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Okechukwu NG, Klein C, Jamann H, Maitre M, Patte-Mensah C, Mensah-Nyagan AG. Monomeric Amyloid Peptide-induced Toxicity in Human Oligodendrocyte Cell Line and Mouse Brain Primary Mixed-glial Cell Cultures: Evidence for a Neuroprotective Effect of Neurosteroid 3α-O-allyl-allopregnanolone. Neurotox Res 2024; 42:37. [PMID: 39102123 DOI: 10.1007/s12640-024-00715-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 04/18/2024] [Accepted: 07/22/2024] [Indexed: 08/06/2024]
Abstract
Amyloid-peptide (Aβ) monomeric forms (ABM) occurring in presymptomatic Alzheimer's disease (AD) brain are thought to be devoid of neurotoxicity while the transition/aggregation of ABM into oligomers is determinant for Aβ-induced toxicity since Aβ is predominantly monomeric up to 3 µM and aggregates over this concentration. However, recent imaging and/or histopathological investigations revealed alterations of myelin in prodromal AD brain in absence of aggregated Aβ oligomers, suggesting that ABM may induce toxicity in myelin-producing cells in early AD-stages. To check this hypothesis, here we studied ABM effects on the viability of the Human oligodendrocyte cell line (HOG), a reliable oligodendrocyte model producing myelin proteins. Furthermore, to mimic closely interactions between oligodendrocytes and other glial cells regulating myelination, we investigated also ABM effects on mouse brain primary mixed-glial cell cultures. Various methods were combined to show that ABM concentrations (600 nM-1 µM), extremely lower than 3 µM, significantly decreased HOG cell and mouse brain primary mixed-glial cell survival. Interestingly, flow-cytometry studies using specific cell-type markers demonstrated that oligodendrocytes represent the most vulnerable glial cell population affected by ABM toxicity. Our work also shows that the neurosteroid 3α-O-allyl-allopregnanolone BR351 (250 and 500 nM) efficiently prevented ABM-induced HOG and brain primary glial cell toxicity. Bicuculline (50-100 nM), the GABA-A-receptor antagonist, was unable to block/reduce BR351 effect against ABM-induced HOG and primary glial cell toxicity, suggesting that BR351-evoked neuroprotection of these cells may not depend on GABA-A-receptor allosterically modulated by neurosteroids. Altogether, our results suggest that further exploration of BR351 therapeutic potential may offer interesting perspectives to develop effective neuroprotective strategies.
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Affiliation(s)
- Nwife Getrude Okechukwu
- Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, INSERM U1119, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Bâtiment CRBS de la Faculté de Médecine, 1 rue Eugène Boeckel, 67 000, Strasbourg, France
| | - Christian Klein
- Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, INSERM U1119, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Bâtiment CRBS de la Faculté de Médecine, 1 rue Eugène Boeckel, 67 000, Strasbourg, France
- Centre d'Investigation Clinique de Strasbourg (CIC), Equipe CIC-Recherche Translationnelle Neuro, INSERM 1434, Université de Strasbourg, Bâtiment CRBS, 1 rue Eugène Boeckel, 67000, Strasbourg, France
| | - Hélène Jamann
- Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, INSERM U1119, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Bâtiment CRBS de la Faculté de Médecine, 1 rue Eugène Boeckel, 67 000, Strasbourg, France
- Centre d'Investigation Clinique de Strasbourg (CIC), Equipe CIC-Recherche Translationnelle Neuro, INSERM 1434, Université de Strasbourg, Bâtiment CRBS, 1 rue Eugène Boeckel, 67000, Strasbourg, France
| | - Michel Maitre
- Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, INSERM U1119, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Bâtiment CRBS de la Faculté de Médecine, 1 rue Eugène Boeckel, 67 000, Strasbourg, France
- Centre d'Investigation Clinique de Strasbourg (CIC), Equipe CIC-Recherche Translationnelle Neuro, INSERM 1434, Université de Strasbourg, Bâtiment CRBS, 1 rue Eugène Boeckel, 67000, Strasbourg, France
| | - Christine Patte-Mensah
- Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, INSERM U1119, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Bâtiment CRBS de la Faculté de Médecine, 1 rue Eugène Boeckel, 67 000, Strasbourg, France
- Centre d'Investigation Clinique de Strasbourg (CIC), Equipe CIC-Recherche Translationnelle Neuro, INSERM 1434, Université de Strasbourg, Bâtiment CRBS, 1 rue Eugène Boeckel, 67000, Strasbourg, France
| | - Ayikoé-Guy Mensah-Nyagan
- Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, INSERM U1119, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Bâtiment CRBS de la Faculté de Médecine, 1 rue Eugène Boeckel, 67 000, Strasbourg, France.
- Centre d'Investigation Clinique de Strasbourg (CIC), Equipe CIC-Recherche Translationnelle Neuro, INSERM 1434, Université de Strasbourg, Bâtiment CRBS, 1 rue Eugène Boeckel, 67000, Strasbourg, France.
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2
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Langeland JA, Baumann L, DeYoung EM, Varella RA, Mwenda N, Aguirre A, Moore DB. Early Animal Origin of BACE1 APP/Aβ Proteolytic Function. BIOLOGY 2024; 13:320. [PMID: 38785802 PMCID: PMC11117577 DOI: 10.3390/biology13050320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 04/24/2024] [Accepted: 04/30/2024] [Indexed: 05/25/2024]
Abstract
Alzheimer's disease is characterized, in part, by the accumulation of β-amyloid (Aβ) in the brain. Aβ is produced via the proteolysis of APP by BACE1 and γ-secretase. Since BACE1 is the rate-limiting enzyme in the production of Aβ, and a target for therapeutics, it is of interest to know when its proteolytic function evolved and for what purpose. Here, we take a functional evolutionary approach to show that BACE1 likely evolved from a gene duplication event near the base of the animal clade and that BACE1 APP/Aβ proteolytic function evolved during early animal diversification, hundreds of millions of years before the evolution of the APP/Aβ substrate. Our examination of BACE1 APP/Aβ proteolytic function includes cnidarians, ctenophores, and choanoflagellates. The most basal BACE1 ortholog is found in cnidarians, while ctenophores, placozoa, and choanoflagellates have genes equally orthologous to BACE1 and BACE2. BACE1 from a cnidarian (Hydra) can cleave APP to release Aβ, pushing back the date of the origin of its function to near the origin of animals. We tested more divergent BACE1/2 genes from a ctenophore (Mnemiopsis) and a choanoflagellate (Monosiga), and neither has this activity. These findings indicate that the specific proteolytic function of BACE1 evolved during the very earliest diversification of animals, most likely after a gene-duplication event.
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Affiliation(s)
| | | | | | | | | | | | - D. Blaine Moore
- Department of Biology, Kalamazoo College, 1200 Academy Street, Kalamazoo, MI 49006, USA
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Lardelli M, Baer L, Hin N, Allen A, Pederson SM, Barthelson K. The Use of Zebrafish in Transcriptome Analysis of the Early Effects of Mutations Causing Early Onset Familial Alzheimer's Disease and Other Inherited Neurodegenerative Conditions. J Alzheimers Dis 2024; 99:S367-S381. [PMID: 37742650 DOI: 10.3233/jad-230522] [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: 09/26/2023]
Abstract
The degree to which non-human animals can be used to model Alzheimer's disease is a contentious issue, particularly as there is still widespread disagreement regarding the pathogenesis of this neurodegenerative dementia. The currently popular transgenic models are based on artificial expression of genes mutated in early onset forms of familial Alzheimer's disease (EOfAD). Uncertainty regarding the veracity of these models led us to focus on heterozygous, single mutations of endogenous genes (knock-in models) as these most closely resemble the genetic state of humans with EOfAD, and so incorporate the fewest assumptions regarding pathological mechanism. We have generated a number of lines of zebrafish bearing EOfAD-like and non-EOfAD-like mutations in genes equivalent to human PSEN1, PSEN2, and SORL1. To analyze the young adult brain transcriptomes of these mutants, we exploited the ability of zebrafish to produce very large families of simultaneous siblings composed of a variety of genotypes and raised in a uniform environment. This "intra-family" analysis strategy greatly reduced genetic and environmental "noise" thereby allowing detection of subtle changes in gene sets after bulk RNA sequencing of entire brains. Changes to oxidative phosphorylation were predicted for all EOfAD-like mutations in the three genes studied. Here we describe some of the analytical lessons learned in our program combining zebrafish genome editing with transcriptomics to understand the molecular pathologies of neurodegenerative disease.
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Affiliation(s)
- Michael Lardelli
- Alzheimer's Disease Genetics Laboratory, The University of Adelaide, Adelaide, SA, Australia
| | - Lachlan Baer
- Alzheimer's Disease Genetics Laboratory, The University of Adelaide, Adelaide, SA, Australia
| | - Nhi Hin
- Alkahest Inc., San Carlos, CA, USA
| | - Angel Allen
- Alzheimer's Disease Genetics Laboratory, The University of Adelaide, Adelaide, SA, Australia
| | - Stephen Martin Pederson
- Black Ochre Data Labs, Indigenous Genomics, Telethon Kinds Institute, Adelaide, SA, Australia
- John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia
| | - Karissa Barthelson
- Alzheimer's Disease Genetics Laboratory, The University of Adelaide, Adelaide, SA, Australia
- Childhood Dementia Research Group, College of Medicine and Public Health, Flinders Health and Medical Research Institute, Flinders University, Bedford Park, SA, Australia
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4
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Jeong H, Shin H, Hong S, Kim Y. Physiological Roles of Monomeric Amyloid-β and Implications for Alzheimer's Disease Therapeutics. Exp Neurobiol 2022; 31:65-88. [PMID: 35673997 PMCID: PMC9194638 DOI: 10.5607/en22004] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 03/26/2022] [Accepted: 03/30/2022] [Indexed: 12/23/2022] Open
Abstract
Alzheimer's disease (AD) progressively inflicts impairment of synaptic functions with notable deposition of amyloid-β (Aβ) as senile plaques within the extracellular space of the brain. Accordingly, therapeutic directions for AD have focused on clearing Aβ plaques or preventing amyloidogenesis based on the amyloid cascade hypothesis. However, the emerging evidence suggests that Aβ serves biological roles, which include suppressing microbial infections, regulating synaptic plasticity, promoting recovery after brain injury, sealing leaks in the blood-brain barrier, and possibly inhibiting the proliferation of cancer cells. More importantly, these functions were found in in vitro and in vivo investigations in a hormetic manner, that is to be neuroprotective at low concentrations and pathological at high concentrations. We herein summarize the physiological roles of monomeric Aβ and current Aβ-directed therapies in clinical trials. Based on the evidence, we propose that novel therapeutics targeting Aβ should selectively target Aβ in neurotoxic forms such as oligomers while retaining monomeric Aβ in order to preserve the physiological functions of Aβ monomers.
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Affiliation(s)
- Hyomin Jeong
- Division of Integrated Science and Engineering, Underwood International College, Yonsei University, Incheon 21983, Korea
- Department of Pharmacy, College of Pharmacy, Yonsei University, Incheon 21983, Korea
- Yonsei Institute of Pharmaceutical Sciences, College of Pharmacy, Yonsei University, Incheon 21983, Korea
| | - Heewon Shin
- Department of Pharmacy, College of Pharmacy, Yonsei University, Incheon 21983, Korea
- Yonsei Institute of Pharmaceutical Sciences, College of Pharmacy, Yonsei University, Incheon 21983, Korea
| | - Seungpyo Hong
- Department of Pharmacy, College of Pharmacy, Yonsei University, Incheon 21983, Korea
- Yonsei Frontier Lab, Yonsei University, Seoul 03722, Korea
- Division of Pharmaceutical Sciences, School of Pharmacy, University of Wisconsin-Madison, Madison, WI 53705, USA
- Wisconsin Center for NanoBioSystems, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - YoungSoo Kim
- Division of Integrated Science and Engineering, Underwood International College, Yonsei University, Incheon 21983, Korea
- Department of Pharmacy, College of Pharmacy, Yonsei University, Incheon 21983, Korea
- Yonsei Institute of Pharmaceutical Sciences, College of Pharmacy, Yonsei University, Incheon 21983, Korea
- Yonsei Frontier Lab, Yonsei University, Seoul 03722, Korea
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Barthelson K, Newman M, Lardelli M. Brain transcriptomes of zebrafish and mouse Alzheimer's disease knock-in models imply early disrupted energy metabolism. Dis Model Mech 2021; 15:273566. [PMID: 34842276 PMCID: PMC8807579 DOI: 10.1242/dmm.049187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Accepted: 11/17/2021] [Indexed: 11/21/2022] Open
Abstract
Energy production is the most fundamentally important cellular activity supporting all other functions, particularly in highly active organs, such as brains. Here, we summarise transcriptome analyses of young adult (pre-disease) brains from a collection of 11 early-onset familial Alzheimer's disease (EOFAD)-like and non-EOFAD-like mutations in three zebrafish genes. The one cellular activity consistently predicted as affected by only the EOFAD-like mutations is oxidative phosphorylation, which produces most of the energy of the brain. All the mutations were predicted to affect protein synthesis. We extended our analysis to knock-in mouse models of APOE alleles and found the same effect for the late onset Alzheimer's disease risk allele ε4. Our results support a common molecular basis for the initiation of the pathological processes leading to both early and late onset forms of Alzheimer's disease, and illustrate the utility of zebrafish and knock-in single EOFAD mutation models for understanding the causes of this disease. Summary: Young adult zebrafish mutants and a mouse model of a genetic variant promoting early- and late-onset Alzheimer's disease, respectively, share changes in brain gene expression, indicating disturbance of oxidative phosphorylation.
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Affiliation(s)
- Karissa Barthelson
- Alzheimer's Disease Genetics Laboratory, School of Biological Sciences, University of Adelaide, North Terrace, Adelaide, SA 5005, Australia
| | - Morgan Newman
- Alzheimer's Disease Genetics Laboratory, School of Biological Sciences, University of Adelaide, North Terrace, Adelaide, SA 5005, Australia
| | - Michael Lardelli
- Alzheimer's Disease Genetics Laboratory, School of Biological Sciences, University of Adelaide, North Terrace, Adelaide, SA 5005, Australia
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Barthelson K, Dong Y, Newman M, Lardelli M. PRESENILIN 1 Mutations Causing Early-Onset Familial Alzheimer's Disease or Familial Acne Inversa Differ in Their Effects on Genes Facilitating Energy Metabolism and Signal Transduction. J Alzheimers Dis 2021; 82:327-347. [PMID: 34024832 DOI: 10.3233/jad-210128] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND The most common cause of early-onset familial Alzheimer's disease (EOfAD) is mutations in PRESENILIN 1 (PSEN1) allowing production of mRNAs encoding full-length, but mutant, proteins. In contrast, a single known frameshift mutation in PSEN1 causes familial acne inversa (fAI) without EOfAD. The molecular consequences of heterozygosity for these mutation types, and how they cause completely different diseases, remains largely unexplored. OBJECTIVE To analyze brain transcriptomes of young adult zebrafish to identify similarities and differences in the effects of heterozygosity for psen1 mutations causing EOfAD or fAI. METHODS RNA sequencing was performed on mRNA isolated from the brains of a single family of 6-month-old zebrafish siblings either wild type or possessing a single, heterozygous EOfAD-like or fAI-like mutation in their endogenous psen1 gene. RESULTS Both mutations downregulate genes encoding ribosomal subunits, and upregulate genes involved in inflammation. Genes involved in energy metabolism appeared significantly affected only by the EOfAD-like mutation, while genes involved in Notch, Wnt and neurotrophin signaling pathways appeared significantly affected only by the fAI-like mutation. However, investigation of direct transcriptional targets of Notch signaling revealed possible increases in γ-secretase activity due to heterozygosity for either psen1 mutation. Transcriptional adaptation due to the fAI-like frameshift mutation was evident. CONCLUSION We observed both similar and contrasting effects on brain transcriptomes of the heterozygous EOfAD-like and fAI-like mutations. The contrasting effects may illuminate how these mutation types cause distinct diseases.
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Affiliation(s)
- Karissa Barthelson
- Alzheimer's Disease Genetics Laboratory, School of Biological Sciences, University of Adelaide, North Terrace, Adelaide, SA, Australia
| | - Yang Dong
- Alzheimer's Disease Genetics Laboratory, School of Biological Sciences, University of Adelaide, North Terrace, Adelaide, SA, Australia
| | - Morgan Newman
- Alzheimer's Disease Genetics Laboratory, School of Biological Sciences, University of Adelaide, North Terrace, Adelaide, SA, Australia
| | - Michael Lardelli
- Alzheimer's Disease Genetics Laboratory, School of Biological Sciences, University of Adelaide, North Terrace, Adelaide, SA, Australia
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Fülöp T, Munawara U, Larbi A, Desroches M, Rodrigues S, Catanzaro M, Guidolin A, Khalil A, Bernier F, Barron AE, Hirokawa K, Beauregard PB, Dumoulin D, Bellenger JP, Witkowski JM, Frost E. Targeting Infectious Agents as a Therapeutic Strategy in Alzheimer's Disease. CNS Drugs 2020; 34:673-695. [PMID: 32458360 PMCID: PMC9020372 DOI: 10.1007/s40263-020-00737-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Alzheimer's disease (AD) is the most prevalent dementia in the world. Its cause(s) are presently largely unknown. The most common explanation for AD, now, is the amyloid cascade hypothesis, which states that the cause of AD is senile plaque formation by the amyloid β peptide, and the formation of neurofibrillary tangles by hyperphosphorylated tau. A second, burgeoning theory by which to explain AD is based on the infection hypothesis. Much experimental and epidemiological data support the involvement of infections in the development of dementia. According to this mechanism, the infection either directly or via microbial virulence factors precedes the formation of amyloid β plaques. The amyloid β peptide, possessing antimicrobial properties, may be beneficial at an early stage of AD, but becomes detrimental with the progression of the disease, concomitantly with alterations to the innate immune system at both the peripheral and central levels. Infection results in neuroinflammation, leading to, and sustained by, systemic inflammation, causing eventual neurodegeneration, and the senescence of the immune cells. The sources of AD-involved microbes are various body microbiome communities from the gut, mouth, nose, and skin. The infection hypothesis of AD opens a vista to new therapeutic approaches, either by treating the infection itself or modulating the immune system, its senescence, or the body's metabolism, either separately, in parallel, or in a multi-step way.
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Affiliation(s)
- Tamàs Fülöp
- Geriatric Division, Department of Medicine, Faculty of Medicine and Health Sciences, Research Center on Aging, University of Sherbrooke, 3001, 12th Avenue North, Sherbrooke, QC, J1H 5N4, Canada.
| | - Usma Munawara
- Geriatric Division, Department of Medicine, Faculty of Medicine and Health Sciences, Research Center on Aging, University of Sherbrooke, 3001, 12th Avenue North, Sherbrooke, QC, J1H 5N4, Canada
| | - Anis Larbi
- Singapore Immunology Network (SIgN), Agency for Science Technology and Research (A*STAR), Immunos Building, Biopolis, Singapore, Singapore
- Department of Biology, Faculty of Science, University Tunis El Manar, Tunis, Tunisia
| | - Mathieu Desroches
- MathNeuro Team, Inria Sophia Antipolis Méditerranée, Valbonne, France
- Université Côte d'Azur, Nice, France
| | - Serafim Rodrigues
- Ikerbasque, The Basque Foundation for Science, Bilbao, Spain
- BCAM, The Basque Center for Applied Mathematics, Bilbao, Spain
| | - Michele Catanzaro
- Geriatric Division, Department of Medicine, Faculty of Medicine and Health Sciences, Research Center on Aging, University of Sherbrooke, 3001, 12th Avenue North, Sherbrooke, QC, J1H 5N4, Canada
- Department of Drug Sciences, University of Pavia, Pavia, Italy
| | - Andrea Guidolin
- BCAM, The Basque Center for Applied Mathematics, Bilbao, Spain
| | - Abdelouahed Khalil
- Geriatric Division, Department of Medicine, Faculty of Medicine and Health Sciences, Research Center on Aging, University of Sherbrooke, 3001, 12th Avenue North, Sherbrooke, QC, J1H 5N4, Canada
| | - François Bernier
- Next Generation Science Institute, Morinaga Milk Industry Co., Ltd., Zama, Japan
| | - Annelise E Barron
- Department of Bioengineering, Stanford School of Medicine, Stanford, CA, USA
| | - Katsuiku Hirokawa
- Department of Pathology, Institute of Health and Life Science, Tokyo and Nito-memory Nakanosogo Hospital, Tokyo Med. Dent. University, Tokyo, Japan
| | - Pascale B Beauregard
- Department of Biology, Faculty of Sciences, University of Sherbrooke, Sherbrooke, QC, Canada
| | - David Dumoulin
- Department of Biology, Faculty of Sciences, University of Sherbrooke, Sherbrooke, QC, Canada
| | - Jean-Philippe Bellenger
- Department of Chemistry, Faculty of Sciences, University of Sherbrooke, Sherbrooke, QC, Canada
| | - Jacek M Witkowski
- Department of Pathophysiology, Medical University of Gdansk, Gdansk, Poland
| | - Eric Frost
- Department of Microbiology and Infectious diseases, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, QC, Canada
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Accelerated brain aging towards transcriptional inversion in a zebrafish model of the K115fs mutation of human PSEN2. PLoS One 2020; 15:e0227258. [PMID: 31978074 PMCID: PMC6980398 DOI: 10.1371/journal.pone.0227258] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 12/16/2019] [Indexed: 12/26/2022] Open
Abstract
Background The molecular changes involved in Alzheimer’s disease (AD) progression remain unclear since we cannot easily access antemortem human brains. Some non-mammalian vertebrates such as the zebrafish preserve AD-relevant transcript isoforms of the PRESENILIN genes lost from mice and rats. One example is PS2V, the alternative transcript isoform of the PSEN2 gene. PS2V is induced by hypoxia/oxidative stress and shows increased expression in late onset, sporadic AD brains. A unique, early onset familial AD mutation of PSEN2, K115fs, mimics the PS2V coding sequence suggesting that forced, early expression of PS2V-like isoforms may contribute to AD pathogenesis. Here we use zebrafish to model the K115fs mutation to investigate the effects of forced PS2V-like expression on the transcriptomes of young adult and aged adult brains. Methods We edited the zebrafish genome to model the K115fs mutation. To explore its effects at the molecular level, we analysed the brain transcriptome and proteome of young (6-month-old) and aged (24-month-old) wild type and heterozygous mutant female sibling zebrafish. Finally, we used gene co-expression network analysis (WGCNA) to compare molecular changes in the brains of these fish to human AD. Results Young heterozygous mutant fish show transcriptional changes suggesting accelerated brain aging and increased glucocorticoid signalling. These early changes precede a transcriptional ‘inversion’ that leads to glucocorticoid resistance and other likely pathological changes in aged heterozygous mutant fish. Notably, microglia-associated immune responses regulated by the ETS transcription factor family are altered in both our zebrafish mutant model and in human AD. The molecular changes we observe in aged heterozygous mutant fish occur without obvious histopathology and possibly in the absence of Aβ. Conclusions Our results suggest that forced expression of a PS2V-like isoform contributes to immune and stress responses favouring AD pathogenesis. This highlights the value of our zebrafish genetic model for exploring molecular mechanisms involved in AD pathogenesis.
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Wang L, Liu J, Wang Q, Jiang H, Zeng L, Li Z, Liu R. MicroRNA-200a-3p Mediates Neuroprotection in Alzheimer-Related Deficits and Attenuates Amyloid-Beta Overproduction and Tau Hyperphosphorylation via Coregulating BACE1 and PRKACB. Front Pharmacol 2019; 10:806. [PMID: 31379578 PMCID: PMC6658613 DOI: 10.3389/fphar.2019.00806] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 06/21/2019] [Indexed: 12/16/2022] Open
Abstract
Alzheimer’s disease (AD) is characterized by two landmark pathologies, the overproduction of amyloid-beta peptides (Aβ), predominated by the β-amyloid protein precursor cleaving enzyme 1 (BACE1), and hyperphosphorylation of the microtubule protein, tau, because of an imbalance in a kinase/phosphatase system that involves the activation of the protein kinase A (PKA). Current evidence indicates that brain microRNAs participate in multiple aspects of AD pathology. Here, the role and underlying molecular mechanisms of microRNA-200a-3p (miR-200a-3p) in mediating neuroprotection against AD-related deficits were investigated. The expression of miR-200a-3p was measured in the hippocampus of APP/PS1 and SAMP8 mice and in an AD cell model in vitro, as well as in blood plasma extracted from AD patients. The targets of miR-200a-3p were determined using bioinformatics and dual-luciferase assay analyses. In addition, cell apoptosis was detected using flow cytometry, and related protein levels were measured using Western blot and enzyme-linked immunosorbent assay (ELISA) techniques. miR-200a-3p was confirmed to be depressed in microarray miRNA profile analysis in vitro and in vivo, suggesting that miR-200a-3p is a potential biomarker of AD. Subsequently, miR-200a-3p was demonstrated to inhibit cell apoptosis accompanied by the inactivation of the Bax/caspase-3 axis and downregulation of Aβ1-42 and tau phosphorylation levels in vitro. Further mechanistic studies revealed that miR-200a-3p reduced the production of Aβ1-42 and decreased hyperphosphorylation of tau by regulating the protein translocation of BACE1 and the protein kinase cAMP-activated catalytic subunit beta (PRKACB) associated with the three prime untranslated regions, respectively. Importantly, the function of miR-200a-3p was reversed by overexpression of BACE1 or PRKACB in cultured cells. This resulted in an elevation in cell apoptosis and increases in Aβ1-42 and tau hyperphosphorylation levels, involving the epitopes threonine 205 and serine 202, 214, 396, and 356, the favorable phosphorylated sites of PKA. In conclusion, our study suggests that miR-200a-3p is implicated in the pathology of AD, exerting neuroprotective effects against Aβ-induced toxicity by two possible mechanisms: one involving the inhibition of Aβ overproduction via suppression of the expression of BACE1 and synergistically decreasing the hyperphosphorylation of tau via attenuation of the expression of PKA.
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Affiliation(s)
- Linlin Wang
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China.,Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Jianghong Liu
- Department of Neurology, Xuan Wu Hospital, Capital Medical University, Beijing, China
| | - Qian Wang
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Hailun Jiang
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Li Zeng
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China.,Department of Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang, China
| | - Zhuorong Li
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Rui Liu
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
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Moir RD, Tanzi RE. Low Evolutionary Selection Pressure in Senescence Does Not Explain the Persistence of Aβ in the Vertebrate Genome. Front Aging Neurosci 2019; 11:70. [PMID: 30983989 PMCID: PMC6447958 DOI: 10.3389/fnagi.2019.00070] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 03/12/2019] [Indexed: 01/08/2023] Open
Abstract
The argument is frequently made that the amyloid-β protein (Aβ) persists in the human genome because Alzheimer's disease (AD) primarily afflicts individuals over reproductive age and, therefore, there is low selective pressure for the peptide's elimination or modification. This argument is an important premise for AD amyloidosis models and therapeutic strategies that characterize Aβ as a functionless and intrinsically pathological protein. Here, we review if evolutionary theory and data on the genetics and biology of Aβ are consistent with low selective pressure for the peptide's expression in senescence. Aβ is an ancient neuropeptide expressed across vertebrates. Consistent with unusually high evolutionary selection constraint, the human Aβ sequence is shared by a majority of vertebrate species and has been conserved across at least 400 million years. Unlike humans, the overwhelming majority of vertebrate species do not cease reproduction in senescence and selection pressure is maintained into old age. Hence, low selective pressure in senescence does not explain the persistence of Aβ across the vertebrate genome. The "Grandmother hypothesis" (GMH) is the prevailing model explaining the unusual extended postfertile period of humans. In the GMH, high risk associated with birthing in old age has lead to early cessation of reproduction and a shift to intergenerational care of descendants. The rechanneling of resources to grandchildren by postreproductive individuals increases reproductive success of descendants. In the GMH model, selection pressure does not end following menopause. Thus, evolutionary models and phylogenetic data are not consistent with the absence of reproductive selection pressure for Aβ among aged vertebrates, including humans. Our analysis suggests an alternative evolutionary model for the persistence of Aβ in the vertebrate genome. Aβ has recently been identified as an antimicrobial effector molecule of innate immunity. High conservation across the Chordata phylum is consistent with strong positive selection pressure driving human Aβ's remarkable evolutionary longevity. Ancient origins and widespread conservation suggest the human Aβ sequence is highly optimized for its immune role. We detail our analysis and discuss how the emerging "Antimicrobial Protection Hypothesis" of AD may provide insights into possible evolutionary roles for Aβ in infection, aging, and disease etiology.
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Affiliation(s)
- Robert D. Moir
- Genetics and Aging Research Unit, Department of Neurology, MassGeneral Institute for Neurodegenerative Disease, Harvard Medical School – Massachusetts General Hospital, Boston, MA, United States
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11
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Lumsden AL, Rogers JT, Majd S, Newman M, Sutherland GT, Verdile G, Lardelli M. Dysregulation of Neuronal Iron Homeostasis as an Alternative Unifying Effect of Mutations Causing Familial Alzheimer's Disease. Front Neurosci 2018; 12:533. [PMID: 30150923 PMCID: PMC6099262 DOI: 10.3389/fnins.2018.00533] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 07/16/2018] [Indexed: 12/12/2022] Open
Abstract
The overwhelming majority of dominant mutations causing early onset familial Alzheimer’s disease (EOfAD) occur in only three genes, PSEN1, PSEN2, and APP. An effect-in-common of these mutations is alteration of production of the APP-derived peptide, amyloid β (Aβ). It is this key fact that underlies the authority of the Amyloid Hypothesis that has informed Alzheimer’s disease research for over two decades. Any challenge to this authority must offer an alternative explanation for the relationship between the PSEN genes and APP. In this paper, we explore one possible alternative relationship – the dysregulation of cellular iron homeostasis as a common effect of EOfAD mutations in these genes. This idea is attractive since it provides clear connections between EOfAD mutations and major characteristics of Alzheimer’s disease such as dysfunctional mitochondria, vascular risk factors/hypoxia, energy metabolism, and inflammation. We combine our ideas with observations by others to describe a “Stress Threshold Change of State” model of Alzheimer’s disease that may begin to explain the existence of both EOfAD and late onset sporadic (LOsAD) forms of the disease. Directing research to investigate the role of dysregulation of iron homeostasis in EOfAD may be a profitable way forward in our struggle to understand this form of dementia.
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Affiliation(s)
- Amanda L Lumsden
- College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia.,South Australian Health and Medical Research Institute, Adelaide, SA, Australia
| | - Jack T Rogers
- Neurochemistry Laboratory, Department of Psychiatry-Neuroscience, Massachusetts General Hospital (East), Harvard Medical School, Harvard University, Charlestown, MA, United States
| | - Shohreh Majd
- Neuronal Injury and Repair Laboratory, Centre for Neuroscience, College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia
| | - Morgan Newman
- Centre for Molecular Pathology, School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Greg T Sutherland
- Discipline of Pathology, Sydney Medical School, University of Sydney, Sydney, NSW, Australia
| | - Giuseppe Verdile
- School of Pharmacy and Biomedical Sciences, Faculty of Health Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, WA, Australia
| | - Michael Lardelli
- Centre for Molecular Pathology, School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
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An F, Gong G, Wang Y, Bian M, Yu L, Wei C. MiR-124 acts as a target for Alzheimer's disease by regulating BACE1. Oncotarget 2017; 8:114065-114071. [PMID: 29371969 PMCID: PMC5768386 DOI: 10.18632/oncotarget.23119] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2017] [Accepted: 11/03/2017] [Indexed: 12/23/2022] Open
Abstract
Although large numbers of microRNAs (miRNAs) expressed in Alzheimer disease (AD) have been detected, their functions and mechanisms of regulation remain to be fully clarified. Beta-site Amyloid precursor protein Cleaving Enzyme 1 (BACE1) has been one of the prime therapeutic targets for AD. Here, we identified that miR-124 levels are gradually decreased in AD. In addition, we demonstrated that miR-124 suppresses BACE1 expression by directly targeting the 3′UTR of Bace1 mRNA in vitro. Inhibition of miR-124 significantly increased BACE1 levels in neuronal cells. In contrast, miR-124 overexpression significantly suppressed BACE1 expression in cells. And finally we determined that downregulation of miR-124 alleviated Aβ-induced viability inhibition and decreased apoptosis in SH-SY5Y cells. Our results demonstrated that miR-124 is a potent negative regulator of BACE1 in the cellular AD phenotype and might be involved in the pathogenesis of AD.
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Affiliation(s)
- Fengmao An
- Medicinal Chemistry and Pharmacology Institute, Inner Mongolia University for The Nationalities, Tongliao, Inner Mongolia, P.R. China.,Inner Mongolia Key Laboratory of Mongolian Medicine Pharmacology for Cardio-Cerebral Vascular System, Tongliao, Inner Mongolia, P.R. China
| | - Guohua Gong
- Medicinal Chemistry and Pharmacology Institute, Inner Mongolia University for The Nationalities, Tongliao, Inner Mongolia, P.R. China.,Inner Mongolia Key Laboratory of Mongolian Medicine Pharmacology for Cardio-Cerebral Vascular System, Tongliao, Inner Mongolia, P.R. China.,First Clinical Medical of Inner Mongolia University for Nationalities, Tongliao, Inner Mongolia, P.R. China
| | - Yu Wang
- Medicinal Chemistry and Pharmacology Institute, Inner Mongolia University for The Nationalities, Tongliao, Inner Mongolia, P.R. China.,Inner Mongolia Key Laboratory of Mongolian Medicine Pharmacology for Cardio-Cerebral Vascular System, Tongliao, Inner Mongolia, P.R. China
| | - Ming Bian
- Medicinal Chemistry and Pharmacology Institute, Inner Mongolia University for The Nationalities, Tongliao, Inner Mongolia, P.R. China.,Inner Mongolia Key Laboratory of Mongolian Medicine Pharmacology for Cardio-Cerebral Vascular System, Tongliao, Inner Mongolia, P.R. China
| | - Lijun Yu
- Medicinal Chemistry and Pharmacology Institute, Inner Mongolia University for The Nationalities, Tongliao, Inner Mongolia, P.R. China.,Inner Mongolia Key Laboratory of Mongolian Medicine Pharmacology for Cardio-Cerebral Vascular System, Tongliao, Inner Mongolia, P.R. China
| | - Chengxi Wei
- Medicinal Chemistry and Pharmacology Institute, Inner Mongolia University for The Nationalities, Tongliao, Inner Mongolia, P.R. China.,Inner Mongolia Key Laboratory of Mongolian Medicine Pharmacology for Cardio-Cerebral Vascular System, Tongliao, Inner Mongolia, P.R. China
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13
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Gong G, An F, Wang Y, Bian M, Yu LJ, Wei C. miR-15b represses BACE1 expression in sporadic Alzheimer's disease. Oncotarget 2017; 8:91551-91557. [PMID: 29207665 PMCID: PMC5710945 DOI: 10.18632/oncotarget.21177] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 08/06/2017] [Indexed: 12/31/2022] Open
Abstract
Beta-site Amyloid precursor protein Cleaving Enzyme 1 (BACE1) is conceived as a potential target for therapies against Alzheimer disease (AD). MicroRNAs (miRNAs) are small non-coding RNAs that negatively regulate gene expression in a sequence-specific manner. Although miRNAs have been increasingly recognized as important modulators in sporadic AD. In order to confirm whether miR-15b correlates with the BACE1 upregulation in sporadic AD, we firstly evaluated the expression of miR-15b and BACE1 in sporadic AD brain tissues and analyzed the correlation of miR-15b with BACE1. Then we determined the regulation of miR-15b in SH-SY5Y cells on the BACE1 expression. And finally we determined the targeting to 3’ UTR of BACE1 by miR-15b by a luciferase reporter. Downregulation of miR-15b alleviated Aβ-induced viability inhibition and decreased apoptosis in SH-SY5Y cells. Our results demonstrated that miR-15b play an important role in the cellular AD phenotype and might be involved in the pathogenesis of AD.
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Affiliation(s)
- Guohua Gong
- Medicinal Chemistry and Pharmacology Institute, Inner Mongolia University for The Nationalities, Tongliao, Inner Mongolia, P.R. China.,Inner Mongolia Key Laboratory of Mongolian Medicine Pharmacology for Cardio-Cerebral Vascular System, Tongliao, Inner Mongolia, P.R. China.,First Clinical Medical of Inner Mongolia University for Nationalities, Tongliao, Inner Mongolia, P.R. China
| | - Fengmao An
- Medicinal Chemistry and Pharmacology Institute, Inner Mongolia University for The Nationalities, Tongliao, Inner Mongolia, P.R. China.,Inner Mongolia Key Laboratory of Mongolian Medicine Pharmacology for Cardio-Cerebral Vascular System, Tongliao, Inner Mongolia, P.R. China
| | - Yu Wang
- Medicinal Chemistry and Pharmacology Institute, Inner Mongolia University for The Nationalities, Tongliao, Inner Mongolia, P.R. China.,Inner Mongolia Key Laboratory of Mongolian Medicine Pharmacology for Cardio-Cerebral Vascular System, Tongliao, Inner Mongolia, P.R. China
| | - Ming Bian
- Medicinal Chemistry and Pharmacology Institute, Inner Mongolia University for The Nationalities, Tongliao, Inner Mongolia, P.R. China.,Inner Mongolia Key Laboratory of Mongolian Medicine Pharmacology for Cardio-Cerebral Vascular System, Tongliao, Inner Mongolia, P.R. China
| | - Li-Jun Yu
- Medicinal Chemistry and Pharmacology Institute, Inner Mongolia University for The Nationalities, Tongliao, Inner Mongolia, P.R. China.,Inner Mongolia Key Laboratory of Mongolian Medicine Pharmacology for Cardio-Cerebral Vascular System, Tongliao, Inner Mongolia, P.R. China
| | - Chengxi Wei
- Medicinal Chemistry and Pharmacology Institute, Inner Mongolia University for The Nationalities, Tongliao, Inner Mongolia, P.R. China.,Inner Mongolia Key Laboratory of Mongolian Medicine Pharmacology for Cardio-Cerebral Vascular System, Tongliao, Inner Mongolia, P.R. China
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14
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Copani A. The underexplored question of β-amyloid monomers. Eur J Pharmacol 2017; 817:71-75. [PMID: 28577967 DOI: 10.1016/j.ejphar.2017.05.057] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 05/12/2017] [Accepted: 05/30/2017] [Indexed: 01/03/2023]
Abstract
Conceived more than 25 years ago, the amyloid cascade hypothesis of Alzheimer's disease has evolved to accommodate new findings, namely different forms of β-amyloid aggregates and downstream dysfunctions. Yet, the cascade does not mention its very beginning, the β-amyloid monomer. Here, I will discuss the monomer from a functional evolutionary perspective, highlighting the potential advantages of a native unfolded state that, however, involves an amyloidogenic risk. Finally, I will make a summary of what is known about its functional role in the brain and discuss the implications of its conceivable shortage in the development of Alzheimer's disease.
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Affiliation(s)
- Agata Copani
- Department of Drug Sciences, University of Catania, Viale Andrea Doria 6, 95125 Catania, Italy.
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15
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Sato M. Early Origin and Evolution of the Angelman Syndrome Ubiquitin Ligase Gene Ube3a. Front Cell Neurosci 2017; 11:62. [PMID: 28326016 PMCID: PMC5339648 DOI: 10.3389/fncel.2017.00062] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 02/22/2017] [Indexed: 12/20/2022] Open
Abstract
The human Ube3a gene encodes an E3 ubiquitin ligase and exhibits brain-specific genomic imprinting. Genetic abnormalities that affect the maternal copy of this gene cause the neurodevelopmental disorder Angelman syndrome (AS), which is characterized by severe mental retardation, speech impairment, seizure, ataxia and some unique behavioral phenotypes. In this review article, I highlight the evolution of the Ube3a gene and its imprinting to provide evolutionary insights into AS. Recent comparative genomic studies have revealed that Ube3a is most phylogenetically similar to HECTD2 among the human HECT (homologous to the E6AP carboxyl terminus) family of E3 ubiquitin ligases, and its distant evolutionary origin can be traced to common ancestors of fungi and animals. Moreover, a gene more similar to Ube3a than HECTD2 is found in a range of eukaryotes from amoebozoans to basal metazoans, but is lost in later lineages. Unlike in mice and humans, Ube3a expression is biallelic in birds, monotremes, marsupials and insects. The imprinting domain that governs maternal expression of Ube3a was formed from non-imprinted elements following multiple chromosomal rearrangements after diversification of marsupials and placental mammals. Hence, the evolutionary origins of Ube3a date from long before the emergence of the nervous system, although its imprinted expression was acquired relatively recently. These observations suggest that exogenous expression and functional analyses of ancient Ube3a orthologs in mammalian neurons will facilitate the evolutionary understanding of AS.
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Affiliation(s)
- Masaaki Sato
- Graduate School of Science and Engineering and Brain and Body System Science Institute, Saitama UniversitySaitama, Japan
- RIKEN Brain Science InstituteWako, Japan
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16
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Salminen A, Kauppinen A, Kaarniranta K. Hypoxia/ischemia activate processing of Amyloid Precursor Protein: impact of vascular dysfunction in the pathogenesis of Alzheimer's disease. J Neurochem 2017; 140:536-549. [DOI: 10.1111/jnc.13932] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 12/05/2016] [Accepted: 12/10/2016] [Indexed: 12/13/2022]
Affiliation(s)
- Antero Salminen
- Department of Neurology; Institute of Clinical Medicine; University of Eastern Finland; Kuopio Finland
| | - Anu Kauppinen
- School of Pharmacy; Faculty of Health Sciences; University of Eastern Finland; Kuopio Finland
| | - Kai Kaarniranta
- Department of Ophthalmology; Institute of Clinical Medicine; University of Eastern Finland; Kuopio Finland
- Department of Ophthalmology; Kuopio University Hospital; Kuopio Finland
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17
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Li Q, Li X, Wang L, Zhang Y, Chen L. miR-98-5p Acts as a Target for Alzheimer's Disease by Regulating Aβ Production Through Modulating SNX6 Expression. J Mol Neurosci 2016; 60:413-420. [PMID: 27541017 DOI: 10.1007/s12031-016-0815-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 08/01/2016] [Indexed: 01/01/2023]
Abstract
Accumulation of amyloid β-peptide (Aβ) in the brain of Alzheimer disease (AD) patients is believed to be the main pathological feature of the disease. Meanwhile, miR-98-5p dysregulation was found in AD. However, whether miR-98-5p is involved in the accumulation of Aβ in AD, the underlying molecule mechanism remains unclear. In the present study, we confirmed that miR-98-5p negatively regulated sorting nexin 6 (SNX6) expression by targeting the 3'-UTR of SNX6 mRNA. Downregulation of miR-98-5p alleviated Aβ-induced viability inhibition and decreased apoptosis in SK-N-SH and SH-SY5Y cells by upregulating SNX6 expression. Furthermore, downregulation of miR-98-5p decreased SNX6-dependent levels of Aβ40, Aβ42, β-site APP-cleaving enzyme 1 (BACE1), soluble amyloid precursor protein β (sAPPβ), and membrane-associated APP β-carboxyl terminal fragment (βCTF) in SK-N-SH and HEK293 cells. Our findings demonstrate that miR-98-5p modulates SNX6 expression and thus plays a critical role in accumulation of Aβ. Therefore, miR-98-5p may be a novel therapeutic target for AD.
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Affiliation(s)
- Qiushi Li
- Department of Neurology, The First Affiliated Hospital of Jinzhou Medical University, Jinzhou, Liaoning, 121000, People's Republic of China
| | - Xidong Li
- Department of Neurology, The First Affiliated Hospital of Jinzhou Medical University, Jinzhou, Liaoning, 121000, People's Republic of China
| | - Li Wang
- Department of Neurology, Shenyang General Hospital of PLA, Shenyang, Liaoning, 110084, People's Republic of China
| | - Yanhui Zhang
- Department of Neurology, The First Affiliated Hospital of Jinzhou Medical University, Jinzhou, Liaoning, 121000, People's Republic of China
| | - Long Chen
- Department of Anesthesiology, The First Affiliated Hospital of Jinzhou Medical University, 5-2 People Street, Jinzhou, Liaoning, 121000, People's Republic of China.
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18
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Wang X, Yu X, Vaughan W, Liu M, Guan Y. Novel drug-delivery approaches to the blood-brain barrier. Neurosci Bull 2015; 31:257-64. [PMID: 25595370 DOI: 10.1007/s12264-014-1498-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 07/21/2014] [Indexed: 11/30/2022] Open
Abstract
The blood-brain barrier (BBB) maintains homeostasis by blocking toxic molecules from the circulation, but drugs are blocked at the same time. When the dose is increased to enhance the drug concentration in the central nervous system, there are side-effects on peripheral organs. In recent years, genetic therapeutic agents and small molecules have been used in various strategies to penetrate the BBB while minimizing the damage to systemic organs. In this review, we describe several representative methods to circumvent or cross the BBB, including chemical and physical strategies.
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Affiliation(s)
- Xiaoqing Wang
- Department of Neurology, Changhai Hospital, Second Military Medical University, Shanghai, 200433, China
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