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Coronel R, López-Alonso V, Gallego MI, Liste I. Low Levels of Amyloid Precursor Protein (APP) Promote Neurogenesis and Decrease Gliogenesis in Human Neural Stem Cells. Int J Mol Sci 2023; 24:14635. [PMID: 37834082 PMCID: PMC10572469 DOI: 10.3390/ijms241914635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 09/22/2023] [Accepted: 09/25/2023] [Indexed: 10/15/2023] Open
Abstract
Amyloid precursor protein (APP) has been widely studied due to its association with Alzheimer's disease (AD). However, the physiological functions of APP are still largely unexplored. APP is a transmembrane glycoprotein whose expression in humans is abundant in the central nervous system. Specifically, several studies have revealed the high expression of APP during brain development. Previous studies in our laboratory revealed that a transient increase in APP expression induces early cell cycle exit of human neural stem cells (hNSCs) and directs their differentiation towards glial cells (gliogenesis) while decreasing their differentiation towards neurons (neurogenesis). In the present study, we have evaluated the intrinsic cellular effects of APP down-expression (using siRNA) on cell death, cell proliferation, and cell fate specification of hNSCs. Our data indicate that APP silencing causes cellular effects opposite to those obtained in previous APP overexpression assays, inducing cell proliferation in hNS1 cells (a model line of hNSCs) and favoring neurogenesis instead of gliogenesis in these cells. In addition, we have analyzed the gene and protein expression levels of β-Catenin as a possible molecule involved in these cellular effects. These data could help to understand the biological role of APP, which is necessary to deepen the knowledge of AD.
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Affiliation(s)
- Raquel Coronel
- Unidad de Regeneración Neural, Unidad Funcional de Investigación de Enfermedades Crónicas, Instituto de Salud Carlos III, 28220 Majadahonda, Madrid, Spain
- Departamento de Biología de Sistemas, Facultad de Medicina y Ciencias de la Salud, Universidad de Alcalá, 28871 Alcalá de Henares, Madrid, Spain
| | - Victoria López-Alonso
- Unidad de Biología Computacional, Unidad Funcional de Investigación de Enfermedades Crónicas, Instituto de Salud Carlos III, 28220 Majadahonda, Madrid, Spain;
| | - Marta I. Gallego
- Unidad de Histología y Patología Mamaria, Instituto de Salud Carlos III, 28220 Majadahonda, Madrid, Spain;
| | - Isabel Liste
- Unidad de Regeneración Neural, Unidad Funcional de Investigación de Enfermedades Crónicas, Instituto de Salud Carlos III, 28220 Majadahonda, Madrid, Spain
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2
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Smit T, Deshayes NAC, Borchelt DR, Kamphuis W, Middeldorp J, Hol EM. Reactive astrocytes as treatment targets in Alzheimer's disease-Systematic review of studies using the APPswePS1dE9 mouse model. Glia 2021; 69:1852-1881. [PMID: 33634529 PMCID: PMC8247905 DOI: 10.1002/glia.23981] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 02/04/2021] [Accepted: 02/08/2021] [Indexed: 12/15/2022]
Abstract
Astrocytes regulate synaptic communication and are essential for proper brain functioning. In Alzheimer's disease (AD) astrocytes become reactive, which is characterized by an increased expression of intermediate filament proteins and cellular hypertrophy. Reactive astrocytes are found in close association with amyloid-beta (Aβ) deposits. Synaptic communication and neuronal network function could be directly modulated by reactive astrocytes, potentially contributing to cognitive decline in AD. In this review, we focus on reactive astrocytes as treatment targets in AD in the APPswePS1dE9 AD mouse model, a widely used model to study amyloidosis and gliosis. We first give an overview of the model; that is, how it was generated, which cells express the transgenes, and the effect of its genetic background on Aβ pathology. Subsequently, to determine whether modifying reactive astrocytes in AD could influence pathogenesis and cognition, we review studies using this mouse model in which interventions were directly targeted at reactive astrocytes or had an indirect effect on reactive astrocytes. Overall, studies specifically targeting astrocytes to reduce astrogliosis showed beneficial effects on cognition, which indicates that targeting astrocytes should be included in developing novel therapies for AD.
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Affiliation(s)
- Tamar Smit
- Department of Translational NeuroscienceUniversity Medical Center Utrecht Brain Center, Utrecht UniversityUtrechtThe Netherlands
- Swammerdam Institute for Life SciencesCenter for Neuroscience, University of AmsterdamAmsterdamThe Netherlands
| | - Natasja A. C. Deshayes
- Department of Translational NeuroscienceUniversity Medical Center Utrecht Brain Center, Utrecht UniversityUtrechtThe Netherlands
- Swammerdam Institute for Life SciencesCenter for Neuroscience, University of AmsterdamAmsterdamThe Netherlands
| | - David R. Borchelt
- Center for Translational Research in Neurodegenerative Disease, McKnight Brain Institute, Department of NeuroscienceUniversity of Florida College of MedicineGainesvilleFloridaUSA
| | - Willem Kamphuis
- Netherlands Institute for NeuroscienceAn Institute of the Royal Netherlands Academy of Arts and SciencesAmsterdamThe Netherlands
| | - Jinte Middeldorp
- Department of Translational NeuroscienceUniversity Medical Center Utrecht Brain Center, Utrecht UniversityUtrechtThe Netherlands
- Department of ImmunobiologyBiomedical Primate Research CentreRijswijkThe Netherlands
| | - Elly M. Hol
- Department of Translational NeuroscienceUniversity Medical Center Utrecht Brain Center, Utrecht UniversityUtrechtThe Netherlands
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Wan Nasri WN, Makpol S, Mazlan M, Tooyama I, Wan Ngah WZ, Damanhuri HA. Tocotrienol Rich Fraction Supplementation Modulate Brain Hippocampal Gene Expression in APPswe/PS1dE9 Alzheimer's Disease Mouse Model. J Alzheimers Dis 2020; 70:S239-S254. [PMID: 30507571 PMCID: PMC6700627 DOI: 10.3233/jad-180496] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Alzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized by loss of memory and other cognitive abilities. AD is associated with aggregation of amyloid-β (Aβ) deposited in the hippocampal brain region. Our previous work has shown that tocotrienol rich fraction (TRF) supplementation was able to attenuate the blood oxidative status, improve behavior, and reduce fibrillary-type Aβ deposition in the hippocampus of an AD mouse model. In the present study, we investigate the effect of 6 months of TRF supplementation on transcriptome profile in the hippocampus of APPswe/PS1dE9 double transgenic mice. TRF supplementation can alleviate AD conditions by modulating several important genes in AD. Moreover, TRF supplementation attenuated the affected biological process and pathways that were upregulated in the AD mouse model. Our findings indicate that TRF supplementation can modulate hippocampal gene expression as well as biological processes that can potentially delay the progression of AD.
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Affiliation(s)
- Wan Nurzulaikha Wan Nasri
- Department of Biochemistry, Faculty of Medicine, Universiti Kebangsaan Malaysia, Cheras, Kuala Lumpur, Malaysia
| | - Suzana Makpol
- Department of Biochemistry, Faculty of Medicine, Universiti Kebangsaan Malaysia, Cheras, Kuala Lumpur, Malaysia
| | - Musalmah Mazlan
- Faculty of Medicine, Universiti Teknologi MARA, Sungai Buloh, Selangor, Malaysia
| | - Ikuo Tooyama
- Molecular Neuroscience Research Centre, Shiga University of Medical Sciences, Seta Tsukinowacho, Otsu, Shiga, Japan
| | - Wan Zurinah Wan Ngah
- Department of Biochemistry, Faculty of Medicine, Universiti Kebangsaan Malaysia, Cheras, Kuala Lumpur, Malaysia
| | - Hanafi Ahmad Damanhuri
- Department of Biochemistry, Faculty of Medicine, Universiti Kebangsaan Malaysia, Cheras, Kuala Lumpur, Malaysia
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Dai MH, Zheng H, Zeng LD, Zhang Y. The genes associated with early-onset Alzheimer's disease. Oncotarget 2018; 9:15132-15143. [PMID: 29599933 PMCID: PMC5871104 DOI: 10.18632/oncotarget.23738] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 10/14/2017] [Indexed: 01/31/2023] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder that accounts for the most cases of dementia, which is characterized by the deposition of dense plaques of amyloid beta (Aβ) plaques and neurofibrillary tangles consisting of hyperphosphorylated tau. The two main types of AD can be classified as early-onset AD (EOAD, onset < 65 years) and late-onset AD (LOAD, onset ≥ 65 years). Evidence from family and twin studies indicate that genetic factors are estimated to play a role in at least 80% of AD cases. The first milestone with linkage analysis revealed the mutations in APP, PSEN1, and PSEN2 genes that cause EOAD. But pathogenic mutations in these three genes can only explain a small fraction of EOAD families. The additional disease-causing genes have not yet been identified. This review provides an overview of the genetic basis of EOAD and the relationship between the functions of these risk genes and the neuropathologic features of AD. A better understanding of genetic mechanisms underlying EOAD pathogenesis and the potentially molecular mechanisms of neurodegeneration will lead to the development of effective diagnosis and treatment strategies for this devastating disease.
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Affiliation(s)
- Meng-Hui Dai
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Hui Zheng
- Department of Radiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Ling-Dan Zeng
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Yan Zhang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
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Stagni F, Giacomini A, Emili M, Guidi S, Bartesaghi R. Neurogenesis impairment: An early developmental defect in Down syndrome. Free Radic Biol Med 2018; 114:15-32. [PMID: 28756311 DOI: 10.1016/j.freeradbiomed.2017.07.026] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 07/24/2017] [Accepted: 07/25/2017] [Indexed: 02/06/2023]
Abstract
Down syndrome (DS) is characterized by brain hypotrophy and intellectual disability starting from early life stages. Accumulating evidence shows that the phenotypic features of the DS brain can be traced back to the fetal period since the DS brain exhibits proliferation potency reduction starting from the critical time window of fetal neurogenesis. This defect is worsened by the fact that neural progenitor cells exhibit reduced acquisition of a neuronal phenotype and an increase in the acquisition of an astrocytic phenotype. Consequently, the DS brain has fewer neurons in comparison with the typical brain. Although apoptotic cell death may be increased in DS, this does not seem to be the major cause of brain hypocellularity. Evidence obtained in brains of individuals with DS, DS-derived induced pluripotent stem cells (iPSCs), and DS mouse models has provided some insight into the mechanisms underlying the developmental defects due to the trisomic condition. Although many triplicated genes may be involved, in the light of the studies reviewed here, DYRK1A, APP, RCAN1 and OLIG1/2 appear to be particularly important determinants of many neurodevelopmental alterations that characterize DS because their triplication affects both the proliferation and fate of neural precursor cells as well as apoptotic cell death. Based on the evidence reviewed here, pathways downstream to these genes may represent strategic targets, for the design of possible interventions.
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Affiliation(s)
- Fiorenza Stagni
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Andrea Giacomini
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Marco Emili
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Sandra Guidi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Renata Bartesaghi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.
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Oliveira J, Costa M, de Almeida MSC, da Cruz e Silva OA, Henriques AG. Protein Phosphorylation is a Key Mechanism in Alzheimer’s Disease. J Alzheimers Dis 2017; 58:953-978. [DOI: 10.3233/jad-170176] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Joana Oliveira
- Department of Medical Sciences, Neuroscience and Signalling Laboratory, iBiMED, University of Aveiro, Aveiro, Portugal
| | - Márcio Costa
- Department of Medical Sciences, Neuroscience and Signalling Laboratory, iBiMED, University of Aveiro, Aveiro, Portugal
| | | | - Odete A.B. da Cruz e Silva
- Department of Medical Sciences, Neuroscience and Signalling Laboratory, iBiMED, University of Aveiro, Aveiro, Portugal
| | - Ana Gabriela Henriques
- Department of Medical Sciences, Neuroscience and Signalling Laboratory, iBiMED, University of Aveiro, Aveiro, Portugal
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Okuda A, Kurokawa S, Takehashi M, Maeda A, Fukuda K, Kubo Y, Nogusa H, Takatani-Nakase T, Okuda S, Ueda K, Tanaka S. Poly(ADP-ribose) polymerase inhibitors activate the p53 signaling pathway in neural stem/progenitor cells. BMC Neurosci 2017; 18:14. [PMID: 28095779 PMCID: PMC5240207 DOI: 10.1186/s12868-016-0333-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 12/28/2016] [Indexed: 11/24/2022] Open
Abstract
Background Poly(ADP-ribose) polymerase 1 (PARP-1), which catalyzes poly(ADP-ribosyl)ation of proteins by using NAD+ as a substrate, plays a key role in several nuclear events, including DNA repair, replication, and transcription. Recently, PARP-1 was reported to participate in the somatic cell reprogramming process. Previously, we revealed a role for PARP-1 in the induction of neural apoptosis in a cellular model of cerebral ischemia and suggested the possible use of PARP inhibitors as a new therapeutic intervention. In the present study, we examined the effects of PARP inhibitors on neural stem/progenitor cells (NSPCs) of the mouse brain.
Results PARP-1 was more abundant and demonstrated higher activity in NSPCs than in mouse embryonic fibroblasts. Treatment with PARP inhibitors suppressed the formation of neurospheres by NSPCs through the suppression of cell cycle progression and the induction of apoptosis. In order to identify the genes responsible for these effects, we investigated gene expression profiles by microarray analyses and found that several genes in the p53 signaling pathway were upregulated, including Cdkn1a, which is critical for cell cycle control, and Fas, Pidd, Pmaip1, and Bbc3, which are principal factors in the apoptosis pathway. Inhibition of poly(ADP-ribosyl)ation increased the levels of p53 protein, but not p53 mRNA, and enhanced the phosphorylation of p53 at Ser18. Experiments with specific inhibitors and also shRNA demonstrated that PARP-1, but not PARP-2, has a role in the regulation of p53. The effects of PARP inhibitors on NSPCs were not observed in Trp53−/− NSPCs, suggesting a key role for p53 in these events. Conclusions On the basis of the finding that PARP inhibitors facilitated the p53 signaling pathway, we propose that poly(ADP-ribosyl)ation contributes to the proliferation and self-renewal of NSPCs through the suppression of p53 activation.
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Affiliation(s)
- Akiko Okuda
- Laboratory of Pathophysiology and Pharmacotherapeutics, Faculty of Pharmacy, Osaka Ohtani University, 3-11-1 Nishikiori-kita, Tondabayashi, Osaka, 584-8540, Japan.,Niigata University Graduate School of Health Sciences, 2-746 Asahimachidori, Chuo-ku, Niigata, 951-8518, Japan
| | - Suguru Kurokawa
- Laboratory of Pathophysiology and Pharmacotherapeutics, Faculty of Pharmacy, Osaka Ohtani University, 3-11-1 Nishikiori-kita, Tondabayashi, Osaka, 584-8540, Japan
| | - Masanori Takehashi
- Laboratory of Pathophysiology and Pharmacotherapeutics, Faculty of Pharmacy, Osaka Ohtani University, 3-11-1 Nishikiori-kita, Tondabayashi, Osaka, 584-8540, Japan
| | - Aika Maeda
- Laboratory of Pathophysiology and Pharmacotherapeutics, Faculty of Pharmacy, Osaka Ohtani University, 3-11-1 Nishikiori-kita, Tondabayashi, Osaka, 584-8540, Japan
| | - Katsuya Fukuda
- Laboratory of Pathophysiology and Pharmacotherapeutics, Faculty of Pharmacy, Osaka Ohtani University, 3-11-1 Nishikiori-kita, Tondabayashi, Osaka, 584-8540, Japan
| | - Yukari Kubo
- Laboratory of Pathophysiology and Pharmacotherapeutics, Faculty of Pharmacy, Osaka Ohtani University, 3-11-1 Nishikiori-kita, Tondabayashi, Osaka, 584-8540, Japan
| | - Hyuma Nogusa
- Laboratory of Pathophysiology and Pharmacotherapeutics, Faculty of Pharmacy, Osaka Ohtani University, 3-11-1 Nishikiori-kita, Tondabayashi, Osaka, 584-8540, Japan
| | - Tomoka Takatani-Nakase
- Laboratory of Pathophysiology and Pharmacotherapeutics, Faculty of Pharmacy, Osaka Ohtani University, 3-11-1 Nishikiori-kita, Tondabayashi, Osaka, 584-8540, Japan.,Department of Pharmaceutics, School of Pharmacy and Pharmaceutical Sciences, Mukogawa Women's University, 11-68 Koshien-kyubancho, Nishinomiya, Hyogo, 663-8179, Japan
| | - Shujiro Okuda
- Bioinformatics, Niigata University Graduate School of Medical and Dental Sciences, 2-5274 Gakkochodori, Chuo-ku, Niigata, 951-8514, Japan
| | - Kunihiro Ueda
- Kobe Tokiwa University, 2-6-2 Otanicho, Nagata-ku, Kobe, Hyogo, 653-0838, Japan
| | - Seigo Tanaka
- Laboratory of Pathophysiology and Pharmacotherapeutics, Faculty of Pharmacy, Osaka Ohtani University, 3-11-1 Nishikiori-kita, Tondabayashi, Osaka, 584-8540, Japan.
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8
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Chu W, Yuan J, Huang L, Xiang X, Zhu H, Chen F, Chen Y, Lin J, Feng H. Valproic Acid Arrests Proliferation but Promotes Neuronal Differentiation of Adult Spinal NSPCs from SCI Rats. Neurochem Res 2015; 40:1472-86. [PMID: 26023063 DOI: 10.1007/s11064-015-1618-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2015] [Revised: 04/02/2015] [Accepted: 05/18/2015] [Indexed: 11/29/2022]
Abstract
Although the adult spinal cord contains a population of multipotent neural stem/precursor cells (NSPCs) exhibiting the potential to replace neurons, endogenous neurogenesis is very limited after spinal cord injury (SCI) because the activated NSPCs primarily differentiate into astrocytes rather than neurons. Valproic acid (VPA), a histone deacetylase inhibitor, exerts multiple pharmacological effects including fate regulation of stem cells. In this study, we cultured adult spinal NSPCs from chronic compressive SCI rats and treated with VPA. In spite of inhibiting the proliferation and arresting in the G0/G1 phase of NSPCs, VPA markedly promoted neuronal differentiation (β-tubulin III(+) cells) as well as decreased astrocytic differentiation (GFAP(+) cells). Cell cycle regulator p21(Cip/WAF1) and proneural genes Ngn2 and NeuroD1 were increased in the two processes respectively. In vivo, to minimize the possible inhibitory effects of VPA to the proliferation of NSPCs as well as avoid other neuroprotections of VPA in acute phase of SCI, we carried out a delayed intraperitoneal injection of VPA (150 mg/kg/12 h) to SCI rats from day 15 to day 22 after injury. Both of the newborn neuron marker doublecortin and the mature neuron marker neuron-specific nuclear protein were significantly enhanced after VPA treatment in the epicenter and adjacent segments of the injured spinal cord. Although the impaired corticospinal tracks had not significantly improved, Basso-Beattie-Bresnahan scores in VPA treatment group were better than control. Our study provide the first evidence that administration of VPA enhances the neurogenic potential of NSPCs after SCI and reveal the therapeutic value of delayed treatment of VPA to SCI.
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Affiliation(s)
- Weihua Chu
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, No. 29, Gaotanyan Street, Shapingba District, Chongqing, 400038, China,
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9
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Higher vulnerability and stress sensitivity of neuronal precursor cells carrying an alpha-synuclein gene triplication. PLoS One 2014; 9:e112413. [PMID: 25390032 PMCID: PMC4229205 DOI: 10.1371/journal.pone.0112413] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2013] [Accepted: 10/16/2014] [Indexed: 12/19/2022] Open
Abstract
Parkinson disease (PD) is a multi-factorial neurodegenerative disorder with loss of dopaminergic neurons in the substantia nigra and characteristic intracellular inclusions, called Lewy bodies. Genetic predisposition, such as point mutations and copy number variants of the SNCA gene locus can cause very similar PD-like neurodegeneration. The impact of altered α-synuclein protein expression on integrity and developmental potential of neuronal stem cells is largely unexplored, but may have wide ranging implications for PD manifestation and disease progression. Here, we investigated if induced pluripotent stem cell-derived neuronal precursor cells (NPCs) from a patient with Parkinson's disease carrying a genomic triplication of the SNCA gene (SNCA-Tri). Our goal was to determine if these cells these neuronal precursor cells already display pathological changes and impaired cellular function that would likely predispose them when differentiated to neurodegeneration. To achieve this aim, we assessed viability and cellular physiology in human SNCA-Tri NPCs both under normal and environmentally stressed conditions to model in vitro gene-environment interactions which may play a role in the initiation and progression of PD. Human SNCA-Tri NPCs displayed overall normal cellular and mitochondrial morphology, but showed substantial changes in growth, viability, cellular energy metabolism and stress resistance especially when challenged by starvation or toxicant challenge. Knockdown of α-synuclein in the SNCA-Tri NPCs by stably expressed short hairpin RNA (shRNA) resulted in reversal of the observed phenotypic changes. These data show for the first time that genetic alterations such as the SNCA gene triplication set the stage for decreased developmental fitness, accelerated aging, and increased neuronal cell loss. The observation of this "stem cell pathology" could have a great impact on both quality and quantity of neuronal networks and could provide a powerful new tool for development of neuroprotective strategies for PD.
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Abstract
Ubiquitin-dependent proteolysis is a major mechanism that downregulates misfolded proteins or those that have finished a programmed task. In the last two decades, neddylation has emerged as a major regulatory pathway for ubiquitination. Central to the neddylation pathway is the amyloid precursor protein (APP)-binding protein APP-BP1, which together with Uba3, plays an analogous role to the ubiquitin-activating enzyme E1 in nedd8 activation. Activated nedd8 covalently modifies and activates a major class of ubiquitin ligases called Cullin-RING ligases (CRLs). New evidence suggests that neddylation also modifies Type-1 transmembrane receptors such as APP. Here we review the functions of neddylation and summarize evidence suggesting that dysfunction of neddylation is involved in Alzheimer's disease.
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Affiliation(s)
- Yuzhi Chen
- Department of Geriatrics and Department of Neurobiology & Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
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11
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Nalivaeva NN, Turner AJ. The amyloid precursor protein: a biochemical enigma in brain development, function and disease. FEBS Lett 2013; 587:2046-54. [PMID: 23684647 DOI: 10.1016/j.febslet.2013.05.010] [Citation(s) in RCA: 170] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Revised: 05/06/2013] [Accepted: 05/06/2013] [Indexed: 12/11/2022]
Abstract
For 20 years the amyloid cascade hypothesis of Alzheimer disease (AD) has placed the amyloid-β peptide (Aβ), formed from the amyloid precursor protein (APP), centre stage in the process of neurodegeneration. However, no new therapeutic agents have reached the clinic through exploitation of the hypothesis. The APP metabolites, including Aβ, generated by its proteolytic processing, have distinct physiological functions. In particular, the cleaved intracellular domain of APP (AICD) regulates expression of several genes, including APP itself, the β-secretase BACE-1 and the Aβ-degrading enzyme, neprilysin and this transcriptional regulation involves direct promoter binding of AICD. Of the three major splice isoforms of APP (APP695, APP751, APP770), APP695 is the predominant neuronal form, from which Aβ and transcriptionally-active AICD are preferentially generated by selective processing through the amyloidogenic pathway. Despite intensive research, the normal functions of the APP isoforms remain an enigma. APP plays an important role in brain development, memory and synaptic plasticity and secreted forms of APP are neuroprotective. A fuller understanding of the physiological and pathological actions of APP and its metabolic and gene regulatory network could provide new therapeutic opportunities in neurodegeneration, including AD.
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Affiliation(s)
- Natalia N Nalivaeva
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK.
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12
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Thomson JM, Bowles V, Choi JW, Basu U, Meng Y, Stothard P, Moore S. The identification of candidate genes and SNP markers for classical bovine spongiform encephalopathy susceptibility. Prion 2012; 6:461-9. [PMID: 22918267 DOI: 10.4161/pri.21866] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Classical bovine spongiform encephalopathy is a transmissible prion disease that is fatal to cattle and is a human health risk due to its association with a strain of Creutzfeldt-Jakob disease (vCJD). Mutations to the coding region of the prion gene (PRNP) have been associated with susceptibility to transmissible spongiform encephalopathies in mammals including bovines and humans. Additional loci such as the retinoic acid receptor beta (RARB) and stathmin like 2 (STMN2) have also been associated with disease risk. The objective of this study was to refine previously identified regions associated with BSE susceptibility and to identify positional candidate genes and genetic variation that may be involved with the progression of classical BSE. The samples included 739 samples of either BSE infected animals (522 animals) or non-infected controls (207 animals). These were tested using a custom SNP array designed to narrow previously identified regions of importance in bovine genome. Thirty one single nucleotide polymorphisms were identified at p < 0.05 and a minor allele frequency greater than 5%. The chromosomal regions identified and the positional and functional candidate genes and regulatory elements identified within these regions warrant further research.
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Affiliation(s)
- Jennifer M Thomson
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, AB Canada
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13
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Amyloid precursor protein binding protein-1 knockdown reduces neuronal differentiation in fetal neural stem cells. Neuroreport 2012; 23:61-6. [PMID: 22182960 DOI: 10.1097/wnr.0b013e32834e7d4f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Amyloid precursor protein binding protein-1 (APP-BP1) was first identified as an interacting protein of APP. In this study, we explored whether APP-BP1 plays a role in neuronal differentiation of fetal neural stem cells. APP-BP1 knockdown by small interfering RNA treatment was found to downregulate neuronal differentiation and to upregulate APP intracellular domain production from APP in fetal neural stem cells. Furthermore, the change in gene expression profiles was systemically examined by DNA microarray. The expression of several genes including ephrin A2 was upregulated by APP-BP1 knockdown as assessed with DNA microarray and reverse transcriptase-polymerase chain reaction. Taken together, our results suggest that APP-BP1 modulates neuronal differentiation by altering gene expression profiles in fetal neural stem cells.
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14
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Lu J, Lian G, Zhou H, Esposito G, Steardo L, Delli-Bovi LC, Hecht JL, Lu QR, Sheen V. OLIG2 over-expression impairs proliferation of human Down syndrome neural progenitors. Hum Mol Genet 2012; 21:2330-40. [PMID: 22343408 DOI: 10.1093/hmg/dds052] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
Mental retardation and early Alzheimer's disease (AD) have generally been attributed to progressive neuronal loss in the developing and mature Down syndrome (DS) brain. However, reduced neuronal production during development could also contribute to the smaller brain size and simplified gyral patterning seen in this disorder. Here, we show impairments in proliferation within the ventricular zone (VZ) of early DS fetal cortex and in cultured early passage DS human neural progenitors (HNPs). We find that the reduced proliferative rates correspond temporally with increased expression of the chromosome 21 (HSA21) associated, oligodendrocyte transcription factor OLIG2 at 14-18 weeks gestational age (GA) (period of neurogenesis). Moreover, the DS HNPs adopt more oligodendrocyte-specific features including increased oligodendrocyte marker expression, as well as a reduction in KCNA3 potassium channel expression and function. We further show that OLIG2 inhibition or over-expression regulates potassium channel expression levels and that activation or inhibition of these channels influences the rate of progenitor proliferation. Finally, neural progenitors from Olig2 over-expressing transgenic mice exhibit these same impairments in proliferation and potassium channel expression. These findings suggest that OLIG2 over-expression inhibits neural progenitor proliferation through changes in potassium channel activity, thereby contributing to the reduced neuronal numbers and brain size in DS.
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Affiliation(s)
- Jie Lu
- Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA 02115, USA
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