1
|
Javanshad R, Nguyen TTA, Azaria RD, Li W, Edmison D, Gong LW, Gowrishankar S, Lieberman AP, Schultz ML, Cologna SM. Endogenous Protein-Protein Interaction Network of the NPC Cholesterol Transporter 1 in the Cerebral Cortex. J Proteome Res 2024; 23:3174-3187. [PMID: 38686625 DOI: 10.1021/acs.jproteome.3c00788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
NPC intracellular cholesterol transporter 1 (NPC1) is a multipass, transmembrane glycoprotein mostly recognized for its key role in facilitating cholesterol efflux. Mutations in the NPC1 gene result in Niemann-Pick disease, type C (NPC), a fatal, lysosomal storage disease. Due to the progressively expanding implications of NPC1-related disorders, we investigated endogenous NPC1 protein-protein interactions in the mouse cortex and human-derived iPSCs neuronal models of the disease through coimmunoprecipitation-coupled with LC-MS based proteomics. The current study investigated protein-protein interactions specific to the wild-type and the most prevalent NPC1 mutation (NPC1I1061T) while filtering out any protein interactor identified in the Npc1-/- mouse model. Additionally, the results were matched across the two species to map the parallel interactome of wild-type and mutant NPC1I1061T. Most of the identified wild-type NPC1 interactors were related to cytoskeleton organization, synaptic vesicle activity, and translation. We found many putative NPC1 interactors not previously reported, including two SCAR/WAVE complex proteins that regulate ARP 2/3 complex actin nucleation and multiple membrane proteins important for neuronal activity at synapse. Moreover, we identified proteins important in trafficking specific to wild-type and mutant NPC1I1061T. Together, the findings are essential for a comprehensive understanding of NPC1 biological functions in addition to its classical role in sterol efflux.
Collapse
Affiliation(s)
- Roshan Javanshad
- Department of Chemistry, University of Illinois Chicago, Chicago, Illinois 60607, United States
| | - Thu T A Nguyen
- Department of Chemistry, University of Illinois Chicago, Chicago, Illinois 60607, United States
| | - Ruth D Azaria
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan 48109, United States
| | - Wenping Li
- Department of Chemistry, University of Illinois Chicago, Chicago, Illinois 60607, United States
| | - Daisy Edmison
- Department of Anatomy and Cell Biology, University of Illinois Chicago, Chicago, Illinois 60612, United States
| | - Liang-Wei Gong
- Department of Biological Sciences, University of Illinois Chicago, Chicago, Illinois 60607, United States
| | - Swetha Gowrishankar
- Department of Anatomy and Cell Biology, University of Illinois Chicago, Chicago, Illinois 60612, United States
| | - Andrew P Lieberman
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan 48109, United States
| | - Mark L Schultz
- Stead Family Department of Pediatrics, University of Iowa, Iowa City, Iowa 52242, United States
| | - Stephanie M Cologna
- Department of Chemistry, University of Illinois Chicago, Chicago, Illinois 60607, United States
| |
Collapse
|
2
|
Su H, Zhu L, Su L, Li M, Wang R, Zhu J, Chen Y, Chen T. Impact of miR-29c-3p in the Nucleus Accumbens on Methamphetamine-Induced Behavioral Sensitization and Neuroplasticity-Related Proteins. Int J Mol Sci 2024; 25:942. [PMID: 38256016 PMCID: PMC10815255 DOI: 10.3390/ijms25020942] [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: 11/17/2023] [Revised: 12/26/2023] [Accepted: 01/09/2024] [Indexed: 01/24/2024] Open
Abstract
Methamphetamine (METH) abuse inflicts both physical and psychological harm. While our previous research has established the regulatory role of miR-29c-3p in behavior sensitization, the underlying mechanisms and target genes remain incompletely understood. In this study, we employed the isobaric tags for relative and absolute quantitation (iTRAQ) technique in conjunction with Ingenuity pathway analysis (IPA) to probe the putative molecular mechanisms of METH sensitization through miR-29c-3p inhibition. Through a microinjection of AAV-anti-miR-29c-3p into the nucleus accumbens (NAc) of mice, we observed the attenuation of METH-induced locomotor effects. Subsequent iTRAQ analysis identified 70 differentially expressed proteins (DEPs), with 22 up-regulated potential target proteins identified through miR-29c-3p target gene prediction and IPA analysis. Our focus extended to the number of neuronal branches, the excitatory synapse count, and locomotion-related pathways. Notably, GPR37, NPC1, and IREB2 emerged as potential target molecules for miR-29c-3p regulation, suggesting their involvement in the modulation of METH sensitization. Quantitative PCR confirmed the METH-induced aberrant expression of Gpr37, Npc1, and Ireb2 in the NAc of mice. Specifically, the over-expression of miR-29c-3p led to a significant reduction in the mRNA level of Gpr37, while the inhibition of miR-29c-3p resulted in a significant increase in the mRNA level of Gpr37, consistent with the regulatory principle of miRNAs modulating target gene expression. This suggests that miR-29c-3p potentially influences METH sensitization through its regulation of neuroplasticity. Our research indicates that miR-29c-3p plays a crucial role in regulating METH-induced sensitization, and it identified the potential molecular of miR-29c-3p in regulating METH-induced sensitization.
Collapse
Affiliation(s)
- Hang Su
- College of Forensic Medicine, Xi’an Jiaotong University Health Science Center, Xi’an 710061, China; (H.S.); (L.Z.); (L.S.); (M.L.); (R.W.); (J.Z.)
- The Key Laboratory of Health Ministry for Forensic Science, Xi’an Jiaotong University, Xi’an 710061, China
- National Biosafety Evidence Foundation, Bio-Evidence Sciences Academy, Western China Science and Technology Innovation Harbor, Xi’an Jiaotong University, Xi’an 710115, China
| | - Li Zhu
- College of Forensic Medicine, Xi’an Jiaotong University Health Science Center, Xi’an 710061, China; (H.S.); (L.Z.); (L.S.); (M.L.); (R.W.); (J.Z.)
- The Key Laboratory of Health Ministry for Forensic Science, Xi’an Jiaotong University, Xi’an 710061, China
- National Biosafety Evidence Foundation, Bio-Evidence Sciences Academy, Western China Science and Technology Innovation Harbor, Xi’an Jiaotong University, Xi’an 710115, China
| | - Linlan Su
- College of Forensic Medicine, Xi’an Jiaotong University Health Science Center, Xi’an 710061, China; (H.S.); (L.Z.); (L.S.); (M.L.); (R.W.); (J.Z.)
- The Key Laboratory of Health Ministry for Forensic Science, Xi’an Jiaotong University, Xi’an 710061, China
- National Biosafety Evidence Foundation, Bio-Evidence Sciences Academy, Western China Science and Technology Innovation Harbor, Xi’an Jiaotong University, Xi’an 710115, China
| | - Min Li
- College of Forensic Medicine, Xi’an Jiaotong University Health Science Center, Xi’an 710061, China; (H.S.); (L.Z.); (L.S.); (M.L.); (R.W.); (J.Z.)
- The Key Laboratory of Health Ministry for Forensic Science, Xi’an Jiaotong University, Xi’an 710061, China
- National Biosafety Evidence Foundation, Bio-Evidence Sciences Academy, Western China Science and Technology Innovation Harbor, Xi’an Jiaotong University, Xi’an 710115, China
| | - Rui Wang
- College of Forensic Medicine, Xi’an Jiaotong University Health Science Center, Xi’an 710061, China; (H.S.); (L.Z.); (L.S.); (M.L.); (R.W.); (J.Z.)
- The Key Laboratory of Health Ministry for Forensic Science, Xi’an Jiaotong University, Xi’an 710061, China
- National Biosafety Evidence Foundation, Bio-Evidence Sciences Academy, Western China Science and Technology Innovation Harbor, Xi’an Jiaotong University, Xi’an 710115, China
| | - Jie Zhu
- College of Forensic Medicine, Xi’an Jiaotong University Health Science Center, Xi’an 710061, China; (H.S.); (L.Z.); (L.S.); (M.L.); (R.W.); (J.Z.)
- The Key Laboratory of Health Ministry for Forensic Science, Xi’an Jiaotong University, Xi’an 710061, China
- National Biosafety Evidence Foundation, Bio-Evidence Sciences Academy, Western China Science and Technology Innovation Harbor, Xi’an Jiaotong University, Xi’an 710115, China
| | - Yanjiong Chen
- Department of Immunology and Pathogenic Biology, College of Basic Medicine, Xi’an Jiaotong University Health Science Center, Xi’an 710061, China;
| | - Teng Chen
- College of Forensic Medicine, Xi’an Jiaotong University Health Science Center, Xi’an 710061, China; (H.S.); (L.Z.); (L.S.); (M.L.); (R.W.); (J.Z.)
- The Key Laboratory of Health Ministry for Forensic Science, Xi’an Jiaotong University, Xi’an 710061, China
- National Biosafety Evidence Foundation, Bio-Evidence Sciences Academy, Western China Science and Technology Innovation Harbor, Xi’an Jiaotong University, Xi’an 710115, China
| |
Collapse
|
3
|
Eberwein AE, Kulkarni SS, Rushton E, Broadie K. Glycosphingolipids are linked to elevated neurotransmission and neurodegeneration in a Drosophila model of Niemann Pick type C. Dis Model Mech 2023; 16:dmm050206. [PMID: 37815467 PMCID: PMC10581387 DOI: 10.1242/dmm.050206] [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: 03/24/2023] [Accepted: 09/27/2023] [Indexed: 10/11/2023] Open
Abstract
The lipid storage disease Niemann Pick type C (NPC) causes neurodegeneration owing primarily to loss of NPC1. Here, we employed a Drosophila model to test links between glycosphingolipids, neurotransmission and neurodegeneration. We found that Npc1a nulls had elevated neurotransmission at the glutamatergic neuromuscular junction (NMJ), which was phenocopied in brainiac (brn) mutants, impairing mannosyl glucosylceramide (MacCer) glycosylation. Npc1a; brn double mutants had the same elevated synaptic transmission, suggesting that Npc1a and brn function within the same pathway. Glucosylceramide (GlcCer) synthase inhibition with miglustat prevented elevated neurotransmission in Npc1a and brn mutants, further suggesting epistasis. Synaptic MacCer did not accumulate in the NPC model, but GlcCer levels were increased, suggesting that GlcCer is responsible for the elevated synaptic transmission. Null Npc1a mutants had heightened neurodegeneration, but no significant motor neuron or glial cell death, indicating that dying cells are interneurons and that elevated neurotransmission precedes neurodegeneration. Glycosphingolipid synthesis mutants also had greatly heightened neurodegeneration, with similar neurodegeneration in Npc1a; brn double mutants, again suggesting that Npc1a and brn function in the same pathway. These findings indicate causal links between glycosphingolipid-dependent neurotransmission and neurodegeneration in this NPC disease model.
Collapse
Affiliation(s)
- Anna E. Eberwein
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
| | - Swarat S. Kulkarni
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
| | - Emma Rushton
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
| | - Kendal Broadie
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
- Department of Cell and Developmental Biology, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
- Vanderbilt Brain Institute, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
- Kennedy Center for Research on Human Development, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
| |
Collapse
|
4
|
Pfrieger FW. The Niemann-Pick type diseases – A synopsis of inborn errors in sphingolipid and cholesterol metabolism. Prog Lipid Res 2023; 90:101225. [PMID: 37003582 DOI: 10.1016/j.plipres.2023.101225] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 03/27/2023] [Accepted: 03/27/2023] [Indexed: 04/03/2023]
Abstract
Disturbances of lipid homeostasis in cells provoke human diseases. The elucidation of the underlying mechanisms and the development of efficient therapies represent formidable challenges for biomedical research. Exemplary cases are two rare, autosomal recessive, and ultimately fatal lysosomal diseases historically named "Niemann-Pick" honoring the physicians, whose pioneering observations led to their discovery. Acid sphingomyelinase deficiency (ASMD) and Niemann-Pick type C disease (NPCD) are caused by specific variants of the sphingomyelin phosphodiesterase 1 (SMPD1) and NPC intracellular cholesterol transporter 1 (NPC1) or NPC intracellular cholesterol transporter 2 (NPC2) genes that perturb homeostasis of two key membrane components, sphingomyelin and cholesterol, respectively. Patients with severe forms of these diseases present visceral and neurologic symptoms and succumb to premature death. This synopsis traces the tortuous discovery of the Niemann-Pick diseases, highlights important advances with respect to genetic culprits and cellular mechanisms, and exposes efforts to improve diagnosis and to explore new therapeutic approaches.
Collapse
|
5
|
Gascón-Bayarri J, Simon PC, Llop R, Carnaval T, Ledesma MD, Rico I, Sánchez-Castañeda C, Campdelacreu-Fumadó J, Calvo-Malvar N, Cos M, de Lama E, Cortés-Romera M, Rodríguez-Bel L, Pérez-Sousa C, Cerdán Sánchez M, Muelas N, Sevillano MD, Mir P, López de Munain A, Ferrer A, Videla S. Efficacy and safety clinical trial with efavirenz in patients diagnosed with adult Niemann-pick type C with cognitive impairment. Medicine (Baltimore) 2022; 101:e31471. [PMID: 36482560 PMCID: PMC9726274 DOI: 10.1097/md.0000000000031471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Niemann-Pick disease Type C (NPC) is a genetic, incurable, neurodegenerative disorder. This orphan disease is most frequently caused by mutations in the NPC1 protein, resulting in intralysossomal cholesterol accumulation. NPC1 is found in neuronal cell bodies, axon terminals and synaptosomes, suggesting it plays a role in lysosomal degradation pathway and in synaptic transmission. Neuronal function is especially vulnerable to NPC1 deficiency and synaptic changes seem a key element in disease development. Currently, Miglustat (Zavesca®) is the only approved treatment for NPC. However, preclinical evidence showed that low-dose Efavirenz reverted synaptic defects through pharmacological activation of the enzyme CYP46. METHODS This is a single-center, phase II clinical trial to evaluate the efficacy and safety of Efavirenz in addition to standard of care in patients diagnosed with adult or late juvenile-onset NPC with cognitive impairment. All enrolled patients will be treated orally with 25 mg/d of Efavirenz for 52 weeks (1 year). Secondary objectives include evaluating clinical (neurological and neuropsychological questionnaires) and biological (imaging and biochemical biomarkers) parameters. DISCUSSION NPC is still an unmet medical need. Although different therapeutic approaches are under study, this is the first clinical trial (to the best of our knowledge) studying the effects of Efavirenz in adult- and late-juvenile-onset NPC. Despite the small sample size and the single-arm design, we expect the results to show Efavirenz's capacity of activating the CYP46 enzyme to compensate for NPC1 deficiency and correct synaptic changes, therefore compensating cognitive and psychiatric changes in these patients. This study may provide direct benefit to enrolled patients in terms of slowing down the disease progression.
Collapse
Affiliation(s)
- Jordi Gascón-Bayarri
- Neurology Department, Bellvitge University Hospital, L’Hospitalet DE Llobregat, Barcelona, Spain
- Adult Lysosomal Diseases Clinical Expertise Unit, Bellvitge University Hospital, L’Hospitalet DE Llobregat, Barcelona, Spain
- Bellvitge Biomedical Research Institute (IDIBELL), L’Hospitalet DE Llobregat, Barcelona, Spain
- Department of Morphological Sciences, School of Medicine, Autonomous University of Barcelona, Bellaterra, Spain
| | - Petru Cristian Simon
- Clinical Pharmacology Department, Bellvitge University Hospital, L’Hospitalet de Llobregat, Barcelona, Spain
| | - Roser Llop
- Clinical Pharmacology Department, Bellvitge University Hospital, L’Hospitalet de Llobregat, Barcelona, Spain
| | - Thiago Carnaval
- Pharmacology Unit, Department of Pathology and Experimental Therapeutics, School of Medicine and Health Sciences, IDIBELL, University of Barcelona, L’Hospitalet DE Llobregat, Barcelona, Spain
- * Correspondence: Thiago Carnaval, Pharmacology Unit, Department of Pathology and Experimental Therapeutics, School of Medicine and Health Sciences, IDIBELL, University of Barcelona, L’Hospitalet DE Llobregat, Barcelona, Spain
| | | | - Imma Rico
- Neurology Department, Bellvitge University Hospital, L’Hospitalet DE Llobregat, Barcelona, Spain
- Bellvitge Biomedical Research Institute (IDIBELL), L’Hospitalet DE Llobregat, Barcelona, Spain
| | - Cristina Sánchez-Castañeda
- Neurology Department, Bellvitge University Hospital, L’Hospitalet DE Llobregat, Barcelona, Spain
- Bellvitge Biomedical Research Institute (IDIBELL), L’Hospitalet DE Llobregat, Barcelona, Spain
- Department of Clinical Psychology and Psychobiology, Neurosciences Institute, University of Barcelona, Barcelona, Spain
| | - Jaume Campdelacreu-Fumadó
- Neurology Department, Bellvitge University Hospital, L’Hospitalet DE Llobregat, Barcelona, Spain
- Bellvitge Biomedical Research Institute (IDIBELL), L’Hospitalet DE Llobregat, Barcelona, Spain
| | - Nahum Calvo-Malvar
- Bellvitge Biomedical Research Institute (IDIBELL), L’Hospitalet DE Llobregat, Barcelona, Spain
- Neuroradiology Department, Bellvitge University Hospital, L’Hospitalet DE Llobregat, Spain
| | - Mònica Cos
- Bellvitge Biomedical Research Institute (IDIBELL), L’Hospitalet DE Llobregat, Barcelona, Spain
- Neuroradiology Department, Bellvitge University Hospital, L’Hospitalet DE Llobregat, Spain
| | - Eugenia de Lama
- Bellvitge Biomedical Research Institute (IDIBELL), L’Hospitalet DE Llobregat, Barcelona, Spain
- Neuroradiology Department, Bellvitge University Hospital, L’Hospitalet DE Llobregat, Spain
| | - Montserrat Cortés-Romera
- Bellvitge Biomedical Research Institute (IDIBELL), L’Hospitalet DE Llobregat, Barcelona, Spain
- Nuclear Medicine-PET/CT Department (IDI). Bellvitge University Hospital, L’Hospitalet DE Llobregat, Spain
| | - Laura Rodríguez-Bel
- Bellvitge Biomedical Research Institute (IDIBELL), L’Hospitalet DE Llobregat, Barcelona, Spain
- Nuclear Medicine-PET/CT Department (IDI). Bellvitge University Hospital, L’Hospitalet DE Llobregat, Spain
| | - Celia Pérez-Sousa
- Neurology Department, A Coruña University Hospital Complex, A Coruña, Spain
| | - María Cerdán Sánchez
- Neurology Department, Santa Lucía-Santa María Rosell University Hospital, Cartagena, Spain
| | - Nuria Muelas
- Neurology Department, La Fe University and Polytechnical Hospital, Valencia, Spain
| | | | - Pablo Mir
- Movement Disorders Unit, Neurology and Clinical Neurophysiology Department, Seville Biomedical Institute, Virgen del Rocío University Hospital/CSIC/University of Seville, Seville, Spain
- Neurodegenerative Diseases Network of Biomedical Research Centers (CIBERNED), Madrid, Spain
- Medicine Departament, School of Medicine, University of Seville, Seville, Spain
| | - Adolfo López de Munain
- Neurodegenerative Diseases Network of Biomedical Research Centers (CIBERNED), Madrid, Spain
- Neurology Department, Donostia-Osakidetza University Hospital, San Sebastian, Spain
- Neuroscience Department, Biodonostia Institute, San Sebastian, Spain
- Neuroscience Department, University of the Basque Country, San Sebastian, Spain
| | - Anna Ferrer
- Pharmacy Department, Bellvitge University Hospital, L’Hospitalet de Llobregat, Barcelona, Spain
| | - Sebastián Videla
- Clinical Pharmacology Department, Bellvitge University Hospital, L’Hospitalet de Llobregat, Barcelona, Spain
- Pharmacology Unit, Department of Pathology and Experimental Therapeutics, School of Medicine and Health Sciences, IDIBELL, University of Barcelona, L’Hospitalet DE Llobregat, Barcelona, Spain
- Clinical Research Support Unit (HUB-IDIBELL: Bellvitge University Hospital & Bellvitge Biomedical Research Institute), Clinical Pharmacology Department, Bellvitge University Hospital, L’Hospitalet de Llobregat, Barcelona, Spain
| |
Collapse
|
6
|
Feng X, Yang F, Rabenstein M, Wang Z, Frech MJ, Wree A, Bräuer AU, Witt M, Gläser A, Hermann A, Rolfs A, Luo J. Stimulation of mGluR1/5 Improves Defective Internalization of AMPA Receptors in NPC1 Mutant Mouse. Cereb Cortex 2021; 30:1465-1480. [PMID: 31599924 DOI: 10.1093/cercor/bhz179] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Niemann-Pick type C1 (NPC1) disease is characterized by neurodegeneration caused by cholesterol accumulation in the late endosome/lysosome. In this study, a defective basal and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-stimulated internalization of GluR2-containing AMPA receptors in NPC1-/- cortical neurons was detected. Our results show that the amount of cholesterol and group I metabotropic glutamate receptors (mGluR1/5) in lipid rafts of NPC1-/- cortical tissue and neurons are decreased and their downstream signals of p-ERK are defective, which are restored by a rebalance of cholesterol homeostasis through β-cyclodextrin (β-CD) treatment. Application of 3,5-dihydroxyphenylglycine (DHPG)-a mGluR1/5 agonist-and β-CD markedly increases the internalization of AMPA receptors and decreases over-influx of calcium in NPC1-/- neurons, respectively. Furthermore, the defective phosphorylated GluR2 and protein kinase C signals are ameliorated by the treatment with DHPG and β-CD, respectively, suggesting an involvement of them in internalization dysfunction. Taken together, our data imply that abnormal internalization of AMPA receptors is a critical mechanism for neuronal dysfunction and the correction of dysfunctional mGluR1/5 is a potential therapeutic strategy for NPC1 disease.
Collapse
Affiliation(s)
- Xiao Feng
- Translational Neurodegeneration Section "Albrecht Kossel", Department of Neurology, University Medical Center Rostock, Rostock 18147, Germany
| | - Fan Yang
- Translational Neurodegeneration Section "Albrecht Kossel", Department of Neurology, University Medical Center Rostock, Rostock 18147, Germany
| | - Michael Rabenstein
- Translational Neurodegeneration Section "Albrecht Kossel", Department of Neurology, University Medical Center Rostock, Rostock 18147, Germany
| | - Zhen Wang
- Max Delbrück Center for Molecular Medicine, Berlin 13125, Germany
| | - Moritz J Frech
- Translational Neurodegeneration Section "Albrecht Kossel", Department of Neurology, University Medical Center Rostock, Rostock 18147, Germany.,Center for Transdisciplinary Neurosciences Rostock (CTNR), University Medical Center Rostock, University of Rostock, Rostock 18147, Germany
| | - Andreas Wree
- Center for Transdisciplinary Neurosciences Rostock (CTNR), University Medical Center Rostock, University of Rostock, Rostock 18147, Germany.,Institute of Anatomy, University Medical Center Rostock, Rostock 18055, Germany
| | - Anja U Bräuer
- Institute of Anatomy, University Medical Center Rostock, Rostock 18055, Germany.,Research Group Anatomy, School of Medicine and Health Sciences, Carl von Ossietzky University, Oldenburg 26129, Germany.,Research Center for Neurosensory Science, Carl von Ossietzky University, Oldenburg 26129, Germany
| | - Martin Witt
- Institute of Anatomy, University Medical Center Rostock, Rostock 18055, Germany
| | - Anne Gläser
- Institute of Anatomy, University Medical Center Rostock, Rostock 18055, Germany
| | - Andreas Hermann
- Translational Neurodegeneration Section "Albrecht Kossel", Department of Neurology, University Medical Center Rostock, Rostock 18147, Germany.,Center for Transdisciplinary Neurosciences Rostock (CTNR), University Medical Center Rostock, University of Rostock, Rostock 18147, Germany.,German Center for Neurodegenerative Diseases (DZNE), Rostock/Greifswald, Rostock 18147, Germany
| | | | - Jiankai Luo
- Translational Neurodegeneration Section "Albrecht Kossel", Department of Neurology, University Medical Center Rostock, Rostock 18147, Germany.,Center for Transdisciplinary Neurosciences Rostock (CTNR), University Medical Center Rostock, University of Rostock, Rostock 18147, Germany
| |
Collapse
|
7
|
Addressing neurodegeneration in lysosomal storage disorders: Advances in Niemann Pick diseases. Neuropharmacology 2019; 171:107851. [PMID: 31734384 DOI: 10.1016/j.neuropharm.2019.107851] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 10/11/2019] [Accepted: 11/08/2019] [Indexed: 12/16/2022]
Abstract
Most lysosomal storage disorders (LSDs) cause progressive neurodegeneration leading to early death. While the genetic defects that cause these disorders impact all cells of the body, neurons are particularly affected. This vulnerability may be explained by neuronal cells' critical dependence on the lysosomal degradative capacity, as they cannot use division to eliminate their waste. However, mounting evidence supports the extension of storage beyond lysosomes to other cellular compartments (mitochondria, plasma membrane and synapses) as a key event in pathogenesis. Impaired energy supply, oxidative stress, calcium imbalance, synaptic failure and glial alterations may all contribute to neuronal death and thus could be suitable therapeutic targets for these disorders. Here we review the pathological mechanisms underlying neurodegeneration in Niemann Pick diseases and therapeutic strategies developed in animal models and patients suffering from these devastating disorders. This article is part of the special issue entitled 'The Quest for Disease-Modifying Therapies for Neurodegenerative Disorders'.
Collapse
|
8
|
Mitroi DN, Pereyra‐Gómez G, Soto‐Huelin B, Senovilla F, Kobayashi T, Esteban JA, Ledesma MD. NPC1 enables cholesterol mobilization during long-term potentiation that can be restored in Niemann-Pick disease type C by CYP46A1 activation. EMBO Rep 2019; 20:e48143. [PMID: 31535451 PMCID: PMC6832102 DOI: 10.15252/embr.201948143] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 08/08/2019] [Accepted: 08/23/2019] [Indexed: 01/21/2023] Open
Abstract
NPC is a neurodegenerative disorder characterized by cholesterol accumulation in endolysosomal compartments. It is caused by mutations in the gene encoding NPC1, an endolysosomal protein mediating intracellular cholesterol trafficking. Cognitive and psychiatric alterations are hallmarks in NPC patients pointing to synaptic defects. However, the role of NPC1 in synapses has not been explored. We show that NPC1 is present in the postsynaptic compartment and is locally translated during LTP. A mutation in a region of the NPC1 gene commonly altered in NPC patients reduces NPC1 levels at synapses due to enhanced NPC1 protein degradation. This leads to shorter postsynaptic densities, increased synaptic cholesterol and impaired LTP in NPC1nmf164 mice with cognitive deficits. NPC1 mediates cholesterol mobilization and enables surface delivery of CYP46A1 and GluA1 receptors necessary for LTP, which is defective in NPC1nmf164 mice. Pharmacological activation of CYP46A1 normalizes synaptic levels of cholesterol, LTP and cognitive abilities, and extends life span of NPC1nmf164 mice. Our results unveil NPC1 as a regulator of cholesterol dynamics in synapses contributing to synaptic plasticity, and provide a potential therapeutic strategy for NPC patients.
Collapse
Affiliation(s)
- Daniel N Mitroi
- Department of Molecular NeuropathologyCentro de Biología Molecular “Severo Ochoa” (CSIC‐UAM)MadridSpain
| | - Guadalupe Pereyra‐Gómez
- Department of Molecular NeuropathologyCentro de Biología Molecular “Severo Ochoa” (CSIC‐UAM)MadridSpain
| | - Beatriz Soto‐Huelin
- Department of Molecular NeuropathologyCentro de Biología Molecular “Severo Ochoa” (CSIC‐UAM)MadridSpain
| | - Fernando Senovilla
- Department of Molecular NeuropathologyCentro de Biología Molecular “Severo Ochoa” (CSIC‐UAM)MadridSpain
| | - Toshihide Kobayashi
- Laboratoire de Biophotonique et PharmacologieFaculté de PharmacieUniversité de StrasbourgIllkirchFrance
| | - Jose A Esteban
- Department of Molecular NeuropathologyCentro de Biología Molecular “Severo Ochoa” (CSIC‐UAM)MadridSpain
| | - María Dolores Ledesma
- Department of Molecular NeuropathologyCentro de Biología Molecular “Severo Ochoa” (CSIC‐UAM)MadridSpain
| |
Collapse
|
9
|
Gabandé-Rodríguez E, Pérez-Cañamás A, Soto-Huelin B, Mitroi DN, Sánchez-Redondo S, Martínez-Sáez E, Venero C, Peinado H, Ledesma MD. Lipid-induced lysosomal damage after demyelination corrupts microglia protective function in lysosomal storage disorders. EMBO J 2018; 38:embj.201899553. [PMID: 30530526 PMCID: PMC6331723 DOI: 10.15252/embj.201899553] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 10/12/2018] [Accepted: 10/25/2018] [Indexed: 12/20/2022] Open
Abstract
Neuropathic lysosomal storage disorders (LSDs) present with activated pro‐inflammatory microglia. However, anti‐inflammatory treatment failed to improve disease pathology. We characterise the mechanisms underlying microglia activation in Niemann–Pick disease type A (NPA). We establish that an NPA patient and the acid sphingomyelinase knockout (ASMko) mouse model show amoeboid microglia in neurodegeneration‐prone areas. In vivo microglia ablation worsens disease progression in ASMko mice. We demonstrate the coexistence of different microglia phenotypes in ASMko brains that produce cytokines or counteract neuronal death by clearing myelin debris. Overloading microglial lysosomes through myelin debris accumulation and sphingomyelin build‐up induces lysosomal damage and cathepsin B extracellular release by lysosomal exocytosis. Inhibition of cathepsin B prevents neuronal death and behavioural anomalies in ASMko mice. Similar microglia phenotypes occur in a Niemann–Pick disease type C mouse model and patient. Our results show a protective function for microglia in LSDs and how this is corrupted by lipid lysosomal overload. Data indicate cathepsin B as a key molecule mediating neurodegeneration, opening research pathways for therapeutic targeting of LSDs and other demyelinating diseases.
Collapse
Affiliation(s)
- Enrique Gabandé-Rodríguez
- Department of Molecular Neuropathology, Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM), Madrid, Spain .,Barts Cancer Institute, Centre for Cancer & Inflammation, Queen Mary University of London, London, UK
| | - Azucena Pérez-Cañamás
- Department of Molecular Neuropathology, Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM), Madrid, Spain
| | - Beatriz Soto-Huelin
- Department of Molecular Neuropathology, Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM), Madrid, Spain
| | - Daniel N Mitroi
- Department of Molecular Neuropathology, Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM), Madrid, Spain
| | - Sara Sánchez-Redondo
- Microenvironment and Metastasis Group, Molecular Oncology Program, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Elena Martínez-Sáez
- Department of Pathology, Hospital Universitario Vall d'Hebron, Barcelona, Spain
| | - César Venero
- Department of Psychobiology, Universidad Nacional de Educación a Distancia, Madrid, Spain
| | - Héctor Peinado
- Microenvironment and Metastasis Group, Molecular Oncology Program, Spanish National Cancer Research Centre (CNIO), Madrid, Spain.,Department of Pediatrics, Drukier Institute for Children's Health and Meyer Cancer Center, Weill Cornell Medical College, New York, NY, USA
| | - María Dolores Ledesma
- Department of Molecular Neuropathology, Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM), Madrid, Spain
| |
Collapse
|
10
|
Feng X, Bader BM, Yang F, Segura M, Schultz L, Schröder OHU, Rolfs A, Luo J. Improvement of impaired electrical activity in NPC1 mutant cortical neurons upon DHPG stimulation detected by micro-electrode array. Brain Res 2018; 1694:87-93. [PMID: 29753706 DOI: 10.1016/j.brainres.2018.05.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 04/20/2018] [Accepted: 05/09/2018] [Indexed: 12/20/2022]
Abstract
Niemann-Pick Type C1 (NPC1) disease is an autosomal recessive neurodegenerative disease characterized by an excessive accumulation of unesterified cholesterol in late endosomes/lysosomes. Patients with NPC1 disease show a series of symptoms in neuropathology, including a gradually increased loss of motor control and seizures. However, mechanism of the neurological manifestations in NPC1 disease is not fully understood yet. In this study, we utilized the micro-electrode array (MEA) to analyze the spontaneous extracellular electrical activity in cultivated cortical neurons of the NPC1 mutant (NPC1-/-) mouse. Our results show a decrease of the spontaneous electrical activity in NPC1-/- neuronal network when compared to wild type neurons, as indicated by the decreased spike rate, burst rate, event rate, and the increased burst period and event period. Application of 3,5-dihydroxyphenylglycine (DHPG), a specific agonist of group I metabotropic glutamate receptors, improved the electrical activity of the NPC1-/- neuronal network, suggesting that DHPG can be used as a potential therapeutic strategy for recovery of the electrical activity in NPC1 disease.
Collapse
Affiliation(s)
- Xiao Feng
- Albrecht-Kossel-Institute for Neuroregeneration, Rostock University Medical Center, Gehlsheimer Straße 20, 18147 Rostock, Germany
| | - Benjamin M Bader
- NeuroProof GmbH, Friedrich-Barnewitz-Straße 4, 18119 Rostock, Germany
| | - Fan Yang
- Albrecht-Kossel-Institute for Neuroregeneration, Rostock University Medical Center, Gehlsheimer Straße 20, 18147 Rostock, Germany
| | - Monica Segura
- NeuroProof GmbH, Friedrich-Barnewitz-Straße 4, 18119 Rostock, Germany
| | - Luise Schultz
- NeuroProof GmbH, Friedrich-Barnewitz-Straße 4, 18119 Rostock, Germany
| | - Olaf H-U Schröder
- NeuroProof GmbH, Friedrich-Barnewitz-Straße 4, 18119 Rostock, Germany
| | - Arndt Rolfs
- Albrecht-Kossel-Institute for Neuroregeneration, Rostock University Medical Center, Gehlsheimer Straße 20, 18147 Rostock, Germany
| | - Jiankai Luo
- Albrecht-Kossel-Institute for Neuroregeneration, Rostock University Medical Center, Gehlsheimer Straße 20, 18147 Rostock, Germany; Centre for Transdisciplinary Neuroscience Rostock, Rostock University Medical Center, Gehlsheimer Straße 20, 18147 Rostock, Germany.
| |
Collapse
|
11
|
Luarte A, Cornejo VH, Bertin F, Gallardo J, Couve A. The axonal endoplasmic reticulum: One organelle-many functions in development, maintenance, and plasticity. Dev Neurobiol 2017; 78:181-208. [PMID: 29134778 DOI: 10.1002/dneu.22560] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 11/02/2017] [Accepted: 11/07/2017] [Indexed: 12/11/2022]
Abstract
The endoplasmic reticulum (ER) is highly conserved in eukaryotes and neurons. Indeed, the localization of the organelle in axons has been known for nearly half a century. However, the relevance of the axonal ER is only beginning to emerge. In this review, we discuss the structure of the ER in axons, examining the role of ER-shaping proteins and highlighting reticulons. We analyze the multiple functions of the ER and their potential contribution to axonal physiology. First, we examine the emerging roles of the axonal ER in lipid synthesis, protein translation, processing, quality control, and secretory trafficking of transmembrane proteins. We also review the impact of the ER on calcium dynamics, focusing on intracellular mechanisms and functions. We describe the interactions between the ER and endosomes, mitochondria, and synaptic vesicles. Finally, we analyze available proteomic data of axonal preparations to reveal the dynamic functionality of the ER in axons during development. We suggest that the dynamic proteome and a validated axonal interactome, together with state-of-the-art methodologies, may provide interesting research avenues in axon physiology that may extend to pathology and regeneration. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 78: 181-208, 2018.
Collapse
Affiliation(s)
- Alejandro Luarte
- Department of Neuroscience, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Víctor Hugo Cornejo
- Department of Neuroscience, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Francisca Bertin
- Department of Neuroscience, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Javiera Gallardo
- Department of Neuroscience, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Andrés Couve
- Department of Neuroscience, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| |
Collapse
|
12
|
Reversal of Pathologic Lipid Accumulation in NPC1-Deficient Neurons by Drug-Promoted Release of LAMP1-Coated Lamellar Inclusions. J Neurosci 2017; 36:8012-25. [PMID: 27466344 DOI: 10.1523/jneurosci.0900-16.2016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 06/15/2016] [Indexed: 02/05/2023] Open
Abstract
UNLABELLED Aging and pathologic conditions cause intracellular aggregation of macromolecules and the dysfunction and degeneration of neurons, but the mechanisms are largely unknown. Prime examples are lysosomal storage disorders such as Niemann-Pick type C (NPC) disease, where defects in the endosomal-lysosomal protein NPC1 or NPC2 cause intracellular accumulation of unesterified cholesterol and other lipids leading to neurodegeneration and fatal neurovisceral symptoms. Here, we investigated the impact of NPC1 deficiency on rodent neurons using pharmacologic and genetic models of the disease. Improved ultrastructural detection of lipids and correlative light and electron microscopy identified lamellar inclusions as the subcellular site of cholesterol accumulation in neurons with impaired NPC1 activity. Immunogold labeling combined with transmission electron microscopy revealed the presence of CD63 on internal lamellae and of LAMP1 on the membrane surrounding the inclusions, indicating their origins from intraluminal vesicles of late endosomes and of a lysosomal compartment, respectively. Lamellar inclusions contained cell-intrinsic cholesterol and surface-labeled GM1, indicating the incorporation of plasma membrane components. Scanning electron microscopy revealed that the therapeutic drug candidate β-cyclodextrin induces the subplasmalemmal location of lamellar inclusions and their subsequent release to the extracellular space. In parallel, β-cyclodextrin mediated the NPC1-independent redistribution of cholesterol within neurons and thereby abolished a deleterious cycle of enhanced cholesterol synthesis and its intracellular accumulation, which was indicated by neuron-specific transcript analysis. Our study provides new mechanistic insight into the pathologic aggregation of macromolecules in neurons and suggests exocytosis as cellular target for its therapeutic reversal. SIGNIFICANCE STATEMENT Many neurodegenerative diseases involve pathologic accumulation of molecules within neurons, but the subcellular location and the cellular impact are often unknown and therapeutic approaches lacking. We investigated these questions in the lysosomal storage disorder Niemann-Pick type C (NPC), where a defect in intracellular cholesterol transport causes loss of neurons and fatal neurovisceral symptoms. Here, we identify lamellar inclusions as the subcellular site of lipid accumulation in neurons, we uncover a vicious cycle of cholesterol synthesis and accretion, which may cause gradual neurodegeneration, and we reveal how β-cyclodextrin, a potential therapeutic drug, reverts these changes. Our study provides new mechanistic insight in NPC disease and uncovers new targets for therapeutic approaches.
Collapse
|
13
|
Caporali P, Bruno F, Palladino G, Dragotto J, Petrosini L, Mangia F, Erickson RP, Canterini S, Fiorenza MT. Developmental delay in motor skill acquisition in Niemann-Pick C1 mice reveals abnormal cerebellar morphogenesis. Acta Neuropathol Commun 2016; 4:94. [PMID: 27586038 PMCID: PMC5009663 DOI: 10.1186/s40478-016-0370-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 08/18/2016] [Indexed: 12/11/2022] Open
Abstract
Niemann-Pick type C1 (NPC1) disease is a lysosomal storage disorder caused by defective intracellular trafficking of exogenous cholesterol. Purkinje cell (PC) degeneration is the main sign of cerebellar dysfunction in both NPC1 patients and animal models. It has been recently shown that a significant decrease in Sonic hedgehog (Shh) expression reduces the proliferative potential of granule neuron precursors in the developing cerebellum of Npc1−/− mice. Pursuing the hypothesis that this developmental defect translates into functional impairments, we have assayed Npc1-deficient pups belonging to the milder mutant mouse strain Npc1nmf164 for sensorimotor development from postnatal day (PN) 3 to PN21. Npc1nmf164/ Npc1nmf164 pups displayed a 2.5-day delay in the acquisition of complex motor abilities compared to wild-type (wt) littermates, in agreement with the significant disorganization of cerebellar cortex cytoarchitecture observed between PN11 and PN15. Compared to wt, Npc1nmf164 homozygous mice exhibited a poorer morphological differentiation of Bergmann glia (BG), as indicated by thicker radial shafts and less elaborate reticular pattern of lateral processes. Also BG functional development was defective, as indicated by the significant reduction in GLAST and Glutamine synthetase expression. A reduced VGluT2 and GAD65 expression also indicated an overall derangement of the glutamatergic/GABAergic stimulation that PCs receive by climbing/parallel fibers and basket/stellate cells, respectively. Lastly, Npc1-deficiency also affected oligodendrocyte differentiation as indicated by the strong reduction of myelin basic protein. Two sequential 2-hydroxypropyl-β-cyclodextrin administrations at PN4 and PN7 counteract these defects, partially preventing functional impairment of BG and fully restoring the normal patterns of glutamatergic/GABAergic stimulation to PCs. These findings indicate that in Npc1nmf164 homozygous mice the derangement of synaptic connectivity and dysmyelination during cerebellar morphogenesis largely anticipate motor deficits that are typically observed during adulthood.
Collapse
|
14
|
Martín MG, Pfrieger F, Dotti CG. Cholesterol in brain disease: sometimes determinant and frequently implicated. EMBO Rep 2014; 15:1036-52. [PMID: 25223281 DOI: 10.15252/embr.201439225] [Citation(s) in RCA: 209] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Cholesterol is essential for neuronal physiology, both during development and in the adult life: as a major component of cell membranes and precursor of steroid hormones, it contributes to the regulation of ion permeability, cell shape, cell-cell interaction, and transmembrane signaling. Consistently, hereditary diseases with mutations in cholesterol-related genes result in impaired brain function during early life. In addition, defects in brain cholesterol metabolism may contribute to neurological syndromes, such as Alzheimer's disease (AD), Huntington's disease (HD), and Parkinson's disease (PD), and even to the cognitive deficits typical of the old age. In these cases, brain cholesterol defects may be secondary to disease-causing elements and contribute to the functional deficits by altering synaptic functions. In the first part of this review, we will describe hereditary and non-hereditary causes of cholesterol dyshomeostasis and the relationship to brain diseases. In the second part, we will focus on the mechanisms by which perturbation of cholesterol metabolism can affect synaptic function.
Collapse
Affiliation(s)
- Mauricio G Martín
- Instituto de Investigaciones Médicas Mercedes y Martín Ferreyra (INIMEC-CONICET-UNC), Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Frank Pfrieger
- Institute of Cellular and Integrative Neurosciences, CNRS UPR 3212, University of Strasbourg, Strasbourg, France
| | - Carlos G Dotti
- Centro Biología Molecular 'Severo Ochoa' CSIC-UAM, Madrid, Spain
| |
Collapse
|
15
|
Buard I, Pfrieger FW. Relevance of neuronal and glial NPC1 for synaptic input to cerebellar Purkinje cells. Mol Cell Neurosci 2014; 61:65-71. [DOI: 10.1016/j.mcn.2014.06.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 05/27/2014] [Accepted: 06/05/2014] [Indexed: 10/25/2022] Open
|
16
|
Vance JE, Karten B. Niemann-Pick C disease and mobilization of lysosomal cholesterol by cyclodextrin. J Lipid Res 2014; 55:1609-21. [PMID: 24664998 DOI: 10.1194/jlr.r047837] [Citation(s) in RCA: 119] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Indexed: 12/31/2022] Open
Abstract
Niemann-Pick type C (NPC) disease is a lysosomal storage disease in which endocytosed cholesterol becomes sequestered in late endosomes/lysosomes (LEs/Ls) because of mutations in either the NPC1 or NPC2 gene. Mutations in either of these genes can lead to impaired functions of the NPC1 or NPC2 proteins and progressive neurodegeneration as well as liver and lung disease. NPC1 is a polytopic protein of the LE/L limiting membrane, whereas NPC2 is a soluble protein in the LE/L lumen. These two proteins act in tandem and promote the export of cholesterol from LEs/Ls. Consequently, a defect in either NPC1 or NPC2 causes cholesterol accumulation in LEs/Ls. In this review, we summarize the molecular mechanisms leading to NPC disease, particularly in the CNS. Recent exciting data on the mechanism by which the cholesterol-sequestering agent cyclodextrin can bypass the functions of NPC1 and NPC2 in the LEs/Ls, and mobilize cholesterol from LEs/Ls, will be highlighted. Moreover, the possible use of cyclodextrin as a valuable therapeutic agent for treatment of NPC patients will be considered.
Collapse
Affiliation(s)
- Jean E Vance
- The Group on Molecular and Cell Biology of Lipids and Department of Medicine, University of Alberta, Edmonton, AB, Canada
| | - Barbara Karten
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada
| |
Collapse
|
17
|
Cholesterol and phospholipids in frontal cortex and synaptosomes of suicide completers: relationship with endosomal lipid trafficking genes. J Psychiatr Res 2013; 47:272-9. [PMID: 23164340 DOI: 10.1016/j.jpsychires.2012.10.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Revised: 10/17/2012] [Accepted: 10/30/2012] [Indexed: 11/21/2022]
Abstract
Cholesterol (CHL) and phospholipid (PL) levels in synaptosomal membranes in particular can have an impact on cell signalling. Alterations in peripheral CHL measures have been consistently reported in suicidal behaviour. As CHL and PL turnover in the brain are important in synapse maintenance and function, the objective of this study was to determine if differences exist in synaptosomal cholesterol and phospholipid levels between suicide completers and controls. Expression measures of genes involved in lipid trafficking suggest an association between Lysosomal acid lipase A, cholesteryl ester hydrolase (LIPA) and brain PL levels, with LIPA being significantly increased in violent suicides and associated with alterations in brain PL. The results of this study suggest an altered PL content mediated by LIPA expression in violent suicides in the prefrontal cortex, which would have important consequences for inhibitory neurotransmission.
Collapse
|
18
|
Vance JE. Dysregulation of cholesterol balance in the brain: contribution to neurodegenerative diseases. Dis Model Mech 2012; 5:746-55. [PMID: 23065638 PMCID: PMC3484857 DOI: 10.1242/dmm.010124] [Citation(s) in RCA: 219] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Dysregulation of cholesterol homeostasis in the brain is increasingly being linked to chronic neurodegenerative disorders, including Alzheimer’s disease (AD), Huntington’s disease (HD), Parkinson’s disease (PD), Niemann-Pick type C (NPC) disease and Smith-Lemli Opitz syndrome (SLOS). However, the molecular mechanisms underlying the correlation between altered cholesterol metabolism and the neurological deficits are, for the most part, not clear. NPC disease and SLOS are caused by mutations in genes involved in the biosynthesis or intracellular trafficking of cholesterol, respectively. However, the types of neurological impairments, and the areas of the brain that are most affected, differ between these diseases. Some, but not all, studies indicate that high levels of plasma cholesterol correlate with increased risk of developing AD. Moreover, inheritance of the E4 isoform of apolipoprotein E (APOE), a cholesterol-carrying protein, markedly increases the risk of developing AD. Whether or not treatment of AD with statins is beneficial remains controversial, and any benefit of statin treatment might be due to anti-inflammatory properties of the drug. Cholesterol balance is also altered in HD and PD, although no causal link between dysregulated cholesterol homeostasis and neurodegeneration has been established. Some important considerations for treatment of neurodegenerative diseases are the impermeability of the blood-brain barrier to many therapeutic agents and difficulties in reversing brain damage that has already occurred. This article focuses on how cholesterol balance in the brain is altered in several neurodegenerative diseases, and discusses some commonalities and differences among the diseases.
Collapse
Affiliation(s)
- Jean E Vance
- Group on the Molecular and Cell Biology of Lipids and Department of Medicine, University of Alberta, Edmonton, AB, T6G 2S2, Canada.
| |
Collapse
|
19
|
Exocytosis is impaired in mucopolysaccharidosis IIIA mouse chromaffin cells. Neuroscience 2012; 227:110-8. [PMID: 23022219 DOI: 10.1016/j.neuroscience.2012.09.034] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Revised: 08/28/2012] [Accepted: 09/13/2012] [Indexed: 11/22/2022]
Abstract
Mucopolysaccharidosis IIIA (MPS IIIA) is a lysosomal storage disorder caused by a deficiency in the activity of the lysosomal hydrolase, sulphamidase, an enzyme involved in the degradation of heparan sulphate. MPS IIIA patients exhibit progressive mental retardation and behavioural disturbance. While neuropathology is the major clinical problem in MPS IIIA patients, there is little understanding of how lysosomal storage generates this phenotype. As reduced neuronal communication can underlie cognitive deficiencies, we investigated whether the secretion of neurotransmitters is altered in MPS IIIA mice; utilising adrenal chromaffin cells, a classical model for studying secretion via exocytosis. MPS IIIA chromaffin cells displayed heparan sulphate storage and electron microscopy revealed large electron-lucent storage compartments. There were also increased numbers of large/elongated chromaffin granules, with a morphology that was similar to immature secretory granules. Carbon fibre amperometry illustrated a significant decrease in the number of exocytotic events for MPS IIIA, when compared to control chromaffin cells. However, there were no changes in the kinetics of release, the amount of catecholamine released per exocytotic event, or the amount of Ca(2+) entry upon stimulation. The increased number of large/elongated granules and reduced number of exocytotic events suggests that either the biogenesis and/or the cell surface docking and fusion potential of these vesicles is impaired in MPS IIIA. If this also occurs in central nervous system neurons, the reduction in neurotransmitter release could help to explain the development of neuropathology in MPS IIIA.
Collapse
|
20
|
Ong QR, Lim ML, Chua CC, Cheung NS, Wong BS. Impaired insulin signaling in an animal model of Niemann-Pick Type C disease. Biochem Biophys Res Commun 2012; 424:482-7. [PMID: 22776200 DOI: 10.1016/j.bbrc.2012.06.139] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2012] [Accepted: 06/26/2012] [Indexed: 01/22/2023]
Abstract
Studies have shown similarities between the histopathological characteristics of NPC and Alzheimer's disease (AD) including amyloid and tau pathologies. While dysfunction in insulin signaling was widely detected in AD brain, the function of insulin signaling proteins has not been examined in NPC disease. In this study, we have examined the expression and phosphorylation of proteins linked to the insulin signaling pathway in the brain of 9 weeks old NPC(nih) mice. Our results showed lower expression of insulin receptor substrate 2 (IRS2) in the NPC(nih) mice, and insulin receptor substrate 1 (IRS1) expression was almost non-detectable in this NPC mouse model. This reduction was associated with the loss of expression for the regulatory p85 subunit of phosphatidylinositol 3-kinase (p85/PI3K). Interestingly, the impairment was observed to link to a greater reduction of Akt phosphorylation at residue T308 than S473. This aberrant Akt phosphorylation could be contributing to lower GSK3β phosphorylation detected in the NPC(nih) mouse brain. To our knowledge, this is the first report documenting impaired insulin signaling in the brain of a NPC mouse model.
Collapse
Affiliation(s)
- Qi-Rui Ong
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | | | | | | | | |
Collapse
|
21
|
Pressey SNR, Smith DA, Wong AMS, Platt FM, Cooper JD. Early glial activation, synaptic changes and axonal pathology in the thalamocortical system of Niemann-Pick type C1 mice. Neurobiol Dis 2011; 45:1086-100. [PMID: 22198570 PMCID: PMC3657200 DOI: 10.1016/j.nbd.2011.12.027] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Revised: 11/21/2011] [Accepted: 12/08/2011] [Indexed: 11/17/2022] Open
Abstract
Niemann–Pick disease type C (NPC) is an inherited lysosomal storage disease characterised by accumulation of cholesterol and glycosphingolipids. NPC patients suffer a progressive neurodegenerative phenotype presenting with motor dysfunction, mental retardation and cognitive decline. To examine the onset and progression of neuropathological insults in NPC we have systematically examined the CNS of a mouse model of NPC1 (Npc1−/− mice) at different stages of the disease course. This revealed a specific spatial and temporal pattern of neuropathology in Npc1−/− mice, highlighting that sensory thalamic pathways are particularly vulnerable to loss of NPC1 resulting in neurodegeneration in Npc1−/− mice. Examination of markers of astrocytosis and microglial activation revealed a particularly pronounced reactive gliosis in the thalamus early in the disease, which subsequently also occurred in interconnected cortical laminae at later ages. Our examination of the precise staging of events demonstrate that the relationship between glia and neurons varies between brain regions in Npc1−/− mice, suggesting that the cues causing glial reactivity may differ between brain regions. In addition, aggregations of pre-synaptic markers are apparent in white matter tracts and the thalamus and are likely to be formed within axonal spheroids. Our data provide a new perspective, revealing a number of events that occur prior to and alongside neuron loss and highlighting that these occur in a pathway dependent manner.
Collapse
Affiliation(s)
- Sarah N R Pressey
- Department of Neuroscience and Centre for Cellular Basis of Behaviour, MRC Centre for Neurodegeneration Research, James Black Centre, Institute of Psychiatry, King's College London, 125 Coldharbour Lane, London, SE5 9NU, UK
| | | | | | | | | |
Collapse
|
22
|
Pfrieger FW, Ungerer N. Cholesterol metabolism in neurons and astrocytes. Prog Lipid Res 2011; 50:357-71. [PMID: 21741992 DOI: 10.1016/j.plipres.2011.06.002] [Citation(s) in RCA: 325] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2011] [Revised: 06/11/2011] [Accepted: 06/22/2011] [Indexed: 12/20/2022]
Abstract
Cells in the mammalian body must accurately maintain their content of cholesterol, which is an essential membrane component and precursor for vital signalling molecules. Outside the brain, cholesterol homeostasis is guaranteed by a lipoprotein shuttle between the liver, intestine and other organs via the blood circulation. Cells inside the brain are cut off from this circuit by the blood-brain barrier and must regulate their cholesterol content in a different manner. Here, we review how this is accomplished by neurons and astrocytes, two cell types of the central nervous system, whose cooperation is essential for normal brain development and function. The key observation is a remarkable cell-specific distribution of proteins that mediate different steps of cholesterol metabolism. This form of metabolic compartmentalization identifies astrocytes as net producers of cholesterol and neurons as consumers with unique means to prevent cholesterol overload. The idea that cholesterol turnover in neurons depends on close cooperation with astrocytes raises new questions that need to be addressed by new experimental approaches to monitor and manipulate cholesterol homeostasis in a cell-specific manner. We conclude that an understanding of cholesterol metabolism in the brain and its role in disease requires a close look at individual cell types.
Collapse
Affiliation(s)
- Frank W Pfrieger
- CNRS UPR 3212, University of Strasbourg, Institute of Cellular and Integrative Neurosciences (INCI), 67084 Strasbourg Cedex, France.
| | | |
Collapse
|
23
|
Comps-Agrar L, Kniazeff J, Nørskov-Lauritsen L, Maurel D, Gassmann M, Gregor N, Prézeau L, Bettler B, Durroux T, Trinquet E, Pin JP. The oligomeric state sets GABA(B) receptor signalling efficacy. EMBO J 2011; 30:2336-49. [PMID: 21552208 PMCID: PMC3116278 DOI: 10.1038/emboj.2011.143] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Accepted: 04/11/2011] [Indexed: 12/20/2022] Open
Abstract
G protein-coupled receptors (GPCRs) have key roles in cell-cell communication. Recent data suggest that these receptors can form large complexes, a possibility expected to expand the complexity of this regulatory system. Among the brain GPCRs, the heterodimeric GABA(B) receptor is one of the most abundant, being distributed in most brain regions, on either pre- or post-synaptic elements. Here, using specific antibodies labelled with time-resolved FRET compatible fluorophores, we provide evidence that the heterodimeric GABA(B) receptor can form higher-ordered oligomers in the brain, as suggested by the close proximity of the GABA(B1) subunits. Destabilizing the oligomers using a competitor or a GABA(B1) mutant revealed different G protein coupling efficiencies depending on the oligomeric state of the receptor. By examining, in heterologous system, the G protein coupling properties of such GABA(B) receptor oligomers composed of a wild-type and a non-functional mutant heterodimer, we provide evidence for a negative functional cooperativity between the GABA(B) heterodimers.
Collapse
Affiliation(s)
- Laëtitia Comps-Agrar
- CNRS, UMR5203, Institut de Génomique Fonctionnelle, Department of Molecular Pharmacology, Montpellier, France
- INSERM, U661, Montpellier, France
- Universités de Montpellier 1 and 2, UMR5203, Montpellier, France
- Cisbio, Parc Technologique Marcel Boiteux, Bagnols/Cèze Cedex, France
| | - Julie Kniazeff
- CNRS, UMR5203, Institut de Génomique Fonctionnelle, Department of Molecular Pharmacology, Montpellier, France
- INSERM, U661, Montpellier, France
- Universités de Montpellier 1 and 2, UMR5203, Montpellier, France
| | - Lenea Nørskov-Lauritsen
- CNRS, UMR5203, Institut de Génomique Fonctionnelle, Department of Molecular Pharmacology, Montpellier, France
- INSERM, U661, Montpellier, France
- Universités de Montpellier 1 and 2, UMR5203, Montpellier, France
| | - Damien Maurel
- CNRS, UMR5203, Institut de Génomique Fonctionnelle, Department of Molecular Pharmacology, Montpellier, France
- INSERM, U661, Montpellier, France
- Universités de Montpellier 1 and 2, UMR5203, Montpellier, France
- Cisbio, Parc Technologique Marcel Boiteux, Bagnols/Cèze Cedex, France
| | - Martin Gassmann
- Department of Biomedicine, Institute of Physiology, Pharmazentrum, University of Basel, Basel, Switzerland
| | - Nathalie Gregor
- Cisbio, Parc Technologique Marcel Boiteux, Bagnols/Cèze Cedex, France
| | - Laurent Prézeau
- CNRS, UMR5203, Institut de Génomique Fonctionnelle, Department of Molecular Pharmacology, Montpellier, France
- INSERM, U661, Montpellier, France
- Universités de Montpellier 1 and 2, UMR5203, Montpellier, France
| | - Bernhard Bettler
- Department of Biomedicine, Institute of Physiology, Pharmazentrum, University of Basel, Basel, Switzerland
| | - Thierry Durroux
- CNRS, UMR5203, Institut de Génomique Fonctionnelle, Department of Molecular Pharmacology, Montpellier, France
- INSERM, U661, Montpellier, France
- Universités de Montpellier 1 and 2, UMR5203, Montpellier, France
| | - Eric Trinquet
- Cisbio, Parc Technologique Marcel Boiteux, Bagnols/Cèze Cedex, France
| | - Jean-Philippe Pin
- CNRS, UMR5203, Institut de Génomique Fonctionnelle, Department of Molecular Pharmacology, Montpellier, France
- INSERM, U661, Montpellier, France
- Universités de Montpellier 1 and 2, UMR5203, Montpellier, France
| |
Collapse
|
24
|
Abstract
Synaptic vesicles have a high sterol content, but the importance of vesicular sterols during vesicle recycling is unclear. We used the Drosophila temperature-sensitive dynamin mutant, shibire-ts1, to block endocytosis of recycling synaptic vesicles and to trap them reversibly at the plasma membrane where they were accessible to sterol extraction. Depletion of sterols from trapped vesicles prevented recovery of synaptic transmission after removal of the endocytic block. Measurement of vesicle recycling with synaptopHluorin, FM1-43, and FM4-64 demonstrated impaired membrane retrieval after vesicular sterol depletion. When plasma membrane sterols were extracted before vesicle trapping, no vesicle recycling defects were observed. Ultrastructural analysis indicated accumulation of endosomes and a defect in the formation of synaptic vesicles in synaptic terminals subjected to vesicular sterol depletion. Our results demonstrate the importance of a high vesicular sterol concentration for endocytosis and suggest that vesicular and membrane sterol pools do not readily intermingle during vesicle recycling.
Collapse
|
25
|
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.
Collapse
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
| | | | | | | | | | | | | | | |
Collapse
|
26
|
Hawes CM, Wiemer H, Krueger SR, Karten B. Pre-synaptic defects of NPC1-deficient hippocampal neurons are not directly related to plasma membrane cholesterol. J Neurochem 2010; 114:311-22. [PMID: 20456004 DOI: 10.1111/j.1471-4159.2010.06768.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Imbalances in brain cholesterol homeostasis have been observed in several neurodegenerative diseases. In Niemann-Pick Type C (NPC) disease, mutations in NPC1 or NPC2 lead to endosomal cholesterol accumulation, neuronal dysfunction and death. Cholesterol in synaptic plasma membranes influences membrane fluidity, curvature, and protein function, and its depletion may adversely affect synaptic vesicle cycling. We have investigated pre-synaptic function in primary hippocampal neurons with altered cholesterol distribution because of NPC1 deficiency or cyclodextrin treatment. In NPC1-deficient neurons grown in serum-free medium, plasma membrane cholesterol was reduced and total synaptic vesicle release during prolonged stimulation was attenuated. In NPC1-deficient neurons cultured in the presence of high-density lipoproteins, plasma membrane cholesterol markedly increased, but the defects in synaptic vesicle release in NPC1-deficient neurons were exacerbated. Treatment with 1 mM methyl-beta-cyclodextrin acutely depleted plasma membrane cholesterol in wild-type neurons to levels below those in NPC1 deficiency, but did not alter synaptic vesicle exo- or endocytosis. Defects only became apparent when higher methyl-beta-cyclodextrin concentrations were used. Our data indicate that synaptic vesicle release can tolerate some degree of plasma membrane cholesterol depletion and suggest that the pre-synaptic defects in NPC1-deficient neurons are not solely caused by a reduction of plasma membrane cholesterol.
Collapse
Affiliation(s)
- Cory M Hawes
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 1X5, Canada
| | | | | | | |
Collapse
|
27
|
Peake KB, Vance JE. Defective cholesterol trafficking in Niemann-Pick C-deficient cells. FEBS Lett 2010; 584:2731-9. [PMID: 20416299 DOI: 10.1016/j.febslet.2010.04.047] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2010] [Revised: 04/15/2010] [Accepted: 04/16/2010] [Indexed: 11/29/2022]
Abstract
Pathways of intracellular cholesterol trafficking are poorly understood at the molecular level. Mutations in Niemann-Pick C (NPC) proteins, NPC1 and NPC2, however, have led to insights into the mechanism by which endocytosed cholesterol is exported from late endosomes/lysosomes (LE/L). Mutations in NPC1, a multi-spanning membrane protein of LE/L, or mutations in NPC2, a soluble luminal protein of LE/L, cause the neurodegenerative disorder NPC disease. This review focuses on data supporting a model in which movement of cholesterol out of LE/L is mediated by the sequential action of the two NPC proteins. We also discuss potential therapies for NPC disease, including evidence that treatment of NPC-deficient mice with the cholesterol-binding compound, cyclodextrin, markedly attenuates neurodegeneration, and increases life-span, of NPC1-deficient mice.
Collapse
Affiliation(s)
- Kyle B Peake
- Group on the Molecular and Cell Biology of Lipids, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
| | | |
Collapse
|
28
|
Xu S, Zhou S, Xia D, Xia J, Chen G, Duan S, Luo J. Defects of synaptic vesicle turnover at excitatory and inhibitory synapses in Niemann-Pick C1-deficient neurons. Neuroscience 2010; 167:608-20. [PMID: 20167265 DOI: 10.1016/j.neuroscience.2010.02.033] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Revised: 02/09/2010] [Accepted: 02/11/2010] [Indexed: 01/27/2023]
Abstract
Niemann-Pick disease type C (NPC) is a progressive neurodegenerative disorder characterized by accumulation of free cholesterol in late endosomes/lysosomes. The pathological basis for the disease is poorly understood. In the present study, electrophysiological and fluorescent dye studies were applied to examine neuron-specific functions of Niemann-Pick disease type C1 (NPC1) and to determine whether excitatory and inhibitory synapses are differentially impaired by NPC1 deficiency. Densities of spines and postsynaptic receptor clusters were not affected by NPC1 deficiency over the period examined. However, drastic defects on exocytosis were found both in glutamatergic and GABAergic synapses. The defects were caused in part by a delay in the time required for replacement of excytosed vesicles with new fusion-competent ones. Moreover, we found that the delay of synaptic vesicle turnover was longer in inhibitory synapses (>3 s) than in excitatory synapses (<0.2 s). These defects may be early indicators, and could provide a potential explanation for key features of the disease, such as dystonia and seizures.
Collapse
Affiliation(s)
- S Xu
- Department of Neurobiology, Institute of Neuroscience, Zhejiang University School of Medicine, Hangzhou, Zhejiang, PR China
| | | | | | | | | | | | | |
Collapse
|
29
|
Claudepierre T, Paques M, Simonutti M, Buard I, Sahel J, Maue RA, Picaud S, Pfrieger FW. Lack of Niemann-Pick type C1 induces age-related degeneration in the mouse retina. Mol Cell Neurosci 2009; 43:164-76. [PMID: 19883762 DOI: 10.1016/j.mcn.2009.10.007] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2009] [Accepted: 10/17/2009] [Indexed: 11/26/2022] Open
Abstract
Niemann-Pick type C (NPC) disease is an inherited lysosomal storage disease and caused by mutations in Npc1 or Npc2, which mediate cooperatively the egress of cholesterol from lysosomes. The disease entails progressive neurodegeneration, whose cause is poorly understood. Here, we report that Npc1 is distributed in distinct layers of the mouse retina and that its deficiency causes striking retinal degeneration in 2-month-old mice with signs of age-related maculopathies. This includes impaired visual function, accumulation of lipofuscin in the retinal pigment epithelium layer, degeneration of photoreceptor outer segments, disruption of synaptic layers and an increase in autophagy markers in the ganglion cell layer. Moreover, the lack of Npc1 results in the upregulation of proteins that mediate cellular cholesterol release in the retina. Our findings suggest that Npc1 is required for normal retinal function and that its absence may serve as model to study age-related degeneration of the retina.
Collapse
Affiliation(s)
- Thomas Claudepierre
- CNRS UPR 3212, University of Strasbourg, Institute of Cellular and Integrative Neurosciences (INCI), 5, rue Blaise Pascal, F-67084 Strasbourg, France
| | | | | | | | | | | | | | | |
Collapse
|
30
|
Abstract
1. Niemann-Pick Type C disease (NPC) is an incurable cholesterol-storage disorder that stems from inherited deficiencies of lysosomal proteins involved in intracellular lipid-trafficking proteins. The condition manifests as progressive neurological impairment and leads to death at an early age. 2. To improve clinical recognization and investigate therapeutic strategies, recent studies using molecular and genetic approaches have led to significant advances in the creation of animal models of NPC, as well as in the understanding of the cellular and molecular mechanisms underlying the pathogenesis of NPC. 3. Patients with NPC are divided into four groups based on age at presentation, whereas the clinical features of NPC can be divided into five categories based on the severity of the disease. Progressive neuronal loss, especially of cerebellar Purkinje cells, is a hallmark of NPC. Ballooned neurons, axonal abnormalities and astroglyosis are among the pathological changes seen. Severe demyelination is also present in the mouse model of NPC. 4. Mutations in the NPC1 gene cause approximately 95% of cases of NPC, whereas mutations in the NPC2 gene account for the remainder of cases. NPC1 is a transmembrane protein and NPC2 is a soluble protein involved in lipid trafficking in lysosomes. Loss-of-function mutations in the NPC1 gene lead to a failure of the calcium-mediated fusion of endosomes with lysosomes, resulting in the accumulation of cholesterol and other lipids in late endosomes and lysosomes. 5. The present review updates the disorders of NPC from clinical features to animal models and molecular mechanisms.
Collapse
Affiliation(s)
- Ying Tang
- Department of Immunology, Molecular Signalling Laboratory, Monash University Central Clinical School, Melbourne, Victoria, Australia
| | | | | |
Collapse
|
31
|
Newell-Litwa K, Salazar G, Smith Y, Faundez V. Roles of BLOC-1 and adaptor protein-3 complexes in cargo sorting to synaptic vesicles. Mol Biol Cell 2009; 20:1441-53. [PMID: 19144828 PMCID: PMC2649275 DOI: 10.1091/mbc.e08-05-0456] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2008] [Revised: 12/23/2008] [Accepted: 01/06/2009] [Indexed: 11/11/2022] Open
Abstract
Neuronal lysosomes and their biogenesis mechanisms are primarily thought to clear metabolites and proteins whose abnormal accumulation leads to neurodegenerative disease pathology. However, it remains unknown whether lysosomal sorting mechanisms regulate the levels of membrane proteins within synaptic vesicles. Using high-resolution deconvolution microscopy, we identified early endosomal compartments where both selected synaptic vesicle and lysosomal membrane proteins coexist with the adaptor protein complex 3 (AP-3) in neuronal cells. From these early endosomes, both synaptic vesicle membrane proteins and characteristic AP-3 lysosomal cargoes can be similarly sorted to brain synaptic vesicles and PC12 synaptic-like microvesicles. Mouse knockouts for two Hermansky-Pudlak complexes involved in lysosomal biogenesis from early endosomes, the ubiquitous isoform of AP-3 (Ap3b1(-/-)) and muted, defective in the biogenesis of lysosome-related organelles complex 1 (BLOC-1), increased the content of characteristic synaptic vesicle proteins and known AP-3 lysosomal proteins in isolated synaptic vesicle fractions. These phenotypes contrast with those of the mouse knockout for the neuronal AP-3 isoform involved in synaptic vesicle biogenesis (Ap3b2(-/-)), in which the content of select proteins was reduced in synaptic vesicles. Our results demonstrate that lysosomal and lysosome-related organelle biogenesis mechanisms regulate steady-state synaptic vesicle protein composition from shared early endosomes.
Collapse
Affiliation(s)
- Karen Newell-Litwa
- *Graduate Program in Biochemistry, Cell, and Developmental Biology
- Department of Cell Biology
| | | | - Yoland Smith
- Department of Neurology, Emory University, Atlanta, GA 30322
| | - Victor Faundez
- Department of Cell Biology
- Center for Neurodegenerative Diseases; and
| |
Collapse
|
32
|
Storch J, Xu Z. Niemann-Pick C2 (NPC2) and intracellular cholesterol trafficking. Biochim Biophys Acta Mol Cell Biol Lipids 2009; 1791:671-8. [PMID: 19232397 DOI: 10.1016/j.bbalip.2009.02.001] [Citation(s) in RCA: 137] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2009] [Revised: 02/03/2009] [Accepted: 02/03/2009] [Indexed: 12/01/2022]
Abstract
Cholesterol is an important precursor for numerous biologically active molecules, and it plays a major role in membrane structure and function. Cholesterol can be endogenously synthesized or exogenously taken up via the endocytic vesicle system and subsequently delivered to post-endo/lysosomal sites including the plasma membrane and the endoplasmic reticulum. Niemann-Pick C (NPC) disease results in the accumulation of exogenously-derived cholesterol, as well as other lipids, in late endosomes and lysosomes (LE/LY). Identification of the two genes that underlie NPC disease, NPC1 and NPC2, has focused attention on the mechanisms by which lipids, in particular cholesterol, are transported out of the LE/LY compartment. This review discusses the role of the NPC2 protein in cholesterol transport, and the potential for concerted action of NPC1 and NPC2 in regulating normal intracellular cholesterol homeostasis.
Collapse
Affiliation(s)
- Judith Storch
- Department of Nutritional Sciences and Rutgers Center for Lipid Research, Rutgers University, New Brunswick, NJ 08901, USA.
| | | |
Collapse
|
33
|
Karten B, Peake KB, Vance JE. Mechanisms and consequences of impaired lipid trafficking in Niemann-Pick type C1-deficient mammalian cells. Biochim Biophys Acta Mol Cell Biol Lipids 2009; 1791:659-70. [PMID: 19416638 DOI: 10.1016/j.bbalip.2009.01.025] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2008] [Accepted: 01/20/2009] [Indexed: 11/18/2022]
Abstract
Niemann-Pick C disease is a fatal progressive neurodegenerative disorder caused in 95% of cases by mutations in the NPC1 gene; the remaining 5% of cases result from mutations in the NPC2 gene. The major biochemical manifestation of NPC1 deficiency is an abnormal sequestration of lipids, including cholesterol and glycosphingolipids, in late endosomes/lysosomes (LE/L) of all cells. In this review, we summarize the current knowledge of the NPC1 protein in mammalian cells with particular focus on how defects in NPC1 alter lipid trafficking and neuronal functions. NPC1 is a protein of LE/L and is predicted to contain thirteen transmembrane domains, five of which constitute a sterol-sensing domain. The precise function of NPC1, and the mechanism by which NPC1 and NPC2 (both cholesterol binding proteins) act together to promote the movement of cholesterol and other lipids out of the LE/L, have not yet been established. Recent evidence suggests that the sequestration of cholesterol in LE/L of cells of the brain (neurons and glial cells) contributes to the widespread death and dysfunction of neurons in the brain. Potential therapies include treatments that promote the removal of cholesterol and glycosphingolipids from LE/L. Currently, the most promising approach for extending life-span and improving the quality of life for NPC patients is a combination of several treatments each of which individually modestly slows disease progression.
Collapse
Affiliation(s)
- Barbara Karten
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada
| | | | | |
Collapse
|
34
|
Transport of LDL-derived cholesterol from the NPC1 compartment to the ER involves the trans-Golgi network and the SNARE protein complex. Proc Natl Acad Sci U S A 2008; 105:16513-8. [PMID: 18946045 DOI: 10.1073/pnas.0807450105] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mammalian cells acquire cholesterol mainly from LDL. LDL enter the endosomes, allowing cholesteryl esters to be hydrolyzed by acid lipase. The hydrolyzed cholesterol (LDL-CHOL) enters the Niemann-Pick type C1 (NPC1)-containing endosomal compartment en route to various destinations. Whether the Golgi is involved in LDL-CHOL transport downstream of the NPC1 compartment has not been demonstrated. Using subcellular fractionation and immunoadsorption to enrich for specific membrane fractions, here we show that, when parental Chinese hamster ovary (CHO) cells are briefly exposed to (3)H-cholesteryl linoleate (CL) labeled-LDL, newly liberated (3)H-LDL-CHOL appears in membranes rich in trans-Golgi network (TGN) long before it becomes available for re-esterification at the endoplasmic reticulum (ER) or for efflux at the plasma membrane. In mutant cells lacking NPC1, the appearance of newly liberated (3)H-LDL-CHOL in the TGN-rich fractions is much reduced. We next report a reconstituted transport system that recapitulates the transport of LDL-CHOL to the TGN and to the ER. The transport system requires ATP and cytosolic factors and depends on functionality of NPC1. We demonstrate that knockdown by RNAi of 3 TGN-specific SNAREs (VAMP4, syntaxin 6, and syntaxin 16) reduces >/=50% of the LDL-CHOL transport in intact cells and in vitro. These results show that vesicular trafficking is involved in transporting a significant portion of LDL-CHOL from the NPC1-containing endosomal compartment to the TGN before its arrival at the ER.
Collapse
|
35
|
Huang X, Warren JT, Buchanan J, Gilbert LI, Scott MP. Drosophila Niemann-Pick type C-2 genes control sterol homeostasis and steroid biosynthesis: a model of human neurodegenerative disease. Development 2007; 134:3733-42. [PMID: 17804599 DOI: 10.1242/dev.004572] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Mutations in either of the two human Niemann-Pick type C (NPC) genes, NPC1 and NPC2, cause a fatal neurodegenerative disease associated with abnormal cholesterol accumulation in cells. npc1a, the Drosophila NPC1 ortholog, regulates sterol homeostasis and is essential for molting hormone (20-hydroxyecdysone; 20E) biosynthesis. While only one npc2 gene is present in yeast, worm, mouse and human genomes, a family of eight npc2 genes (npc2a-h) exists in Drosophila. Among the encoded proteins, Npc2a has the broadest expression pattern and is most similar in sequence to vertebrate Npc2. Mutation of npc2a results in abnormal sterol distribution in many cells, as in Drosophila npc1a or mammalian NPC mutant cells. In contrast to the ecdysteroid-deficient, larval-lethal phenotype of npc1a mutants, npc2a mutants are viable and fertile with relatively normal ecdysteroid level. Mutants in npc2b, another npc2 gene, are also viable and fertile, with no significant sterol distribution abnormality. However, npc2a; npc2b double mutants are not viable but can be rescued by feeding the mutants with 20E or cholesterol, the basic precursor of 20E. We conclude that npc2a functions redundantly with npc2b in regulating sterol homeostasis and ecdysteroid biosynthesis, probably by controlling the availability of sterol substrate. Moreover, npc2a; npc2b double mutants undergo apoptotic neurodegeneration, thus constituting a new fly model of human neurodegenerative disease.
Collapse
Affiliation(s)
- Xun Huang
- Department of Developmental Biology, Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305-5439, USA
| | | | | | | | | |
Collapse
|
36
|
Patterson MC, Vecchio D, Prady H, Abel L, Wraith JE. Miglustat for treatment of Niemann-Pick C disease: a randomised controlled study. Lancet Neurol 2007; 6:765-72. [PMID: 17689147 DOI: 10.1016/s1474-4422(07)70194-1] [Citation(s) in RCA: 410] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND Niemann-Pick type C disease (NPC) is an inherited neurodegenerative disorder characterised by an intracellular lipid-trafficking defect with secondary accumulation of glycosphingolipids. Miglustat, a small iminosugar, reversibly inhibits glucosylceramide synthase, which catalyses the first committed step of glycosphingolipid synthesis. Miglustat is able to cross the blood-brain barrier, and is thus a potential therapy for neurological diseases. We aimed to establish the effect of miglustat on several markers of NPC severity. METHODS Patients aged 12 years or older who had NPC (n=29) were randomly assigned to receive either miglustat 200 mg three times a day (n=20) or standard care (n=9) for 12 months. 12 children younger than 12 years of age were included in an additional cohort; all received miglustat at a dose adjusted for body surface area. All participants were then treated with miglustat for an additional year in an extension study. The primary endpoint was horizontal saccadic eye movement (HSEM) velocity, based on its correlation with disease progression. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN26761144. FINDINGS At 12 months, HSEM velocity had improved in patients treated with miglustat versus those receiving standard care; results were significant when patients taking benzodiazepines were excluded (p=0.028). Children showed an improvement in HSEM velocity of similar size at 12 months. Improvement in swallowing capacity, stable auditory acuity, and a slower deterioration in ambulatory index were also seen in treated patients older than 12 years. The safety and tolerability of miglustat 200 mg three times a day in study participants was consistent with previous trials in type I Gaucher disease, where half this dose was used. INTERPRETATION Miglustat improves or stabilises several clinically relevant markers of NPC. This is the first agent studied in NPC for which there is both animal and clinical data supporting a disease modifying benefit.
Collapse
Affiliation(s)
- Marc C Patterson
- Department of Neurology and Pediatrics, Columbia University, NY, USA.
| | | | | | | | | |
Collapse
|
37
|
Voght SP, Fluegel ML, Andrews LA, Pallanck LJ. Drosophila NPC1b promotes an early step in sterol absorption from the midgut epithelium. Cell Metab 2007; 5:195-205. [PMID: 17339027 DOI: 10.1016/j.cmet.2007.01.011] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2006] [Revised: 12/04/2006] [Accepted: 01/23/2007] [Indexed: 11/20/2022]
Abstract
The NPC1 family of proteins plays crucial roles in the intestinal absorption and intracellular trafficking of sterols. The Drosophila genome encodes two NPC1 homologs, one of which, NPC1a, is required for intracellular sterol trafficking in many tissues. Here we show that the other Drosophila NPC1 family member, NPC1b, is expressed in the midgut epithelium and that NPC1b is essential for growth during the early larval stages of development. NPC1b mutants are severely defective in sterol absorption, and the midgut epithelium of NPC1b mutants is deficient in sterols and sterol trafficking intermediates. By contrast, NPC1a mutants absorb sterols more efficiently than wild-type animals, and, unexpectedly, NPC1b;NPC1a double mutants absorb sterols as efficiently as wild-type animals. Together, these findings suggest that NPC1b plays an early role in sterol absorption, although sterol absorption continues at high efficiency through an NPC1a- and NPC1b-independent mechanism under conditions of impaired intracellular sterol trafficking.
Collapse
Affiliation(s)
- Stephen P Voght
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | | | | | | |
Collapse
|
38
|
Wasser CR, Ertunc M, Liu X, Kavalali ET. Cholesterol-dependent balance between evoked and spontaneous synaptic vesicle recycling. J Physiol 2006; 579:413-29. [PMID: 17170046 PMCID: PMC2075401 DOI: 10.1113/jphysiol.2006.123133] [Citation(s) in RCA: 123] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Cholesterol is a prominent component of nerve terminals. To examine cholesterol's role in central neurotransmission, we treated hippocampal cultures with methyl-beta-cyclodextrin, which reversibly binds cholesterol, or mevastatin, an inhibitor of cholesterol biosynthesis, to deplete cholesterol. We also used hippocampal cultures from Niemann-Pick type C1-deficient mice defective in intracellular cholesterol trafficking. These conditions revealed an augmentation in spontaneous neurotransmission detected electrically and an increase in spontaneous vesicle endocytosis judged by horseradish peroxidase uptake after cholesterol depletion by methyl-beta-cyclodextrin. In contrast, responses evoked by action potentials and hypertonicity were severely impaired after the same treatments. The increase in spontaneous vesicle recycling and the decrease in evoked neurotransmission were reversible upon cholesterol addition. Cholesterol removal did not impact on the low level of evoked neurotransmission seen in the absence of synaptic vesicle SNARE protein synaptobrevin-2 whereas the increase in spontaneous fusion remained. These results suggest that synaptic cholesterol balances evoked and spontaneous neurotransmission by hindering spontaneous synaptic vesicle turnover and sustaining evoked exo-endocytosis.
Collapse
Affiliation(s)
- Catherine R Wasser
- Center for Basic Neuroscience, The University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-9111, USA
| | | | | | | |
Collapse
|
39
|
Jacobs ME, DeSouza LV, Samaranayake H, Pearlman RE, Siu KWM, Klobutcher LA. The Tetrahymena thermophila phagosome proteome. EUKARYOTIC CELL 2006; 5:1990-2000. [PMID: 17012537 PMCID: PMC1694822 DOI: 10.1128/ec.00195-06] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2006] [Accepted: 09/21/2006] [Indexed: 12/22/2022]
Abstract
In vertebrates, phagocytosis occurs mainly in specialized cells of the immune system and serves as a primary defense against invading pathogens, but it also plays a role in clearing apoptotic cells and in tissue remodeling during development. In contrast, unicellular eukaryotes, such as the ciliate Tetrahymena thermophila, employ phagocytosis to ingest and degrade other microorganisms to meet their nutritional needs. To learn more about the protein components of the multistep process of phagocytosis, we carried out an analysis of the Tetrahymena phagosome proteome. Tetrahymena cells were fed polystyrene beads, which allowed for the efficient purification of phagosomes. The protein composition of purified phagosomes was then analyzed by multidimensional separation coupled with tandem mass spectrometry. A total of 453 peptides were identified that resulted in the identification of 73 putative phagosome proteins. Twenty-eight of the proteins have been implicated in phagocytosis in other organisms, indicating that key aspects of phagocytosis were conserved during evolution. Other identified proteins have not previously been associated with phagocytosis, including some of unknown function. Live-cell confocal fluorescence imaging of Tetrahymena strains expressing green fluorescent protein-tagged versions of four of the identified phagosome proteins provided evidence that at least three of the proteins (including two with unknown functions) are associated with phagosomes, indicating that the bulk of the proteins identified in the analyses are indeed phagosome associated.
Collapse
Affiliation(s)
- Mary Ellen Jacobs
- Department of Molecular, Microbial and Structural Biology, University of Connecticut Health Center, Farmington, CT 06032, USA
| | | | | | | | | | | |
Collapse
|
40
|
Gorgas K, Teigler A, Komljenovic D, Just WW. The ether lipid-deficient mouse: Tracking down plasmalogen functions. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2006; 1763:1511-26. [PMID: 17027098 DOI: 10.1016/j.bbamcr.2006.08.038] [Citation(s) in RCA: 157] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2006] [Revised: 08/15/2006] [Accepted: 08/23/2006] [Indexed: 10/24/2022]
Abstract
Chemical and physico-chemical properties as well as physiological functions of major mammalian ether-linked glycerolipids, including plasmalogens were reviewed. Their chemical structures were described and their effect on membrane fluidity and membrane fusion discussed. The recent generation of mouse models with ether lipid deficiency offered the possibility to study ether lipid and particularly plasmalogen functions in vivo. Ether lipid-deficient mice revealed severe phenotypic alterations, including arrest of spermatogenesis, development of cataract and defects in central nervous system myelination. In several cell culture systems lack of plasmalogens impaired intracellular cholesterol distribution affecting plasma membrane functions and structural changes of ER and Golgi cisternae. Based on these phenotypic anomalies that were accurately described conclusions were drawn on putative functions of plasmalogens. These functions were related to cell-cell or cell-extracellular matrix interactions, formation of lipid raft microdomains and intracellular cholesterol homeostasis. There are several human disorders, such as Zellweger syndrome, rhizomelic chondrodysplasia punctata, Alzheimer's disease, Down syndrome, and Niemann-Pick type C disease that are distinguished by altered tissue plasmalogen concentrations. The role plasmalogens might play in the pathology of these disorders is discussed.
Collapse
Affiliation(s)
- Karin Gorgas
- Institut für Anatomie und Zellbiologie, Abteilung Medizinische Zellbiologie, Im Neuenheimer Feld 307, D-69120 Heidelberg, Germany
| | | | | | | |
Collapse
|
41
|
Abstract
Compared with other organs, the brain is highly enriched in cholesterol. Essentially all cholesterol in the brain is synthesized within the brain; the blood-brain barrier prevents the import of plasma lipoproteins into the brain. Consequently, the brain operates an independent lipoprotein transport system in which glial cells produce ApoE (apolipoprotein E)-containing lipoproteins that are thought to deliver cholesterol to neurons for axonal growth and repair. We have shown that ApoE-containing lipoproteins generated by glial cells stimulate axon extension. ApoE associated with lipoprotein particles, and a receptor of the low-density lipoprotein receptor family, are required for stimulation of axon growth. NPC (Niemann-Pick type C) disease is a severe neurological disorder caused by mutations in the NPC1 or NPC2 gene. A hallmark of this disease is impaired transport of cholesterol out of late endosomes/lysosomes and the accumulation of cholesterol in these organelles. Although cholesterol accumulates in cell bodies of neurons from NPC1-deficient mice, the cholesterol content of axons is reduced. The presence of NPC1 in endosomal structures in nerve terminals, and the finding of aberrant synaptic vesicles, suggest that defects in synaptic vesicle recycling contribute to neurological abnormalities characteristic of NPC disease. We have also shown that ApoE-containing lipoproteins produced by glial cells from NCP1-deficient mice are of normal composition and stimulate axon extension.
Collapse
Affiliation(s)
- J E Vance
- Canadian Institutes for Health Research Group on the Molecular and Cell Biology of Lipids, University of Alberta, Edmonton.
| | | | | |
Collapse
|
42
|
Vance JE. Lipid imbalance in the neurological disorder, Niemann-Pick C disease. FEBS Lett 2006; 580:5518-24. [PMID: 16797010 DOI: 10.1016/j.febslet.2006.06.008] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2006] [Revised: 05/29/2006] [Accepted: 06/01/2006] [Indexed: 10/24/2022]
Abstract
Niemann-Pick C (NPC) disease is a progressive neurological disorder in which cholesterol, gangliosides and bis-monoacylglycerol phosphate accumulate in late endosomes/lysosomes. This disease is caused by mutations in either the NPC1 or NPC2 gene. NPC1 and NPC2 are involved in egress of lipids, particularly cholesterol, from late endosomes/lysosomes but the precise functions of these proteins are not clear. An important question regarding the function of NPC proteins is: why do mutations in these ubiquitously expressed proteins have such dire consequences in the brain? This review summarizes the roles of NPC proteins in lipid homeostasis particularly in the central nervous system.
Collapse
Affiliation(s)
- Jean E Vance
- Canadian Institutes for Health Research Group on the Molecular and Cell Biology of Lipids, Department of Medicine, 332 HMRC, University of Alberta, Edmonton, Alta., Canada T6G 2S2.
| |
Collapse
|