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Fukui T, Yabumoto M, Nishida M, Hirokawa S, Sato R, Kurisu T, Nakai M, Hassan MA, Kishimoto K. Amino acid deprivation in cancer cells with compensatory autophagy induction increases sensitivity to autophagy inhibitors. Mol Cell Oncol 2024; 11:2377404. [PMID: 39021618 PMCID: PMC11253891 DOI: 10.1080/23723556.2024.2377404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Accepted: 07/03/2024] [Indexed: 07/20/2024]
Abstract
Inhibition of autophagy is an important strategy in cancer therapy. However, prolonged inhibition of certain autophagies in established cancer cells may increase therapeutic resistance, though the underlying mechanisms of its induction and enhancement remain unclear. This study sought to elucidate the mechanisms of therapeutic resistance through repeated autophagy inhibition and amino acid deprivation (AD) in an in vitro model of in vivo chronic nutrient deprivation associated with cancer cell treatment. In the human cervical cancer cell line HeLa and human breast cancer cell line MCF-7, initial extracellular AD induced the immediate expression of endosomal microautophagy (eMI). However, repeated inhibition of eMI with U18666A and extracellular AD induced macroautophagy (MA) to compensate for reduced eMI, simultaneously decreasing cytotoxicity. Here, hyperphosphorylated JNK was transformed into a hypophosphorylated state, suggesting conversion of the cell death signal to a survival signal. In a nutrient medium, cell death could not be induced by MA inhibition. However, since LAT1 inhibitors induce intracellular AD, combining them with MA and eMI inhibitors successfully promoted cell death in resistant cells. Our study identified a novel therapeuic approach for promoting cell death and addressing therapeutic resistance in cancers under autophagy-inhibitor treatment.
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Affiliation(s)
- Takahito Fukui
- Division of Bioscience and Bioindustry, Tokushima University Graduate School of Sciences and Technology for Innovation, Tokushima, Japan
| | - Manami Yabumoto
- Division of Bioscience and Bioindustry, Tokushima University Graduate School of Sciences and Technology for Innovation, Tokushima, Japan
| | - Misuzu Nishida
- Division of Bioscience and Bioindustry, Tokushima University Graduate School of Sciences and Technology for Innovation, Tokushima, Japan
| | - Shiori Hirokawa
- Graduate School of Environment and Energy Engineering, Waseda University, Tokyo, Japan
| | - Riho Sato
- Graduate School of Medical Life Science, Yokohama City University, Yokohama, Japan
| | - Taichi Kurisu
- Division of Bioscience and Bioindustry, Tokushima University Graduate School of Sciences and Technology for Innovation, Tokushima, Japan
| | - Miyu Nakai
- Division of Bioscience and Bioindustry, Tokushima University Graduate School of Sciences and Technology for Innovation, Tokushima, Japan
| | - Md. Abul Hassan
- Faculty of Bioscience and Bioindustry, Tokushima University Graduate School of Advanced Technology and Science, Tokushima, Japan
| | - Koji Kishimoto
- Division of Bioscience and Bioindustry, Tokushima University Graduate School of Technology, Industrial and Social Sciences, Tokushima, Japan
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Ali FEM, Abdel-Reheim MA, Hassanein EHM, Abd El-Aziz MK, Althagafy HS, Badran KSA. Exploring the potential of drug repurposing for liver diseases: A comprehensive study. Life Sci 2024; 347:122642. [PMID: 38641047 DOI: 10.1016/j.lfs.2024.122642] [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: 02/09/2024] [Revised: 03/24/2024] [Accepted: 04/10/2024] [Indexed: 04/21/2024]
Abstract
Drug repurposing involves the investigation of existing drugs for new indications. It offers a great opportunity to quickly identify a new drug candidate at a lower cost than novel discovery and development. Despite the importance and potential role of drug repurposing, there is no specific definition that healthcare providers and the World Health Organization credit. Unfortunately, many similar and interchangeable concepts are being used in the literature, making it difficult to collect and analyze uniform data on repurposed drugs. This research was conducted based on understanding general criteria for drug repurposing, concentrating on liver diseases. Many drugs have been investigated for their effect on liver diseases even though they were originally approved (or on their way to being approved) for other diseases. Some of the hypotheses for drug repurposing were first captured from the literature and then processed further to test the hypothesis. Recently, with the revolution in bioinformatics techniques, scientists have started to use drug libraries and computer systems that can analyze hundreds of drugs to give a short list of candidates to be analyzed pharmacologically. However, this study revealed that drug repurposing is a potential aid that may help deal with liver diseases. It provides available or under-investigated drugs that could help treat hepatitis, liver cirrhosis, Wilson disease, liver cancer, and fatty liver. However, many further studies are needed to ensure the efficacy of these drugs on a large scale.
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Affiliation(s)
- Fares E M Ali
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Al-Azhar University, Assiut 71524, Egypt; Michael Sayegh, Faculty of Pharmacy, Aqaba University of Technology, Aqaba 77110, Jordan
| | - Mustafa Ahmed Abdel-Reheim
- Department of Pharmaceutical Sciences, College of Pharmacy, Shaqra University, Shaqra 11961, Saudi Arabia; Department of Pharmacology and Toxicology, Faculty of Pharmacy, Beni-Suef University, Beni Suef 62521, Egypt.
| | - Emad H M Hassanein
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Al-Azhar University, Assiut 71524, Egypt.
| | - Mostafa K Abd El-Aziz
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Al-Azhar University, Assiut 71524, Egypt
| | - Hanan S Althagafy
- Department of Biochemistry, Faculty of Science, University of Jeddah, Jeddah, Saudi Arabia
| | - Khalid S A Badran
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Al-Azhar University, Assiut 71524, Egypt
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Yasamineh S, Mehrabani FJ, Derafsh E, Danihiel Cosimi R, Forood AMK, Soltani S, Hadi M, Gholizadeh O. Potential Use of the Cholesterol Transfer Inhibitor U18666A as a Potent Research Tool for the Study of Cholesterol Mechanisms in Neurodegenerative Disorders. Mol Neurobiol 2024; 61:3503-3527. [PMID: 37995080 DOI: 10.1007/s12035-023-03798-7] [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: 04/11/2023] [Accepted: 11/03/2023] [Indexed: 11/24/2023]
Abstract
Cholesterol is an essential component of mammalian cell membranes and a precursor for crucial signaling molecules. The brain contains the highest level of cholesterol in the body, and abnormal cholesterol metabolism links to many neurodegenerative disorders. The results indicate that faulty cholesterol metabolism is a common feature among people living with neurodegenerative conditions. The researchers suggest that restoring cholesterol levels may become a beneficial new strategy in treating certain neurodegenerative conditions. Several neurodegenerative disorders, such as Alzheimer's disease (AD), Niemann-Pick type C (NPC) disease, and Parkinson's disease (PD), have been connected to abnormalities in brain cholesterol metabolism. Consequently, using a lipid research tool is vital to study further and understand the effect of lipids in neurodegenerative disorders such as NPC, AD, PD, and Huntington's disease (HD). U18666A, also known as 3-(2-(diethylamino) ethoxy) androst-5-en-17-one, is a pharmaceutical drug that suppresses cholesterol trafficking and is a well-known class-2 amphiphile. U18666A has performed many functions, allowing for essential discoveries in lipid studies and shedding light on the pathophysiology of neurodegenerative disorders. Additionally, U18666A prevented the downregulation of low-density lipoprotein (LDL) receptors that are induced by LDL and led to the buildup of cholesterol in lysosomes. Numerous studies show that U18666A impacts the function of cholesterol trafficking to control the metabolism and transport of amyloid precursor proteins (APPs). Treating cortical neurons with U18666A may provide a new in vitro model system for studying the underlying molecular process of NPC, AD, HD, and PD. In this article, we review the mechanism and function of U18666A as a vital tool for studying cholesterol mechanisms in neurological diseases related to abnormal cholesterol metabolism, such as AD, NPC, HD, and PD.
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Affiliation(s)
| | | | - Ehsan Derafsh
- Windsor University School of Medicine, Cayon, Saint Kitts and Nevis
| | | | | | - Siamak Soltani
- Department of Forensic Medicine, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Meead Hadi
- Department Of Microbiology, Faculty of Basic Sciences, Tehran Central Branch, Islamic Azad University, Tehran, Iran
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Lucarelli M, Camuso S, Di Pietro C, Bruno F, La Rosa P, Marazziti D, Fiorenza MT, Canterini S. Reduced Cerebellar BDNF Availability Affects Postnatal Differentiation and Maturation of Granule Cells in a Mouse Model of Cholesterol Dyshomeostasis. Mol Neurobiol 2023; 60:5395-5410. [PMID: 37314654 PMCID: PMC10415459 DOI: 10.1007/s12035-023-03435-3] [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: 01/25/2023] [Accepted: 06/06/2023] [Indexed: 06/15/2023]
Abstract
Niemann-Pick type C1 (NPC1) disease is a lysosomal lipid storage disorder due to mutations in the NPC1 gene resulting in the accumulation of cholesterol within the endosomal/lysosomal compartments. The prominent feature of the disorder is the progressive Purkinje cell degeneration leading to ataxia.In a mouse model of NPC1 disease, we have previously demonstrated that impaired Sonic hedgehog signaling causes defective proliferation of granule cells (GCs) and abnormal cerebellar morphogenesis. Studies conducted on cortical and hippocampal neurons indicate a functional interaction between Sonic hedgehog and brain-derived neurotrophic factor (BDNF) expression, leading us to hypothesize that BDNF signaling may be altered in Npc1 mutant mice, contributing to the onset of cerebellar alterations present in NPC1 disease before the appearance of signs of ataxia.We characterized the expression/localization patterns of the BDNF and its receptor, tropomyosin-related kinase B (TrkB), in the early postnatal and young adult cerebellum of the Npc1nmf164 mutant mouse strain.In Npc1nmf164 mice, our results show (i) a reduced expression of cerebellar BDNF and pTrkB in the first 2 weeks postpartum, phases in which most GCs complete the proliferative/migrative program and begin differentiation; (ii) an altered subcellular localization of the pTrkB receptor in GCs, both in vivo and in vitro; (iii) reduced chemotactic response to BDNF in GCs cultured in vitro, associated with impaired internalization of the activated TrkB receptor; (iv) an overall increase in dendritic branching in mature GCs, resulting in impaired differentiation of the cerebellar glomeruli, the major synaptic complex between GCs and mossy fibers.
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Affiliation(s)
- Micaela Lucarelli
- Division of Neuroscience, Dept. of Psychology, University La Sapienza, Rome, Italy
- PhD Program in Behavioral Neuroscience, Sapienza University of Rome, Rome, Italy
| | - Serena Camuso
- Division of Neuroscience, Dept. of Psychology, University La Sapienza, Rome, Italy
- PhD Program in Behavioral Neuroscience, Sapienza University of Rome, Rome, Italy
| | - Chiara Di Pietro
- Institute of Biochemistry and Cell Biology, Italian National Research Council (CNR), I-00015, Monterotondo Scalo, Italy
| | - Francesco Bruno
- Regional Neurogenetic Centre (CRN), Department of Primary Care, ASP, 88046, Lamezia Terme, Catanzaro, Italy
- Association for Neurogenetic Research (ARN), 88046, Lamezia Terme, Italy
| | - Piergiorgio La Rosa
- Division of Neuroscience, Dept. of Psychology, University La Sapienza, Rome, Italy
- European Center for Brain Research, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Daniela Marazziti
- Institute of Biochemistry and Cell Biology, Italian National Research Council (CNR), I-00015, Monterotondo Scalo, Italy
| | - Maria Teresa Fiorenza
- Division of Neuroscience, Dept. of Psychology, University La Sapienza, Rome, Italy
- European Center for Brain Research, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Sonia Canterini
- Division of Neuroscience, Dept. of Psychology, University La Sapienza, Rome, Italy.
- European Center for Brain Research, IRCCS Fondazione Santa Lucia, Rome, Italy.
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Assefi M, Bijan Rostami R, Ebrahimi M, Altafi M, Tehrany PM, Zaidan HK, Talib Al-Naqeeb BZ, Hadi M, Yasamineh S, Gholizadeh O. Potential use of the cholesterol transfer inhibitor U18666A as an antiviral drug for research on various viral infections. Microb Pathog 2023; 179:106096. [PMID: 37011734 DOI: 10.1016/j.micpath.2023.106096] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 03/30/2023] [Accepted: 03/31/2023] [Indexed: 04/04/2023]
Abstract
Cholesterol plays critical functions in arranging the biophysical attributes of proteins and lipids in the plasma membrane. For various viruses, an association with cholesterol for virus entrance and/or morphogenesis has been demonstrated. Therefore, the lipid metabolic pathways and the combination of membranes could be targeted to selectively suppress the virus replication steps as a basis for antiviral treatment. U18666A is a cationic amphiphilic drug (CAD) that affects intracellular transport and cholesterol production. A robust tool for investigating lysosomal cholesterol transfer and Ebola virus infection is an androstenolone derived termed U18666A that suppresses three enzymes in the cholesterol biosynthesis mechanism. In addition, U18666A inhibited low-density lipoprotein (LDL)-induced downregulation of LDL receptor and triggered lysosomal aggregation of cholesterol. According to reports, U18666A inhibits the reproduction of baculoviruses, filoviruses, hepatitis, coronaviruses, pseudorabies, HIV, influenza, and flaviviruses, as well as chikungunya and flaviviruses. U18666A-treated viral infections may act as a novel in vitro model system to elucidate the cholesterol mechanism of several viral infections. In this article, we discuss the mechanism and function of U18666A as a potent tool for studying cholesterol mechanisms in various viral infections.
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Peruzzu D, Boussadia Z, Fratini F, Spadaro F, Bertuccini L, Sanchez M, Carollo M, Matarrese P, Falchi M, Iosi F, Raggi C, Parolini I, Carè A, Sargiacomo M, Gagliardi MC, Fecchi K. Inhibition of cholesterol transport impairs Cav-1 trafficking and small extracellular vesicles secretion, promoting amphisome formation in melanoma cells. Traffic 2023; 24:76-94. [PMID: 36519961 DOI: 10.1111/tra.12878] [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: 11/05/2021] [Revised: 11/22/2022] [Accepted: 12/06/2022] [Indexed: 12/23/2022]
Abstract
Caveolin-1 (Cav-1) is a fundamental constituent of caveolae, whose functionality and structure are strictly dependent on cholesterol. In this work the U18666A inhibitor was used to study the role of cholesterol transport in the endosomal degradative-secretory system in a metastatic human melanoma cell line (WM266-4). We found that U18666A induces a shift of Cav-1 from the plasma membrane to the endolysosomal compartment, which is involved, through Multi Vesicular Bodies (MVBs), in the formation and release of small extracellular vesicles (sEVs). Moreover, this inhibitor induces an increase in the production of sEVs with chemical-physical characteristics similar to control sEVs but with a different protein composition (lower expression of Cav-1 and increase of LC3II) and reduced transfer capacity on target cells. Furthermore, we determined that U18666A affects mitochondrial function and also cancer cell aggressive features, such as migration and invasion. Taken together, these results indicate that the blockage of cholesterol transport, determining the internalization of Cav-1, may modify sEVs secretory pathways through an increased fusion between autophagosomes and MVBs to form amphisome, which in turn fuses with the plasma membrane releasing a heterogeneous population of sEVs to maintain homeostasis and ensure correct cellular functionality.
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Affiliation(s)
- Daniela Peruzzu
- Center for Gender-Specific Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Zaira Boussadia
- National Center for Drug Research and Evaluation, Istituto Superiore di Sanità, Rome, Italy
| | - Federica Fratini
- Core Facilities Technical Scientific Service, Istituto Superiore di Sanità, Rome, Italy
| | - Francesca Spadaro
- Core Facilities Technical Scientific Service, Istituto Superiore di Sanità, Rome, Italy
| | - Lucia Bertuccini
- Core Facilities Technical Scientific Service, Istituto Superiore di Sanità, Rome, Italy
| | - Massimo Sanchez
- Core Facilities Technical Scientific Service, Istituto Superiore di Sanità, Rome, Italy
| | - Maria Carollo
- Core Facilities Technical Scientific Service, Istituto Superiore di Sanità, Rome, Italy
| | - Paola Matarrese
- Center for Gender-Specific Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Mario Falchi
- National Center for HIV/AIDS Research, Istituto Superiore di Sanità, Rome
| | - Francesca Iosi
- Core Facilities Technical Scientific Service, Istituto Superiore di Sanità, Rome, Italy
| | - Carla Raggi
- National Center for the control and evaluation of Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Isabella Parolini
- Department Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Alessandra Carè
- Center for Gender-Specific Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Massimo Sargiacomo
- National Center for Global Health, Istituto Superiore di Sanità, Rome, Italy
| | | | - Katia Fecchi
- Center for Gender-Specific Medicine, Istituto Superiore di Sanità, Rome, Italy
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Semba Y, Yamamoto S, Takahashi S, Shinomiya T, Nagahara Y. C-kit inhibitor masitinib induces reactive oxygen species-dependent apoptosis in c-kit-negative HepG2 cells. Eur J Pharmacol 2022; 931:175183. [DOI: 10.1016/j.ejphar.2022.175183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 07/17/2022] [Accepted: 08/01/2022] [Indexed: 11/03/2022]
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Abtahi R, Karimzadeh P, Aryani O, Akbarzadeh D, Salehpour S, Rezayi A, Tonekaboni SH, Emameh RZ, Houshmand M. Identification of novel mutations among Iranian NPC1 patients: a bioinformatics approach to predict pathogenic mutations. Hereditas 2022; 159:8. [PMID: 35086560 PMCID: PMC8793247 DOI: 10.1186/s41065-022-00224-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 12/29/2021] [Indexed: 11/24/2022] Open
Abstract
Background Niemann-Pick disease type C (NPC) is a rare lysosomal neurovisceral storage disease caused by mutations in the NPC 1 (95%) or NPC2 (5%) genes. The products of NPC1 and NPC2 genes play considerable roles in glycolipid and cholesterol trafficking, which could consequently lead to NPC disease with variable phenotypes displaying a broad spectrum of symptoms. Materials In the present study 35 Iranian NPC unrelated patients were enrolled. These patients were first analysed by the Filipin Staining test of cholesterol deposits in cells for NPC diagnostics. Genomic DNA was extracted from the samples of peripheral blood leukocytes in EDTA following the manufacturer's protocol. All exon–intron boundaries and coding exons of the NPC1gene were amplified by polymerase chain reaction (PCR) using appropriate sets of primers. Thereafter, the products of PCR were sequenced and analysed using the NCBI database (https://blast.ncbi.nlm.nih.gov/Blast.cgi). The variants were reviewed by some databases including the Human Gene Mutation Database (HGMD) (http://www.hgmd.cf.ac.uk/ac/index.php) and ClinVar (https://www.ncbi.nlm.nih.gov/clinvar (. Moreover, all the variants were manually classified in terms of the American College of Medical Genetics and Genomics (ACMG) guideline. Results The sequence analysis revealed 20 different variations, 10 of which are new, including one nonsense mutation (c.406C > T); three small deletions, (c.3126delC, c.2920_2923delCCTG, and c.2037delG); and six likely pathogenic missense mutations, (c.542C > A, c.1970G > A, c.1993C > G, c.2821 T > C, c.2872C > G, and c.3632 T > A). Finally, the pathogenicity of these new variants was determined using the ACMG guidelines. Conclusion The present study aimed to facilitate the prenatal diagnosis of NPC patients in the future. In this regard, we identified 10 novel mutations, and verified that the majority of them occurred in six NPC1 exons (5, 8, 9, 13, 19, and 21), that should be considered with a high priority for Iranian patients' cost-effective evaluation.
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Affiliation(s)
- Rezvan Abtahi
- Department of Medical Genetics, National Institute for Genetic Engineering and Biotechnology, (NIGEB), 14965/161, Tehran, Iran
| | - Parvaneh Karimzadeh
- Pediatric Neurology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | - Diba Akbarzadeh
- Student's Research Committee, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Shadab Salehpour
- Department of Pediatric Endocrinology, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Alireza Rezayi
- Department of Pediatrics Neurology, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Seyed Hassan Tonekaboni
- Pediatric Neurology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Reza Zolfaghari Emameh
- Department of Energy and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology (NIGEB), 14965/161, Tehran, Iran
| | - Massoud Houshmand
- Department of Medical Genetics, National Institute for Genetic Engineering and Biotechnology, (NIGEB), 14965/161, Tehran, Iran. .,Department of Medical Laboratory Science, Knowledge University, Erbil, Kurdistan Region, Iraq.
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9
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Wu Q, Cortez L, Kamali-Jamil R, Sim V, Wille H, Kar S. Implications of exosomes derived from cholesterol-accumulated astrocytes in Alzheimer's disease pathology. Dis Model Mech 2021; 14:dmm048929. [PMID: 34524402 PMCID: PMC8560497 DOI: 10.1242/dmm.048929] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 09/06/2021] [Indexed: 12/25/2022] Open
Abstract
Amyloid β (Aβ) peptides generated from the amyloid precursor protein (APP) play a critical role in the development of Alzheimer's disease (AD) pathology. Aβ-containing neuronal exosomes, which represent a novel form of intercellular communication, have been shown to influence the function/vulnerability of neurons in AD. Unlike neurons, the significance of exosomes derived from astrocytes remains unclear. In this study, we evaluated the significance of exosomes derived from U18666A-induced cholesterol-accumulated astrocytes in the development of AD pathology. Our results show that cholesterol accumulation decreases exosome secretion, whereas lowering cholesterol increases exosome secretion, from cultured astrocytes. Interestingly, exosomes secreted from U18666A-treated astrocytes contain higher levels of APP, APP-C-terminal fragments, soluble APP, APP secretases and Aβ1-40 than exosomes secreted from control astrocytes. Furthermore, we show that exosomes derived from U18666A-treated astrocytes can lead to neurodegeneration, which is attenuated by decreasing Aβ production or by neutralizing exosomal Aβ peptide with an anti-Aβ antibody. These results, taken together, suggest that exosomes derived from cholesterol-accumulated astrocytes can play an important role in trafficking APP/Aβ peptides and influencing neuronal viability in the affected regions of the AD brain.
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Affiliation(s)
- Qi Wu
- Department of Medicine (Neurology), University of Alberta, Edmonton, AB T6G 2G3, Canada
| | - Leonardo Cortez
- Department of Medicine (Neurology), University of Alberta, Edmonton, AB T6G 2G3, Canada
| | - Razieh Kamali-Jamil
- Department of Biochemistry, Center for Prions and Protein Folding Diseases, University of Alberta, Edmonton, AB T6G 2G3, Canada
| | - Valerie Sim
- Department of Medicine (Neurology), University of Alberta, Edmonton, AB T6G 2G3, Canada
| | - Holger Wille
- Department of Biochemistry, Center for Prions and Protein Folding Diseases, University of Alberta, Edmonton, AB T6G 2G3, Canada
| | - Satyabrata Kar
- Department of Medicine (Neurology), University of Alberta, Edmonton, AB T6G 2G3, Canada
- Department of Biochemistry, Center for Prions and Protein Folding Diseases, University of Alberta, Edmonton, AB T6G 2G3, Canada
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10
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Lai SSM, Ng KY, Koh RY, Chok KC, Chye SM. Endosomal-lysosomal dysfunctions in Alzheimer's disease: Pathogenesis and therapeutic interventions. Metab Brain Dis 2021; 36:1087-1100. [PMID: 33881723 DOI: 10.1007/s11011-021-00737-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 04/08/2021] [Indexed: 12/14/2022]
Abstract
The endosomal-lysosomal system mediates the process of protein degradation through endocytic pathway. This system consists of early endosomes, late endosomes, recycling endosomes and lysosomes. Each component in the endosomal-lysosomal system plays individual crucial role and they work concordantly to ensure protein degradation can be carried out functionally. Dysregulation in the endosomal-lysosomal system can contribute to the pathogenesis of neurodegenerative diseases such as Alzheimer's disease (AD). In AD endosomal-lysosomal abnormalities are the earliest pathological features to note and hence it is important to understand the involvement of endosomal-lysosomal dysfunction in the pathogenesis of AD. In-depth understanding of this dysfunction can allow development of new therapeutic intervention to prevent and treat AD.
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Affiliation(s)
- Shereen Shi Min Lai
- School of Health Science, International Medical University, 57000, Kuala Lumpur, Malaysia
| | - Khuen Yen Ng
- School of Pharmacy, Monash University Malaysia, 47500, Selangor, Malaysia
| | - Rhun Yian Koh
- Division of Biomedical Science and Biotechnology, School of Health Science, International Medical University, No. 126, Jalan Jalil Perkasa 19, Bukit Jalil, 57000, Kuala Lumpur, Malaysia
| | - Kian Chung Chok
- School of Health Science, International Medical University, 57000, Kuala Lumpur, Malaysia
| | - Soi Moi Chye
- Division of Biomedical Science and Biotechnology, School of Health Science, International Medical University, No. 126, Jalan Jalil Perkasa 19, Bukit Jalil, 57000, Kuala Lumpur, Malaysia.
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11
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Understanding and Treating Niemann-Pick Type C Disease: Models Matter. Int J Mol Sci 2020; 21:ijms21238979. [PMID: 33256121 PMCID: PMC7730076 DOI: 10.3390/ijms21238979] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 11/20/2020] [Accepted: 11/23/2020] [Indexed: 02/06/2023] Open
Abstract
Biomedical research aims to understand the molecular mechanisms causing human diseases and to develop curative therapies. So far, these goals have been achieved for a small fraction of diseases, limiting factors being the availability, validity, and use of experimental models. Niemann–Pick type C (NPC) is a prime example for a disease that lacks a curative therapy despite substantial breakthroughs. This rare, fatal, and autosomal-recessive disorder is caused by defects in NPC1 or NPC2. These ubiquitously expressed proteins help cholesterol exit from the endosomal–lysosomal system. The dysfunction of either causes an aberrant accumulation of lipids with patients presenting a large range of disease onset, neurovisceral symptoms, and life span. Here, we note general aspects of experimental models, we describe the line-up used for NPC-related research and therapy development, and we provide an outlook on future topics.
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12
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APP Osaka Mutation in Familial Alzheimer's Disease-Its Discovery, Phenotypes, and Mechanism of Recessive Inheritance. Int J Mol Sci 2020; 21:ijms21041413. [PMID: 32093100 PMCID: PMC7073033 DOI: 10.3390/ijms21041413] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Revised: 02/17/2020] [Accepted: 02/17/2020] [Indexed: 12/14/2022] Open
Abstract
Alzheimer’s disease is believed to begin with synaptic dysfunction caused by soluble Aβ oligomers. When this oligomer hypothesis was proposed in 2002, there was no direct evidence that Aβ oligomers actually disrupt synaptic function to cause cognitive impairment in humans. In patient brains, both soluble and insoluble Aβ species always coexist, and therefore it is difficult to determine which pathologies are caused by Aβ oligomers and which are caused by amyloid fibrils. Thus, no validity of the oligomer hypothesis was available until the Osaka mutation was discovered. This mutation, which was found in a Japanese pedigree of familial Alzheimer’s disease, is the deletion of codon 693 of APP gene, resulting in mutant Aβ lacking the 22nd glutamate. Only homozygous carriers suffer from dementia. In vitro studies revealed that this mutation has a very unique character that accelerates Aβ oligomerization but does not form amyloid fibrils. Model mice expressing this mutation demonstrated that all pathologies of Alzheimer’s disease can be induced by Aβ oligomers alone. In this review, we describe the story behind the discovery of the Osaka mutation, summarize the mutant’s phenotypes, and propose a mechanism of its recessive inheritance.
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Liang XD, Zhang YN, Liu CC, Chen J, Chen XN, Sattar Baloch A, Zhou B. U18666A inhibits classical swine fever virus replication through interference with intracellular cholesterol trafficking. Vet Microbiol 2019; 238:108436. [PMID: 31648726 DOI: 10.1016/j.vetmic.2019.108436] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 09/09/2019] [Accepted: 10/01/2019] [Indexed: 12/13/2022]
Abstract
The level of cholesterol in host cells has been demonstrated to affect viral infection. Our previous studies showed that cholesterol-rich membrane rafts mediated the entry of classical swine fever virus (CSFV) into PK-15 or 3D4/21 cells, but the role of cholesterol post entry was still not clear. In this study, we found that CSFV replication before fusion was affected when the cholesterol trafficking in infected cells was disrupted using a cholesterol transport inhibitor, U18666A. Our data showed that U18666A affected both the fusion and replication steps in the life cycle of the virus, but not its binding and entry steps. The subsequent experiments confirmed that niemann-pick C1 (NPC1), a lysosomal membrane protein that helps cholesterol to leave the lysosome, was affected by U18666A, which led to the accumulation of cholesterol in lysosomes and inhibition of CSFV replication. Imipramine, a cationic hydrophobic amine similar to U18666A, also inhibited CSFV replication via similar mechanism. Surprisingly, the antiviral effect of U18666A was restored by the histone deacetylase inhibitor (HDACi), Vorinostat, which suggested that HDACi reverted the dysfunction of NPC1, and intra-cellular cholesterol accumulation disappeared and CSFV replicability resumed. Together, these data indicated that CSFV transformed from early endosome and late endosome into lysosome after endocytosis for further replication and that U18666A was a potential drug candidate for anti-pestivirus treatment.
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Affiliation(s)
- Xiao-Dong Liang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Yun-Na Zhang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Chun-Chun Liu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Jing Chen
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Xiong-Nan Chen
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Abdul Sattar Baloch
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Bin Zhou
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.
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14
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Wang H, Feng Z, Yang C, Liu J, Medina JE, Aghvami SA, Dinulescu DM, Liu J, Fraden S, Xu B. Unraveling the Cellular Mechanism of Assembling Cholesterols for Selective Cancer Cell Death. Mol Cancer Res 2018; 17:907-917. [PMID: 30552234 DOI: 10.1158/1541-7786.mcr-18-0931] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 10/05/2018] [Accepted: 11/21/2018] [Indexed: 12/17/2022]
Abstract
Acquired drug resistance remains a challenge in chemotherapy. Here we show enzymatic, in situ assembling of cholesterol derivatives to act as polypharmaceuticals for selectively inducing death of cancer cells via multiple pathways and without inducing acquired drug resistance. A conjugate of tyrosine and cholesterol (TC), formed by enzyme-catalyzed dephosphorylation of phosphorylate TC, self-assembles selectively on or in cancer cells. Acting as polypharmaceuticals, the assemblies of TC augment lipid rafts, aggregate extrinsic cell death receptors (e.g., DR5, CD95, or TRAILR), modulate the expression of oncoproteins (e.g., Src and Akt), disrupt the dynamics of cytoskeletons (e.g., actin filaments or microtubules), induce endoplasmic reticulum stress, and increase the production of reactive oxygen species, thus resulting in cell death and preventing acquired drug resistance. Moreover, the assemblies inhibit the growth of platinum-resistant ovarian cancer tumor in a murine model. This work illustrates the use of instructed assembly (iA) in cellular environment to form polypharmaceuticals in situ that not only interact with multiple proteins, but also modulate membrane dynamics for developing novel anticancer therapeutics. IMPLICATIONS: As a multifaceted strategy for controlling cancer cell death, iA minimized acquired resistance of cancer cells, which is a new strategy to amplify the genetic difference between cancer and normal cells and provides a promise for overcoming drug resistance in cancer therapy.Visual Overview: http://mcr.aacrjournals.org/content/molcanres/17/4/907/F1.large.jpg.
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Affiliation(s)
- Huaimin Wang
- Department of Chemistry, Brandeis University, Waltham, Massachusetts
| | - Zhaoqianqi Feng
- Department of Chemistry, Brandeis University, Waltham, Massachusetts
| | - Cuihong Yang
- Chinese Academy of Medical Science & Peking Union Medical College, Tianjin, China
| | - Jinjian Liu
- Chinese Academy of Medical Science & Peking Union Medical College, Tianjin, China
| | - Jamie E Medina
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - S Ali Aghvami
- Department of Physics, Brandeis University, Waltham, Massachusetts
| | - Daniela M Dinulescu
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Jianfeng Liu
- Chinese Academy of Medical Science & Peking Union Medical College, Tianjin, China
| | - Seth Fraden
- Department of Physics, Brandeis University, Waltham, Massachusetts
| | - Bing Xu
- Department of Chemistry, Brandeis University, Waltham, Massachusetts.
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15
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Endosomal-Lysosomal Cholesterol Sequestration by U18666A Differentially Regulates Amyloid Precursor Protein (APP) Metabolism in Normal and APP-Overexpressing Cells. Mol Cell Biol 2018. [PMID: 29530923 DOI: 10.1128/mcb.00529-17] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Amyloid β (Aβ) peptide, derived from amyloid precursor protein (APP), plays a critical role in the development of Alzheimer's disease. Current evidence indicates that altered levels or subcellular distribution of cholesterol can regulate Aβ production and clearance, but it remains unclear how cholesterol sequestration within the endosomal-lysosomal (EL) system can influence APP metabolism. Thus, we evaluated the effects of U18666A, which triggers cholesterol redistribution within the EL system, on mouse N2a cells expressing different levels of APP in the presence or absence of extracellular cholesterol and lipids provided by fetal bovine serum (FBS). Our results reveal that U18666A and FBS differentially increase the levels of APP and its cleaved products, the α-, β-, and η-C-terminal fragments, in N2a cells expressing normal levels of mouse APP (N2awt), higher levels of human wild-type APP (APPwt), or "Swedish" mutant APP (APPsw). The cellular levels of Aβ1-40/Aβ1-42 were markedly increased in U18666A-treated APPwt and APPsw cells. Our studies further demonstrate that APP and its cleaved products are partly accumulated in the lysosomes, possibly due to decreased clearance. Finally, we show that autophagy inhibition plays a role in mediating U18666A effects. Collectively, these results suggest that altered levels and distribution of cholesterol and lipids can differentially regulate APP metabolism depending on the nature of APP expression.
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16
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Yang H, Wang Y, Kar S. Effects of cholesterol transport inhibitor U18666A on APP metabolism in rat primary astrocytes. Glia 2017; 65:1728-1743. [PMID: 28722194 DOI: 10.1002/glia.23191] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 06/27/2017] [Accepted: 06/27/2017] [Indexed: 12/21/2022]
Abstract
Amyloid β (Aβ) peptides generated from the amyloid precursor protein (APP) play an important role in the degeneration of neurons and development of Alzheimer's disease (AD). Current evidence indicates that high levels of cholesterol-which increase the risk of developing AD-can influence Aβ production in neurons. However, it remains unclear how altered level/subcellular distribution of cholesterol in astrocytes can influence APP metabolism. In this study, we evaluated the effects of cholesterol transport inhibitor U18666A-a class II amphiphile that triggers redistribution of cholesterol within the endosomal-lysosomal (EL) system-on APP levels and metabolism in rat primary cultured astrocytes. Our results revealed that U18666A increased the levels of the APP holoprotein and its cleaved products (α-/β-/η-CTFs) in cultured astrocytes, without altering the total levels of cholesterol or cell viability. The cellular levels of Aβ1-40 were also found to be markedly increased, while secretory levels of Aβ1-40 were decreased in U18666A-treated astrocytes. We further report a corresponding increase in the activity of the enzymes regulating APP processing, such as α-secretase, β-secretase, and γ-secretase as a consequence of U18666A treatment. Additionally, APP-cleaved products are partly accumulated in the lysosomes following cholesterol sequestration within EL system possibly due to decreased clearance. Interestingly, serum delipidation attenuated enhanced levels of APP and its cleaved products following U18666A treatment. Collectively, these results suggest that cholesterol sequestration within the EL system in astrocytes can influence APP metabolism and the accumulation of APP-cleaved products including Aβ peptides, which can contribute to the development of AD pathology.
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Affiliation(s)
- Hongyan Yang
- Department of Psychiatry, Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, T6G 2M8, Canada
- Department of Pharmacology, Qiqihar Medical University, Qiqihar, Heilongjiang, China
| | - Yanlin Wang
- Department of Psychiatry, Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, T6G 2M8, Canada
| | - Satyabrata Kar
- Department of Psychiatry, Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, T6G 2M8, Canada
- Department of Medicine, Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, T6G 2M8, Canada
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Quan X, Chen X, Sun D, Xu B, Zhao L, Shi X, Liu H, Gao B, Lu X. The mechanism of the effect of U18666a on blocking the activity of 3β-hydroxysterol Δ-24-reductase (DHCR24): molecular dynamics simulation study and free energy analysis. J Mol Model 2016; 22:46. [DOI: 10.1007/s00894-016-2907-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 01/07/2016] [Indexed: 11/28/2022]
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Yao K, Wu J, Zhang J, Bo J, Hong Z, Zu H. Protective Effect of DHT on Apoptosis Induced by U18666A via PI3K/Akt Signaling Pathway in C6 Glial Cell Lines. Cell Mol Neurobiol 2015; 36:801-9. [PMID: 26340949 DOI: 10.1007/s10571-015-0263-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Accepted: 08/27/2015] [Indexed: 11/27/2022]
Abstract
Various useful animal models, such as Alzheimer's disease and Niemann-Pick disease, were provided by U18666A. However, the pathogenesis of U18666A-induced diseases, including U18666A-mediated apoptosis, remains incompletely elucidated, and therapeutic strategies are still limited. Dihydrotestosterone (DHT) has been reported to contribute to the prevention and treatment of neurodegenerative disorders. Our study investigated the neuroprotective activity of DHT in U18666A-related diseases. Apoptosis of C6 cells was detected by Hoechst 33258 fluorescent staining and flow cytometry with annexin V-FITC/PI dual staining. Cell viability was assessed using Cell Counting Kit-8. Expression of apoptosis-related proteins, such as Akt, seladin-1, Bcl-2 family proteins, and caspase-3, was determined using Western blot. Our results demonstrated that the apoptotic rate of C6 cells significantly increased after U18666A addition, but was remarkably reduced after DHT treatment. Pretreatment with DHT attenuated U18666A-induced cell viability loss. PI3K inhibitor LY294002 could suppress DHT anti-apoptotic effect. Furthermore, we discovered that U18666A could significantly downregulate seladin-1 expression in a dose-dependent manner, but no significant change was observed in Bcl-xL, Bax, and P-Akt protein expressions. Compared with U18666A-treated group, the expression of P-Akt, seladin-1, and Bcl-xL significantly increased, and the expression of Bax and caspase-3 remarkably reduced after DHT treatment. However, in the presence of LY294002, the effect of DHT was reversed. In conclusion, we found that seladin-1 may take part in U18666A-induced apoptosis. DHT may inhibit U18666A-induced apoptosis by regulating downstream apoptosis-related proteins including seladin-1, caspase-3, Bcl-xL, and Bax through activation of the PI3K/Akt signal pathway.
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Affiliation(s)
- Kai Yao
- Department of Neurology, Jinshan Hospital Affiliated to Fudan University, No. 1508 Longhang Road, Jinshan District, Shanghai, 201508, China
| | - Junfeng Wu
- Department of Neurology, Jinshan Hospital Affiliated to Fudan University, No. 1508 Longhang Road, Jinshan District, Shanghai, 201508, China
| | - Jianfeng Zhang
- Department of Neurology, Jinshan Hospital Affiliated to Fudan University, No. 1508 Longhang Road, Jinshan District, Shanghai, 201508, China
| | - Jimei Bo
- Department of Neurology, Jinshan Hospital Affiliated to Fudan University, No. 1508 Longhang Road, Jinshan District, Shanghai, 201508, China
| | - Zhen Hong
- Department of Neurology, Jinshan Hospital Affiliated to Fudan University, No. 1508 Longhang Road, Jinshan District, Shanghai, 201508, China
| | - Hengbing Zu
- Department of Neurology, Jinshan Hospital Affiliated to Fudan University, No. 1508 Longhang Road, Jinshan District, Shanghai, 201508, China.
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Abstract
Recent work demonstrated that the Niemann-Pick C1 (NPC1) protein is an essential entry receptor for filoviruses. While previous studies focused on filovirus entry requirements of NPC1 in vitro, its roles in filovirus replication and pathogenesis in vivo remain unclear. Here, we evaluated the importance of NPC1, and its partner in cholesterol transport, NPC2, by using a mouse model of Ebolavirus (EBOV) disease. We found that, whereas wild-type mice had high viral loads and succumbed to EBOV infection, Npc1−/− mice were entirely free of viral replication and completely protected from EBOV disease. Interestingly, Npc1+/− mice transiently developed high levels of viremia, but were nevertheless substantially protected from EBOV challenge. We also found Npc2−/− mice to be fully susceptible to EBOV infection, while Npc1−/− mice treated to deplete stored lysosomal cholesterol remained completely resistant to EBOV infection. These results provide mechanistic evidence that NPC1 is directly required for EBOV infection in vivo, with little or no role for NPC1/NPC2-dependent cholesterol transport. Finally, we assessed the in vivo antiviral efficacies of three compounds known to inhibit NPC1 function or NPC1-glycoprotein binding in vitro. Two compounds reduced viral titers in vivo and provided a modest, albeit not statistically significant, degree of protection. Taken together, our results show that NPC1 is critical for replication and pathogenesis in animals and is a bona fide target for development of antifilovirus therapeutics. Additionally, our findings with Npc1+/− mice raise the possibility that individuals heterozygous for NPC1 may have a survival advantage in the face of EBOV infection. Researchers have been searching for an essential filovirus receptor for decades, and numerous candidate receptors have been proposed. However, none of the proposed candidate receptors has proven essential in all in vitro scenarios, nor have they proven essential when evaluated using animal models. In this report, we provide the first example of a knockout mouse that is completely refractory to EBOV infection, replication, and disease. The findings detailed here provide the first critical in vivo data illustrating the absolute requirement of NPC1 for filovirus infection in mice. Our work establishes NPC1 as a legitimate target for the development of anti-EBOV therapeutics. However, the limited success of available NPC1 inhibitors to protect mice from EBOV challenge highlights the need for new molecules or approaches to target NPC1 in vivo.
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Kresojević N, Dobričić V, Svetel M, Kostić V. Mutations in Niemann Pick type C gene are risk factor for Alzheimer's disease. Med Hypotheses 2014; 83:559-62. [PMID: 25220527 DOI: 10.1016/j.mehy.2014.08.025] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 08/13/2014] [Accepted: 08/24/2014] [Indexed: 11/30/2022]
Abstract
Alzheimer's disease (AD) is the most common form of dementia characterized by deterioration of memory and other cognitive domains which leads to death in 3-9years after diagnosis. In addition to mutations in APP, PSEN1 and PSEN2 genes, that cause early onset autosomal dominant AD, several genetic risk factors for late onset AD are now known. There is another distinctive neurodegenerative lysosomal storage disorder - Niemann-Pick type C (NPC) that is sometimes referred to as "Childhood Alzheimer's". NPC is autosomal recessive disease caused by mutations in the NPC1 or NPC2 genes. NPC and AD share some biochemical and pathological similarities which are discussed in this paper. On the other hand, there is a well documented connection between other autosomal recessive lysosomal storage disorder - Gaucher's disease (GD) and neurodegenerative disorder - Parkinson's disease (PD). It has been shown that GD patients have 20-fold increased life-time risk of developing PD. Surprisingly, even heterozygous carriers of mutations in glucocerebrosidase gene (GBA) have increased risk for developing PD. Having in mind above mentioned correlations, we hypothesized that heterozygous mutations in the NPC gene may act as an independent risk factor for Alzheimer's disease. If true, this would expand link between lysosomal disorders and neurodegenerative diseases. Also, if heterozygous NPC1/2 mutation carriers develop AD we assume it would be worth trying with miglustat-specific therapy recommended for NPC disease.
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Affiliation(s)
- Nikola Kresojević
- Neurology Clinic, CCS, School of Medicine, University of Belgrade, Dr Subotića starijeg 6, 11000 Belgrade, Serbia
| | - Valerija Dobričić
- Neurology Clinic, CCS, School of Medicine, University of Belgrade, Dr Subotića starijeg 6, 11000 Belgrade, Serbia
| | - Marina Svetel
- Neurology Clinic, CCS, School of Medicine, University of Belgrade, Dr Subotića starijeg 6, 11000 Belgrade, Serbia
| | - Vladimir Kostić
- Neurology Clinic, CCS, School of Medicine, University of Belgrade, Dr Subotića starijeg 6, 11000 Belgrade, Serbia.
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21
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Yamasaki T, Suzuki A, Hasebe R, Horiuchi M. Comparison of the anti-prion mechanism of four different anti-prion compounds, anti-PrP monoclonal antibody 44B1, pentosan polysulfate, chlorpromazine, and U18666A, in prion-infected mouse neuroblastoma cells. PLoS One 2014; 9:e106516. [PMID: 25181483 PMCID: PMC4152300 DOI: 10.1371/journal.pone.0106516] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Accepted: 08/04/2014] [Indexed: 01/07/2023] Open
Abstract
Molecules that inhibit the formation of an abnormal isoform of prion protein (PrPSc) in prion-infected cells are candidate therapeutic agents for prion diseases. Understanding how these molecules inhibit PrPSc formation provides logical basis for proper evaluation of their therapeutic potential. In this study, we extensively analyzed the effects of the anti-PrP monoclonal antibody (mAb) 44B1, pentosan polysulfate (PPS), chlorpromazine (CPZ) and U18666A on the intracellular dynamics of a cellular isoform of prion protein (PrPC) and PrPSc in prion-infected mouse neuroblastoma cells to re-evaluate the effects of those agents. MAb 44B1 and PPS rapidly reduced PrPSc levels without altering intracellular distribution of PrPSc. PPS did not change the distribution and levels of PrPC, whereas mAb 44B1 appeared to inhibit the trafficking of cell surface PrPC to organelles in the endocytic-recycling pathway that are thought to be one of the sites for PrPSc formation. In contrast, CPZ and U18666A initiated the redistribution of PrPSc from organelles in the endocytic-recycling pathway to late endosomes/lysosomes without apparent changes in the distribution of PrPC. The inhibition of lysosomal function by monensin or bafilomycin A1 after the occurrence of PrPSc redistribution by CPZ or U18666A partly antagonized PrPSc degradation, suggesting that the transfer of PrPSc to late endosomes/lysosomes, possibly via alteration of the membrane trafficking machinery of cells, leads to PrPSc degradation. This study revealed that precise analysis of the intracellular dynamics of PrPC and PrPSc provides important information for understanding the mechanism of anti-prion agents.
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Affiliation(s)
- Takeshi Yamasaki
- Laboratory of Veterinary Hygiene, Graduate School of Veterinary Medicine, Hokkaido University, Kita-ku, Sapporo, Japan
| | - Akio Suzuki
- Laboratory of Veterinary Hygiene, Graduate School of Veterinary Medicine, Hokkaido University, Kita-ku, Sapporo, Japan
| | - Rie Hasebe
- Laboratory of Veterinary Hygiene, Graduate School of Veterinary Medicine, Hokkaido University, Kita-ku, Sapporo, Japan
| | - Motohiro Horiuchi
- Laboratory of Veterinary Hygiene, Graduate School of Veterinary Medicine, Hokkaido University, Kita-ku, Sapporo, Japan
- * E-mail:
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22
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Martin-Antonio B, Najjar A, Robinson SN, Chew C, Li S, Yvon E, Thomas MW, Mc Niece I, Orlowski R, Muñoz-Pinedo C, Bueno C, Menendez P, Fernández de Larrea C, Urbano-Ispizua A, Shpall EJ, Shah N. Transmissible cytotoxicity of multiple myeloma cells by cord blood-derived NK cells is mediated by vesicle trafficking. Cell Death Differ 2014; 22:96-107. [PMID: 25168239 DOI: 10.1038/cdd.2014.120] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 07/02/2014] [Accepted: 07/09/2014] [Indexed: 12/11/2022] Open
Abstract
Natural killer cells (NK) are important effectors of anti-tumor immunity, activated either by the downregulation of HLA-I molecules on tumor cells and/or the interaction of NK-activating receptors with ligands that are overexpressed on target cells upon tumor transformation (including NKG2D and NKP30). NK kill target cells by the vesicular delivery of cytolytic molecules such as Granzyme-B and Granulysin activating different cell death pathways, which can be Caspase-3 dependent or Caspase-3 independent. Multiple myeloma (MM) remains an incurable neoplastic plasma-cell disorder. However, we previously reported the encouraging observation that cord blood-derived NK (CB-NK), a new source of NK, showed anti-tumor activity in an in vivo murine model of MM and confirmed a correlation between high levels of NKG2D expression by MM cells and increased efficacy of CB-NK in reducing tumor burden. We aimed to characterize the mechanism of CB-NK-mediated cytotoxicity against MM cells. We show a Caspase-3- and Granzyme-B-independent cell death, and we reveal a mechanism of transmissible cell death between cells, which involves lipid-protein vesicle transfer from CB-NK to MM cells. These vesicles are secondarily transferred from recipient MM cells to neighboring MM cells amplifying the initial CB-NK cytotoxicity achieved. This indirect cytotoxicity involves the transfer of NKG2D and NKP30 and leads to lysosomal cell death and decreased levels of reactive oxygen species in MM cells. These findings suggest a novel and unique mechanism of CB-NK cytotoxicity against MM cells and highlight the importance of lipids and lipid transfer in this process. Further, these data provide a rationale for the development of CB-NK-based cellular therapies in the treatment of MM.
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Affiliation(s)
- B Martin-Antonio
- 1] Department of Stem Cell Transplantation and Cellular Therapy, The University of Texs M.D. Anderson Cancer Center, Houston, TX, USA [2] Department of Hematology, Hospital Clinic, IDIBAPS, Josep Carreras Leukaemia Research Institute/University of Barcelona, Barcelona, Spain
| | - A Najjar
- Department of Cancer Systems Imaging, The University of Texs M.D. Anderson Cancer Center, Houston, TX, USA
| | - S N Robinson
- Department of Stem Cell Transplantation and Cellular Therapy, The University of Texs M.D. Anderson Cancer Center, Houston, TX, USA
| | - C Chew
- Department of Stem Cell Transplantation and Cellular Therapy, The University of Texs M.D. Anderson Cancer Center, Houston, TX, USA
| | - S Li
- Department of Stem Cell Transplantation and Cellular Therapy, The University of Texs M.D. Anderson Cancer Center, Houston, TX, USA
| | - E Yvon
- Department of Stem Cell Transplantation and Cellular Therapy, The University of Texs M.D. Anderson Cancer Center, Houston, TX, USA
| | - M W Thomas
- Department of Stem Cell Transplantation and Cellular Therapy, The University of Texs M.D. Anderson Cancer Center, Houston, TX, USA
| | - I Mc Niece
- Department of Stem Cell Transplantation and Cellular Therapy, The University of Texs M.D. Anderson Cancer Center, Houston, TX, USA
| | - R Orlowski
- Department of Lymphoma/Myeloma, The University of Texas M.D. Anderson Cancer Center, Houston, TX, USA
| | - C Muñoz-Pinedo
- Cell Death Regulation Group, Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain
| | - C Bueno
- Josep Carreras Leukemia Research Institute and Cell Therapy Program of the School of Medicine, University of Barcelona, Barcelona, Spain
| | - P Menendez
- 1] Josep Carreras Leukemia Research Institute and Cell Therapy Program of the School of Medicine, University of Barcelona, Barcelona, Spain [2] Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | - C Fernández de Larrea
- Department of Hematology, Hospital Clinic, IDIBAPS, Josep Carreras Leukaemia Research Institute/University of Barcelona, Barcelona, Spain
| | - A Urbano-Ispizua
- Department of Hematology, Hospital Clinic, IDIBAPS, Josep Carreras Leukaemia Research Institute/University of Barcelona, Barcelona, Spain
| | - E J Shpall
- Department of Stem Cell Transplantation and Cellular Therapy, The University of Texs M.D. Anderson Cancer Center, Houston, TX, USA
| | - N Shah
- Department of Stem Cell Transplantation and Cellular Therapy, The University of Texs M.D. Anderson Cancer Center, Houston, TX, USA
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Vitamin E dietary supplementation improves neurological symptoms and decreases c-Abl/p73 activation in Niemann-Pick C mice. Nutrients 2014; 6:3000-17. [PMID: 25079853 PMCID: PMC4145291 DOI: 10.3390/nu6083000] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 07/16/2014] [Accepted: 07/18/2014] [Indexed: 01/04/2023] Open
Abstract
Niemann-Pick C (NPC) disease is a fatal neurodegenerative disorder characterized by the accumulation of free cholesterol in lysosomes. We have previously reported that oxidative stress is the main upstream stimulus activating the proapoptotic c-Abl/p73 pathway in NPC neurons. We have also observed accumulation of vitamin E in NPC lysosomes, which could lead to a potential decrease of its bioavailability. Our aim was to determine if dietary vitamin E supplementation could improve NPC disease in mice. NPC mice received an alpha-tocopherol (α-TOH) supplemented diet and neurological symptoms, survival, Purkinje cell loss, α-TOH and nitrotyrosine levels, astrogliosis, and the c-Abl/p73 pathway functions were evaluated. In addition, the effect of α-TOH on the c-Abl/p73 pathway was evaluated in an in vitro NPC neuron model. The α-TOH rich diet delayed loss of weight, improved coordination and locomotor function and increased the survival of NPC mice. We found increased Purkinje neurons and α-TOH levels and reduced astrogliosis, nitrotyrosine and phosphorylated p73 in cerebellum. A decrease of c-Abl/p73 activation was also observed in the in vitro NPC neurons treated with α-TOH. In conclusion, our results show that vitamin E can delay neurodegeneration in NPC mice and suggest that its supplementation in the diet could be useful for the treatment of NPC patients.
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24
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Desai TM, Marin M, Chin CR, Savidis G, Brass AL, Melikyan GB. IFITM3 restricts influenza A virus entry by blocking the formation of fusion pores following virus-endosome hemifusion. PLoS Pathog 2014; 10:e1004048. [PMID: 24699674 PMCID: PMC3974867 DOI: 10.1371/journal.ppat.1004048] [Citation(s) in RCA: 242] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Accepted: 02/18/2014] [Indexed: 02/04/2023] Open
Abstract
Interferon-induced transmembrane proteins (IFITMs) inhibit infection of diverse enveloped viruses, including the influenza A virus (IAV) which is thought to enter from late endosomes. Recent evidence suggests that IFITMs block virus hemifusion (lipid mixing in the absence of viral content release) by altering the properties of cell membranes. Consistent with this mechanism, excess cholesterol in late endosomes of IFITM-expressing cells has been reported to inhibit IAV entry. Here, we examined IAV restriction by IFITM3 protein using direct virus-cell fusion assay and single virus imaging in live cells. IFITM3 over-expression did not inhibit lipid mixing, but abrogated the release of viral content into the cytoplasm. Although late endosomes of IFITM3-expressing cells accumulated cholesterol, other interventions leading to aberrantly high levels of this lipid did not inhibit virus fusion. These results imply that excess cholesterol in late endosomes is not the mechanism by which IFITM3 inhibits the transition from hemifusion to full fusion. The IFITM3's ability to block fusion pore formation at a post-hemifusion stage shows that this protein stabilizes the cytoplasmic leaflet of endosomal membranes without adversely affecting the lumenal leaflet. We propose that IFITM3 interferes with pore formation either directly, through partitioning into the cytoplasmic leaflet of a hemifusion intermediate, or indirectly, by modulating the lipid/protein composition of this leaflet. Alternatively, IFITM3 may redirect IAV fusion to a non-productive pathway, perhaps by promoting fusion with intralumenal vesicles within multivesicular bodies/late endosomes. Interferon-induced transmembrane proteins (IFITMs) block infection of many enveloped viruses, including the influenza A virus (IAV) that enters from late endosomes. IFITMs are thought to prevent virus hemifusion (merger of contacting leaflets without formation of a fusion pore) by altering the properties of cell membranes. Here we performed single IAV imaging and found that IFITM3 did not interfere with hemifusion, but prevented complete fusion. Also, contrary to a current view that excess cholesterol in late endosomes of IFITM3-expressing cells inhibits IAV entry, we show that cholesterol-laden endosomes are permissive for virus fusion. The ability of IFITM3 to block the formation of fusion pores implies that this protein stabilizes the cytoplasmic leaflet of endosomal membranes, either directly or indirectly, through altering its physical properties. IFITM3 may also redirect IAV to a non-productive pathway by promoting fusion with intralumenal vesicles of late endosomes instead of their limiting membrane.
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Affiliation(s)
- Tanay M. Desai
- Division of Pediatric Infectious Diseases, Emory University Children's Center, Atlanta, Georgia, United States of America
| | - Mariana Marin
- Division of Pediatric Infectious Diseases, Emory University Children's Center, Atlanta, Georgia, United States of America
| | - Christopher R. Chin
- Microbiology and Physiological Systems (MaPS) Department, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - George Savidis
- Microbiology and Physiological Systems (MaPS) Department, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Abraham L. Brass
- Microbiology and Physiological Systems (MaPS) Department, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Gregory B. Melikyan
- Division of Pediatric Infectious Diseases, Emory University Children's Center, Atlanta, Georgia, United States of America
- Children's Healthcare of Atlanta, Atlanta, Georgia, United States of America
- * E-mail:
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Donepezil Enhances Purkinje Cell Survival and Alleviates Motor Dysfunction by Inhibiting Cholesterol Synthesis in a Murine Model of Niemann Pick Disease Type C. J Neuropathol Exp Neurol 2014; 73:234-43. [DOI: 10.1097/nen.0000000000000045] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
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Dai C, Zhang D, Gao R, Zhang X, Li J, Li J. In vitro toxicity of colistin on primary chick cortex neurons and its potential mechanism. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2013; 36:659-666. [PMID: 23892071 DOI: 10.1016/j.etap.2013.06.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Revised: 06/25/2013] [Accepted: 06/29/2013] [Indexed: 06/02/2023]
Abstract
Colistin is increasingly used as the last-line therapy for infections caused by Gram-negative 'superbugs'. Although colistin neurotoxicity was reported in the literature, there has no data on its mechanism. In the present study, we examined the effect of colistin on primary chick neuron cells, which were treated with 0.83, 4.15 and 8.3μg/mL colistin for 6, 12 and 24h. Cell viability was evaluated with 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assays after exposure to colistin. Formation of reactive oxygen species (ROS), nuclear morphology, caspase-3 activity and internucleosomal DNA fragmentation were examined. The results showed that, compared with the control, no significant change was observed in cell viability, ROS formation and caspase-3 activity in cells treated for 6, 12 and 24h with 0.83μg/mL colistin. However, in the 4.15 and 8.3μg/mL colistin-treated groups, the viability of chick primary neurons significantly decreased at 12 and 24h, respectively; caspase-3 activities were significantly increased to 5.1 and 7.4 fold at 6h, more earlier than the changes of ROS, which was significant increased to 124.5% and 143.5% (P<0.01) of control at 12h, respectively. The apoptosis of neuron cells was revealed by both nuclear morphological observations and internucleosomal DNA fragmentation in the 4.15 and 8.3μg/mL colistin-treated groups at 6, 12 and 24h. Our data demonstrated that colistin can induce apoptosis in primary chick cortex neurons through caspase-3 activation, which may be contributed with ROS-dependent and independent mechanism.
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Affiliation(s)
- Chongshan Dai
- College of Veterinary Medicine, Northeast Agricultural University, 59 Mucai Street, Xiangfang District, Harbin 150030, PR China
| | - Dexian Zhang
- College of Veterinary Medicine, Northeast Agricultural University, 59 Mucai Street, Xiangfang District, Harbin 150030, PR China; College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang 110161, PR China
| | - Ruixia Gao
- College of Life Science, Northeast Agricultural University, 59 Mucai Street, Xiangfang District, Harbin 150030, PR China
| | - Xiuying Zhang
- College of Veterinary Medicine, Northeast Agricultural University, 59 Mucai Street, Xiangfang District, Harbin 150030, PR China
| | - Jian Li
- Facility for Anti-infective Drug Development and Innovation, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia.
| | - Jichang Li
- College of Veterinary Medicine, Northeast Agricultural University, 59 Mucai Street, Xiangfang District, Harbin 150030, PR China.
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Disruption in connexin-based communication is associated with intracellular Ca²⁺ signal alterations in astrocytes from Niemann-Pick type C mice. PLoS One 2013; 8:e71361. [PMID: 23977027 PMCID: PMC3744576 DOI: 10.1371/journal.pone.0071361] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Accepted: 06/27/2013] [Indexed: 01/12/2023] Open
Abstract
Reduced astrocytic gap junctional communication and enhanced hemichannel activity were recently shown to increase astroglial and neuronal vulnerability to neuroinflammation. Moreover, increasing evidence suggests that neuroinflammation plays a pivotal role in the development of Niemann-Pick type C (NPC) disease, an autosomal lethal neurodegenerative disorder that is mainly caused by mutations in the NPC1 gene. Therefore, we investigated whether the lack of NPC1 expression in murine astrocytes affects the functional state of gap junction channels and hemichannels. Cultured cortical astrocytes of NPC1 knock-out mice (Npc1−/−) showed reduced intercellular communication via gap junctions and increased hemichannel activity. Similarly, astrocytes of newborn Npc1−/− hippocampal slices presented high hemichannel activity, which was completely abrogated by connexin 43 hemichannel blockers and was resistant to inhibitors of pannexin 1 hemichannels. Npc1−/− astrocytes also showed more intracellular Ca2+ signal oscillations mediated by functional connexin 43 hemichannels and P2Y1 receptors. Therefore, Npc1−/− astrocytes present features of connexin based channels compatible with those of reactive astrocytes and hemichannels might be a novel therapeutic target to reduce neuroinflammation in NPC disease.
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Increased Expression of RhoA in Epithelium and Smooth Muscle of Obese Mouse Models: Implications for Isoprenoid Control of Airway Smooth Muscle and Fibroblasts. J Allergy (Cairo) 2013; 2013:740973. [PMID: 23840226 PMCID: PMC3693156 DOI: 10.1155/2013/740973] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Revised: 04/22/2013] [Accepted: 05/21/2013] [Indexed: 01/16/2023] Open
Abstract
The simultaneous rise in the prevalence of asthma and obesity has prompted epidemiologic studies that establish obesity as a risk factor for asthma. The alterations in cell signaling that explain this link are not well understood and warrant investigation so that therapies that target this asthma phenotype can be developed. We identified a significant increase in expression of the small GTPase RhoA in nasal epithelial cells and tracheal smooth muscle cells from leptin-deficient (ob/ob) mice compared to their wild-type counterparts. Since RhoA function is dependent on isoprenoid modification, we sought to determine the role of isoprenoid-mediated signaling in regulating the viability and proliferation of human airway smooth muscle cells (ASM) and normal human lung fibroblasts (NHLF). Inhibiting isoprenoid signaling with mevastatin significantly decreased the viability of ASM and NHLF. This inhibition was reversed by geranylgeranyl pyrophosphate (GGPP), but not farnesyl pyrophosphate (FPP), suggesting specificity to the Rho GTPases. Conversely, increasing isoprenoid synthesis significantly increased ASM proliferation and RhoA protein expression. RhoA expression is inherently increased in airway tissue from ob/ob mice, and obesity-entrained alterations in this pathway may make it a novel therapeutic target for treating airway disease in the obese population.
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Dai C, Zhang D, Li J, Li J. Effect of colistin exposure on calcium homeostasis and mitochondria functions in chick cortex neurons. Toxicol Mech Methods 2013. [DOI: 10.3109/15376516.2012.754533] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Amritraj A, Wang Y, Revett TJ, Vergote D, Westaway D, Kar S. Role of cathepsin D in U18666A-induced neuronal cell death: potential implication in Niemann-Pick type C disease pathogenesis. J Biol Chem 2012; 288:3136-52. [PMID: 23250759 DOI: 10.1074/jbc.m112.412460] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cathepsin D is an aspartyl protease that plays a crucial role in normal cellular functions and in a variety of neurodegenerative disorders, including Niemann-Pick type C (NPC) disease, which is characterized by intracellular accumulation of cholesterol and glycosphingolipids in many tissues, including the brain. There is evidence that the level and activity of cathepsin D increased markedly in vulnerable neurons in NPC pathology, but its involvement in neurodegeneration remains unclear. In the present study, using mouse hippocampal cultured neurons, we evaluated the significance of cathepsin D in toxicity induced by U18666A, a class II amphiphile, which triggers cell death by impairing the trafficking of cholesterol, as observed in NPC pathology. Our results showed that U18666A-mediated toxicity is accompanied by an increase in cathepsin D mRNA and enzyme activity but a decrease in the total peptide content. The cytosolic level of cathepsin D, on the other hand, was increased along with cytochrome c and activated caspase-3 in U18666A-treated neurons. The cathepsin D inhibitor, pepstatin A, partially protected neurons against toxicity by attenuating these signaling mechanisms. Additionally, down-regulation of cathepsin D level prevented, whereas overexpression of the protease increased, vulnerability of cultured N2a cells to U18666A-induced toxicity. We also showed that extracellular cathepsin D from U18666A-treated neurons or application of exogenous enzyme can induce neurotoxicity by activating the autophagic pathway. These results suggest that increased release/activation of cathepsin D can trigger neurodegeneration and possibly development of NPC pathology. Thus, targeting cathepsin D level/activity may provide a new therapeutic opportunity for the treatment of NPC pathology.
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Affiliation(s)
- Asha Amritraj
- Department of Psychiatry, Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta T6G 2M8, Canada
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Walterfang M, Chien YH, Imrie J, Rushton D, Schubiger D, Patterson MC. Dysphagia as a risk factor for mortality in Niemann-Pick disease type C: systematic literature review and evidence from studies with miglustat. Orphanet J Rare Dis 2012; 7:76. [PMID: 23039766 PMCID: PMC3552828 DOI: 10.1186/1750-1172-7-76] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2012] [Accepted: 09/24/2012] [Indexed: 02/06/2023] Open
Abstract
Niemann-Pick disease type C (NP-C) is a rare neurovisceral disease characterised by progressive neurological deterioration and premature death, and has an estimated birth incidence of 1:120,000. Mutations in the NPC1 gene (in 95% of cases) and the NPC2 gene (in approximately 4% of cases) give rise to impaired intracellular lipid metabolism in a number of tissues, including the brain. Typical neurological manifestations include vertical supranuclear gaze palsy, saccadic eye movement abnormalities, cerebellar ataxia, dystonia, dysmetria, dysphagia and dysarthria. Oropharyngeal dysphagia can be particularly problematic as it can often lead to food or fluid aspiration and subsequent pneumonia. Epidemiological data suggest that bronchopneumonia subsequent to food or fluid aspiration is a major cause of mortality in NP-C and other neurodegenerative disorders. These findings indicate that a therapy capable of improving or stabilising swallowing function might reduce the risk of aspiration pneumonia, and could have a positive impact on patient survival. Miglustat, currently the only approved disease-specific therapy for NP-C in children and adults, has been shown to stabilise key neurological manifestations in NP-C, including dysphagia. In this article we present findings from a systematic literature review of published data on bronchopneumonia/aspiration pneumonia as a cause of death, and on the occurrence of dysphagia in NP-C and other neurodegenerative diseases. We then examine the potential links between dysphagia, aspiration, pneumonia and mortality with a view to assessing the possible effect of miglustat on patient lifespan.
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Affiliation(s)
- Mark Walterfang
- Royal Melbourne Hospital and Melbourne Neuropsychiatry Centre, Melbourne 3050, Australia
| | - Yin-Hsiu Chien
- Departments of Paediatrics and Medical Genetics, National Taiwan University Hospital, Taipei, Taiwan
| | | | - Derren Rushton
- Actelion Pharmaceuticals Pty Ltd, New South Wales, Australia
| | - Danielle Schubiger
- Royal Melbourne Hospital and Melbourne Neuropsychiatry Centre, Melbourne 3050, Australia
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β-amyloid inhibits protein prenylation and induces cholesterol sequestration by impairing SREBP-2 cleavage. J Neurosci 2012; 32:6490-500. [PMID: 22573671 DOI: 10.1523/jneurosci.0630-12.2012] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Accumulation of β-amyloid (Aβ) inside brain neurons is an early and crucial event in Alzheimer's disease (AD). Studies in brains of AD patients and mice models of AD suggested that cholesterol homeostasis is altered in neurons that accumulate Aβ. Here we directly investigated the role of intracellular oligomeric Aβ(42) (oAβ(42)) in neuronal cholesterol homeostasis. We report that oAβ(42) induces cholesterol sequestration without increasing cellular cholesterol mass. Several features of AD, such as endosomal abnormalities, brain accumulation of Aβ and neurofibrillary tangles, and influence of apolipoprotein E genotype, are also present in Niemann-Pick type C, a disease characterized by impairment of intracellular cholesterol trafficking. These common features and data presented here suggest that a pathological mechanism involving abnormal cholesterol trafficking could take place in AD. Cholesterol sequestration in Aβ-treated neurons results from impairment of intracellular cholesterol trafficking secondary to inhibition of protein prenylation. oAβ(42) reduces sterol regulatory element-binding protein-2 (SREBP-2) cleavage, causing decrease of protein prenylation. Inhibition of protein prenylation represents a mechanism of oAβ(42)-induced neuronal death. Supply of the isoprenoid geranylgeranyl pyrophosphate to oAβ(42)-treated neurons recovers normal protein prenylation, reduces cholesterol sequestration, and prevents Aβ-induced neurotoxicity. Significant to AD, reduced levels of protein prenylation are present in the cerebral cortex of the TgCRND8 mouse model. In conclusion, we demonstrate a significant inhibitory effect of Aβ on protein prenylation and identify SREBP-2 as a target of oAβ(42), directly linking Aβ to cholesterol homeostasis impairment.
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Posse de Chaves E. Reciprocal regulation of cholesterol and beta amyloid at the subcellular level in Alzheimer's disease. Can J Physiol Pharmacol 2012; 90:753-64. [PMID: 22626060 DOI: 10.1139/y2012-076] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Since the discovery that apolipoprotein E, a cholesterol transport protein, is a major risk factor for Alzheimer's disease (AD) development, there has been a remarkable interest in understanding the many facets of the relationship between cholesterol and AD. Several lines of evidence have demonstrated the importance of cholesterol in amyloid beta peptide (Aβ) production and metabolism, as well as the involvement of Aβ in cholesterol homeostasis. The emerging picture is complex and still incomplete. This review discusses findings that indicate that a reciprocal regulation exists between Aβ and cholesterol at the subcellular level. The pathological impact of such regulation is highlighted.
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Affiliation(s)
- Elena Posse de Chaves
- Department of Pharmacology, 9-31 Medical Sciences Building, University of Alberta, Edmonton, AB T6G 2H7, Canada.
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Lhoták S, Sood S, Brimble E, Carlisle RE, Colgan SM, Mazzetti A, Dickhout JG, Ingram AJ, Austin RC. ER stress contributes to renal proximal tubule injury by increasing SREBP-2-mediated lipid accumulation and apoptotic cell death. Am J Physiol Renal Physiol 2012; 303:F266-78. [PMID: 22573382 DOI: 10.1152/ajprenal.00482.2011] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Renal proximal tubule injury is induced by agents/conditions known to cause endoplasmic reticulum (ER) stress, including cyclosporine A (CsA), an immunosuppressant drug with nephrotoxic effects. However, the underlying mechanism by which ER stress contributes to proximal tubule cell injury is not well understood. In this study, we report lipid accumulation, sterol regulatory element-binding protein-2 (SREBP-2) expression, and ER stress in proximal tubules of kidneys from mice treated with the classic ER stressor tunicamycin (Tm) or in human renal biopsy specimens showing CsA-induced nephrotoxicity. Colocalization of ER stress markers [78-kDa glucose regulated protein (GRP78), CHOP] with SREBP-2 expression and lipid accumulation was prominent within the proximal tubule cells exposed to Tm or CsA. Prolonged ER stress resulted in increased apoptotic cell death of lipid-enriched proximal tubule cells with colocalization of GRP78, SREBP-2, and Ca(2+)-independent phospholipase A(2) (iPLA(2)β), an SREBP-2 inducible gene with proapoptotic characteristics. In cultured HK-2 human proximal tubule cells, CsA- and Tm-induced ER stress caused lipid accumulation and SREBP-2 activation. Furthermore, overexpression of SREBP-2 or activation of endogenous SREBP-2 in HK-2 cells stimulated apoptosis. Inhibition of SREBP-2 activation with the site-1-serine protease inhibitor AEBSF prevented ER stress-induced lipid accumulation and apoptosis. Overexpression of the ER-resident chaperone GRP78 attenuated ER stress and inhibited CsA-induced SREBP-2 expression and lipid accumulation. In summary, our findings suggest that ER stress-induced SREBP-2 activation contributes to renal proximal tubule cell injury by dysregulating lipid homeostasis.
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Affiliation(s)
- Sárka Lhoták
- Hamilton Centre for Kidney Research, St. Joseph's Healthcare Hamilton, 50 Charlton Ave. East, Hamilton, Ontario, Canada
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Seo Y, Yang SR, Kim HS, Yu KR, Shin Y, Kang SK, Kang KS. JNK Activation by Up-Regulation of iNOS on Cholesterol Accumulation Limits Neurogenesis and Induces Region-Specific DNA Damage Responses in the Subventricular Zone of NPC Mice. Antioxid Redox Signal 2012:120410100912001. [PMID: 22384812 DOI: 10.1089/ars.2011.4301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Abstract Aims: We explore the region-specific impact of nitric oxide (NO) on adult neural stem cell (aNSC) niches with regard to neurogenesis and NSC damage and investigate the underlying mechanisms in Niemann-Pick disease type C (NPC) mice. Results: Among the two anatomical stem-cell niches of the brain, subventricular zone (SVZ)-derived aNSCs enhanced c-Jun N-terminal kinase (JNK) activity because of excessive NO production by the cholesterol accumulation. Activated JNK interacts with γH2AX, a marker for DNA damage; however, almost none of the aNSCs in the dentate gyrus (DG) showed either JNK signaling activation or abundant DNA damage. SVZ-derived aNSCs were protected from DNA damage by the treatment of Nω-nitro-L-arginine methyl ester (L-NAME), a NO synthase (NOS) inhibitor, both in vitro and in vivo. We also observed that U18666A, an inducer of cholesterol accumulation, increased inducible NOS expression, JNK activation, and DNA damage in the wild type (WT)-aNSCs. Interestingly, we found that endogenous cholesterol efflux transporters and their regulator were less activated in the SVZ than in the DG, in both WT and NPC mice. This result explains the high vulnerability of SVZ-derived aNSCs to the cholesterol imbalance as observed in NPC mice. Innovation and Conclusion: In this study, we demonstrated that the SVZ-derived aNSCs might be major targets of NPC. Significantly, aNSCs showed different responses depending on their anatomical origins due to dissimilarities in their cholesterol transporting system and NO-dependent JNK activation. These findings can contribute to the understanding of the region-specific nature of the two SVZ and DG neurogenic niches. Antioxid. Redox Signal. 00, 000-000.
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Affiliation(s)
- Yoojin Seo
- 1 Adult Stem Cell Research Center, College of Veterinary Medicine, Seoul National University , Seoul, Republic of Korea
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Cabeza C, Figueroa A, Lazo OM, Galleguillos C, Pissani C, Klein A, Gonzalez-Billault C, Inestrosa NC, Alvarez AR, Zanlungo S, Bronfman FC. Cholinergic abnormalities, endosomal alterations and up-regulation of nerve growth factor signaling in Niemann-Pick type C disease. Mol Neurodegener 2012; 7:11. [PMID: 22458984 PMCID: PMC3395862 DOI: 10.1186/1750-1326-7-11] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Accepted: 03/29/2012] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Neurotrophins and their receptors regulate several aspects of the developing and mature nervous system, including neuronal morphology and survival. Neurotrophin receptors are active in signaling endosomes, which are organelles that propagate neurotrophin signaling along neuronal processes. Defects in the Npc1 gene are associated with the accumulation of cholesterol and lipids in late endosomes and lysosomes, leading to neurodegeneration and Niemann-Pick type C (NPC) disease. The aim of this work was to assess whether the endosomal and lysosomal alterations observed in NPC disease disrupt neurotrophin signaling. As models, we used i) NPC1-deficient mice to evaluate the central cholinergic septo-hippocampal pathway and its response to nerve growth factor (NGF) after axotomy and ii) PC12 cells treated with U18666A, a pharmacological cellular model of NPC, stimulated with NGF. RESULTS NPC1-deficient cholinergic cells respond to NGF after axotomy and exhibit increased levels of choline acetyl transferase (ChAT), whose gene is under the control of NGF signaling, compared to wild type cholinergic neurons. This finding was correlated with increased ChAT and phosphorylated Akt in basal forebrain homogenates. In addition, we found that cholinergic neurons from NPC1-deficient mice had disrupted neuronal morphology, suggesting early signs of neurodegeneration. Consistently, PC12 cells treated with U18666A presented a clear NPC cellular phenotype with a prominent endocytic dysfunction that includes an increased size of TrkA-containing endosomes and reduced recycling of the receptor. This result correlates with increased sensitivity to NGF, and, in particular, with up-regulation of the Akt and PLC-γ signaling pathways, increased neurite extension, increased phosphorylation of tau protein and cell death when PC12 cells are differentiated and treated with U18666A. CONCLUSIONS Our results suggest that the NPC cellular phenotype causes neuronal dysfunction through the abnormal up-regulation of survival pathways, which causes the perturbation of signaling cascades and anomalous phosphorylation of the cytoskeleton.
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Affiliation(s)
- Carolina Cabeza
- Physiology Department, Millennium Nucleus in Regenerative Biology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
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Ordonez MP, Roberts EA, Kidwell CU, Yuan SH, Plaisted WC, Goldstein LSB. Disruption and therapeutic rescue of autophagy in a human neuronal model of Niemann Pick type C1. Hum Mol Genet 2012; 21:2651-62. [PMID: 22437840 DOI: 10.1093/hmg/dds090] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
An unresolved issue about many neurodegenerative diseases is why neurons are particularly sensitive to defects in ubiquitous cellular processes. One example is Niemann Pick type C1, caused by defects in cholesterol trafficking in all cells, but where neurons are preferentially damaged. Understanding this selective failure is limited by the difficulty in obtaining live human neurons from affected patients. To solve this problem, we generated neurons with decreased function of NPC1 from human embryonic stem cells and used them to test the hypothesis that defective cholesterol handling leads to enhanced pathological phenotypes in neurons. We found that human NPC1 neurons have strong spontaneous activation of autophagy, and, contrary to previous reports in patient fibroblasts, a block of autophagic progression leading to defective mitochondrial clearance. Mitochondrial fragmentation is an exceptionally severe phenotype in NPC1 neurons compared with fibroblasts, causing abnormal accumulation of mitochondrial proteins. Contrary to expectation, these abnormal phenotypes were rescued by treatment with the autophagy inhibitor 3-methyladenine and by treatment with the potential therapeutic cyclodextrin, which mobilizes cholesterol from the lysosomal compartment. Our findings suggest that neurons are especially sensitive to lysosomal cholesterol accumulation because of autophagy disruption and accumulation of fragmented mitochondria, thus defining a new route to effective drug development for NPC1 disease.
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Affiliation(s)
- M Paulina Ordonez
- Department of Cellular and Molecular Medicine, Howard Hughes Medical Institute, University of California San Diego, La Jolla, CA 92093, USA
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Lange Y, Ye J, Steck TL. Activation mobilizes the cholesterol in the late endosomes-lysosomes of Niemann Pick type C cells. PLoS One 2012; 7:e30051. [PMID: 22276143 PMCID: PMC3262792 DOI: 10.1371/journal.pone.0030051] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Accepted: 12/12/2011] [Indexed: 11/18/2022] Open
Abstract
A variety of intercalating amphipaths increase the chemical activity of plasma membrane cholesterol. To test whether intracellular cholesterol can be similarly activated, we examined NPC1 and NPC2 fibroblasts, since they accumulate large amounts of cholesterol in their late endosomes and lysosomes (LE/L). We gauged the mobility of intracellular sterol from its appearance at the surface of the intact cells, as determined by its susceptibility to cholesterol oxidase and its isotope exchange with extracellular 2-(hydroxypropyl)-β-cyclodextrin-cholesterol. The entire cytoplasmic cholesterol pool in these cells was mobile, exchanging with the plasma membrane with an apparent half-time of ∼3–4 hours, ∼4–5 times slower than that for wild type human fibroblasts (half-time ∼0.75 hours). The mobility of the intracellular cholesterol was increased by the membrane-intercalating amphipaths chlorpromazine and 1-octanol. Chlorpromazine also promoted the net transfer of LE/L cholesterol to serum and cyclodextrin. Surprisingly, the mobility of LE/L cholesterol was greatly stimulated by treating intact NPC cells with glutaraldehyde or formaldehyde. Similar effects were seen with wild type fibroblasts in which the LE/L cholesterol pool had been expanded using U18666A. We also showed that the cholesterol in the intracellular membranes of fixed wild-type fibroblasts was mobile; it was rapidly oxidized by cholesterol oxidase and was rapidly replenished by exogenous sterol. We conclude that a) the cholesterol in NPC cells can exit the LE/L (and the extensive membranous inclusions therein) over a few hours; b) this mobility is stimulated by the activation of the cholesterol with intercalating amphipaths; c) intracellular cholesterol is even more mobile in fixed cells; and d) amphipaths that activate cholesterol might be useful in treating NPC disease.
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Affiliation(s)
- Yvonne Lange
- Department of Pathology, Rush University Medical Center, Chicago, Illinois, United States of America.
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Nunes A, Pressey SNR, Cooper JD, Soriano S. Loss of amyloid precursor protein in a mouse model of Niemann-Pick type C disease exacerbates its phenotype and disrupts tau homeostasis. Neurobiol Dis 2011; 42:349-59. [PMID: 21303697 DOI: 10.1016/j.nbd.2011.01.028] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2010] [Revised: 01/05/2011] [Accepted: 01/28/2011] [Indexed: 10/18/2022] Open
Abstract
Niemann-Pick type C disease (NPC) is a lysosomal storage disorder which, at the cellular level, shows amyloid Aβ and tau pathologies comparable to those seen in the AD brain. Here, we have investigated, in a mouse model of NPC, the impact of removing the source of Aβ, namely APP, on the disease phenotype and on the expression levels and phosphorylation patterns of tau. We reasoned that removing APP from the NPC brain might help to unveil its impact on the disease phenotype and shed light on the mechanisms governing the interaction, both physiological and pathological, between APP function and tau homeostasis, at least in NPC. We show that, unexpectedly, loss of APP in NPC mice leads to poorer neuromuscular coordination and cumulative survival rates; exacerbation of their cholesterol abnormalities; higher levels of astrocytosis and dysregulation of tau homeostasis. Our results are consistent with a mechanism of neurodegeneration in the NPC and AD brains in which cholesterol dysregulation is a key early pathogenic event affecting tau homeostasis in parallel with, and independently of, amyloid accumulation.
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Affiliation(s)
- Ana Nunes
- Department of Neuroscience, MRC Centre for Neurodegeneration Research, King's College London, Institute of Psychiatry, De Crespigny Park, London SE5 8AF, UK
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Pfeifer T, Buchebner M, Chandak PG, Patankar J, Kratzer A, Obrowsky S, Rechberger GN, Kadam RS, Kompella UB, Kostner GM, Kratky D, Levak-Frank S. Synthetic LXR agonist suppresses endogenous cholesterol biosynthesis and efficiently lowers plasma cholesterol. Curr Pharm Biotechnol 2011; 12:285-92. [PMID: 21190543 PMCID: PMC3163291 DOI: 10.2174/138920111794295774] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Accepted: 06/13/2010] [Indexed: 11/22/2022]
Abstract
The liver X receptors (LXRs) are key regulators of genes involved in cholesterol homeostasis. Natural ligands and activators of LXRs are oxysterols. Numerous steroidal and non-steroidal synthetic LXR ligands are under development as potential drugs for individuals suffering from lipid disorders. N,N-dimethyl-3β-hydroxycholenamide (DMHCA) is a steroidal ligand of LXRs that exerts anti-atherogenic effects in apolipoprotein E-deficient mice without causing negative side effects such as liver steatosis or hypertriglyceridemia. In this report, we investigated the consequences of DMHCA treatment on cholesterol homeostasis in vivo and in vitro. Despite its hydrophobicity, DMHCA is readily absorbed by C57BL/6 mice and taken up by intestinal cells, the lung, heart and kidneys, but is undetectable in the brain. DMHCA significantly reduces cholesterol absorption and uptake in duodenum and jejunum of the small intestine and in turn leads to a reduction of plasma cholesterol by 24%. The most striking finding of this study is that DMHCA inhibited the enzyme 3β-hydroxysterol-Δ24-reductase resulting in an accumulation of desmosterol in the plasma and in feces. Thus, the reduction of plasma cholesterol was due to a block in the final step of cholesterol biosynthesis. Taken together, DMHCA is an interesting compound with properties distinct from other LXR ligands and might be used to study desmosterol-mediated effects in cells and tissues.
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Affiliation(s)
- Thomas Pfeifer
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, 8010 Graz, Austria
| | - Marlene Buchebner
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, 8010 Graz, Austria
| | - Prakash G. Chandak
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, 8010 Graz, Austria
| | - Jay Patankar
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, 8010 Graz, Austria
| | - Adelheid Kratzer
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, 8010 Graz, Austria
| | - Sascha Obrowsky
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, 8010 Graz, Austria
| | | | - Rajendra S. Kadam
- Department of Pharmaceutical Sciences, University of Colorado, Denver, CO, USA
| | - Uday B. Kompella
- Department of Pharmaceutical Sciences, University of Colorado, Denver, CO, USA
| | - Gerhard M. Kostner
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, 8010 Graz, Austria
| | - Dagmar Kratky
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, 8010 Graz, Austria
| | - Sanja Levak-Frank
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, 8010 Graz, Austria
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Kodam A, Maulik M, Peake K, Amritraj A, Vetrivel KS, Thinakaran G, Vance JE, Kar S. Altered levels and distribution of amyloid precursor protein and its processing enzymes in Niemann-Pick type C1-deficient mouse brains. Glia 2010; 58:1267-81. [PMID: 20607864 PMCID: PMC2914615 DOI: 10.1002/glia.21001] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Niemann-Pick type C (NPC) disease is an autosomal recessive neurodegenerative disorder characterized by intracellular accumulation of cholesterol and glycosphingolipids in many tissues including the brain. The disease is caused by mutations of either NPC1 or NPC2 gene and is accompanied by a severe loss of neurons in the cerebellum, but not in the hippocampus. NPC pathology exhibits some similarities with Alzheimer's disease, including increased levels of amyloid beta (Abeta)-related peptides in vulnerable brain regions, but very little is known about the expression of amyloid precursor protein (APP) or APP secretases in NPC disease. In this article, we evaluated age-related alterations in the level/distribution of APP and its processing enzymes, beta- and gamma-secretases, in the hippocampus and cerebellum of Npc1(-/-) mice, a well-established model of NPC pathology. Our results show that levels and expression of APP and beta-secretase are elevated in the cerebellum prior to changes in the hippocampus, whereas gamma-secretase components are enhanced in both brain regions at the same time in Npc1(-/-) mice. Interestingly, a subset of reactive astrocytes in Npc1(-/-) mouse brains expresses high levels of APP as well as beta- and gamma-secretase components. Additionally, the activity of beta-secretase is enhanced in both the hippocampus and cerebellum of Npc1(-/-) mice at all ages, while the level of C-terminal APP fragments is increased in the cerebellum of 10-week-old Npc1(-/-) mice. These results, taken together, suggest that increased level and processing of APP may be associated with the development of pathology and/or degenerative events observed in Npc1(-/-) mouse brains.
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Affiliation(s)
- A Kodam
- Department of Psychiatry, Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, Canada
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Liu HP, Wu CC, Kao HY, Huang YC, Liang Y, Chen CC, Yu JS, Chang YS. Proteome-wide dysregulation by PRA1 depletion delineates a role of PRA1 in lipid transport and cell migration. Mol Cell Proteomics 2010; 10:M900641MCP200. [PMID: 20592422 DOI: 10.1074/mcp.m900641-mcp200] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have previously identified prenylated Rab acceptor 1 (PRA1) as a novel cellular interacting partner for Epstein-Barr virus-encoded oncoprotein, latent membrane protein 1 (LMP1). The intracellular trafficking and full signaling of LMP1 requires its interaction with PRA1. To further explore the role of PRA1 in Epstein-Barr virus-associated nasopharyngeal carcinoma (NPC) cells, we generated several PRA1-knockdown cell clones, which exhibited altered cell morphology and increased cell motility. We identified proteins differentially expressed in the knockdown clones by means of isobaric mass tags labeling coupled with multidimensional liquid chromatography-mass spectrometry. We validated a panel of proteins, which showed consistent up-regulation in PRA1-knockdown clones and participated in regulating lipid homeostasis and cell migration. Immunofluorescence staining further revealed altered localization of these proteins and accumulation of intracellular cholesterol in PRA1-knockdown clones. These effects were phenocopied by treatment with a cholesterol transport inhibitor, U18666A. Moreover, overexpressed PRA1 was able to alleviate the dysregulation of these affected proteins either from PRA1 knockdown or U18666A treatment, implying a role for PRA1 in regulating the levels of these affected proteins in response to altered cholesterol homeostasis. We further demonstrated that LMP1 expression caused PRA1 sequestration in NPC cells, leading to a consequence reminiscent of PRA1 knockdown. Finally, the immunohistochemistry showed a physiological relevance of the PRA1-associated proteome-wide changes in NPC biopsy tissues. In sum, our findings delineated novel roles of PRA1 in lipid transport and cell migration, and provided additional insights into the molecular basis of NPC morphogenesis, namely a consequence of LMP1-PRA1 interaction.
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Affiliation(s)
- Hao-Ping Liu
- Molecular Medicine Research Center, Department of Medical Biotechnology and Laboratory Science, Graduate Institute of Biomedical Sciences, Chang Gung University, Tao-Yuan, Taiwan
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Strauss K, Goebel C, Runz H, Möbius W, Weiss S, Feussner I, Simons M, Schneider A. Exosome secretion ameliorates lysosomal storage of cholesterol in Niemann-Pick type C disease. J Biol Chem 2010; 285:26279-88. [PMID: 20554533 DOI: 10.1074/jbc.m110.134775] [Citation(s) in RCA: 186] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Niemann-Pick type C1 disease is an autosomal-recessive lysosomal storage disorder. Loss of function of the npc1 gene leads to abnormal accumulation of free cholesterol and sphingolipids within the late endosomal and lysosomal compartments resulting in progressive neurodegeneration and dysmyelination. Here, we show that oligodendroglial cells secrete cholesterol by exosomes when challenged with cholesterol or U18666A, which induces late endosomal cholesterol accumulation. Up-regulation of exosomal cholesterol release was also observed after siRNA-mediated knockdown of NPC1 and in fibroblasts derived from NPC1 patients and could be reversed by expression of wild-type NPC1. We provide evidence that exosomal cholesterol secretion depends on the presence of flotillin. Our findings indicate that exosomal release of cholesterol may serve as a cellular mechanism to partially bypass the traffic block that results in the toxic lysosomal cholesterol accumulation in Niemann-Pick type C1 disease. Furthermore, we suggest that secretion of cholesterol by exosomes contributes to maintain cellular cholesterol homeostasis.
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Affiliation(s)
- Katrin Strauss
- Max-Planck-Institute for Experimental Medicine, Goettingen, Germany
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44
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Fan J, Rone MB, Papadopoulos V. Translocator protein 2 is involved in cholesterol redistribution during erythropoiesis. J Biol Chem 2009; 284:30484-97. [PMID: 19729679 PMCID: PMC2781603 DOI: 10.1074/jbc.m109.029876] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2009] [Revised: 08/17/2009] [Indexed: 12/11/2022] Open
Abstract
Translocator protein (TSPO) is an 18-kDa cholesterol- and drug-binding protein conserved from bacteria to humans. While surveying for Tspo-like genes, we identified its paralogous gene, Tspo2, encoding an evolutionarily conserved family of proteins that arose by gene duplications before the divergence of avians and mammals. Comparative analysis of Tspo1 and Tspo2 functions suggested that Tspo2 has become subfunctionalized, typical of duplicated genes, characterized by the loss of diagnostic drug ligand-binding but retention of cholesterol-binding properties, hematopoietic tissue- and erythroid cell-specific distribution, and subcellular endoplasmic reticulum and nuclear membrane localization. Expression of Tspo2 in erythroblasts is strongly correlated with the down-regulation of the enzymes involved in cholesterol biosynthesis. Overexpression of TSPO2 in erythroid cells resulted in the redistribution of intracellular free cholesterol, an essential step in nucleus expulsion during erythrocyte maturation. Taken together, these data identify the TSPO2 family of proteins as mediators of cholesterol redistribution-dependent erythroblast maturation during mammalian erythropoiesis.
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Affiliation(s)
- Jinjiang Fan
- From the Research Institute of the McGill University Health Center and the Departments of Medicine, Biochemistry, and Pharmacology and Therapeutics, McGill University, Montréal, Québec H3A 1A4, Canada
| | - Malena B. Rone
- From the Research Institute of the McGill University Health Center and the Departments of Medicine, Biochemistry, and Pharmacology and Therapeutics, McGill University, Montréal, Québec H3A 1A4, Canada
| | - Vassilios Papadopoulos
- From the Research Institute of the McGill University Health Center and the Departments of Medicine, Biochemistry, and Pharmacology and Therapeutics, McGill University, Montréal, Québec H3A 1A4, Canada
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Ha SD, Ham B, Mogridge J, Saftig P, Lin S, Kim SO. Cathepsin B-mediated autophagy flux facilitates the anthrax toxin receptor 2-mediated delivery of anthrax lethal factor into the cytoplasm. J Biol Chem 2009; 285:2120-9. [PMID: 19858192 DOI: 10.1074/jbc.m109.065813] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Anthrax lethal toxin (LeTx) is a virulence factor secreted by Bacillus anthracis and has direct cytotoxic effects on most cells once released into the cytoplasm. The cytoplasmic delivery of the proteolytically active component of LeTx, lethal factor (LF), is carried out by the transporter component, protective antigen, which interacts with either of two known surface receptors known as anthrax toxin receptor (ANTXR) 1 and 2. We found that the cytoplasmic delivery of LF by ANTXR2 was mediated by cathepsin B (CTSB) and required lysosomal fusion with LeTx-containing endosomes. Also, binding of protective antigen to ANXTR1 or -2 triggered autophagy, which facilitated the cytoplasmic delivery of ANTXR2-associated LF. We found that whereas cells treated with the membrane-permeable CTSB inhibitor CA074-Me- or CTSB-deficient cells had no defect in fusion of LC3-containing autophagic vacuoles with lysosomes, autophagic flux was significantly delayed. These results suggested that the ANTXR2-mediated cytoplasmic delivery of LF was enhanced by CTSB-dependent autophagic flux.
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Affiliation(s)
- Soon-Duck Ha
- Department of Microbiology and Immunology, Siebens-Drake Research Institute, University of Western Ontario, London, Ontario N6G2V4, Canada
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Rocha N, Kuijl C, van der Kant R, Janssen L, Houben D, Janssen H, Zwart W, Neefjes J. Cholesterol sensor ORP1L contacts the ER protein VAP to control Rab7-RILP-p150 Glued and late endosome positioning. ACTA ACUST UNITED AC 2009; 185:1209-25. [PMID: 19564404 PMCID: PMC2712958 DOI: 10.1083/jcb.200811005] [Citation(s) in RCA: 520] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Late endosomes (LEs) have characteristic intracellular distributions determined by their interactions with various motor proteins. Motor proteins associated to the dynactin subunit p150(Glued) bind to LEs via the Rab7 effector Rab7-interacting lysosomal protein (RILP) in association with the oxysterol-binding protein ORP1L. We found that cholesterol levels in LEs are sensed by ORP1L and are lower in peripheral vesicles. Under low cholesterol conditions, ORP1L conformation induces the formation of endoplasmic reticulum (ER)-LE membrane contact sites. At these sites, the ER protein VAP (VAMP [vesicle-associated membrane protein]-associated ER protein) can interact in trans with the Rab7-RILP complex to remove p150(Glued) and associated motors. LEs then move to the microtubule plus end. Under high cholesterol conditions, as in Niemann-Pick type C disease, this process is prevented, and LEs accumulate at the microtubule minus end as the result of dynein motor activity. These data explain how the ER and cholesterol control the association of LEs with motor proteins and their positioning in cells.
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Affiliation(s)
- Nuno Rocha
- Division of Cell Biology, The Netherlands Cancer Institute, 1066CX Amsterdam, Netherlands
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Zhang L, Sheng R, Qin Z. The lysosome and neurodegenerative diseases. Acta Biochim Biophys Sin (Shanghai) 2009; 41:437-45. [PMID: 19499146 DOI: 10.1093/abbs/gmp031] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
It has long been believed that the lysosome is an important digestive organelle. There is increasing evidence that the lysosome is also involved in pathogenesis of a variety of neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis. Abnormal protein degradation and deposition induced by lysosomal dysfunction may be the primary contributor to age-related neurodegeneration. In this review, the possible relationship between lysosome and various neurodegenerative diseases is described.
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Affiliation(s)
- Lisha Zhang
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Soochow University School of Medicine, Suzhou 215123, China
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48
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Cholesterol synthesis inhibitor U18666A and the role of sterol metabolism and trafficking in numerous pathophysiological processes. Lipids 2009; 44:477-87. [PMID: 19440746 DOI: 10.1007/s11745-009-3305-7] [Citation(s) in RCA: 169] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2008] [Accepted: 12/16/2008] [Indexed: 01/16/2023]
Abstract
The multiple actions of U18666A have enabled major discoveries in lipid research and contributed to understanding the pathophysiology of multiple diseases. This review describes these advances and the utility of U18666A as a tool in lipid research. Harry Rudney's recognition that U18666A inhibited oxidosqualene cyclase led him to discover a pathway for formation of polar sterols that he proved to be important regulators of 3-hydroxy-3-methyl-glutaryl coenzyme A reductase. Laura Liscum's recognition that U18666A inhibited the egress of cholesterol from late endosomes and lysosomes led to greatly improved perspective on the major pathways of intracellular cholesterol trafficking. The inhibition of cholesterol trafficking by U18666A mimicked the loss of functional Niemann-Pick type C protein responsible for NPC disease and thus provided a model for this disorder. U18666A subsequently became a tool for assessing the importance of molecular trafficking through the lysosomal pathway in other conditions such as atherosclerosis, Alzheimer's disease, and prion infections. U18666A also provided animal models for two important disorders: petite mal (absence) epilepsy and cataracts. This was the first chronic model of absence epilepsy. U18666A is also being used to address the role of oxidative stress in apoptosis. How can one molecule have so many effects? Perhaps because of its structure as an amphipathic cationic amine it can interact and inhibit diverse proteins. Restricting the availability of cholesterol for membrane formation through inhibition of cholesterol synthesis and intracellular trafficking could also be a mechanism for broadly affecting many processes. Another possibility is that through intercalation into membrane U18666A can alter membrane order and therefore the function of resident proteins. The similarity of the effects of natural and enantiomeric U18666A on cells and the capacity of intercalated U18666A to increase membrane order are arguments in favor of this possibility.
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Lange Y, Steck TL, Ye J, Lanier MH, Molugu V, Ory D. Regulation of fibroblast mitochondrial 27-hydroxycholesterol production by active plasma membrane cholesterol. J Lipid Res 2009; 50:1881-8. [PMID: 19401598 DOI: 10.1194/jlr.m900116-jlr200] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Side chain oxysterols are cholesterol derivatives thought to signal the abundance of cell cholesterol to homeostatic effector proteins. Here, we investigated how plasma membrane (PM) cholesterol might regulate 27-hydroxycholesterol (HC) biosynthesis in cultured fibroblasts. We showed that PM cholesterol was a major substrate for 27-HC production. Biosynthesis commenced within minutes of loading depleted cells with cholesterol, concurrent with the rapid inactivation of hydroxy-3-methylglutaryl CoA reductase (HMGR). 27-HC production rose approximately 30-fold in normal and Niemann-Pick C1 fibroblasts when PM cholesterol was increased by approximately 60%. 27-HC production was also stimulated by 1-octanol, which displaces PM cholesterol from its phospholipid complexes and thereby increases its activity (escape tendency) and elevates its intracellular abundance. Conversely, lysophosphatidylserine and U18666A inhibited 27-HC biosynthesis and the inactivation of HMGR, presumably by reducing the activity of PM cholesterol and, therefore, its circulation to mitochondria. We conclude that, in this in vitro system, excess (active) PM cholesterol rapidly reaches mitochondria where, as the rate-limiting substrate, it stimulates 27-HC biosynthesis. The oxysterol product then promotes the rapid degradation of HMGR, along with other homeostatic effects. The regulation of 27-HC production by the active excess of PM cholesterol can thus provide a feedback mechanism in the homeostasis of PM cholesterol.
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Affiliation(s)
- Yvonne Lange
- Department of Pathology, Rush University Medical Center, Chicago, IL 60612, USA.
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50
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Parent N, Winstall E, Beauchemin M, Paquet C, Poirier GG, Bertrand R. Proteomic analysis of enriched lysosomes at early phase of camptothecin-induced apoptosis in human U-937 cells. J Proteomics 2009; 72:960-73. [PMID: 19393779 DOI: 10.1016/j.jprot.2009.04.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2009] [Revised: 03/24/2009] [Accepted: 04/18/2009] [Indexed: 11/26/2022]
Abstract
A lysosomal pathway, characterized by partial rupture or labilization of lysosomal membranes and cathepsin activation, is evoked during camptothecin-induced apoptosis in human cancer cells, including human histiocytic lymphoma U-937 cells. These lysosomal events begin rapidly and simultaneously with mitochondrial permeabilization and caspase activation within 3 h after drug treatment. In this study, comparative and quantitative proteome analyses were performed to identify early changes in lysosomal protein expression/localization from U-937 cells undergoing apoptosis. In 2 independent experiments, among a total of more than 538 proteins putatively identified and quantitated by iTRAQ isobaric labeling and LC-ESI-MS/MS, 18 proteins were found to be upregulated and 9 downregulated in lysosomes purified from early apoptotic compared to control cells. Protein expression was validated by Western blotting on enriched lysosome fractions, and protein localization confirmed by fluorescence confocal microscopy of representative protein candidates, whose functions are associated with lysosomal membrane fluidity and dynamics. These include sterol-4-alpha-carboxylate 3-dehydrogenase (NSDHL), prosaposin (PSAP) and protein kinase C delta (PKC-delta). This comparative proteome analysis provides the basis for novel hypothesis and rationale functional experimentation, where the 3 validated candidate proteins are associated with lysosomal membrane fluidity and dynamics, particularly cholesterol, sphingolipid and glycosphingolipid metabolism.
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Affiliation(s)
- Nicolas Parent
- Centre de recherche, Centre hospitalier de l'Université of Montréal (CHUM), Hôpital Notre-Dame and Institut du cancer de Montréal, Montréal (QC), Canada
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