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Martinez AE, Weissberger G, Kuklenyik Z, He X, Meuret C, Parekh T, Rees JC, Parks BA, Gardner MS, King SM, Collier TS, Harrington MG, Sweeney MD, Wang X, Zlokovic BV, Joe E, Nation DA, Schneider LS, Chui HC, Barr JR, Han SD, Krauss RM, Yassine HN. The small HDL particle hypothesis of Alzheimer's disease. Alzheimers Dement 2023; 19:391-404. [PMID: 35416404 PMCID: PMC10563117 DOI: 10.1002/alz.12649] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 02/08/2022] [Accepted: 02/12/2022] [Indexed: 01/03/2023]
Abstract
We propose the hypothesis that small high-density lipoprotein (HDL) particles reduce the risk of Alzheimer's disease (AD) by virtue of their capacity to exchange lipids, affecting neuronal membrane composition and vascular and synaptic functions. Concentrations of small HDLs in cerebrospinal fluid (CSF) and plasma were measured in 180 individuals ≥60 years of age using ion mobility methodology. Small HDL concentrations in CSF were positively associated with performance in three domains of cognitive function independent of apolipoprotein E (APOE) ε4 status, age, sex, and years of education. Moreover, there was a significant correlation between levels of small HDLs in CSF and plasma. Further studies will be aimed at determining whether specific components of small HDL exchange across the blood, brain, and CSF barriers, and developing approaches to exploit small HDLs for therapeutic purposes.
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Affiliation(s)
- Ashley E. Martinez
- Department of Medicine, University of Southern California, Los Angeles, California, USA
| | - Gali Weissberger
- The Interdisciplinary Department of Social Sciences, Bar Ilan University, Israel
| | - Zsuzsanna Kuklenyik
- Clinical Chemistry Branch, Division of Laboratory Sciences, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Xulei He
- Department of Medicine, University of Southern California, Los Angeles, California, USA
| | - Cristiana Meuret
- Department of Medicine, University of Southern California, Los Angeles, California, USA
| | - Trusha Parekh
- Department of Medicine, University of Southern California, Los Angeles, California, USA
| | - Jon C. Rees
- Clinical Chemistry Branch, Division of Laboratory Sciences, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Bryan A. Parks
- Clinical Chemistry Branch, Division of Laboratory Sciences, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Michael S. Gardner
- Clinical Chemistry Branch, Division of Laboratory Sciences, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Sarah M. King
- Departments of Pediatrics and Medicine, University of California, San Francisco, California, USA
| | | | - Michael G. Harrington
- Department of Neurology, University of Southern California, Los Angeles, California, USA
| | - Melanie D. Sweeney
- Department of Physiology and Neuroscience, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, California, USA
| | - Xinhui Wang
- Department of Neurology, University of Southern California, Los Angeles, California, USA
| | - Berislav V. Zlokovic
- Department of Physiology and Neuroscience, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, California, USA
| | - Elizabeth Joe
- Department of Neurology, University of Southern California, Los Angeles, California, USA
| | - Daniel A. Nation
- Irvine, Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, California, USA
| | - Lon S. Schneider
- Department of Neurology, University of Southern California, Los Angeles, California, USA
- Department of Psychiatry and Behavioral Sciences, University of Southern California, Los Angeles, California, USA
| | - Helena C. Chui
- Department of Neurology, University of Southern California, Los Angeles, California, USA
| | - John R. Barr
- Clinical Chemistry Branch, Division of Laboratory Sciences, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - S. Duke Han
- Department of Family Medicine, University of Southern California, Los Angeles, California, USA
| | - Ronald M. Krauss
- Departments of Pediatrics and Medicine, University of California, San Francisco, California, USA
| | - Hussein N. Yassine
- Department of Medicine, University of Southern California, Los Angeles, California, USA
- Department of Neurology, University of Southern California, Los Angeles, California, USA
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Asante I, Louie S, Yassine HN. Uncovering mechanisms of brain inflammation in Alzheimer's disease with APOE4: Application of single cell-type lipidomics. Ann N Y Acad Sci 2022; 1518:84-105. [PMID: 36200578 PMCID: PMC10092192 DOI: 10.1111/nyas.14907] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A chronic state of unresolved inflammation in Alzheimer's disease (AD) is intrinsically involved with the remodeling of brain lipids. This review highlights the effect of carrying the apolipoprotein E ε4 allele (APOE4) on various brain cell types in promoting an unresolved inflammatory state. Among its pleotropic effects on brain lipids, we focus on APOE4's activation of Ca2+ -dependent phospholipase A2 (cPLA2) and its effects on arachidonic acid, eicosapentaenoic acid, and docosahexaenoic acid signaling cascades in the brain. During the process of neurodegeneration, various brain cell types, such as astrocytes, microglia, and neurons, together with the neurovascular unit, develop distinct inflammatory phenotypes that impact their functions and have characteristic lipidomic fingerprints. We propose that lipidomic phenotyping of single cell-types harvested from brains differing by age, sex, disease severity stage, and dietary and genetic backgrounds can be employed to probe mechanisms of neurodegeneration. A better understanding of the brain cellular inflammatory/lipidomic response promises to guide the development of nutritional and drug interventions for AD dementia.
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Affiliation(s)
- Isaac Asante
- Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Stan Louie
- School of Pharmacy, University of Southern California, Los Angeles, California, USA
| | - Hussein N Yassine
- Keck School of Medicine, University of Southern California, Los Angeles, California, USA
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3
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ApoE4 Impairs Neuron-Astrocyte Coupling of Fatty Acid Metabolism. Cell Rep 2021; 34:108572. [PMID: 33406436 PMCID: PMC7837265 DOI: 10.1016/j.celrep.2020.108572] [Citation(s) in RCA: 133] [Impact Index Per Article: 44.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 11/16/2020] [Accepted: 12/08/2020] [Indexed: 01/01/2023] Open
Abstract
Alzheimer’s disease (AD) risk gene ApoE4 perturbs brain lipid homeostasis and energy transduction. However, the cell-type-specific mechanism of ApoE4 in modulating brain lipid metabolism is unclear. Here, we describe a detrimental role of ApoE4 in regulating fatty acid (FA) metabolism across neuron and astrocyte in tandem with their distinctive mitochondrial phenotypes. ApoE4 disrupts neuronal function by decreasing FA sequestering in lipid droplets (LDs). FAs in neuronal LDs are exported and internalized by astrocytes, with ApoE4 diminishing the transport efficiency. Further, ApoE4 lowers FA oxidation and leads to lipid accumulation in both astrocyte and the hippocampus. Importantly, diminished capacity of ApoE4 astrocytes in eliminating neuronal lipids and degrading FAs accounts for their compromised metabolic and synaptic support to neurons. Collectively, our findings reveal a mechanism of ApoE4 disruption to brain FA and bioenergetic homeostasis that could underlie the accelerated lipid dysregulation and energy deficits and increased AD risk for ApoE4 carriers. Qi et al. reveal a role of Alzheimer’s disease risk gene ApoE4 in disrupting fatty acid metabolism coupled between neuron and astrocyte. A systematic impairment in neuronal sequestering, neuron-to-astrocyte transport, and astrocytic degradation of fatty acids could contribute to lipid dysregulation, bioenergetic deficits, and increased Alzheimer’s risk in ApoE4 carriers.
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Plasma membrane localization of the GFL receptor components: a nexus for receptor crosstalk. Cell Tissue Res 2020; 382:57-64. [PMID: 32767110 PMCID: PMC7529631 DOI: 10.1007/s00441-020-03235-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 06/04/2020] [Indexed: 12/26/2022]
Abstract
The glial cell line-derived neurotrophic factor (GDNF) family ligands (GFLs) comprise a group of four homologous and potent growth factors that includes GDNF, neurturin (NRTN), artemin (ARTN), and persephin (PSPN). The survival, growth, and mitotic activities of the GFLs are conveyed by a single receptor tyrosine kinase, Ret. The GFLs do not bind directly to Ret in order to activate it, and instead bind with high affinity to glycerophosphatidylinositol (GPI)-anchored coreceptors called the GDNF family receptor-αs (GFRαs). Several mechanisms have recently been identified that influence the trafficking of Ret and GFRαs in and out of the plasma membrane, thereby affecting their availability for ligand binding, as well as their levels by targeting to degradative pathways. This review describes these mechanisms and their powerful effects on GFL signaling and function. We also describe the recent discovery that p75 and Ret form a signaling complex, also regulated by plasma membrane shuttling, that either enhances GFL survival signals or p75 pro-apoptotic signals, dependent on the cellular context.
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Cipollari E, Szapary HJ, Picataggi A, Billheimer JT, Lyssenko CA, Ying GS, Shaw LM, Kling MA, Kaddurah-Daouk R, Rader DJ, Pratico D, Lyssenko NN. Correlates and Predictors of Cerebrospinal Fluid Cholesterol Efflux Capacity from Neural Cells, a Family of Biomarkers for Cholesterol Epidemiology in Alzheimer's Disease. J Alzheimers Dis 2020; 74:563-578. [PMID: 32065798 PMCID: PMC7333913 DOI: 10.3233/jad-191246] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Basic research has implicated intracellular cholesterol in neurons, microglia, and astrocytes in the pathogenesis of Alzheimer's disease (AD), but there is presently no assay to access intracellular cholesterol in neural cells in living people in the context of AD. OBJECTIVE To devise and characterize an assay that can access intracellular cholesterol and cholesterol efflux in neural cells in living subjects. METHODS We modified the protocol for high-density lipoprotein cholesterol efflux capacity (CEC) from macrophages, a biomarker that accesses cholesterol in macrophages in atherosclerosis. To measure cerebrospinal fluid (CSF) CECs from neurons, microglia, and astrocytes, CSF was exposed to, correspondingly, neuronal, microglial, and astrocytic cholesterol source cells. Human neuroblastoma SH-SY5Y, mouse microglial N9, and human astroglial A172 cells were used as the cholesterol source cells. CSF samples were screened for contamination with blood. CSF CECs were measured in a small cohort of 22 individuals. RESULTS CSF CECs from neurons, microglia, and astrocytes were moderately to moderately strongly correlated with CSF concentrations of cholesterol, apolipoprotein A-I, apolipoprotein E, and clusterin (Pearson's r = 0.53-0.86), were in poor agreement with one another regarding CEC of the CSF samples (Lin's concordance coefficient rc = 0.71-0.76), and were best predicted by models consisting of, correspondingly, CSF phospholipid (R2 = 0.87, p < 0.0001), CSF apolipoprotein A-I and clusterin (R2 = 0.90, p < 0.0001), and CSF clusterin (R2 = 0.62, p = 0.0005). CONCLUSION Characteristics of the CSF CEC metrics suggest a potential for independent association with AD and provision of fresh insight into the role of cholesterol in AD pathogenesis.
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Affiliation(s)
- Eleonora Cipollari
- Division of Translational Medicine and Human Genetics, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Hannah J. Szapary
- Division of Translational Medicine and Human Genetics, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Antonino Picataggi
- Division of Translational Medicine and Human Genetics, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Jeffrey T. Billheimer
- Division of Translational Medicine and Human Genetics, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Catherine A. Lyssenko
- Office of Institutional Research & Analysis, University of Pennsylvania, Philadelphia, PA, USA
| | - Gui-Shuang Ying
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Leslie M. Shaw
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Mitchel A. Kling
- Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
- Behavioral Health Services, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA, USA
| | - Rima Kaddurah-Daouk
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, NC, USA
- Duke Institute for Brain Sciences, Duke University, Durham, NC, USA
- Department of Medicine, Duke University School of Medicine, Durham, NC, USA
| | - Daniel J. Rader
- Division of Translational Medicine and Human Genetics, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Domenico Pratico
- Alzheimer’s Center at Temple, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Nicholas N. Lyssenko
- Alzheimer’s Center at Temple, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
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Toro CA, Das DK, Cai D, Cardozo CP. Elucidating the Role of Apolipoprotein E Isoforms in Spinal Cord Injury-Associated Neuropathology. J Neurotrauma 2019; 36:3317-3322. [PMID: 31218915 DOI: 10.1089/neu.2018.6334] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Spinal cord injury (SCI) is a devastating, life-altering, neurological event that affects ∼300,000 individuals in the United States. Currently, there are no effective treatments to reverse the neurological impairments caused by the lesion. Until a cure is available, there is an urgent need for strategies that can either spare injured neurons or promote neuroplasticity and functional recovery. Genetic links to outcomes after SCI may provide insights into the pathological mechanisms, and possible new avenues for drug development. In the present review, we discuss the current knowledge linking apolipoprotein E genotypes with better or worse functional outcomes after an SCI, and the possible molecular mechanisms that may contribute to this association.
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Affiliation(s)
- Carlos A Toro
- National Center for the Medical Consequences of Spinal Cord Injury, James J. Peters VA, Bronx, New York
- Department of Medicine, Icahn School of Medicine at Mount Sinai, Bronx, New York
| | - Dibash K Das
- National Center for the Medical Consequences of Spinal Cord Injury, James J. Peters VA, Bronx, New York
- Department of Medicine, Icahn School of Medicine at Mount Sinai, Bronx, New York
| | - Dongming Cai
- Neurology Service, James J. Peters VA, Bronx, New York
- Department of Neurology, Icahn School of Medicine at Mount Sinai, Bronx, New York
| | - Christopher P Cardozo
- National Center for the Medical Consequences of Spinal Cord Injury, James J. Peters VA, Bronx, New York
- Department of Medicine, Icahn School of Medicine at Mount Sinai, Bronx, New York
- Department of Rehabilitative Medicine, Icahn School of Medicine at Mount Sinai, Bronx, New York
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7
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Ryu JR, Kim JH, Cho HM, Jo Y, Lee B, Joo S, Chae U, Nam Y, Cho IJ, Sun W. A monitoring system for axonal growth dynamics using micropatterns of permissive and Semaphorin 3F chemorepulsive signals. LAB ON A CHIP 2019; 19:291-305. [PMID: 30539180 DOI: 10.1039/c8lc00845k] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Neurons reach their correct targets by directional outgrowth of axons, which is mediated by attractive or repulsive cues. Growing axons occasionally cross a field of repulsive cues and stop at intermediate targets on the journey to their final destination. However, it is not well-understood how individual growth cones make decisions, and pass through repulsive territory to reach their permissive target regions. We developed a microcontact printing culture system that could trap individual axonal tips in a permissive dot area surrounded by the repulsive signal, semaphorin 3F (Sema3F). Axons of rat hippocampal neurons on the Sema3F/PLL dot array extended in the checkboard pattern with a significantly slow growth rate. The detailed analysis of the behaviors of axonal growth cones revealed the saccadic dynamics in the dot array system. The trapped axonal tips in the permissive area underwent growth cone enlargement with remarkably spiky filopodia, promoting their escape from the Sema3F constraints with straight extension of axons. This structured axonal growth on the dot pattern was disrupted by increased inter-dot distance, or perturbing intracellular signaling machineries. These data indicate that axons grow against repulsive signals by jumping over the repulsive cues, depending on contact signals and intracellular milieu. Our study suggests that our dot array culture system can be used as a screening system to easily and efficiently evaluate ECM or small molecule inhibitors interfering growth cone dynamics leading to controlling axonal growth.
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Affiliation(s)
- Jae Ryun Ryu
- Department of Anatomy, Brain Korea 21, Korea University College of Medicine, Anam-Dong, Sungbuk-Gu, Seoul, 136-705, Republic of Korea.
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8
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Spagnuolo MS, Donizetti A, Iannotta L, Aliperti V, Cupidi C, Bruni AC, Cigliano L. Brain-derived neurotrophic factor modulates cholesterol homeostasis and Apolipoprotein E synthesis in human cell models of astrocytes and neurons. J Cell Physiol 2018; 233:6925-6943. [PMID: 29323721 DOI: 10.1002/jcp.26480] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 01/05/2018] [Indexed: 12/12/2022]
Abstract
In the central nervous system, cholesterol is critical to maintain membrane plasticity, cellular function, and synaptic integrity. In recent years, much attention was focused on the role of cholesterol in brain since a breakdown of cholesterol metabolism has been associated with different diseases. Brain-derived neurotrophic factor (BDNF) was previously reported to elicit cholesterol biosynthesis and promote the accumulation of presynaptic proteins in cholesterol-rich lipid rafts, but no data are available on its ability to modulate physiological mechanisms involved in cholesterol homeostasis. Major aim of this research was to investigate whether BDNF influences cholesterol homeostasis, focusing on the effect of the neurotrophin on Apolipoprotein E (ApoE) synthesis, cholesterol efflux from astrocytes and cholesterol incorporation into neurons. Our results show that BDNF significantly stimulates cholesterol efflux by astrocytes, as well as ATP binding cassette A1 (ABCA1) transporter and ApoE expression. Conversely, cholesterol uptake in neurons was downregulated by BDNF. This effect was associated with the increase of Liver X Receptor (LXR)-beta expression in neuron exposed to BDNF. The level of apoptosis markers, that is, cleaved caspase 3 and poly ADP ribose polymerase (PARP), was found increased in neurons treated with high cholesterol, but significantly lower when the cells were exposed to cholesterol in the presence of BDNF, thus suggesting a neuroprotective role of the neurotrophin, likely through its reducing effect of neuronal cholesterol uptake. Interestingly, cholesterol stimulates BDNF production by neurons. Overall, our findings evidenced a novel role of BDNF in the modulation of ApoE and cholesterol homeostasis in glial and neuronal cells.
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Affiliation(s)
- Maria S Spagnuolo
- Department of Bio-Agrofood Science, Institute for the Animal Production System in Mediterranean Environment, National Research Council, Naples, Italy
| | - Aldo Donizetti
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Lucia Iannotta
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Vincenza Aliperti
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Chiara Cupidi
- Centro Regionale di Neurogenetica, via Perugini, ASP Catanzaro, Lamezia Terme (CZ), Italy
| | - Amalia C Bruni
- Centro Regionale di Neurogenetica, via Perugini, ASP Catanzaro, Lamezia Terme (CZ), Italy
| | - Luisa Cigliano
- Department of Biology, University of Naples Federico II, Naples, Italy
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9
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Nienov OH, Matte L, Dias LS, Schmid H. Peripheral polyneuropathy in severely obese patients with metabolic syndrome but without diabetes: Association with low HDL-cholesterol. Rev Assoc Med Bras (1992) 2017; 63:324-331. [DOI: 10.1590/1806-9282.63.04.324] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 12/01/2016] [Indexed: 11/22/2022] Open
Abstract
Summary Introduction: The purpose of this study was to evaluate the prevalence of peripheral polyneuropathy (PPN) in subjects with grade II and III obesity (Ob-II,III) and metabolic syndrome (MetS) but without diabetes and to investigate possible associated factors. Method: A cross-sectional study was performed in non-diabetic Ob-II,III,MetS patients using the Michigan Neuropathy Screening Instrument (MNSI) to assess the presence of PPN. Results: A total of 24 of 218 non-diabetic Ob-II,III,MetS patients had PPN. Based on univariate analysis, serum levels of LDL-cholesterol (p=0.046) were significantly associated with PPN, while serum triglycerides (p=0.118) and low HDL-cholesterol (p=0.057) showed a tendency toward this association. On a Poisson regression analysis, when the three possible associations were included, low HDL-cholesterol (p=0.047) remained independently associated. Conclusion: In non-diabetic Ob-II,III,MetS patients, PPN defined by the MNSI showed a high prevalence and was associated with low levels of HDL-cholesterol. In order to diagnose that complication, neurological evaluation should be performed in these patients.
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Affiliation(s)
| | - Luciana Matte
- Universidade Federal de Ciências da Saúde de Porto Alegre, Brazil
| | - Lisiane Stefani Dias
- Universidade Federal do Rio Grande do Sul, Brazil; Universidade Federal de Ciências da Saúde de Porto Alegre, Brazil
| | - Helena Schmid
- Universidade Federal do Rio Grande do Sul, Brazil; Universidade Federal de Ciências da Saúde de Porto Alegre, Brazil; Hospital de Clínica de Porto Alegre, Brazil; Complexo Hospitalar Santa Casa de Misericórdia de Porto Alegre, Brazil
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10
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Serum protein changes in a rat model of chronic pain show a correlation between animal and humans. Sci Rep 2017; 7:41723. [PMID: 28145509 PMCID: PMC5286399 DOI: 10.1038/srep41723] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 01/03/2017] [Indexed: 01/02/2023] Open
Abstract
In previous works we showed the overexpression of some proteins in biological fluids from patients suffering chronic pain. In this proteomic study we analysed serum from a rat model of neuropathic pain obtained by the chronic constriction injury (CCI) of sciatic nerve, at two time intervals, 2 and 5 weeks after the insult, to find proteins involved in the expression or mediation of pain. Sham-operated and CCI rats were treated with saline or indomethacin. Two weeks after ligation, we identified three serum proteins overexpressed in CCI rats, two of which, alpha-1-macroglobulin and vitamin D-binding protein (VDBP), remained increased 5 weeks post-surgery; at this time interval, we found increased levels of further proteins, namely apolipoprotein A-I (APOA1), apolipoprotein E (APOE), prostaglandin-H2 D-isomerase (PTGDS) and transthyretin (TTR), that overlap the overexpressed proteins found in humans. Indomethacin treatment reversed the effects of ligation. The qPCR analysis showed that transcript levels of APOA1, APOE, PTGDS and VDBP were overexpressed in the lumbar spinal cord (origin of sciatic nerve), but not in the striatum (an unrelated brain region), of CCI rats treated with saline 5 weeks after surgery, demonstrating that the lumbar spinal cord is a possible source of these proteins.
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11
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Yi S, Zhang H, Gong L, Wu J, Zha G, Zhou S, Gu X, Yu B. Deep Sequencing and Bioinformatic Analysis of Lesioned Sciatic Nerves after Crush Injury. PLoS One 2015; 10:e0143491. [PMID: 26629691 PMCID: PMC4668002 DOI: 10.1371/journal.pone.0143491] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2015] [Accepted: 11/05/2015] [Indexed: 11/18/2022] Open
Abstract
The peripheral nerve system has an intrinsic regenerative capacity in response to traumatic injury. To better understand the molecular events occurring after peripheral nerve injury, in the current study, a rat model of sciatic nerve crush injury was used. Injured nerves harvested at 0, 1, 4, 7, and 14 days post injury were subjected to deep RNA sequencing for examining global gene expression changes. According to the temporally differential expression patterns of a huge number of genes, 3 distinct phases were defined within the post-injury period of 14 days: the acute, sub-acute, and post-acute stages. Each stage showed its own characteristics of gene expression, which were associated with different categories of diseases and biological functions and canonical pathways. Ingenuity pathway analysis revealed that genes involved in inflammation and immune response were significantly up-regulated in the acute phase, and genes involved in cellular movement, development, and morphology were up-regulated in the sub-acute stage, while the up-regulated genes in the post-acute phase were mainly involved in lipid metabolism, cytoskeleton reorganization, and nerve regeneration. All the data obtained in the current study may help to elucidate the molecular mechanisms underlying peripheral nerve regeneration from the perspective of gene regulation, and to identify potential therapeutic targets for the treatment of peripheral nerve injury.
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Affiliation(s)
- Sheng Yi
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, China
| | - Honghong Zhang
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, China
| | - Leilei Gong
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, China
| | - Jiancheng Wu
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, China
| | - Guangbin Zha
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, China
| | - Songlin Zhou
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, China
| | - Xiaosong Gu
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, China
| | - Bin Yu
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, China
- * E-mail:
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12
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Djelti F, Braudeau J, Hudry E, Dhenain M, Varin J, Bièche I, Marquer C, Chali F, Ayciriex S, Auzeil N, Alves S, Langui D, Potier MC, Laprevote O, Vidaud M, Duyckaerts C, Miles R, Aubourg P, Cartier N. CYP46A1 inhibition, brain cholesterol accumulation and neurodegeneration pave the way for Alzheimer's disease. Brain 2015; 138:2383-98. [PMID: 26141492 DOI: 10.1093/brain/awv166] [Citation(s) in RCA: 142] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 04/17/2015] [Indexed: 12/20/2022] Open
Abstract
Abnormalities in neuronal cholesterol homeostasis have been suspected or observed in several neurodegenerative disorders including Alzheimer's disease, Parkinson's disease and Huntington's disease. However, it has not been demonstrated whether an increased abundance of cholesterol in neurons in vivo contributes to neurodegeneration. To address this issue, we used RNA interference methodology to inhibit the expression of cholesterol 24-hydroxylase, encoded by the Cyp46a1 gene, in the hippocampus of normal mice. Cholesterol 24-hydroxylase controls cholesterol efflux from the brain and thereby plays a major role in regulating brain cholesterol homeostasis. We used an adeno-associated virus vector encoding short hairpin RNA directed against the mouse Cyp46a1 mRNA to decrease the expression of the Cyp46a1 gene in hippocampal neurons of normal mice. This increased the cholesterol concentration in neurons, followed by cognitive deficits and hippocampal atrophy due to apoptotic neuronal death. Prior to neuronal death, the recruitment of the amyloid protein precursor to lipid rafts was enhanced leading to the production of β-C-terminal fragment and amyloid-β peptides. Abnormal phosphorylation of tau and endoplasmic reticulum stress were also observed. In the APP23 mouse model of Alzheimer's disease, the abundance of amyloid-β peptides increased following inhibition of Cyp46a1 expression, and neuronal death was more widespread than in normal mice. Altogether, these results suggest that increased amounts of neuronal cholesterol within the brain may contribute to inducing and/or aggravating Alzheimer's disease.
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Affiliation(s)
- Fathia Djelti
- 1 INSERM U1169 Le Kremlin-Bicêtre and Université Paris-Sud, 91400 Orsay, France
| | - Jerome Braudeau
- 1 INSERM U1169 Le Kremlin-Bicêtre and Université Paris-Sud, 91400 Orsay, France
| | - Eloise Hudry
- 1 INSERM U1169 Le Kremlin-Bicêtre and Université Paris-Sud, 91400 Orsay, France
| | - Marc Dhenain
- 2 CNRS URA2210 MIRCen CEA Fontenay aux Roses 92265, and Université Paris-Sud, 91400 Orsay, France
| | - Jennifer Varin
- 3 EA7331, Université Paris Descartes Sorbonne Paris Cité, Faculté des Sciences Pharmaceutiques et Biologiques, 75006 Paris, France
| | - Ivan Bièche
- 3 EA7331, Université Paris Descartes Sorbonne Paris Cité, Faculté des Sciences Pharmaceutiques et Biologiques, 75006 Paris, France
| | - Catherine Marquer
- 4 UMR S1127, and INSERM U1127, and CNRS UMR7225, and ICM, Sorbonne Université, UPMC Univ Paris 06 75013, Paris, France
| | - Farah Chali
- 4 UMR S1127, and INSERM U1127, and CNRS UMR7225, and ICM, Sorbonne Université, UPMC Univ Paris 06 75013, Paris, France
| | - Sophie Ayciriex
- 5 Chimie-Toxicologie Analytique et Cellulaire, EA 4463, Université Paris Descartes, Sorbonne Paris Cité, Faculté des Sciences Pharmaceutiques et Biologiques, 75006 Paris, France
| | - Nicolas Auzeil
- 5 Chimie-Toxicologie Analytique et Cellulaire, EA 4463, Université Paris Descartes, Sorbonne Paris Cité, Faculté des Sciences Pharmaceutiques et Biologiques, 75006 Paris, France
| | - Sandro Alves
- 1 INSERM U1169 Le Kremlin-Bicêtre and Université Paris-Sud, 91400 Orsay, France
| | - Dominique Langui
- 4 UMR S1127, and INSERM U1127, and CNRS UMR7225, and ICM, Sorbonne Université, UPMC Univ Paris 06 75013, Paris, France
| | - Marie-Claude Potier
- 4 UMR S1127, and INSERM U1127, and CNRS UMR7225, and ICM, Sorbonne Université, UPMC Univ Paris 06 75013, Paris, France
| | - Olivier Laprevote
- 5 Chimie-Toxicologie Analytique et Cellulaire, EA 4463, Université Paris Descartes, Sorbonne Paris Cité, Faculté des Sciences Pharmaceutiques et Biologiques, 75006 Paris, France
| | - Michel Vidaud
- 3 EA7331, Université Paris Descartes Sorbonne Paris Cité, Faculté des Sciences Pharmaceutiques et Biologiques, 75006 Paris, France
| | - Charles Duyckaerts
- 4 UMR S1127, and INSERM U1127, and CNRS UMR7225, and ICM, Sorbonne Université, UPMC Univ Paris 06 75013, Paris, France
| | - Richard Miles
- 4 UMR S1127, and INSERM U1127, and CNRS UMR7225, and ICM, Sorbonne Université, UPMC Univ Paris 06 75013, Paris, France
| | - Patrick Aubourg
- 1 INSERM U1169 Le Kremlin-Bicêtre and Université Paris-Sud, 91400 Orsay, France
| | - Nathalie Cartier
- 1 INSERM U1169 Le Kremlin-Bicêtre and Université Paris-Sud, 91400 Orsay, France
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13
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Systematic dissection of coding exons at single nucleotide resolution supports an additional role in cell-specific transcriptional regulation. PLoS Genet 2014; 10:e1004592. [PMID: 25340400 PMCID: PMC4207465 DOI: 10.1371/journal.pgen.1004592] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 07/09/2014] [Indexed: 12/22/2022] Open
Abstract
In addition to their protein coding function, exons can also serve as transcriptional enhancers. Mutations in these exonic-enhancers (eExons) could alter both protein function and transcription. However, the functional consequence of eExon mutations is not well known. Here, using massively parallel reporter assays, we dissect the enhancer activity of three liver eExons (SORL1 exon 17, TRAF3IP2 exon 2, PPARG exon 6) at single nucleotide resolution in the mouse liver. We find that both synonymous and non-synonymous mutations have similar effects on enhancer activity and many of the deleterious mutation clusters overlap known liver-associated transcription factor binding sites. Carrying a similar massively parallel reporter assay in HeLa cells with these three eExons found differences in their mutation profiles compared to the liver, suggesting that enhancers could have distinct operating profiles in different tissues. Our results demonstrate that eExon mutations could lead to multiple phenotypes by disrupting both the protein sequence and enhancer activity and that enhancers can have distinct mutation profiles in different cell types. Exons that code for protein can also have additional functions, such as regulating gene transcription through enhancer activity. Here, we changed every nucleotide in three different exons that also function as enhancers, and examined their enhancer activity to test whether nucleotide changes in these exons can affect both the protein sequence and enhancer function. We found that mutations with a significant effect on enhancer function can reside both in regions that change the protein sequence (non-synonymous) and regions that do not change it (synonymous). When we conducted a similar analysis in a different cell type, we observed a difference in the nucleotide changes that cause a significant effect on enhancer activity, suggesting that the enhancer functional units can differ between tissues.
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14
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Tassew NG, Mothe AJ, Shabanzadeh AP, Banerjee P, Koeberle PD, Bremner R, Tator CH, Monnier PP. Modifying lipid rafts promotes regeneration and functional recovery. Cell Rep 2014; 8:1146-59. [PMID: 25127134 DOI: 10.1016/j.celrep.2014.06.014] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Revised: 04/17/2014] [Accepted: 06/10/2014] [Indexed: 10/24/2022] Open
Abstract
Ideal strategies to ameliorate CNS damage should promote both neuronal survival and axon regeneration. The receptor Neogenin promotes neuronal apoptosis. Its ligand prevents death, but the resulting repulsive guidance molecule a (RGMa)-Neogenin interaction also inhibits axonal growth, countering any prosurvival benefits. Here, we explore strategies to inhibit Neogenin, thus simultaneously enhancing survival and regeneration. We show that bone morphogenetic protein (BMP) and RGMa-dependent recruitment of Neogenin into lipid rafts requires an interaction between RGMa and Neogenin subdomains. RGMa or Neogenin peptides that prevent this interaction, BMP inhibition by Noggin, or reduction of membrane cholesterol all block Neogenin raft localization, promote axon outgrowth, and prevent neuronal apoptosis. Blocking Neogenin raft association influences axonal pathfinding, enhances survival in the developing CNS, and promotes survival and regeneration in the injured adult optic nerve and spinal cord. Moreover, lowering cholesterol disrupts rafts and restores locomotor function after spinal cord injury. These data reveal a unified strategy to promote both survival and regeneration in the CNS.
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Affiliation(s)
- Nardos G Tassew
- Toronto Western Research Institute, Genetics and Development Division, Krembil Discovery Tower, KDT-8-418, 60 Leonard Street, Toronto, ON M5T 2S8, Canada; Department of Physiology, Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
| | - Andrea J Mothe
- Toronto Western Research Institute, Genetics and Development Division, Krembil Discovery Tower, KDT-8-418, 60 Leonard Street, Toronto, ON M5T 2S8, Canada
| | - Alireza P Shabanzadeh
- Toronto Western Research Institute, Genetics and Development Division, Krembil Discovery Tower, KDT-8-418, 60 Leonard Street, Toronto, ON M5T 2S8, Canada; Department of Anatomy, Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
| | - Paromita Banerjee
- Toronto Western Research Institute, Genetics and Development Division, Krembil Discovery Tower, KDT-8-418, 60 Leonard Street, Toronto, ON M5T 2S8, Canada
| | - Paulo D Koeberle
- Department of Anatomy, Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada; Department of Ophthalmology, Faculty of Medicine, 340 College Street, University of Toronto, Toronto, ON M5T 3A9, Canada
| | - Rod Bremner
- Toronto Western Research Institute, Genetics and Development Division, Krembil Discovery Tower, KDT-8-418, 60 Leonard Street, Toronto, ON M5T 2S8, Canada; Department of Ophthalmology, Faculty of Medicine, 340 College Street, University of Toronto, Toronto, ON M5T 3A9, Canada; Samuel Lunenfeld Research Institute, Mount Sinai Hospital, 982 University Avenue, Toronto, ON M5G 1X5, Canada
| | - Charles H Tator
- Toronto Western Research Institute, Genetics and Development Division, Krembil Discovery Tower, KDT-8-418, 60 Leonard Street, Toronto, ON M5T 2S8, Canada
| | - Philippe P Monnier
- Toronto Western Research Institute, Genetics and Development Division, Krembil Discovery Tower, KDT-8-418, 60 Leonard Street, Toronto, ON M5T 2S8, Canada; Department of Physiology, Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada; Department of Ophthalmology, Faculty of Medicine, 340 College Street, University of Toronto, Toronto, ON M5T 3A9, Canada.
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15
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Spagnuolo MS, Maresca B, Mollica MP, Cavaliere G, Cefaliello C, Trinchese G, Esposito MG, Scudiero R, Crispino M, Abrescia P, Cigliano L. Haptoglobin increases with age in rat hippocampus and modulates Apolipoprotein E mediated cholesterol trafficking in neuroblastoma cell lines. Front Cell Neurosci 2014; 8:212. [PMID: 25140128 PMCID: PMC4122225 DOI: 10.3389/fncel.2014.00212] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 07/15/2014] [Indexed: 01/07/2023] Open
Abstract
Alteration in cholesterol metabolism has been implicated in the pathogenesis of several neurodegenerative disorders. Apolipoprotein E (ApoE) is the major component of brain lipoproteins supporting cholesterol transport. We previously reported that the acute-phase protein Haptoglobin (Hpt) binds ApoE, and influences its function in blood cholesterol homeostasis. Major aim of this study was to investigate whether Hpt influences the mechanisms by which cholesterol is shuttled from astrocytes to neurons. In detail it was studied Hpt effect on ApoE-dependent cholesterol efflux from astrocytes and ApoE-mediated cholesterol incorporation in neurons. We report here that Hpt impairs ApoE-mediated cholesterol uptake in human neuroblastoma cell line SH-SY5Y, and limits the toxicity of a massive concentration of cholesterol for these cells, while it does not affect cholesterol efflux from the human glioblastoma-astrocytoma cell line U-87 MG. As aging is the most important non-genetic risk factor for various neurodegenerative disorders, and our results suggest that Hpt modulates ApoE functions, we evaluated the Hpt and ApoE expression profiles in cerebral cortex and hippocampus of adolescent (2 months), adult (5 and 8 months), and middle-aged (16 months) rats. Hpt mRNA level was higher in hippocampus of 8 and 16 month-old than in 2-month old rats (p < 0.05), and Hpt concentration increased with the age from adolescence to middle-age (p < 0.001). ApoE concentration, in hippocampus, was higher (p < 0.001) in 5 month-old rats compared to 2 month but did not further change with aging. No age-related changes of Hpt (protein and mRNA) were found in the cortex. Our results suggest that aging is associated with changes, particularly in the hippocampus, in the Hpt/ApoE ratio. Age-related changes in the concentration of Hpt were also found in human cerebrospinal fluids. The age-related changes might affect neuronal function and survival in brain, and have important implications in brain pathophysiology.
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Affiliation(s)
- Maria Stefania Spagnuolo
- Department of Bio-Agrofood Science, Institute of Animal Production Systems in Mediterranean Environments, National Research Council Naples, Italy
| | | | | | - Gina Cavaliere
- Department of Biology, University of Naples Federico II Naples, Italy
| | | | | | | | - Rosaria Scudiero
- Department of Biology, University of Naples Federico II Naples, Italy
| | - Marianna Crispino
- Department of Biology, University of Naples Federico II Naples, Italy
| | - Paolo Abrescia
- Department of Biology, University of Naples Federico II Naples, Italy
| | - Luisa Cigliano
- Department of Biology, University of Naples Federico II Naples, Italy
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16
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Peng H, Wang C, Chen Z, Sun Z, Jiao B, Li K, Huang F, Hou X, Wang J, Shen L, Xia K, Tang B, Jiang H. APOE ε2 allele may decrease the age at onset in patients with spinocerebellar ataxia type 3 or Machado-Joseph disease from the Chinese Han population. Neurobiol Aging 2014; 35:2179.e15-8. [PMID: 24746364 DOI: 10.1016/j.neurobiolaging.2014.03.020] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Revised: 02/16/2014] [Accepted: 03/14/2014] [Indexed: 02/06/2023]
Abstract
Polymorphism of the apolipoprotein E (APOE) gene has been defined as a modifying factor for age at onset (AO) in neurodegenerative disorders. The AO of spinocerebellar ataxia type 3 or Machado-Joseph disease (SCA3 or MJD) is inversely correlated with expanded CAG repeat lengths in the ATXN3 gene; however, AO is only partially explained by the expanded CAG repeats. We performed a case-control study to explore whether APOE genotypes play a role in AO of SCA3 or MJD from the Chinese Han population. The APOE genotypes were analyzed in an independent cohort of 155 patients with SCA3 or MJD and 191 controls both from Mainland China. Our study demonstrated that SCA3 or MJD patients experienced an earlier onset if they were carriers of APOE ε2 allele, which decreased the AO by nearly 4 years. This study may also reconfirm the effect of the APOE gene on SCA3 or MJD patients from different races and indicated that certain APOE alleles might be genetic modifiers for AO in SCA3 or MJD.
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Affiliation(s)
- Huirong Peng
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, P. R. China
| | - Chunrong Wang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, P. R. China
| | - Zhao Chen
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, P. R. China
| | - Zhanfang Sun
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, P. R. China
| | - Bin Jiao
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, P. R. China
| | - Kai Li
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, P. R. China
| | - Fengzhen Huang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, P. R. China
| | - Xuan Hou
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, P. R. China
| | - Junling Wang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, P. R. China; Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, P. R. China
| | - Lu Shen
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, P. R. China; Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, P. R. China; State Key Lab of Medical Genetics, Central South University, Changsha, Hunan, P. R. China
| | - Kun Xia
- State Key Lab of Medical Genetics, Central South University, Changsha, Hunan, P. R. China
| | - Beisha Tang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, P. R. China; Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, P. R. China; State Key Lab of Medical Genetics, Central South University, Changsha, Hunan, P. R. China
| | - Hong Jiang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, P. R. China; Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, P. R. China; State Key Lab of Medical Genetics, Central South University, Changsha, Hunan, P. R. China.
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17
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Jasmin SB, Pearson V, Lalonde D, Domenger D, Théroux L, Poirier J. Differential regulation of ABCA1 and ABCG1 gene expressions in the remodeling mouse hippocampus after entorhinal cortex lesion and liver-X receptor agonist treatment. Brain Res 2014; 1562:39-51. [PMID: 24661912 DOI: 10.1016/j.brainres.2014.03.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2014] [Revised: 03/14/2014] [Accepted: 03/15/2014] [Indexed: 12/30/2022]
Abstract
Entorhinal cortex lesioning (ECL) causes an extensive deafferentation of the hippocampus that is classically followed by a compensatory reinnervation, where apolipoprotein E, the main extracellular lipid-carrier in the CNS, has been shown to play a crucial role by shuttling cholesterol to reconstructing neurons terminals. Hence, we investigated whether the ATP-binding cassette (ABC) transporters -A1 and -G1, known to regulate cellular cholesterol efflux and lipidation of the apolipoprotein E-containing lipoprotein complex are actively involved in this context of brain׳s plastic response to neurodegeneration and deafferentation. We assessed ABCA1 and ABCG1 mRNA and protein levels throughout the degenerative phase and the reinnervation process and evaluated the associated cholinergic sprouting following ECL in the adult mouse brain. We subsequently tested the effect of the pharmacological activation of the nuclear receptor LXR, prior to versus after ECL, on hippocampal ABCA1 and G1 expression and on reinnervation. ECL induced a time-dependent up-regulation of ABCA1, but not G1, that coincided with a significant increase in acetylcholine esterase (AChE) activity in the ipsilateral hippocampus. Pre-ECL, but not post-ECL i.p. treatment with the LXR agonist TO901317 also led to a significant increase solely in hippocampal ABCA1 expression, paralleled by increases in both AchE and synaptophysin protein levels in the deafferented hippocampus. Thus, ABCA1 and -G1 are differentially regulated in the lesioned brain and upon treatment with an LXR agonist. Further, TO901317-induced up-regulation of ABCA1 appears to be more beneficial in a prevention (pre-lesion) than rescue (post-lesion) treatment; both findings support a central role for ABC transporters in brain plasticity.
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Affiliation(s)
- Stéphanie Bélanger Jasmin
- Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada H4A 2B4; Douglas Mental Health University Institute, 6875 LaSalle Blvd, Verdun, Quebec, Canada H4H 1R3
| | - Vanessa Pearson
- Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada H4A 2B4; Douglas Mental Health University Institute, 6875 LaSalle Blvd, Verdun, Quebec, Canada H4H 1R3
| | - Daphnée Lalonde
- Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada H4A 2B4; Douglas Mental Health University Institute, 6875 LaSalle Blvd, Verdun, Quebec, Canada H4H 1R3
| | - Dorothée Domenger
- Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada H4A 2B4; Douglas Mental Health University Institute, 6875 LaSalle Blvd, Verdun, Quebec, Canada H4H 1R3
| | - Louise Théroux
- Douglas Mental Health University Institute, 6875 LaSalle Blvd, Verdun, Quebec, Canada H4H 1R3
| | - Judes Poirier
- Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada H4A 2B4; Douglas Mental Health University Institute, 6875 LaSalle Blvd, Verdun, Quebec, Canada H4H 1R3.
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18
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Sonnino S, Aureli M, Grassi S, Mauri L, Prioni S, Prinetti A. Lipid Rafts in Neurodegeneration and Neuroprotection. Mol Neurobiol 2013; 50:130-48. [DOI: 10.1007/s12035-013-8614-4] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Accepted: 12/08/2013] [Indexed: 11/28/2022]
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19
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Lewis TL, Courchet J, Polleux F. Cell biology in neuroscience: Cellular and molecular mechanisms underlying axon formation, growth, and branching. ACTA ACUST UNITED AC 2013; 202:837-48. [PMID: 24043699 PMCID: PMC3776347 DOI: 10.1083/jcb.201305098] [Citation(s) in RCA: 114] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Proper brain wiring during development is pivotal for adult brain function. Neurons display a high degree of polarization both morphologically and functionally, and this polarization requires the segregation of mRNA, proteins, and lipids into the axonal or somatodendritic domains. Recent discoveries have provided insight into many aspects of the cell biology of axonal development including axon specification during neuronal polarization, axon growth, and terminal axon branching during synaptogenesis.
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Affiliation(s)
- Tommy L Lewis
- The Scripps Research Institute, Dorris Neuroscience Center, Department of Molecular and Cellular Neuroscience, La Jolla, CA 92037
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20
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Abstract
Amyotrophic lateral sclerosis is a fatal neurodegenerative disease. Epidemiologic data suggest that malnutrition is a common feature in amyotrophic lateral sclerosis and being overweight or obese confers a survival advantage in this patient population. In amyotrophic lateral sclerosis mouse models, a high-fat diet has been shown to lead to weight gain and prolonged survival. However, little research has been conducted to test whether nutritional interventions might ameliorate the disease course in humans. Here we review the currently available evidence supporting the potential role of dietary interventions as a therapeutic tool for amyotrophic lateral sclerosis. Ultimately, determining whether a high-fat or ketogenic diet could be beneficial in amyotrophic lateral sclerosis will require large randomized, placebo-controlled clinical trials.
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Affiliation(s)
- Sabrina Paganoni
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA,Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital and Harvard Medical School, Boston, MA, USA
| | - Anne-Marie Wills
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
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21
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Hung YH, Bush AI, La Fontaine S. Links between copper and cholesterol in Alzheimer's disease. Front Physiol 2013; 4:111. [PMID: 23720634 PMCID: PMC3655288 DOI: 10.3389/fphys.2013.00111] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 04/30/2013] [Indexed: 01/01/2023] Open
Abstract
Altered copper homeostasis and hypercholesterolemia have been identified independently as risk factors for Alzheimer's disease (AD). Abnormal copper and cholesterol metabolism are implicated in the genesis of amyloid plaques and neurofibrillary tangles (NFT), which are two key pathological signatures of AD. Amyloidogenic processing of a sub-population of amyloid precursor protein (APP) that produces Aβ occurs in cholesterol-rich lipid rafts in copper deficient AD brains. Co-localization of Aβ and a paradoxical high concentration of copper in lipid rafts fosters the formation of neurotoxic Aβ:copper complexes. These complexes can catalytically oxidize cholesterol to generate H2O2, oxysterols and other lipid peroxidation products that accumulate in brains of AD cases and transgenic mouse models. Tau, the core protein component of NFTs, is sensitive to interactions with copper and cholesterol, which trigger a cascade of hyperphosphorylation and aggregation preceding the generation of NFTs. Here we present an overview of copper and cholesterol metabolism in the brain, and how their integrated failure contributes to development of AD.
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Affiliation(s)
- Ya Hui Hung
- Oxidation Biology Laboratory, Florey Institute of Neuroscience and Mental Health Parkville, VIC, Australia ; Centre for Neuroscience Research, The University of Melbourne Parkville, VIC, Australia
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22
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Sortilin and SorLA regulate neuronal sorting of trophic and dementia-linked proteins. Mol Neurobiol 2012; 45:379-87. [PMID: 22297619 DOI: 10.1007/s12035-012-8236-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Accepted: 01/12/2012] [Indexed: 12/24/2022]
Abstract
Sortilin and SorLA are members of the Vps10p domain receptor family, the Sortilins, which comprise five type I transmembrane receptors differentially expressed in neuronal tissues of the central and peripheral nervous system. Since the identification of sortilin in 1997, members of this receptor family are recognized as sorting receptors primarily in the trans-Golgi network, interacting with a wide range of ligands comprising other transmembrane receptors as well as soluble proteins from neurotrophic factors to enzymes targeted for lysosomes. Specifically, the involvement of sortilin in neutrophin signaling in healthy and injured neurons is increasingly recognized, as well as the impact of SorLA on the cellular processing of amyloid precursor protein, an important component in Alzheimer's disease. The current understanding of these issues as well as the recent recognition of a molecular link between sortilin and frontotemporal dementia is addressed in this present review.
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23
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Dietary β-carotene regulates interleukin-1β-induced expression of apolipoprotein E in astrocytes isolated from stroke-prone spontaneously hypertensive rats. Neurochem Int 2012; 62:43-9. [PMID: 23147682 DOI: 10.1016/j.neuint.2012.11.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Revised: 10/29/2012] [Accepted: 11/01/2012] [Indexed: 12/31/2022]
Abstract
Stroke-prone spontaneously hypertensive rats (SHRSP) have an abnormality in cholesterol synthesis, but the pathological relevance of this to stroke and related neuronal disorders is not yet clear. The induction of astrocyte-derived cholesterol transportation to neurons by apolipoprotein E (apoE) promotes neuronal repair after brain injuries such as stroke. Such repair is reduced by interleukin-1 beta (IL-1β) and stroke conditions. Furthermore, fibroblast growth factor 1 (FGF1) regulates the production of apoE-cholesterol-rich high density lipoproteins (HDL) and induces gliosis of astrocytes. On the other hand, high levels of plasma carotenoids reduce the risk of ischemic stroke. Thus, we investigated the expression of apoE in primary astrocytes that had been treated with IL-1β or β-carotene. In addition, we compared the expression levels of Apoe genes in astrocytes from SHRSP/Izm and normal control rats, Wistar-Kyoto rats (WKY/Izm) following hypoxia/reoxygenation (H/R). The expression levels of genes and proteins were investigated by RT-PCR, Western blotting (WB), and immunofluorescence analysis. IL-1β decreased the expression levels of the Apoe gene. Conversely, β-carotene significantly enhanced the expression levels of genes related to cholesterol regulation, including Abca1, Abcg1, Hmgcr as well as Apoe. During H/R, the gene expression levels of Apoe were decreased in the SHRSP/Izm rats in comparison with the WKY/Izm rats. These results suggest that IL-1β decreases Apoe expression levels, whereas β-carotene strongly elevates Apoe levels and inhibits FGF1-mediated gliosis of astrocytes. Furthermore, under hypoxic stress, astrocytes isolated from SHRSP/Izm rats displayed altered regulation of Apoe compared with those from WKY/Izm rats.
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24
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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.
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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.
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25
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Posse de Chaves E. Reciprocal regulation of cholesterol and beta amyloid at the subcellular level in Alzheimer's disease. Can J Physiol Pharmacol 2012; 90:753-64. [PMID: 22626060 DOI: 10.1139/y2012-076] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Since the discovery that apolipoprotein E, a cholesterol transport protein, is a major risk factor for Alzheimer's disease (AD) development, there has been a remarkable interest in understanding the many facets of the relationship between cholesterol and AD. Several lines of evidence have demonstrated the importance of cholesterol in amyloid beta peptide (Aβ) production and metabolism, as well as the involvement of Aβ in cholesterol homeostasis. The emerging picture is complex and still incomplete. This review discusses findings that indicate that a reciprocal regulation exists between Aβ and cholesterol at the subcellular level. The pathological impact of such regulation is highlighted.
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Affiliation(s)
- Elena Posse de Chaves
- Department of Pharmacology, 9-31 Medical Sciences Building, University of Alberta, Edmonton, AB T6G 2H7, Canada.
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26
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Abstract
Neurotrophic factors released by target tissues maintain the survival and differentiation of innervating neurons. The manner by which these target-derived neurotrophic proteins communicate with innervating neurons has been actively pursued for over three decades. The present chapter describes a technique for preparing and maintaining compartmented chambers for culturing neurons derived from either superior cervical ganglia (sympathetic neurons) or dorsal root ganglia (sensory neurons). This system recapitulates the selective stimulation of neuron terminals that occurs in vivo following release of target-derived neurotrophins.
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Affiliation(s)
- Stephen D Skaper
- Department of Pharmacology and Anesthesiology, University of Padova, Padova, Italy.
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27
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Hayashi H. Lipid metabolism and glial lipoproteins in the central nervous system. Biol Pharm Bull 2011; 34:453-61. [PMID: 21467629 DOI: 10.1248/bpb.34.453] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Lipoproteins in the central nervous system (CNS) are not incorporated from the blood but are formed mainly by glial cells within the CNS. In addition, cholesterol in the CNS is synthesized endogenously because the blood-brain barrier segregates the CNS from the peripheral circulation. Apolipoprotein (apo) E is a major apo in the CNS. In normal condition, apo E is secreted from glia, mainly from astrocytes, and forms cholesterol-rich lipoproteins by ATP-binding cassette transporters. Subsequently, apo E-containing glial lipoproteins supply cholesterol and other components to neurons via a receptor-mediated process. Recent findings demonstrated that receptors of the low density lipoprotein (LDL) receptor family not only internalize lipoproteins into the cells but also, like signaling receptors, transduce signals upon binding the ligands. In this review, the regulation of lipid homeostasis will be discussed as well as roles of lipoproteins and functions of receptors of LDL receptor family in the CNS. Furthermore, the relation between lipid metabolism and Alzheimer's disease (AD) is discussed.
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Affiliation(s)
- Hideki Hayashi
- Priority Organization for Innovation and Excellence, Kumamoto University, Honjo, Japan.
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Unesterified cholesterol accumulation in late endosomes/lysosomes causes neurodegeneration and is prevented by driving cholesterol export from this compartment. J Neurosci 2011; 31:9404-13. [PMID: 21697390 DOI: 10.1523/jneurosci.1317-11.2011] [Citation(s) in RCA: 120] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
While unesterified cholesterol (C) is essential for remodeling neuronal plasma membranes, its role in certain neurodegenerative disorders remains poorly defined. Uptake of sterol from pericellular fluid requires processing that involves two lysosomal proteins, lysosomal acid lipase, which hydrolyzes C esters, and NPC1 (Niemann-Pick type C1). In systemic tissues, inactivation of either protein led to sterol accumulation and cell death, but in the brain, inactivation of only NPC1 caused C sequestration and neurodegeneration. When injected into the CNS of the npc1(-/-) mouse, 2-hydroxypropyl-β-cyclodextrin (HP-β-CD), a compound known to prevent this C accumulation, diffused throughout the brain and was excreted with a t(½) of 6.5 h. This agent caused suppression of C synthesis, elevation of C esters, suppression of sterol regulatory-binding protein 2 (SREBP2) target genes, and activation of liver X receptor-controlled genes. These findings indicated that HP-β-CD promoted movement of the sequestered C from lysosomes to the metabolically active pool of C in the cytosolic compartment of cells in the CNS. The ED(50) for this agent in the brain was ∼0.5 mg/kg, and the therapeutic effect lasted >7 d. Continuous infusion of HP-β-CD into the ventricular system of npc1(-/-) animals between 3 and 7 weeks of age normalized the biochemical abnormalities and completely prevented the expected neurodegeneration. These studies support the concept that neurons continuously acquire C from interstitial fluid to permit plasma membrane turnover and remodeling. Inactivation of NPC1 leads to lysosomal C sequestration and neurodegeneration, but this is prevented by the continuous, direct administration of HP-β-CD into the CNS.
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29
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The ATP-binding cassette transporter-2 (ABCA2) regulates cholesterol homeostasis and low-density lipoprotein receptor metabolism in N2a neuroblastoma cells. Biochim Biophys Acta Mol Cell Biol Lipids 2011; 1811:1152-64. [PMID: 21810484 DOI: 10.1016/j.bbalip.2011.07.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Revised: 07/12/2011] [Accepted: 07/14/2011] [Indexed: 11/23/2022]
Abstract
The ATP-binding cassette transporter-2 (ABCA2) has been identified as a possible regulator of lipid metabolism. ABCA2 is most highly expressed in the brain but its effects on cholesterol homeostasis in neuronal-type cells have not been characterized. It is important to study the role of ABCA2 in regulating cholesterol homeostasis in neuronal-type cells because ABCA2 has been identified as a possible genetic risk factor for Alzheimer's disease. In this study, the effects of ABCA2 expression on cholesterol homeostasis were examined in mouse N2a neuroblastoma cells. ABCA2 reduced total, free- and esterified cholesterol levels as well as membrane cholesterol but did not perturb cholesterol distribution in organelle or lipid raft compartments. ABCA2 did not modulate de novo cholesterol biosynthesis from acetate. Cholesterol trafficking to the plasma membrane was not affected by ABCA2 but efflux to the physiological acceptor ApoE3 and mobilization of plasma membrane cholesterol to the endoplasmic reticulum for esterification were reduced by ABCA2. ABCA2 reduced esterification of serum and low-density lipoprotein-derived cholesterol but not 25-hydroxycholesterol. ABCA2 decreased low-density lipoprotein receptor (LDLR) mRNA and protein levels and increased its turnover rate. The surface expression of LDLR as well as the uptake of fluroresecent DiI-LDL was also reduced by ABCA2. Reduction of endogenous ABCA2 expression by RNAi treatment of N2a cells and rat primary cortical neurons produced the opposite effects of over-expression of ABCA2, increasing LDLR protein levels. This report identifies ABCA2 as a key regulator of cholesterol homeostasis and LDLR metabolism in neuronal cells.
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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: 321] [Impact Index Per Article: 24.7] [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.
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Affiliation(s)
- Frank W Pfrieger
- CNRS UPR 3212, University of Strasbourg, Institute of Cellular and Integrative Neurosciences (INCI), 67084 Strasbourg Cedex, France.
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31
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Uno Y, Piao W, Miyata K, Nishina K, Mizusawa H, Yokota T. High-density lipoprotein facilitates in vivo delivery of α-tocopherol-conjugated short-interfering RNA to the brain. Hum Gene Ther 2011; 22:711-9. [PMID: 21166521 DOI: 10.1089/hum.2010.083] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
We originally reported the use of vitamin E (α-tocopherol) as an in vivo vector of short-interfering RNA (siRNA) to the liver. Here, we apply our strategy to the brain. By combining high-density lipoprotein (HDL) as a second carrier with α-tocopherol-conjugated siRNA (Toc-siRNA) in the brain, we achieved dramatic improvement of siRNA delivery to neurons. After direct intracerebroventricular (ICV) infusion of Toc-siRNA/HDL for 7 days, extensive and specific knock-down of a target gene, β-site amyloid precursor protein cleaving enzyme 1 (BACE1), was observed in both mRNA and protein levels, especially in the cerebral cortex and hippocampus. This new delivery method achieved a much more prominent down-regulation effect than conventional silencing methods of the brain gene, i.e., ICV infusion of nonconjugated siRNA or oligonucleotides. With only 3 nmol Toc-siRNA with HDL, BACE1 mRNA in the parietal cortex could be reduced by ∼ 70%. We suppose that this dramatic improvement of siRNA delivery to the brain is due to the use of lipoprotein receptor-mediated endocytosis because the silencing efficiency was significantly increased by binding of Toc-siRNA to the lipoprotein, and in contrast, was clearly decreased in lipoprotein-receptor knockout mice. These results suggest exogenous siRNA could be used clinically for otherwise incurable neurological diseases.
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Affiliation(s)
- Yoshitaka Uno
- Department of Neurology and Neurological Science, Graduate School, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo 113-0034, Japan
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Leduc V, Jasmin-Bélanger S, Poirier J. APOE and cholesterol homeostasis in Alzheimer's disease. Trends Mol Med 2011; 16:469-77. [PMID: 20817608 DOI: 10.1016/j.molmed.2010.07.008] [Citation(s) in RCA: 109] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2010] [Revised: 06/29/2010] [Accepted: 07/29/2010] [Indexed: 01/25/2023]
Abstract
Converging evidence from clinical and pathological studies indicate the presence of important relationships between the ongoing deterioration of brain lipid homeostasis, vascular changes and the pathophysiology of sporadic Alzheimer's disease (AD). These associations include the recognition of cholesterol transporters apolipoprotein E (APOE), APOC1 and APOJ as major genetic risk factors for common AD and observations associating risk factors for cardiovascular disease such as high midlife plasma cholesterol, diabetes, stroke, obesity and hypertension to dementia. Moreover, recent clinical findings lend support to the notion that progressive deterioration of cholesterol homeostasis in AD is a central player in the disease pathophysiology and is, therefore, a potential therapeutic target for disease prevention.
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Affiliation(s)
- Valérie Leduc
- Douglas Mental Health University Institute, 6875 Lasalle, Montreal (Verdun), Quebec, H4H 1R3, Canada
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33
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Ramirez CM, Liu B, Aqul A, Taylor AM, Repa JJ, Turley SD, Dietschy JM. Quantitative role of LAL, NPC2, and NPC1 in lysosomal cholesterol processing defined by genetic and pharmacological manipulations. J Lipid Res 2011; 52:688-98. [PMID: 21289032 DOI: 10.1194/jlr.m013789] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Lipoprotein cholesterol taken up by cells is processed in the endosomal/lysosomal (E/L) compartment by the sequential action of lysosomal acid lipase (LAL), Niemann-Pick C2 (NPC2), and Niemann-Pick C1 (NPC1). Inactivation of NPC2 in mouse caused sequestration of unesterified cholesterol (UC) and expanded the whole animal sterol pool from 2,305 to 4,337 mg/kg. However, this pool increased to 5,408 and 9,480 mg/kg, respectively, when NPC1 or LAL function was absent. The transport defect in mutants lacking NPC2 or NPC1, but not in those lacking LAL, was reversed by cyclodextrin (CD), and the ED₅₀ values for this reversal varied from ~40 mg/kg in kidney to >20,000 mg/kg in brain in both groups. This reversal occurred only with a CD that could interact with UC. Further, a CD that could interact with, but not solubilize, UC still overcame the transport defect. These studies showed that processing and export of sterol from the late E/L compartment was quantitatively different in mice lacking LAL, NPC2, or NPC1 function. In both npc2(-/-) and npc1(-/-) mice, the transport defect was reversed by a CD that interacted with UC, likely at the membrane/bulk-water interface, allowing sterol to move rapidly to the export site of the E/L compartment.
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Affiliation(s)
- Charina M Ramirez
- Department of Pediatrics, University of Texas Southwestern Medical School, Dallas, TX 75390-9151, USA
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Matsuo M, Campenot RB, Vance DE, Ueda K, Vance JE. Involvement of low-density lipoprotein receptor-related protein and ABCG1 in stimulation of axonal extension by apoE-containing lipoproteins. Biochim Biophys Acta Mol Cell Biol Lipids 2010; 1811:31-8. [PMID: 21040802 DOI: 10.1016/j.bbalip.2010.10.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Revised: 10/19/2010] [Accepted: 10/24/2010] [Indexed: 10/18/2022]
Abstract
Apolipoprotein E (apoE)-containing lipoproteins (LpE) are produced by glial cells in the central nervous system (CNS). When LpE are supplied to distal axons, but not cell bodies, of CNS neurons (retinal ganglion cells) the rate of axonal extension is increased. In this study we have investigated the molecular requirements underlying the stimulatory effect of LpE on axonal extension. We show that enhancement of axonal growth by LpE requires the presence of the low-density lipoprotein receptor-related protein-1 (LRP1) in neurons since RNA silencing of LRP1 in neurons, or antibodies directed against LRP, suppressed the LpE-induced axonal extension. In contrast, an alternative LRP1 ligand, α2-macroglobulin, failed to stimulate axonal extension, suggesting that LpE do not exert their growth-stimulatory effect solely by activation of a LRP1-mediated signaling pathway. In addition, although apoE3-containing LpE enhanced axonal extension, apoE4-containing LpE did not. Over-expression of ABCG1 in rat cortical glial cells resulted in production of LpE that increased the rate of axonal extension to a greater extent than did expression of an inactive, mutant form of ABGC1. Furthermore, reconstituted lipoprotein particles containing apoE3, phosphatidylcholine and sphingomyelin, but not cholesterol, stimulated axonal extension, suggesting that sphingomyelin, but not cholesterol, is involved in the stimulatory effect of LpE. These observations demonstrate that LpE and LRP1 promote axonal extension, and suggest that lipids exported to LpE by ABCG1 are important for the enhancement of axonal extension mediated by LpE.
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Affiliation(s)
- Michinori Matsuo
- Group on Molecular and Cell Biology of Lipids, University of Alberta, Edmonton, Alberta, Canada
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Ramirez CM, Liu B, Taylor AM, Repa JJ, Burns DK, Weinberg AG, Turley SD, Dietschy JM. Weekly cyclodextrin administration normalizes cholesterol metabolism in nearly every organ of the Niemann-Pick type C1 mouse and markedly prolongs life. Pediatr Res 2010; 68:309-15. [PMID: 20581737 PMCID: PMC3065173 DOI: 10.1203/pdr.0b013e3181ee4dd2] [Citation(s) in RCA: 136] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Niemann-Pick type C1 (NPC1) disease arises from a mutation inactivating NPC1 protein that normally moves unesterified cholesterol from the late endosomal/lysosomal complex of cells to the cytosolic compartment for processing. As a result, cholesterol accumulates in every tissue of the body causing liver, lung, and CNS disease. Treatment of the murine model of this disease, the npc1 mouse, s.c. with β-cyclodextrin (4000 mg/kg) one time each week normalized cellular cholesterol metabolism in the liver and most other organs. At the same time, the hepatic dysfunction seen in the untreated npc1 mouse was prevented. The severity of cerebellar neurodegeneration also was ameliorated, although not entirely prevented, and the median lifespan of the animals was doubled. However, in contrast to these other organs, lung showed progressive macrophage infiltration with development of lipoid pneumonitis. These studies demonstrated that weekly cyclodextrin administration overcomes the lysosomal transport defect associated with the NPC1 mutation, nearly normalizes hepatic and whole animal cholesterol pools, and prevents the development of liver disease. Furthermore, this treatment slows cerebellar neurodegeneration but has little or no effect on the development of progressive pulmonary disease.
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Affiliation(s)
- Charina M Ramirez
- Department of Pediatrics, University of Texas Southwestern Medical School at Dallas, Texas 75390, USA
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36
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Abstract
OBJECTIVE Cholesterol 24-hydroxylase catalyzes the conversion of cholesterol to 24-hydroxycholesterol, which is a major pathway for cholesterol elimination from the brain, since 24-hydroxycholesterol can readily cross the blood brain barrier. The present study aimed to elucidate the distribution of cholesterol 24-hydroxylase in the monkey brain. METHODS The distribution of cholesterol 24-hydroxylase in the monkey brain was examined using Western blot and immunohistochemistry methods, and was observed under light microscopy and electron microscopy. RESULTS High levels of cholesterol 24-hydroxylase were observed in projection neurons and neuropil in structures derived from telencephalon, including the cerebral neocortex, hippocampus, amygdala, nucleus basalis of Meynert, and striatum. Electron microscopy revealed that the enzyme was localized in the axon terminals. One the other hand, cholesterol 24-hydroxylase was expressed at a lower level in the thalamus, globus pallidus and brainstem. CONCLUSION The high level of cholesterol 24-hydroxylase in the telencephalon possibly reflects a high rate of cholesterol turnover in this part of brain.
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Hauser PS, Narayanaswami V, Ryan RO. Apolipoprotein E: from lipid transport to neurobiology. Prog Lipid Res 2010; 50:62-74. [PMID: 20854843 DOI: 10.1016/j.plipres.2010.09.001] [Citation(s) in RCA: 218] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Revised: 09/04/2010] [Accepted: 09/12/2010] [Indexed: 12/17/2022]
Abstract
Apolipoprotein (apo) E has a storied history as a lipid transport protein. The integral association between cholesterol homeostasis and lipoprotein clearance from circulation are intimately related to apoE's function as a ligand for cell-surface receptors of the low-density lipoprotein receptor family. The receptor binding properties of apoE are strongly influenced by isoform specific amino acid differences as well as the lipidation state of the protein. As understanding of apoE as a structural component of circulating plasma lipoproteins has evolved, exciting developments in neurobiology have revitalized interest in apoE. The strong and enduring correlation between the apoE4 isoform and age of onset and increased risk of Alzheimer's disease has catapulted apoE to the forefront of neurobiology. Using genetic tools generated for study of apoE lipoprotein metabolism, transgenic "knock-in" and gene-disrupted mice are now favored models for study of its role in a variety of neurodegenerative diseases. Key structural knowledge of apoE and isoform-specific differences is driving research activity designed to elucidate how a single amino acid change can manifest such profoundly significant pathological consequences. This review describes apoE through a lens of structure-based knowledge that leads to hypotheses that attempt to explain the functions of apoE and isoform-specific effects relating to disease mechanism.
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Affiliation(s)
- Paul S Hauser
- Center for Prevention of Obesity, Cardiovascular Disease and Diabetes, Children's Hospital Oakland Research Institute, 5700 Martin Luther King Jr. Way, Oakland, CA 94609, USA
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38
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Oxidized low-density lipoprotein (oxLDL) induces cell death in neuroblastoma and survival autophagy in schwannoma cells. Exp Mol Pathol 2010; 89:276-83. [PMID: 20692253 DOI: 10.1016/j.yexmp.2010.07.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2010] [Revised: 07/19/2010] [Accepted: 07/30/2010] [Indexed: 11/24/2022]
Abstract
Oxidized low-density lipoprotein (oxLDL) induces apoptosis or autophagy in dependence on the cell type. We here investigated the effect of oxLDL on the B104 neuroblastoma and RN22 schwannoma cells being popular in neuroscience research. Cells were cultivated with and without oxLDL. To generate oxLDL, we added 50 μg/ml nLDL and 50 μM CuSO(4) into the culture medium. After a 24-h-long treatment, oxLDL was detectable in media from both cell culture types and its concentration was approximately 16 μg/ml. In the oxLDL-treated B104 neuroblastoma cell cultures 75% cells died after the 24-h exposure. The intact cells showed impaired mitochondria at the ultrastructural level. Western blot analysis revealed the increased expression of AIF 57 kDa (AIF(57)) protein, as a sign of caspase-independent cell death. In RN22 schwannoma cell cultures, oxLDL did not have any effect on cleaved caspase-3 and AIF(57) protein levels indicating absence of cell death. Treated RN22 schwannoma cells underwent survival autophagy by forming conspicuous autophagosomes and by processing LC3-I into LC3-II protein. Collectively, oxLDL induces AIF-dependent cell death in B104 neuroblastoma cells whereas in RN22 schwannoma cells enhanced signs of survival autophagy are noted.
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Nowicki M, Müller K, Serke H, Kosacka J, Vilser C, Ricken A, Spanel-Borowski K. Oxidized low-density lipoprotein (oxLDL)-induced cell death in dorsal root gangion cell cultures depends not on the lectin-like oxLDL receptor-1 but on the toll-like receptor-4. J Neurosci Res 2010; 88:403-12. [DOI: 10.1002/jnr.22205] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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40
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Bartzokis G. Alzheimer's disease as homeostatic responses to age-related myelin breakdown. Neurobiol Aging 2009; 32:1341-71. [PMID: 19775776 DOI: 10.1016/j.neurobiolaging.2009.08.007] [Citation(s) in RCA: 382] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2008] [Revised: 08/13/2009] [Accepted: 08/17/2009] [Indexed: 12/11/2022]
Abstract
The amyloid hypothesis (AH) of Alzheimer's disease (AD) posits that the fundamental cause of AD is the accumulation of the peptide amyloid beta (Aβ) in the brain. This hypothesis has been supported by observations that genetic defects in amyloid precursor protein (APP) and presenilin increase Aβ production and cause familial AD (FAD). The AH is widely accepted but does not account for important phenomena including recent failures of clinical trials to impact dementia in humans even after successfully reducing Aβ deposits. Herein, the AH is viewed from the broader overarching perspective of the myelin model of the human brain that focuses on functioning brain circuits and encompasses white matter and myelin in addition to neurons and synapses. The model proposes that the recently evolved and extensive myelination of the human brain underlies both our unique abilities and susceptibility to highly prevalent age-related neuropsychiatric disorders such as late onset AD (LOAD). It regards oligodendrocytes and the myelin they produce as being both critical for circuit function and uniquely vulnerable to damage. This perspective reframes key observations such as axonal transport disruptions, formation of axonal swellings/sphenoids and neuritic plaques, and proteinaceous deposits such as Aβ and tau as by-products of homeostatic myelin repair processes. It delineates empirically testable mechanisms of action for genes underlying FAD and LOAD and provides "upstream" treatment targets. Such interventions could potentially treat multiple degenerative brain disorders by mitigating the effects of aging and associated changes in iron, cholesterol, and free radicals on oligodendrocytes and their myelin.
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Affiliation(s)
- George Bartzokis
- Department of Psychiatry and Biobehavioral Sciences, The David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA.
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41
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Expression of cholesterol homeostasis genes in the brain of the male rat is affected by age and dietary restriction. Biogerontology 2009; 10:735-45. [DOI: 10.1007/s10522-009-9220-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2008] [Accepted: 02/26/2009] [Indexed: 10/21/2022]
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Abstract
PURPOSE OF REVIEW Aberrations in cerebral cholesterol homeostasis can lead to severe neurological diseases and have been linked to Alzheimer's disease. Many proteins involved in peripheral cholesterol metabolism are also present in the brain. Yet, brain cholesterol metabolism is very different from that in the remainder of the body. This review reports on present insights into the regulation of cerebral cholesterol homeostasis, focusing on cholesterol trafficking between astrocytes and neurons. RECENT FINDINGS Astrocytes are a major site of cholesterol synthesis. They secrete cholesterol in the form of apolipoprotein E-containing HDL-like particles. After birth, neurons are thought to reduce their cholesterol synthesis and rely predominantly on astrocytes for their cholesterol supply. How exactly neurons regulate their cholesterol supply is largely unknown. A role for the brain-specific cholesterol metabolite, 24(S)-hydroxycholesterol, in this process was recently proposed. Recent findings strengthen the link between brain cholesterol metabolism and factors involved in synaptic plasticity, a process essential for learning and memory functions, as well as regeneration, which are affected in Alzheimer's disease. SUMMARY Insight into the regulation of cerebral cholesterol homeostasis will provide possibilities to modulate the key steps involved and may lead to the development of therapies for the prevention as well as treatment of neurodegenerative diseases such as Alzheimer's disease.
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Affiliation(s)
- Monique Mulder
- Department of Internal Medicine and Division of Pharmacology, Vascular and Metabolic diseases, Erasmus Medical Center, Rotterdam, The Netherlands.
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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.
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Affiliation(s)
- Barbara Karten
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada
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Doering JE, Kane K, Hsiao YC, Yao C, Shi B, Slowik AD, Dhagat B, Scott DD, Ault JG, Page-McCaw PS, Ferland RJ. Species differences in the expression of Ahi1, a protein implicated in the neurodevelopmental disorder Joubert syndrome, with preferential accumulation to stigmoid bodies. J Comp Neurol 2008; 511:238-56. [PMID: 18785627 DOI: 10.1002/cne.21824] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Joubert syndrome (JBTS) is an autosomal recessive disorder characterized by cerebellum and brainstem malformations. Individuals with JBTS have abnormal breathing and eye movements, ataxia, hypotonia, and cognitive difficulty, and they display mirror movements. Mutations in the Abelson-helper integration site-1 gene (AHI1) cause JBTS in humans, suggesting that AHI1 is required for hindbrain development; however AHI1 may also be required for neuronal function. Support for this idea comes from studies demonstrating that the AHI1 locus is associated with schizophrenia. To gain further insight into the function of AHI1 in both the developing and mature central nervous system, we determined the spatial and temporal expression patterns of the gene products of AHI1 orthologs throughout development, in human, mouse, and zebrafish. Murine Ahi1 was distributed throughout the cytoplasm, dendrites, and axons of neurons, but was absent in glial cells. Ahi1 expression in the mouse brain was observed as early as embryonic day 10.5 and persisted into adulthood, with peak expression during the first postnatal week. Murine Ahi1 was observed in neurons of the hindbrain, midbrain, and ventral forebrain. Generally, the AHI1/Ahi1/ahi1 orthologs had a conserved distribution pattern in human, mouse, and zebrafish, but mouse Ahi1 was not present in the developing and mature cerebellum. Ahi1 was also observed consistently in the stigmoid body, a poorly characterized cytoplasmic organelle found in neurons. Overall, these results suggest roles for AHI1 in neurodevelopmental processes that underlie most of the neuroanatomical defects in JBTS, and perhaps in neuronal functions that contribute to schizophrenia.
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Affiliation(s)
- Jennifer E Doering
- Department of Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180, USA
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de Chaves EP, Narayanaswami V. Apolipoprotein E and cholesterol in aging and disease in the brain. ACTA ACUST UNITED AC 2008; 3:505-530. [PMID: 19649144 DOI: 10.2217/17460875.3.5.505] [Citation(s) in RCA: 118] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Cholesterol can be detrimental or vital, and must be present in the right place at the right time and in the right amount. This is well known in the heart and the vascular system. However, in the CNS cholesterol is still an enigma, although several of its fundamental functions in the brain have been identified. Brain cholesterol has attracted additional attention owing to its close connection to ApoE, a key polymorphic transporter of extracellular cholesterol in humans. Indeed, both cholesterol and ApoE are so critical to fundamental activities of the brain, that the brain regulates their synthesis autonomously. Yet, similar control mechanisms of ApoE and cholesterol homeostasis may exist on either sides of the blood-brain barrier. One indication is that the APOE ε4 allele is associated with hypercholesterolemia and a proatherogenic profile on the vascular side and with increased risk of Alzheimer's disease on the CNS side. In this review, we draw attention to the association between cholesterol and ApoE in the aging and diseased brain, and to the behavior of the ApoE4 protein at the molecular level. The attempt to correlate in vivo and in vitro observations is challenging but crucial for developing future strategies to address ApoE-related aberrations in cholesterol metabolism selectively in the brain.
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Zhang J, Chen J, Li Y, Cui X, Zheng X, Roberts C, Lu M, Elias SB, Chopp M. Niaspan treatment improves neurological functional recovery in experimental autoimmune encephalomyelitis mice. Neurobiol Dis 2008; 32:273-80. [PMID: 18778774 DOI: 10.1016/j.nbd.2008.07.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2008] [Revised: 06/25/2008] [Accepted: 07/13/2008] [Indexed: 02/02/2023] Open
Abstract
We investigated the treatment of experimental autoimmune encephalomyelitis (EAE) in mice with Niaspan, an agent used to elevate high-density lipoprotein (HDL). EAE mice were treated with Niaspan starting on the immunization or clinical onset day. Neurological functional recovery was significantly increased in the Niaspan treated mice (100 mg/kgbw) compared to the controls. Inflammatory infiltrates were significantly reduced in the Niaspan treatment group compared to the EAE controls. HDL level, intact myelin area, newly formed oligodendrocytes, regenerating axons, gene and protein levels of sonic hedgehog (Shh)/Gli1 were significantly increased in the Niaspan treated mice compared to EAE controls. These data indicate that Niaspan treatment improved functional recovery after EAE, possibly, via reducing inflammatory infiltrates and demyelination areas, and stimulating oligodendrogenesis and axonal regeneration. Niaspan-mediated activation of Shh/Gli1 pathway may promote functional recovery post-EAE.
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Affiliation(s)
- Jing Zhang
- Department of Neurology, Henry Ford Health System, Detroit, MI 48202, USA
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Li Z, Vance DE. Thematic Review Series: Glycerolipids. Phosphatidylcholine and choline homeostasis. J Lipid Res 2008; 49:1187-94. [DOI: 10.1194/jlr.r700019-jlr200] [Citation(s) in RCA: 406] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Rickhag M, Deierborg T, Patel S, Ruscher K, Wieloch T. Apolipoprotein D is elevated in oligodendrocytes in the peri-infarct region after experimental stroke: influence of enriched environment. J Cereb Blood Flow Metab 2008; 28:551-62. [PMID: 17851453 DOI: 10.1038/sj.jcbfm.9600552] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Injury to the brain (e.g., stroke) results in a disruption of neuronal connectivity and loss of fundamental sensori-motor functions. The subsequent recovery of certain functions involves structural rearrangements in areas adjacent to the infarct. This remodeling of the injured brain requires trafficking of macromolecular components including cholesterol and phospholipids, a transport carried out by apolipoproteins including apolipoprotein D (apoD). We investigated the changes in the levels of apoD mRNA and protein, and its cellular localization during a recovery period up to 30 days after experimental stroke in the rat brain. In the core of the brain infarct, apoD immunoreactivity but not mRNA increased in dying pyramidal neurons, indicative of cellular redistribution of lipids. During 2 to 7 days of recovery after stroke, the apoD levels increased in the peri-infarct and white matter areas in cells identified as mature oligodendrocytes. The apoD expressing cells were conspicuously located along the rim of the infarct, suggesting a role for apoD in tissue repair. Furthermore, housing animals in an enriched environment improved sensori-motor function and increased the apoD levels. Our data strongly suggest that apoD is involved in regenerative processes and scar formation in the peri-infarct area presumably by enhancing lipid trafficking.
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Affiliation(s)
- Mattias Rickhag
- Laboratory for Experimental Brain Research, Wallenberg Neuroscience Center, University of Lund, Lund, Sweden.
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Bonneau S, Vever-Bizet C, Mojzisova H, Brault D. Tetrapyrrole-photosensitizers vectorization and plasma LDL: A physico-chemical approach. Int J Pharm 2007; 344:78-87. [PMID: 17656052 DOI: 10.1016/j.ijpharm.2007.06.019] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2007] [Revised: 06/01/2007] [Accepted: 06/06/2007] [Indexed: 11/16/2022]
Abstract
A photosensitizer is defined as a chemical entity able to induce, under light-irradiation effect, a chemical or physical alteration of another chemical entity. Thanks to their preferential retention in proliferating tissues, some photosensitizers are therapeutically used such as in photodynamic therapy (PDT). Besides, this method has already been approved for several indications. The selectivity of photosenzitizers for cells in proliferation involves both their association with low density lipoproteins (LDLs) and their ability to cross membranes under various pH conditions. The photosensitizers used are in most cases based on the porphyrin structure, but other compounds, of which far-red-light absorption properties are most compatible with biological tissues irradiation, have been developed, such as phthalocyanines. This paper presents physico-chemical studies of the interaction of a disulfonated aluminium phthalocyanine (AlPcS2) with human LDLs. The data obtained are compared with the parameters of the interaction of these lipoproteins with deuteroporphyrin (DP) and chlorin e6 (Ce6). A close attention is paid to the dynamic aspects of these phenomena. The data obtained on these simple systems then allowed us to interpret the sub-cellular localization of the photosensitizers on a human line of fibroblasts, and to evaluate the influence of LDLs on the intracellular distribution of the compounds. This last point is of major importance because the localization of such photosensitizers (in particular AlPcS2) in endocytic vesicles and their subsequent ability to induce a release of the contents of these vesicles - including externally added macromolecules - into the cytosol is the basis for a recent method for macromolecule activation, named photochemical internalization (PCI). PCI has been shown to potentiate the biological activity of a large variety of macromolecules. The comprehension of the mechanisms governing this particular sub-cellular localization could allow the design of better candidates for PCI.
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Affiliation(s)
- Stéphanie Bonneau
- Université Pierre et Marie Curie, Paris 6, UMR 7033, BioMoCeTi, Paris, F-75005, France.
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Mulder M, Koopmans G, Wassink G, Al Mansouri G, Simard ML, Havekes LM, Prickaerts J, Blokland A. LDL receptor deficiency results in decreased cell proliferation and presynaptic bouton density in the murine hippocampus. Neurosci Res 2007; 59:251-6. [PMID: 17720268 DOI: 10.1016/j.neures.2007.07.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2007] [Revised: 05/22/2007] [Accepted: 07/03/2007] [Indexed: 11/26/2022]
Abstract
An aberrant cholesterol metabolism in the brain may contribute to the pathogenesis of Alzheimer's disease (AD). The LDL receptor (LDLR) regulates plasma cholesterol levels and recently we and others obtained evidence that it is also involved in regulating brain cholesterol homeostasis. Moreover, we found that LDLR-deficient mice display impaired spatial memory. Because cholesterol, in part derived from cellular uptake via LDLR, is required for peripheral cell proliferation and growth, we examined the effect of absence of the LDLR on hippocampal proliferation and the density of synaptic connections. Mice deficient for the LDLR displayed a reduced number of proliferating (BrdU-labeled) cells in the hippocampus as compared to wild type control mice. In addition, the number of synaptophysin-immunoreactive presynaptic boutons in the hippocampal CA1 and the dentate gyrus (DG) areas, but not in cortical areas, was lower in the LDLR-knockout mice than in the control mice. In vitro experiments showed that LDLR activity is increased when cell growth is enhanced by the addition of N2 supplement. This further supports a role for the LDLR in the outgrowth of neurites. These findings support the notion that, similar to its role in the periphery, the LDLR is important for the cellular uptake of cholesterol in the brain and that disturbance of this process affects neuronal plasticity.
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Affiliation(s)
- Monique Mulder
- Department of Molecular Cell Biology, University of Maastricht, Maastricht, The Netherlands.
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