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Godoy Muñoz JM, Neset L, Markússon S, Weber S, Krokengen OC, Sutinen A, Christakou E, Lopez AJ, Bramham CR, Kursula P. Structural characterization of two nanobodies targeting the ligand-binding pocket of human Arc. PLoS One 2024; 19:e0300453. [PMID: 38683783 PMCID: PMC11057775 DOI: 10.1371/journal.pone.0300453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 02/27/2024] [Indexed: 05/02/2024] Open
Abstract
The activity-regulated cytoskeleton-associated protein (Arc) is a complex regulator of synaptic plasticity in glutamatergic neurons. Understanding its molecular function is key to elucidate the neurobiology of memory and learning, stress regulation, and multiple neurological and psychiatric diseases. The recent development of anti-Arc nanobodies has promoted the characterization of the molecular structure and function of Arc. This study aimed to validate two anti-Arc nanobodies, E5 and H11, as selective modulators of the human Arc N-lobe (Arc-NL), a domain that mediates several molecular functions of Arc through its peptide ligand binding site. The structural characteristics of recombinant Arc-NL-nanobody complexes were solved at atomic resolution using X-ray crystallography. Both anti-Arc nanobodies bind specifically to the multi-peptide binding site of Arc-NL. Isothermal titration calorimetry showed that the Arc-NL-nanobody interactions occur at nanomolar affinity, and that the nanobodies can displace a TARPγ2-derived peptide from the binding site. Thus, both anti-Arc-NL nanobodies could be used as competitive inhibitors of endogenous Arc ligands. Differences in the CDR3 loops between the two nanobodies indicate that the spectrum of short linear motifs recognized by the Arc-NL should be expanded. We provide a robust biochemical background to support the use of anti-Arc nanobodies in attempts to target Arc-dependent synaptic plasticity. Function-blocking anti-Arc nanobodies could eventually help unravel the complex neurobiology of synaptic plasticity and allow to develop diagnostic and treatment tools.
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Affiliation(s)
| | - Lasse Neset
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | | | - Sarah Weber
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | | | - Aleksi Sutinen
- Faculty of Biochemistry and Molecular Medicine & Biocenter Oulu, University of Oulu, Oulu, Finland
| | | | - Andrea J. Lopez
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | | | - Petri Kursula
- Department of Biomedicine, University of Bergen, Bergen, Norway
- Faculty of Biochemistry and Molecular Medicine & Biocenter Oulu, University of Oulu, Oulu, Finland
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Pileggi S, Colombo EA, Ancona S, Quadri R, Bernardelli C, Colapietro P, Taiana M, Fontana L, Miozzo M, Lesma E, Sirchia SM. Dysfunction in IGF2R Pathway and Associated Perturbations in Autophagy and WNT Processes in Beckwith-Wiedemann Syndrome Cell Lines. Int J Mol Sci 2024; 25:3586. [PMID: 38612397 PMCID: PMC11011696 DOI: 10.3390/ijms25073586] [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: 01/31/2024] [Revised: 03/08/2024] [Accepted: 03/18/2024] [Indexed: 04/14/2024] Open
Abstract
Beckwith-Wiedemann Syndrome (BWS) is an imprinting disorder characterized by overgrowth, stemming from various genetic and epigenetic changes. This study delves into the role of IGF2 upregulation in BWS, focusing on insulin-like growth factor pathways, which are poorly known in this syndrome. We examined the IGF2R, the primary receptor of IGF2, WNT, and autophagy/lysosomal pathways in BWS patient-derived lymphoblastoid cell lines, showing different genetic and epigenetic defects. The findings reveal a decreased expression and mislocalization of IGF2R protein, suggesting receptor dysfunction. Additionally, our results point to a dysregulation in the AKT/GSK-3/mTOR pathway, along with imbalances in autophagy and the WNT pathway. In conclusion, BWS cells, regardless of the genetic/epigenetic profiles, are characterized by alteration of the IGF2R pathway that is associated with the perturbation of the autophagy and lysosome processes. These alterations seem to be a key point of the molecular pathogenesis of BWS and potentially contribute to BWS's characteristic overgrowth and cancer susceptibility. Our study also uncovers alterations in the WNT pathway across all BWS cell lines, consistent with its role in growth regulation and cancer development.
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Affiliation(s)
- Silvana Pileggi
- Medical Genetics, Department of Health Sciences, Università degli Studi di Milano, 20142 Milan, Italy; (S.P.)
| | - Elisa A. Colombo
- Medical Genetics, Department of Health Sciences, Università degli Studi di Milano, 20142 Milan, Italy; (S.P.)
| | - Silvia Ancona
- Pharmacology, Department of Health Sciences, Università degli Studi di Milano, 20142 Milan, Italy (E.L.)
| | - Roberto Quadri
- Department of Biosciences, Università degli Studi di Milano, 20133 Milan, Italy
| | - Clara Bernardelli
- Pharmacology, Department of Health Sciences, Università degli Studi di Milano, 20142 Milan, Italy (E.L.)
| | - Patrizia Colapietro
- Medical Genetics, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, 20122 Milan, Italy
| | - Michela Taiana
- Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, 20122 Milan, Italy
| | - Laura Fontana
- Medical Genetics, Department of Health Sciences, Università degli Studi di Milano, 20142 Milan, Italy; (S.P.)
- Unit of Medical Genetics, ASST Santi Paolo e Carlo, 20142 Milan, Italy
| | - Monica Miozzo
- Medical Genetics, Department of Health Sciences, Università degli Studi di Milano, 20142 Milan, Italy; (S.P.)
- Unit of Medical Genetics, ASST Santi Paolo e Carlo, 20142 Milan, Italy
| | - Elena Lesma
- Pharmacology, Department of Health Sciences, Università degli Studi di Milano, 20142 Milan, Italy (E.L.)
| | - Silvia M. Sirchia
- Medical Genetics, Department of Health Sciences, Università degli Studi di Milano, 20142 Milan, Italy; (S.P.)
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Wang W, Chen C, Wang Q, Ma J, Li Y, Guan Z, Wang R, Chen X. Electroacupuncture pretreatment preserves telomerase reverse transcriptase function and alleviates postoperative cognitive dysfunction by suppressing oxidative stress and neuroinflammation in aged mice. CNS Neurosci Ther 2024; 30:e14373. [PMID: 37501354 PMCID: PMC10848091 DOI: 10.1111/cns.14373] [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: 04/30/2023] [Revised: 07/06/2023] [Accepted: 07/09/2023] [Indexed: 07/29/2023] Open
Abstract
BACKGROUND Elderly patients often exhibit postoperative cognitive dysfunction (POCD), a postsurgical decline in memory and executive function. Oxidative stress and neuroinflammation, both pathological characteristics of the aged brain, contribute to this decline. This study posits that electroacupuncture (EA) stimulation, an effective antioxidant and anti-inflammatory modality, may enhance telomerase reverse transcriptase (TERT) function, the catalytic subunit of telomerase known for its protective properties against cellular senescence and oxidative damage, to alleviate POCD in aged mice. METHODS The animal POCD model was created by subjecting aged mice to abdominal surgery, followed by EA pretreatment at the Baihui acupoint (GV20). Postoperative cognitive function was gauged using the Morris water maze (MWM) test. Hippocampal TERT mRNA levels and telomerase activity were determined through qPCR and a Telomerase PCR ELISA kit, respectively. Oxidative stress was assessed through superoxide dismutase (SOD), reactive oxygen species (ROS), and malondialdehyde (MDA) levels. Iba-1 immunostaining determined the quantity of hippocampal microglia. Additionally, western blotting assessed TERT, autophagy markers, and proinflammatory cytokines at the protein level. RESULTS Abdominal surgery in aged mice significantly decreased telomerase activity and TERT mRNA and protein levels, but increased oxidative stress and neuroinflammation and decreased autophagy in the hippocampus. EA-pretreated mice demonstrated improved postoperative cognitive performance, enhanced telomerase activity, increased TERT protein expression, improved TERT mitochondrial localization, and reduced oxidative damage, autophagy dysfunction, and neuroinflammation. The neuroprotective benefits of EA pretreatment were diminished following TERT knockdown. CONCLUSIONS Our findings underscore the significance of TERT function preservation in alleviating surgery-induced oxidative stress and neuroinflammation in aged mice. A novel neuroprotective mechanism of EA stimulation is highlighted, whereby modulation of TERT and telomerase activity reduces oxidative damage and neuroinflammation. Consequently, maintaining TERT function via EA treatment could serve as an effective strategy for managing POCD in elderly patients.
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Affiliation(s)
- Wei Wang
- Department of AnesthesiologyThe First Affiliated Hospital of Xi'an Jiaotong UniversityXi'an Jiaotong UniversityXi'anShaanxiChina
- Department of AnesthesiologyThe First People's Hospital of FoshanFoshanGuangdongChina
| | - Chen Chen
- Department of Burns and Plastic surgeryHainan Hospital of PLA General HospitalSanyaHainanChina
| | - Qiang Wang
- Department of AnesthesiologyThe First Affiliated Hospital of Xi'an Jiaotong UniversityXi'an Jiaotong UniversityXi'anShaanxiChina
| | - Ji‐Guang Ma
- Department of AnesthesiologyThe First Affiliated Hospital of Xi'an Jiaotong UniversityXi'an Jiaotong UniversityXi'anShaanxiChina
| | - Yan‐Song Li
- Department of AnesthesiologyThe First Affiliated Hospital of Xi'an Jiaotong UniversityXi'an Jiaotong UniversityXi'anShaanxiChina
| | - Zheng Guan
- Department of AnesthesiologyThe First Affiliated Hospital of Xi'an Jiaotong UniversityXi'an Jiaotong UniversityXi'anShaanxiChina
| | - Rui Wang
- Department of AnesthesiologyThe First Affiliated Hospital of Xi'an Jiaotong UniversityXi'an Jiaotong UniversityXi'anShaanxiChina
| | - Xin Chen
- Department of AnesthesiologyThe First People's Hospital of FoshanFoshanGuangdongChina
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Longobardi A, Catania M, Geviti A, Salvi E, Vecchi ER, Bellini S, Saraceno C, Nicsanu R, Squitti R, Binetti G, Di Fede G, Ghidoni R. Autophagy Markers Are Altered in Alzheimer's Disease, Dementia with Lewy Bodies and Frontotemporal Dementia. Int J Mol Sci 2024; 25:1125. [PMID: 38256197 PMCID: PMC10816165 DOI: 10.3390/ijms25021125] [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: 12/12/2023] [Revised: 01/12/2024] [Accepted: 01/15/2024] [Indexed: 01/24/2024] Open
Abstract
The accumulation of protein aggregates defines distinct, yet overlapping pathologies such as Alzheimer's disease (AD), dementia with Lewy bodies (DLB), and frontotemporal dementia (FTD). In this study, we investigated ATG5, UBQLN2, ULK1, and LC3 concentrations in 66 brain specimens and 120 plasma samples from AD, DLB, FTD, and control subjects (CTRL). Protein concentration was measured with ELISA kits in temporal, frontal, and occipital cortex specimens of 32 AD, 10 DLB, 10 FTD, and 14 CTRL, and in plasma samples of 30 AD, 30 DLB, 30 FTD, and 30 CTRL. We found alterations in ATG5, UBQLN2, ULK1, and LC3 levels in patients; ATG5 and UBQLN2 levels were decreased in both brain specimens and plasma samples of patients compared to those of the CTRL, while LC3 levels were increased in the frontal cortex of DLB and FTD patients. In this study, we demonstrate alterations in different steps related to ATG5, UBQLN2, and LC3 autophagy pathways in DLB and FTD patients. Molecular alterations in the autophagic processes could play a role in a shared pathway involved in the pathogenesis of neurodegeneration, supporting the hypothesis of a common molecular mechanism underlying major neurodegenerative dementias and suggesting different potential therapeutic targets in the autophagy pathway for these disorders.
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Affiliation(s)
- Antonio Longobardi
- Molecular Markers Laboratory, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, 25125 Brescia, Italy; (S.B.); (C.S.); (R.N.); (R.S.); (R.G.)
| | - Marcella Catania
- Neurology 5/Neuropathology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, 20133 Milan, Italy; (M.C.); (E.R.V.); (G.D.F.)
| | - Andrea Geviti
- Service of Statistics, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, 25125 Brescia, Italy;
| | - Erika Salvi
- Neuroalgology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, 20133 Milan, Italy;
- Data Science Center, Fondazione IRCCS Istituto Neurologico Carlo Besta, 20133 Milan, Italy
| | - Elena Rita Vecchi
- Neurology 5/Neuropathology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, 20133 Milan, Italy; (M.C.); (E.R.V.); (G.D.F.)
| | - Sonia Bellini
- Molecular Markers Laboratory, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, 25125 Brescia, Italy; (S.B.); (C.S.); (R.N.); (R.S.); (R.G.)
| | - Claudia Saraceno
- Molecular Markers Laboratory, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, 25125 Brescia, Italy; (S.B.); (C.S.); (R.N.); (R.S.); (R.G.)
| | - Roland Nicsanu
- Molecular Markers Laboratory, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, 25125 Brescia, Italy; (S.B.); (C.S.); (R.N.); (R.S.); (R.G.)
| | - Rosanna Squitti
- Molecular Markers Laboratory, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, 25125 Brescia, Italy; (S.B.); (C.S.); (R.N.); (R.S.); (R.G.)
- Dipartimento di Scienze di Laboratorio, Ospedale Isola Tiberina-Gemelli Isola, 00186 Rome, Italy
| | - Giuliano Binetti
- MAC-Memory Clinic and Molecular Markers Laboratory, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, 25125 Brescia, Italy;
| | - Giuseppe Di Fede
- Neurology 5/Neuropathology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, 20133 Milan, Italy; (M.C.); (E.R.V.); (G.D.F.)
| | - Roberta Ghidoni
- Molecular Markers Laboratory, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, 25125 Brescia, Italy; (S.B.); (C.S.); (R.N.); (R.S.); (R.G.)
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5
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Pandey K, Bessières B, Sheng SL, Taranda J, Osten P, Sandovici I, Constancia M, Alberini CM. Neuronal activity drives IGF2 expression from pericytes to form long-term memory. Neuron 2023; 111:3819-3836.e8. [PMID: 37788670 PMCID: PMC10843759 DOI: 10.1016/j.neuron.2023.08.030] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 08/03/2023] [Accepted: 08/31/2023] [Indexed: 10/05/2023]
Abstract
Investigations of memory mechanisms have been, thus far, neuron centric, despite the brain comprising diverse cell types. Using rats and mice, we assessed the cell-type-specific contribution of hippocampal insulin-like growth factor 2 (IGF2), a polypeptide regulated by learning and required for long-term memory formation. The highest level of hippocampal IGF2 was detected in pericytes, the multi-functional mural cells of the microvessels that regulate blood flow, vessel formation, the blood-brain barrier, and immune cell entry into the central nervous system. Learning significantly increased pericytic Igf2 expression in the hippocampus, particularly in the highly vascularized stratum lacunosum moleculare and stratum moleculare layers of the dentate gyrus. Igf2 increases required neuronal activity. Regulated hippocampal Igf2 knockout in pericytes, but not in fibroblasts or neurons, impaired long-term memories and blunted the learning-dependent increase of neuronal immediate early genes (IEGs). Thus, neuronal activity-driven signaling from pericytes to neurons via IGF2 is essential for long-term memory.
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Affiliation(s)
- Kiran Pandey
- Center for Neural Science, New York University, New York, NY 10003, USA
| | | | - Susan L Sheng
- Center for Neural Science, New York University, New York, NY 10003, USA
| | - Julian Taranda
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Pavel Osten
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Ionel Sandovici
- University of Cambridge Metabolic Research Laboratories and MRC Metabolic Diseases Unit, Institute of Metabolic Science, Addenbrookes Hospital, Cambridge, UK; Department of Obstetrics and Gynaecology and National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, UK; Centre for Trophoblast Research, Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
| | - Miguel Constancia
- University of Cambridge Metabolic Research Laboratories and MRC Metabolic Diseases Unit, Institute of Metabolic Science, Addenbrookes Hospital, Cambridge, UK; Department of Obstetrics and Gynaecology and National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, UK; Centre for Trophoblast Research, Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
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6
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Song J, Dikwella N, Sinske D, Roselli F, Knöll B. SRF deletion results in earlier disease onset in a mouse model of amyotrophic lateral sclerosis. JCI Insight 2023; 8:e167694. [PMID: 37339001 PMCID: PMC10445689 DOI: 10.1172/jci.insight.167694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 06/16/2023] [Indexed: 06/22/2023] Open
Abstract
Changes in neuronal activity modulate the vulnerability of motoneurons (MNs) in neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS). So far, the molecular basis of neuronal activity's impact in ALS is poorly understood. Herein, we investigated the impact of deleting the neuronal activity-stimulated transcription factor (TF) serum response factor (SRF) in MNs of SOD1G93A mice. SRF was present in vulnerable MMP9+ MNs. Ablation of SRF in MNs induced an earlier disease onset starting around 7-8 weeks after birth, as revealed by enhanced weight loss and decreased motor ability. This earlier disease onset in SRF-depleted MNs was accompanied by a mild elevation of neuroinflammation and neuromuscular synapse degeneration, whereas overall MN numbers and mortality were unaffected. In SRF-deficient mice, MNs showed impaired induction of autophagy-encoding genes, suggesting a potentially new SRF function in transcriptional regulation of autophagy. Complementary, constitutively active SRF-VP16 enhanced autophagy-encoding gene transcription and autophagy progression in cells. Furthermore, SRF-VP16 decreased ALS-associated aggregate induction. Chemogenetic modulation of neuronal activity uncovered SRF as having important TF-mediating activity-dependent effects, which might be beneficial to reduce ALS disease burden. Thus, our data identify SRF as a gene regulator connecting neuronal activity with the cellular autophagy program initiated in degenerating MNs.
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Affiliation(s)
- Jialei Song
- Institute of Neurobiochemistry and
- Department of Neurology, Ulm University, Ulm, Germany
| | - Natalie Dikwella
- Institute of Neurobiochemistry and
- Department of Neurology, Ulm University, Ulm, Germany
| | | | - Francesco Roselli
- Department of Neurology, Ulm University, Ulm, Germany
- German Center for Neurodegenerative Diseases-Ulm (DZNE-Ulm), Ulm, Germany
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7
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Cummings KA. Protein Accumulation and Impaired Autophagy Underlie Cognitive Dysfunction in Angelman Syndrome. Biol Psychiatry 2023; 94:e1-e3. [PMID: 37316106 DOI: 10.1016/j.biopsych.2023.04.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 04/13/2023] [Indexed: 06/16/2023]
Affiliation(s)
- Kirstie A Cummings
- Department of Neurobiology, University of Alabama at Birmingham Heersink School of Medicine, Birmingham, Alabama.
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8
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Baquedano LE, Bernal EG, Carrion DJ, Delgado AD, Gavidia CM, Kirwan DE, Gilman RH, Verastegui MR. Impaired spatial working memory and reduced hippocampal neuronal density in a rat model of neurocysticercosis. Front Cell Neurosci 2023; 17:1183322. [PMID: 37323586 PMCID: PMC10267319 DOI: 10.3389/fncel.2023.1183322] [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: 03/09/2023] [Accepted: 05/16/2023] [Indexed: 06/17/2023] Open
Abstract
Neurocysticercosis (NCC) is the most common parasitic disease affecting the nervous system and is a leading cause of acquired epilepsy worldwide, as well as cognitive impairment, especially affecting memory. The aim of this study was to evaluate the effect of NCC on spatial working memory and its correlation with hippocampal neuronal density, in a rat model of NCC. This experimental study was conducted on female (n = 60) and male (n = 73) Holtzman rats. NCC was induced by intracranial inoculation of T. solium oncospheres in 14 day-old-rats. Spatial working memory was assessed using the T-maze test at 3, 6, 9, and 12 months post-inoculation, and sensorimotor evaluation was performed at 12 months post-inoculation. Hippocampal neuronal density was evaluated by immunostaining of NeuN-positive cells of the CA1 region. Of the rats inoculated with T. solium oncospheres, 87.2% (82/94) developed NCC. The study showed a significant decline in spatial working memory over a 1-year follow-up period in rats experimentally infected with NCC. Males showed an early decline that started at 3 months, while females demonstrated it at 9 months. Additionally, a decrease in neuronal density was observed in the hippocampus of NCC-infected rats, with a more significant reduction in rats with cysts in the hippocampus than in rats with cysts in other brain areas and control rats. This rat model of NCC provides valuable support for the relationship between neurocysticercosis and spatial working memory deficits. Further investigations are required to determine the mechanisms involved in cognitive impairment and establish the basis for future treatments.
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Affiliation(s)
- Laura E. Baquedano
- Parasitological Diagnostic Laboratory, Faculty of Sciences and Philosophy, Universidad Peruana Cayetano Heredia, Lima, Peru
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima, Peru
- The Cysticercosis Working Group in Peru, Lima, Peru
| | - Edson G. Bernal
- The Cysticercosis Working Group in Peru, Lima, Peru
- Infectious Diseases Research Laboratory, Department of Cellular and Molecular Sciences, Faculty of Sciences and Philosophy, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Daniel J. Carrion
- School of Psychology, Faculty of Philosophy and Human Sciences, Universidad Antonio Ruiz de Montoya, Lima, Peru
| | - Ana D. Delgado
- Infectious Diseases Research Laboratory, Department of Cellular and Molecular Sciences, Faculty of Sciences and Philosophy, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Cesar M. Gavidia
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima, Peru
- The Cysticercosis Working Group in Peru, Lima, Peru
| | - Daniela E. Kirwan
- Infection and Immunity Research Institute, St George’s University of London, London, United Kingdom
| | - Robert H. Gilman
- The Cysticercosis Working Group in Peru, Lima, Peru
- Department of International Health, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MA, United States
| | - Manuela R. Verastegui
- The Cysticercosis Working Group in Peru, Lima, Peru
- Infectious Diseases Research Laboratory, Department of Cellular and Molecular Sciences, Faculty of Sciences and Philosophy, Universidad Peruana Cayetano Heredia, Lima, Peru
- Asociación Benéfica PRISMA, Lima, Peru
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9
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Kallergi E, Siva Sankar D, Matera A, Kolaxi A, Paolicelli RC, Dengjel J, Nikoletopoulou V. Profiling of purified autophagic vesicle degradome in the maturing and aging brain. Neuron 2023:S0896-6273(23)00384-7. [PMID: 37279748 DOI: 10.1016/j.neuron.2023.05.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 03/19/2023] [Accepted: 05/11/2023] [Indexed: 06/08/2023]
Abstract
Autophagy disorders prominently affect the brain, entailing neurodevelopmental and neurodegenerative phenotypes in adolescence or aging, respectively. Synaptic and behavioral deficits are largely recapitulated in mouse models with ablation of autophagy genes in brain cells. Yet, the nature and temporal dynamics of brain autophagic substrates remain insufficiently characterized. Here, we immunopurified LC3-positive autophagic vesicles (LC3-pAVs) from the mouse brain and proteomically profiled their content. Moreover, we characterized the LC3-pAV content that accumulates after macroautophagy impairment, validating a brain autophagic degradome. We reveal selective pathways for aggrephagy, mitophagy, and ER-phagy via selective autophagy receptors, and the turnover of numerous synaptic substrates, under basal conditions. To gain insight into the temporal dynamics of autophagic protein turnover, we quantitatively compared adolescent, adult, and aged brains, revealing critical periods of enhanced mitophagy or degradation of synaptic substrates. Overall, this resource unbiasedly characterizes the contribution of autophagy to proteostasis in the maturing, adult, and aged brain.
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Affiliation(s)
- Emmanouela Kallergi
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | | | - Alessandro Matera
- Department of Biomedical Sciences, University of Lausanne, Lausanne, Switzerland
| | - Angeliki Kolaxi
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | | | - Joern Dengjel
- Department of Biology, University of Fribourg, 1700 Fribourg, Switzerland.
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10
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Wang Y, Lin J, Li J, Yan L, Li W, He X, Ma H. Chronic Neuronal Inactivity Utilizes the mTOR-TFEB Pathway to Drive Transcription-Dependent Autophagy for Homeostatic Up-Scaling. J Neurosci 2023; 43:2631-2652. [PMID: 36868861 PMCID: PMC10089247 DOI: 10.1523/jneurosci.0146-23.2023] [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: 01/24/2023] [Revised: 02/16/2023] [Accepted: 02/26/2023] [Indexed: 03/05/2023] Open
Abstract
Activity-dependent changes in protein expression are critical for neuronal plasticity, a fundamental process for the processing and storage of information in the brain. Among the various forms of plasticity, homeostatic synaptic up-scaling is unique in that it is induced primarily by neuronal inactivity. However, precisely how the turnover of synaptic proteins occurs in this homeostatic process remains unclear. Here, we report that chronically inhibiting neuronal activity in primary cortical neurons prepared from embryonic day (E)18 Sprague Dawley rats (both sexes) induces autophagy, thereby regulating key synaptic proteins for up-scaling. Mechanistically, chronic neuronal inactivity causes dephosphorylation of ERK and mTOR, which induces transcription factor EB (TFEB)-mediated cytonuclear signaling and drives transcription-dependent autophagy to regulate αCaMKII and PSD95 during synaptic up-scaling. Together, these findings suggest that mTOR-dependent autophagy, which is often triggered by metabolic stressors such as starvation, is recruited and sustained during neuronal inactivity to maintain synaptic homeostasis, a process that ensures proper brain function and if impaired can cause neuropsychiatric disorders such as autism.SIGNIFICANCE STATEMENT In the mammalian brain, protein turnover is tightly controlled by neuronal activation to ensure key neuronal functions during long-lasting synaptic plasticity. However, a long-standing question is how this process occurs during synaptic up-scaling, a process that requires protein turnover but is induced by neuronal inactivation. Here, we report that mTOR-dependent signaling, which is often triggered by metabolic stressors such as starvation, is "hijacked" by chronic neuronal inactivation, which then serves as a nucleation point for transcription factor EB (TFEB) cytonuclear signaling that drives transcription-dependent autophagy for up-scaling. These results provide the first evidence of a physiological role of mTOR-dependent autophagy in enduing neuronal plasticity, thereby connecting major themes in cell biology and neuroscience via a servo loop that mediates autoregulation in the brain.
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Affiliation(s)
- Yang Wang
- Department of Neurobiology, Affiliated Mental Health Center and Hangzhou Seventh People's Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
- Liangzhu Laboratory, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou 311121, China
- National Health Commission of the PRC (NHC) and Chinese Academy of Medical Sciences (CAMS) Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou 310058, China
| | - Jingran Lin
- Department of Neurobiology, Affiliated Mental Health Center and Hangzhou Seventh People's Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
- Liangzhu Laboratory, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou 311121, China
- National Health Commission of the PRC (NHC) and Chinese Academy of Medical Sciences (CAMS) Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou 310058, China
| | - Jiarui Li
- Department of Neurobiology, Affiliated Mental Health Center and Hangzhou Seventh People's Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
- Liangzhu Laboratory, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou 311121, China
- National Health Commission of the PRC (NHC) and Chinese Academy of Medical Sciences (CAMS) Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou 310058, China
| | - Lu Yan
- Department of Neurobiology, Affiliated Mental Health Center and Hangzhou Seventh People's Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
- Liangzhu Laboratory, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou 311121, China
- National Health Commission of the PRC (NHC) and Chinese Academy of Medical Sciences (CAMS) Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou 310058, China
| | - Wenwen Li
- Department of Neurobiology, Affiliated Mental Health Center and Hangzhou Seventh People's Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
- Liangzhu Laboratory, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou 311121, China
- National Health Commission of the PRC (NHC) and Chinese Academy of Medical Sciences (CAMS) Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou 310058, China
| | - Xingzhi He
- Department of Neurobiology, Affiliated Mental Health Center and Hangzhou Seventh People's Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
- Liangzhu Laboratory, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou 311121, China
- National Health Commission of the PRC (NHC) and Chinese Academy of Medical Sciences (CAMS) Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou 310058, China
| | - Huan Ma
- Department of Neurobiology, Affiliated Mental Health Center and Hangzhou Seventh People's Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
- Liangzhu Laboratory, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou 311121, China
- National Health Commission of the PRC (NHC) and Chinese Academy of Medical Sciences (CAMS) Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou 310058, China
- Research Units for Emotion and Emotion disorders, Chinese Academy of Medical Sciences, Beijing 100050, China
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11
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Alberini CM. IGF2 in memory, neurodevelopmental disorders, and neurodegenerative diseases. Trends Neurosci 2023; 46:488-502. [PMID: 37031050 DOI: 10.1016/j.tins.2023.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Revised: 01/27/2023] [Accepted: 03/12/2023] [Indexed: 04/08/2023]
Abstract
Insulin-like growth factor 2 (IGF2) emerged as a critical mechanism of synaptic plasticity and learning and memory. Deficits in IGF2 in the brain, serum, or cerebrospinal fluid (CSF) are associated with brain diseases, including Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and amyotrophic lateral sclerosis (ALS). Increasing IGF2 levels enhances memory in healthy animals and reverses numerous symptoms in laboratory models of aging, neurodevelopmental disorders, and neurodegenerative diseases. These effects occur via the IGF2 receptor (IGF2R) - a receptor that is highly expressed in neurons and regulates protein trafficking, synthesis, and degradation. Here, I summarize the current knowledge regarding IGF2 expression and functions in the brain, particularly in memory, and propose a novel conceptual model for IGF2/IGF2R mechanisms of action in brain health and diseases.
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12
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Khoury R, Saad J, Jabre V, Ghayad LM, Khalifeh M, Houbeika R, El Ahmad P, Mezher A, El Masri D, Haddad Z, Eid F, Barmo N, Nasrallah P, Sleiman SF, Stephan JS. Autophagy regulates the release of exercise factors and their beneficial effects on spatial memory recall. Heliyon 2023; 9:e14705. [PMID: 37025840 PMCID: PMC10070545 DOI: 10.1016/j.heliyon.2023.e14705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 02/28/2023] [Accepted: 03/15/2023] [Indexed: 03/29/2023] Open
Abstract
Exercise promotes learning and memory recall as well as rescues cognitive decline associated with aging. The positive effects of exercise are mediated by circulatory factors that predominantly increase Brain Derived Neurotrophic Factor (BDNF) signaling in the hippocampus. Identifying the pathways that regulate the release of the circulatory factors by various tissues during exercise and that mediate hippocampal Mus musculus Bdnf expression will allow us to harness the therapeutic potential of exercise. Here, we report that two weeks of voluntary exercise in male mice activates autophagy in the hippocampus by increasing LC3B protein levels (p = 0.0425) and that autophagy is necessary for exercise-induced spatial learning and memory retention (p < 0.001; exercise + autophagy inhibitor chloroquine CQ versus exercise). We place autophagy downstream of hippocampal BDNF signaling and identify a positive feedback activation between the pathways. We also assess whether the modulation of autophagy outside the nervous system is involved in mediating exercise's effect on learning and memory recall. Indeed, plasma collected from young exercise mice promote spatial learning (p = 0.0446; exercise versus sedentary plasma) and memory retention in aged inactive mice (p = 0.0303; exercise versus sedentary plasma), whereas plasma collected from young exercise mice that received the autophagy inhibitor chloroquine diphosphate failed to do so. We show that the release of exercise factors that reverse the symptoms of aging into the circulation is dependent on the activation of autophagy in young animals. Indeed, we show that the release of the exercise factor, beta-hydroxybutyrate (DBHB), into the circulation, is autophagy-dependent and that DBHB promotes spatial learning and memory formation (p = 0.0005) by inducing hippocampal autophagy (p = 0.0479). These results implicate autophagy in peripheral tissues and in the hippocampus in mediating the effects of exercise on learning and memory recall and identify DBHB as a candidate endogenous exercise factor whose release and positive effects are autophagy-dependent.
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13
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Neuronal membrane proteasomes regulate neuronal circuit activity in vivo and are required for learning-induced behavioral plasticity. Proc Natl Acad Sci U S A 2023; 120:e2216537120. [PMID: 36630455 PMCID: PMC9934054 DOI: 10.1073/pnas.2216537120] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Protein degradation is critical for brain function through processes that remain incompletely understood. Here, we investigated the in vivo function of the 20S neuronal membrane proteasome (NMP) in the brain of Xenopus laevis tadpoles. With biochemistry, immunohistochemistry, and electron microscopy, we demonstrated that NMPs are conserved in the tadpole brain and preferentially degrade neuronal activity-induced newly synthesized proteins in vivo. Using in vivo calcium imaging in the optic tectum, we showed that acute NMP inhibition rapidly increased spontaneous neuronal activity, resulting in hypersynchronization across tectal neurons. At the circuit level, inhibiting NMPs abolished learning-dependent improvement in visuomotor behavior in live animals and caused a significant deterioration in basal behavioral performance following visual training with enhanced visual experience. Our data provide in vivo characterization of NMP functions in the vertebrate nervous system and suggest that NMP-mediated degradation of activity-induced nascent proteins may serve as a homeostatic modulatory mechanism in neurons that is critical for regulating neuronal activity and experience-dependent circuit plasticity.
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14
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Aria F, Pandey K, Alberini CM. Excessive Protein Accumulation and Impaired Autophagy in the Hippocampus of Angelman Syndrome Modeled in Mice. Biol Psychiatry 2022:S0006-3223(22)01796-6. [PMID: 36764852 DOI: 10.1016/j.biopsych.2022.11.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 11/03/2022] [Accepted: 11/18/2022] [Indexed: 12/12/2022]
Abstract
BACKGROUND Angelman syndrome (AS), a neurodevelopmental disorder caused by abnormalities of the 15q11.2-q13.1 chromosome region, is characterized by impairment of cognitive and motor functions, sleep problems, and seizures. How the genetic defects of AS produce these neurological symptoms is unclear. Mice modeling AS (AS mice) accumulate activity-regulated cytoskeleton-associated protein (ARC/ARG3.1), a neuronal immediate early gene (IEG) critical for synaptic plasticity. This accumulation suggests an altered protein metabolism. METHODS Focusing on the dorsal hippocampus (dHC), a brain region critical for memory formation and cognitive functions, we assessed levels and tissue distribution of IEGs, de novo protein synthesis, and markers of protein synthesis, endosomes, autophagy, and synaptic functions in AS mice at baseline and following learning. We also tested autophagic flux and memory retention following autophagy-promoting treatment. RESULTS AS dHC exhibited accumulation of IEGs ARC, FOS, and EGR1; autophagy proteins MLP3B, SQSTM1, and LAMP1; and reduction of the endosomal protein RAB5A. AS dHC also had increased levels of de novo protein synthesis, impaired autophagic flux with accumulation of autophagosome, and altered synaptic protein levels. Contextual fear conditioning significantly increased levels of IEGs and autophagy proteins, de novo protein synthesis, and autophagic flux in the dHC of normal mice, but not in AS mice. Enhancing autophagy in the dHC alleviated AS-related memory and autophagic flux impairments. CONCLUSIONS A major biological deficit of AS brain is a defective protein metabolism, particularly that dynamically regulated by learning, resulting in stalled autophagy and accumulation of neuronal proteins. Activating autophagy ameliorates AS cognitive impairments and dHC protein accumulation.
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Affiliation(s)
- Francesca Aria
- Center for Neural Science, New York University, New York, New York
| | - Kiran Pandey
- Center for Neural Science, New York University, New York, New York
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15
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Overhoff M, Tellkamp F, Hess S, Tolve M, Tutas J, Faerfers M, Ickert L, Mohammadi M, De Bruyckere E, Kallergi E, Delle Vedove A, Nikoletopoulou V, Wirth B, Isensee J, Hucho T, Puchkov D, Isbrandt D, Krueger M, Kloppenburg P, Kononenko NL. Autophagy regulates neuronal excitability by controlling cAMP/protein kinase A signaling at the synapse. EMBO J 2022; 41:e110963. [PMID: 36217825 PMCID: PMC9670194 DOI: 10.15252/embj.2022110963] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 09/10/2022] [Accepted: 09/14/2022] [Indexed: 01/13/2023] Open
Abstract
Autophagy provides nutrients during starvation and eliminates detrimental cellular components. However, accumulating evidence indicates that autophagy is not merely a housekeeping process. Here, by combining mouse models of neuron-specific ATG5 deficiency in either excitatory or inhibitory neurons with quantitative proteomics, high-content microscopy, and live-imaging approaches, we show that autophagy protein ATG5 functions in neurons to regulate cAMP-dependent protein kinase A (PKA)-mediated phosphorylation of a synapse-confined proteome. This function of ATG5 is independent of bulk turnover of synaptic proteins and requires the targeting of PKA inhibitory R1 subunits to autophagosomes. Neuronal loss of ATG5 causes synaptic accumulation of PKA-R1, which sequesters the PKA catalytic subunit and diminishes cAMP/PKA-dependent phosphorylation of postsynaptic cytoskeletal proteins that mediate AMPAR trafficking. Furthermore, ATG5 deletion in glutamatergic neurons augments AMPAR-dependent excitatory neurotransmission and causes the appearance of spontaneous recurrent seizures in mice. Our findings identify a novel role of autophagy in regulating PKA signaling at glutamatergic synapses and suggest the PKA as a target for restoration of synaptic function in neurodegenerative conditions with autophagy dysfunction.
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Affiliation(s)
- Melina Overhoff
- Cologne Excellence Cluster Cellular Stress Response in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany
| | - Frederik Tellkamp
- Cologne Excellence Cluster Cellular Stress Response in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany,Faculty of Mathematics and Natural Sciences, Institute of GeneticsUniversity of CologneCologneGermany
| | - Simon Hess
- Cologne Excellence Cluster Cellular Stress Response in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany,Faculty of Mathematics and Natural Sciences, Institute of ZoologyUniversity of CologneCologneGermany
| | - Marianna Tolve
- Cologne Excellence Cluster Cellular Stress Response in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany,Center for Physiology and Pathophysiology, Faculty of Medicine and University Hospital CologneUniversity of CologneCologneGermany
| | - Janine Tutas
- Cologne Excellence Cluster Cellular Stress Response in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany
| | - Marcel Faerfers
- Cologne Excellence Cluster Cellular Stress Response in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany
| | - Lotte Ickert
- Cologne Excellence Cluster Cellular Stress Response in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany,Center for Physiology and Pathophysiology, Faculty of Medicine and University Hospital CologneUniversity of CologneCologneGermany
| | - Milad Mohammadi
- Cologne Excellence Cluster Cellular Stress Response in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany
| | - Elodie De Bruyckere
- Cologne Excellence Cluster Cellular Stress Response in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany
| | - Emmanouela Kallergi
- Département des Neurosciences FondamentalesUniversity of LausanneLausanneSwitzerland
| | - Andrea Delle Vedove
- Institute of Human Genetics, Center for Molecular Medicine Cologne, Center for Rare Diseases Cologne, Faculty of Medicine and University Hospital CologneUniversity of CologneCologneGermany
| | | | - Brunhilde Wirth
- Faculty of Mathematics and Natural Sciences, Institute of GeneticsUniversity of CologneCologneGermany,Institute of Human Genetics, Center for Molecular Medicine Cologne, Center for Rare Diseases Cologne, Faculty of Medicine and University Hospital CologneUniversity of CologneCologneGermany
| | - Joerg Isensee
- Translational Pain Research, Department of Anaesthesiology and Intensive Care Medicine, Faculty of Medicine and University Hospital CologneUniversity of CologneCologneGermany
| | - Tim Hucho
- Translational Pain Research, Department of Anaesthesiology and Intensive Care Medicine, Faculty of Medicine and University Hospital CologneUniversity of CologneCologneGermany
| | - Dmytro Puchkov
- Leibniz Institute for Molecular Pharmacology (FMP)BerlinGermany
| | - Dirk Isbrandt
- Institute for Molecular and Behavioral Neuroscience, Faculty of Medicine and University Hospital CologneUniversity of CologneCologneGermany,Experimental NeurophysiologyGerman Center for Neurodegenerative DiseasesBonnGermany
| | - Marcus Krueger
- Cologne Excellence Cluster Cellular Stress Response in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany,Faculty of Mathematics and Natural Sciences, Institute of GeneticsUniversity of CologneCologneGermany
| | - Peter Kloppenburg
- Cologne Excellence Cluster Cellular Stress Response in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany,Faculty of Mathematics and Natural Sciences, Institute of ZoologyUniversity of CologneCologneGermany
| | - Natalia L Kononenko
- Cologne Excellence Cluster Cellular Stress Response in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany,Center for Physiology and Pathophysiology, Faculty of Medicine and University Hospital CologneUniversity of CologneCologneGermany
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16
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Impact of Autophagy Impairment on Experience- and Diet-Related Synaptic Plasticity. Int J Mol Sci 2022; 23:ijms23169228. [PMID: 36012495 PMCID: PMC9408861 DOI: 10.3390/ijms23169228] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 08/09/2022] [Accepted: 08/13/2022] [Indexed: 11/16/2022] Open
Abstract
The beneficial effects of diet and exercise on brain function are traditionally attributed to the enhancement of autophagy, which plays a key role in neuroprotection via the degradation of potentially harmful intracellular structures. The molecular machinery of autophagy has also been suggested to influence synaptic signaling via interaction with trafficking and endocytosis of synaptic vesicles and proteins. Still, the role of autophagy in the regulation of synaptic plasticity remains elusive, especially in the mammalian brain. We explored the impact of autophagy on synaptic transmission and homeostatic and acute synaptic plasticity using transgenic mice with induced deletion of the Beclin1 protein. We observed down-regulation of glutamatergic and up-regulation of GABAergic synaptic currents and impairment of long-term plasticity in the neocortex and hippocampus of Beclin1-deficient mice. Beclin1 deficiency also significantly reduced the effects of environmental enrichment, caloric restriction and its pharmacological mimetics (metformin and resveratrol) on synaptic transmission and plasticity. Taken together, our data strongly support the importance of autophagy in the regulation of excitatory and inhibitory synaptic transmission and synaptic plasticity in the neocortex and hippocampus. Our results also strongly suggest that the positive modulatory actions of metformin and resveratrol in acute and homeostatic synaptic plasticity, and therefore their beneficial effects on brain function, occur via the modulation of autophagy.
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17
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Sidibe DK, Vogel MC, Maday S. Organization of the autophagy pathway in neurons. Curr Opin Neurobiol 2022; 75:102554. [PMID: 35649324 PMCID: PMC9990471 DOI: 10.1016/j.conb.2022.102554] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 03/28/2022] [Accepted: 04/12/2022] [Indexed: 01/18/2023]
Abstract
Macroautophagy (hereafter referred to as autophagy) is an essential quality-control pathway in neurons, which face unique functional and morphological challenges in maintaining the integrity of organelles and the proteome. To overcome these challenges, neurons have developed compartment-specific pathways for autophagy. In this review, we discuss the organization of the autophagy pathway, from autophagosome biogenesis, trafficking, to clearance, in the neuron. We dissect the compartment-specific mechanisms and functions of autophagy in axons, dendrites, and the soma. Furthermore, we highlight examples of how steps along the autophagy pathway are impaired in the context of aging and neurodegenerative disease, which underscore the critical importance of autophagy in maintaining neuronal function and survival.
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Affiliation(s)
- David K Sidibe
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Maria C Vogel
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Sandra Maday
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104, USA.
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18
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Keeping Synapses in Shape: Degradation Pathways in the Healthy and Aging Brain. Neuronal Signal 2022; 6:NS20210063. [PMID: 35813265 PMCID: PMC9208270 DOI: 10.1042/ns20210063] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 05/30/2022] [Accepted: 05/31/2022] [Indexed: 11/17/2022] Open
Abstract
Synapses maintain their molecular composition, plasticity and function through the concerted action of protein synthesis and removal. The complex and polarized neuronal architecture poses specific challenges to the logistics of protein and organelle turnover since protein synthesis and degradation mainly happen in the cell soma. In addition, post-mitotic neurons accumulate damage over a lifetime, challenging neuronal degradative pathways and making them particularly susceptible to the effects of aging. This review will summarize the current knowledge on neuronal protein turnover mechanisms with a particular focus on the presynapse, including the proteasome, autophagy and the endolysosomal route and their roles in regulating presynaptic proteostasis and function. In addition, the author will discuss how physiological brain aging, which entails a progressive decline in cognitive functions, affects synapses and the degradative machinery.
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19
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Kallergi E, Daskalaki AD, Kolaxi A, Camus C, Ioannou E, Mercaldo V, Haberkant P, Stein F, Sidiropoulou K, Dalezios Y, Savitski MM, Bagni C, Choquet D, Hosy E, Nikoletopoulou V. Dendritic autophagy degrades postsynaptic proteins and is required for long-term synaptic depression in mice. Nat Commun 2022; 13:680. [PMID: 35115539 PMCID: PMC8814153 DOI: 10.1038/s41467-022-28301-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 01/14/2022] [Indexed: 01/18/2023] Open
Abstract
The pruning of dendritic spines during development requires autophagy. This process is facilitated by long-term depression (LTD)-like mechanisms, which has led to speculation that LTD, a fundamental form of synaptic plasticity, also requires autophagy. Here, we show that the induction of LTD via activation of NMDA receptors or metabotropic glutamate receptors initiates autophagy in the postsynaptic dendrites in mice. Dendritic autophagic vesicles (AVs) act in parallel with the endocytic machinery to remove AMPA receptor subunits from the membrane for degradation. During NMDAR-LTD, key postsynaptic proteins are sequestered for autophagic degradation, as revealed by quantitative proteomic profiling of purified AVs. Pharmacological inhibition of AV biogenesis, or conditional ablation of atg5 in pyramidal neurons abolishes LTD and triggers sustained potentiation in the hippocampus. These deficits in synaptic plasticity are recapitulated by knockdown of atg5 specifically in postsynaptic pyramidal neurons in the CA1 area. Conducive to the role of synaptic plasticity in behavioral flexibility, mice with autophagy deficiency in excitatory neurons exhibit altered response in reversal learning. Therefore, local assembly of the autophagic machinery in dendrites ensures the degradation of postsynaptic components and facilitates LTD expression.
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Affiliation(s)
- Emmanouela Kallergi
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, 1005, Switzerland
| | | | - Angeliki Kolaxi
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, 1005, Switzerland
| | - Come Camus
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, F-33000, Bordeaux, France
| | - Evangelia Ioannou
- School of Biological Sciences, University of Crete, Heraklion, 70013, Greece
| | - Valentina Mercaldo
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, 1005, Switzerland
| | - Per Haberkant
- Proteomic Core Facility (PCF), European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Frank Stein
- Proteomic Core Facility (PCF), European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | | | - Yannis Dalezios
- School of Medicine, University of Crete, Heraklion, 71003, Greece
- Institute of Applied and Computational Mathematics (IACM), Foundation for Research and Technology-Hellas (FORTH), Heraklion, Greece
| | - Mikhail M Savitski
- Proteomic Core Facility (PCF), European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
- Genome Biology Unit, European Molecular Biology Laboratory (EMBL), University of Rome Tor Vergata, Rome, 00133, Italy
| | - Claudia Bagni
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, 1005, Switzerland
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, 00133, Italy
| | - Daniel Choquet
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, F-33000, Bordeaux, France
- University of Bordeaux, CNRS, INSERM, Bordeaux Imaging Center, BIC, UMS 3420, US 4, F-33000, Bordeaux, France
| | - Eric Hosy
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, F-33000, Bordeaux, France
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20
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Hantak MP, Einstein J, Kearns RB, Shepherd JD. Intercellular Communication in the Nervous System Goes Viral. Trends Neurosci 2021; 44:248-259. [PMID: 33485691 PMCID: PMC8041237 DOI: 10.1016/j.tins.2020.12.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 11/19/2020] [Accepted: 12/30/2020] [Indexed: 12/20/2022]
Abstract
Viruses and transposable elements are major drivers of evolution and make up over half the sequences in the human genome. In some cases, these elements are co-opted to perform biological functions for the host. Recent studies made the surprising observation that the neuronal gene Arc forms virus-like protein capsids that can transfer RNA between neurons to mediate a novel intercellular communication pathway. Phylogenetic analyses showed that mammalian Arc is derived from an ancient retrotransposon of the Ty3/gypsy family and contains homology to the retroviral Gag polyproteins. The Drosophila Arc homologs, which are independently derived from the same family of retrotransposons, also mediate cell-to-cell signaling of RNA at the neuromuscular junction; a striking example of convergent evolution. Here we propose an Arc 'life cycle', based on what is known about retroviral Gag, and discuss how elucidating these biological processes may lead to novel insights into brain plasticity and memory.
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Affiliation(s)
- Michael P Hantak
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, UT, USA
| | - Jenifer Einstein
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, UT, USA
| | - Rachel B Kearns
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, UT, USA
| | - Jason D Shepherd
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, UT, USA.
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21
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Kulkarni VV, Anand A, Herr JB, Miranda C, Vogel MC, Maday S. Synaptic activity controls autophagic vacuole motility and function in dendrites. J Cell Biol 2021; 220:211926. [PMID: 33783472 PMCID: PMC8020715 DOI: 10.1083/jcb.202002084] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 01/06/2021] [Accepted: 03/04/2021] [Indexed: 02/07/2023] Open
Abstract
Macroautophagy (hereafter “autophagy”) is a lysosomal degradation pathway that is important for learning and memory, suggesting critical roles for autophagy at the neuronal synapse. Little is known, however, about the molecular details of how autophagy is regulated with synaptic activity. Here, we used live-cell confocal microscopy to define the autophagy pathway in primary hippocampal neurons under various paradigms of synaptic activity. We found that synaptic activity regulates the motility of autophagic vacuoles (AVs) in dendrites. Stimulation of synaptic activity dampens AV motility, whereas silencing synaptic activity induces AV motility. Activity-dependent effects on dendritic AV motility are local and reversible. Importantly, these effects are compartment specific, occurring in dendrites and not in axons. Most strikingly, synaptic activity increases the presence of degradative autolysosomes in dendrites and not in axons. On the basis of our findings, we propose a model whereby synaptic activity locally controls AV dynamics and function within dendrites that may regulate the synaptic proteome.
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Affiliation(s)
- Vineet Vinay Kulkarni
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA
| | - Anip Anand
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA
| | - Jessica Brandt Herr
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA
| | - Christina Miranda
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA
| | - Maria Chalokh Vogel
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA
| | - Sandra Maday
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA
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22
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Ma Y, Li C, He Y, Fu T, Song L, Ye Q, Zhang F. Beclin-1/LC3-II dependent macroautophagy was uninfluenced in ischemia-challenged vascular endothelial cells. Genes Dis 2021; 9:549-561. [PMID: 35224166 PMCID: PMC8843992 DOI: 10.1016/j.gendis.2021.02.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 01/17/2021] [Accepted: 02/21/2021] [Indexed: 12/27/2022] Open
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