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Chen J, Chen JS, Li S, Zhang F, Deng J, Zeng LH, Tan J. Amyloid Precursor Protein: A Regulatory Hub in Alzheimer's Disease. Aging Dis 2024; 15:201-225. [PMID: 37307834 PMCID: PMC10796103 DOI: 10.14336/ad.2023.0308] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 03/08/2023] [Indexed: 06/14/2023] Open
Abstract
Decades of research have demonstrated an incontrovertible role of amyloid-β (Aβ) in the etiology of Alzheimer's disease (AD). However, the overemphasis on the pathological impacts of Aβ may obscure the role of its metabolic precursor, amyloid precursor protein (APP), as a significant hub in the occurrence and progression of AD. The complicated enzymatic processing, ubiquitous receptor-like properties, and abundant expression of APP in the brain, as well as its close links with systemic metabolism, mitochondrial function and neuroinflammation, imply that APP plays multifaceted roles in AD. In this review, we briefly describe the evolutionarily conserved biological characteristics of APP, including its structure, functions and enzymatic processing. We also discuss the possible involvement of APP and its enzymatic metabolites in AD, both detrimental and beneficial. Finally, we describe pharmacological agents or genetic approaches with the capability to reduce APP expression or inhibit its cellular internalization, which can ameliorate multiple aspects of AD pathologies and halt disease progression. These approaches provide a basis for further drug development to combat this terrible disease.
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Affiliation(s)
- Jiang Chen
- Key Laboratory of Endemic and Ethnic Diseases, Laboratory of Molecular Biology, Ministry of Education, Guizhou Medical University, Guiyang, Guizhou, China.
- Key Laboratory of Endemic and Ethnic Diseases, Ministry of Education, Guizhou Medical University, Guiyang, Guizhou, China.
| | - Jun-Sheng Chen
- Key Laboratory of Endemic and Ethnic Diseases, Laboratory of Molecular Biology, Ministry of Education, Guizhou Medical University, Guiyang, Guizhou, China.
- Key Laboratory of Endemic and Ethnic Diseases, Ministry of Education, Guizhou Medical University, Guiyang, Guizhou, China.
| | - Song Li
- The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China.
| | - Fengning Zhang
- Key Laboratory of Endemic and Ethnic Diseases, Laboratory of Molecular Biology, Ministry of Education, Guizhou Medical University, Guiyang, Guizhou, China.
- Key Laboratory of Endemic and Ethnic Diseases, Ministry of Education, Guizhou Medical University, Guiyang, Guizhou, China.
| | - Jie Deng
- Key Laboratory of Endemic and Ethnic Diseases, Laboratory of Molecular Biology, Ministry of Education, Guizhou Medical University, Guiyang, Guizhou, China.
- Key Laboratory of Endemic and Ethnic Diseases, Ministry of Education, Guizhou Medical University, Guiyang, Guizhou, China.
| | - Ling-Hui Zeng
- Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang Province, School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, China
| | - Jun Tan
- Key Laboratory of Endemic and Ethnic Diseases, Laboratory of Molecular Biology, Ministry of Education, Guizhou Medical University, Guiyang, Guizhou, China.
- Key Laboratory of Endemic and Ethnic Diseases, Ministry of Education, Guizhou Medical University, Guiyang, Guizhou, China.
- Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang Province, School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, China
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Tapias V, González-Andrés P, Peña LF, Barbero A, Núñez L, Villalobos C. Therapeutic Potential of Heterocyclic Compounds Targeting Mitochondrial Calcium Homeostasis and Signaling in Alzheimer's Disease and Parkinson's Disease. Antioxidants (Basel) 2023; 12:1282. [PMID: 37372013 DOI: 10.3390/antiox12061282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 05/24/2023] [Accepted: 06/13/2023] [Indexed: 06/29/2023] Open
Abstract
Alzheimer's disease (AD) and Parkinson's disease (PD) are the two most common neurodegenerative diseases in the elderly. The key histopathological features of these diseases are the presence of abnormal protein aggregates and the progressive and irreversible loss of neurons in specific brain regions. The exact mechanisms underlying the etiopathogenesis of AD or PD remain unknown, but there is extensive evidence indicating that excessive generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS), along with a depleted antioxidant system, mitochondrial dysfunction, and intracellular Ca2+ dyshomeostasis, plays a vital role in the pathophysiology of these neurological disorders. Due to an improvement in life expectancy, the incidence of age-related neurodegenerative diseases has significantly increased. However, there is no effective protective treatment or therapy available but rather only very limited palliative treatment. Therefore, there is an urgent need for the development of preventive strategies and disease-modifying therapies to treat AD/PD. Because dysregulated Ca2+ metabolism drives oxidative damage and neuropathology in these diseases, the identification or development of compounds capable of restoring Ca2+ homeostasis and signaling may provide a neuroprotective avenue for the treatment of neurodegenerative diseases. In addition, a set of strategies to control mitochondrial Ca2+ homeostasis and signaling has been reported, including decreased Ca2+ uptake through voltage-operated Ca2+ channels (VOCCs). In this article, we review the modulatory effects of several heterocyclic compounds on Ca2+ homeostasis and trafficking, as well as their ability to regulate compromised mitochondrial function and associated free-radical production during the onset and progression of AD or PD. This comprehensive review also describes the chemical synthesis of the heterocycles and summarizes the clinical trial outcomes.
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Affiliation(s)
- Victor Tapias
- Unidad de Excelencia Instituto de Biomedicina y Genética Molecular de Valladolid (IBGM), Universidad de Valladolid y Consejo Superior de Investigaciones Científicas (CSIC), 47003 Valladolid, Spain
- Departamento de Bioquímica y Biología Molecular y Fisiología, Facultad de Medicina, Universidad de Valladolid, 47003 Valladolid, Spain
| | - Paula González-Andrés
- Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Valladolid, 47003 Valladolid, Spain
| | - Laura F Peña
- Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Valladolid, 47003 Valladolid, Spain
| | - Asunción Barbero
- Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Valladolid, 47003 Valladolid, Spain
| | - Lucía Núñez
- Unidad de Excelencia Instituto de Biomedicina y Genética Molecular de Valladolid (IBGM), Universidad de Valladolid y Consejo Superior de Investigaciones Científicas (CSIC), 47003 Valladolid, Spain
- Departamento de Bioquímica y Biología Molecular y Fisiología, Facultad de Medicina, Universidad de Valladolid, 47003 Valladolid, Spain
| | - Carlos Villalobos
- Unidad de Excelencia Instituto de Biomedicina y Genética Molecular de Valladolid (IBGM), Universidad de Valladolid y Consejo Superior de Investigaciones Científicas (CSIC), 47003 Valladolid, Spain
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3
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Zhang H, Zhou H, Guo X, Zhang G, Xiao M, Wu S, Jin C, Yang J, Lu X. Cigarette smoke triggers calcium overload in mouse hippocampal neurons via the ΔFOSB-CACNA2D1 axis to impair cognitive performance. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 258:114996. [PMID: 37167740 DOI: 10.1016/j.ecoenv.2023.114996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 03/24/2023] [Accepted: 05/06/2023] [Indexed: 05/13/2023]
Abstract
A growing body of evidence shows that cigarette smoking impairs cognitive performance. The 'Calcium Hypothesis' theory of neuronopathies reveals a critical role of aberrant calcium signaling in compromised cognitive functions. However, the underlying implications of abnormalities in calcium signaling in the neurotoxicity induced by cigarette smoke (CS) have not yet been identified. CACNA2D1, an important auxiliary subunit involved in the composition of voltage-gated calcium channels (VGCCs), was reported to affect the calcium signaling in neurons by facilitating VGCCs-mediated Ca2+ influx. ΔFOSB, an alternatively-spliced product of the Fosb gene, is an activity-dependent transcription factor induced robustly in the brain in response to environmental stimuli such as CS. Interestingly, our preliminary bioinformatics analysis revealed a significant co-expression between ΔFOSB and CACNA2D1 in brain tissues of patients with neurodegenerative diseases characterized by progressive cognitive decline. Therefore, we hypothesized that the activation of the ΔFOSB-CACNA2D1 axis in response to CS exposure might cause dysregulation of calcium homeostasis in hippocampal neurons via VGCCs-mediated Ca2+ influx, thereby contributing to cognitive deficits. To this end, the present study established a CS-induced mouse model of hippocampus-dependent cognitive impairment, in which the activation of the ΔFOSB-CACNA2D1 axis accompanied by severe calcium overload was observed in the mouse hippocampal tissues. More importantly, ΔFOSB knockdown-/overexpression-mediated inactivation/activation of the ΔFOSB-CACNA2D1 axis interdicted/mimicked CS-induced dysregulation of calcium homeostasis followed by severe cellular damage in HT22 mouse hippocampal neurons. Mechanistically speaking, a further ChIP-qPCR assay confirmed the physical interaction between transcription factor ΔFOSB and the Cacna2d1 gene promoter, suggesting a direct transcriptional regulation of the Cacna2d1 gene by ΔFOSB. Overall, our current work aims to deliver a unique insight into the neurotoxic mechanisms induced by CS to explore potential targets for intervention.
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Affiliation(s)
- Hongchao Zhang
- Key Laboratory of Environmental Stress and Chronic Disease Control and Prevention, Ministry of Education, China Medical University, Shenyang 110122, People's Republic of China; Department of Toxicology, School of Public Health, China Medical University, Shenyang 110122, People's Republic of China
| | - Huabin Zhou
- Department of Toxicology, School of Public Health, China Medical University, Shenyang 110122, People's Republic of China
| | - Xianhe Guo
- Department of Toxicology, School of Public Health, China Medical University, Shenyang 110122, People's Republic of China
| | - Guopei Zhang
- Key Laboratory of Environmental Stress and Chronic Disease Control and Prevention, Ministry of Education, China Medical University, Shenyang 110122, People's Republic of China; Department of Toxicology, School of Public Health, China Medical University, Shenyang 110122, People's Republic of China
| | - Mingyang Xiao
- Key Laboratory of Environmental Stress and Chronic Disease Control and Prevention, Ministry of Education, China Medical University, Shenyang 110122, People's Republic of China; Department of Toxicology, School of Public Health, China Medical University, Shenyang 110122, People's Republic of China
| | - Shengwen Wu
- Key Laboratory of Environmental Stress and Chronic Disease Control and Prevention, Ministry of Education, China Medical University, Shenyang 110122, People's Republic of China; Department of Toxicology, School of Public Health, China Medical University, Shenyang 110122, People's Republic of China
| | - Cuihong Jin
- Key Laboratory of Environmental Stress and Chronic Disease Control and Prevention, Ministry of Education, China Medical University, Shenyang 110122, People's Republic of China; Department of Toxicology, School of Public Health, China Medical University, Shenyang 110122, People's Republic of China
| | - Jinghua Yang
- Key Laboratory of Environmental Stress and Chronic Disease Control and Prevention, Ministry of Education, China Medical University, Shenyang 110122, People's Republic of China; Department of Toxicology, School of Public Health, China Medical University, Shenyang 110122, People's Republic of China
| | - Xiaobo Lu
- Key Laboratory of Environmental Stress and Chronic Disease Control and Prevention, Ministry of Education, China Medical University, Shenyang 110122, People's Republic of China; Department of Toxicology, School of Public Health, China Medical University, Shenyang 110122, People's Republic of China.
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Mockett BG, Ryan MM. The therapeutic potential of the neuroactive peptides of soluble amyloid precursor protein-alpha in Alzheimer's disease and related neurological disorders. Semin Cell Dev Biol 2023; 139:93-101. [PMID: 35654665 DOI: 10.1016/j.semcdb.2022.05.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Revised: 05/15/2022] [Accepted: 05/16/2022] [Indexed: 12/31/2022]
Abstract
Soluble amyloid precursor protein-alpha (sAPPα) is a multi-functional brain-derived protein that has neuroprotective, neurogenic and neurotropic properties. Moreover, it is known to facilitate synaptic function and promote neural repair. These properties suggest sAPPα may be useful as a therapeutic agent for the treatment of neurological diseases characterized by synaptic failure and neuronal loss, such as occurs in Alzheimer's disease, and for neural repair following traumatic brain injury and stroke. However, sAPPα's relatively large size and the difficulty of ongoing delivery of therapeutics to the brain mean this is not currently practicable. Importantly, however, sAPPα is composed of several neuroactive domains that each possess properties that collectively are remarkably similar to those of sAPPα itself. Here, we review the molecular structure of sAPPα and identify the domains that contribute to its overall functionality. Four peptide motifs present as possible targets for therapeutic development. We review their physiochemical and neuroactive properties, both within sAPPα and as isolated peptides, and discuss their potential for future development as multipurpose therapeutic agents for the treatment of Alzheimer's disease and other disorders of neuronal function. Further, we discuss the role of heparin binding sites, found within sAPPα's structure and overlapping with the neuroactive domains, as sites for interactions with effector proteins and synaptic receptors. The potential role of the neuroactive peptides known as Cationic Arginine-Rich Peptides (CARPs) as neuroprotective motifs is also reviewed. Mechanisms of peptide delivery to the brain are briefly discussed. Finally, we summarise the potential benefits and pitfalls of using the isolated peptides, either individually or in combination, for the treatment of neurological diseases.
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Affiliation(s)
- Bruce G Mockett
- Department of Psychology, University of Otago, PO Box 56, Dunedin, New Zealand; Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - Margaret M Ryan
- Department of Anatomy, School of Biomedical Sciences, University of Otago, PO Box 56, Dunedin, New Zealand; Brain Health Research Centre, University of Otago, Dunedin, New Zealand.
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Baltissen D, Bold CS, Rehra L, Banićević M, Fricke J, Just J, Ludewig S, Buchholz CJ, Korte M, Müller UC. APPsα rescues CDK5 and GSK3β dysregulation and restores normal spine density in Tau transgenic mice. Front Cell Neurosci 2023; 17:1106176. [PMID: 36779015 PMCID: PMC9909437 DOI: 10.3389/fncel.2023.1106176] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 01/02/2023] [Indexed: 01/27/2023] Open
Abstract
The Tau protein can be phosphorylated by numerous kinases. In Alzheimer's disease (AD) hyperphosphorylated Tau species accumulate as neurofibrillary tangles that constitute a major hallmark of AD. AD is further characterized by extracellular Aβ plaques, derived from the β-amyloid precursor protein APP. Whereas Aβ is produced by amyloidogenic APP processing, APP processing along the competing non-amyloidogenic pathway results in the secretion of neurotrophic and synaptotrophic APPsα. Recently, we demonstrated that APPsα has therapeutic effects in transgenic AD model mice and rescues Aβ-dependent impairments. Here, we examined the potential of APPsα to regulate two major Tau kinases, GSK3β and CDK5 in THY-Tau22 mice, a widely used mouse model of tauopathy. Immunohistochemistry revealed a dramatic increase in pathologically phosphorylated (AT8 and AT180) or misfolded Tau species (MC1) in the hippocampus of THY-Tau22 mice between 3 and 12 months of age. Using a highly sensitive radioactive kinase assay with recombinant human Tau as a substrate and immunoblotting, we demonstrate an increase in GSK3β and CDK5 activity in the hippocampus of THY-Tau22 mice. Interestingly, AAV-mediated intracranial expression of APPsα in THY-Tau22 mice efficiently restored normal GSK3β and CDK5 activity. Western blot analysis revealed upregulation of the CDK5 regulatory proteins p35 and p25, indicating CDK5 hyperactivation in THY-Tau22 mice. Strikingly, AAV-APPsα rescued p25 upregulation to wild-type levels even at stages of advanced Tau pathology. Sarkosyl fractionation used to study the abundance of soluble and insoluble phospho-Tau species revealed increased soluble AT8-Tau and decreased insoluble AT100-Tau species upon AAV-APPsα injection. Moreover, AAV-APPsα reduced misfolded (MC1) Tau species, particularly in somatodendritic compartments of CA1 pyramidal neurons. Finally, we show that AAV-APPsα upregulated PSD95 expression and rescued deficits in spine density of THY-Tau22 mice. Together our findings suggest that APPsα holds therapeutic potential to mitigate Tau-induced pathology.
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Affiliation(s)
- Danny Baltissen
- Department of Functional Genomics, Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Heidelberg, Germany
| | - Charlotte S. Bold
- Department of Functional Genomics, Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Heidelberg, Germany
| | - Lena Rehra
- Department of Functional Genomics, Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Heidelberg, Germany
| | - Marija Banićević
- Department of Functional Genomics, Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Heidelberg, Germany
| | - Justus Fricke
- Department of Functional Genomics, Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Heidelberg, Germany
| | - Jennifer Just
- Department of Cellular Neurobiology, Zoological Institute, Technical University of Braunschweig, Braunschweig, Germany
| | - Susann Ludewig
- Department of Cellular Neurobiology, Zoological Institute, Technical University of Braunschweig, Braunschweig, Germany
| | - Christian J. Buchholz
- Department of Molecular Biotechnology and Gene Therapy, Paul-Ehrlich-Institut, Langen, Germany
| | - Martin Korte
- Department of Cellular Neurobiology, Zoological Institute, Technical University of Braunschweig, Braunschweig, Germany,Helmholtz Centre for Infection Research, Neuroinflammation and Neurodegeneration Group, Braunschweig, Germany
| | - Ulrike C. Müller
- Department of Functional Genomics, Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Heidelberg, Germany,*Correspondence: Ulrike C. Müller,
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Li Y, Wang JZ, Deng YM, Wang K, Yang L, Long C. Amyloid-β Protein Precursor Regulates Electrophysiological Properties in the Hippocampus via Altered Kv1.4 Expression and Function in Mice. J Alzheimers Dis 2023; 92:1241-1256. [PMID: 36872774 DOI: 10.3233/jad-220606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
Abstract
BACKGROUND Amyloid-β protein precursor (AβPP) is enriched in neurons. However, the mechanism underlying AβPP regulation of neuronal activity is poorly understood. Potassium channels are critically involved in neuronal excitability. In hippocampus, A-type potassium channels are highly expressed and involved in determining neuronal spiking. OBJECTIVE We explored hippocampal local field potential (LFP) and spiking in the presence and absence of AβPP, and the potential involvement of an A-type potassium channel. METHODS We used in vivo extracellular recording and whole-cell patch-clamp recording to determine neuronal activity, current density of A-type potassium currents, and western blot to detect changes in related protein levels. RESULTS Abnormal LFP was observed in AβPP-/- mice, including reduced beta and gamma power, and increased epsilon and ripple power. The firing rate of glutamatergic neurons reduced significantly, in line with an increased action potential rheobase. Given that A-type potassium channels regulate neuronal firing, we measured the protein levels and function of two major A-type potassium channels and found that the post-transcriptional level of Kv1.4, but not Kv4.2, was significantly increased in the AβPP-/- mice. This resulted in a marked increase in the peak time of A-type transient outward potassium currents in both glutamatergic and gamma-aminobutyric acid-ergic (GABAergic) neurons. Furthermore, a mechanistic experiment using human embryonic kidney 293 (HEK293) cells revealed that the AβPP deficiency-induced increase in Kv1.4 may not involve protein-protein interaction between AβPP and Kv1.4. CONCLUSION This study suggests that AβPP modulates neuronal firing and oscillatory activity in the hippocampus, and Kv1.4 may be involved in mediating the modulation.
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Affiliation(s)
- Yi Li
- South China Normal University-Panyu Central Hospital Joint Laboratory of Translational Medical Research, Panyu Central Hospital, Guangzhou, China
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Jin-Zhao Wang
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Yue-Ming Deng
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Kun Wang
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Li Yang
- School of Life Sciences, Guangzhou University, Guangzhou, China
| | - Cheng Long
- South China Normal University-Panyu Central Hospital Joint Laboratory of Translational Medical Research, Panyu Central Hospital, Guangzhou, China
- School of Life Sciences, South China Normal University, Guangzhou, China
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Mercan D, Heneka MT. The Contribution of the Locus Coeruleus-Noradrenaline System Degeneration during the Progression of Alzheimer's Disease. BIOLOGY 2022; 11:biology11121822. [PMID: 36552331 PMCID: PMC9775634 DOI: 10.3390/biology11121822] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 12/07/2022] [Accepted: 12/08/2022] [Indexed: 12/23/2022]
Abstract
Alzheimer's disease (AD), which is characterized by extracellular accumulation of amyloid-beta peptide and intracellular aggregation of hyperphosphorylated tau, is the most common form of dementia. Memory loss, cognitive decline and disorientation are the ultimate consequences of neuronal death, synapse loss and neuroinflammation in AD. In general, there are many brain regions affected but neuronal loss in the locus coeruleus (LC) is one of the earliest indicators of neurodegeneration in AD. Since the LC is the main source of noradrenaline (NA) in the brain, degeneration of the LC in AD leads to decreased NA levels, causing increased neuroinflammation, enhanced amyloid and tau burden, decreased phagocytosis and impairment in cognition and long-term synaptic plasticity. In this review, we summarized current findings on the locus coeruleus-noradrenaline system and consequences of its dysfunction which is now recognized as an important contributor to AD progression.
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Affiliation(s)
- Dilek Mercan
- German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany
| | - Michael Thomas Heneka
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, 4365 Esch-sur-Alzette, Luxembourg
- Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA 01605, USA
- Correspondence: ; Tel.: +352-46-66-44-6922 or +352-62-17-12-820
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Bold CS, Baltissen D, Ludewig S, Back MK, Just J, Kilian L, Erdinger S, Banicevic M, Rehra L, Almouhanna F, Nigri M, Wolfer DP, Spilger R, Rohr K, Kann O, Buchholz CJ, von Engelhardt J, Korte M, Müller UC. APPsα Rescues Tau-Induced Synaptic Pathology. J Neurosci 2022; 42:5782-5802. [PMID: 35667850 PMCID: PMC9302470 DOI: 10.1523/jneurosci.2200-21.2022] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 04/06/2022] [Accepted: 05/22/2022] [Indexed: 01/22/2023] Open
Abstract
Alzheimer's disease (AD) is histopathologically characterized by Aβ plaques and the accumulation of hyperphosphorylated Tau species, the latter also constituting key hallmarks of primary tauopathies. Whereas Aβ is produced by amyloidogenic APP processing, APP processing along the competing nonamyloidogenic pathway results in the secretion of neurotrophic and synaptotrophic APPsα. Recently, we demonstrated that APPsα has therapeutic effects in transgenic AD model mice and rescues Aβ-dependent impairments. Here, we examined the potential of APPsα to mitigate Tau-induced synaptic deficits in P301S mice (both sexes), a widely used mouse model of tauopathy. Analysis of synaptic plasticity revealed an aberrantly increased LTP in P301S mice that could be normalized by acute application of nanomolar amounts of APPsα to hippocampal slices, indicating a homeostatic function of APPsα on a rapid time scale. Further, AAV-mediated in vivo expression of APPsα restored normal spine density of CA1 neurons even at stages of advanced Tau pathology not only in P301S mice, but also in independent THY-Tau22 mice. Strikingly, when searching for the mechanism underlying aberrantly increased LTP in P301S mice, we identified an early and progressive loss of major GABAergic interneuron subtypes in the hippocampus of P301S mice, which may lead to reduced GABAergic inhibition of principal cells. Interneuron loss was paralleled by deficits in nest building, an innate behavior highly sensitive to hippocampal impairments. Together, our findings indicate that APPsα has therapeutic potential for Tau-mediated synaptic dysfunction and suggest that loss of interneurons leads to disturbed neuronal circuits that compromise synaptic plasticity as well as behavior.SIGNIFICANCE STATEMENT Our findings indicate, for the first time, that APPsα has the potential to rescue Tau-induced spine loss and abnormal synaptic plasticity. Thus, APPsα might have therapeutic potential not only because of its synaptotrophic functions, but also its homeostatic capacity for neuronal network activity. Hence, APPsα is one of the few molecules which has proven therapeutic effects in mice, both for Aβ- and Tau-dependent synaptic impairments and might therefore have therapeutic potential for patients suffering from AD or primary tauopathies. Furthermore, we found in P301S mice a pronounced reduction of inhibitory interneurons as the earliest pathologic event preceding the accumulation of hyperphosphorylated Tau species. This loss of interneurons most likely disturbs neuronal circuits that are important for synaptic plasticity and behavior.
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Affiliation(s)
- Charlotte S Bold
- Institute of Pharmacy and Molecular Biotechnology, Ruprecht Karls Universität Heidelberg, Heidelberg, 69120, Germany
| | - Danny Baltissen
- Institute of Pharmacy and Molecular Biotechnology, Ruprecht Karls Universität Heidelberg, Heidelberg, 69120, Germany
| | - Susann Ludewig
- TU Braunschweig, Zoological Institute, Braunschweig, 38106, Germany
- Helmholtz Centre for Infection Research, Neuroinflammation and Neurodegeneration Group, Braunschweig, 38124, Germany
| | - Michaela K Back
- Institute of Pathophysiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, 55128, Germany
| | - Jennifer Just
- TU Braunschweig, Zoological Institute, Braunschweig, 38106, Germany
| | - Lara Kilian
- Institute of Pharmacy and Molecular Biotechnology, Ruprecht Karls Universität Heidelberg, Heidelberg, 69120, Germany
| | - Susanne Erdinger
- Institute of Pharmacy and Molecular Biotechnology, Ruprecht Karls Universität Heidelberg, Heidelberg, 69120, Germany
| | - Marija Banicevic
- Institute of Pharmacy and Molecular Biotechnology, Ruprecht Karls Universität Heidelberg, Heidelberg, 69120, Germany
| | - Lena Rehra
- Institute of Pharmacy and Molecular Biotechnology, Ruprecht Karls Universität Heidelberg, Heidelberg, 69120, Germany
| | - Fadi Almouhanna
- Institute of Physiology and Pathophysiology, Ruprecht Karls Universität Heidelberg, Heidelberg, 69120, Germany
| | - Martina Nigri
- Institute of Anatomy, University of Zurich, Zurich, 8057, Switzerland
| | - David P Wolfer
- Institute of Anatomy, University of Zurich, Zurich, 8057, Switzerland
- Institute of Human Movement Sciences and Sport, ETH Zurich, Zurich, Switzerland
| | - Roman Spilger
- BioQuant Center, Institute of Pharmacy and Molecular Biotechnology, Ruprecht Karls Universität Heidelberg and DKFZ, Heidelberg, 69120, Germany
| | - Karl Rohr
- BioQuant Center, Institute of Pharmacy and Molecular Biotechnology, Ruprecht Karls Universität Heidelberg and DKFZ, Heidelberg, 69120, Germany
| | - Oliver Kann
- Institute of Physiology and Pathophysiology, Ruprecht Karls Universität Heidelberg, Heidelberg, 69120, Germany
| | | | - Jakob von Engelhardt
- Institute of Pathophysiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, 55128, Germany
| | - Martin Korte
- TU Braunschweig, Zoological Institute, Braunschweig, 38106, Germany
- Helmholtz Centre for Infection Research, Neuroinflammation and Neurodegeneration Group, Braunschweig, 38124, Germany
| | - Ulrike C Müller
- Institute of Pharmacy and Molecular Biotechnology, Ruprecht Karls Universität Heidelberg, Heidelberg, 69120, Germany
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Papazoglou A, Arshaad MI, Henseler C, Daubner J, Broich K, Hescheler J, Ehninger D, Haenisch B, Weiergräber M. Ca v3 T-Type Voltage-Gated Ca 2+ Channels and the Amyloidogenic Environment: Pathophysiology and Implications on Pharmacotherapy and Pharmacovigilance. Int J Mol Sci 2022; 23:ijms23073457. [PMID: 35408817 PMCID: PMC8998330 DOI: 10.3390/ijms23073457] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Revised: 03/17/2022] [Accepted: 03/18/2022] [Indexed: 12/07/2022] Open
Abstract
Voltage-gated Ca2+ channels (VGCCs) were reported to play a crucial role in neurotransmitter release, dendritic resonance phenomena and integration, and the regulation of gene expression. In the septohippocampal system, high- and low-voltage-activated (HVA, LVA) Ca2+ channels were shown to be involved in theta genesis, learning, and memory processes. In particular, HVA Cav2.3 R-type and LVA Cav3 T-type Ca2+ channels are expressed in the medial septum-diagonal band of Broca (MS-DBB), hippocampal interneurons, and pyramidal cells, and ablation of both channels was proven to severely modulate theta activity. Importantly, Cav3 Ca2+ channels contribute to rebound burst firing in septal interneurons. Consequently, functional impairment of T-type Ca2+ channels, e.g., in null mutant mouse models, caused tonic disinhibition of the septohippocampal pathway and subsequent enhancement of hippocampal theta activity. In addition, impairment of GABA A/B receptor transcription, trafficking, and membrane translocation was observed within the septohippocampal system. Given the recent findings that amyloid precursor protein (APP) forms complexes with GABA B receptors (GBRs), it is hypothesized that T-type Ca2+ current reduction, decrease in GABA receptors, and APP destabilization generate complex functional interdependence that can constitute a sophisticated proamyloidogenic environment, which could be of potential relevance in the etiopathogenesis of Alzheimer’s disease (AD). The age-related downregulation of T-type Ca2+ channels in humans goes together with increased Aβ levels that could further inhibit T-type channels and aggravate the proamyloidogenic environment. The mechanistic model presented here sheds new light on recent reports about the potential risks of T-type Ca2+ channel blockers (CCBs) in dementia, as observed upon antiepileptic drug application in the elderly.
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Affiliation(s)
- Anna Papazoglou
- Experimental Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany; (A.P.); (M.I.A.); (C.H.); (J.D.)
| | - Muhammad Imran Arshaad
- Experimental Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany; (A.P.); (M.I.A.); (C.H.); (J.D.)
| | - Christina Henseler
- Experimental Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany; (A.P.); (M.I.A.); (C.H.); (J.D.)
| | - Johanna Daubner
- Experimental Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany; (A.P.); (M.I.A.); (C.H.); (J.D.)
| | - Karl Broich
- Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany; (K.B.); (B.H.)
| | - Jürgen Hescheler
- Faculty of Medicine, Institute of Neurophysiology, University of Cologne, Robert-Koch-Str. 39, 50931 Cologne, Germany;
- Center of Physiology and Pathophysiology, Faculty of Medicine, University of Cologne, Robert-Koch-Str. 39, 50931 Cologne, Germany
| | - Dan Ehninger
- Translational Biogerontology, German Center for Neurodegenerative Diseases (Deutsches Zentrum für Neurodegenerative Erkrankungen, DZNE), Venusberg-Campus 1/99, 53127 Bonn, Germany;
- German Center for Neurodegenerative Diseases (Deutsches Zentrum für Neurodegenerative Erkrankungen, DZNE), Venusberg-Campus 1/99, 53127 Bonn, Germany
| | - Britta Haenisch
- Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany; (K.B.); (B.H.)
- German Center for Neurodegenerative Diseases (Deutsches Zentrum für Neurodegenerative Erkrankungen, DZNE), Venusberg-Campus 1/99, 53127 Bonn, Germany
- Center for Translational Medicine, Medical Faculty, University of Bonn, 53113 Bonn, Germany
| | - Marco Weiergräber
- Experimental Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany; (A.P.); (M.I.A.); (C.H.); (J.D.)
- Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany; (K.B.); (B.H.)
- Faculty of Medicine, Institute of Neurophysiology, University of Cologne, Robert-Koch-Str. 39, 50931 Cologne, Germany;
- Center of Physiology and Pathophysiology, Faculty of Medicine, University of Cologne, Robert-Koch-Str. 39, 50931 Cologne, Germany
- Correspondence: ; Tel.: +49-228-99307-4358
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10
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Panayotacopoulou MT, Papageorgiou I, Pagida M, Katsogridaki AE, Chrysanthou-Piterou M, Valous NA, Halama N, Patsouris E, Konstantinidou AE. Microglia Activation in the Midbrain of the Human Neonate: The Effect of Perinatal Hypoxic-Ischemic Injury. J Neuropathol Exp Neurol 2022; 81:208-224. [PMID: 35092294 DOI: 10.1093/jnen/nlab135] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Perinatal hypoxia-ischemia (PHI) is a major risk factor for the development of neuropsychiatric deficits later in life. We previously reported that after prolonged PHI, the dopaminergic neurons of the human neonate showed a dramatic reduction of tyrosine hydroxylase (TH) in the substantia nigra, without important signs of neuronal degeneration despite the significant reduction in their cell size. Since microglia activation could precede neuronal death, we now investigated 2 microglia activation markers, ionized calcium-binding adapter molecule 1 (Iba1), and the phagocytosis marker Cd68. The highest Iba1 immunoreactivity was found in neonates with neuropathological lesions of severe/abrupt PHI, while the lowest in subjects with moderate/prolonged or older PHI. Subjects with very severe/prolonged or chronic PHI showed an increased Iba1 expression and very activated microglial morphology. Heavy attachment of microglia on TH neurons and remarkable expression of Cd68 were also observed indicating phagocytosis in this group. Females appear to express more Iba1 than males, suggesting a gender difference in microglia maturation and immune reactivity after PHI insult. PHI-induced microglial "priming" during the sensitive for brain development perinatal/neonatal period, in combination with genetic or other epigenetic factors, could predispose the survivors to neuropsychiatric disorders later in life, possibly through a sexually dimorphic way.
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Affiliation(s)
- Maria T Panayotacopoulou
- From the Department of Psychiatry, National and Kapodistrian University of Athens, Athens, Greece (MTP, MP, AEK, MC-P).,University Mental Health, Neurosciences and Precision Medicine Research Institute "Kostas Stefanis", National and Kapodistrian University of Athens, Athens, Greece (MTP, MP, AEK, MC-P, EP)
| | - Ismini Papageorgiou
- Institute for Diagnostic and Interventional Radiology, University Hospital of Jena, Jena, Germany (IP).,Institute of Radiology, Südharz Hospital Nordhausen, Nordhausen, Germany (IP)
| | - Marianna Pagida
- From the Department of Psychiatry, National and Kapodistrian University of Athens, Athens, Greece (MTP, MP, AEK, MC-P).,University Mental Health, Neurosciences and Precision Medicine Research Institute "Kostas Stefanis", National and Kapodistrian University of Athens, Athens, Greece (MTP, MP, AEK, MC-P, EP)
| | - Alexandra E Katsogridaki
- From the Department of Psychiatry, National and Kapodistrian University of Athens, Athens, Greece (MTP, MP, AEK, MC-P).,University Mental Health, Neurosciences and Precision Medicine Research Institute "Kostas Stefanis", National and Kapodistrian University of Athens, Athens, Greece (MTP, MP, AEK, MC-P, EP)
| | - Margarita Chrysanthou-Piterou
- From the Department of Psychiatry, National and Kapodistrian University of Athens, Athens, Greece (MTP, MP, AEK, MC-P).,University Mental Health, Neurosciences and Precision Medicine Research Institute "Kostas Stefanis", National and Kapodistrian University of Athens, Athens, Greece (MTP, MP, AEK, MC-P, EP)
| | - Nektarios A Valous
- Applied Tumor Immunity Clinical Cooperation Unit, National Center for Tumor Diseases (NCT), German Cancer Research Center (DKFZ), Heidelberg, Germany (NAV)
| | - Niels Halama
- Department of Medical Oncology, National Center for Tumor Diseases (NCT), Heidelberg University Hospital (UKHD), Heidelberg, Germany (NH).,Division of Translational Immunotherapy, German Cancer Research Center (DKFZ), Heidelberg, Germany (NH)
| | - Efstratios Patsouris
- University Mental Health, Neurosciences and Precision Medicine Research Institute "Kostas Stefanis", National and Kapodistrian University of Athens, Athens, Greece (MTP, MP, AEK, MC-P, EP).,1st Department of Pathology, National and Kapodistrian University of Athens, Athens, Greece (EP, AEK)
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11
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Hambali A, Kumar J, Hashim NFM, Maniam S, Mehat MZ, Cheema MS, Mustapha M, Adenan MI, Stanslas J, Hamid HA. Hypoxia-Induced Neuroinflammation in Alzheimer's Disease: Potential Neuroprotective Effects of Centella asiatica. Front Physiol 2021; 12:712317. [PMID: 34721056 PMCID: PMC8551388 DOI: 10.3389/fphys.2021.712317] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 09/13/2021] [Indexed: 12/11/2022] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder that is characterised by the presence of extracellular beta-amyloid fibrillary plaques and intraneuronal neurofibrillary tau tangles in the brain. Recurring failures of drug candidates targeting these pathways have prompted research in AD multifactorial pathogenesis, including the role of neuroinflammation. Triggered by various factors, such as hypoxia, neuroinflammation is strongly linked to AD susceptibility and/or progression to dementia. Chronic hypoxia induces neuroinflammation by activating microglia, the resident immune cells in the brain, along with an increased in reactive oxygen species and pro-inflammatory cytokines, features that are common to many degenerative central nervous system (CNS) disorders. Hence, interests are emerging on therapeutic agents and plant derivatives for AD that target the hypoxia-neuroinflammation pathway. Centella asiatica is one of the natural products reported to show neuroprotective effects in various models of CNS diseases. Here, we review the complex hypoxia-induced neuroinflammation in the pathogenesis of AD and the potential application of Centella asiatica as a therapeutic agent in AD or dementia.
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Affiliation(s)
- Aqilah Hambali
- Department of Human Anatomy, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Malaysia
| | - Jaya Kumar
- Department of Physiology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Cheras, Malaysia
| | - Nur Fariesha Md Hashim
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Malaysia
| | - Sandra Maniam
- Department of Human Anatomy, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Malaysia
| | - Muhammad Zulfadli Mehat
- Department of Human Anatomy, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Malaysia
| | - Manraj Singh Cheema
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Malaysia
| | - Muzaimi Mustapha
- Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Malaysia
| | | | - Johnson Stanslas
- Department of Medicine, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Malaysia
| | - Hafizah Abdul Hamid
- Department of Human Anatomy, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Malaysia
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12
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Transient Oxygen-Glucose Deprivation Causes Region- and Cell Type-Dependent Functional Deficits in the Mouse Hippocampus In Vitro. eNeuro 2021; 8:ENEURO.0221-21.2021. [PMID: 34475264 PMCID: PMC8482850 DOI: 10.1523/eneuro.0221-21.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/21/2021] [Accepted: 07/03/2021] [Indexed: 01/11/2023] Open
Abstract
Neurons are highly vulnerable to conditions of hypoxia-ischemia (HI) such as stroke or transient ischemic attacks. Recovery of cognitive and behavioral functions requires re-emergence of coordinated network activity, which, in turn, relies on the well-orchestrated interaction of pyramidal cells (PYRs) and interneurons. We therefore modelled HI in the mouse hippocampus, a particularly vulnerable region showing marked loss of PYR and fast-spiking interneurons (FSIs) after hypoxic-ischemic insults. Transient oxygen-glucose deprivation (OGD) in ex vivo hippocampal slices led to a rapid loss of neuronal activity and spontaneous network oscillations (sharp wave-ripple complexes; SPW-Rs), and to the occurrence of a spreading depolarization. Following reperfusion, both SPW-R and neuronal spiking resumed, but FSI activity remained strongly reduced compared with PYR. Whole-cell recordings in CA1 PYR revealed, however, a similar reduction of both EPSCs and IPSCs, leaving inhibition-excitation (I/E) balance unaltered. At the network level, SPW-R incidence was strongly reduced and the remaining network events showed region-specific changes including reduced ripple energy in CA3 and increased ripple frequency in CA1. Together, our data show that transient hippocampal energy depletion results in severe functional alterations at the cellular and network level. While I/E balance is maintained, synaptic activity, interneuron spiking and coordinated network patterns remain reduced. Such alterations may be network-level correlates of cognitive and functional deficits after cerebral HI.
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13
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Ludewig S, Herrmann U, Michaelsen-Preusse K, Metzdorf K, Just J, Bold C, Müller UC, Korte M. APPsα rescues impaired Ca 2+ homeostasis in APP- and APLP2-deficient hippocampal neurons. Proc Natl Acad Sci U S A 2021; 118:e2011506118. [PMID: 34172567 PMCID: PMC8256088 DOI: 10.1073/pnas.2011506118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Alterations in Ca2+ homeostasis have been reported in several in vitro and in vivo studies using mice expressing the Alzheimer's disease-associated transgenes, presenilin and the amyloid precursor protein (APP). While intense research focused on amyloid-β-mediated functions on neuronal Ca2+ handling, the physiological role of APP and its close homolog APLP2 is still not fully clarified. We now elucidate a mechanism to show how APP and its homolog APLP2 control neuronal Ca2+ handling and identify especially the ectodomain APPsα as an essential regulator of Ca2+ homeostasis. Importantly, we demonstrate that the loss of APP and APLP2, but not APLP2 alone, impairs Ca2+ handling, the refill of the endoplasmic reticulum Ca2+ stores, and synaptic plasticity due to altered function and expression of the SERCA-ATPase and expression of store-operated Ca2+ channel-associated proteins Stim1 and Stim2. Long-term AAV-mediated expression of APPsα, but not acute application of the recombinant protein, restored physiological Ca2+ homeostasis and synaptic plasticity in APP/APLP2 cDKO cultures. Overall, our analysis reveals an essential role of the APP family and especially of the ectodomain APPsα in Ca2+ homeostasis, thereby highlighting its therapeutic potential.
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Affiliation(s)
- Susann Ludewig
- Department of Cellular Neurobiology Zoological Institute, Technische Universität Braunschweig, 38106 Braunschweig, Germany
- Neuroinflammation and Neurodegeneration, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
| | - Ulrike Herrmann
- Department of Cellular Neurobiology Zoological Institute, Technische Universität Braunschweig, 38106 Braunschweig, Germany
| | - Kristin Michaelsen-Preusse
- Department of Cellular Neurobiology Zoological Institute, Technische Universität Braunschweig, 38106 Braunschweig, Germany
| | - Kristin Metzdorf
- Department of Cellular Neurobiology Zoological Institute, Technische Universität Braunschweig, 38106 Braunschweig, Germany
- Neuroinflammation and Neurodegeneration, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
| | - Jennifer Just
- Department of Cellular Neurobiology Zoological Institute, Technische Universität Braunschweig, 38106 Braunschweig, Germany
| | - Charlotte Bold
- Department of Functional Genomics, Institute for Pharmacy and Molecular Biotechnology, Heidelberg University, 69120 Heidelberg, Germany
| | - Ulrike C Müller
- Department of Functional Genomics, Institute for Pharmacy and Molecular Biotechnology, Heidelberg University, 69120 Heidelberg, Germany
| | - Martin Korte
- Department of Cellular Neurobiology Zoological Institute, Technische Universität Braunschweig, 38106 Braunschweig, Germany;
- Neuroinflammation and Neurodegeneration, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
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14
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Durán-Carabali LE, Odorcyk FK, Greggio S, Venturin GT, Sanches EF, Schu GG, Carvalho AS, Pedroso TA, de Sá Couto-Pereira N, Da Costa JC, Dalmaz C, Zimmer ER, Netto CA. Pre- and early postnatal enriched environmental experiences prevent neonatal hypoxia-ischemia late neurodegeneration via metabolic and neuroplastic mechanisms. J Neurochem 2020; 157:1911-1929. [PMID: 33098090 DOI: 10.1111/jnc.15221] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 10/04/2020] [Accepted: 10/19/2020] [Indexed: 12/17/2022]
Abstract
Prenatal and early postnatal periods are important for brain development and neural function. Neonatal insults such as hypoxia-ischemia (HI) causes prolonged neural and metabolic dysregulation, affecting central nervous system maturation. There is evidence that brain hypometabolism could increase the risk of adult-onset neurodegenerative diseases. However, the impact of non-pharmacologic strategies to attenuate HI-induced brain glucose dysfunction is still underexplored. This study investigated the long-term effects of early environmental enrichment in metabolic, cell, and functional responses after neonatal HI. Thereby, male Wistar rats were divided according to surgical procedure, sham, and HI (performed at postnatal day 3), and the allocation to standard (SC) or enriched condition (EC) during gestation and lactation periods. In-vivo cerebral metabolism was assessed by means of [18 F]-FDG micro-positron emission tomography, and cognitive, biochemical, and histological analyses were performed in adulthood. Our findings reveal that HI causes a reduction in glucose metabolism and glucose transporter levels as well as hyposynchronicity in metabolic brain networks. However, EC during prenatal or early postnatal period attenuated these metabolic disturbances. A positive correlation was observed between [18 F]-FDG values and volume ratios in adulthood, indicating that preserved tissue by EC is metabolically active. EC promotes better cognitive scores, as well as down-regulation of amyloid precursor protein in the parietal cortex and hippocampus of HI animals. Furthermore, growth-associated protein 43 was up-regulated in the cortex of EC animals. Altogether, results presented support that EC during gestation and lactation period can reduce HI-induced impairments that may contribute to functional decline and progressive late neurodegeneration.
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Affiliation(s)
- Luz Elena Durán-Carabali
- Graduate Program in Biological Sciences: Physiology, Instituto de Ciências Básicas da Saúde (ICBS), Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Felipe Kawa Odorcyk
- Graduate Program in Biological Sciences: Physiology, Instituto de Ciências Básicas da Saúde (ICBS), Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Samuel Greggio
- Preclinical Research Center, Brain Institute (BraIns) of Rio Grande do Sul, Porto Alegre, Brazil
| | | | - Eduardo Farias Sanches
- Graduate Program in Biological Sciences: Biochemistry, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Guilherme Garcia Schu
- Graduate Program in Biological Sciences: Biochemistry, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Andrey Soares Carvalho
- Graduate Program in Biological Sciences: Neuroscience, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Thales Avila Pedroso
- Department of Biochemistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Natividade de Sá Couto-Pereira
- Graduate Program in Biological Sciences: Neuroscience, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Jaderson Costa Da Costa
- Preclinical Research Center, Brain Institute (BraIns) of Rio Grande do Sul, Porto Alegre, Brazil
| | - Carla Dalmaz
- Graduate Program in Biological Sciences: Biochemistry, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Graduate Program in Biological Sciences: Neuroscience, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Department of Biochemistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Eduardo Rigon Zimmer
- Graduate Program in Biological Sciences: Pharmacology and Therapeutics, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Department of Pharmacology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Carlos Alexandre Netto
- Graduate Program in Biological Sciences: Physiology, Instituto de Ciências Básicas da Saúde (ICBS), Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Graduate Program in Biological Sciences: Biochemistry, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Department of Biochemistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
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15
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Alzu'bi A, Clowry GJ. Multiple Origins of Secretagogin Expressing Cortical GABAergic Neuron Precursors in the Early Human Fetal Telencephalon. Front Neuroanat 2020; 14:61. [PMID: 32982702 PMCID: PMC7492523 DOI: 10.3389/fnana.2020.00061] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 08/10/2020] [Indexed: 01/31/2023] Open
Abstract
Secretagogin (SCGN) which acts as a calcium signaling sensor, has previously been shown to be expressed by a substantial population of cortical GABAergic neurons at mid-gestation in humans but not in mice. The present study traced SCGN expression in cortical GABAergic neurons in human fetal forebrain from earlier stages than previously studied. Multiple potential origins of SCGN-expressing neurons were identified in the caudal ganglionic eminence (CGE) lateral ganglionic eminence (LGE) septum and preoptic area; these cells largely co-expressed SP8 but not the medial ganglionic eminence marker LHX6. They followed various migration routes to reach their target regions in the neocortex, insular and olfactory cortex (OC) and olfactory bulbs. A robust increase in the number of SCGN-expressing GABAergic cortical neurons was observed in the midgestational period; 58% of DLX2+ neurons expressed SCGN in the cortical wall at 19 post-conceptional weeks (PCW), a higher proportion than expressed calretinin, a marker for GABAergic neurons of LGE/CGE origin. Furthermore, although most SCGN+ neurons co-expressed calretinin in the cortical plate (CP) and deeper layers, in the marginal zone (MZ) SCGN+ and calretinin+ cells formed separate populations. In the adult mouse, it has previously been shown that in the rostral migratory stream (RMS), SCGN, annexin V (ANXA5), and matrix metalloprotease 2 (MMP2) are co-expressed forming a functioning complex that exocytoses MMP2 in response to calcium. In the present study, ANXA5 showed widespread expression throughout the cortical wall, although MMP2 expression was very largely limited to the CP. We found co-expression of these proteins in some SCGN+ neurons in the subventricular zones (SVZ) suggesting a limited role for these cells in remodeling the extracellular matrix, perhaps during cell migration.
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Affiliation(s)
- Ayman Alzu'bi
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom.,Department of Basic Medical Sciences, Faculty of Medicine, Yarmouk University, Irbid, Jordan
| | - Gavin J Clowry
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
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16
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Chatzistavraki M, Papazafiri P, Efthimiopoulos S. Amyloid-β Protein Precursor Regulates Depolarization-Induced Calcium-Mediated Synaptic Signaling in Brain Slices. J Alzheimers Dis 2020; 76:1121-1133. [PMID: 32597808 DOI: 10.3233/jad-200290] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Coordinated calcium influx upon neuronal depolarization activates pathways that phosphorylate CaMKII, ERKs, and the transcription factor CREB and, therefore, expression of pro-survival and neuroprotective genes. Recent evidence indicates that amyloid-β protein precursor (AβPP) is trafficked to synapses and promotes their formation. At the synapse, AβPP interacts with synaptic proteins involved in vesicle exocytosis and affects calcium channel function. OBJECTIVE Herein, we examined the role of AβPP in depolarization-induced calcium-mediated signaling using acute cerebral slices from wild-type C57bl/6 mice and AβPP-/- C57bl/6 mice. METHODS Depolarization of acute cerebral slices from wild-type C57bl/6 and AβPP-/- C57bl/6 mice was used to induce synaptic signaling. Protein levels were examined by western blot and calcium dynamics were assessed using primary neuronal cultures. RESULTS In the absence of AβPP, decreased pCaMKII and pERKs levels were observed. This decrease was sensitive to the inhibition of N- and P/Q-type Voltage Gated Calcium Channels (N- and P/Q-VGCCs) by ω-conotoxin GVIA and ω-conotoxin MVIIC, respectively, but not to inhibition of L-type VGCCs by nifedipine. However, the absence of AβPP did not result in a statistically significant decrease of pCREB, which is a known substrate of pERKs. Finally, using calcium imaging, we found that down regulation of AβPP in cortical neurons results in a decreased response to depolarization and altered kinetics of calcium response. CONCLUSION AβPP regulates synaptic activity-mediated neuronal signaling by affecting N- and P/Q-VGCCs.
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Affiliation(s)
- Maria Chatzistavraki
- Department of Biology, Division of Animal and Human Physiology, National and Kapodistrian University of Athens, Panepistimiopolis, Ilisia, Greece
| | - Panagiota Papazafiri
- Department of Biology, Division of Animal and Human Physiology, National and Kapodistrian University of Athens, Panepistimiopolis, Ilisia, Greece
| | - Spiros Efthimiopoulos
- Department of Biology, Division of Animal and Human Physiology, National and Kapodistrian University of Athens, Panepistimiopolis, Ilisia, Greece
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17
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Tereshkina EB, Boksha IS, Prokhorova TA, Savushkina OK, Burbaeva GS, Morozova MA, Mukaetova-Ladinska EB. Decrease in 130 kDa- amyloid protein precursor protein (APP) and APP protein ratio in schizophrenia platelets. Neurosci Lett 2020; 725:134914. [PMID: 32194134 DOI: 10.1016/j.neulet.2020.134914] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 03/05/2020] [Accepted: 03/15/2020] [Indexed: 11/17/2022]
Abstract
Cognitive dysfunction is common among people with schizophrenia. The molecular substrates underlying this remain poorly understood. To address this, we analyzed changes in amyloid precursor protein (APP) in platelets of people with acute schizophrenia (n=24) and control subjects (n=20) by ECL-immunoblotting. APP bands corresponding to molecular masses of ∼130, ∼110 and ∼100 kDa, and the APP ratio (APPr: highest APP molecular mass vs lowest APP molecular mass bands) were quantified. The intensity of 130 kDa-APP and the APPr were significantly reduced in schizophrenia patients compared to control subjects. The age-associated decreases in the 130 kDa, ∼110 kDa proteins and APPr were present in patients, but not controls. Our results confirm peripheral APP metabolism is altered in people with schizophrenia. Further work is now warranted on a larger sample of diseased subjects with detailed cognitive assessment to determine the APP role in cognitive processing in schizophrenia, how it is related to severity and disease progression, as well as outcomes.
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Affiliation(s)
| | - I S Boksha
- Mental Health Research Centre, Moscow, Russia; N. F. Gamaleya National Research Center of Epidemiology and Microbiology, Ministry of Health of the Russian Federation, 123098 Moscow, Russia.
| | | | | | | | | | - E B Mukaetova-Ladinska
- Department of Neuroscience, Psychology and Behavior, University of Leicester, Leicester, LE1 7RH, UK; The Evington Centre, Leicestershire Partnership NHS Trust, Leicester General Hospital, Gwendolen Rd, Leicester LE5 4QG, UK
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18
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Ray B, Maloney B, Sambamurti K, Karnati HK, Nelson PT, Greig NH, Lahiri DK. Rivastigmine modifies the α-secretase pathway and potentially early Alzheimer's disease. Transl Psychiatry 2020; 10:47. [PMID: 32066688 PMCID: PMC7026402 DOI: 10.1038/s41398-020-0709-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 11/25/2019] [Accepted: 12/19/2019] [Indexed: 12/12/2022] Open
Abstract
Rivastigmine (or Exelon) is a cholinesterase inhibitor, currently used as a symptomatic treatment for mild-to-moderate Alzheimer's disease (AD). Amyloid-β peptide (Aβ) generated from its precursor protein (APP) by β-secretase (or BACE1) and γ-secretase endoproteolysis. Alternative APP cleavage by α-secretase (a family of membrane-bound metalloproteases- Adamalysins) precludes the generation of toxic Aβ and yields a neuroprotective and neurotrophic secreted sAPPα fragment. Several signal transduction pathways, including protein kinase C and MAP kinase, stimulate α-secretase. We present data to suggest that rivastigmine, in addition to anticholinesterase activity, directs APP processing away from BACE1 and towards α-secretases. We treated rat neuronal PC12 cells and primary human brain (PHB) cultures with rivastigmine and the α-secretase inhibitor TAPI and assayed for levels of APP processing products and α-secretases. We subsequently treated 3×Tg (transgenic) mice with rivastigmine and harvested hippocampi to assay for levels of APP processing products. We also assayed postmortem human control, AD, and AD brains from subjects treated with rivastigmine for levels of APP metabolites. Rivastigmine dose-dependently promoted α-secretase activity by upregulating levels of ADAM-9, -10, and -17 α-secretases in PHB cultures. Co-treatment with TAPI eliminated rivastigmine-induced sAPPα elevation. Rivastigmine treatment elevated levels of sAPPα in 3×Tg mice. Consistent with these results, we also found elevated sAPPα in postmortem brain samples from AD patients treated with rivastigmine. Rivastigmine can modify the levels of several shedding proteins and directs APP processing toward the non-amyloidogenic pathway. This novel property of rivastigmine can be therapeutically exploited for disease-modifying intervention that goes beyond symptomatic treatment for AD.
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Affiliation(s)
- Balmiki Ray
- grid.257413.60000 0001 2287 3919Department of Psychiatry, Laboratory of Molecular Neurogenetics, Indiana University School of Medicine, Indianapolis, IN 46202 USA
| | - Bryan Maloney
- grid.257413.60000 0001 2287 3919Department of Psychiatry, Laboratory of Molecular Neurogenetics, Indiana University School of Medicine, Indianapolis, IN 46202 USA ,grid.257413.60000 0001 2287 3919Indiana Alzheimer Disease Center, Indiana University School of Medicine, Indianapolis, IN 46202 USA
| | - Kumar Sambamurti
- grid.259828.c0000 0001 2189 3475Department of Neurosciences, Medical University of South Carolina, Charleston, 29425 SC USA
| | - Hanuma K. Karnati
- grid.419475.a0000 0000 9372 4913National Institute on Aging, Drug Design and Development Section, Bethesda, MD 20892 USA
| | - Peter T. Nelson
- grid.266539.d0000 0004 1936 8438Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40536 USA
| | - Nigel H. Greig
- grid.419475.a0000 0000 9372 4913National Institute on Aging, Drug Design and Development Section, Bethesda, MD 20892 USA
| | - Debomoy K. Lahiri
- grid.257413.60000 0001 2287 3919Department of Psychiatry, Laboratory of Molecular Neurogenetics, Indiana University School of Medicine, Indianapolis, IN 46202 USA ,grid.257413.60000 0001 2287 3919Indiana Alzheimer Disease Center, Indiana University School of Medicine, Indianapolis, IN 46202 USA ,grid.257413.60000 0001 2287 3919Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202 USA
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19
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Abstract
The Amyloid Precursor Protein (APP) is infamous for its proposed pivotal role in the pathogenesis of Alzheimer’s disease (AD). Much research on APP focusses on potential contributions to neurodegeneration, mostly based on mouse models with altered expression or mutated forms of APP. However, cumulative evidence from recent years indicates the indispensability of APP and its metabolites for normal brain physiology. APP contributes to the regulation of synaptic transmission, plasticity, and calcium homeostasis. It plays an important role during development and it exerts neuroprotective effects. Of particular importance is the soluble secreted fragment APPsα which mediates many of its physiological actions, often counteracting the effects of the small APP-derived peptide Aβ. Understanding the contribution of APP for normal functions of the nervous system is of high importance, both from a basic science perspective and also as a basis for generating new pathophysiological concepts and therapeutic approaches in AD. In this article, we review the physiological functions of APP and its metabolites, focusing on synaptic transmission, plasticity, calcium signaling, and neuronal network activity.
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Affiliation(s)
- Dimitri Hefter
- Institute of Physiology and Pathophysiology, Heidelberg University, Heidelberg, Germany.,RG Animal Models in Psychiatry, Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Susann Ludewig
- Helmholtz Centre for Infection Research, Neuroinflammation and Neurodegeneration Group, Braunschweig, Germany.,Cellular Neurobiology, Zoological Institute, Technical University Braunschweig, Braunschweig, Germany
| | - Andreas Draguhn
- Institute of Physiology and Pathophysiology, Heidelberg University, Heidelberg, Germany
| | - Martin Korte
- Helmholtz Centre for Infection Research, Neuroinflammation and Neurodegeneration Group, Braunschweig, Germany.,Cellular Neurobiology, Zoological Institute, Technical University Braunschweig, Braunschweig, Germany
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20
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New Alzheimer's disease model mouse specialized for analyzing the function and toxicity of intraneuronal Amyloid β oligomers. Sci Rep 2019; 9:17368. [PMID: 31757975 PMCID: PMC6874556 DOI: 10.1038/s41598-019-53415-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 10/29/2019] [Indexed: 11/11/2022] Open
Abstract
Oligomers of intracellular amyloid β protein (Aβ) are strongly cytotoxic and play crucial roles in synaptic transmission and cognitive function in Alzheimer’s disease (AD). However, there is currently no AD model mouse in which to specifically analyze the function of Aβ oligomers only. We have now developed a novel AD model mouse, an Aβ-GFP transgenic mouse (Aβ-GFP Tg), that expresses the GFP-fused human Aβ1-42 protein, which forms only Aβ oligomers within neurons throughout their life. The fusion proteins are expressed mainly in the hippocampal CA1-CA2 region and cerebral cortex, and are not secreted extracellularly. The Aβ-GFP Tg mice exhibit increased tau phosphorylation, altered spine morphology, decreased expressions of the GluN2B receptor and neuroligin in synaptic regions, attenuated hippocampal long-term potentiation, and impaired object recognition memory compared with non-Tg littermates. Interestingly, these dysfunctions have already appeared in 2–3-months-old animals. The Aβ-GFP fusion protein is bioactive and highly toxic, and induces the similar synaptic dysfunctions as the naturally generated Aβ oligomer derived from postmortem AD patient brains and synthetic Aβ oligomers. Thus, Aβ-GFP Tg mouse is a new tool specialized to analyze the function of Aβ oligomers in vivo and to find subtle changes in synapses in early symptoms of AD.
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21
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Tiwari S, Atluri V, Kaushik A, Yndart A, Nair M. Alzheimer's disease: pathogenesis, diagnostics, and therapeutics. Int J Nanomedicine 2019; 14:5541-5554. [PMID: 31410002 PMCID: PMC6650620 DOI: 10.2147/ijn.s200490] [Citation(s) in RCA: 549] [Impact Index Per Article: 109.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Accepted: 03/02/2019] [Indexed: 12/12/2022] Open
Abstract
Currently, 47 million people live with dementia globally, and it is estimated to increase more than threefold (~131 million) by 2050. Alzheimer's disease (AD) is one of the major causative factors to induce progressive dementia. AD is a neurodegenerative disease, and its pathogenesis has been attributed to extracellular aggregates of amyloid β (Aβ) plaques and intracellular neurofibrillary tangles made of hyperphosphorylated τ-protein in cortical and limbic areas of the human brain. It is characterized by memory loss and progressive neurocognitive dysfunction. The anomalous processing of APP by β-secretases and γ-secretases leads to production of Aβ40 and Aβ42 monomers, which further oligomerize and aggregate into senile plaques. The disease also intensifies through infectious agents like HIV. Additionally, during disease pathogenesis, the presence of high concentrations of Aβ peptides in central nervous system initiates microglial infiltration. Upon coming into vicinity of Aβ, microglia get activated, endocytose Aβ, and contribute toward their clearance via TREM2 surface receptors, simultaneously triggering innate immunoresponse against the aggregation. In addition to a detailed report on causative factors leading to AD, the present review also discusses the current state of the art in AD therapeutics and diagnostics, including labeling and imaging techniques employed as contrast agents for better visualization and sensing of the plaques. The review also points to an urgent need for nanotechnology as an efficient therapeutic strategy to increase the bioavailability of drugs in the central nervous system.
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Affiliation(s)
- Sneham Tiwari
- Department of Immunology and Nano-Medicine, Institute of NeuroImmune Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL33199, USA
| | - Venkata Atluri
- Department of Immunology and Nano-Medicine, Institute of NeuroImmune Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL33199, USA
| | - Ajeet Kaushik
- Department of Immunology and Nano-Medicine, Institute of NeuroImmune Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL33199, USA
| | - Adriana Yndart
- Department of Immunology and Nano-Medicine, Institute of NeuroImmune Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL33199, USA
| | - Madhavan Nair
- Department of Immunology and Nano-Medicine, Institute of NeuroImmune Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL33199, USA
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22
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Tan JZA, Gleeson PA. The trans-Golgi network is a major site for α-secretase processing of amyloid precursor protein in primary neurons. J Biol Chem 2019; 294:1618-1631. [PMID: 30545942 PMCID: PMC6364769 DOI: 10.1074/jbc.ra118.005222] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 12/12/2018] [Indexed: 01/09/2023] Open
Abstract
Amyloid precursor protein (APP) is processed along the amyloidogenic pathway by the β-secretase, BACE1, generating β-amyloid (Aβ), or along the nonamyloidogenic pathway by α-secretase, precluding Aβ production. The plasma membrane is considered the major site for α-secretase-mediated APP cleavage, but other cellular locations have not been rigorously investigated. Here, we report that APP is processed by endogenous α-secretase at the trans-Golgi network (TGN) of both transfected HeLa cells and mouse primary neurons. We have previously shown the adaptor protein complex, AP-4, and small G protein ADP-ribosylation factor-like GTPase 5b (Arl5b) are required for efficient post-Golgi transport of APP to endosomes. We found here that AP-4 or Arl5b depletion results in Golgi accumulation of APP and increased secretion of the soluble α-secretase cleavage product sAPPα. Moreover, inhibition of γ-secretase following APP accumulation in the TGN increases the levels of the membrane-bound C-terminal fragments of APP from both α-secretase cleavage (α-CTF, named C83 according to its band size) and BACE1 cleavage (β-CTF/C99). The level of C83 was ∼4 times higher than that of C99, indicating that α-secretase processing is the major pathway and that BACE1 processing is the minor pathway in the TGN. AP-4 silencing in mouse primary neurons also resulted in the accumulation of endogenous APP in the TGN and enhanced α-secretase processing. These findings identify the TGN as a major site for α-secretase processing in HeLa cells and primary neurons and indicate that both APP processing pathways can occur within the TGN compartment along the secretory pathway.
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Affiliation(s)
- Jing Zhi A Tan
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Paul A Gleeson
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, Victoria 3010, Australia.
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23
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Lopez Sanchez MIG, van Wijngaarden P, Trounce IA. Amyloid precursor protein-mediated mitochondrial regulation and Alzheimer's disease. Br J Pharmacol 2018; 176:3464-3474. [PMID: 30471088 DOI: 10.1111/bph.14554] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Revised: 10/29/2018] [Accepted: 11/10/2018] [Indexed: 12/16/2022] Open
Abstract
Despite clear evidence of a neuroprotective physiological role of amyloid precursor protein (APP) and its non-amyloidogenic processing products, APP has been investigated mainly in animal and cellular models of amyloid pathology in the context of Alzheimer's disease. The rare familial mutations in APP and presenilin-1/2, which sometimes drive increased amyloid β (Aβ) production, may have unduly influenced Alzheimer's disease research. APP and its cleavage products play important roles in cellular and mitochondrial metabolism, but many studies focus solely on Aβ. Mitochondrial bioenergetic metabolism is essential for neuronal function, maintenance and survival, and multiple reports indicate mitochondrial abnormalities in patients with Alzheimer's disease. In this review, we focus on mitochondrial abnormalities reported in sporadic Alzheimer's disease patients and the role of full-length APP and its non-amyloidogenic fragments, particularly soluble APPα, on mitochondrial bioenergetic metabolism. We do not review the plethora of animal and in vitro studies using mutant APP/presenilin constructs or experiments using exogenous Aβ. In doing so, we aim to invigorate research and discussion around non-amyloidogenic APP processing products and the mechanisms linking mitochondria and complex neurodegenerative disorders such as sporadic Alzheimer's disease. LINKED ARTICLES: This article is part of a themed section on Therapeutics for Dementia and Alzheimer's Disease: New Directions for Precision Medicine. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.18/issuetoc.
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Affiliation(s)
- M Isabel G Lopez Sanchez
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, VIC, Australia.,Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia
| | - Peter van Wijngaarden
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, VIC, Australia.,Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia
| | - Ian A Trounce
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, VIC, Australia.,Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia
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24
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Truong PH, Ciccotosto GD, Cappai R. Analysis of Motor Function in Amyloid Precursor-Like Protein 2 Knockout Mice: The Effects of Ageing and Sex. Neurochem Res 2018; 44:1356-1366. [PMID: 30362021 DOI: 10.1007/s11064-018-2669-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 10/18/2018] [Accepted: 10/20/2018] [Indexed: 12/19/2022]
Abstract
The amyloid precursor protein (APP) is a member of a conserved gene family that includes the amyloid precursor-like proteins 1 (APLP1) and 2 (APLP2). APP and APLP2 share a high degree of similarity, and have overlapping patterns of spatial and temporal expression in the central and peripheral tissues, in particular at the neuromuscular junction. APP-family knockout (KO) studies have helped elucidate aspects of function and functional redundancy amongst the APP-family members. In the present study, we investigated motor performance of APLP2-KO mice and the effect sex differences and age-related changes have on motor performance. APLP2-KO and WT (on C57Bl6 background) littermates control mice from 8 (young adulthood) to 48 weeks (middle age) were investigated. Analysis of motor neuron and muscle morphology showed APLP2-KO females but not males, had less age-related motor function impairments. We observed age and sex differences in both motor neuron number and muscle fiber size distribution for APLP2-KO mice compared to WT (C57Bl6). These alterations in the motor neuron number and muscle fiber distribution pattern may explain why female APLP2-KO mice have far better motor function behaviour during ageing.
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Affiliation(s)
- Phan H Truong
- Department of Pharmacology and Therapeutics, The University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Giuseppe D Ciccotosto
- Department of Pharmacology and Therapeutics, The University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Roberto Cappai
- Department of Pharmacology and Therapeutics, The University of Melbourne, Melbourne, VIC, 3010, Australia.
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25
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Richter MC, Ludewig S, Winschel A, Abel T, Bold C, Salzburger LR, Klein S, Han K, Weyer SW, Fritz AK, Laube B, Wolfer DP, Buchholz CJ, Korte M, Müller UC. Distinct in vivo roles of secreted APP ectodomain variants APPsα and APPsβ in regulation of spine density, synaptic plasticity, and cognition. EMBO J 2018; 37:embj.201798335. [PMID: 29661886 DOI: 10.15252/embj.201798335] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 02/23/2018] [Accepted: 03/02/2018] [Indexed: 11/09/2022] Open
Abstract
Increasing evidence suggests that synaptic functions of the amyloid precursor protein (APP), which is key to Alzheimer pathogenesis, may be carried out by its secreted ectodomain (APPs). The specific roles of APPsα and APPsβ fragments, generated by non-amyloidogenic or amyloidogenic APP processing, respectively, remain however unclear. Here, we expressed APPsα or APPsβ in the adult brain of conditional double knockout mice (cDKO) lacking APP and the related APLP2. APPsα efficiently rescued deficits in spine density, synaptic plasticity (LTP and PPF), and spatial reference memory of cDKO mice. In contrast, APPsβ failed to show any detectable effects on synaptic plasticity and spine density. The C-terminal 16 amino acids of APPsα (lacking in APPsβ) proved sufficient to facilitate LTP in a mechanism that depends on functional nicotinic α7-nAChRs. Further, APPsα showed high-affinity, allosteric potentiation of heterologously expressed α7-nAChRs in oocytes. Collectively, we identified α7-nAChRs as a crucial physiological receptor specific for APPsα and show distinct in vivo roles for APPsα versus APPsβ. This implies that reduced levels of APPsα that might occur during Alzheimer pathogenesis cannot be compensated by APPsβ.
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Affiliation(s)
- Max C Richter
- Institute of Pharmacy and Molecular Biotechnology (IPMB), Ruprecht-Karls University Heidelberg, Heidelberg, Germany
| | - Susann Ludewig
- Zoological Institute, Division of Cellular Neurobiology, TU Braunschweig, Braunschweig, Germany
| | - Alex Winschel
- Department of Biology, Neurophysiology und Neurosensory Systems, TU Darmstadt, Darmstadt, Germany
| | - Tobias Abel
- Paul-Ehrlich-Institut (PEI), Langen, Germany
| | - Charlotte Bold
- Institute of Pharmacy and Molecular Biotechnology (IPMB), Ruprecht-Karls University Heidelberg, Heidelberg, Germany
| | - Leonie R Salzburger
- Zoological Institute, Division of Cellular Neurobiology, TU Braunschweig, Braunschweig, Germany
| | - Susanne Klein
- Institute of Pharmacy and Molecular Biotechnology (IPMB), Ruprecht-Karls University Heidelberg, Heidelberg, Germany
| | - Kang Han
- Institute of Pharmacy and Molecular Biotechnology (IPMB), Ruprecht-Karls University Heidelberg, Heidelberg, Germany
| | - Sascha W Weyer
- Institute of Pharmacy and Molecular Biotechnology (IPMB), Ruprecht-Karls University Heidelberg, Heidelberg, Germany
| | - Ann-Kristina Fritz
- Institute of Anatomy, University of Zurich, Zurich, Switzerland.,Institute of Human Movements Sciences and Sport, ETH Zurich, Zurich, Switzerland
| | - Bodo Laube
- Department of Biology, Neurophysiology und Neurosensory Systems, TU Darmstadt, Darmstadt, Germany
| | - David P Wolfer
- Institute of Anatomy, University of Zurich, Zurich, Switzerland.,Institute of Human Movements Sciences and Sport, ETH Zurich, Zurich, Switzerland
| | | | - Martin Korte
- Zoological Institute, Division of Cellular Neurobiology, TU Braunschweig, Braunschweig, Germany.,Helmholtz Centre for Infection Research, AG NIND, Braunschweig, Germany
| | - Ulrike C Müller
- Institute of Pharmacy and Molecular Biotechnology (IPMB), Ruprecht-Karls University Heidelberg, Heidelberg, Germany
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26
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Hefter D, Marti HH, Gass P, Inta D. Perinatal Hypoxia and Ischemia in Animal Models of Schizophrenia. Front Psychiatry 2018; 9:106. [PMID: 29651259 PMCID: PMC5884869 DOI: 10.3389/fpsyt.2018.00106] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 03/16/2018] [Indexed: 12/12/2022] Open
Abstract
Intrauterine or perinatal complications constitute a major risk for psychiatric diseases. Infants who suffered from hypoxia-ischemia (HI) are at twofold risk to develop schizophrenia in later life. Several animal models attempt to reproduce these complications to study the yet unknown steps between an insult in early life and outbreak of the disease decades later. However, it is very challenging to find the right type and severity of insult leading to a disease-like phenotype in the animal, but not causing necrosis and focal neurological deficits. By contrast, too mild, repetitive insults may even be protective via conditioning effects. Thus, it is not surprising that animal models of hypoxia lead to mixed results. To achieve clinically translatable findings, better protocols are urgently needed. Therefore, we compare widely used models of hypoxia and HI and propose future directions for the field.
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Affiliation(s)
- Dimitri Hefter
- RG Animal Models in Psychiatry, Department of Psychiatry and Psychotherapy, Medical Faculty Mannheim, Central Institute of Mental Health, University of Heidelberg, Heidelberg, Germany.,RG Neuro- and Sensory Physiology, Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Hugo H Marti
- RG Neurovascular Research, Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Peter Gass
- RG Animal Models in Psychiatry, Department of Psychiatry and Psychotherapy, Medical Faculty Mannheim, Central Institute of Mental Health, University of Heidelberg, Heidelberg, Germany
| | - Dragos Inta
- RG Animal Models in Psychiatry, Department of Psychiatry and Psychotherapy, Medical Faculty Mannheim, Central Institute of Mental Health, University of Heidelberg, Heidelberg, Germany.,Department of Psychiatry, University of Basel, Basel, Switzerland
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27
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Polanco JC, Li C, Bodea LG, Martinez-Marmol R, Meunier FA, Götz J. Amyloid-β and tau complexity — towards improved biomarkers and targeted therapies. Nat Rev Neurol 2017; 14:22-39. [DOI: 10.1038/nrneurol.2017.162] [Citation(s) in RCA: 235] [Impact Index Per Article: 33.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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28
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Wang HY, Lee KC, Pei Z, Khan A, Bakshi K, Burns LH. PTI-125 binds and reverses an altered conformation of filamin A to reduce Alzheimer's disease pathogenesis. Neurobiol Aging 2017; 55:99-114. [DOI: 10.1016/j.neurobiolaging.2017.03.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 03/06/2017] [Accepted: 03/09/2017] [Indexed: 11/30/2022]
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29
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Han K, Müller UC, Hülsmann S. Amyloid-precursor Like Proteins APLP1 and APLP2 Are Dispensable for Normal Development of the Neonatal Respiratory Network. Front Mol Neurosci 2017; 10:189. [PMID: 28690498 PMCID: PMC5479907 DOI: 10.3389/fnmol.2017.00189] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 05/29/2017] [Indexed: 11/13/2022] Open
Abstract
Recent studies using animal models indicated that the members of the amyloid precursor protein (APP) gene family are important for the formation, maintenance, and plasticity of synapses. Despite this, the specific role of the APP homologs APLP1 and APLP2 within the CNS and PNS is still poorly understood. In contrast to the subtle phenotypes of single mutants, double knockout mice (DKO) lacking APP/APLP2 or APLP1/APLP2 die within the first day after birth. Whereas APP/APLP2-DKO mice show severe deficits of neuromuscular morphology and transmission, the underlying cause of lethality of APLP1/APLP2-DKO mice remains unclear. Since expression of both proteins was confirmed by in situ hybridization, we aimed to test the role of APLP1/APLP2 in the formation and maintenance of synapses in the brainstem, and assessed a potential dysfunction of the most vital central neuronal network in APLP1/APLP2-DKO mice by analyzing the respiratory network of the medulla. We performed in vivo unrestrained whole body plethysmography in newborn APLP1/APLP2-DKO mice at postnatal day zero. Additionally, we directly tested the activity of the respiratory network in an acute slice preparation that includes the pre-Bötzinger complex. In both sets of experiments, no significant differences were detected regarding respiratory rate and cycle variability, strongly arguing against central respiratory problems as the primary cause of death of APLP1/APLP2-DKO mice. Thus, we conclude that APLP1 and APLP2 are dispensable for the development of the network and the generation of a normal breathing rhythm.
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Affiliation(s)
- Kang Han
- Institute of Pharmacy and Molecular Biotechnology, Heidelberg UniversityHeidelberg, Germany
| | - Ulrike C Müller
- Institute of Pharmacy and Molecular Biotechnology, Heidelberg UniversityHeidelberg, Germany
| | - Swen Hülsmann
- Klinik für Anästhesiologie, Universitätsmedizin GöttingenGöttingen, Germany.,Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB)Göttingen, Germany
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30
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Not just amyloid: physiological functions of the amyloid precursor protein family. Nat Rev Neurosci 2017; 18:281-298. [PMID: 28360418 DOI: 10.1038/nrn.2017.29] [Citation(s) in RCA: 371] [Impact Index Per Article: 53.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Amyloid precursor protein (APP) gives rise to the amyloid-β peptide and thus has a key role in the pathogenesis of Alzheimer disease. By contrast, the physiological functions of APP and the closely related APP-like proteins (APLPs) remain less well understood. Studying these physiological functions has been challenging and has required a careful long-term strategy, including the analysis of different App-knockout and Aplp-knockout mice. In this Review, we summarize these findings, focusing on the in vivo roles of APP family members and their processing products for CNS development, synapse formation and function, brain injury and neuroprotection, as well as ageing. In addition, we discuss the implications of APP physiology for therapeutic approaches.
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Mockett BG, Richter M, Abraham WC, Müller UC. Therapeutic Potential of Secreted Amyloid Precursor Protein APPsα. Front Mol Neurosci 2017; 10:30. [PMID: 28223920 PMCID: PMC5293819 DOI: 10.3389/fnmol.2017.00030] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 01/25/2017] [Indexed: 11/26/2022] Open
Abstract
Cleavage of the amyloid precursor protein (APP) by α-secretase generates an extracellularly released fragment termed secreted APP-alpha (APPsα). Not only is this process of interest due to the cleavage of APP within the amyloid-beta sequence, but APPsα itself has many physiological properties that suggest its great potential as a therapeutic target. For example, APPsα is neurotrophic, neuroprotective, neurogenic, a stimulator of protein synthesis and gene expression, and enhances long-term potentiation (LTP) and memory. While most early studies have been conducted in vitro, effectiveness in animal models is now being confirmed. These studies have revealed that either upregulating α-secretase activity, acutely administering APPsα or chronic delivery of APPsα via a gene therapy approach can effectively treat mouse models of Alzheimer's disease (AD) and other disorders such as traumatic head injury. Together these findings suggest the need for intensifying research efforts to harness the therapeutic potential of this multifunctional protein.
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Affiliation(s)
- Bruce G. Mockett
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of OtagoOtago, New Zealand
| | - Max Richter
- Department of Functional Genomics, Institute for Pharmacy and Molecular Biotechnology, Heidelberg UniversityHeidelberg, Germany
| | - Wickliffe C. Abraham
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of OtagoOtago, New Zealand
| | - Ulrike C. Müller
- Department of Functional Genomics, Institute for Pharmacy and Molecular Biotechnology, Heidelberg UniversityHeidelberg, Germany
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Hefter D, Draguhn A. APP as a Protective Factor in Acute Neuronal Insults. Front Mol Neurosci 2017; 10:22. [PMID: 28210211 PMCID: PMC5288400 DOI: 10.3389/fnmol.2017.00022] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 01/16/2017] [Indexed: 12/25/2022] Open
Abstract
Despite its key role in the molecular pathology of Alzheimer’s disease (AD), the physiological function of amyloid precursor protein (APP) is unknown. Increasing evidence, however, points towards a neuroprotective role of this membrane protein in situations of metabolic stress. A key observation is the up-regulation of APP following acute (stroke, cardiac arrest) or chronic (cerebrovascular disease) hypoxic-ischemic conditions. While this mechanism may increase the risk or severity of AD, APP by itself or its soluble extracellular fragment APPsα can promote neuronal survival. Indeed, different animal models of acute hypoxia-ischemia, traumatic brain injury (TBI) and excitotoxicity have revealed protective effects of APP or APPsα. The underlying mechanisms involve APP-mediated regulation of calcium homeostasis via NMDA receptors (NMDAR), voltage-gated calcium channels (VGCC) or internal calcium stores. In addition, APP affects the expression of survival- or apoptosis-related genes as well as neurotrophic factors. In this review, we summarize the current understanding of the neuroprotective role of APP and APPsα and possible implications for future research and new therapeutic strategies.
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Affiliation(s)
- Dimitri Hefter
- Institute of Physiology and Pathophysiology, Heidelberg UniversityHeidelberg, Germany; Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg UniversityMannheim, Germany
| | - Andreas Draguhn
- Institute of Physiology and Pathophysiology, Heidelberg University Heidelberg, Germany
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Ludewig S, Korte M. Novel Insights into the Physiological Function of the APP (Gene) Family and Its Proteolytic Fragments in Synaptic Plasticity. Front Mol Neurosci 2017; 9:161. [PMID: 28163673 PMCID: PMC5247455 DOI: 10.3389/fnmol.2016.00161] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 12/14/2016] [Indexed: 12/31/2022] Open
Abstract
The amyloid precursor protein (APP) is well known to be involved in the pathophysiology of Alzheimer's disease (AD) via its cleavage product amyloid ß (Aß). However, the physiological role of APP, its various proteolytic products and the amyloid precursor-like proteins 1 and 2 (APLP1/2) are still not fully clarified. Interestingly, it has been shown that learning and memory processes represented by functional and structural changes at synapses are altered in different APP and APLP1/2 mouse mutants. In addition, APP and its fragments are implicated in regulating synaptic strength further reinforcing their modulatory role at the synapse. While APLP2 and APP are functionally redundant, the exclusively CNS expressed APLP1, might have individual roles within the synaptic network. The proteolytic product of non-amyloidogenic APP processing, APPsα, emerged as a neurotrophic peptide that facilitates long-term potentiation (LTP) and restores impairments occurring with age. Interestingly, the newly discovered η-secretase cleavage product, An-α acts in the opposite direction, namely decreasing LTP. In this review we summarize recent findings with emphasis on the physiological role of the APP gene family and its proteolytic products on synaptic function and plasticity, especially during processes of hippocampal LTP. Therefore, we focus on literature that provide electrophysiological data by using different mutant mouse strains either lacking full-length or parts of the APP proteins or that utilized secretase inhibitors as well as secreted APP fragments.
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Affiliation(s)
- Susann Ludewig
- Division of Cellular Neurobiology, Zoological Institute, TU Braunschweig Braunschweig, Germany
| | - Martin Korte
- Division of Cellular Neurobiology, Zoological Institute, TU BraunschweigBraunschweig, Germany; Helmholtz Centre for Infection Research, AG NINDBraunschweig, Germany
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Burns LH, Wang HY. Altered filamin A enables amyloid beta-induced tau hyperphosphorylation and neuroinflammation in Alzheimer's disease. NEUROIMMUNOLOGY AND NEUROINFLAMMATION 2017; 4:263-271. [PMID: 34295950 PMCID: PMC8294116 DOI: 10.20517/2347-8659.2017.50] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Alzheimer’s disease (AD) is a neurodegenerative disease with proteopathy characterized by abnormalities in amyloid beta (Aβ) and tau proteins. Defective amyloid and tau propagate and aggregate, leading to eventual amyloid plaques and neurofibrillary tangles. New data show that a third proteopathy, an altered conformation of the scaffolding protein filamin A (FLNA), is critically linked to the amyloid and tau pathologies in AD. Altered FLNA is pervasive in AD brain and without apparent aggregation. In a striking interdependence, altered FLNA is both induced by Aβ and required for two prominent pathogenic signaling pathways of Aβ. Aβ monomers or small oligomers signal via the α7 nicotinic acetylcholine receptor (α7nAChR) to activate kinases that hyperphosphorylate tau to cause neurofibrillary lesions and formation of neurofibrillary tangles. Altered FLNA also enables a persistent activation of toll-like-receptor 4 (TLR4) by Aβ, leading to excessive inflammatory cytokine release and neuroinflammation. The novel AD therapeutic candidate PTI-125 binds and reverses the altered FLNA conformation to prevent Aβ’s signaling via α7nAChR and aberrant activation of TLR4, thus reducing multiple AD-related neuropathologies. As a regulator of Aβ’s signaling via α7nAChR and TLR4, altered FLNA represents a novel AD therapeutic target.
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Affiliation(s)
| | - Hoau-Yan Wang
- Department of Physiology, Pharmacology and Neuroscience, City University of New York School of Medicine, New York, NY 10031, USA.,Department of Biology and Neuroscience, Graduate School of the City University of New York, New York, NY 10031, USA
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