Neurodegenerative Diseases (DZNE) Munich Germany
| | - Petar Marinković
- Division of Translational Brain Research, German Center for Neurodegenerative Diseases (DZNE) Munich Germany
| | - Sabina Tahirovic
- Division of Translational Brain Research, German Center for Neurodegenerative Diseases (DZNE) Munich Germany
| | - Stefan F. Lichtenthaler
- Division of Translational Brain Research, German Center for Neurodegenerative Diseases (DZNE) Munich Germany
- Munich Cluster of Systems Neurology (SyNergy)Ludwig‐Maximilians University Munich Germany
- Neuroproteomics, School of Medicine, Klinikum rechts der Isar and Institute for Advanced StudyTechnische Universität München Munich Germany
| | - Gerhard Wanner
- Department Biology I, BiocenterLudwig‐Maximilians University Munich Martinsried Germany
| | - Ulrike C. Müller
- Department of Functional Genomics, Institute of Pharmacy and Molecular BiotechnologyHeidelberg University Heidelberg Germany
| | - Carmelo Sgobio
- Division of Translational Brain Research, German Center for Neurodegenerative Diseases (DZNE) Munich Germany
| | - Jochen Herms
- Division of Translational Brain Research, German Center for Neurodegenerative Diseases (DZNE) Munich Germany
- Division of Translational Brain Research, Center for Neuropathology and Prion ResearchLudwig–Maximilians University Munich Germany
- Munich Cluster of Systems Neurology (SyNergy)Ludwig‐Maximilians University Munich Germany
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24
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Le NTT, Wu B, Harris DA. Prion neurotoxicity. Brain Pathol 2019; 29:263-277. [PMID: 30588688 DOI: 10.1111/bpa.12694] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 11/28/2018] [Indexed: 01/04/2023] Open
Abstract
Although the mechanisms underlying prion propagation and infectivity are now well established, the processes accounting for prion toxicity and pathogenesis have remained mysterious. These processes are of enormous clinical relevance as they hold the key to identification of new molecular targets for therapeutic intervention. In this review, we will discuss two broad areas of investigation relevant to understanding prion neurotoxicity. The first is the use of in vitro experimental systems that model key events in prion pathogenesis. In this context, we will describe a hippocampal neuronal culture system we developed that reproduces the earliest pathological alterations in synaptic morphology and function in response to PrPSc . This system has allowed us to define a core synaptotoxic signaling pathway involving the activation of NMDA and AMPA receptors, stimulation of p38 MAPK phosphorylation and collapse of the actin cytoskeleton in dendritic spines. The second area concerns a striking and unexpected phenomenon in which certain structural manipulations of the PrPC molecule itself, including introduction of N-terminal deletion mutations or binding of antibodies to C-terminal epitopes, unleash powerful toxic effects in cultured cells and transgenic mice. We will describe our studies of this phenomenon, which led to the recognition that it is related to the induction of large, abnormal ionic currents by the structurally altered PrP molecules. Our results suggest a model in which the flexible N-terminal domain of PrPC serves as a toxic effector which is regulated by intramolecular interactions with the globular C-terminal domain. Taken together, these two areas of study have provided important clues to underlying cellular and molecular mechanisms of prion neurotoxicity. Nevertheless, much remains to be done on this next frontier of prion science.
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Affiliation(s)
- Nhat T T Le
- Department of Biochemistry, Boston University School of Medicine, Boston, MA
| | - Bei Wu
- Department of Biochemistry, Boston University School of Medicine, Boston, MA
| | - David A Harris
- Department of Biochemistry, Boston University School of Medicine, Boston, MA
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25
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Ziegler-Waldkirch S, Meyer-Luehmann M. The Role of Glial Cells and Synapse Loss in Mouse Models of Alzheimer's Disease. Front Cell Neurosci 2018; 12:473. [PMID: 30618627 PMCID: PMC6297249 DOI: 10.3389/fncel.2018.00473] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 11/20/2018] [Indexed: 11/13/2022] Open
Abstract
Synapse loss has detrimental effects on cellular communication, leading to network disruptions within the central nervous system (CNS) such as in Alzheimer’s disease (AD). AD is characterized by a progressive decline of memory function, cognition, neuronal and synapse loss. The two main neuropathological hallmarks are amyloid-β (Aβ) plaques and neurofibrillary tangles. In the brain of AD patients and in mouse models of AD several morphological and functional changes, such as microgliosis and astrogliosis around Aβ plaques, as well as dendritic and synaptic alterations, are associated with these lesions. In this review article, we will summarize the current literature on synapse loss in mouse models of AD and discuss current and prospective treatments for AD.
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Affiliation(s)
- Stephanie Ziegler-Waldkirch
- Department of Neurology, Medical Center-University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Melanie Meyer-Luehmann
- Department of Neurology, Medical Center-University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
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26
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Fang C, Wu B, Le NTT, Imberdis T, Mercer RCC, Harris DA. Prions activate a p38 MAPK synaptotoxic signaling pathway. PLoS Pathog 2018; 14:e1007283. [PMID: 30235355 PMCID: PMC6147624 DOI: 10.1371/journal.ppat.1007283] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 08/15/2018] [Indexed: 11/19/2022] Open
Abstract
Synaptic degeneration is one of the earliest pathological correlates of prion disease, and it is a major determinant of the progression of clinical symptoms. However, the cellular and molecular mechanisms underlying prion synaptotoxicity are poorly understood. Previously, we described an experimental system in which treatment of cultured hippocampal neurons with purified PrPSc, the infectious form of the prion protein, induces rapid retraction of dendritic spines, an effect that is entirely dependent on expression of endogenous PrPC by the target neurons. Here, we use this system to dissect pharmacologically the underlying cellular and molecular mechanisms. We show that PrPSc initiates a stepwise synaptotoxic signaling cascade that includes activation of NMDA receptors, calcium influx, stimulation of p38 MAPK and several downstream kinases, and collapse of the actin cytoskeleton within dendritic spines. Synaptic degeneration is restricted to excitatory synapses, spares presynaptic structures, and results in decrements in functional synaptic transmission. Pharmacological inhibition of any one of the steps in the signaling cascade, as well as expression of a dominant-negative form of p38 MAPK, block PrPSc-induced spine degeneration. Moreover, p38 MAPK inhibitors actually reverse the degenerative process after it has already begun. We also show that, while PrPC mediates the synaptotoxic effects of both PrPSc and the Alzheimer’s Aβ peptide in this system, the two species activate distinct signaling pathways. Taken together, our results provide powerful insights into the biology of prion neurotoxicity, they identify new, druggable therapeutic targets, and they allow comparison of prion synaptotoxic pathways with those involved in other neurodegenerative diseases. Prion diseases are a group of fatal neurodegenerative disorders that includes Creutzfeldt-Jakob disease and kuru in humans, and bovine spongiform encephalopathy in cattle. The infectious agent, or prion, that transmits these diseases is a naked protein molecule, the prion protein (PrP), which is an altered form of a normal, cellular protein. Although a great deal is known about how prions propagate themselves and transmit infection, the process by which they actually cause neurons to degenerate has remained mysterious. Here, we have used a specialized neuronal culture system to dissect the cellular and molecular mechanisms by which prions damage synapses, the structures that connect nerve cells and that play a crucial role in learning, memory, and neurological disease. Our results define a stepwise molecular pathway underlying prion synaptic toxicity, which involves activation of glutamate neurotransmitter receptors, influx of calcium ions into the neuron, and stimulation of specific mitogen-activated protein kinases, which attach phosphate groups to proteins to regulate their activity. We demonstrate that specific drugs, as well as a dominant-negative kinase mutant, block these steps and thereby prevent the synaptic degeneration produced by prions. Our results provide new insights into the pathogenesis of prion diseases, they uncover new drug targets for treating these diseases, and they allow us to compare prion diseases to other, more common neurodegenerative disorders like Alzheimer’s disease.
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Affiliation(s)
- Cheng Fang
- Department of Biochemistry, Boston University School of Medicine, Boston MA, United States of America
| | - Bei Wu
- Department of Biochemistry, Boston University School of Medicine, Boston MA, United States of America
| | - Nhat T. T. Le
- Department of Biochemistry, Boston University School of Medicine, Boston MA, United States of America
| | - Thibaut Imberdis
- Department of Biochemistry, Boston University School of Medicine, Boston MA, United States of America
| | - Robert C. C. Mercer
- Department of Biochemistry, Boston University School of Medicine, Boston MA, United States of America
| | - David A. Harris
- Department of Biochemistry, Boston University School of Medicine, Boston MA, United States of America
- * E-mail:
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27
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Prion acute synaptotoxicity is largely driven by protease-resistant PrPSc species. PLoS Pathog 2018; 14:e1007214. [PMID: 30089152 PMCID: PMC6101418 DOI: 10.1371/journal.ppat.1007214] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 08/20/2018] [Accepted: 07/12/2018] [Indexed: 01/09/2023] Open
Abstract
Although misfolding of normal prion protein (PrPC) into abnormal conformers (PrPSc) is critical for prion disease pathogenesis our current understanding of the underlying molecular pathophysiology is rudimentary. Exploiting an electrophysiology paradigm, herein we report that at least modestly proteinase K (PK)-resistant PrPSc (PrPres) species are acutely synaptotoxic. Brief exposure to ex vivo PrPSc from two mouse-adapted prion strains (M1000 and MU02) prepared as crude brain homogenates (cM1000 and cMU02) and cell lysates from chronically M1000-infected RK13 cells (MoRK13-Inf) caused significant impairment of hippocampal CA1 region long-term potentiation (LTP), with the LTP disruption approximating that reported during the evolution of murine prion disease. Proof of PrPSc (especially PrPres) species as the synaptotoxic agent was demonstrated by: significant rescue of LTP following selective immuno-depletion of total PrP from cM1000 (dM1000); modestly PK-treated cM1000 (PK+M1000) retaining full synaptotoxicity; and restoration of the LTP impairment when employing reconstituted, PK-eluted, immuno-precipitated M1000 preparations (PK+IP-M1000). Additional detailed electrophysiological analyses exemplified by impairment of post-tetanic potentiation (PTP) suggest possible heightened pre-synaptic vulnerability to the acute synaptotoxicity. This dysfunction correlated with cumulative insufficiency of replenishment of the readily releasable pool (RRP) of vesicles during repeated high-frequency stimulation utilised for induction of LTP. Broadly comparable results with LTP and PTP impairment were obtained utilizing hippocampal slices from PrPC knockout (PrPo/o) mice, with cM1000 serial dilution assessments revealing similar sensitivity of PrPo/o and wild type (WT) slices. Size fractionation chromatography demonstrated that synaptotoxic PrP correlated with PK-resistant species >100kDa, consistent with multimeric PrPSc, with levels of these species >6 ng/ml appearing sufficient to induce synaptic dysfunction. Biochemical analyses of hippocampal slices manifesting acute synaptotoxicity demonstrated reduced levels of multiple key synaptic proteins, albeit with noteworthy differences in PrPo/o slices, while such changes were absent in hippocampi demonstrating rescued LTP through treatment with dM1000. Our findings offer important new mechanistic insights into the synaptic impairment underlying prion disease, enhancing prospects for development of targeted effective therapies. Misfolding of the normal prion protein (PrPC) into disease-associated conformations (PrPSc) is the critical initiating step for prion diseases. Similar to other neurodegenerative disorders, progressive failure of brain synapses is considered a primary deleterious event underpinning prion disease evolution. Our current understanding of the underlying mechanisms associated with synaptic failure is rudimentary contributing to difficulties in developing effective treatments. Herein we report the use of an electrophysiology paradigm that allowed us to demonstrate that at least modestly proteinase K (PK)-resistant PrPSc species from two mouse-adapted prion strains (M1000 and MU02) are directly synaptotoxic causing significant acute impairment of hippocampal CA1 region long-term potentiation (LTP). Of note, the LTP disruption approximated that reported in prion animal models. Additional detailed analyses provided novel pathophysiological insights suggesting possible heightened pre-synaptic vulnerability to the acute synaptotoxicity through impairment of replenishment of the readily releasable pool of neurotransmitter vesicles, while biochemical analyses demonstrated reduced levels of multiple key pre-and post-synaptic proteins. Broadly similar acute synaptic dysfunction and dose-response susceptibility were observed in slices from mice not expressing PrPC albeit with minor but noteworthy differences in electrophysiological and biochemical findings. Our study offers important new mechanistic insights into the synaptic impairment underlying prion disease, enhancing prospects for development effective therapies.
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28
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Blume T, Filser S, Jaworska A, Blain JF, Koenig G, Moschke K, Lichtenthaler SF, Herms J. BACE1 Inhibitor MK-8931 Alters Formation but Not Stability of Dendritic Spines. Front Aging Neurosci 2018; 10:229. [PMID: 30093858 PMCID: PMC6070607 DOI: 10.3389/fnagi.2018.00229] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 07/11/2018] [Indexed: 11/23/2022] Open
Abstract
Beta-site amyloid-precursor-protein cleaving enzyme 1 (BACE1) is the rate limiting protease in the production of the amyloid-beta peptide (Aβ), which is considered to be the causative agent in the pathogenesis of Alzheimer’s Disease (AD). Therefore, the therapeutic potential of pharmacological BACE1 inhibitors is currently tested in clinical trials for AD treatment. To ensure a positive clinical outcome it is crucial to identify and evaluate adverse effects associated with BACE1 inhibition. Preclinical studies show that chronic blockade of BACE1 activity alters synaptic functions and leads to loss of dendritic spines. To assess the mechanism of synapse loss, dendritic spine dynamics of pyramidal layer V cells were monitored by in vivo two-photon microscopy in the somatosensory cortex of mice, treated with the BACE1 inhibitor MK-8931. MK-8931 treatment significantly reduced levels of Aβ40 and density of dendritic spines in the brain. However, the steady decline in dendritic spine density specifically resulted from a diminished formation of new spines and not from a loss of stable spines. Furthermore, the described effects on spine formation were transient and recovered after inhibitor withdrawal. Since MK-8931 inhibition did not completely abolish spine formation, our findings suggest that carefully dosed inhibitors might be therapeutically effective without affecting the structural integrity of excitatory synapses if given at an early disease stage.
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Affiliation(s)
- Tanja Blume
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Helmholtz-Gemeinschaft Deutscher Forschungszentren (HZ)-German Center for Neurodegenerative Diseases, Munich, Germany
| | - Severin Filser
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Helmholtz-Gemeinschaft Deutscher Forschungszentren (HZ)-German Center for Neurodegenerative Diseases, Munich, Germany
| | - Anna Jaworska
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Helmholtz-Gemeinschaft Deutscher Forschungszentren (HZ)-German Center for Neurodegenerative Diseases, Munich, Germany
| | | | | | - Katrin Moschke
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Helmholtz-Gemeinschaft Deutscher Forschungszentren (HZ)-German Center for Neurodegenerative Diseases, Munich, Germany.,Neuroproteomics, School of Medicine, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany
| | - Stefan F Lichtenthaler
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Helmholtz-Gemeinschaft Deutscher Forschungszentren (HZ)-German Center for Neurodegenerative Diseases, Munich, Germany.,Neuroproteomics, School of Medicine, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Jochen Herms
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Helmholtz-Gemeinschaft Deutscher Forschungszentren (HZ)-German Center for Neurodegenerative Diseases, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.,Zentrum für Neuropathologie und Prionforschung, Munich, Germany
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29
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Pfeiffer T, Poll S, Bancelin S, Angibaud J, Inavalli VK, Keppler K, Mittag M, Fuhrmann M, Nägerl UV. Chronic 2P-STED imaging reveals high turnover of dendritic spines in the hippocampus in vivo. eLife 2018; 7:34700. [PMID: 29932052 PMCID: PMC6014725 DOI: 10.7554/elife.34700] [Citation(s) in RCA: 109] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 06/05/2018] [Indexed: 11/13/2022] Open
Abstract
Rewiring neural circuits by the formation and elimination of synapses is thought to be a key cellular mechanism of learning and memory in the mammalian brain. Dendritic spines are the postsynaptic structural component of excitatory synapses, and their experience-dependent plasticity has been extensively studied in mouse superficial cortex using two-photon microscopy in vivo. By contrast, very little is known about spine plasticity in the hippocampus, which is the archetypical memory center of the brain, mostly because it is difficult to visualize dendritic spines in this deeply embedded structure with sufficient spatial resolution. We developed chronic 2P-STED microscopy in mouse hippocampus, using a ‘hippocampal window’ based on resection of cortical tissue and a long working distance objective for optical access. We observed a two-fold higher spine density than previous studies and measured a spine turnover of ~40% within 4 days, which depended on spine size. We thus provide direct evidence for a high level of structural rewiring of synaptic circuits and new insights into the structure-dynamics relationship of hippocampal spines. Having established chronic super-resolution microscopy in the hippocampus in vivo, our study enables longitudinal and correlative analyses of nanoscale neuroanatomical structures with genetic, molecular and behavioral experiments.
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Affiliation(s)
- Thomas Pfeiffer
- Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, Bordeaux, France.,Interdisciplinary Institute for Neuroscience, University of Bordeaux, Bordeaux, France
| | - Stefanie Poll
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Stephane Bancelin
- Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, Bordeaux, France.,Interdisciplinary Institute for Neuroscience, University of Bordeaux, Bordeaux, France
| | - Julie Angibaud
- Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, Bordeaux, France.,Interdisciplinary Institute for Neuroscience, University of Bordeaux, Bordeaux, France
| | - Vvg Krishna Inavalli
- Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, Bordeaux, France.,Interdisciplinary Institute for Neuroscience, University of Bordeaux, Bordeaux, France
| | - Kevin Keppler
- Light Microscope Facility, German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Manuel Mittag
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Martin Fuhrmann
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases, Bonn, Germany
| | - U Valentin Nägerl
- Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, Bordeaux, France.,Interdisciplinary Institute for Neuroscience, University of Bordeaux, Bordeaux, France
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30
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Peters F, Salihoglu H, Rodrigues E, Herzog E, Blume T, Filser S, Dorostkar M, Shimshek DR, Brose N, Neumann U, Herms J. BACE1 inhibition more effectively suppresses initiation than progression of β-amyloid pathology. Acta Neuropathol 2018; 135:695-710. [PMID: 29327084 PMCID: PMC5904228 DOI: 10.1007/s00401-017-1804-9] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Revised: 12/28/2017] [Accepted: 12/29/2017] [Indexed: 01/04/2023]
Abstract
BACE1 is the rate-limiting protease in the production of synaptotoxic β-amyloid (Aβ) species and hence one of the prime drug targets for potential therapy of Alzheimer's disease (AD). However, so far pharmacological BACE1 inhibition failed to rescue the cognitive decline in mild-to-moderate AD patients, which indicates that treatment at the symptomatic stage might be too late. In the current study, chronic in vivo two-photon microscopy was performed in a transgenic AD model to monitor the impact of pharmacological BACE1 inhibition on early β-amyloid pathology. The longitudinal approach allowed to assess the kinetics of individual plaques and associated presynaptic pathology, before and throughout treatment. BACE1 inhibition could not halt but slow down progressive β-amyloid deposition and associated synaptic pathology. Notably, the data revealed that the initial process of plaque formation, rather than the subsequent phase of gradual plaque growth, is most sensitive to BACE1 inhibition. This finding of particular susceptibility of plaque formation has profound implications to achieve optimal therapeutic efficacy for the prospective treatment of AD.
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Affiliation(s)
- Finn Peters
- German Center for Neurodegenerative Diseases (DZNE), Feodor-Lynen Str. 17, 81377, Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Hazal Salihoglu
- German Center for Neurodegenerative Diseases (DZNE), Feodor-Lynen Str. 17, 81377, Munich, Germany
| | - Eva Rodrigues
- German Center for Neurodegenerative Diseases (DZNE), Feodor-Lynen Str. 17, 81377, Munich, Germany
| | - Etienne Herzog
- Université Bordeaux, IINS, UMR 5297, 33000, Bordeaux, France
- CNRS, IINS, UMR 5297, 33000, Bordeaux, France
| | - Tanja Blume
- German Center for Neurodegenerative Diseases (DZNE), Feodor-Lynen Str. 17, 81377, Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Severin Filser
- German Center for Neurodegenerative Diseases (DZNE), Feodor-Lynen Str. 17, 81377, Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Mario Dorostkar
- German Center for Neurodegenerative Diseases (DZNE), Feodor-Lynen Str. 17, 81377, Munich, Germany
- Center for Neuropathology and Prion Research, Ludwig-Maximilians University, Munich, Germany
| | - Derya R Shimshek
- Neuroscience, Novartis Institutes for BioMedical Research (NIBR), Basel, Switzerland
| | - Nils Brose
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Ulf Neumann
- Neuroscience, Novartis Institutes for BioMedical Research (NIBR), Basel, Switzerland
| | - Jochen Herms
- German Center for Neurodegenerative Diseases (DZNE), Feodor-Lynen Str. 17, 81377, Munich, Germany.
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany.
- Center for Neuropathology and Prion Research, Ludwig-Maximilians University, Munich, Germany.
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Li C, Wang D, Wu W, Yang W, Ali Shah SZ, Zhao Y, Duan Y, Wang L, Zhou X, Zhao D, Yang L. DLP1-dependent mitochondrial fragmentation and redistribution mediate prion-associated mitochondrial dysfunction and neuronal death. Aging Cell 2018; 17. [PMID: 29166700 PMCID: PMC5771399 DOI: 10.1111/acel.12693] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/30/2017] [Indexed: 12/24/2022] Open
Abstract
Mitochondrial malfunction is a universal and critical step in the pathogenesis of many neurodegenerative diseases including prion diseases. Dynamin-like protein 1 (DLP1) is one of the key regulators of mitochondrial fission. In this study, we investigated the role of DLP1 in mitochondrial fragmentation and dysfunction in neurons using in vitro and in vivo prion disease models. Mitochondria became fragmented and redistributed from axons to soma, correlated with increased mitochondrial DLP1 expression in murine primary neurons (N2a cells) treated with the prion peptide PrP106-126 in vitro as well as in prion strain-infected hamster brain in vivo. Suppression of DLP1 expression by DPL1 RNAi inhibited prion-induced mitochondrial fragmentation and dysfunction (measured by ADP/ATP ratio, mitochondrial membrane potential, and mitochondrial integrity). We also demonstrated that DLP1 RNAi is neuroprotective against prion peptide in N2a cells as shown by improved cell viability and decreased apoptosis markers, caspase 3 induced by PrP106-126 . On the contrary, overexpression of DLP1 exacerbated mitochondrial dysfunction and cell death. Moreover, inhibition of DLP1 expression ameliorated PrP106-126 -induced neurite loss and synaptic abnormalities (i.e., loss of dendritic spine and PSD-95, a postsynaptic scaffolding protein as a marker of synaptic plasticity) in primary neurons, suggesting that altered DLP1 expression and mitochondrial fragmentation are upstream events that mediate PrP106-126 -induced neuron loss and degeneration. Our findings suggest that DLP1-dependent mitochondrial fragmentation and redistribution plays a pivotal role in PrPSc -associated mitochondria dysfunction and neuron apoptosis. Inhibition of DLP1 may be a novel and effective strategy in the prevention and treatment of prion diseases.
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Affiliation(s)
- Chaosi Li
- National Animal Transmissible Spongiform Encephalopathy Laboratory; State Key Laboratories for Agrobiotechnology; Key Laboratory of Animal Epidemiology and Zoonosis; College of Veterinary Medicine; Ministry of Agriculture; China Agricultural University; Beijing 100193 China
| | - Di Wang
- National Animal Transmissible Spongiform Encephalopathy Laboratory; State Key Laboratories for Agrobiotechnology; Key Laboratory of Animal Epidemiology and Zoonosis; College of Veterinary Medicine; Ministry of Agriculture; China Agricultural University; Beijing 100193 China
| | - Wei Wu
- National Animal Transmissible Spongiform Encephalopathy Laboratory; State Key Laboratories for Agrobiotechnology; Key Laboratory of Animal Epidemiology and Zoonosis; College of Veterinary Medicine; Ministry of Agriculture; China Agricultural University; Beijing 100193 China
| | - Wei Yang
- National Animal Transmissible Spongiform Encephalopathy Laboratory; State Key Laboratories for Agrobiotechnology; Key Laboratory of Animal Epidemiology and Zoonosis; College of Veterinary Medicine; Ministry of Agriculture; China Agricultural University; Beijing 100193 China
| | - Syed Zahid Ali Shah
- National Animal Transmissible Spongiform Encephalopathy Laboratory; State Key Laboratories for Agrobiotechnology; Key Laboratory of Animal Epidemiology and Zoonosis; College of Veterinary Medicine; Ministry of Agriculture; China Agricultural University; Beijing 100193 China
| | - Ying Zhao
- National Animal Transmissible Spongiform Encephalopathy Laboratory; State Key Laboratories for Agrobiotechnology; Key Laboratory of Animal Epidemiology and Zoonosis; College of Veterinary Medicine; Ministry of Agriculture; China Agricultural University; Beijing 100193 China
| | - Yuhan Duan
- National Animal Transmissible Spongiform Encephalopathy Laboratory; State Key Laboratories for Agrobiotechnology; Key Laboratory of Animal Epidemiology and Zoonosis; College of Veterinary Medicine; Ministry of Agriculture; China Agricultural University; Beijing 100193 China
| | - Lu Wang
- National Animal Transmissible Spongiform Encephalopathy Laboratory; State Key Laboratories for Agrobiotechnology; Key Laboratory of Animal Epidemiology and Zoonosis; College of Veterinary Medicine; Ministry of Agriculture; China Agricultural University; Beijing 100193 China
| | - Xiangmei Zhou
- National Animal Transmissible Spongiform Encephalopathy Laboratory; State Key Laboratories for Agrobiotechnology; Key Laboratory of Animal Epidemiology and Zoonosis; College of Veterinary Medicine; Ministry of Agriculture; China Agricultural University; Beijing 100193 China
| | - Deming Zhao
- National Animal Transmissible Spongiform Encephalopathy Laboratory; State Key Laboratories for Agrobiotechnology; Key Laboratory of Animal Epidemiology and Zoonosis; College of Veterinary Medicine; Ministry of Agriculture; China Agricultural University; Beijing 100193 China
| | - Lifeng Yang
- National Animal Transmissible Spongiform Encephalopathy Laboratory; State Key Laboratories for Agrobiotechnology; Key Laboratory of Animal Epidemiology and Zoonosis; College of Veterinary Medicine; Ministry of Agriculture; China Agricultural University; Beijing 100193 China
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32
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Longitudinal intravital imaging of the femoral bone marrow reveals plasticity within marrow vasculature. Nat Commun 2017; 8:2153. [PMID: 29255233 PMCID: PMC5735140 DOI: 10.1038/s41467-017-01538-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 09/25/2017] [Indexed: 01/14/2023] Open
Abstract
The bone marrow is a central organ of the immune system, which hosts complex interactions of bone and immune compartments critical for hematopoiesis, immunological memory, and bone regeneration. Although these processes take place over months, most existing imaging techniques allow us to follow snapshots of only a few hours, at subcellular resolution. Here, we develop a microendoscopic multi-photon imaging approach called LIMB (longitudinal intravital imaging of the bone marrow) to analyze cellular dynamics within the deep marrow. The approach consists of a biocompatible plate surgically fixated to the mouse femur containing a gradient refractive index lens. This microendoscope allows highly resolved imaging, repeatedly at the same regions within marrow tissue, over months. LIMB reveals extensive vascular plasticity during bone healing and steady-state homeostasis. To our knowledge, this vascular plasticity is unique among mammalian tissues, and we expect this insight will decisively change our understanding of essential phenomena occurring within the bone marrow. Longitudinal imaging of bone marrow would shed insight into long-term cellular dynamics within this compartment. Here, the authors develop a multi-photon imaging approach for the mouse femur and reveal extensive vascular plasticity within the bone marrow during bone healing and steady-state homeostasis.
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33
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Song Z, Zhu T, Zhou X, Barrow P, Yang W, Cui Y, Yang L, Zhao D. REST alleviates neurotoxic prion peptide-induced synaptic abnormalities, neurofibrillary degeneration and neuronal death partially via LRP6-mediated Wnt-β-catenin signaling. Oncotarget 2017; 7:12035-52. [PMID: 26919115 PMCID: PMC4914267 DOI: 10.18632/oncotarget.7640] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2015] [Accepted: 02/14/2016] [Indexed: 02/07/2023] Open
Abstract
Prion diseases are a group of infectious neurodegenerative diseases characterized by multiple neuropathological hallmarks including synaptic damage, spongiform degeneration and neuronal death. The factors and mechanisms that maintain cellular morphological integrity and protect against neurodegeneration in prion diseases are still unclear. Here we report that after stimulation with the neurotoxic PrP106-126 fragment in primary cortical neurons, REST translocates from the cytoplasm to the nucleus and protects neurons from harmful effects of PrP106-126. Overexpression of REST reduces pathological damage and abnormal biochemical alterations of neurons induced by PrP106-126 and maintains neuronal viability by stabilizing the level of pro-survival protein FOXO1 and inhibiting the permeability of the mitochondrial outer membrane, release of cytochrome c from mitochondria to cytoplasm and the activation of Capase3. Conversely, knockdown of REST exacerbates morphological damage and inhibits the expression of FOXO1. Additionally, by overexpression or knockdown of LRP6, we further show that LRP6-mediated Wnt-β-catenin signaling partly regulates the expression of REST. Collectively, we demonstrate for the first time novel neuroprotective function of REST in prion diseases and hypothesise that the LRP6-Wnt-β-catenin/REST signaling plays critical and collaborative roles in neuroprotection. This signaling of neuronal survival regulation could be explored as a viable therapeutic target for prion diseases and associated neurodegenerative diseases.
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Affiliation(s)
- Zhiqi Song
- The State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Ting Zhu
- The State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Xiangmei Zhou
- The State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Paul Barrow
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, Leicestershire, UK
| | - Wei Yang
- The State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Yongyong Cui
- The State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Lifeng Yang
- The State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Deming Zhao
- The State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
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Bixel MG, Kusumbe AP, Ramasamy SK, Sivaraj KK, Butz S, Vestweber D, Adams RH. Flow Dynamics and HSPC Homing in Bone Marrow Microvessels. Cell Rep 2017; 18:1804-1816. [PMID: 28199850 PMCID: PMC5318670 DOI: 10.1016/j.celrep.2017.01.042] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 11/28/2016] [Accepted: 01/18/2017] [Indexed: 12/17/2022] Open
Abstract
Measurements of flow velocities at the level of individual arterial vessels and sinusoidal capillaries are crucial for understanding the dynamics of hematopoietic stem and progenitor cell homing in the bone marrow vasculature. We have developed two complementary intravital two-photon imaging approaches to determine blood flow dynamics and velocities in multiple vessel segments by capturing the motion of red blood cells. High-resolution spatiotemporal measurements through a cranial window to determine short-time dynamics of flowing blood cells and repetitive centerline scans were used to obtain a detailed flow-profile map with hemodynamic parameters. In addition, we observed the homing of individual hematopoietic stem and progenitor cells and obtained detailed information on their homing behavior. With our imaging setup, we determined flow patterns at cellular resolution, blood flow velocities and wall shear stress in small arterial vessels and highly branched sinusoidal capillaries, and the cellular dynamics of hematopoietic stem and progenitor cell homing.
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Affiliation(s)
- M Gabriele Bixel
- Department of Tissue Morphogenesis, Max Planck Institute for Molecular Biomedicine, 48149 Münster, Germany; Faculty of Medicine, University of Münster, 48149 Münster, Germany.
| | - Anjali P Kusumbe
- Department of Tissue Morphogenesis, Max Planck Institute for Molecular Biomedicine, 48149 Münster, Germany
| | - Saravana K Ramasamy
- Department of Tissue Morphogenesis, Max Planck Institute for Molecular Biomedicine, 48149 Münster, Germany
| | - Kishor K Sivaraj
- Department of Tissue Morphogenesis, Max Planck Institute for Molecular Biomedicine, 48149 Münster, Germany
| | - Stefan Butz
- Department of Vascular Cell Biology, Max Planck Institute for Molecular Biomedicine, 48149 Münster, Germany
| | - Dietmar Vestweber
- Department of Vascular Cell Biology, Max Planck Institute for Molecular Biomedicine, 48149 Münster, Germany
| | - Ralf H Adams
- Department of Tissue Morphogenesis, Max Planck Institute for Molecular Biomedicine, 48149 Münster, Germany; Faculty of Medicine, University of Münster, 48149 Münster, Germany.
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35
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Goniotaki D, Lakkaraju AKK, Shrivastava AN, Bakirci P, Sorce S, Senatore A, Marpakwar R, Hornemann S, Gasparini F, Triller A, Aguzzi A. Inhibition of group-I metabotropic glutamate receptors protects against prion toxicity. PLoS Pathog 2017; 13:e1006733. [PMID: 29176838 PMCID: PMC5720820 DOI: 10.1371/journal.ppat.1006733] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 12/07/2017] [Accepted: 11/04/2017] [Indexed: 12/29/2022] Open
Abstract
Prion infections cause inexorable, progressive neurological dysfunction and neurodegeneration. Expression of the cellular prion protein PrPC is required for toxicity, suggesting the existence of deleterious PrPC-dependent signaling cascades. Because group-I metabotropic glutamate receptors (mGluR1 and mGluR5) can form complexes with the cellular prion protein (PrPC), we investigated the impact of mGluR1 and mGluR5 inhibition on prion toxicity ex vivo and in vivo. We found that pharmacological inhibition of mGluR1 and mGluR5 antagonized dose-dependently the neurotoxicity triggered by prion infection and by prion-mimetic anti-PrPC antibodies in organotypic brain slices. Prion-mimetic antibodies increased mGluR5 clustering around dendritic spines, mimicking the toxicity of Aβ oligomers. Oral treatment with the mGluR5 inhibitor, MPEP, delayed the onset of motor deficits and moderately prolonged survival of prion-infected mice. Although group-I mGluR inhibition was not curative, these results suggest that it may alleviate the neurological dysfunctions induced by prion diseases.
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Affiliation(s)
| | | | - Amulya N. Shrivastava
- École Normale Supérieure, Institut de Biologie de l'ENS (IBENS) INSERM CNRS PSL Research University, Paris, France
- Paris-Saclay Institute of Neuroscience, CNRS, Gif-sur-Yvette, France
| | - Pamela Bakirci
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Silvia Sorce
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Assunta Senatore
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | | | - Simone Hornemann
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | | | - Antoine Triller
- École Normale Supérieure, Institut de Biologie de l'ENS (IBENS) INSERM CNRS PSL Research University, Paris, France
| | - Adriano Aguzzi
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
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36
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Berry KP, Nedivi E. Spine Dynamics: Are They All the Same? Neuron 2017; 96:43-55. [PMID: 28957675 DOI: 10.1016/j.neuron.2017.08.008] [Citation(s) in RCA: 314] [Impact Index Per Article: 44.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 05/03/2017] [Accepted: 08/04/2017] [Indexed: 11/19/2022]
Abstract
Since Cajal's first drawings of Golgi stained neurons, generations of researchers have been fascinated by the small protrusions, termed spines, studding many neuronal dendrites. Most excitatory synapses in the mammalian CNS are located on dendritic spines, making spines convenient proxies for excitatory synaptic presence. When in vivo imaging revealed that dendritic spines are dynamic structures, their addition and elimination were interpreted as excitatory synapse gain and loss, respectively. Spine imaging has since become a popular assay for excitatory circuit remodeling. In this review, we re-evaluate the validity of using spine dynamics as a straightforward reflection of circuit rewiring. Recent studies tracking both spines and synaptic markers in vivo reveal that 20% of spines lack PSD-95 and are short lived. Although they account for most spine dynamics, their remodeling is unlikely to impact long-term network structure. We discuss distinct roles that spine dynamics can play in circuit remodeling depending on synaptic content.
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Affiliation(s)
- Kalen P Berry
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Elly Nedivi
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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37
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Blumenstock S, Rodrigues EF, Peters F, Blazquez-Llorca L, Schmidt F, Giese A, Herms J. Seeding and transgenic overexpression of alpha-synuclein triggers dendritic spine pathology in the neocortex. EMBO Mol Med 2017; 9:716-731. [PMID: 28351932 PMCID: PMC5412764 DOI: 10.15252/emmm.201607305] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 02/27/2017] [Accepted: 03/02/2017] [Indexed: 12/22/2022] Open
Abstract
Although misfolded and aggregated α-synuclein (α-syn) is recognized in the disease progression of synucleinopathies, its role in the impairment of cortical circuitries and synaptic plasticity remains incompletely understood. We investigated how α-synuclein accumulation affects synaptic plasticity in the mouse somatosensory cortex using two distinct approaches. Long-term in vivo imaging of apical dendrites was performed in mice overexpressing wild-type human α-synuclein. Additionally, intracranial injection of preformed α-synuclein fibrils was performed to induce cortical α-syn pathology. We find that α-synuclein overexpressing mice show decreased spine density and abnormalities in spine dynamics in an age-dependent manner. We also provide evidence for the detrimental effects of seeded α-synuclein aggregates on dendritic architecture. We observed spine loss as well as dystrophic deformation of dendritic shafts in layer V pyramidal neurons. Our results provide a link to the pathophysiology underlying dementia associated with synucleinopathies and may enable the evaluation of potential drug candidates on dendritic spine pathology in vivo.
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Affiliation(s)
- Sonja Blumenstock
- Center for Neuropathology and Prion Research, Ludwig-Maximilians University, Munich, Germany
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Eva F Rodrigues
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Finn Peters
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Lidia Blazquez-Llorca
- Departamento de Psicobiología, Universidad Nacional de Educación a Distancia (UNED), Madrid, Spain
| | - Felix Schmidt
- Center for Neuropathology and Prion Research, Ludwig-Maximilians University, Munich, Germany
- Department of Neurology, Ludwig-Maximilians University, Munich, Germany
| | - Armin Giese
- Center for Neuropathology and Prion Research, Ludwig-Maximilians University, Munich, Germany
| | - Jochen Herms
- Center for Neuropathology and Prion Research, Ludwig-Maximilians University, Munich, Germany
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
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38
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Blazquez-Llorca L, Valero-Freitag S, Rodrigues EF, Merchán-Pérez Á, Rodríguez JR, Dorostkar MM, DeFelipe J, Herms J. High plasticity of axonal pathology in Alzheimer's disease mouse models. Acta Neuropathol Commun 2017; 5:14. [PMID: 28173876 PMCID: PMC5296955 DOI: 10.1186/s40478-017-0415-y] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 01/26/2017] [Indexed: 02/05/2023] Open
Abstract
Axonal dystrophies (AxDs) are swollen and tortuous neuronal processes that are associated with extracellular depositions of amyloid β (Aβ) and have been observed to contribute to synaptic alterations occurring in Alzheimer's disease. Understanding the temporal course of this axonal pathology is of high relevance to comprehend the progression of the disease over time. We performed a long-term in vivo study (up to 210 days of two-photon imaging) with two transgenic mouse models (dE9xGFP-M and APP-PS1xGFP-M). Interestingly, AxDs were formed only in a quarter of GFP-expressing axons near Aβ-plaques, which indicates a selective vulnerability. AxDs, especially those reaching larger sizes, had long lifetimes and appeared as highly plastic structures with large variations in size and shape and axonal sprouting over time. In the case of the APP-PS1 mouse only, the formation of new long axonal segments in dystrophic axons (re-growth phenomenon) was observed. Moreover, new AxDs could appear at the same point of the axon where a previous AxD had been located before disappearance (re-formation phenomenon). In addition, we observed that most AxDs were formed and developed during the imaging period, and numerous AxDs had already disappeared by the end of this time. This work is the first in vivo study analyzing quantitatively the high plasticity of the axonal pathology around Aβ plaques. We hypothesized that a therapeutically early prevention of Aβ plaque formation or their growth might halt disease progression and promote functional axon regeneration and the recovery of neural circuits.
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39
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Maurer J, Hupp S, Bischoff C, Foertsch C, Mitchell TJ, Chakraborty T, Iliev AI. Distinct Neurotoxicity Profile of Listeriolysin O from Listeria monocytogenes. Toxins (Basel) 2017; 9:toxins9010034. [PMID: 28098781 PMCID: PMC5308266 DOI: 10.3390/toxins9010034] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 01/09/2017] [Accepted: 01/10/2017] [Indexed: 11/16/2022] Open
Abstract
Cholesterol-dependent cytolysins (CDCs) are protein toxins that originate from Gram-positive bacteria and contribute substantially to their pathogenicity. CDCs bind membrane cholesterol and build prepores and lytic pores. Some effects of the toxins are observed in non-lytic concentrations. Two pathogens, Streptococcus pneumoniae and Listeria monocytogenes, cause fatal bacterial meningitis, and both produce toxins of the CDC family-pneumolysin and listeriolysin O, respectively. It has been demonstrated that pneumolysin produces dendritic varicosities (dendrite swellings) and dendritic spine collapse in the mouse neocortex, followed by synaptic loss and astrocyte cell shape remodeling without elevated cell death. We utilized primary glial cultures and acute mouse brain slices to examine the neuropathological effects of listeriolysin O and to compare it to pneumolysin with identical hemolytic activity. In cultures, listeriolysin O permeabilized cells slower than pneumolysin did but still initiated non-lytic astrocytic cell shape changes, just as pneumolysin did. In an acute brain slice culture system, listeriolysin O produced dendritic varicosities in an NMDA-dependent manner but failed to cause dendritic spine collapse and cortical astrocyte reorganization. Thus, listeriolysin O demonstrated slower cell permeabilization and milder glial cell remodeling ability than did pneumolysin and lacked dendritic spine collapse capacity but exhibited equivalent dendritic pathology.
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Affiliation(s)
- Jana Maurer
- DFG Membrane/Cytoskeleton Interaction Group, Institute of Pharmacology and Toxicology & Rudolf Virchow Center for Experimental Biomedical Science, University of Würzburg, Versbacherstr. 9, 97078 Würzburg, Germany.
- Institute of Physiology and Pathophysiology, Heidelberg University, Im Neuenheimer Feld 326, 69120 Heidelberg, Germany.
| | - Sabrina Hupp
- DFG Membrane/Cytoskeleton Interaction Group, Institute of Pharmacology and Toxicology & Rudolf Virchow Center for Experimental Biomedical Science, University of Würzburg, Versbacherstr. 9, 97078 Würzburg, Germany.
- Institute of Anatomy, University of Bern, Baltzerstrasse 2, 3012 Bern, Switzerland.
| | - Carolin Bischoff
- DFG Membrane/Cytoskeleton Interaction Group, Institute of Pharmacology and Toxicology & Rudolf Virchow Center for Experimental Biomedical Science, University of Würzburg, Versbacherstr. 9, 97078 Würzburg, Germany.
| | - Christina Foertsch
- DFG Membrane/Cytoskeleton Interaction Group, Institute of Pharmacology and Toxicology & Rudolf Virchow Center for Experimental Biomedical Science, University of Würzburg, Versbacherstr. 9, 97078 Würzburg, Germany.
| | - Timothy J Mitchell
- Chair of Microbial Infection and Immunity, Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
| | - Trinad Chakraborty
- Institute for Medical Microbiology, University of Giessen, Schubertstr. 81, 35392 Giessen, Germany.
| | - Asparouh I Iliev
- DFG Membrane/Cytoskeleton Interaction Group, Institute of Pharmacology and Toxicology & Rudolf Virchow Center for Experimental Biomedical Science, University of Würzburg, Versbacherstr. 9, 97078 Würzburg, Germany.
- Institute of Anatomy, University of Bern, Baltzerstrasse 2, 3012 Bern, Switzerland.
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40
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Zou C, Crux S, Marinesco S, Montagna E, Sgobio C, Shi Y, Shi S, Zhu K, Dorostkar MM, Müller UC, Herms J. Amyloid precursor protein maintains constitutive and adaptive plasticity of dendritic spines in adult brain by regulating D-serine homeostasis. EMBO J 2016; 35:2213-2222. [PMID: 27572463 PMCID: PMC5069548 DOI: 10.15252/embj.201694085] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 08/08/2016] [Indexed: 01/08/2023] Open
Abstract
Dynamic synapses facilitate activity-dependent remodeling of neural circuits, thereby providing the structural substrate for adaptive behaviors. However, the mechanisms governing dynamic synapses in adult brain are still largely unknown. Here, we demonstrate that in the cortex of adult amyloid precursor protein knockout (APP-KO) mice, spine formation and elimination were both reduced while overall spine density remained unaltered. When housed under environmental enrichment, APP-KO mice failed to respond with an increase in spine density. Spine morphology was also altered in the absence of APP The underlying mechanism of these spine abnormalities in APP-KO mice was ascribed to an impairment in D-serine homeostasis. Extracellular D-serine concentration was significantly reduced in APP-KO mice, coupled with an increase of total D-serine. Strikingly, chronic treatment with exogenous D-serine normalized D-serine homeostasis and restored the deficits of spine dynamics, adaptive plasticity, and morphology in APP-KO mice. The cognitive deficit observed in APP-KO mice was also rescued by D-serine treatment. These data suggest that APP regulates homeostasis of D-serine, thereby maintaining the constitutive and adaptive plasticity of dendritic spines in adult brain.
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Affiliation(s)
- Chengyu Zou
- Department for Translational Brain Research, German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Center for Neuropathology and Prion Research, Ludwig-Maximilians-University, Munich, Germany
| | - Sophie Crux
- Department for Translational Brain Research, German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Center for Neuropathology and Prion Research, Ludwig-Maximilians-University, Munich, Germany.,Munich Cluster of Systems Neurology (SyNergy), Ludwig-Maximilians-University, Munich, Germany
| | - Stephane Marinesco
- INSERM U1028, CNRS UMR5292, Lyon Neuroscience Research Center, team TIGER and AniRA Neurochem Technological platform, Lyon, France
| | - Elena Montagna
- Department for Translational Brain Research, German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Center for Neuropathology and Prion Research, Ludwig-Maximilians-University, Munich, Germany
| | - Carmelo Sgobio
- Department for Translational Brain Research, German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Yuan Shi
- Department for Translational Brain Research, German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Center for Neuropathology and Prion Research, Ludwig-Maximilians-University, Munich, Germany
| | - Song Shi
- Center for Neuropathology and Prion Research, Ludwig-Maximilians-University, Munich, Germany
| | - Kaichuan Zhu
- Department for Translational Brain Research, German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Center for Neuropathology and Prion Research, Ludwig-Maximilians-University, Munich, Germany
| | - Mario M Dorostkar
- Center for Neuropathology and Prion Research, Ludwig-Maximilians-University, Munich, Germany
| | - Ulrike C Müller
- Department of Bioinformatics and Functional Genomics, Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Heidelberg, Germany
| | - Jochen Herms
- Department for Translational Brain Research, German Center for Neurodegenerative Diseases (DZNE), Munich, Germany .,Center for Neuropathology and Prion Research, Ludwig-Maximilians-University, Munich, Germany.,Munich Cluster of Systems Neurology (SyNergy), Ludwig-Maximilians-University, Munich, Germany
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41
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Vadakkan KI. Neurodegenerative disorders share common features of "loss of function" states of a proposed mechanism of nervous system functions. Biomed Pharmacother 2016; 83:412-430. [PMID: 27424323 DOI: 10.1016/j.biopha.2016.06.042] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 06/07/2016] [Accepted: 06/25/2016] [Indexed: 12/11/2022] Open
Abstract
Neurodegenerative disorders are highly heterogeneous for the locations affected and the nature of the aggregated proteins. Nearly 80% of the neurodegenerative disorders occur sporadically, indicating that certain factors must combine to initiate the degenerative changes. The contiguous extension of degenerative changes from cell to cell, the association with viral fusion proteins, loss of dendritic spines (postsynaptic terminals), and the eventual degeneration of cells indicate the presence of a unique mechanism for inter-cellular spread of pathology. It is not known whether the "loss of function" states of the still unknown normal nervous system operations can lead to neurodegenerative disorders. Here, the possible loss of function states of a proposed normal nervous system function are examined. A reversible inter-postsynaptic functional LINK (IPL) mechanism, consisting of transient inter-postsynaptic membrane (IPM) hydration exclusion and partial to complete IPM hemifusions, was proposed as a critical step necessary for the binding process and the induction of internal sensations of higher brain functions. When various findings from different neurodegenerative disorders are systematically organized and examined, disease features match the effects of loss of function states of different IPLs. Changes in membrane composition, enlargement of dendritic spines by dopamine and viral fusion proteins are capable of altering the IPLs to form IPM fusion. The latter can lead to the observed lateral spread of pathology, inter-neuronal cytoplasmic content mixing and abnormal protein aggregation. Since both the normal mechanism of reversible IPM hydration exclusion and the pathological process of transient IPM fusion can evade detection, testing their occurrence may provide preventive and therapeutic opportunities for these disorders.
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Tanaka M, Fujiwara A, Suzuki A, Yamasaki T, Hasebe R, Masujin K, Horiuchi M. Comparison of abnormal isoform of prion protein in prion-infected cell lines and primary-cultured neurons by PrPSc-specific immunostaining. J Gen Virol 2016; 97:2030-2042. [PMID: 27267758 DOI: 10.1099/jgv.0.000514] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
We established abnormal isoform of prion protein (PrPSc)-specific double immunostaining using mAb 132, which recognizes aa 119-127 of the PrP molecule, and novel PrPSc-specific mAb 8D5, which recognizes the N-terminal region of the PrP molecule. Using the PrPSc-specific double immunostaining, we analysed PrPSc in immortalized neuronal cell lines and primary cerebral-neuronal cultures infected with prions. The PrPSc-specific double immunostaining showed the existence of PrPSc positive for both mAbs 132 and 8D5, as well as those positive only for either mAb 132 or mAb 8D5. This indicated that double immunostaining detects a greater number of PrPSc species than single immunostaining. Double immunostaining revealed cell-type-dependent differences in PrPSc staining patterns. In the 22 L prion strain-infected Neuro2a (N2a)-3 cells, a subclone of N2a neuroblastoma cell line, or GT1-7, a subclone of the GT1 hypothalamic neuronal cell line, granular PrPSc stains were observed at the perinuclear regions and cytoplasm, whereas unique string-like PrPSc stains were predominantly observed on the surface of the 22 L strain-infected primary cerebral neurons. Only 14 % of PrPSc in the 22 L strain-infected N2a-3 cells were positive for mAb 8D5, indicating that most of the PrPSc in N2a-3 lack the N-terminal portion. In contrast, nearly half PrPSc detected in the 22 L strain-infected primary cerebral neurons were positive for mAb 8D5, suggesting the abundance of full-length PrPSc that possesses the N-terminal portion of PrP. Further analysis of prion-infected primary neurons using PrPSc-specific immunostaining will reveal the neuron-specific mechanism for prion propagation.
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Affiliation(s)
- Misaki Tanaka
- Laboratory of Veterinary Hygiene, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo 060-0818, Japan
| | - Ai Fujiwara
- Laboratory of Veterinary Hygiene, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo 060-0818, Japan
| | - Akio Suzuki
- Laboratory of Veterinary Hygiene, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo 060-0818, Japan
| | - Takeshi Yamasaki
- Laboratory of Veterinary Hygiene, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo 060-0818, Japan
| | - Rie Hasebe
- Laboratory of Veterinary Hygiene, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo 060-0818, Japan
| | - Kentaro Masujin
- National Agriculture Food Research Organization (NARO), 3-1-5 Kannondai, Tsukuba, Ibaraki, 305-0856, Japan.,Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Motohiro Horiuchi
- Laboratory of Veterinary Hygiene, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo 060-0818, Japan
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43
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A Neuronal Culture System to Detect Prion Synaptotoxicity. PLoS Pathog 2016; 12:e1005623. [PMID: 27227882 PMCID: PMC4881977 DOI: 10.1371/journal.ppat.1005623] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 04/19/2016] [Indexed: 12/02/2022] Open
Abstract
Synaptic pathology is an early feature of prion as well as other neurodegenerative diseases. Although the self-templating process by which prions propagate is well established, the mechanisms by which prions cause synaptotoxicity are poorly understood, due largely to the absence of experimentally tractable cell culture models. Here, we report that exposure of cultured hippocampal neurons to PrPSc, the infectious isoform of the prion protein, results in rapid retraction of dendritic spines. This effect is entirely dependent on expression of the cellular prion protein, PrPC, by target neurons, and on the presence of a nine-amino acid, polybasic region at the N-terminus of the PrPC molecule. Both protease-resistant and protease-sensitive forms of PrPSc cause dendritic loss. This system provides new insights into the mechanisms responsible for prion neurotoxicity, and it provides a platform for characterizing different pathogenic forms of PrPSc and testing potential therapeutic agents. Prion diseases are fatal neurodegenerative disorders that cause memory loss, impaired coordination, and abnormal movements. The molecular culprit in prion diseases is PrPSc, an infectious isoform of a host-encoded glycoprotein (PrPC) that can propagate itself by a self-templating mechanism. Whether PrPSc itself is toxic to neurons, and if so, the cellular mechanisms by which it produces neuronal pathology are largely unknown, in part because of the absence of suitable cell culture models. We describe here a hippocampal neuronal cultural system to detect the toxic effect of PrPSc on dendritic spines, which are postsynaptic elements responsible for excitatory synaptic transmission, and which are implicated in learning, memory, and the earliest stages of neurodegenerative diseases. We found that purified, exogenously applied PrPSc causes acute retraction of dendritic spines, an effect that is entirely dependent on expression of PrPC by target neurons, and on the on the presence of a nine-amino acid, polybasic region at the N-terminus of the PrPC molecule. Both protease-resistant and protease-sensitive forms of PrPSc cause dendritic retraction. This system provides new insights into the mechanisms responsible for prion neurotoxicity, and it provides a platform for characterizing different pathogenic forms of PrPSc and testing potential therapeutic agents.
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Herms J, Dorostkar MM. Dendritic Spine Pathology in Neurodegenerative Diseases. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2016; 11:221-50. [PMID: 26907528 DOI: 10.1146/annurev-pathol-012615-044216] [Citation(s) in RCA: 143] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Substantial progress has been made toward understanding the neuropathology, genetic origins, and epidemiology of neurodegenerative diseases, including Alzheimer's disease; tauopathies, such as frontotemporal dementia; α-synucleinopathies, such as Parkinson's disease or dementia with Lewy bodies; Huntington's disease; and amyotrophic lateral sclerosis with dementia, as well as prion diseases. Recent evidence has implicated dendritic spine dysfunction as an important substrate of the pathogenesis of dementia in these disorders. Dendritic spines are specialized structures, extending from the neuronal processes, on which excitatory synaptic contacts are formed, and the loss of dendritic spines correlates with the loss of synaptic function. We review the literature that has implicated direct or indirect structural alterations at dendritic spines in the pathogenesis of major neurodegenerative diseases, focusing on those that lead to dementias such as Alzheimer's, Parkinson's, and Huntington's diseases, as well as frontotemporal dementia and prion diseases. We stress the importance of in vivo studies in animal models.
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Affiliation(s)
- Jochen Herms
- Center for Neuropathology and Prion Research, Ludwig Maximilian University, 81377 Munich, Germany; .,Munich Cluster for Systems Neurology, Ludwig Maximilian University, 81377 Munich, Germany.,German Center for Neurodegenerative Diseases, 81377 Munich, Germany
| | - Mario M Dorostkar
- Center for Neuropathology and Prion Research, Ludwig Maximilian University, 81377 Munich, Germany;
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45
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Victoria GS, Arkhipenko A, Zhu S, Syan S, Zurzolo C. Astrocyte-to-neuron intercellular prion transfer is mediated by cell-cell contact. Sci Rep 2016; 6:20762. [PMID: 26857744 PMCID: PMC4746738 DOI: 10.1038/srep20762] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 01/07/2016] [Indexed: 02/04/2023] Open
Abstract
Prion diseases are caused by misfolding of the cellular protein PrP(C) to an infectious conformer, PrP(Sc). Intercellular PrP(Sc) transfer propagates conversion and allows infectivity to move from the periphery to the brain. However, how prions spread between cells of the central nervous system is unclear. Astrocytes are specialized non-neuronal cells within the brain that have a number of functions indispensable for brain homeostasis. Interestingly, they are one of the earliest sites of prion accumulation in the brain. A fundamental question arising from this observation is whether these cells are involved in intercellular prion transfer and thereby disease propagation. Using co-culture systems between primary infected astrocytes and granule neurons or neuronal cell lines, we provide direct evidence that prion-infected astrocytes can disseminate prion to neurons. Though astrocytes are capable of secreting PrP, this is an inefficient method of transferring prion infectivity. Efficient transfer required co-culturing and direct cell contact. Astrocytes form numerous intercellular connections including tunneling nanotubes, containing PrP(Sc), often colocalized with endolysosomal vesicles, which may constitute the major mechanism of transfer. Because of their role in intercellular transfer of prions astrocytes may influence progression of the disease.
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Affiliation(s)
- Guiliana Soraya Victoria
- Unité Trafic Membranaire et Pathogenèse, Institut Pasteur, 25-28 Rue du Docteur Roux, 75724 Paris CEDEX 15, France
| | - Alexander Arkhipenko
- Unité Trafic Membranaire et Pathogenèse, Institut Pasteur, 25-28 Rue du Docteur Roux, 75724 Paris CEDEX 15, France
| | - Seng Zhu
- Unité Trafic Membranaire et Pathogenèse, Institut Pasteur, 25-28 Rue du Docteur Roux, 75724 Paris CEDEX 15, France
| | - Sylvie Syan
- Unité Trafic Membranaire et Pathogenèse, Institut Pasteur, 25-28 Rue du Docteur Roux, 75724 Paris CEDEX 15, France
| | - Chiara Zurzolo
- Unité Trafic Membranaire et Pathogenèse, Institut Pasteur, 25-28 Rue du Docteur Roux, 75724 Paris CEDEX 15, France
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Neuroinflammation impairs adaptive structural plasticity of dendritic spines in a preclinical model of Alzheimer's disease. Acta Neuropathol 2016; 131:235-246. [PMID: 26724934 PMCID: PMC4713725 DOI: 10.1007/s00401-015-1527-8] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 11/27/2015] [Accepted: 12/16/2015] [Indexed: 12/17/2022]
Abstract
To successfully treat Alzheimer's disease (AD), pathophysiological events in preclinical stages need to be identified. Preclinical AD refers to the stages that exhibit amyloid deposition in the brain but have normal cognitive function, which are replicated in young adult APPswe/PS1deltaE9 (deltaE9) mice. By long-term in vivo two-photon microscopy, we demonstrate impaired adaptive spine plasticity in these transgenic mice illustrated by their failure to increase dendritic spine density and form novel neural connections when housed in enriched environment (EE). Decrease of amyloid plaques by reducing BACE1 activity restores the gain of spine density upon EE in deltaE9 mice, but not the remodeling of neural networks. On the other hand, anti-inflammatory treatment with pioglitazone or interleukin 1 receptor antagonist in deltaE9 mice successfully rescues the impairments in increasing spine density and remodeling of neural networks during EE. Our data suggest that neuroinflammation disrupts experience-dependent structural plasticity of dendritic spines in preclinical stages of AD.
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47
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Maiti P, Manna J, Ilavazhagan G, Rossignol J, Dunbar GL. Molecular regulation of dendritic spine dynamics and their potential impact on synaptic plasticity and neurological diseases. Neurosci Biobehav Rev 2015; 59:208-37. [PMID: 26562682 DOI: 10.1016/j.neubiorev.2015.09.020] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 08/20/2015] [Accepted: 09/07/2015] [Indexed: 12/12/2022]
Abstract
The structure and dynamics of dendritic spines reflect the strength of synapses, which are severely affected in different brain diseases. Therefore, understanding the ultra-structure, molecular signaling mechanism(s) regulating dendritic spine dynamics is crucial. Although, since last century, dynamics of spine have been explored by several investigators in different neurological diseases, but despite countless efforts, a comprehensive understanding of the fundamental etiology and molecular signaling pathways involved in spine pathology is lacking. The purpose of this review is to provide a contextual framework of our current understanding of the molecular mechanisms of dendritic spine signaling, as well as their potential impact on different neurodegenerative and psychiatric diseases, as a format for highlighting some commonalities in function, as well as providing a format for new insights and perspectives into this critical area of research. Additionally, the potential strategies to restore spine structure-function in different diseases are also pointed out. Overall, these informations should help researchers to design new drugs to restore the structure-function of dendritic spine, a "hot site" of synaptic plasticity.
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Affiliation(s)
- Panchanan Maiti
- Field Neurosciences Institute, St. Mary's of Michigan, Saginaw, MI, USA; Department of Psychology and Neurosciences Program, Central Michigan University, Mt. Pleasant, MI, USA.
| | - Jayeeta Manna
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN, USA.
| | - G Ilavazhagan
- Hindustan University, Rajiv Gandhi Salai (OMR), Padur, Kelambakam, Chennai, TN, India.
| | - Julien Rossignol
- Department of Psychology and Neurosciences Program, Central Michigan University, Mt. Pleasant, MI, USA; College of Medicine, Central Michigan University, Mt. Pleasant, MI, USA.
| | - Gary L Dunbar
- Field Neurosciences Institute, St. Mary's of Michigan, Saginaw, MI, USA; Department of Psychology and Neurosciences Program, Central Michigan University, Mt. Pleasant, MI, USA.
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48
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Chapeton J, Gala R, Stepanyants A. Effects of homeostatic constraints on associative memory storage and synaptic connectivity of cortical circuits. Front Comput Neurosci 2015; 9:74. [PMID: 26150784 PMCID: PMC4471370 DOI: 10.3389/fncom.2015.00074] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 05/28/2015] [Indexed: 11/13/2022] Open
Abstract
The impact of learning and long-term memory storage on synaptic connectivity is not completely understood. In this study, we examine the effects of associative learning on synaptic connectivity in adult cortical circuits by hypothesizing that these circuits function in a steady-state, in which the memory capacity of a circuit is maximal and learning must be accompanied by forgetting. Steady-state circuits should be characterized by unique connectivity features. To uncover such features we developed a biologically constrained, exactly solvable model of associative memory storage. The model is applicable to networks of multiple excitatory and inhibitory neuron classes and can account for homeostatic constraints on the number and the overall weight of functional connections received by each neuron. The results show that in spite of a large number of neuron classes, functional connections between potentially connected cells are realized with less than 50% probability if the presynaptic cell is excitatory and generally a much greater probability if it is inhibitory. We also find that constraining the overall weight of presynaptic connections leads to Gaussian connection weight distributions that are truncated at zero. In contrast, constraining the total number of functional presynaptic connections leads to non-Gaussian distributions, in which weak connections are absent. These theoretical predictions are compared with a large dataset of published experimental studies reporting amplitudes of unitary postsynaptic potentials and probabilities of connections between various classes of excitatory and inhibitory neurons in the cerebellum, neocortex, and hippocampus.
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Affiliation(s)
- Julio Chapeton
- Department of Physics and Center for Interdisciplinary Research on Complex Systems, Northeastern University Boston, MA, USA
| | - Rohan Gala
- Department of Physics and Center for Interdisciplinary Research on Complex Systems, Northeastern University Boston, MA, USA
| | - Armen Stepanyants
- Department of Physics and Center for Interdisciplinary Research on Complex Systems, Northeastern University Boston, MA, USA
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49
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Soto C, Satani N. The intricate mechanisms of neurodegeneration in prion diseases. Trends Mol Med 2015; 17:14-24. [PMID: 20889378 DOI: 10.1016/j.molmed.2010.09.001] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Revised: 08/27/2010] [Accepted: 09/01/2010] [Indexed: 12/20/2022]
Abstract
Prion diseases are a group of infectious neurodegenerative diseases with an entirely novel mechanism of transmission, involving a protein-only infectious agent that propagates the disease by transmitting protein conformational changes. The disease results from extensive and progressive brain degeneration. The molecular mechanisms involved in neurodegeneration are not entirely known but involve multiple processes operating simultaneously and synergistically in the brain, including spongiform degeneration, synaptic alterations, brain inflammation, neuronal death and the accumulation of protein aggregates. Here, we review the pathways implicated in prion-induced brain damage and put the pieces together into a possible model of neurodegeneration in prion disorders. A more comprehensive understanding of the molecular basis of brain degeneration is essential to develop a much needed therapy for these devastating diseases.
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Affiliation(s)
- Claudio Soto
- Mitchell Center for Alzheimer's disease and related Brain disorders, Department of Neurology, University of Texas Houston Medical School, 6431 Fannin St, Houston, TX 77030, USA
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50
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Reis R, Hennessy E, Murray C, Griffin ÉW, Cunningham C. At the centre of neuronal, synaptic and axonal pathology in murine prion disease: degeneration of neuroanatomically linked thalamic and brainstem nuclei. Neuropathol Appl Neurobiol 2015; 41:780-97. [PMID: 25727649 PMCID: PMC4744702 DOI: 10.1111/nan.12232] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 02/25/2015] [Indexed: 12/13/2022]
Abstract
Aims The processes by which neurons degenerate in chronic neurodegenerative diseases remain unclear. Synaptic loss and axonal pathology frequently precede neuronal loss and protein aggregation demonstrably spreads along neuroanatomical pathways in many neurodegenerative diseases. The spread of neuronal pathology is less studied. Methods We previously demonstrated severe neurodegeneration in the posterior thalamus of multiple prion disease strains. Here we used the ME7 model of prion disease to examine the nature of this degeneration in the posterior thalamus and the major brainstem projections into this region. Results We objectively quantified neurological decline between 16 and 18 weeks post‐inoculation and observed thalamic subregion‐selective neuronal, synaptic and axonal pathology while demonstrating relatively uniform protease‐resistant prion protein (PrP) aggregation and microgliosis across the posterior thalamus. Novel amyloid precursor protein (APP) pathology was particularly prominent in the thalamic posterior (PO) and ventroposterior lateral (VPL) nuclei. The brainstem nuclei forming the major projections to these thalamic nuclei were examined. Massive neuronal loss in the PO was not matched by significant neuronal loss in the interpolaris (Sp5I), while massive synaptic loss in the ventral posteromedial nucleus (VPM) did correspond with significant neuronal loss in the principal trigeminal nucleus. Likewise, significant VPL synaptic loss was matched by significant neuronal loss in the gracile and cuneate nuclei. Conclusion These findings demonstrate significant spread of neuronal pathology from the thalamus to the brainstem in prion disease. The divergent neuropathological features in adjacent neuronal populations demonstrates that there are discrete pathways to neurodegeneration in different neuronal populations.
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Affiliation(s)
- Renata Reis
- Trinity College Institute of Neuroscience and School of Biochemistry and Immunology, Trinity College Dublin, Dublin, Ireland
| | - Edel Hennessy
- Trinity College Institute of Neuroscience and School of Biochemistry and Immunology, Trinity College Dublin, Dublin, Ireland
| | - Caoimhe Murray
- Trinity College Institute of Neuroscience and School of Biochemistry and Immunology, Trinity College Dublin, Dublin, Ireland
| | - Éadaoin W Griffin
- Trinity College Institute of Neuroscience and School of Biochemistry and Immunology, Trinity College Dublin, Dublin, Ireland
| | - Colm Cunningham
- Trinity College Institute of Neuroscience and School of Biochemistry and Immunology, Trinity College Dublin, Dublin, Ireland
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