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Soelter TM, Howton TC, Clark AD, Oza VH, Lasseigne BN. Altered glia-neuron communication in Alzheimer's Disease affects WNT, p53, and NFkB Signaling determined by snRNA-seq. Cell Commun Signal 2024; 22:317. [PMID: 38849813 PMCID: PMC11157763 DOI: 10.1186/s12964-024-01686-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 05/28/2024] [Indexed: 06/09/2024] Open
Abstract
BACKGROUND Alzheimer's disease is the most common cause of dementia and is characterized by amyloid-β plaques, tau neurofibrillary tangles, and neuronal loss. Although neuronal loss is a primary hallmark of Alzheimer's disease, it is known that non-neuronal cell populations are ultimately responsible for maintaining brain homeostasis and neuronal health through neuron-glia and glial cell crosstalk. Many signaling pathways have been proposed to be dysregulated in Alzheimer's disease, including WNT, TGFβ, p53, mTOR, NFkB, and Pi3k/Akt signaling. Here, we predict altered cell-cell communication between glia and neurons. METHODS Using public snRNA-sequencing data generated from postmortem human prefrontal cortex, we predicted altered cell-cell communication between glia (astrocytes, microglia, oligodendrocytes, and oligodendrocyte progenitor cells) and neurons (excitatory and inhibitory). We confirmed interactions in a second and third independent orthogonal dataset. We determined cell-type-specificity using Jaccard Similarity Index and investigated the downstream effects of altered interactions in inhibitory neurons through gene expression and transcription factor activity analyses of signaling mediators. Finally, we determined changes in pathway activity in inhibitory neurons. RESULTS Cell-cell communication between glia and neurons is altered in Alzheimer's disease in a cell-type-specific manner. As expected, ligands are more cell-type-specific than receptors and targets. We identified ligand-receptor pairs in three independent datasets and found involvement of the Alzheimer's disease risk genes APP and APOE across datasets. Most of the signaling mediators of these interactions were not significantly differentially expressed, however, the mediators that are also transcription factors had differential activity between AD and control. Namely, MYC and TP53, which are associated with WNT and p53 signaling, respectively, had decreased TF activity in Alzheimer's disease, along with decreased WNT and p53 pathway activity in inhibitory neurons. Additionally, inhibitory neurons had both increased NFkB signaling pathway activity and increased TF activity of NFIL3, an NFkB signaling-associated transcription factor. CONCLUSIONS Cell-cell communication between glia and neurons in Alzheimer's disease is altered in a cell-type-specific manner involving Alzheimer's disease risk genes. Signaling mediators had altered transcription factor activity suggesting altered glia-neuron interactions may dysregulate signaling pathways including WNT, p53, and NFkB in inhibitory neurons.
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Affiliation(s)
- Tabea M Soelter
- Department of Cell, Developmental and Integrative Biology, Heersink School of Medicine, The University of Alabama at Birmingham, Birmingham, AL, United States of America
| | - Timothy C Howton
- Department of Cell, Developmental and Integrative Biology, Heersink School of Medicine, The University of Alabama at Birmingham, Birmingham, AL, United States of America
| | - Amanda D Clark
- Department of Cell, Developmental and Integrative Biology, Heersink School of Medicine, The University of Alabama at Birmingham, Birmingham, AL, United States of America
| | - Vishal H Oza
- Department of Cell, Developmental and Integrative Biology, Heersink School of Medicine, The University of Alabama at Birmingham, Birmingham, AL, United States of America
| | - Brittany N Lasseigne
- Department of Cell, Developmental and Integrative Biology, Heersink School of Medicine, The University of Alabama at Birmingham, Birmingham, AL, United States of America.
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Soelter TM, Howton TC, Clark AD, Oza VH, Lasseigne BN. Altered Glia-Neuron Communication in Alzheimer's Disease Affects WNT, p53, and NFkB Signaling Determined by snRNA-seq. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.11.29.569304. [PMID: 38076822 PMCID: PMC10705421 DOI: 10.1101/2023.11.29.569304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/23/2023]
Abstract
Background Alzheimer's disease is the most common cause of dementia and is characterized by amyloid-β plaques, tau neurofibrillary tangles, and neuronal loss. Although neuronal loss is a primary hallmark of Alzheimer's disease, it is known that non-neuronal cell populations are ultimately responsible for maintaining brain homeostasis and neuronal health through neuron-glia and glial cell crosstalk. Many signaling pathways have been proposed to be dysregulated in Alzheimer's disease, including WNT, TGFβ, p53, mTOR, NFkB, and Pi3k/Akt signaling. Here, we predict altered cell-cell communication between glia and neurons. Methods Using public snRNA-sequencing data generated from postmortem human prefrontal cortex, we predicted altered cell-cell communication between glia (astrocytes, microglia, oligodendrocytes, and oligodendrocyte progenitor cells) and neurons (excitatory and inhibitory). We confirmed interactions in a second and third independent orthogonal dataset. We determined cell-type-specificity using Jaccard Similarity Index and investigated the downstream effects of altered interactions in inhibitory neurons through gene expression and transcription factor activity analyses of signaling mediators. Finally, we determined changes in pathway activity in inhibitory neurons. Results Cell-cell communication between glia and neurons is altered in Alzheimer's disease in a cell-type-specific manner. As expected, ligands are more cell-type-specific than receptors and targets. We identified ligand-receptor pairs in three independent datasets and found involvement of the Alzheimer's disease risk genes APP and APOE across datasets. Most of the signaling mediators of these interactions were not differentially expressed, however, the mediators that are also transcription factors had differential activity between AD and control. Namely, MYC and TP53, which are associated with WNT and p53 signaling, respectively, had decreased TF activity in Alzheimer's disease, along with decreased WNT and p53 pathway activity in inhibitory neurons. Additionally, inhibitory neurons had both increased NFkB signaling pathway activity and increased TF activity of NFIL3, an NFkB signaling-associated transcription factor. Conclusions Cell-cell communication between glia and neurons in Alzheimer's disease is altered in a cell-type-specific manner involving Alzheimer's disease risk genes. Signaling mediators had altered transcription factor activity suggesting altered glia-neuron interactions may dysregulate signaling pathways including WNT, p53, and NFkB in inhibitory neurons.
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Affiliation(s)
- Tabea M. Soelter
- Department of Cell, Developmental and Integrative Biology, Heersink School of Medicine, The University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Timothy C. Howton
- Department of Cell, Developmental and Integrative Biology, Heersink School of Medicine, The University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Amanda D. Clark
- Department of Cell, Developmental and Integrative Biology, Heersink School of Medicine, The University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Vishal H. Oza
- Department of Cell, Developmental and Integrative Biology, Heersink School of Medicine, The University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Brittany N. Lasseigne
- Department of Cell, Developmental and Integrative Biology, Heersink School of Medicine, The University of Alabama at Birmingham, Birmingham, Alabama, United States of America
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de La Harpe R, Zagkos L, Gill D, Cronjé HT, Karhunen V. Cerebrospinal and Brain Proteins Implicated in Neuropsychiatric and Risk Factor Traits: Evidence from Mendelian Randomization. Biomedicines 2024; 12:327. [PMID: 38397929 PMCID: PMC10886978 DOI: 10.3390/biomedicines12020327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2024] [Revised: 01/25/2024] [Accepted: 01/27/2024] [Indexed: 02/25/2024] Open
Abstract
Neuropsychiatric disorders present a global health challenge, necessitating an understanding of their molecular mechanisms for therapeutic development. Using Mendelian randomization (MR) analysis, this study explored associations between genetically predicted levels of 173 proteins in cerebrospinal fluid (CSF) and 25 in the brain with 14 neuropsychiatric disorders and risk factors. Follow-up analyses assessed consistency across plasma protein levels and gene expression in various brain regions. Proteins were instrumented using tissue-specific genetic variants, and colocalization analysis confirmed unbiased gene variants. Consistent MR and colocalization evidence revealed that lower cortical expression of low-density lipoprotein receptor-related protein 8, coupled higher abundance in the CSF and plasma, associated with lower fluid intelligence scores and decreased bipolar disorder risk. Additionally, elevated apolipoprotein-E2 and hepatocyte growth factor-like protein in the CSF and brain were related to reduced leisure screen time and lower odds of physical activity, respectively. Furthermore, elevated CSF soluble tyrosine-protein kinase receptor 1 level increased liability to attention deficit hyperactivity disorder and schizophrenia alongside lower fluid intelligence scores. This research provides genetic evidence supporting novel tissue-specific proteomic targets for neuropsychiatric disorders and their risk factors. Further exploration is necessary to understand the underlying biological mechanisms and assess their potential for therapeutic intervention.
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Affiliation(s)
- Roxane de La Harpe
- Unit of Internal Medicine, Department of Medicine, University Hospital of Lausanne, 1011 Lausanne, Switzerland
| | - Loukas Zagkos
- Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, London SW7 2BX, UK; (L.Z.); (D.G.)
| | - Dipender Gill
- Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, London SW7 2BX, UK; (L.Z.); (D.G.)
| | - Héléne T. Cronjé
- Department of Public Health, Section of Epidemiology, University of Copenhagen, 1165 Copenhagen, Denmark;
| | - Ville Karhunen
- Research Unit of Mathematical Sciences, Faculty of Science, University of Oulu, Fi-900014 Oulu, Finland;
- Research Unit of Population Health, Faculty of Medicine, University of Oulu, Fi-900014 Oulu, Finland
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Jaafar AK, Techer R, Chemello K, Lambert G, Bourane S. PCSK9 and the nervous system: a no-brainer? J Lipid Res 2023; 64:100426. [PMID: 37586604 PMCID: PMC10491654 DOI: 10.1016/j.jlr.2023.100426] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 08/08/2023] [Accepted: 08/10/2023] [Indexed: 08/18/2023] Open
Abstract
In the past 20 years, PCSK9 has been shown to play a pivotal role in LDL cholesterol metabolism and cardiovascular health by inducing the lysosomal degradation of the LDL receptor. PCSK9 was discovered by the cloning of genes up-regulated after apoptosis induced by serum deprivation in primary cerebellar neurons, but despite its initial identification in the brain, the precise role of PCSK9 in the nervous system remains to be clearly established. The present article is a comprehensive review of studies published or in print before July 2023 that have investigated the expression pattern of PCSK9, its effects on lipid metabolism as well as its putative roles specifically in the central and peripheral nervous systems, with a special focus on cerebrovascular and neurodegenerative diseases.
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Affiliation(s)
- Ali K Jaafar
- Laboratoire Inserm UMR 1188 DéTROI, Saint-Pierre, La Réunion, France
| | - Romuald Techer
- Laboratoire Inserm UMR 1188 DéTROI, Saint-Pierre, La Réunion, France
| | - Kévin Chemello
- Laboratoire Inserm UMR 1188 DéTROI, Saint-Pierre, La Réunion, France
| | - Gilles Lambert
- Laboratoire Inserm UMR 1188 DéTROI, Saint-Pierre, La Réunion, France; Faculté de Médecine, Université de La Réunion, Saint-Pierre, La Réunion, France.
| | - Steeve Bourane
- Laboratoire Inserm UMR 1188 DéTROI, Saint-Pierre, La Réunion, France
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Şener YZ, Tokgözoğlu L. Pleiotropy of PCSK9: Functions in Extrahepatic Tissues. Curr Cardiol Rep 2023; 25:979-985. [PMID: 37428313 DOI: 10.1007/s11886-023-01918-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/29/2023] [Indexed: 07/11/2023]
Abstract
PURPOSE OF REVIEW Proprotein convertase subtilisin/kexin type 9 (PCSK9) plays a central role in the metabolism of LDL receptors and mainly acts in the liver. However, there are accumulating data that PCSK9 involves in several functions in different organs beyond the liver. Herein we aimed to summarize the effects of PCSK9 in tissues other than the liver. RECENT FINDINGS PCSK9 has crucial roles in heart, brain and kidney in addition to the cholesterol metabolism. Targeting PCSK9 for the treatment of hypercholesterolemia is effective in the prevention from cardiovascular diseases and PCSK9 inhibitors are getting to be administered in more cases. Therefore understanding the effects of PCSK9 in other tissues gained importance in the use of PCSK9 inhibitors era. PCSK9 participates in cardiac, renal, and neurologic functions however, current literature reveals that use of PSCSK9 inhibitors have beneficial or neutral effects on these organs. Inhibition of PCSK9 is assigned to be associated with new onset diabetes in experimental studies whereas real world data with PCSK9 inhibitors established no relationship between PCSK9 inhibitors and new onset diabetes. PCSK9 might be used as a target for the treatment of nephrotic syndrome and heart failure in the future.
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Affiliation(s)
- Yusuf Ziya Şener
- Cardiology Department, Beypazarı State Hospital, Ankara, Turkey.
| | - Lale Tokgözoğlu
- Cardiology Department, Hacettepe University Faculty of Medicine, Ankara, Turkey
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Bell AS, Wagner J, Rosoff DB, Lohoff FW. Proprotein convertase subtilisin/kexin type 9 (PCSK9) in the central nervous system. Neurosci Biobehav Rev 2023; 149:105155. [PMID: 37019248 DOI: 10.1016/j.neubiorev.2023.105155] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 03/29/2023] [Accepted: 04/01/2023] [Indexed: 04/05/2023]
Abstract
The gene encoding proprotein convertase subtilisin/kexin type 9 (PCSK9) and its protein product have been widely studied for their role in cholesterol and lipid metabolism. PCSK9 increases the rate of metabolic degradation of low-density lipoprotein receptors, preventing the diffusion of low-density lipoprotein (LDL) from plasma into cells and contributes to high lipoprotein-bound cholesterol levels in the plasma. While most research has focused on the regulation and disease relevance of PCSK9 to the cardiovascular system and lipid metabolism, there is a growing body of evidence that PCSK9 plays a crucial role in pathogenic processes in other organ systems, including the central nervous system. PCSK9's impact on the brain is not yet fully understood, though several recent studies have sought to illuminate its impact on various neurodegenerative and psychiatric disorders, as well as its connection with ischemic stroke. Cerebral PCSK9 expression is low but is highly upregulated during disease states. Among others, PCSK9 is known to play a role in neurogenesis, neural cell differentiation, central LDL receptor metabolism, neural cell apoptosis, neuroinflammation, Alzheimer's Disease, Alcohol Use Disorder, and stroke. The PCSK9 gene contains several polymorphisms, including both gain-of-function and loss-of-function mutations which profoundly impact normal PCSK9 signaling and cholesterol metabolism. Gain-of-function mutations lead to persistent hypercholesterolemia and poor health outcomes, while loss-of-function mutations generally lead to hypocholesterolemia and may serve as a protective factor against diseases of the liver, cardiovascular system, and central nervous system. Recent genomic studies have sought to identify the end-organ effects of such mutations and continue to identify evidence of a much broader role for PCSK9 in extrahepatic organ systems. Despite this, there remain large gaps in our understanding of PCSK9, its regulation, and its effects on disease risk outside the liver. This review, which incorporates data from a wide range of scientific disciplines and experimental paradigms, is intended to describe PCSK9's role in the central nervous system as it relates to cerebral disease and neuropsychiatric disorders, and to examine the clinical potential of PCSK9 inhibitors and genetic variation in the PCSK9 gene on disease outcomes, including neurological and neuropsychiatric disease.
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Emerging role of HDL in brain cholesterol metabolism and neurodegenerative disorders. Biochim Biophys Acta Mol Cell Biol Lipids 2022; 1867:159123. [PMID: 35151900 DOI: 10.1016/j.bbalip.2022.159123] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 02/01/2022] [Accepted: 02/03/2022] [Indexed: 01/07/2023]
Abstract
High-density lipoproteins (HDLs play a key role in cholesterol homeostasis maintenance in the central nervous system (CNS), by carrying newly synthesized cholesterol from astrocytes to neurons, to support their lipid-related physiological functions. As occurs for plasma HDLs, brain lipoproteins are assembled through the activity of membrane cholesterol transporters, undergo remodeling mediated by specific enzymes and transport proteins, and finally deliver cholesterol to neurons by a receptor-mediated internalization process. A growing number of evidences indicates a strong association between alterations of CNS cholesterol homeostasis and neurodegenerative disorders, in particular Alzheimer's disease (AD), and a possible role in this relationship may be played by defects in brain HDL metabolism. In the present review, we summarize and critically examine the current state of knowledge on major modifications of HDL and HDL-mediated brain cholesterol transport in AD, by taking into consideration the individual steps of this process. We also describe potential and encouraging HDL-based therapies that could represent new therapeutic strategies for AD treatment. Finally, we revise the main plasma and brain HDL modifications in other neurodegenerative disorders including Parkinson's disease (PD), Huntington's disease (HD), and frontotemporal dementia (FTD).
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Cuchillo-Ibañez I, Lennol MP, Escamilla S, Mata-Balaguer T, Valverde-Vozmediano L, Lopez-Font I, Ferrer I, Sáez-Valero J. The apolipoprotein receptor LRP3 compromises APP levels. Alzheimers Res Ther 2021; 13:181. [PMID: 34727970 PMCID: PMC8565065 DOI: 10.1186/s13195-021-00921-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 10/19/2021] [Indexed: 11/16/2022]
Abstract
BACKGROUND Members of the low-density lipoprotein (LDL) receptor family are involved in endocytosis and in transducing signals, but also in amyloid precursor protein (APP) processing and β-amyloid secretion. ApoER2/LRP8 is a member of this family with key roles in synaptic plasticity in the adult brain. ApoER2 is cleaved after the binding of its ligand, the reelin protein, generating an intracellular domain (ApoER2-ICD) that modulates reelin gene transcription itself. We have analyzed whether ApoER2-ICD is able to regulate the expression of other LDL receptors, and we focused on LRP3, the most unknown member of this family. We analyzed LRP3 expression in middle-aged individuals (MA) and in cases with Alzheimer's disease (AD)-related pathology, and the relation of LRP3 with APP. METHODS The effects of full-length ApoER2 and ApoER2-ICD overexpression on protein levels, in the presence of recombinant reelin or Aβ42 peptide, were evaluated by microarray, qRT-PCRs, and western blots in SH-SY5Y cells. LRP3 expression was analyzed in human frontal cortex extracts from MA subjects (mean age 51.8±4.8 years) and AD-related pathology subjects [Braak neurofibrillary tangle stages I-II, 68.4±8.8 years; III-IV, 80.4 ± 8.8 years; V-VI, 76.5±9.7 years] by qRT-PCRs and western blot; LRP3 interaction with other proteins was assessed by immunoprecipitation. In CHO cells overexpressing LRP3, protein levels of full-length APP and fragments were evaluated by western blots. Chloroquine was employed to block the lysosomal/autophagy function. RESULTS We have identified that ApoER2 overexpression increases LRP3 expression, also after reelin stimulation of ApoER2 signaling. The same occurred following ApoER2-ICD overexpression. In extracts from subjects with AD-related pathology, the levels of LRP3 mRNA and protein were lower than those in MA subjects. Interestingly, LRP3 transfection in CHO-PS70 cells induced a decrease of full-length APP levels and APP-CTF, particularly in the membrane fraction. In cell supernatants, levels of APP fragments from the amyloidogenic (sAPPα) or non-amyloidogenic (sAPPβ) pathways, as well as Aβ peptides, were drastically reduced with respect to mock-transfected cells. The inhibitor of lysosomal/autophagy function, chloroquine, significantly increased full-length APP, APP-CTF, and sAPPα levels. CONCLUSIONS ApoER2/reelin signaling regulates LRP3 expression, whose levels are affected in AD; LRP3 is involved in the regulation of APP levels.
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Affiliation(s)
- Inmaculada Cuchillo-Ibañez
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández de Elche-CSIC, Sant Joan d'Alacant, Spain.
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.
- Instituto de Investigación Sanitaria y Biomédica de Alicante (ISABIAL), Alicante, Spain.
| | - Matthew P Lennol
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández de Elche-CSIC, Sant Joan d'Alacant, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Sergio Escamilla
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández de Elche-CSIC, Sant Joan d'Alacant, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Trinidad Mata-Balaguer
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández de Elche-CSIC, Sant Joan d'Alacant, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Lucía Valverde-Vozmediano
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández de Elche-CSIC, Sant Joan d'Alacant, Spain
| | - Inmaculada Lopez-Font
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández de Elche-CSIC, Sant Joan d'Alacant, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
- Instituto de Investigación Sanitaria y Biomédica de Alicante (ISABIAL), Alicante, Spain
| | - Isidro Ferrer
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
- Instituto de Neuropatología, Hospital Universitario de Bellvitge, Universidad de Barcelona, Hospitalet de Llobregat, Barcelona, Spain
| | - Javier Sáez-Valero
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández de Elche-CSIC, Sant Joan d'Alacant, Spain.
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.
- Instituto de Investigación Sanitaria y Biomédica de Alicante (ISABIAL), Alicante, Spain.
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O'Connell EM, Lohoff FW. Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9) in the Brain and Relevance for Neuropsychiatric Disorders. Front Neurosci 2020; 14:609. [PMID: 32595449 PMCID: PMC7303295 DOI: 10.3389/fnins.2020.00609] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 05/18/2020] [Indexed: 12/11/2022] Open
Abstract
Proprotein convertase subtilisin/kexin type 9 (PCSK9) has long been studied in the liver due to its regulation of plasma low-density lipoprotein cholesterol (LDL-C) and its causal role in familial hypercholesterolemia. Although PCSK9 was first discovered in cerebellar neurons undergoing apoptosis, its function in the central nervous system (CNS) is less clear. PCSK9 has been shown to be involved in neuronal differentiation, LDL receptor family metabolism, apoptosis, and inflammation in the brain, but in vitro and in vivo studies offer contradictory findings. PCSK9 expression in the adult brain is low but is highly upregulated during disease states. Cerebral spinal fluid (CSF) PCSK9 concentrations are correlated with neural tube defects and neurodegenerative diseases in human patients. Epigenetic studies reveal that chronic alcohol use may modulate methylation of the PCSK9 gene and genetic studies show that patients with gain-of-function PCSK9 variants have higher LDL-C and an increased risk of ischemic stroke. Early safety studies of the PCSK9 inhibitors evolocumab and alirocumab, used to treat hypercholesterolemia, hinted that PCSK9 inhibition may negatively impact cognition but more recent, longer-term clinical trials found no adverse neurocognitive events. The purpose of this review is to elucidate the role of PCSK9 in the brain, particularly its role in disease pathogenesis.
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Affiliation(s)
- Emma M O'Connell
- Section on Clinical Genomics and Experimental Therapeutics, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, United States
| | - Falk W Lohoff
- Section on Clinical Genomics and Experimental Therapeutics, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, United States
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The Reelin Receptors Apolipoprotein E receptor 2 (ApoER2) and VLDL Receptor. Int J Mol Sci 2018; 19:ijms19103090. [PMID: 30304853 PMCID: PMC6213145 DOI: 10.3390/ijms19103090] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 10/03/2018] [Accepted: 10/03/2018] [Indexed: 01/28/2023] Open
Abstract
Apolipoprotein E receptor 2 (ApoER2) and VLDL receptor belong to the low density lipoprotein receptor family and bind apolipoprotein E. These receptors interact with the clathrin machinery to mediate endocytosis of macromolecules but also interact with other adapter proteins to perform as signal transduction receptors. The best characterized signaling pathway in which ApoER2 and VLDL receptor (VLDLR) are involved is the Reelin pathway. This pathway plays a pivotal role in the development of laminated structures of the brain and in synaptic plasticity of the adult brain. Since Reelin and apolipoprotein E, are ligands of ApoER2 and VLDLR, these receptors are of interest with respect to Alzheimer’s disease. We will focus this review on the complex structure of ApoER2 and VLDLR and a recently characterized ligand, namely clusterin.
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Genome-wide DNA methylation profiles reveal novel candidate genes associated with meat quality at different age stages in hens. Sci Rep 2017; 7:45564. [PMID: 28378745 PMCID: PMC5381223 DOI: 10.1038/srep45564] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 02/27/2017] [Indexed: 01/18/2023] Open
Abstract
Poultry meat quality is associated with breed, age, tissue and other factors. Many previous studies have focused on distinct breeds; however, little is known regarding the epigenetic regulatory mechanisms in different age stages, such as DNA methylation. Here, we compared the global DNA methylation profiles between juvenile (20 weeks old) and later laying-period (55 weeks old) hens and identified candidate genes related to the development and meat quality of breast muscle using whole-genome bisulfite sequencing. The results showed that the later laying-period hens, which had a higher intramuscular fat (IMF) deposition capacity and water holding capacity (WHC) and less tenderness, exhibited higher global DNA methylation levels than the juvenile hens. A total of 2,714 differentially methylated regions were identified in the present study, which corresponded to 378 differentially methylated genes, mainly affecting muscle development, lipid metabolism, and the ageing process. Hypermethylation of the promoters of the genes ABCA1, COL6A1 and GSTT1L and the resulting transcriptional down-regulation in the later laying-period hens may be the reason for the significant difference in the meat quality between the juvenile and later laying-period hens. These findings contribute to a better understanding of epigenetic regulation in the skeletal muscle development and meat quality of chicken.
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Pohlkamp T, Wasser CR, Herz J. Functional Roles of the Interaction of APP and Lipoprotein Receptors. Front Mol Neurosci 2017; 10:54. [PMID: 28298885 PMCID: PMC5331069 DOI: 10.3389/fnmol.2017.00054] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 02/16/2017] [Indexed: 11/24/2022] Open
Abstract
The biological fates of the key initiator of Alzheimer’s disease (AD), the amyloid precursor protein (APP), and a family of lipoprotein receptors, the low-density lipoprotein (LDL) receptor-related proteins (LRPs) and their molecular roles in the neurodegenerative disease process are inseparably interwoven. Not only does APP bind tightly to the extracellular domains (ECDs) of several members of the LRP group, their intracellular portions are also connected through scaffolds like the one established by FE65 proteins and through interactions with adaptor proteins such as X11/Mint and Dab1. Moreover, the ECDs of APP and LRPs share common ligands, most notably Reelin, a regulator of neuronal migration during embryonic development and modulator of synaptic transmission in the adult brain, and Agrin, another signaling protein which is essential for the formation and maintenance of the neuromuscular junction (NMJ) and which likely also has critical, though at this time less well defined, roles for the regulation of central synapses. Furthermore, the major independent risk factors for AD, Apolipoprotein (Apo) E and ApoJ/Clusterin, are lipoprotein ligands for LRPs. Receptors and ligands mutually influence their intracellular trafficking and thereby the functions and abilities of neurons and the blood-brain-barrier to turn over and remove the pathological product of APP, the amyloid-β peptide. This article will review and summarize the molecular mechanisms that are shared by APP and LRPs and discuss their relative contributions to AD.
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Affiliation(s)
- Theresa Pohlkamp
- Department of Molecular Genetics, UT Southwestern Medical CenterDallas, TX, USA; Center for Translational Neurodegeneration Research, UT Southwestern Medical CenterDallas, TX, USA
| | - Catherine R Wasser
- Department of Molecular Genetics, UT Southwestern Medical CenterDallas, TX, USA; Center for Translational Neurodegeneration Research, UT Southwestern Medical CenterDallas, TX, USA
| | - Joachim Herz
- Department of Molecular Genetics, UT Southwestern Medical CenterDallas, TX, USA; Center for Translational Neurodegeneration Research, UT Southwestern Medical CenterDallas, TX, USA; Department of Neuroscience, UT Southwestern Medical CenterDallas, TX, USA; Department of Neurology and Neurotherapeutics, UT Southwestern Medical CenterDallas, TX, USA
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13
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Cuchillo-Ibañez I, Balmaceda V, Mata-Balaguer T, Lopez-Font I, Sáez-Valero J. Reelin in Alzheimer’s Disease, Increased Levels but Impaired Signaling: When More is Less. J Alzheimers Dis 2016; 52:403-16. [DOI: 10.3233/jad-151193] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Inmaculada Cuchillo-Ibañez
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Sant Joan d’Alacant, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Valeria Balmaceda
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Sant Joan d’Alacant, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Trinidad Mata-Balaguer
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Sant Joan d’Alacant, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Inmaculada Lopez-Font
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Sant Joan d’Alacant, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Javier Sáez-Valero
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Sant Joan d’Alacant, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
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14
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Zhang J, Zhang X, Zhang L, Zhou F, van Dinther M, Ten Dijke P. LRP8 mediates Wnt/β-catenin signaling and controls osteoblast differentiation. J Bone Miner Res 2012; 27:2065-74. [PMID: 22589174 DOI: 10.1002/jbmr.1661] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The Wnt/β-catenin signaling pathway plays a pivotal role in regulating osteoblast differentiation and bone formation. Here, we identify low-density lipoprotein (LDL) receptor-related protein 8 (LRP8) as a positive regulator of Wnt/β-catenin signaling. In a small interfering RNA (siRNA) screen, LRP8 was shown to be required for Wnt/β-catenin-induced transcriptional reporter activity. We found that ectopic expression of LRP8 increased Wnt-induced transcriptional responses, and promoted Wnt-induced β-catenin accumulation. Moreover, knockdown of LRP8 resulted in a decrease in β-catenin levels and suppression of Wnt/β-catenin-induced Axin2 transcription. Functional studies in KS483 osteoprogenitor cells showed that LRP8 depletion resulted in impaired activation of endogenous Wnt-induced genes and decreased osteoblast differentiation and mineralization, whereas LRP8 ectopic expression had the opposite effect. These results identify LRP8 as a novel positive factor of canonical Wnt signaling pathway and show its involvement in Wnt-induced osteoblast differentiation.
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Affiliation(s)
- Juan Zhang
- Department of Molecular Cell Biology and Center for Biomedical Genetics, Leiden University Medical Center, Leiden, The Netherlands
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15
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Herskowitz JH, Offe K, Deshpande A, Kahn RA, Levey AI, Lah JJ. GGA1-mediated endocytic traffic of LR11/SorLA alters APP intracellular distribution and amyloid-β production. Mol Biol Cell 2012; 23:2645-57. [PMID: 22621900 PMCID: PMC3395654 DOI: 10.1091/mbc.e12-01-0014] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Defining the cellular pathway(s) by which LR11 modulates amyloid-β peptide production is critical to understanding how changes in LR11 expression affect the progression of Alzheimer's disease. These results suggest that endocytic traffic of LR11, facilitated by GGA1, enhances LR11 modulation of amyloid precursor protein processing in a nonamyloidogenic manner. Proteolytic processing of the amyloid-β precursor protein (APP) and generation of amyloid-β peptide (Aβ) are key events in Alzheimer's disease (AD) pathogenesis. Cell biological and genetic evidence has implicated the low-density lipoprotein and sorting receptor LR11/SorLA in AD through mechanisms related to APP and Aβ production. Defining the cellular pathway(s) by which LR11 modulates Aβ production is critical to understanding how changes in LR11 expression affect the development of Aβ pathology in AD progression. We report that the LR11 ectodomain is required for LR11-mediated reduction of Aβ and that mutagenesis of the LR11 Golgi-localizing, γ-adaptin ear homology domain, ADP-ribosylation factor (GGA)-binding motif affects the endosomal distribution of LR11, as well as LR11's effects on APP traffic and Aβ production. Targeted small interfering RNA (siRNA) knockdown studies of GGA1, GGA2, and GGA3 indicate a surprising degree of specificity toward GGA1, suggesting that GGA1 is a candidate regulator of LR11 traffic. Additional siRNA knockdown experiments reveal that GGA1 is necessary for both LR11 and β-site APP-cleaving enzyme-1 (BACE1) modulation of APP processing to Aβ. Mutagenesis of BACE1 serine 498 to alanine enhances BACE1 targeting to LR11-positive compartments and nullifies LR11-mediated reduction of Aβ. On basis of these results, we propose that GGA1 facilitates LR11 endocytic traffic and that LR11 modulates Aβ levels by promoting APP traffic to the endocytic recycling compartment.
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Affiliation(s)
- Jeremy H Herskowitz
- Center for Neurodegenerative Disease, Department of Neurology, Emory University School of Medicine, Atlanta, GA 30322, USA
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16
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Toward an Alzheimer's disease diagnosis via high‐resolution blood gene expression. Alzheimers Dement 2010; 6:25-38. [DOI: 10.1016/j.jalz.2009.07.001] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2008] [Revised: 07/02/2009] [Accepted: 07/02/2009] [Indexed: 11/21/2022]
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17
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Marzolo MP, Bu G. Lipoprotein receptors and cholesterol in APP trafficking and proteolytic processing, implications for Alzheimer's disease. Semin Cell Dev Biol 2008; 20:191-200. [PMID: 19041409 DOI: 10.1016/j.semcdb.2008.10.005] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2008] [Accepted: 10/13/2008] [Indexed: 12/30/2022]
Abstract
Amyloid-beta (Abeta) peptide accumulation in the brain is central to the pathogenesis of Alzheimer's disease (AD). Abeta is produced through proteolytic processing of a transmembrane protein, beta-amyloid precursor protein (APP), by beta- and gamma-secretases. Mounting evidence has demonstrated that alterations in APP cellular trafficking and localization directly impact its processing to Abeta. Members of the low-density lipoprotein receptor family, including LRP, LRP1B, SorLA/LR11, and apoER2, interact with APP and regulate its endocytic trafficking. Additionally, APP trafficking and processing are greatly affected by cellular cholesterol content. In this review, we summarize the current understanding of the roles of lipoprotein receptors and cholesterol in APP trafficking and processing and their implication for AD pathogenesis and therapy.
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Affiliation(s)
- Maria-Paz Marzolo
- FONDAP Center for Cell Regulation and Pathology (CRCP), Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile and MIFAB, Santiago, Chile
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18
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Abstract
The antiphospholipid syndrome is a non-inflammatory autoimmune disease characterised by the presence of antiphospholipid antibodies in the plasma of patients with venous or arterial thrombosis or recurrent complications of pregnancy. The strong relation between the presence of antibodies against anionic phospholipids and thrombo-embolic complications is well established, but how the presence of antiphospholipid antibodies results in the observed clinical manifestations remains a mystery. Experimental observations suggest that an altered regulation of platelet function can cause the thrombotic complications observed in the antiphospholipid syndrome. In this review, we will discuss the evidence that the platelet is an important player in the pathogenesis of the antiphospholipid syndrome.
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Affiliation(s)
- RT Urbanus
- Department of Clinical Chemistry and Haematology, University Medical Center, Utrecht, the Netherlands
| | - RHWM Derksen
- Department of Rheumatology and Clinical Immunology, University Medical Center, Utrecht, the Netherlands
| | - PG de Groot
- Department of Clinical Chemistry and Haematology, University Medical Center, Utrecht, the Netherlands
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19
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Abstract
The antiphospholipid antibody syndrome (APS) is characterized by recurrent arterial and venous thrombosis and/or pregnancy in association with antiphospholipid (aPL) antibodies. The pathogenic mechanisms in APS that lead to in vivo injury are incompletely understood. Recent evidence suggests that APL antibodies alter regulation of haemostasis and induce activation of complement. We will discuss the current knowledge on how aPL antibodies trigger increased inflammation and enhanced thrombotic tendency, and thereby lead to tissue damage.
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Affiliation(s)
- J E Salmon
- Department of Medicine, Hospital for Special Surgery, Weill Medical College of Cornell University, New York, New York 10021, USA.
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20
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Helbecque N, Cottel D, Amouyel P. Low-density lipoprotein receptor-related protein 8 gene polymorphisms and dementia. Neurobiol Aging 2007; 30:266-71. [PMID: 17614163 DOI: 10.1016/j.neurobiolaging.2007.05.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2006] [Revised: 03/20/2007] [Accepted: 05/29/2007] [Indexed: 12/23/2022]
Abstract
The sole known genetic risk factor for sporadic Alzheimer's disease (AD) is the gene encoding apolipoprotein E (APOE), but the underlying mechanism is still under debate. One hypothesis relies on an interaction between APOE and its receptors. Previous studies have shown association of LDL receptor-related protein (LRP1) with AD and we previously reported a modulation by LRP1 of the risk of AD conferred by the -499A>G promoter polymorphism of the MAPK8IP1, a gene encoding Islet-brain-1 (IB1), the human counterpart of c-Jun NH(2) terminal kinase interacting protein-1 (JIP-1). Here we tested in two independent population samples a possible impact of another receptor for APOE, namely the low-density lipoprotein receptor-related protein 8 (LRP8), on the risk of dementia. Our results did not reveal any direct impact of a LRP8 coding (Arg952Gln) mutation on the risk of AD. However, this polymorphism increased the risk of AD conferred by the MAPK8IP1 G allele.
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21
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Menéndez-González M, Pérez-Pinera P, Martínez-Rivera M, Calatayud MT, Blázquez Menes B. APP processing and the APP-KPI domain involvement in the amyloid cascade. NEURODEGENER DIS 2006; 2:277-83. [PMID: 16909010 DOI: 10.1159/000092315] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2005] [Accepted: 12/08/2005] [Indexed: 12/21/2022] Open
Abstract
Alternative APP mRNA splicing can generate isoforms of APP containing a Kunitz protease inhibitor (KPI) domain. KPI is one of the main serine protease inhibitors. Protein and mRNA KPI(+)APP levels are elevated in Alzheimer's disease (AD) brain and are associated with increased amyloid beta deposition. In the last years increasing evidence on multiple points in the amyloid cascade where KPI(+)APP is involved has been accumulated, admitting an outstanding position in the pathogenesis of AD to the KPI domain. This review focuses on the APP processing, the molecular activity of KPI and its physiological and pathological roles and the KPI involvement in the amyloid cascade through the nerve growth factor, the lipoprotein receptor-related protein, the tumor necrosis factor-alpha converting enzyme and the Notch1 protein.
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Affiliation(s)
- M Menéndez-González
- Neurology Department, Hospital Universitario Central de Asturias, Oviedo, Spain.
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22
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Thilakawardhana S, Everett DM, Murdock PR, Dingwall C, Owen JS. Quantification of apolipoprotein E receptors in human brain-derived cell lines by real-time polymerase chain reaction. Neurobiol Aging 2005; 26:813-23. [PMID: 15718039 DOI: 10.1016/j.neurobiolaging.2004.08.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2004] [Revised: 07/27/2004] [Accepted: 08/04/2004] [Indexed: 11/18/2022]
Abstract
Apolipoprotein (apo) E4 is a risk factor for Alzheimer's disease (AD) and other neurodegenerative diseases, compared to wild-type apoE3. The mechanism(s) is unknown. One possibility, demonstrated in peripheral tissue cell lines, is that apoE stimulates nitric oxide synthase (NOS) via a receptor-dependent signalling pathway and that apoE4 generates inappropriate amounts of nitric oxide (NO) compared to apoE3. Prior to biochemical investigations, we have quantified the expression of several candidate receptor genes, including low-density lipoprotein-receptor (LDL-r) family members and scavenger receptor class B, types I and II (SR-BI/II), as well as the three NOS isoenzymes and protein kinase B (Akt), in 38 human cell lines, of which 12 derive from brain. Expression of apoE receptor 2 (apoER2), a known signalling receptor in brain, was readily detected in SH-SY-5Y and CCF-STTG1 cells, common models of neurons and astrocytes, respectively, and was highest in H4 neuroglioma, NT-2 precursor cells and IMR-32 neuroblastoma cells. Transcripts of the other lipoprotein receptors were widely, but variably, distributed across the different cell types. Of particular note was the predominant expression of SR-BII over SR-BI in many of the brain-derived cells. As the C-terminus of SR-BII, like apoER2, contains potential SH3 signalling motifs, we suggest that in brain SR-BII functions as a signal transducer receptor.
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Affiliation(s)
- Shanaka Thilakawardhana
- Department of Medicine, Royal Free and University College Medical School, Royal Free Campus, University College London, London NW3 2PF, UK
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23
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Motoi Y, Itaya M, Mori H, Mizuno Y, Iwasaki T, Hattori H, Haga S, Ikeda K. Apolipoprotein E receptor 2 is involved in neuritic plaque formation in APP sw mice. Neurosci Lett 2004; 368:144-7. [PMID: 15351437 DOI: 10.1016/j.neulet.2004.06.081] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2004] [Revised: 06/15/2004] [Accepted: 06/29/2004] [Indexed: 11/22/2022]
Abstract
Apolipoprotein E receptor 2 (apoER2) is a receptor for apolipoprotein E containing lipoprotein and also for Reelin. Apolipoprotein E-associated risk of developing Alzheimer's disease (AD) may be related to its binding to and clearance by cell surface receptors, including members of the low-density lipoprotein receptor family. Otherwise there is circumstantial evidence that the Reelin signaling pathway may contribute to neurodegeneration in AD. To investigate the role of apoER2 on amyloid deposition and neurodegeneration in vivo, we examined the presence of apoER2 in the brains of APP sw transgenic mice (Tg2576) using three apoER2 monoclonal antibodies. Our immunohistochemical study revealed that apoER2 was localized in fine granular structure and reactive astrocytes surrounding amyloid plaques. The double labeling immunohistochemistry revealed that this granular structure overlaps synaptophysin-positive dystrophic neurites. These findings indicate that neuronal apoER2 may play a role for amyloid deposition and neuronal degeneration in AD.
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Affiliation(s)
- Yumiko Motoi
- Department of Neurology, Juntendo University School of Medicine, 3-1-3 Hongo Bunkyo-ku, Tokyo 113-8431, Japan.
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24
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Korporaal SJA, Relou IAM, van Eck M, Strasser V, Bezemer M, Gorter G, van Berkel TJC, Nimpf J, Akkerman JWN, Lenting PJ. Binding of low density lipoprotein to platelet apolipoprotein E receptor 2' results in phosphorylation of p38MAPK. J Biol Chem 2004; 279:52526-34. [PMID: 15459198 DOI: 10.1074/jbc.m407407200] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Binding of low density lipoprotein (LDL) to platelets enhances platelet responsiveness to various aggregation-inducing agents. However, the identity of the platelet surface receptor for LDL is unknown. We have previously reported that binding of the LDL component apolipoprotein B100 to platelets induces rapid phosphorylation of p38 mitogen-activated protein kinase (p38MAPK). Here, we show that LDL-dependent activation of this kinase is inhibited by receptor-associated protein (RAP), an inhibitor of members of the LDL receptor family. Confocal microscopy revealed a high degree of co-localization of LDL and a splice variant of the LDL receptor family member apolipoprotein E receptor-2 (apoER2') at the platelet surface, suggesting that apoER2' may contribute to LDL-induced platelet signaling. Indeed, LDL was unable to induce p38MAPK activation in platelets of apoER2-deficient mice. Furthermore, LDL bound efficiently to soluble apoER2', and the transient LDL-induced activation of p38MAPK was mimicked by an anti-apoER2 antibody. Association of LDL to platelets resulted in tyrosine phosphorylation of apoER2', a process that was inhibited in the presence of PP1, an inhibitor of Src-like tyrosine kinases. Moreover, phosphorylated but not native apoER2' co-precipitated with the Src family member Fgr. This suggests that exposure of platelets to LDL induces association of apoER2' to Fgr, a kinase that is able to activate p38MAPK. In conclusion, our data indicate that apoER2' contributes to LDL-dependent sensitization of platelets.
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MESH Headings
- Animals
- Binding Sites
- Blood Platelets/metabolism
- Cell Membrane/metabolism
- Enzyme Activation
- In Vitro Techniques
- Lipoproteins, LDL/blood
- Low Density Lipoprotein Receptor-Related Protein-1/blood
- Low Density Lipoprotein Receptor-Related Protein-1/chemistry
- Membrane Proteins/deficiency
- Membrane Proteins/genetics
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Phosphorylation
- Protein Binding
- Receptors, Immunologic/deficiency
- Receptors, Immunologic/genetics
- Receptors, LDL/deficiency
- Receptors, LDL/genetics
- Receptors, Lipoprotein/deficiency
- Receptors, Lipoprotein/genetics
- Receptors, Scavenger
- Scavenger Receptors, Class B
- Signal Transduction
- Tyrosine/chemistry
- p38 Mitogen-Activated Protein Kinases/blood
- src-Family Kinases/blood
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Affiliation(s)
- Suzanne J A Korporaal
- Laboratory for Thrombosis and Haemostasis, Department of Haematology, University Medical Center Utrecht and Institute of Biomembranes, University of Utrecht, Heidelberglaan 100, 3584 CX Utrecht, the Netherlands
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25
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Guo J, Chen S, Huang C, Chen L, Studholme DJ, Zhao S, Yu L. MANSC: a seven-cysteine-containing domain present in animal membrane and extracellular proteins. Trends Biochem Sci 2004; 29:172-4. [PMID: 15124631 DOI: 10.1016/j.tibs.2004.02.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Jinhu Guo
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Handan Road 220, Shanghai 200-433, China
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26
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Chen ZJ, Vulevic B, Ile KE, Soulika A, Davis W, Reiner PB, Connop BP, Nathwani P, Trojanowski JQ, Tew KD. Association of ABCA2 expression with determinants of Alzheimer's disease. FASEB J 2004; 18:1129-31. [PMID: 15155565 DOI: 10.1096/fj.03-1490fje] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
With the use of a novel method for detecting differential gene expression, alterations in functional gene clusters related to transport or oxidative stress response and beta-amyloid (Abeta) peptide metabolism were identified in a HEK293 cell line engineered to overexpress the human ATP binding cassette transporter ABCA2. These included fatty acid binding protein, phospholipid binding protein, phospholipid synthesis protein, transporter cofactors, seladin-1, Abeta precursor protein (APP), vimentin, and low-density lipoprotein receptor-related protein. ABCA2 was highly expressed in neuroblastoma cells and colocalized with Abeta and APP. Additionally, increased APP protein levels were detected within ABCA2/APP double-transfected cells, and increased Abeta was detected in the media of ABCA2-transfected cells relative to controls. The transporter was abundant in the temporal and frontal regions of both normal and Alzheimer's disease (AD) brain but was detected at lower concentrations in the parietal, occipital, and cerebellar regions. The ABCA2 transfected cell line expressed resistance to a free radical initiator, confirming involvement in protection against reactive oxygen species and suggesting a further possible link to AD.
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Affiliation(s)
- Zhijian J Chen
- Department of Pharmacology, Fox Chase Cancer Center, Philadelphia, Pennsylvania, USA
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27
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Abstract
PURPOSE OF REVIEW Numerous epidemiological and clinical data suggest that neurodegenerative disorders, such as Alzheimer's disease, may be related directly or indirectly to cardiovascular risk. Genetic studies have demonstrated that they share at least one common susceptibility gene, encoding apolipoprotein E, a modulator of cardiac risk and of cognitive impairment. Several studies have suggested that other genes involved in the development of cardiovascular diseases may be involved. Previous studies indicated that additional genes contribute to Alzheimer's disease, in particular to the sporadic, more common late-onset form. In this review, the authors focus on recent findings concerning the modulation of the risk of Alzheimer's disease by genes also involved in the development of cardiovascular diseases. RECENT FINDINGS The intensive search conducted in the past year gave rise to many publications, more than half of which were related to genes common to cardiovascular and neurodegenerative disorders. The majority of the genes studied are involved in cholesterol metabolism, hypertension, lipid oxidation and detoxication, or inflammatory processes. SUMMARY In the past year, approximately 100 studies concerning the genetics of Alzheimer's disease were published around the world. Results suggest that the risk of Alzheimer's disease is modulated by various genes encoding proteins involved in cholesterol metabolism, in the detoxication of lipoprotein oxidation or encoding cytokines.
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Affiliation(s)
- Nicole Helbecque
- Service d'Epidémiologie et de Santé Publique, INSERM U508, Institut Pasteur de Lille, France
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