1
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Bretou M, Sannerud R, Escamilla-Ayala A, Leroy T, Vrancx C, Van Acker ZP, Perdok A, Vermeire W, Vorsters I, Van Keymolen S, Maxson M, Pavie B, Wierda K, Eskelinen EL, Annaert W. Accumulation of APP C-terminal fragments causes endolysosomal dysfunction through the dysregulation of late endosome to lysosome-ER contact sites. Dev Cell 2024; 59:1571-1592.e9. [PMID: 38626765 DOI: 10.1016/j.devcel.2024.03.030] [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: 10/18/2021] [Revised: 11/02/2023] [Accepted: 03/20/2024] [Indexed: 04/18/2024]
Abstract
Neuronal endosomal and lysosomal abnormalities are among the early changes observed in Alzheimer's disease (AD) before plaques appear. However, it is unclear whether distinct endolysosomal defects are temporally organized and how altered γ-secretase function or amyloid precursor protein (APP) metabolism contribute to these changes. Inhibiting γ-secretase chronically, in mouse embryonic fibroblast and hippocampal neurons, led to a gradual endolysosomal collapse initiated by decreased lysosomal calcium and increased cholesterol, causing downstream defects in endosomal recycling and maturation. This endolysosomal demise is γ-secretase dependent, requires membrane-tethered APP cytoplasmic domains, and is rescued by APP depletion. APP C-terminal fragments (CTFs) localized to late endosome/lysosome-endoplasmic reticulum contacts; an excess of APP-CTFs herein reduced lysosomal Ca2+ refilling from the endoplasmic reticulum, promoting cholesterol accretion. Tonic regulation by APP-CTFs provides a mechanistic explanation for their cellular toxicity: failure to timely degrade APP-CTFs sustains downstream signaling, instigating lysosomal dyshomeostasis, as observed in prodromal AD. This is the opposite of substrates such as Notch, which require intramembrane proteolysis to initiate signaling.
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Affiliation(s)
- Marine Bretou
- Laboratory for Membrane Trafficking, VIB-Center for Brain and Disease Research, Leuven, Belgium; Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Ragna Sannerud
- Laboratory for Membrane Trafficking, VIB-Center for Brain and Disease Research, Leuven, Belgium; Department of Neurosciences, KU Leuven, Leuven, Belgium
| | | | - Tom Leroy
- Laboratory for Membrane Trafficking, VIB-Center for Brain and Disease Research, Leuven, Belgium; Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Céline Vrancx
- Laboratory for Membrane Trafficking, VIB-Center for Brain and Disease Research, Leuven, Belgium; Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Zoë P Van Acker
- Laboratory for Membrane Trafficking, VIB-Center for Brain and Disease Research, Leuven, Belgium; Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Anika Perdok
- Laboratory for Membrane Trafficking, VIB-Center for Brain and Disease Research, Leuven, Belgium; Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Wendy Vermeire
- Laboratory for Membrane Trafficking, VIB-Center for Brain and Disease Research, Leuven, Belgium; Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Inge Vorsters
- Laboratory for Membrane Trafficking, VIB-Center for Brain and Disease Research, Leuven, Belgium; Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Sophie Van Keymolen
- Laboratory for Membrane Trafficking, VIB-Center for Brain and Disease Research, Leuven, Belgium; Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Michelle Maxson
- Cell Biology Program, The Hospital for Sick Children, Department of Biochemistry, University of Toronto, Toronto, Canada
| | - Benjamin Pavie
- VIB-BioImaging Core, VIB-Center for Brain and Disease Research, Leuven, Belgium
| | - Keimpe Wierda
- Electrophysiology Expertise Unit, VIB-Center for Brain and Disease Research, Leuven, Belgium
| | | | - Wim Annaert
- Laboratory for Membrane Trafficking, VIB-Center for Brain and Disease Research, Leuven, Belgium; Department of Neurosciences, KU Leuven, Leuven, Belgium.
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2
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Shabani K, Pigeon J, Benaissa Touil Zariouh M, Liu T, Saffarian A, Komatsu J, Liu E, Danda N, Becmeur-Lefebvre M, Limame R, Bohl D, Parras C, Hassan BA. The temporal balance between self-renewal and differentiation of human neural stem cells requires the amyloid precursor protein. SCIENCE ADVANCES 2023; 9:eadd5002. [PMID: 37327344 PMCID: PMC10275593 DOI: 10.1126/sciadv.add5002] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 05/11/2023] [Indexed: 06/18/2023]
Abstract
Neurogenesis in the developing human cerebral cortex occurs at a particularly slow rate owing in part to cortical neural progenitors preserving their progenitor state for a relatively long time, while generating neurons. How this balance between the progenitor and neurogenic state is regulated, and whether it contributes to species-specific brain temporal patterning, is poorly understood. Here, we show that the characteristic potential of human neural progenitor cells (NPCs) to remain in a progenitor state as they generate neurons for a prolonged amount of time requires the amyloid precursor protein (APP). In contrast, APP is dispensable in mouse NPCs, which undergo neurogenesis at a much faster rate. Mechanistically, APP cell-autonomously contributes to protracted neurogenesis through suppression of the proneurogenic activator protein-1 transcription factor and facilitation of canonical WNT signaling. We propose that the fine balance between self-renewal and differentiation is homeostatically regulated by APP, which may contribute to human-specific temporal patterns of neurogenesis.
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Affiliation(s)
- Khadijeh Shabani
- Institut du Cerveau–Paris Brain Institute–ICM, Sorbonne Université, INSERM, CNRS, Hôpital Pitié-Salpêtrière, Paris, France
| | - Julien Pigeon
- Institut du Cerveau–Paris Brain Institute–ICM, Sorbonne Université, INSERM, CNRS, Hôpital Pitié-Salpêtrière, Paris, France
| | - Marwan Benaissa Touil Zariouh
- Institut du Cerveau–Paris Brain Institute–ICM, Sorbonne Université, INSERM, CNRS, Hôpital Pitié-Salpêtrière, Paris, France
| | - Tengyuan Liu
- Institut du Cerveau–Paris Brain Institute–ICM, Sorbonne Université, INSERM, CNRS, Hôpital Pitié-Salpêtrière, Paris, France
| | - Azadeh Saffarian
- Scipio bioscience, iPEPS-ICM, Hôpital Pitié-Salpêtrière, Paris, France
| | - Jun Komatsu
- Scipio bioscience, iPEPS-ICM, Hôpital Pitié-Salpêtrière, Paris, France
| | - Elise Liu
- Institut du Cerveau–Paris Brain Institute–ICM, Sorbonne Université, INSERM, CNRS, Hôpital Pitié-Salpêtrière, Paris, France
| | - Natasha Danda
- Institut du Cerveau–Paris Brain Institute–ICM, Sorbonne Université, INSERM, CNRS, Hôpital Pitié-Salpêtrière, Paris, France
| | - Mathilde Becmeur-Lefebvre
- Genetics and Foetopathology, Centre Hospitalier Regional d’Orleans–Hôpital de la Source, Orleans, France
| | - Ridha Limame
- Institut du Cerveau–Paris Brain Institute–ICM, Sorbonne Université, INSERM, CNRS, Hôpital Pitié-Salpêtrière, Paris, France
| | - Delphine Bohl
- Institut du Cerveau–Paris Brain Institute–ICM, Sorbonne Université, INSERM, CNRS, Hôpital Pitié-Salpêtrière, Paris, France
| | - Carlos Parras
- Institut du Cerveau–Paris Brain Institute–ICM, Sorbonne Université, INSERM, CNRS, Hôpital Pitié-Salpêtrière, Paris, France
| | - Bassem A. Hassan
- Institut du Cerveau–Paris Brain Institute–ICM, Sorbonne Université, INSERM, CNRS, Hôpital Pitié-Salpêtrière, Paris, France
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3
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Song C, Broadie K. Fragile X mental retardation protein coordinates neuron-to-glia communication for clearance of developmentally transient brain neurons. Proc Natl Acad Sci U S A 2023; 120:e2216887120. [PMID: 36920921 PMCID: PMC10041173 DOI: 10.1073/pnas.2216887120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 02/07/2023] [Indexed: 03/16/2023] Open
Abstract
In the developmental remodeling of brain circuits, neurons are removed by glial phagocytosis to optimize adult behavior. Fragile X mental retardation protein (FMRP) regulates neuron-to-glia signaling to drive glial phagocytosis for targeted neuron pruning. We find that FMRP acts in a mothers against decapentaplegic (Mad)-insulin receptor (InR)-protein kinase B (Akt) pathway to regulate pretaporter (Prtp) and amyloid precursor protein-like (APPL) signals directing this glial clearance. Neuronal RNAi of Drosophila fragile X mental retardation 1 (dfmr1) elevates mad transcript levels and increases pMad signaling. Neuronal dfmr1 and mad RNAi both elevate phospho-protein kinase B (pAkt) and delay neuron removal but cause opposite effects on InR expression. Genetically correcting pAkt levels in the mad RNAi background restores normal remodeling. Consistently, neuronal dfmr1 and mad RNAi both decrease Prtp levels, whereas neuronal InR and akt RNAi increase Prtp levels, indicating FMRP works with pMad and insulin signaling to tightly regulate Prtp signaling and thus control glial phagocytosis for correct circuit remodeling. Neuronal dfmr1 and mad and akt RNAi all decrease APPL levels, with the pathway signaling higher glial endolysosome activity for phagocytosis. These findings reveal a FMRP-dependent control pathway for neuron-to-glia communication in neuronal pruning, identifying potential molecular mechanisms for devising fragile X syndrome treatments.
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Affiliation(s)
- Chunzhu Song
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN37235
| | - Kendal Broadie
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN37235
- Department of Cell and Developmental Biology, Vanderbilt University and Medical Center, Nashville, TN37235
- Kennedy Center for Research on Human Development, Vanderbilt University and Medical Center, Nashville, TN37235
- Vanderbilt Brain Institute, Vanderbilt University and Medical Center, Nashville, TN37235
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4
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Song C, Broadie K. Dysregulation of BMP, Wnt, and Insulin Signaling in Fragile X Syndrome. Front Cell Dev Biol 2022; 10:934662. [PMID: 35880195 PMCID: PMC9307498 DOI: 10.3389/fcell.2022.934662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 06/06/2022] [Indexed: 01/21/2023] Open
Abstract
Drosophila models of neurological disease contribute tremendously to research progress due to the high conservation of human disease genes, the powerful and sophisticated genetic toolkit, and the rapid generation time. Fragile X syndrome (FXS) is the most prevalent heritable cause of intellectual disability and autism spectrum disorders, and the Drosophila FXS disease model has been critical for the genetic screening discovery of new intercellular secretion mechanisms. Here, we focus on the roles of three major signaling pathways: BMP, Wnt, and insulin-like peptides. We present Drosophila FXS model defects compared to mouse models in stem cells/embryos, the glutamatergic neuromuscular junction (NMJ) synapse model, and the developing adult brain. All three of these secreted signaling pathways are strikingly altered in FXS disease models, giving new mechanistic insights into impaired cellular outcomes and neurological phenotypes. Drosophila provides a powerful genetic screening platform to expand understanding of these secretory mechanisms and to test cellular roles in both peripheral and central nervous systems. The studies demonstrate the importance of exploring broad genetic interactions and unexpected regulatory mechanisms. We discuss a number of research avenues to pursue BMP, Wnt, and insulin signaling in future FXS investigations and the development of potential therapeutics.
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Affiliation(s)
- Chunzhu Song
- Department of Biological Sciences, College of Arts and Science, Vanderbilt University, Nashville, TN, United States
| | - Kendal Broadie
- Department of Biological Sciences, College of Arts and Science, Vanderbilt University, Nashville, TN, United States
- Department of Cell and Developmental Biology, School of Medicine, Vanderbilt University, Nashville, TN, United States
- Kennedy Center for Research on Human Development, Nashville, TN, United States
- Vanderbilt Brain Institute, School of Medicine, Vanderbilt University and Medical Center, Nashville, TN, United States
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5
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Cho Y, Bae HG, Okun E, Arumugam TV, Jo DG. Physiology and pharmacology of amyloid precursor protein. Pharmacol Ther 2022; 235:108122. [PMID: 35114285 DOI: 10.1016/j.pharmthera.2022.108122] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 01/17/2022] [Accepted: 01/25/2022] [Indexed: 02/06/2023]
Abstract
Amyloid precursor protein (APP) is an evolutionarily conserved transmembrane protein and a well-characterized precursor protein of amyloid-beta (Aβ) peptides, which accumulate in the brains of individuals with Alzheimer's disease (AD)-related pathologies. Aβ has been extensively investigated since the amyloid hypothesis in AD was proposed. Besides Aβ, previous studies on APP and its proteolytic cleavage products have suggested their diverse pathological and physiological functions. However, their roles still have not been thoroughly understood. In this review, we extensively discuss the evolutionarily-conserved biology of APP, including its structure and processing pathway, as well as recent findings on the physiological roles of APP and its fragments in the central nervous system and peripheral nervous system. We have also elaborated upon the current status of APP-targeted therapeutic approaches for AD treatment by discussing inhibitors of several proteases participating in APP processing, including α-, β-, and γ-secretases. Finally, we have highlighted the future perspectives pertaining to further research and the potential clinical role of APP.
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Affiliation(s)
- Yoonsuk Cho
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, South Korea
| | - Han-Gyu Bae
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, South Korea
| | - Eitan Okun
- The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan 5290002, Israel; The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 5290002, Israel; The Pauld Feder Laboratory on Alzheimer's Disease Research, Israel
| | - Thiruma V Arumugam
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, South Korea; School of Life Sciences, La Trobe University, Bundoora, Victoria, Australia.
| | - Dong-Gyu Jo
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, South Korea; Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University, Seoul 06351, South Korea; Biomedical Institute for Convergence, Sungkyunkwan University, Suwon 16419, South Korea.
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6
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Boulanger A, Dura JM. Neuron-glia crosstalk in neuronal remodeling and degeneration: Neuronal signals inducing glial cell phagocytic transformation in Drosophila. Bioessays 2022; 44:e2100254. [PMID: 35315125 DOI: 10.1002/bies.202100254] [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: 10/25/2021] [Revised: 03/04/2022] [Accepted: 03/07/2022] [Indexed: 11/09/2022]
Abstract
Neuronal remodeling is a conserved mechanism that eliminates unwanted neurites and can include the loss of cell bodies. In these processes, a key role for glial cells in events from synaptic pruning to neuron elimination has been clearly identified in the last decades. Signals sent from dying neurons or neurites to be removed are received by appropriate glial cells. After receiving these signals, glial cells infiltrate degenerating sites and then, engulf and clear neuronal debris through phagocytic mechanisms. There are few identified or proposed signals and receptors involved in neuron-glia crosstalk, which induces the transformation of glial cells to phagocytes during neuronal remodeling in Drosophila. Many of these signaling pathways are conserved in mammals. Here, we particularly emphasize the role of Orion, a recently identified neuronal CX3 C chemokine-like secreted protein, which induces astrocyte infiltration and engulfment during mushroom body neuronal remodeling. Although, chemokine signaling was not described previously in insects we propose that chemokine-like involvement in neuron/glial cell interaction is an evolutionarily ancient mechanism.
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Affiliation(s)
- Ana Boulanger
- IGH, Université de Montpellier, CNRS, Montpellier, France
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7
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Lambert E, Saha O, Soares Landeira B, Melo de Farias AR, Hermant X, Carrier A, Pelletier A, Gadaut J, Davoine L, Dupont C, Amouyel P, Bonnefond A, Lafont F, Abdelfettah F, Verstreken P, Chapuis J, Barois N, Delahaye F, Dermaut B, Lambert JC, Costa MR, Dourlen P. The Alzheimer susceptibility gene BIN1 induces isoform-dependent neurotoxicity through early endosome defects. Acta Neuropathol Commun 2022; 10:4. [PMID: 34998435 PMCID: PMC8742943 DOI: 10.1186/s40478-021-01285-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 10/23/2021] [Indexed: 02/08/2023] Open
Abstract
The Bridging Integrator 1 (BIN1) gene is a major susceptibility gene for Alzheimer’s disease (AD). Deciphering its pathophysiological role is challenging due to its numerous isoforms. Here we observed in Drosophila that human BIN1 isoform1 (BIN1iso1) overexpression, contrary to human BIN1 isoform8 (BIN1iso8) and human BIN1 isoform9 (BIN1iso9), induced an accumulation of endosomal vesicles and neurodegeneration. Systematic search for endosome regulators able to prevent BIN1iso1-induced neurodegeneration indicated that a defect at the early endosome level is responsible for the neurodegeneration. In human induced neurons (hiNs) and cerebral organoids, BIN1 knock-out resulted in the narrowing of early endosomes. This phenotype was rescued by BIN1iso1 but not BIN1iso9 expression. Finally, BIN1iso1 overexpression also led to an increase in the size of early endosomes and neurodegeneration in hiNs. Altogether, our data demonstrate that the AD susceptibility gene BIN1, and especially BIN1iso1, contributes to early-endosome size deregulation, which is an early pathophysiological hallmark of AD pathology.
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8
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Jabeen K, Rehman K, Akash MSH. Genetic mutations of APOEε4 carriers in cardiovascular patients lead to the development of insulin resistance and risk of Alzheimer's disease. J Biochem Mol Toxicol 2021; 36:e22953. [PMID: 34757642 DOI: 10.1002/jbt.22953] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 10/11/2021] [Accepted: 11/01/2021] [Indexed: 12/19/2022]
Abstract
Type 2 diabetes mellitus and Alzheimer's disease (AD), both are chronic and progressive diseases. Many cardiovascular and genetic risk factors are considered responsible for the development of AD and diabetes mellitus (DM). Genetic risk factor such as apolipoprotein E (APOE) plays a critical role in the progression of AD. Specifically, APOEε4 is genetically the strongest isoform associated with neuronal insulin deficiency, altered lipid homeostasis, and metabolism, decreased glucose uptake, impaired gray matter volume, and cerebrovascular functions. In this article, we have summarized the mechanisms of cardiovascular disturbances associated with AD and DM, impact of amyloid-β aggregation, and neurofibrillary tangles formation in AD. Moreover, cardiovascular risk factors leading to insulin resistance (IR) and amyloid-β aggregation are highlighted along with the effects of APOE risk alleles on cerebral, lipid, and cholesterol metabolism leading to CVD-mediated IR. Correspondingly, the contribution of IR, genetic and cardiovascular risk factors in amyloid-β aggregation, which may lead to the late onset of AD and DM, has been also discussed. In short, IR is related to significantly lower cerebral glucose metabolism, which sequentially forecasts poorer memory performance. Hence, there will be more chances for neural glucose intolerance and impairment of cognitive function in cardiac patients, particularly APOEε4 carriers having IR. Hence, this review provides a better understanding of the corresponding crosstalk among different pathways. This will help to investigate the rational application of preventive measures against IR and cognitive dysfunction, specifically in APOEε4 carriers' cardio-metabolic patients.
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Affiliation(s)
- Komal Jabeen
- Department of Pharmacy, University of Agriculture, Faisalabad, Pakistan.,Institute of Physiology and Pharmacology, University of Agriculture, Faisalabad, Pakistan
| | - Kanwal Rehman
- Department of Pharmacy, University of Agriculture, Faisalabad, Pakistan
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9
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Nutraceutical and Probiotic Approaches to Examine Molecular Interactions of the Amyloid Precursor Protein APP in Drosophila Models of Alzheimer's Disease. Int J Mol Sci 2021; 22:ijms22137022. [PMID: 34209883 PMCID: PMC8269328 DOI: 10.3390/ijms22137022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 06/24/2021] [Accepted: 06/24/2021] [Indexed: 12/12/2022] Open
Abstract
Studies using animal models have shed light into the molecular and cellular basis for the neuropathology observed in patients with Alzheimer’s disease (AD). In particular, the role of the amyloid precursor protein (APP) plays a crucial role in the formation of senile plaques and aging-dependent degeneration. Here, we focus our review on recent findings using the Drosophila AD model to expand our understanding of APP molecular function and interactions, including insights gained from the fly homolog APP-like (APPL). Finally, as there is still no cure for AD, we review some approaches that have shown promising results in ameliorating AD-associated phenotypes, with special attention on the use of nutraceuticals and their molecular effects, as well as interactions with the gut microbiome. Overall, the phenomena described here are of fundamental significance for understanding network development and degeneration. Given the highly conserved nature of fundamental signaling pathways, the insight gained from animal models such as Drosophila melanogaster will likely advance the understanding of the mammalian brain, and thus be relevant to human health.
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10
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Steubler V, Erdinger S, Back MK, Ludewig S, Fässler D, Richter M, Han K, Slomianka L, Amrein I, von Engelhardt J, Wolfer DP, Korte M, Müller UC. Loss of all three APP family members during development impairs synaptic function and plasticity, disrupts learning, and causes an autism-like phenotype. EMBO J 2021; 40:e107471. [PMID: 34008862 PMCID: PMC8204861 DOI: 10.15252/embj.2020107471] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 03/29/2021] [Accepted: 04/01/2021] [Indexed: 12/15/2022] Open
Abstract
The key role of APP for Alzheimer pathogenesis is well established. However, perinatal lethality of germline knockout mice lacking the entire APP family has so far precluded the analysis of its physiological functions for the developing and adult brain. Here, we generated conditional APP/APLP1/APLP2 triple KO (cTKO) mice lacking the APP family in excitatory forebrain neurons from embryonic day 11.5 onwards. NexCre cTKO mice showed altered brain morphology with agenesis of the corpus callosum and disrupted hippocampal lamination. Further, NexCre cTKOs revealed reduced basal synaptic transmission and drastically reduced long-term potentiation that was associated with reduced dendritic length and reduced spine density of pyramidal cells. With regard to behavior, lack of the APP family leads not only to severe impairments in a panel of tests for learning and memory, but also to an autism-like phenotype including repetitive rearing and climbing, impaired social communication, and deficits in social interaction. Together, our study identifies essential functions of the APP family during development, for normal hippocampal function and circuits important for learning and social behavior.
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Affiliation(s)
- Vicky Steubler
- Department of Functional GenomicsInstitute of Pharmacy and Molecular BiotechnologyHeidelberg UniversityHeidelbergGermany
| | - Susanne Erdinger
- Department of Functional GenomicsInstitute of Pharmacy and Molecular BiotechnologyHeidelberg UniversityHeidelbergGermany
| | - Michaela K Back
- Institute of PathophysiologyFocus Program Translational Neuroscience (FTN)University Medical Center of the Johannes Gutenberg University MainzMainzGermany
| | - Susann Ludewig
- Division of Cellular NeurobiologyZoological Institute, TU BraunschweigBraunschweigGermany
- Helmholtz Centre for Infection Research, Neuroinflammation and Neurodegeneration GroupBraunschweigGermany
| | - Dominique Fässler
- Department of Functional GenomicsInstitute of Pharmacy and Molecular BiotechnologyHeidelberg UniversityHeidelbergGermany
| | - Max Richter
- Department of Functional GenomicsInstitute of Pharmacy and Molecular BiotechnologyHeidelberg UniversityHeidelbergGermany
| | - Kang Han
- Department of Functional GenomicsInstitute of Pharmacy and Molecular BiotechnologyHeidelberg UniversityHeidelbergGermany
| | - Lutz Slomianka
- Institute of Anatomy and Zurich Center for Integrative Human PhysiologyUniversity of ZurichZurichSwitzerland
| | - Irmgard Amrein
- Institute of Anatomy and Zurich Center for Integrative Human PhysiologyUniversity of ZurichZurichSwitzerland
| | - Jakob von Engelhardt
- Institute of PathophysiologyFocus Program Translational Neuroscience (FTN)University Medical Center of the Johannes Gutenberg University MainzMainzGermany
| | - David P Wolfer
- Institute of Anatomy and Zurich Center for Integrative Human PhysiologyUniversity of ZurichZurichSwitzerland
- Institute of Human Movement SciencesETH ZurichZurichSwitzerland
| | - Martin Korte
- Division of Cellular NeurobiologyZoological Institute, TU BraunschweigBraunschweigGermany
- Helmholtz Centre for Infection Research, Neuroinflammation and Neurodegeneration GroupBraunschweigGermany
| | - Ulrike C Müller
- Department of Functional GenomicsInstitute of Pharmacy and Molecular BiotechnologyHeidelberg UniversityHeidelbergGermany
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11
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Perez-Catalan NA, Doe CQ, Ackerman SD. The role of astrocyte-mediated plasticity in neural circuit development and function. Neural Dev 2021; 16:1. [PMID: 33413602 PMCID: PMC7789420 DOI: 10.1186/s13064-020-00151-9] [Citation(s) in RCA: 72] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 12/26/2020] [Indexed: 02/03/2023] Open
Abstract
Neuronal networks are capable of undergoing rapid structural and functional changes called plasticity, which are essential for shaping circuit function during nervous system development. These changes range from short-term modifications on the order of milliseconds, to long-term rearrangement of neural architecture that could last for the lifetime of the organism. Neural plasticity is most prominent during development, yet also plays a critical role during memory formation, behavior, and disease. Therefore, it is essential to define and characterize the mechanisms underlying the onset, duration, and form of plasticity. Astrocytes, the most numerous glial cell type in the human nervous system, are integral elements of synapses and are components of a glial network that can coordinate neural activity at a circuit-wide level. Moreover, their arrival to the CNS during late embryogenesis correlates to the onset of sensory-evoked activity, making them an interesting target for circuit plasticity studies. Technological advancements in the last decade have uncovered astrocytes as prominent regulators of circuit assembly and function. Here, we provide a brief historical perspective on our understanding of astrocytes in the nervous system, and review the latest advances on the role of astroglia in regulating circuit plasticity and function during nervous system development and homeostasis.
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Affiliation(s)
- Nelson A Perez-Catalan
- Institute of Neuroscience, Howard Hughes Medical Institute, University of Oregon, Eugene, OR, USA
- Kennedy Center, Department of Pediatrics, The University of Chicago, Chicago, IL, USA
| | - Chris Q Doe
- Institute of Neuroscience, Howard Hughes Medical Institute, University of Oregon, Eugene, OR, USA
| | - Sarah D Ackerman
- Institute of Neuroscience, Howard Hughes Medical Institute, University of Oregon, Eugene, OR, USA.
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