1
|
Iram F, Shahid M, Ansari J, Ashraf GM, Hassan MI, Islam A. Navigating the Maze of Alzheimer's disease by exploring BACE1: Discovery, current scenario, and future prospects. Ageing Res Rev 2024; 98:102342. [PMID: 38762102 DOI: 10.1016/j.arr.2024.102342] [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: 03/07/2024] [Revised: 05/04/2024] [Accepted: 05/13/2024] [Indexed: 05/20/2024]
Abstract
Alzheimer's disease (AD) is a chronic neurological condition that has become a leading cause of cognitive decline in elder individuals. Hardly any effective medication has been developed to halt the progression of AD due to the disease's complexity. Several theories have been put forward to clarify the mechanisms underlying AD etiology. The identification of amyloid plaques as a hallmark of AD has sparked the development of numerous drugs targeting the players involved in the amyloidogenic pathway, such as the β-site of amyloid precursor protein cleavage enzyme 1 (BACE1) blockers. Over the last ten years, preclinical and early experimental research has led several pharmaceutical companies to prioritize producing BACE1 inhibitors. Despite all these efforts, earlier discovered inhibitors were discontinued in consideration of another second-generation small molecules and recent BACE1 antagonists failed in the final stages of clinical trials because of the complications associated either with toxicity or effectiveness. In addition to discussing the difficulties associated with development of BACE1 inhibitors, this review aims to provide an overview of BACE1 and offer perspectives on the causes behind the failure of five recent BACE1 inhibitors, that would be beneficial for choosing effective treatment approaches in the future.
Collapse
Affiliation(s)
- Faiza Iram
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India
| | - Mohammad Shahid
- Department of Basic Medical Sciences, College of Medicine, Prince Sattam Bin Abdulaziz University, Al-Kharj, Saudi Arabia
| | - Jaoud Ansari
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India
| | - Ghulam Md Ashraf
- University of Sharjah, College of Health Sciences, and Research Institute for Medical and Health Sciences, Department of Medical Laboratory Sciences, Sharjah 27272, United Arab Emirates
| | - Md Imtaiyaz Hassan
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India
| | - Asimul Islam
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India.
| |
Collapse
|
2
|
Liu SX, Villacis Calderon DG, Maxim ZL, Beeson MM, Rao R, Tran PV. Neonatal Hypoxia-Ischemia alters Brain-Derived Contactin-2-Positive Extracellular Vesicles in the Mouse Plasma. Neuroscience 2024; 545:141-147. [PMID: 38513760 DOI: 10.1016/j.neuroscience.2024.03.014] [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: 06/29/2023] [Revised: 03/06/2024] [Accepted: 03/16/2024] [Indexed: 03/23/2024]
Abstract
Neonatal encephalopathy (NE) impairs white matter development and results in long-term neurodevelopmental deficits. Leveraging prior findings of altered neuronal proteins carried by brain-derived extracellular vesicles (EVs) that are marked by a neural-specific cell surface glycoprotein Contactin-2 (CNTN2) in NE infants, the present study aimed to determine the correlation between brain and circulating CNTN2+-EVs and whether NE alters circulating CNTN2+-EV levels in mice. Brain tissue and plasma were collected from postnatal day (P)7, 10, 11, 15 mice to determine the baseline CNTN2 correlation between these two compartments (n = 4-7/time point/sex). NE was induced in P10 pups. Brain and plasma samples were collected at 1, 3, 6, 24, and 120 h (n = 4-8/time point/sex). CNTN2 from brain tissue and plasma EVs were quantified using ELISA. ANOVA and linear regression analyses were used to evaluate changes and correlations between brain and plasma CNTN2+-EVs. In baseline experiments, CNTN2 in brain tissue and plasma EVs peaked at P10 with no sex-difference. Brain and plasma CNTN2+-EV showed a positive correlation across early postnatal ages. NE pups showed an elevated CNTN2 in brain tissue and EVs at 1 h and only in brain tissue at 24 h. NE also abolished the positive plasma-brain correlation. The findings establish a link for central CNTN2 and its release into circulation during early postnatal life. The immediate elevation and release of CNTN2 following NE highlight a potential molecular response shortly after a brain injurious event. Our findings further support the utility of circulating brain-derived EVs as a possible bioindicator of NE.
Collapse
Affiliation(s)
- Shirelle X Liu
- Department of Pediatrics, University of Minnesota, Minneapolis, MN, USA
| | | | - Zia L Maxim
- Department of Pediatrics, University of Minnesota, Minneapolis, MN, USA
| | - Montana M Beeson
- Department of Pediatrics, University of Minnesota, Minneapolis, MN, USA
| | - Raghavendra Rao
- Department of Pediatrics, University of Minnesota, Minneapolis, MN, USA
| | - Phu V Tran
- Department of Pediatrics, University of Minnesota, Minneapolis, MN, USA.
| |
Collapse
|
3
|
Chataigner LMP, Thärichen L, Beugelink JW, Granneman JCM, Mokiem NJ, Snijder J, Förster F, Janssen BJC. Contactin 2 homophilic adhesion structure and conformational plasticity. Structure 2024; 32:60-73.e5. [PMID: 37992710 DOI: 10.1016/j.str.2023.10.012] [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: 06/21/2022] [Revised: 09/27/2023] [Accepted: 10/26/2023] [Indexed: 11/24/2023]
Abstract
The cell-surface attached glycoprotein contactin 2 is ubiquitously expressed in the nervous system and mediates homotypic cell-cell interactions to organize cell guidance, differentiation, and adhesion. Contactin 2 consists of six Ig and four fibronectin type III domains (FnIII) of which the first four Ig domains form a horseshoe structure important for homodimerization and oligomerization. Here we report the crystal structure of the six-domain contactin 2Ig1-6 and show that the Ig5-Ig6 combination is oriented away from the horseshoe with flexion in interdomain connections. Two distinct dimer states, through Ig1-Ig2 and Ig3-Ig6 interactions, together allow formation of larger oligomers. Combined size exclusion chromatography with multiangle light scattering (SEC-MALS), small-angle X-ray scattering (SAXS) and native MS analysis indicates contactin 2Ig1-6 oligomerizes in a glycan dependent manner. SAXS and negative-stain electron microscopy reveals inherent plasticity of the contactin 2 full-ectodomain. The combination of intermolecular binding sites and ectodomain plasticity explains how contactin 2 can function as a homotypic adhesion molecule in diverse intercellular environments.
Collapse
Affiliation(s)
- Lucas M P Chataigner
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Faculty of Science, Utrecht University, Universiteitsweg 99, Utrecht 3584 CG, the Netherlands
| | - Lena Thärichen
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Faculty of Science, Utrecht University, Universiteitsweg 99, Utrecht 3584 CG, the Netherlands
| | - J Wouter Beugelink
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Faculty of Science, Utrecht University, Universiteitsweg 99, Utrecht 3584 CG, the Netherlands
| | - Joke C M Granneman
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Faculty of Science, Utrecht University, Universiteitsweg 99, Utrecht 3584 CG, the Netherlands
| | - Nadia J Mokiem
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute of Pharmaceutical Sciences, Utrecht University, Padualaan 8, Utrecht 3584 CH, the Netherlands
| | - Joost Snijder
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute of Pharmaceutical Sciences, Utrecht University, Padualaan 8, Utrecht 3584 CH, the Netherlands
| | - Friedrich Förster
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Faculty of Science, Utrecht University, Universiteitsweg 99, Utrecht 3584 CG, the Netherlands
| | - Bert J C Janssen
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Faculty of Science, Utrecht University, Universiteitsweg 99, Utrecht 3584 CG, the Netherlands.
| |
Collapse
|
4
|
Rochín-Hernández LJ, Jiménez-Acosta MA, Ramírez-Reyes L, Figueroa-Corona MDP, Sánchez-González VJ, Orozco-Barajas M, Meraz-Ríos MA. The Proteome Profile of Olfactory Ecto-Mesenchymal Stem Cells-Derived from Patients with Familial Alzheimer's Disease Reveals New Insights for AD Study. Int J Mol Sci 2023; 24:12606. [PMID: 37628788 PMCID: PMC10454072 DOI: 10.3390/ijms241612606] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 08/01/2023] [Accepted: 08/04/2023] [Indexed: 08/27/2023] Open
Abstract
Alzheimer's disease (AD), the most common neurodegenerative disease and the first cause of dementia worldwide, has no effective treatment, and its pathological mechanisms are not yet fully understood. We conducted this study to explore the proteomic differences associated with Familial Alzheimer's Disease (FAD) in olfactory ecto-mesenchymal stem cells (MSCs) derived from PSEN1 (A431E) mutation carriers compared with healthy donors paired by age and gender through two label-free liquid chromatography-mass spectrometry approaches. The first analysis compared carrier 1 (patient with symptoms, P1) and its control (healthy donor, C1), and the second compared carrier 2 (patient with pre-symptoms, P2) with its respective control cells (C2) to evaluate whether the protein alterations presented in the symptomatic carrier were also present in the pre-symptom stages. Finally, we analyzed the differentially expressed proteins (DEPs) for biological and functional enrichment. These proteins showed impaired expression in a stage-dependent manner and are involved in energy metabolism, vesicle transport, actin cytoskeleton, cell proliferation, and proteostasis pathways, in line with previous AD reports. Our study is the first to conduct a proteomic analysis of MSCs from the Jalisco FAD patients in two stages of the disease (symptomatic and presymptomatic), showing these cells as a new and excellent in vitro model for future AD studies.
Collapse
Affiliation(s)
- Lory J. Rochín-Hernández
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Instituto Politécnico Nacional 2508, Ciudad de México 07360, Mexico; (L.J.R.-H.); (M.A.J.-A.); (M.d.P.F.-C.)
| | - Miguel A. Jiménez-Acosta
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Instituto Politécnico Nacional 2508, Ciudad de México 07360, Mexico; (L.J.R.-H.); (M.A.J.-A.); (M.d.P.F.-C.)
| | - Lorena Ramírez-Reyes
- Unidad de Genómica, Proteómica y Metabolómica, Laboratorio Nacional de Servicios Experimentales (LaNSE), Centro de Investigación y de Estudios Avanzados, Ciudad de México 07360, Mexico;
| | - María del Pilar Figueroa-Corona
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Instituto Politécnico Nacional 2508, Ciudad de México 07360, Mexico; (L.J.R.-H.); (M.A.J.-A.); (M.d.P.F.-C.)
| | - Víctor J. Sánchez-González
- Centro Universitario de Los Altos, Universidad de Guadalajara, Tepatitlán de Morelos 47620, Mexico; (V.J.S.-G.); (M.O.-B.)
| | - Maribel Orozco-Barajas
- Centro Universitario de Los Altos, Universidad de Guadalajara, Tepatitlán de Morelos 47620, Mexico; (V.J.S.-G.); (M.O.-B.)
| | - Marco A. Meraz-Ríos
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Instituto Politécnico Nacional 2508, Ciudad de México 07360, Mexico; (L.J.R.-H.); (M.A.J.-A.); (M.d.P.F.-C.)
| |
Collapse
|
5
|
Meng N, Pan P, Hu S, Miao C, Hu Y, Wang F, Zhang J, An L. The molecular mechanism of γ-aminobutyric acid against AD: the role of CEBPα/circAPLP2/miR-671-5p in regulating CNTN1/2 expression. Food Funct 2023; 14:2082-2095. [PMID: 36734072 DOI: 10.1039/d2fo03049g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The expression levels of the synaptic-related proteins contactin 1/2 (CNTN1/2) are down-regulated in the brain of Alzheimer's disease (AD), but the mechanism has not been clarified. γ-Aminobutyric acid (GABA) is considered a biologically active ingredient in food. Our previous research revealed that GABA can regulate CEBPα expression in Aβ-treated U251 cells. However, it is uncertain whether GABA can antagonize the pathogenesis of AD. Whether GABA can inhibit the reduction in CNTN1/2 expression by regulating CEBPα/circAPLP2/miR-671-5p in the AD brain remains unclear yet. Here, we demonstrate that GABA could attenuate the deposition of Aβ in the brain and ameliorate cognitive impairments in AD model mice. The expressions of CEBPα, circAPLP2, and CNTN1/2 were decreased and that of miR-671-5p was increased in AD model mouse brains and Aβ-induced SH-SY5Y cells. These alterations were partly reversed by GABA. The CNTN1/2 expression was down-regulated and up-regulated in SH-SY5Y cells treated with miR-671-5p mimics and miR-671-5p inhibitors, respectively. The results from the luciferase reporter assay revealed that miR-671-5p could bind to the 3'-untranslated region of circAPLP2. The silencing of circAPLP2 with the siRNA duplex caused an up-regulation of miR-671-5p and a down-regulation of CNTN1/2 in SH-SY5Y cells. The silencing of CEBPα with the siRNA duplex caused a down-regulation of circAPLP2 or CNTN1/2 and an up-regulation of miR-671-5p. In conclusion, GABA may decrease the deposition of Aβ in the brain, inhibit the down-regulation of CNTN1/2 expression, and ameliorate the cognitive deficits of AD model mice. The CEBPα/circAPLP2/miR-671-5p pathway plays a role in regulating CNTN1/2 expression by GABA in AD.
Collapse
Affiliation(s)
- Na Meng
- Department of Nutrition and Food Hygiene, School of Public Health, China Medical University, Shenyang, China.
| | - Pengyu Pan
- Department of Nutrition and Food Hygiene, School of Public Health, China Medical University, Shenyang, China.
| | - Shuang Hu
- Department of Nutrition and Food Hygiene, School of Public Health, China Medical University, Shenyang, China.
| | - Chen Miao
- Department of Nutrition and Food Hygiene, School of Public Health, China Medical University, Shenyang, China.
| | - Yixin Hu
- Department of Nutrition and Food Hygiene, School of Public Health, China Medical University, Shenyang, China.
| | - Fangfang Wang
- Department of Nutrition and Food Hygiene, School of Public Health, China Medical University, Shenyang, China.
| | - Jingzhu Zhang
- Department of Nutrition and Food Hygiene, School of Public Health, China Medical University, Shenyang, China.
| | - Li An
- Department of Nutrition and Food Hygiene, School of Public Health, China Medical University, Shenyang, China.
| |
Collapse
|
6
|
Saunders TS, Gadd DA, Spires‐Jones TL, King D, Ritchie C, Muniz‐Terrera G. Associations between cerebrospinal fluid markers and cognition in ageing and dementia: A systematic review. Eur J Neurosci 2022; 56:5650-5713. [PMID: 35338546 PMCID: PMC9790745 DOI: 10.1111/ejn.15656] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 03/08/2022] [Accepted: 03/13/2022] [Indexed: 12/30/2022]
Abstract
A biomarker associated with cognition in neurodegenerative dementias would aid in the early detection of disease progression, complement clinical staging and act as a surrogate endpoint in clinical trials. The current systematic review evaluates the association between cerebrospinal fluid protein markers of synapse loss and neuronal injury and cognition. We performed a systematic search which revealed 67 studies reporting an association between cerebrospinal fluid markers of interest and neuropsychological performance. Despite the substantial heterogeneity between studies, we found some evidence for an association between neurofilament-light and worse cognition in Alzheimer's diseases, frontotemporal dementia and typical cognitive ageing. Moreover, there was an association between cerebrospinal fluid neurogranin and cognition in those with an Alzheimer's-like cerebrospinal fluid biomarker profile. Some evidence was found for cerebrospinal fluid neuronal pentraxin-2 as a correlate of cognition across dementia syndromes. Due to the substantial heterogeneity of the field, no firm conclusions can be drawn from this review. Future research should focus on improving standardization and reporting as well as establishing the importance of novel markers such as neuronal pentraxin-2 and whether such markers can predict longitudinal cognitive decline.
Collapse
Affiliation(s)
- Tyler S. Saunders
- UK Dementia Research InstituteThe University of EdinburghEdinburghUK,Center for Discovery Brain SciencesThe University of EdinburghEdinburghUK,Center for Clinical Brain SciencesThe University of EdinburghEdinburghUK,Center for Dementia PreventionThe University of EdinburghEdinburghUK
| | - Danni A. Gadd
- Center for Genomic and Experimental Medicine, Institute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUK
| | - Tara L. Spires‐Jones
- UK Dementia Research InstituteThe University of EdinburghEdinburghUK,Center for Discovery Brain SciencesThe University of EdinburghEdinburghUK
| | - Declan King
- UK Dementia Research InstituteThe University of EdinburghEdinburghUK,Center for Discovery Brain SciencesThe University of EdinburghEdinburghUK
| | - Craig Ritchie
- Center for Clinical Brain SciencesThe University of EdinburghEdinburghUK,Center for Dementia PreventionThe University of EdinburghEdinburghUK
| | - Graciela Muniz‐Terrera
- Center for Clinical Brain SciencesThe University of EdinburghEdinburghUK,Center for Dementia PreventionThe University of EdinburghEdinburghUK
| |
Collapse
|
7
|
Guanidine-based β amyloid precursor protein cleavage enzyme 1 (BACE-1) inhibitors for the Alzheimer's disease (AD): A review. Bioorg Med Chem 2022; 74:117047. [DOI: 10.1016/j.bmc.2022.117047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 09/16/2022] [Accepted: 10/04/2022] [Indexed: 11/02/2022]
|
8
|
Finding New Ways How to Control BACE1. J Membr Biol 2022; 255:293-318. [PMID: 35305135 DOI: 10.1007/s00232-022-00225-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 02/24/2022] [Indexed: 01/18/2023]
Abstract
Recently, all applications of BACE1 inhibitors failed as therapeutical targets for Alzheimer´s disease (AD) due to severe side effects. Therefore, alternative ways for treatment development are a hot research topic. The present analysis investigates BACE1 protein-protein interaction networks and attempts to solve the absence of complete knowledge about pathways involving BACE1. A bioinformatics analysis matched the functions of the non-substrate interaction network with Voltage-gated potassium channels, which also appear as top priority protein nodes. Targeting BACE1 interactions with PS1 and GGA-s, blocking of BACE1 access to APP by BRI3 and RTN-s, activation of Wnt signaling and upregulation of β-catenin, and brain delivery of the extracellular domain of p75NTR, are the main alternatives to the use of BACE 1 inhibitors highlighted by the analysis. The pathway enrichment analysis also emphasized substrates and substrate candidates with essential biological functions, which cleavage must remain controlled. They include ephrin receptors, ROBO1, ROBO2, CNTN-s, CASPR-s, CD147, CypB, TTR, APLP1/APLP2, NRXN-s, and PTPR-s. The analysis of the interaction subnetwork of BACE1 functionally related to inflammation identified a connection to three cardiomyopathies, which supports the hypothesis of the common molecular mechanisms with AD. A lot of potential shows the regulation of BACE1 activity through post-translational modifications. The interaction network of BACE1 and its phosphorylation enzyme CSNK1D functionally match the Circadian clock, p53, and Hedgehog signaling pathways. The regulation of BACE1 glycosylation could be achieved through N-acetylglucosamine transferases, α-(1→6)-fucosyltransferase, β-galactoside α-(2→6)-sialyltransferases, galactosyltransferases, and mannosidases suggested by the interaction network analysis of BACE1-MGAT3. The present analysis proposes possibilities for the alternative control of AD pathology.
Collapse
|
9
|
Kalafatakis I, Kalafatakis K, Tsimpolis A, Giannakeas N, Tsipouras M, Tzallas A, Karagogeos D. Using the Allen gene expression atlas of the adult mouse brain to gain further insight into the physiological significance of TAG-1/Contactin-2. Brain Struct Funct 2020; 225:2045-2056. [PMID: 32601750 DOI: 10.1007/s00429-020-02108-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Accepted: 06/21/2020] [Indexed: 12/11/2022]
Abstract
The anatomic gene expression atlas (AGEA) of the adult mouse brain of the Allen Institute for Brain Science is a transcriptome-based atlas of the adult C57Bl/6 J mouse brain, based on the extensive in situ hybridization dataset of the Institute. This spatial mapping of the gene expression levels of mice under baseline conditions could assist in the formation of new, reasonable transcriptome-derived hypotheses on brain structure and underlying biochemistry, which could also have functional implications. The aim of this work is to use the data of the AGEA (in combination with Tabula Muris, a compendium of single cell transcriptome data collected from mice, enabling direct and controlled comparison of gene expression among cell types) to provide further insights into the physiology of TAG-1/Contactin-2 and its interactions, by presenting the expression of the corresponding gene across the adult mouse brain under baseline conditions and to investigate any spatial genomic correlations between TAG-1/Contactin-2 and its interacting proteins and markers of mature and immature oligodendrocytes, based on the pre-existing experimental or bibliographical evidence. The across-brain correlation analysis on the gene expression intensities showed a positive spatial correlation of TAG-1/Contactin-2 with the gene expression of Plp1, Myrf, Mbp, Mog, Cldn11, Bace1, Kcna1, Kcna2, App and Nfasc and a negative spatial correlation with the gene expression of Cspg4, Pdgfra, L1cam, Ncam1, Ncam2 and Ptprz1. Spatially correlated genes are mainly expressed by mature oligodendrocytes (like Cntn2), while spatially anticorrelated genes are mainly expressed by oligodendrocyte precursor cells. According to the data presented in this work, we propose that even though Contactin-2 expression during development correlates with high plasticity events, such as neuritogenesis, in adulthood it correlates with pathways characterized by low plasticity.
Collapse
Affiliation(s)
- Ilias Kalafatakis
- Faculty of Medicine, University of Crete & Institute of Molecular Biology and Biotechnology, Foundation of Research and Technology Hellas, Heraklion, Crete, Greece.
| | - Konstantinos Kalafatakis
- Faculty of Medicine, University of Crete & Institute of Molecular Biology and Biotechnology, Foundation of Research and Technology Hellas, Heraklion, Crete, Greece
- Department of Informatics and Telecommunications, School of Informatics and Telecommunications, University of Ioannina, Arta, Greece
| | - Alexandros Tsimpolis
- Faculty of Medicine, University of Crete & Institute of Molecular Biology and Biotechnology, Foundation of Research and Technology Hellas, Heraklion, Crete, Greece
| | - Nikos Giannakeas
- Department of Informatics and Telecommunications, School of Informatics and Telecommunications, University of Ioannina, Arta, Greece
| | - Markos Tsipouras
- Department of Informatics and Telecommunications, School of Informatics and Telecommunications, University of Ioannina, Arta, Greece
| | - Alexandros Tzallas
- Department of Informatics and Telecommunications, School of Informatics and Telecommunications, University of Ioannina, Arta, Greece
| | - Domna Karagogeos
- Faculty of Medicine, University of Crete & Institute of Molecular Biology and Biotechnology, Foundation of Research and Technology Hellas, Heraklion, Crete, Greece
| |
Collapse
|
10
|
Chatterjee M, Teunissen C. Contactins & Alzheimer's Disease: Synaptic Proteins, Contactins may Contribute to the Pathology of Alzheimer's Disease. Neuroscience 2020; 424:182-183. [PMID: 31682946 DOI: 10.1016/j.neuroscience.2019.10.042] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 10/23/2019] [Accepted: 10/24/2019] [Indexed: 01/06/2023]
Affiliation(s)
- Madhurima Chatterjee
- Amsterdam UMC, VU University Medical Center, Department of Clinical Chemistry, Amsterdam Neuroscience, Amsterdam, the Netherlands
| | - Charlotte Teunissen
- Amsterdam UMC, VU University Medical Center, Department of Clinical Chemistry, Amsterdam Neuroscience, Amsterdam, the Netherlands.
| |
Collapse
|
11
|
The Interaction Between Contactin and Amyloid Precursor Protein and Its Role in Alzheimer’s Disease. Neuroscience 2020; 424:184-202. [DOI: 10.1016/j.neuroscience.2019.10.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 10/01/2019] [Accepted: 10/03/2019] [Indexed: 01/06/2023]
|
12
|
Cord Blood-Derived Exosomal CNTN2 and BDNF: Potential Molecular Markers for Brain Health of Neonates at Risk for Iron Deficiency. Nutrients 2019; 11:nu11102478. [PMID: 31623079 PMCID: PMC6835945 DOI: 10.3390/nu11102478] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 10/10/2019] [Accepted: 10/14/2019] [Indexed: 01/18/2023] Open
Abstract
Maternal iron deficiency anemia, obesity, and diabetes are prevalent during pregnancy. All are associated with neonatal brain iron deficiency (ID) and neurodevelopmental impairment. Exosomes are extracellular vesicles involved in cell–cell communication. Contactin-2 (CNTN2), a neural-specific glycoprotein, and brain-derived neurotrophic factor (BDNF) are important in neurodevelopment and found in exosomes. We hypothesized that exosomal CNTN2 and BDNF identify infants at risk for brain ID. Umbilical cord blood samples were measured for iron status. Maternal anemia, diabetes, and body mass index (BMI) were recorded. Cord blood exosomes were isolated and validated for the exosomal marker CD81 and the neural-specific exosomal marker CNTN2. Exosomal CNTN2 and BDNF levels were quantified by ELISA. Analysis of CNTN2 and BDNF levels as predictors of cord blood iron indices showed a direct correlation between CNTN2 and ferritin in all neonates (n = 79, β = 1.75, p = 0.02). In contrast, BDNF levels inversely correlated with ferritin (β = −1.20, p = 0.03), with stronger association in female neonates (n = 37, β = −1.35, p = 0.06), although there is no evidence of a sex-specific effect. Analysis of maternal risk factors for neonatal brain ID as predictors of exosomal CNTN2 and BDNF levels showed sex-specific relationships between infants of diabetic mothers (IDMs) and CNTN2 levels (Interaction p = 0.0005). While male IDMs exhibited a negative correlation (n = 42, β = −0.69, p = 0.02), female IDMs showed a positive correlation (n = 37, β = 0.92, p = 0.01) with CNTN2. A negative correlation between BNDF and maternal BMI was found with stronger association in female neonates (per 10 units BMI, β = −0.60, p = 0.04). These findings suggest CNTN2 and BNDF are respective molecular markers for male and female neonates at risk for brain ID. This study supports the potential of exosomal markers to assess neonatal brain status in at-risk infants.
Collapse
|
13
|
β-Secretase BACE1 Is Required for Normal Cochlear Function. J Neurosci 2019; 39:9013-9027. [PMID: 31527119 DOI: 10.1523/jneurosci.0028-19.2019] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 08/30/2019] [Accepted: 09/04/2019] [Indexed: 12/20/2022] Open
Abstract
Cleavage of amyloid precursor protein (APP) by β-secretase BACE1 initiates the production and accumulation of neurotoxic amyloid-β peptides, which is widely considered an essential pathogenic mechanism in Alzheimer's disease (AD). Here, we report that BACE1 is essential for normal auditory function. Compared with wild-type littermates, BACE1-/- mice of either sex exhibit significant hearing deficits, as indicated by increased thresholds and reduced amplitudes in auditory brainstem responses (ABRs) and decreased distortion product otoacoustic emissions (DPOAEs). Immunohistochemistry revealed aberrant synaptic organization in the cochlea and hypomyelination of auditory nerve fibers as predominant neuropathological substrates of hearing loss in BACE1-/- mice. In particular, we found that fibers of spiral ganglion neurons (SGN) close to the organ of Corti are disorganized and abnormally swollen. BACE1 deficiency also engenders organization defects in the postsynaptic compartment of SGN fibers with ectopic overexpression of PSD95 far outside the synaptic region. During postnatal development, auditory fiber myelination in BACE1-/- mice lags behind dramatically and remains incomplete into adulthood. We relate the marked hypomyelination to the impaired processing of Neuregulin-1 when BACE1 is absent. To determine whether the cochlea of adult wild-type mice is susceptible to AD treatment-like suppression of BACE1, we administered the established BACE1 inhibitor NB-360 for 6 weeks. The drug suppressed BACE1 activity in the brain, but did not impair hearing performance and, upon neuropathological examination, did not produce the characteristic cochlear abnormalities of BACE1-/- mice. Together, these data strongly suggest that the hearing loss of BACE1 knock-out mice represents a developmental phenotype.SIGNIFICANCE STATEMENT Given its crucial role in the pathogenesis of Alzheimer's disease (AD), BACE1 is a prime pharmacological target for AD prevention and therapy. However, the safe and long-term administration of BACE1-inhibitors as envisioned in AD requires a comprehensive understanding of the various physiological functions of BACE1. Here, we report that BACE1 is essential for the processing of auditory signals in the inner ear, as BACE1-deficient mice exhibit significant hearing loss. We relate this deficit to impaired myelination and aberrant synapse formation in the cochlea, which manifest during postnatal development. By contrast, prolonged pharmacological suppression of BACE1 activity in adult wild-type mice did not reproduce the hearing deficit or the cochlear abnormalities of BACE1 null mice.
Collapse
|
14
|
High-throughput epitope profiling of antibodies in the plasma of Alzheimer's disease patients using random peptide microarrays. Sci Rep 2019; 9:4587. [PMID: 30872784 PMCID: PMC6418098 DOI: 10.1038/s41598-019-40976-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 02/26/2019] [Indexed: 12/27/2022] Open
Abstract
The symptoms of Alzheimer's disease (AD), a major cause of dementia in older adults, are linked directly with neuronal cell death, which is thought to be due to aberrant neuronal inflammation. Autoantibodies formed during neuronal inflammation show excellent stability in blood; therefore, they may be convenient blood-based diagnostic markers of AD. Here, we performed microarray analysis of 29,240 unbiased random peptides to be used for comprehensive screening of AD-specific IgG and IgM antibodies in the blood. The results showed that (1) sequence-specific and isotype-specific antibodies are regulated differentially in AD, and combinations of these antibodies showing high area under the receiver operating characteristic curve values (0.862-0.961) can be used to classify AD, (2) AD-specific IgG antibodies arise from IgM antibody-secreting cells that existed before disease onset and (3) target protein profiling of the antibodies identified some AD-related proteins, some of which are involved in AD-related signalling pathways. Therefore, we propose that these epitopes may facilitate the development of biomarkers for AD diagnosis and form the basis for a mechanistic study related to AD progression.
Collapse
|
15
|
Abstract
Alzheimer's disease (AD), the most common cause of age-dependent dementia, is one of the most significant healthcare problems worldwide. Aggravating this situation, drugs that are currently US Food and Drug Administration (FDA)-approved for AD treatment do not prevent or delay disease progression. Therefore, developing effective therapies for AD patients is of critical urgency. Human genetic and clinical studies over the past three decades have indicated that abnormal generation or accumulation of amyloid-β (Aβ) peptides is a likely culprit in AD pathogenesis. Aβ is generated from amyloid precursor protein (APP) via proteolytic cleavage by β-site APP cleaving enzyme 1 (BACE1) (memapsin 2, β-secretase, Asp 2 protease) and γ-secretase. Mice deficient in BACE1 show abrogated production of Aβ. Therefore, pharmacological inhibition of BACE1 is being intensively pursued as a therapeutic approach to treat AD patients. Recent setbacks in clinical trials with BACE1 inhibitors have highlighted the critical importance of understanding how to properly inhibit BACE1 to treat AD patients. This review summarizes the recent studies on the role of BACE1 in synaptic functions as well as our views on BACE1 inhibition as an effective AD treatment.
Collapse
Affiliation(s)
- Brati Das
- Department of Neuroscience, Room E4032, UConn Health, 263 Farmington Avenue, Farmington, CT, 06030-3401, USA
| | - Riqiang Yan
- Department of Neuroscience, Room E4032, UConn Health, 263 Farmington Avenue, Farmington, CT, 06030-3401, USA.
| |
Collapse
|
16
|
Petri J, Syed MH, Rey S, Klämbt C. Non-Cell-Autonomous Function of the GPI-Anchored Protein Undicht during Septate Junction Assembly. Cell Rep 2019; 26:1641-1653.e4. [DOI: 10.1016/j.celrep.2019.01.046] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 12/12/2018] [Accepted: 01/10/2019] [Indexed: 11/26/2022] Open
|
17
|
Chatterjee M, Schild D, Teunissen CE. Contactins in the central nervous system: role in health and disease. Neural Regen Res 2019; 14:206-216. [PMID: 30530999 PMCID: PMC6301169 DOI: 10.4103/1673-5374.244776] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 09/17/2018] [Indexed: 01/06/2023] Open
Abstract
Contactins are a group of cell adhesion molecules that are mainly expressed in the brain and play pivotal roles in the organization of axonal domains, axonal guidance, neuritogenesis, neuronal development, synapse formation and plasticity, axo-glia interactions and neural regeneration. Contactins comprise a family of six members. Their absence leads to malformed axons and impaired nerve conduction. Contactin mediated protein complex formation is critical for the organization of the axon in early central nervous system development. Mutations and differential expression of contactins have been identified in neuro-developmental or neurological disorders. Taken together, contactins are extensively studied in the context of nervous system development. This review summarizes the physiological roles of all six members of the Contactin family in neurodevelopment as well as their involvement in neurological/neurodevelopmental disorders.
Collapse
Affiliation(s)
- Madhurima Chatterjee
- Amsterdam UMC, VU University Medical Center, Department of Clinical Chemistry, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Detlev Schild
- Institute of Neurophysiology and Cellular Biophysics, University of Göttingen, Göttingen, Germany
- DFG Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), University of Göttingen, Göttingen, Germany
- DFG Excellence Cluster 171, University of Göttingen, Göttingen, Germany
| | - Charlotte E. Teunissen
- Amsterdam UMC, VU University Medical Center, Department of Clinical Chemistry, Amsterdam Neuroscience, Amsterdam, The Netherlands
| |
Collapse
|
18
|
Consequences of Pharmacological BACE Inhibition on Synaptic Structure and Function. Biol Psychiatry 2018; 84:478-487. [PMID: 29945719 DOI: 10.1016/j.biopsych.2018.04.022] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 04/28/2018] [Accepted: 04/28/2018] [Indexed: 12/17/2022]
Abstract
Alzheimer's disease is the most prevalent neurodegenerative disorder among elderly persons. Overt accumulation and aggregation of the amyloid-β peptide (Aβ) is thought to be the initial causative factor for Alzheimer's disease. Aβ is produced by sequential proteolytic cleavage of the amyloid precursor protein. Beta-site amyloid precursor protein cleaving enzyme 1 (BACE1) is the initial and rate-limiting protease for the generation of Aβ. Therefore, inhibiting BACE1 is considered one of the most promising therapeutic approaches for potential treatment of Alzheimer's disease. Currently, several drugs blocking this enzyme (BACE inhibitors) are being evaluated in clinical trials. However, high-dosage BACE-inhibitor treatment interferes with structural and functional synaptic plasticity in mice. These adverse side effects may mask the therapeutic benefit of lowering the Aβ concentration. In this review, we focus on the consequences of BACE inhibition-mediated synaptic deficits and the potential clinical implications.
Collapse
|
19
|
Contactin-2, a synaptic and axonal protein, is reduced in cerebrospinal fluid and brain tissue in Alzheimer's disease. ALZHEIMERS RESEARCH & THERAPY 2018; 10:52. [PMID: 29859129 PMCID: PMC5984818 DOI: 10.1186/s13195-018-0383-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 05/09/2018] [Indexed: 11/23/2022]
Abstract
Background Synaptic and axonal loss are two major mechanisms underlying Alzheimer’s disease (AD) pathogenesis, and biomarkers reflecting changes in these cellular processes are needed for early diagnosis and monitoring the progression of AD. Contactin-2 is a synaptic and axonal membrane protein that interacts with proteins involved in the pathology of AD such as amyloid precursor protein (APP) and beta-secretase 1 (BACE1). We hypothesized that AD might be characterized by changes in contactin-2 levels in the cerebrospinal fluid (CSF) and brain tissue. Therefore, we aimed to investigate the levels of contactin-2 in the CSF and evaluate its relationship with disease pathology. Methods Contactin-2 was measured in CSF from two cohorts (selected from the Amsterdam Dementia Cohort), comprising samples from controls (cohort 1, n = 28; cohort 2, n = 20) and AD (cohort 1, n = 36; cohort 2, n = 70) using an analytically validated commercial enzyme-linked immunosorbent assay (ELISA). The relationship of contactin-2 with cognitive decline (Mini-Mental State Examination (MMSE)) and other CSF biomarkers reflecting AD pathology were analyzed. We further characterized the expression of contactin-2 in postmortem AD human brain (n = 14) versus nondemented controls (n = 9). Results CSF contactin-2 was approximately 1.3-fold reduced in AD patients compared with controls (p < 0.0001). Overall, contactin-2 levels correlated with MMSE scores (r = 0.35, p = 0.004). We observed that CSF contactin-2 correlated with the levels of phosphorylated tau within the control (r = 0.46, p < 0.05) and AD groups (r = 0.31, p < 0.05). Contactin-2 also correlated strongly with another synaptic biomarker, neurogranin (control: r = 0.62, p < 0.05; AD: r = 0.60, p < 0.01), and BACE1, a contactin-2 processing enzyme (control: r = 0.64, p < 0.01; AD: r = 0.46, p < 0.05). Results were further validated in a second cohort (p < 0.01). Immunohistochemical analysis revealed that contactin-2 is expressed in the extracellular matrix. Lower levels of contactin-2 were specifically found in and around amyloid plaques in AD hippocampus and temporal cortex. Conclusions Taken together, these data reveal that the contactin-2 changes observed in tissues are reflected in CSF, suggesting that decreased contactin-2 CSF levels might be a biomarker reflecting synaptic or axonal loss. Electronic supplementary material The online version of this article (10.1186/s13195-018-0383-x) contains supplementary material, which is available to authorized users.
Collapse
|
20
|
Herber J, Njavro J, Feederle R, Schepers U, Müller UC, Bräse S, Müller SA, Lichtenthaler SF. Click Chemistry-mediated Biotinylation Reveals a Function for the Protease BACE1 in Modulating the Neuronal Surface Glycoproteome. Mol Cell Proteomics 2018; 17:1487-1501. [PMID: 29716987 DOI: 10.1074/mcp.ra118.000608] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 04/16/2018] [Indexed: 01/09/2023] Open
Abstract
The cell surface proteome is dynamic and has fundamental roles in cell signaling. Many surface membrane proteins are proteolytically released into a cell's secretome, where they can have additional functions in cell-cell-communication. Yet, it remains challenging to determine the surface proteome and to compare it to the cell secretome, under serum-containing cell culture conditions. Here, we set up and evaluated the 'surface-spanning protein enrichment with click sugars' (SUSPECS) method for cell surface membrane glycoprotein biotinylation, enrichment and label-free quantitative mass spectrometry. SUSPECS is based on click chemistry-mediated labeling of glycoproteins, is compatible with labeling of living cells and can be combined with secretome analyses in the same experiment. Immunofluorescence-based confocal microscopy demonstrated that SUSPECS selectively labeled cell surface proteins. Nearly 700 transmembrane glycoproteins were consistently identified at the surface of primary neurons. To demonstrate the utility of SUSPECS, we applied it to the protease BACE1, which is a key drug target in Alzheimer's disease. Pharmacological BACE1-inhibition selectively remodeled the neuronal surface glycoproteome, resulting in up to 7-fold increased abundance of the BACE1 substrates APP, APLP1, SEZ6, SEZ6L, CNTN2, and CHL1, whereas other substrates were not or only mildly affected. Interestingly, protein changes at the cell surface only partly correlated with changes in the secretome. Several altered proteins were validated by immunoblots in neurons and mouse brains. Apparent nonsubstrates, such as TSPAN6, were also increased, indicating that BACE1-inhibition may lead to unexpected secondary effects. In summary, SUSPECS is broadly useful for determination of the surface glycoproteome and its correlation with the secretome.
Collapse
Affiliation(s)
- Julia Herber
- From the ‡German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,§Neuroproteomics, School of Medicine, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Jasenka Njavro
- From the ‡German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,§Neuroproteomics, School of Medicine, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Regina Feederle
- From the ‡German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,¶Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.,‖Institute for Diabetes and Obesity, Monoclonal Antibody Research Group, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Munich, Germany
| | - Ute Schepers
- **Karlsruhe Institute of Technology (KIT), Institute of Toxicology and Genetics (ITG), Karlsruhe, Germany
| | - Ulrike C Müller
- ‡‡Department of Functional Genomics, Institute for Pharmacy and Molecular Biotechnology, Heidelberg University Heidelberg, Germany
| | - Stefan Bräse
- **Karlsruhe Institute of Technology (KIT), Institute of Toxicology and Genetics (ITG), Karlsruhe, Germany
| | - Stephan A Müller
- From the ‡German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,§Neuroproteomics, School of Medicine, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Stefan F Lichtenthaler
- From the ‡German Center for Neurodegenerative Diseases (DZNE), Munich, Germany; .,§Neuroproteomics, School of Medicine, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.,¶Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.,§§Institute for Advanced Study, Technische Universität München, Munich, Germany
| |
Collapse
|
21
|
Begcevic I, Brinc D, Brown M, Martinez-Morillo E, Goldhardt O, Grimmer T, Magdolen V, Batruch I, Diamandis EP. Brain-related proteins as potential CSF biomarkers of Alzheimer's disease: A targeted mass spectrometry approach. J Proteomics 2018; 182:12-20. [PMID: 29684683 DOI: 10.1016/j.jprot.2018.04.027] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 03/15/2018] [Accepted: 04/17/2018] [Indexed: 12/30/2022]
Abstract
Alzheimer's disease (AD) is the most common cause of dementia, characterized by progressive cognitive decline. The main disease hallmarks include amyloid beta aggregates and neurofibrillary tangles. Brain pathology is reflected in cerebrospinal fluid (CSF); the core biomarkers amyloid beta 1-42, total and phosphorylated tau protein levels are changed, relative to cognitively normal elderly. Still, there is a need for additional biomarkers which could identify disease more accurately and at an earlier stage, predict severity and be used in research settings. Here we evaluated 30 brain-related proteins as candidate biomarkers of AD. Proteins were quantified in CSF samples from cognitively healthy individuals (n = 23) and patients with mild cognitive impairment (MCI) due to AD (n = 20) or dementia due to AD (n = 10) using selected reaction monitoring mass spectrometry assays. APLP1 protein was increased in MCI relative to control (p < 0.001). The best discrimination between MCI vs. controls was observed with a model combining APLP1 and SPP1 proteins (area under the curve, AUC = 0.84). The strongest associations between protein abundance and disease severity were found for APLP1, CNTN2 and SPP1 proteins, which had a significant correlation with MMSE and CDR tests (p < 0.05). This study identifies new proteins with biomarker potential at various stages of AD severity. SIGNIFICANCE The current study evaluated 30 brain-related, highly specific proteins as candidate biomarkers of AD diagnosis. Protein APLP1 showed promise as early AD biomarker; protein panel APLP1 and SPP1 had the best diagnostic potential in discriminating MCI from control group, while proteins APLP1, SPP1 and CNTN2 may be indicators of disease progression, demonstrating weak to moderate correlation with cognitive tests. This study therefore identifies new proteins with biomarker potential at early AD stage. If the performance of proposed biomarkers is further confirmed, these proteins may add value in the clinic or clinical trial settings as diagnostic biomarkers (alone or in combination with the existing biomarkers) of the prodromal AD stage, and in monitoring disease progression.
Collapse
Affiliation(s)
- Ilijana Begcevic
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada; Department of Pathology & Laboratory Medicine, Mount Sinai Hospital, Toronto, Canada
| | - Davor Brinc
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada; Department of Pathology & Laboratory Medicine, Mount Sinai Hospital, Toronto, Canada; Department of Clinical Biochemistry, University Health Network, Toronto, Canada
| | - Marshall Brown
- Department of Biostatistics, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Eduardo Martinez-Morillo
- Laboratory of Medicine, Department of Clinical Biochemistry, Hospital Universitario Central, Oviedo, Spain
| | - Oliver Goldhardt
- Department of Psychiatry and Psychotherapy, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Timo Grimmer
- Department of Psychiatry and Psychotherapy, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Viktor Magdolen
- Department of Obstetrics and Gynecology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Ihor Batruch
- Department of Pathology & Laboratory Medicine, Mount Sinai Hospital, Toronto, Canada
| | - Eleftherios P Diamandis
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada; Department of Pathology & Laboratory Medicine, Mount Sinai Hospital, Toronto, Canada; Department of Clinical Biochemistry, University Health Network, Toronto, Canada.
| |
Collapse
|
22
|
β-Secretase BACE1 Promotes Surface Expression and Function of Kv3.4 at Hippocampal Mossy Fiber Synapses. J Neurosci 2018; 38:3480-3494. [PMID: 29507146 DOI: 10.1523/jneurosci.2643-17.2018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 02/19/2018] [Accepted: 02/28/2018] [Indexed: 12/16/2022] Open
Abstract
The β-secretase β-site APP-cleaving enzyme 1 (BACE1) is deemed a major culprit in Alzheimer's disease, but accumulating evidence indicates that there is more to the enzyme than driving the amyloidogenic processing of the amyloid precursor protein. For example, BACE1 has emerged as an important regulator of neuronal activity through proteolytic and, most unexpectedly, also through nonproteolytic interactions with several ion channels. Here, we identify and characterize the voltage-gated K+ channel 3.4 (Kv3.4) as a new and functionally relevant interaction partner of BACE1. Kv3.4 gives rise to A-type current with fast activating and inactivating kinetics and serves to repolarize the presynaptic action potential. We found that BACE1 and Kv3.4 are highly enriched and remarkably colocalized in hippocampal mossy fibers (MFs). In BACE1-/- mice of either sex, Kv3.4 surface expression was significantly reduced in the hippocampus and, in synaptic fractions thereof, Kv3.4 was specifically diminished, whereas protein levels of other presynaptic K+ channels such as KCa1.1 and KCa2.3 remained unchanged. The apparent loss of presynaptic Kv3.4 affected the strength of excitatory transmission at the MF-CA3 synapse in hippocampal slices of BACE1-/- mice when probed with the Kv3 channel blocker BDS-I. The effect of BACE1 on Kv3.4 expression and function should be bidirectional, as predicted from a heterologous expression system, in which BACE1 cotransfection produced a concomitant upregulation of Kv3.4 surface level and current based on a physical interaction between the two proteins. Our data show that, by targeting Kv3.4 to presynaptic sites, BACE1 endows the terminal with a powerful means to regulate the strength of transmitter release.SIGNIFICANCE STATEMENT The β-secretase β-site APP-cleaving enzyme 1 (BACE1) is infamous for its crucial role in the pathogenesis of Alzheimer's disease, but its physiological functions in the intact nervous system are only gradually being unveiled. Here, we extend previous work implicating BACE1 in the expression and function of voltage-gated Na+ and K+ channels. Specifically, we characterize voltage-gated K+ channel 3.4 (Kv3.4), a presynaptic K+ channel required for action potential repolarization, as a novel interaction partner of BACE1 at the mossy fiber (MF)-CA3 synapse of the hippocampus. BACE1 promotes surface expression of Kv3.4 at MF terminals, most likely by physically associating with the channel protein in a nonenzymatic fashion. We advance the BACE1-Kv3.4 interaction as a mechanism to strengthen the temporal control over transmitter release from MF terminals.
Collapse
|
23
|
Izadi F, Soheilifar MH. Exploring Potential Biomarkers Underlying Pathogenesis of Alzheimer's Disease by Differential Co-expression Analysis. Avicenna J Med Biotechnol 2018; 10:233-241. [PMID: 30555656 PMCID: PMC6252023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Alzheimer's Disease (AD) is the most common form of dementia in the elderly. Due to the facts that biological causes of AD are complex in addition to increasing rates of AD worldwide, a deeper understanding of AD etiology is required for AD treatment and diagnosis. METHODS To identify molecular pathological alterations in AD brains, GSE36980 series containing microarray data samples from temporal cortex, frontal cortex and hippocampus were downloaded from Gene Expression Omnibus (GEO) database and valid gene symbols were subjected to building a gene co-expression network by a bioinformatics tool known as differential regulation from differential co-expression (DCGL) software package. Then, a network-driven integrative analysis was performed to find significant genes and underlying biological terms. RESULTS A total of 17088 unique genes were parsed into three independent differential co-expression networks. As a result, a small number of differentially co-regulated genes mostly in frontal and hippocampus lobs were detected as potential biomarkers related to AD brains. Ultimately differentially co-regulated genes were enriched in biological terms including response to lipid and fatty acid and pathways mainly signaling pathway such as G-protein signaling pathway and glutamate receptor groups II and III. By conducting co-expression analysis, our study identified multiple genes that may play an important role in the pathogenesis of AD. CONCLUSION The study aimed to provide a systematic understanding of the potential relationships among these genes and it is hoped that it could aid in AD biomarker discovery.
Collapse
Affiliation(s)
- Fereshteh Izadi
- Department of Genetics, Evolution and Environment, Darwin Building, University College London (UCL), London, UK,Corresponding author: Fereshteh Izadi, PhD, Department of Genetics, Evolution and Environment, Darwin Building, University College London (UCL), Gower Street, London WC1E 6BT, UK, Tel: +44 7846280861, E-mail:
| | | |
Collapse
|
24
|
Detection of contactin-2 in cerebrospinal fluid (CSF) of patients with Alzheimer's disease using Fluorescence Correlation Spectroscopy (FCS). Clin Biochem 2017; 50:1061-1066. [DOI: 10.1016/j.clinbiochem.2017.08.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 08/16/2017] [Accepted: 08/27/2017] [Indexed: 11/19/2022]
|
25
|
Expression of Gas1 in Mouse Brain: Release and Role in Neuronal Differentiation. Cell Mol Neurobiol 2017; 38:841-859. [PMID: 29110208 DOI: 10.1007/s10571-017-0559-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 10/14/2017] [Indexed: 10/18/2022]
Abstract
Growth arrest-specific 1 (Gas1) is a pleiotropic protein that induces apoptosis of tumor cells and has important roles during development. Recently, the presence of two forms of Gas1 was reported: one attached to the cell membrane by a GPI anchor; and a soluble extracellular form shed by cells. Previously, we showed that Gas1 is expressed in different areas of the adult mouse CNS. Here, we report the levels of Gas1 mRNA protein in different regions and analyzed its expressions in glutamatergic, GABAergic, and dopaminergic neurons. We found that Gas1 is expressed in GABAergic and glutamatergic neurons in the Purkinje-molecular layer of the cerebellum, hippocampus, thalamus, and fastigial nucleus, as well as in dopaminergic neurons of the substantia nigra. In all cases, Gas1 was found in the cell bodies, but not in the neuropil. The Purkinje and the molecular layers show the highest levels of Gas1, whereas the granule cell layer has low levels. Moreover, we detected the expression and release of Gas1 from primary cultures of Purkinje cells and from hippocampal neurons as well as from neuronal cell lines, but not from cerebellar granular cells. In addition, using SH-SY5Y cells differentiated with retinoic acid as a neuronal model, we found that extracellular Gas1 promotes neurite outgrowth, increases the levels of tyrosine hydroxylase, and stimulates the inhibition of GSK3β. These findings demonstrate that Gas1 is expressed and released by neurons and promotes differentiation, suggesting an important role for Gas1 in cellular signaling in the CNS.
Collapse
|
26
|
Tallon C, Farah MH. Beta secretase activity in peripheral nerve regeneration. Neural Regen Res 2017; 12:1565-1574. [PMID: 29171411 PMCID: PMC5696827 DOI: 10.4103/1673-5374.217319] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/26/2017] [Indexed: 12/13/2022] Open
Abstract
While the peripheral nervous system has the capacity to regenerate following a nerve injury, it is often at a slow rate and results in unsatisfactory recovery, leaving patients with reduced function. Many regeneration associated genes have been identified over the years, which may shed some insight into how we can manipulate this intrinsic regenerative ability to enhance repair following peripheral nerve injuries. Our lab has identified the membrane bound protease beta-site amyloid precursor protein-cleaving enzyme 1 (BACE1), or beta secretase, as a potential negative regulator of peripheral nerve regeneration. When beta secretase activity levels are abolished via a null mutation in mice, peripheral regeneration is enhanced following a sciatic nerve crush injury. Conversely, when activity levels are greatly increased by overexpressing beta secretase in mice, nerve regeneration and functional recovery are impaired after a sciatic nerve crush injury. In addition to our work, many substrates of beta secretase have been found to be involved in regulating neurite outgrowth and some have even been identified as regeneration associated genes. In this review, we set out to discuss BACE1 and its substrates with respect to axonal regeneration and speculate on the possibility of utilizing BACE1 inhibitors to enhance regeneration following acute nerve injury and potential uses in peripheral neuropathies.
Collapse
Affiliation(s)
- Carolyn Tallon
- Department of Neurology at Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Mohamed H. Farah
- Department of Neurology at Johns Hopkins School of Medicine, Baltimore, MD, USA
| |
Collapse
|
27
|
Abstract
Contactin-2/transiently expressed axonal surface glycoprotein-1 (TAG-1) is a cell adhesion molecule belonging to the immunoglobulin superfamily (IgSF). It has six immunoglobulin-like extracellular domains and four fibronectin III-like ones, with anchoring to the cell membrane through glycosylphosphatidyl inositol. Contactin-2/TAG-1 is expressed in specific neurons transiently on the axonal surface during the fetal period. In postnatal stages, Contactin-2/TAG-1 is expressed in cerebellar granule cells, hippocampal pyramidal cells, and the juxtaparanodal regions of myelinated nerve fibers. In the embryonic nervous system, Contactin-2/TAG-1 plays important roles in axonal elongation, axonal guidance, and cellular migration. In the postnatal nervous system, it also plays an essential role in the formation of myelinated nerve fibers. Moreover, Contactin-2/TAG-1 has been linked to autoimmune diseases of the human nervous system. Taken together, Contactin-2/TAG-1 plays a central role in a variety of functions from development to disease.
Collapse
Affiliation(s)
- Tomoyuki Masuda
- a Doctoral and Master's Programs in Kansei, Behavioral and Brain Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba , Ibaraki , Japan.,b Department of Neurology , Faculty of Medicine, University of Tsukuba , Ibaraki , Japan.,c Department of Neurobiology , Faculty of Medicine, University of Tsukuba , Ibaraki , Japan
| |
Collapse
|
28
|
Jiaranaikulwanitch J, Tadtong S, Govitrapong P, Fokin VV, Vajragupta O. Neuritogenic activity of bi-functional bis-tryptoline triazole. Bioorg Med Chem 2016; 25:1195-1201. [PMID: 28043778 DOI: 10.1016/j.bmc.2016.12.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 12/16/2016] [Accepted: 12/20/2016] [Indexed: 10/20/2022]
Abstract
Alzheimer's disease (AD) is a common neurodegenerative disorder, one of the hallmarks of which is the deposition of aggregated β-amyloid peptides (Aβ40,42) as plaques in the brain. Oligomers of these peptides have been reported to be toxic and to inhibit neurite outgrowth, as evidenced by neurite dystrophy and significant loss of synaptic connectivity of neurons in the AD brain resulting in cognitive decline. These peptides also react with biological metal in the brain to generate free radicals, thereby aggravating neuronal cell injury and death. Herein, multifunctional triazole-based compounds acting on multiple targets, namely β-secretase (BACE1), β-amyloid peptides (Aβ) as well as those possessing metal chelation and antioxidant properties, were developed and evaluated for neuritogenic activity in P19-derived neurons. At the non-cytotoxic concentration (1nM), all multifunctional compounds significantly enhanced neurite outgrowth. New bis-tryptoline triazole (BTT) increased the neurite length and neurite number, by 93.25% and 136.09% over the control, respectively. This finding demonstrates the ability of multifunctional compounds targeting Aβ to enhance neurite outgrowth in addition to their neuroprotective action.
Collapse
Affiliation(s)
- Jutamas Jiaranaikulwanitch
- Department of Pharmaceutical Sciences, Faculty of Pharmacy, Chiang Mai University, Chiang Mai 50200, Thailand; Center of Excellent for Innovation in Drug Design and Discovery and Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Mahidol University, 447 Sri-Ayudhya Road, Bangkok 10400, Thailand.
| | - Sarin Tadtong
- Department of Pharmacognosy, Faculty of Pharmacy, Srinakharinwirot University, 63 Moo 7 Rangsit-Nakhonnayok Road, Ongkharak, Nakhonnayok 26120, Thailand
| | - Piyarat Govitrapong
- Center for Neuroscience, Faculty of Science, Mahidol University, 272 Rama VI Road, Rajathevi, Bangkok 10400, Thailand
| | - Valery V Fokin
- Department of Chemistry, The Scripps Research Institute, 10500 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Opa Vajragupta
- Center of Excellent for Innovation in Drug Design and Discovery and Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Mahidol University, 447 Sri-Ayudhya Road, Bangkok 10400, Thailand
| |
Collapse
|
29
|
Gennarini G, Bizzoca A, Picocci S, Puzzo D, Corsi P, Furley AJW. The role of Gpi-anchored axonal glycoproteins in neural development and neurological disorders. Mol Cell Neurosci 2016; 81:49-63. [PMID: 27871938 DOI: 10.1016/j.mcn.2016.11.006] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Revised: 11/10/2016] [Accepted: 11/14/2016] [Indexed: 01/06/2023] Open
Abstract
This review article focuses on the Contactin (CNTN) subset of the Immunoglobulin supergene family (IgC2/FNIII molecules), whose components share structural properties (the association of Immunoglobulin type C2 with Fibronectin type III domains), as well as a general role in cell contact formation and axonal growth control. IgC2/FNIII molecules include 6 highly related components (CNTN 1-6), associated with the cell membrane via a Glycosyl Phosphatidyl Inositol (GPI)-containing lipid tail. Contactin 1 and Contactin 2 share ~50 (49.38)% identity at the aminoacid level. They are components of the cell surface, from which they may be released in soluble forms. They bind heterophilically to multiple partners in cis and in trans, including members of the related L1CAM family and of the Neurexin family Contactin-associated proteins (CNTNAPs or Casprs). Such interactions are important for organising the neuronal membrane, as well as for modulating the growth and pathfinding of axon tracts. In addition, they also mediate the functional maturation of axons by promoting their interactions with myelinating cells at the nodal, paranodal and juxtaparanodal regions. Such interactions also mediate differential ionic channels (both Na+ and K+) distribution, which is of critical relevance in the generation of the peak-shaped action potential. Indeed, thanks to their interactions with Ankyrin G, Na+ channels map within the nodal regions, where they drive axonal depolarization. However, no ionic channels are found in the flanking Contactin1-containing paranodal regions, where CNTN1 interactions with Caspr1 and with the Ig superfamily component Neurofascin 155 in cis and in trans, respectively, build a molecular barrier between the node and the juxtaparanode. In this region K+ channels are clustered, depending upon molecular interactions with Contactin 2 and with Caspr2. In addition to these functions, the Contactins appear to have also a role in degenerative and inflammatory disorders: indeed Contactin 2 is involved in neurodegenerative disorders with a special reference to the Alzheimer disease, given its ability to work as a ligand of the Alzheimer Precursor Protein (APP), which results in increased Alzheimer Intracellular Domain (AICD) release in a γ-secretase-dependent manner. On the other hand Contactin 1 drives Notch signalling activation via the Hes pathway, which could be consistent with its ability to modulate neuroinflammation events, and with the possibility that Contactin 1-dependent interactions may participate to the pathogenesis of the Multiple Sclerosis and of other inflammatory disorders.
Collapse
Affiliation(s)
- Gianfranco Gennarini
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, Medical School, University of Bari Policlinico. Piazza Giulio Cesare. I-70124 Bari, Italy.
| | - Antonella Bizzoca
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, Medical School, University of Bari Policlinico. Piazza Giulio Cesare. I-70124 Bari, Italy
| | - Sabrina Picocci
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, Medical School, University of Bari Policlinico. Piazza Giulio Cesare. I-70124 Bari, Italy
| | - Daniela Puzzo
- Department of Biomedical and Biotechnological Sciences, University of Catania, Italy
| | - Patrizia Corsi
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, Medical School, University of Bari Policlinico. Piazza Giulio Cesare. I-70124 Bari, Italy
| | - Andrew J W Furley
- Department of Biomedical Science, University of Sheffield, Western Bank, Sheffield S10 2NT, UK
| |
Collapse
|
30
|
Pigoni M, Wanngren J, Kuhn PH, Munro KM, Gunnersen JM, Takeshima H, Feederle R, Voytyuk I, De Strooper B, Levasseur MD, Hrupka BJ, Müller SA, Lichtenthaler SF. Seizure protein 6 and its homolog seizure 6-like protein are physiological substrates of BACE1 in neurons. Mol Neurodegener 2016; 11:67. [PMID: 27716410 PMCID: PMC5053352 DOI: 10.1186/s13024-016-0134-z] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2016] [Accepted: 09/28/2016] [Indexed: 01/22/2023] Open
Abstract
Background The protease BACE1 (beta-site APP cleaving enzyme) is a major drug target in Alzheimer’s disease. However, BACE1 therapeutic inhibition may cause unwanted adverse effects due to its additional functions in the nervous system, such as in myelination and neuronal connectivity. Additionally, recent proteomic studies investigating BACE1 inhibition in cell lines and cultured murine neurons identified a wider range of neuronal membrane proteins as potential BACE1 substrates, including seizure protein 6 (SEZ6) and its homolog SEZ6L. Methods and results We generated antibodies against SEZ6 and SEZ6L and validated these proteins as BACE1 substrates in vitro and in vivo. Levels of the soluble, BACE1-cleaved ectodomain of both proteins (sSEZ6, sSEZ6L) were strongly reduced upon BACE1 inhibition in primary neurons and also in vivo in brains of BACE1-deficient mice. BACE1 inhibition increased neuronal surface levels of SEZ6 and SEZ6L as shown by cell surface biotinylation, demonstrating that BACE1 controls surface expression of both proteins. Moreover, mass spectrometric analysis revealed that the BACE1 cleavage site in SEZ6 is located in close proximity to the membrane, similar to the corresponding cleavage site in SEZ6L. Finally, an improved method was developed for the proteomic analysis of murine cerebrospinal fluid (CSF) and was applied to CSF from BACE-deficient mice. Hereby, SEZ6 and SEZ6L were validated as BACE1 substrates in vivo by strongly reduced levels in the CSF of BACE1-deficient mice. Conclusions This study demonstrates that SEZ6 and SEZ6L are physiological BACE1 substrates in the murine brain and suggests that sSEZ6 and sSEZ6L levels in CSF are suitable markers to monitor BACE1 inhibition in mice. Electronic supplementary material The online version of this article (doi:10.1186/s13024-016-0134-z) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Martina Pigoni
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Neuroproteomics, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Johanna Wanngren
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Neuroproteomics, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Peer-Hendrik Kuhn
- Neuroproteomics, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.,Institute for Advanced Study, Technische Universität München, Munich, Germany.,Institute for Pathology und Pathological Anatomy, Technische Universität München, Munich, Germany
| | - Kathryn M Munro
- Department of Anatomy and Neuroscience, University of Melbourne, Victoria, Australia
| | - Jenny M Gunnersen
- Department of Anatomy and Neuroscience, University of Melbourne, Victoria, Australia.,The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Victoria, Australia
| | - Hiroshi Takeshima
- Division of Pharmaceutical Sciences, Graduate School and Faculty of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Regina Feederle
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Institute for Diabetes and Obesity, Monoclonal Antibody Research Group, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Iryna Voytyuk
- VIB Center for the Biology of Disease, Leuven, Belgium
| | - Bart De Strooper
- VIB Center for the Biology of Disease, Leuven, Belgium.,Center for Human Genetics, and Leuven Institute for Neurodegenerative Diseases (LIND), University of Leuven (KU Leuven), Leuven, Belgium.,Institute of Neurology, University College London, London, UK
| | | | - Brian J Hrupka
- Department of Neuroscience, Janssen Pharmaceutica NV, Beerse, Belgium
| | - Stephan A Müller
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Neuroproteomics, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Stefan F Lichtenthaler
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany. .,Neuroproteomics, Klinikum rechts der Isar, Technische Universität München, Munich, Germany. .,Institute for Advanced Study, Technische Universität München, Munich, Germany. .,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.
| |
Collapse
|
31
|
Rao SNR, Pearse DD. Regulating Axonal Responses to Injury: The Intersection between Signaling Pathways Involved in Axon Myelination and The Inhibition of Axon Regeneration. Front Mol Neurosci 2016; 9:33. [PMID: 27375427 PMCID: PMC4896923 DOI: 10.3389/fnmol.2016.00033] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 05/02/2016] [Indexed: 01/06/2023] Open
Abstract
Following spinal cord injury (SCI), a multitude of intrinsic and extrinsic factors adversely affect the gene programs that govern the expression of regeneration-associated genes (RAGs) and the production of a diversity of extracellular matrix molecules (ECM). Insufficient RAG expression in the injured neuron and the presence of inhibitory ECM at the lesion, leads to structural alterations in the axon that perturb the growth machinery, or form an extraneous barrier to axonal regeneration, respectively. Here, the role of myelin, both intact and debris, in antagonizing axon regeneration has been the focus of numerous investigations. These studies have employed antagonizing antibodies and knockout animals to examine how the growth cone of the re-growing axon responds to the presence of myelin and myelin-associated inhibitors (MAIs) within the lesion environment and caudal spinal cord. However, less attention has been placed on how the myelination of the axon after SCI, whether by endogenous glia or exogenously implanted glia, may alter axon regeneration. Here, we examine the intersection between intracellular signaling pathways in neurons and glia that are involved in axon myelination and axon growth, to provide greater insight into how interrogating this complex network of molecular interactions may lead to new therapeutics targeting SCI.
Collapse
Affiliation(s)
- Sudheendra N R Rao
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine Miami, FL, USA
| | - Damien D Pearse
- The Miami Project to Cure Paralysis, University of Miami Miller School of MedicineMiami, FL, USA; The Department of Neurological Surgery, University of Miami Miller School of MedicineMiami, FL, USA; The Neuroscience Program, University of Miami Miller School of MedicineMiami, FL, USA; The Interdisciplinary Stem Cell Institute, University of Miami Miller School of MedicineMiami, FL, USA; Bruce W. Carter Department of Veterans Affairs Medical CenterMiami, FL, USA
| |
Collapse
|
32
|
Yan R, Fan Q, Zhou J, Vassar R. Inhibiting BACE1 to reverse synaptic dysfunctions in Alzheimer's disease. Neurosci Biobehav Rev 2016; 65:326-40. [PMID: 27044452 PMCID: PMC4856578 DOI: 10.1016/j.neubiorev.2016.03.025] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 03/25/2016] [Accepted: 03/29/2016] [Indexed: 12/21/2022]
Abstract
Over the past two decades, many studies have identified significant contributions of toxic β-amyloid peptides (Aβ) to the etiology of Alzheimer's disease (AD), which is the most common age-dependent neurodegenerative disease. AD is also recognized as a disease of synaptic failure. Aβ, generated by sequential proteolytic cleavages of amyloid precursor protein (APP) by BACE1 and γ-secretase, is one of major culprits that cause this failure. In this review, we summarize current findings on how BACE1-cleaved APP products impact learning and memory through proteins localized on glutamatergic, GABAergic, and dopaminergic synapses. Considering the broad effects of Aβ on all three types of synapses, BACE1 inhibition emerges as a practical approach for ameliorating Aβ-mediated synaptic dysfunctions. Since BACE1 inhibitory drugs are currently in clinical trials, this review also discusses potential complications arising from BACE1 inhibition. We emphasize that the benefits of BACE1 inhibitory drugs will outweigh the concerns.
Collapse
Affiliation(s)
- Riqiang Yan
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
| | - Qingyuan Fan
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - John Zhou
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Robert Vassar
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
| |
Collapse
|
33
|
Synaptic Cell Adhesion Molecules in Alzheimer's Disease. Neural Plast 2016; 2016:6427537. [PMID: 27242933 PMCID: PMC4868906 DOI: 10.1155/2016/6427537] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 04/13/2016] [Indexed: 12/14/2022] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative brain disorder associated with the loss of synapses between neurons in the brain. Synaptic cell adhesion molecules are cell surface glycoproteins which are expressed at the synaptic plasma membranes of neurons. These proteins play key roles in formation and maintenance of synapses and regulation of synaptic plasticity. Genetic studies and biochemical analysis of the human brain tissue, cerebrospinal fluid, and sera from AD patients indicate that levels and function of synaptic cell adhesion molecules are affected in AD. Synaptic cell adhesion molecules interact with Aβ, a peptide accumulating in AD brains, which affects their expression and synaptic localization. Synaptic cell adhesion molecules also regulate the production of Aβ via interaction with the key enzymes involved in Aβ formation. Aβ-dependent changes in synaptic adhesion affect the function and integrity of synapses suggesting that alterations in synaptic adhesion play key roles in the disruption of neuronal networks in AD.
Collapse
|
34
|
Hu X, Fan Q, Hou H, Yan R. Neurological dysfunctions associated with altered BACE1-dependent Neuregulin-1 signaling. J Neurochem 2016; 136:234-49. [PMID: 26465092 PMCID: PMC4833723 DOI: 10.1111/jnc.13395] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 09/23/2015] [Accepted: 09/25/2015] [Indexed: 01/09/2023]
Abstract
Inhibition of BACE1 is being pursued as a therapeutic target to treat patients suffering from Alzheimer's disease because BACE1 is the sole β-secretase that generates β-amyloid peptide. Knowledge regarding other cellular functions of BACE1 is therefore critical for the safe use of BACE1 inhibitors in human patients. Neuregulin-1 (Nrg1) is a BACE1 substrate and BACE1 cleavage of Nrg1 is critical for signaling functions in myelination, remyelination, synaptic plasticity, normal psychiatric behaviors, and maintenance of muscle spindles. This review summarizes the most recent discoveries associated with BACE1-dependent Nrg1 signaling in these areas. This body of knowledge will help to provide guidance for preventing unwanted Nrg1-based side effects following BACE1 inhibition in humans. To initiate its signaling cascade, membrane anchored Neuregulin (Nrg), mainly type I and III β1 Nrg1 isoforms and Nrg3, requires ectodomain shedding. BACE1 is one of such indispensable sheddases to release the functional Nrg signaling fragment. The dependence of Nrg on the cleavage by BACE1 is best manifested by disrupting the critical role of Nrg in the control of axonal myelination, schizophrenic behaviors as well as the formation and maintenance of muscle spindles.
Collapse
Affiliation(s)
- Xiangyou Hu
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195
| | - Qingyuan Fan
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195
| | - Hailong Hou
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195
| | - Riqiang Yan
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195
| |
Collapse
|
35
|
Lin N, Chen LM, Pan XD, Zhu YG, Zhang J, Shi YQ, Chen XC. Tripchlorolide Attenuates β-amyloid Generation via Suppressing PPARγ-Regulated BACE1 Activity in N2a/APP695 Cells. Mol Neurobiol 2015; 53:6397-6406. [PMID: 26582466 DOI: 10.1007/s12035-015-9542-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 11/11/2015] [Indexed: 12/28/2022]
Abstract
Due to its apparent rate-limiting function, BACE1 (β-secretase) appears to be a prime target for prevention of amyloid-β (Aβ) generation in brains with Alzheimer's disease (AD). The activity of BACE1 is regulated by peroxisome proliferator-activated receptor-γ (PPARγ), a transcription factor binding site of the BACE1 promoter, indicating that PPARγ may be a potential target for AD treatment. Several studies have demonstrated that PPARγ activation is involved in the immunostimulation of amyloid-β precursor protein processing by nonsteroidal anti-inflammatory drugs (NSAIDs). The present study found that tripchlorolide (T4), with a similar chemical structure to that of NSAIDs, decreased the levels of Aβ secreted in N2a-APP695 cells. T4 treatment reduced the mRNA and protein levels of BACE1 and the protein level of sAPPβ, a cleaved N-terminal fragment of APP by BACE1. The treatment also translocated PPARγ from cytoplasm to nuclear. Intriguingly, T4, like pioglitazone (a PPARγ agonist), suppressed the BACE1 activity in N2a-APP695 cells, which was attenuated by GW9662 (a PPARγ antagonist). These results indicate that T4 may be a PPARγ agonist to enhance the binding of nuclear PPARγ to the BACE1 promoter, which may in turn inhibit the transcription and translation of BACE1, suppress the activity of BACE1, and ultimately attenuate the generation of Aβ. Due to its capability to alter Aβ generation and to protect central neural system against the neurotoxicity of Aβ, T4 may serve as a promising agent in modulating Aβ-related pathology in Alzheimer's disease.
Collapse
Affiliation(s)
- Nan Lin
- Department of Neurology and Geriatrics, Fujian Institute of Geriatrics, Affiliated Union Hospital of Fujian Medical University, 29 Xinquan Road, Fuzhou, Fujian, 350001, People's Republic of China.,Key Laboratory of Brain Aging and Neurodegenerative Disease, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, 29 Xinquan Road, Fuzhou, 350001, China
| | - Li-Min Chen
- Department of Neurology and Geriatrics, Fujian Institute of Geriatrics, Affiliated Union Hospital of Fujian Medical University, 29 Xinquan Road, Fuzhou, Fujian, 350001, People's Republic of China.,Key Laboratory of Brain Aging and Neurodegenerative Disease, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, 29 Xinquan Road, Fuzhou, 350001, China
| | - Xiao-Dong Pan
- Department of Neurology and Geriatrics, Fujian Institute of Geriatrics, Affiliated Union Hospital of Fujian Medical University, 29 Xinquan Road, Fuzhou, Fujian, 350001, People's Republic of China.,Key Laboratory of Brain Aging and Neurodegenerative Disease, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, 29 Xinquan Road, Fuzhou, 350001, China
| | - Yuan-Gui Zhu
- Department of Neurology and Geriatrics, Fujian Institute of Geriatrics, Affiliated Union Hospital of Fujian Medical University, 29 Xinquan Road, Fuzhou, Fujian, 350001, People's Republic of China.,Key Laboratory of Brain Aging and Neurodegenerative Disease, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, 29 Xinquan Road, Fuzhou, 350001, China
| | - Jing Zhang
- Department of Neurology and Geriatrics, Fujian Institute of Geriatrics, Affiliated Union Hospital of Fujian Medical University, 29 Xinquan Road, Fuzhou, Fujian, 350001, People's Republic of China.,Key Laboratory of Brain Aging and Neurodegenerative Disease, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, 29 Xinquan Road, Fuzhou, 350001, China
| | - Yan-Qing Shi
- Department of Neurology and Geriatrics, Fujian Institute of Geriatrics, Affiliated Union Hospital of Fujian Medical University, 29 Xinquan Road, Fuzhou, Fujian, 350001, People's Republic of China.,Key Laboratory of Brain Aging and Neurodegenerative Disease, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, 29 Xinquan Road, Fuzhou, 350001, China
| | - Xiao-Chun Chen
- Department of Neurology and Geriatrics, Fujian Institute of Geriatrics, Affiliated Union Hospital of Fujian Medical University, 29 Xinquan Road, Fuzhou, Fujian, 350001, People's Republic of China. .,Key Laboratory of Brain Aging and Neurodegenerative Disease, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, 29 Xinquan Road, Fuzhou, 350001, China.
| |
Collapse
|
36
|
Gautam V, D'Avanzo C, Berezovska O, Tanzi RE, Kovacs DM. Synaptotagmins interact with APP and promote Aβ generation. Mol Neurodegener 2015. [PMID: 26202512 PMCID: PMC4511450 DOI: 10.1186/s13024-015-0028-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Background Accumulation of the β-amyloid peptide (Aβ) is a major pathological hallmark of Alzheimer’s disease (AD). Recent studies have shown that synaptic Aβ toxicity may directly impair synaptic function. However, proteins regulating Aβ generation at the synapse have not been characterized. Here, we sought to identify synaptic proteins that interact with the extracellular domain of APP and regulate Aβ generation. Results Affinity purification-coupled mass spectrometry identified members of the Synaptotagmin (Syt) family as novel interacting proteins with the APP ectodomain in mouse brains. Syt-1, −2 and −9 interacted with APP in cells and in mouse brains in vivo. Using a GST pull-down approach, we have further demonstrated that the Syt interaction site lies in the 108 amino acids linker region between the E1 and KPI domains of APP. Stable overexpression of Syt-1 or Syt-9 with APP in CHO and rat pheochromocytoma cells (PC12) significantly increased APP-CTF and sAPP levels, with a 2 to 3 fold increase in secreted Aβ levels in PC12 cells. Moreover, using a stable knockdown approach to reduce the expression of endogenous Syt-1 in PC12 cells, we have observed a ~ 50 % reduction in secreted Aβ generation. APP processing also decreased in these cells, shown by lower CTF levels. Lentiviral-mediated knock down of endogenous Syt-1 in mouse primary neurons also led to a significant reduction in both Aβ40 and Aβ42 generation. As secreted sAPPβ levels were significantly reduced in PC12 cells lacking Syt-1 expression, our results suggest that Syt-1 regulates Aβ generation by modulating BACE1-mediated cleavage of APP. Conclusion Altogether, our data identify the synaptic vesicle proteins Syt-1 and 9 as novel APP-interacting proteins that promote Aβ generation and thus may play an important role in the pathogenesis of AD. Electronic supplementary material The online version of this article (doi:10.1186/s13024-015-0028-5) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Vivek Gautam
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA.
| | - Carla D'Avanzo
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA.
| | - Oksana Berezovska
- MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA.
| | - Rudolph E Tanzi
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA.
| | - Dora M Kovacs
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA.
| |
Collapse
|
37
|
Chang RYK, Etheridge N, Nouwens AS, Dodd PR. SWATH analysis of the synaptic proteome in Alzheimer's disease. Neurochem Int 2015; 87:1-12. [PMID: 25958317 DOI: 10.1016/j.neuint.2015.04.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 04/20/2015] [Accepted: 04/21/2015] [Indexed: 10/23/2022]
Abstract
Brain tissue from Alzheimer's disease patients exhibits synaptic degeneration in selected regions. Synaptic dysfunction occurs early in the disease and is a primary pathological target for treatment. The molecular mechanisms underlying this degeneration remain unknown. Quantifying the synaptic proteome in autopsy brain and comparing tissue from Alzheimer's disease cases and subjects with normal aging are critical to understanding the molecular mechanisms associated with Alzheimer pathology. We isolated synaptosomes from hippocampus and motor cortex so as to reduce sample complexity relative to whole-tissue homogenates. Synaptosomal extracts were subjected to strong cation exchange (SCX) fractionation to further partition sample complexity; each fraction received SWATH-based information-dependent acquisition to generate a comprehensive peptide-ion library. The expression of synaptic proteins from AD hippocampus and motor cortex was then compared between groups. A total of 2077 unique proteins were identified at a critical local false discovery rate <5%. Thirty of these, including 17 novel proteins, exhibited significant expression differences between cases and controls; these proteins are involved in cellular functions including structural maintenance, signal transduction, autophagy, oxidative stress, and proteasome activity, or they have synaptic-vesicle related or energy-related functions. Differentially expressed proteins were subjected to pathway analysis to identify protein-protein interactions. This revealed that the most perturbed molecular and cellular functions were cellular assembly and organization. Core analysis revealed RhoA signaling to be the top canonical pathway. Network analysis showed that differentially expressed proteins were related to cellular assembly and organization, and cellular function and maintenance. This is the first study to combine SCX fractionation with SWATH analysis. SWATH is a promising new technique that can greatly enhance protein identification in any proteome, and has many other benefits; however, there are limitations yet to be resolved.
Collapse
Affiliation(s)
| | - Naomi Etheridge
- School of Chemistry and Molecular Biosciences, University of Queensland, Australia
| | - Amanda S Nouwens
- School of Chemistry and Molecular Biosciences, University of Queensland, Australia
| | - Peter R Dodd
- School of Chemistry and Molecular Biosciences, University of Queensland, Australia.
| |
Collapse
|
38
|
Chen L, Chu C, Kong X, Huang T, Cai YD. Discovery of new candidate genes related to brain development using protein interaction information. PLoS One 2015; 10:e0118003. [PMID: 25635857 PMCID: PMC4311913 DOI: 10.1371/journal.pone.0118003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 01/03/2015] [Indexed: 12/18/2022] Open
Abstract
Human brain development is a dramatic process composed of a series of complex and fine-tuned spatiotemporal gene expressions. A good comprehension of this process can assist us in developing the potential of our brain. However, we have only limited knowledge about the genes and gene functions that are involved in this biological process. Therefore, a substantial demand remains to discover new brain development-related genes and identify their biological functions. In this study, we aimed to discover new brain-development related genes by building a computational method. We referred to a series of computational methods used to discover new disease-related genes and developed a similar method. In this method, the shortest path algorithm was executed on a weighted graph that was constructed using protein-protein interactions. New candidate genes fell on at least one of the shortest paths connecting two known genes that are related to brain development. A randomization test was then adopted to filter positive discoveries. Of the final identified genes, several have been reported to be associated with brain development, indicating the effectiveness of the method, whereas several of the others may have potential roles in brain development.
Collapse
Affiliation(s)
- Lei Chen
- College of Information Engineering, Shanghai Maritime University, Shanghai 201306, People’s Republic of China
| | - Chen Chu
- Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, People’s Republic of China
| | - Xiangyin Kong
- Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200025, People’s Republic of China
| | - Tao Huang
- Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200025, People’s Republic of China
- * E-mail: (TH); (YDC)
| | - Yu-Dong Cai
- Institute of Systems Biology, Shanghai University, Shanghai 200444, People’s Republic of China
- * E-mail: (TH); (YDC)
| |
Collapse
|
39
|
Puzzo D, Bizzoca A, Loreto C, Guida CA, Gulisano W, Frasca G, Bellomo M, Castorina S, Gennarini G, Palmeri A. Role of F3/contactin expression profile in synaptic plasticity and memory in aged mice. Neurobiol Aging 2015; 36:1702-1715. [PMID: 25659859 DOI: 10.1016/j.neurobiolaging.2015.01.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 12/30/2014] [Accepted: 01/03/2015] [Indexed: 12/14/2022]
Abstract
We have recently shown that overexpression of the F3/contactin adhesive glycoprotein (also known as Contactin-1) promotes neurogenesis in adult hippocampus, which correlates with improved synaptic plasticity and memory. Because F3/contactin levels physiologically decrease with age, here, we aim at investigating whether its overexpression might counteract the cognitive decline in aged animals. For this we use 20- to 24-month-old TAG/F3 transgenic mice in which F3/contactin overexpression is driven by regulatory sequences from the gene encoding the transient axonal glycoprotein TAG-1 throughout development. We show that aged TAG/F3 mice display improved hippocampal long-term potentiation and memory compared with wild-type littermates. The same mice undergo a decrease of neuronal apoptosis at the hippocampal level, which correlated to a decrease of active caspase-3; by contrast, procaspase-3 and Bax as well as the anti-apoptotic and plasticity-related pathway BDNF/CREB/Bcl-2 were rather increased. Interestingly, amyloid-precursor protein processing was shifted toward sAPPα generation, with a decrease of sAPPβ and amyloid-beta levels. Our data confirm that F3/contactin plays a role in hippocampal synaptic plasticity and memory also in aged mice, suggesting that it acts on molecular pathways related to apoptosis and amyloid-beta production.
Collapse
Affiliation(s)
- Daniela Puzzo
- Section of Physiology, Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Antonella Bizzoca
- Section of Physiology, Department of Basic Medical Sciences, Neuroscience and Sensory Organs, University of Bari, Bari, Italy
| | - Carla Loreto
- Section of Anatomy, Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Chiara A Guida
- Section of Physiology, Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Walter Gulisano
- Section of Physiology, Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Giuseppina Frasca
- Section of Physiology, Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Maria Bellomo
- Faculty of Psychology and Educational Sciences, University "Kore", Enna, Italy
| | - Sergio Castorina
- Section of Anatomy, Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Gianfranco Gennarini
- Section of Physiology, Department of Basic Medical Sciences, Neuroscience and Sensory Organs, University of Bari, Bari, Italy.
| | - Agostino Palmeri
- Section of Physiology, Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy.
| |
Collapse
|
40
|
Peripheral nerve proteins as potential autoantigens in acute and chronic inflammatory demyelinating polyneuropathies. Autoimmun Rev 2014; 13:1070-8. [DOI: 10.1016/j.autrev.2014.08.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 06/27/2014] [Indexed: 01/06/2023]
|
41
|
Craig SEL, Brady-Kalnay SM. Regulation of development and cancer by the R2B subfamily of RPTPs and the implications of proteolysis. Semin Cell Dev Biol 2014; 37:108-18. [PMID: 25223585 DOI: 10.1016/j.semcdb.2014.09.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 09/04/2014] [Accepted: 09/05/2014] [Indexed: 01/04/2023]
Abstract
The initial cloning of receptor protein tyrosine phosphatases (RPTPs) was met with excitement because of their hypothesized function in counterbalancing receptor tyrosine kinase signaling. In recent years, members of a subfamily of RPTPs with homophilic cell-cell adhesion capabilities, known as the R2B subfamily, have been shown to have functions beyond that of counteracting tyrosine kinase activity, by independently influencing cell signaling in their own right and by regulating cell adhesion. The R2B subfamily is composed of four members: PTPmu (PTPRM), PTPrho (PTPRT), PTPkappa (PTPRK), and PCP-2 (PTPRU). The effects of this small subfamily of RPTPs is far reaching, influencing several developmental processes and cancer. In fact, R2B RPTPs are predicted to be tumor suppressors and are among the most frequently mutated protein tyrosine phosphatases (PTPs) in cancer. Confounding these conclusions are more recent studies suggesting that proteolysis of the full-length R2B RPTPs result in oncogenic extracellular and intracellular protein fragments. This review discusses the current knowledge of the role of R2B RPTPs in development and cancer, with special detail given to the mechanisms and implications that proteolysis has on R2B RPTP function. We also touch upon the concept of exploiting R2B proteolysis to develop cancer imaging tools, and consider the effects of R2B proteolysis on axon guidance, perineural invasion and collective cell migration.
Collapse
Affiliation(s)
- Sonya E L Craig
- Department of Molecular Biology and Microbiology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106-4960, USA
| | - Susann M Brady-Kalnay
- Department of Molecular Biology and Microbiology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106-4960, USA; Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA.
| |
Collapse
|