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Ceramide and Sphingosine-1-Phosphate in Neurodegenerative Disorders and Their Potential Involvement in Therapy. Int J Mol Sci 2022; 23:ijms23147806. [PMID: 35887154 PMCID: PMC9324343 DOI: 10.3390/ijms23147806] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 07/08/2022] [Accepted: 07/11/2022] [Indexed: 02/04/2023] Open
Abstract
Neurodegenerative disorders (ND) are progressive diseases of the nervous system, often without resolutive therapy. They are characterized by a progressive impairment and loss of specific brain regions and neuronal populations. Cellular and animal model studies have identified several molecular mechanisms that play an important role in the pathogenesis of ND. Among them are alterations of lipids, in particular sphingolipids, that play a crucial role in neurodegeneration. Overall, during ND, ceramide-dependent pro-apoptotic signalling is promoted, whereas levels of the neuroprotective spingosine-1-phosphate are reduced. Moreover, ND are characterized by alterations of the metabolism of complex sphingolipids. The finding that altered sphingolipid metabolism has a role in ND suggests that its modulation might provide a useful strategy to identify targets for possible therapies. In this review, based on the current literature, we will discuss how bioactive sphingolipids (spingosine-1-phosphate and ceramide) are involved in some ND (Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis) and their possible involvement in therapies.
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Picone P, Porcelli G, Bavisotto CC, Nuzzo D, Galizzi G, Biagio PLS, Bulone D, Di Carlo M. Synaptosomes: new vesicles for neuronal mitochondrial transplantation. J Nanobiotechnology 2021; 19:6. [PMID: 33407593 PMCID: PMC7789323 DOI: 10.1186/s12951-020-00748-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 12/05/2020] [Indexed: 12/19/2022] Open
Abstract
Background Mitochondrial dysfunction is a critical factor in the onset and progression of neurodegenerative diseases. Recently, mitochondrial transplantation has been advised as an innovative and attractive strategy to transfer and replace damaged mitochondria. Here we propose, for the first time, to use rat brain extracted synaptosomes, a subcellular fraction of isolated synaptic terminal that contains mitochondria, as mitochondrial delivery systems. Results Synaptosome preparation was validated by the presence of Synaptophysin and PSD95. Synaptosomes were characterized in terms of dimension, zeta potential, polydispersity index and number of particles/ml. Nile Red or CTX-FITCH labeled synaptosomes were internalized in LAN5 recipient cells by a mechanism involving specific protein–protein interaction, as demonstrated by loss of fusion ability after trypsin treatment and using different cell lines. The loading and release ability of the synaptosomes was proved by the presence of curcumin both into synaptosomes and LAN5 cells. The vitality of mitochondria transferred by Synaptosomes was demonstrated by the presence of Opa1, Fis1 and TOM40 mitochondrial proteins and JC-1 measurements. Further, synaptosomes deliver vital mitochondria into the cytoplasm of neuronal cells as demonstrated by microscopic images, increase of TOM 40, cytochrome c, Hexokinase II mitochondrial proteins, and presence of rat mitochondrial DNA. Finally, by using synaptosomes as a vehicle, healthy mitochondria restored mitochondrial function in cells containing rotenone or CCCp damaged mitochondria. Conclusions Taken together these results suggest that synaptosomes can be a natural vehicle for the delivery of molecules and organelles to neuronal cells. Further, the replacement of affected mitochondria with healthy ones could be a potential therapy for treating neuronal mitochondrial dysfunction-related diseases.![]()
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Affiliation(s)
- Pasquale Picone
- Istituto per la Ricerca e l' Innovazione Biomedica (IRIB) CNR, via U. La Malfa 153, 90146, Palermo, Italy
| | - Gaetana Porcelli
- Istituto per la Ricerca e l' Innovazione Biomedica (IRIB) CNR, via U. La Malfa 153, 90146, Palermo, Italy
| | - Celeste Caruso Bavisotto
- Istituto di Biofisica (IBF) (sez. Palermo) CNR, via U. La Malfa, 153, 90146, Palermo, Italy.,Dipartimento di Biomedicina, Neuroscienze, e Diagnostica Avanzata (BIND) (Sez. Anatomia Umana), Università di Palermo, via del Vespro 129, 90127, Palermo, Italy.,Istituto Euro-Mediterraneo di Scienze e Tecnologie (IEMEST), via M. Miraglia, 20, 90139, Palermo, Italy
| | - Domenico Nuzzo
- Istituto per la Ricerca e l' Innovazione Biomedica (IRIB) CNR, via U. La Malfa 153, 90146, Palermo, Italy
| | - Giacoma Galizzi
- Istituto per la Ricerca e l' Innovazione Biomedica (IRIB) CNR, via U. La Malfa 153, 90146, Palermo, Italy
| | - Pier Luigi San Biagio
- Istituto di Biofisica (IBF) (sez. Palermo) CNR, via U. La Malfa, 153, 90146, Palermo, Italy
| | - Donatella Bulone
- Istituto di Biofisica (IBF) (sez. Palermo) CNR, via U. La Malfa, 153, 90146, Palermo, Italy
| | - Marta Di Carlo
- Istituto per la Ricerca e l' Innovazione Biomedica (IRIB) CNR, via U. La Malfa 153, 90146, Palermo, Italy.
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Ahmad F, Liu P. Synaptosome as a tool in Alzheimer's disease research. Brain Res 2020; 1746:147009. [PMID: 32659233 DOI: 10.1016/j.brainres.2020.147009] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 06/21/2020] [Accepted: 07/04/2020] [Indexed: 12/29/2022]
Abstract
Synapse dysfunction is an integral feature of Alzheimer's disease (AD) pathophysiology. In fact, prodromal manifestation of structural and functional deficits in synapses much prior to appearance of overt pathological hallmarks of the disease indicates that AD might be considered as a degenerative disorder of the synapses. Several research instruments and techniques have allowed us to study synaptic function and plasticity and their alterations in pathological conditions, such as AD. One such tool is the biochemically isolated preparations of detached and resealed synaptic terminals, the "synaptosomes". Because of the preservation of many of the physiological processes such as metabolic and enzymatic activities, synaptosomes have proved to be an indispensable ex vivo model system to study synapse physiology both when isolated from fresh or cryopreserved tissues, and from animal or human post-mortem tissues. This model system has been tremendously successful in the case of post-mortem tissues because of their accessibility relative to acute brain slices or cultures. The current review details the use of synaptosomes in AD research and its potential as a valuable tool in furthering our understanding of the pathogenesis and in devising and testing of therapeutic strategies for the disease.
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Affiliation(s)
- Faraz Ahmad
- Department of Anatomy, School of Biomedical Sciences, Brain Research New Zealand, University of Otago, Dunedin, New Zealand.
| | - Ping Liu
- Department of Anatomy, School of Biomedical Sciences, Brain Research New Zealand, University of Otago, Dunedin, New Zealand
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Peña-Bautista C, Roca M, López-Cuevas R, Baquero M, Vento M, Cháfer-Pericás C. Metabolomics study to identify plasma biomarkers in alzheimer disease: ApoE genotype effect. J Pharm Biomed Anal 2019; 180:113088. [PMID: 31923717 DOI: 10.1016/j.jpba.2019.113088] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 12/03/2019] [Accepted: 12/24/2019] [Indexed: 12/17/2022]
Abstract
Alzheimer Disease (AD) is the main cause of dementia, and it has a great social and economic impact worldwide. It is a complex multifactorial disease, and we still do not know enough about its causes. For this reason, omics studies could be a useful tool for the search for new biomarkers and for enhancing the knowledge of different metabolic pathways that may be altered in the initial stages of the disease. Metabolomic analysis was carried out for plasma samples from early AD patients and healthy controls. Obtained data were normalized and analyzed by volcano plot and supervised orthogonal-least-squares-discriminant analysis. Fifteen variables were selected as the most important variables for the groups' discrimination, and the different levels of 6 identified metabolites could discriminate between patients with different ApoE4 genotypes (ε4-carriers and non ε4-carriers). In conclusion, ApoE4 genotype is associated with changes in lipid metabolomics profile in AD patients, and it could be relevant for the development of AD since early stages.
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Affiliation(s)
| | - Marta Roca
- Analytical Unit Platform, Health Research Institute La Fe, Valencia, Spain
| | | | - Miguel Baquero
- Neurology Unit, University and Polytechnic Hospital La Fe, Valencia, Spain
| | - Máximo Vento
- Neonatal Research Unit, Health Research Institute La Fe, Valencia, Spain
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Relation of Serum Plasmalogens and APOE Genotype to Cognition and Dementia in Older Persons in a Cross-Sectional Study. Brain Sci 2019; 9:brainsci9040092. [PMID: 31022959 PMCID: PMC6523320 DOI: 10.3390/brainsci9040092] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 04/19/2019] [Accepted: 04/21/2019] [Indexed: 01/18/2023] Open
Abstract
Using a community sample of 1205 elderly persons, we investigated the associations and potential interactions between Apolipoprotein E (APOE) genotype and serum phosphatidylethanolamine (PlsEtn) on cognition and dementia. For each person, APOE genotype, PlsEtn Biosynthesis value (PBV, the combination of three key PlsEtn species), cognition (the combination of five specific cognitive domains), and diagnosis of dementia was determined. APOE genotype and PBV were observed to be non-interacting (p > 0.05) and independently associated with cognition: APOE (relative to ε3ε3:ε2ε3 (Coef = 0.14, p = 4.2 × 10−2); ε3ε4/ε4ε4 (Coef = −0.22, p = 6.2 × 10−5); PBV (Coef = 0.12, p = 1.7 × 10−7) and dementia: APOE (relative to ε3ε3:ε2ε3 (Odds Ratio OR = 0.44, p = 3.0 × 10−2); ε3ε4/ε4ε4 (OR = 2.1, p = 2.2 × 10−4)); PBV (OR = 0.61, p = 3.3 × 10−6). Associations are expressed per standard deviation (SD) and adjusted for serum lipids and demographics. Due to the independent and non-interacting nature of the APOE and PBV associations, the prevalence of dementia in APOE ε3ε4/ε4ε4 persons with high PBV values (>1 SD from mean) was observed to be the same as APOE ε3ε3 persons (14.3% versus 14.0%). Similarly, the prevalence of dementia in APOE ε3ε3 persons with high PBV values was only 5.7% versus 6.7% for APOE ε2ε3 persons. The results of these analyses indicate that the net effect of APOE genotype on cognition and the prevalence of dementia is dependent upon the plasmalogen status of the person.
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Learning, memory and the expression of cholinergic components in mice are modulated by the pesticide chlorpyrifos depending upon age at exposure and apolipoprotein E (APOE) genotype. Arch Toxicol 2019; 93:693-707. [DOI: 10.1007/s00204-019-02387-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 01/10/2019] [Indexed: 12/20/2022]
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Miya Shaik M, Tamargo IA, Abubakar MB, Kamal MA, Greig NH, Gan SH. The Role of microRNAs in Alzheimer's Disease and Their Therapeutic Potentials. Genes (Basel) 2018; 9:genes9040174. [PMID: 29561798 PMCID: PMC5924516 DOI: 10.3390/genes9040174] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 03/05/2018] [Accepted: 03/05/2018] [Indexed: 12/19/2022] Open
Abstract
MicroRNAs (miRNAs) are short, endogenous, non-coding RNAs that post-transcriptionally regulate gene expression by base pairing with mRNA targets. Altered miRNA expression profiles have been observed in several diseases, including neurodegeneration. Multiple studies have reported altered expressions of miRNAs in the brains of individuals with Alzheimer’s disease (AD) as compared to those of healthy elderly adults. Some of the miRNAs found to be dysregulated in AD have been reported to correlate with neuropathological changes, including plaque and tangle accumulation, as well as altered expressions of species that are known to be involved in AD pathology. To examine the potentially pathogenic functions of several dysregulated miRNAs in AD, we review the current literature with a focus on the activities of ten miRNAs in biological pathways involved in AD pathogenesis. Comprehensive understandings of the expression profiles and activities of these miRNAs will illuminate their roles as potential therapeutic targets in AD brain and may lead to the discovery of breakthrough treatment strategies for AD.
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Affiliation(s)
- Munvar Miya Shaik
- School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian 16150, Malaysia.
| | - Ian A Tamargo
- Drug Design and Development Section, Translational Gerontology Branch, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA.
| | - Murtala B Abubakar
- Department of Physiology, Faculty of Basic Medical Sciences, College of Health Sciences, Usmanu Danfodiyo University, PMB 2254 Sokoto, Nigeria.
| | - Mohammad A Kamal
- Metabolomics and Enzymology Unit, Fundamental and Applied Biology Group, King Fahd Medical Research Center, King Abdulaziz University, P.O. Box 80216, Jeddah 21589, Saudi Arabia.
| | - Nigel H Greig
- Drug Design and Development Section, Translational Gerontology Branch, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA.
| | - Siew Hua Gan
- School of Pharmacy, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway 47500, Selangor, Malaysia.
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Ban C, Zhang Q, Feng J, Li H, Qiu Q, Tian Y, Li X. Low prevalence of lipid metabolism abnormalities in APOE ε2-genotype and male patients 60 years or older with schizophrenia. BMC Psychiatry 2017; 17:399. [PMID: 29233125 PMCID: PMC5727937 DOI: 10.1186/s12888-017-1530-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 11/07/2017] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Schizophrenia is a serious mental disorder largely manageable with atypical antipsychotics; however, these drugs have been associated with glucose/lipid metabolism issues such as diabetes and hyperlipidaemia. Apolipoprotein E (APOE) is the most abundant apolipoprotein, and APOE genotypes have been correlated with lipid metabolism phenotypes in an age-dependent manner. Studies examining the relationship between the APOE genotype and lipid abnormalities in patients with schizophrenia have been inconclusive, but primarily focused on adult patient populations. Therefore, we explored the correlations between the APOE genotype and glucose/lipid metabolism indicators and abnormalities in hospitalized patients 60 years or older with schizophrenia with a history of long-term antipsychotics use. METHODS We assessed APOE genotype, age, weight, height, blood glucose, triglycerides, cholesterol, high-density lipoprotein, and low-density lipoprotein in a total of 294 patients. APOE genotypes were divided into three groups: APOE ε2 (ε2/ε2 and ε2/ε3), APOE ε3 (ε3/ε3), and APOE ε4 (ε3/ε4 and ε4/ε4), and comparisons were conducted among these groups or according to ε2 carrier status. RESULTS APOE ε3/ε3 was the most common genotype (68.3%) and at least one ε3 allele was present in 81.8% of patients. There were no differences in antipsychotics type or dose according to the APOE genotype, but serum cholesterol values varied near significantly (P = 0.052) and low-density lipoprotein values varied significantly according to genotype (P < 0.05, lowest in the APOE ε2 genotype). Men had lower cholesterol and low-density lipoprotein levels (P < 0.05) than women. Compared to patients administered typical antipsychotics, those administered atypical antipsychotics had higher triglyceride, cholesterol, and low-density lipoprotein levels (P < 0.05). Stepwise linear regressions showed that cholesterol and low-density lipoprotein levels were influenced by sex, the APOE ε2 genotype, and atypical antipsychotics use. CONCLUSIONS In the context of atypical antipsychotics use, carriers of the APOE ε2-genotype and male patients with schizophrenia 60 years or older may be less likely to develop a lipid metabolism abnormality.
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Affiliation(s)
- Chunxia Ban
- 0000 0004 0368 8293grid.16821.3cDepartment of Psychogeriatrics, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, South Wanping Road 600, Shanghai, 200030 China ,Mental Health Center of Jiading District in Shanghai, Shanghai, 201800 China
| | - Qunying Zhang
- Mental Health Center of Fengxian District in Shanghai, Shanghai, 201400 China
| | - Jie Feng
- Mental Health Center of Jiading District in Shanghai, Shanghai, 201800 China
| | - Huijuan Li
- Mental Health Center of Jiading District in Shanghai, Shanghai, 201800 China
| | - Qi Qiu
- 0000 0004 0368 8293grid.16821.3cDepartment of Psychogeriatrics, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, South Wanping Road 600, Shanghai, 200030 China
| | - Yuan Tian
- Mental Health Center of Jiading District in Shanghai, Shanghai, 201800, China.
| | - Xia Li
- Department of Psychogeriatrics, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, South Wanping Road 600, Shanghai, 200030, China.
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Ban CX, Zhong L, Wang T, Zhu MJ, Wang JH, Zhang ZL, Wang Z, Su N, Liu YY, Shi YC, Xiao SF, Li X. Enhanced Diabetes Susceptibility in Community Dwelling Han Elders Carrying the Apolipoprotein E 3/3 Genotype. PLoS One 2016; 11:e0151336. [PMID: 26998902 PMCID: PMC4801405 DOI: 10.1371/journal.pone.0151336] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2015] [Accepted: 02/26/2016] [Indexed: 11/30/2022] Open
Abstract
Despite Apolipoprotein E (ApoE) being one of the main apolipoproteins in the blood, the association between its genotype and the high cholesterol or blood glucose levels commonly seen in clinical practice is inconclusive. Such research is also lacking in the Han population. The aim of this study was to investigate the association between APOE genotype, diabetes, and plasma glucose and lipid levels. We included 243 community-dwelling elderly residents in this study. Participant APOE genotypes were assessed and were simultaneously tested for weight, height, blood glucose, triglycerides, cholesterol, and high- and low-density lipoprotein. In addition, gender, age, years of education, cognitive function, and medical history was recorded. Subjects were divided into 3 groups based on APOE genotype: APOE ε2 group (ε2/ε2 and ε2/ε3), APOE ε3 group (ε3/ε3), and APOE ε4 group (ε2/ε4, ε3/ε4 and ε4/ε4). Comparisons between groups were conducted for the incidence of diabetes, high blood pressure, and dementia, as well as for differences in body-mass index, fasting plasma glucose, and blood lipids. The APOE ε3/ε3 genotype exhibited the highest frequency (70.4%) among the subjects. Participants in the APOE ε3 group demonstrated significantly higher levels of fasting plasma glucose than those in the APOE ε2 and APOE ε4 groups (P<0.05). The APOE ε3 group had slightly higher abnormal fasting plasma glucose values than did the APOE ε2 group (P = 0.065). Furthermore, the APOE3 genotype was significantly correlated with both fasting plasma glucose level and glucose abnormality (P< 0.05) and trended toward statistically significant correlation with diabetes (P = 0.082). The correlation between APOE2 and low low-density lipoprotein levels also approached statistical significance (P = 0.052). Thus, elderly community dwelling residents of Han ethnicity carrying the APOE ε3/ε3 genotype might have higher plasma glucose levels and a higher occurrence of diabetes.
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Affiliation(s)
- Chun-xia Ban
- Department of Psychogeriatrics, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Li Zhong
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen, China
| | - Tao Wang
- Department of Psychogeriatrics, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Min-jie Zhu
- Department of Psychogeriatrics, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jing-hua Wang
- Department of Psychogeriatrics, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhen-lian Zhang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen, China
| | - Zhe Wang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen, China
| | - Ning Su
- Department of Psychogeriatrics, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yuan-yuan Liu
- Department of Psychogeriatrics, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yan-chen Shi
- Department of Psychogeriatrics, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shi-fu Xiao
- Department of Psychogeriatrics, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xia Li
- Department of Psychogeriatrics, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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Ray S, Kassan A, Busija AR, Rangamani P, Patel HH. The plasma membrane as a capacitor for energy and metabolism. Am J Physiol Cell Physiol 2015; 310:C181-92. [PMID: 26771520 DOI: 10.1152/ajpcell.00087.2015] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
When considering which components of the cell are the most critical to function and physiology, we naturally focus on the nucleus, the mitochondria that regulate energy and apoptotic signaling, or other organelles such as the endoplasmic reticulum, Golgi, ribosomes, etc. Few people will suggest that the membrane is the most critical element of a cell in terms of function and physiology. Those that consider the membrane critical will point to its obvious barrier function regulated by the lipid bilayer and numerous ion channels that regulate homeostatic gradients. What becomes evident upon closer inspection is that not all membranes are created equal and that there are lipid-rich microdomains that serve as platforms of signaling and a means of communication with the intracellular environment. In this review, we explore the evolution of membranes, focus on lipid-rich microdomains, and advance the novel concept that membranes serve as "capacitors for energy and metabolism." Within this framework, the membrane then is the primary and critical regulator of stress and disease adaptation of the cell.
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Affiliation(s)
- Supriyo Ray
- Department of Veterans Affairs San Diego Healthcare System, San Diego, California; Department of Anesthesiology, University of California, San Diego, La Jolla, California; and
| | - Adam Kassan
- Department of Veterans Affairs San Diego Healthcare System, San Diego, California; Department of Anesthesiology, University of California, San Diego, La Jolla, California; and
| | - Anna R Busija
- Department of Veterans Affairs San Diego Healthcare System, San Diego, California; Department of Anesthesiology, University of California, San Diego, La Jolla, California; and
| | - Padmini Rangamani
- Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, California
| | - Hemal H Patel
- Department of Veterans Affairs San Diego Healthcare System, San Diego, California; Department of Anesthesiology, University of California, San Diego, La Jolla, California; and
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Ali-Rahmani F, Schengrund CL, Connor JR. HFE gene variants, iron, and lipids: a novel connection in Alzheimer's disease. Front Pharmacol 2014; 5:165. [PMID: 25071582 PMCID: PMC4086322 DOI: 10.3389/fphar.2014.00165] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Accepted: 06/24/2014] [Indexed: 12/14/2022] Open
Abstract
Iron accumulation and associated oxidative stress in the brain have been consistently found in several neurodegenerative diseases. Multiple genetic studies have been undertaken to try to identify a cause of neurodegenerative diseases but direct connections have been rare. In the iron field, variants in the HFE gene that give rise to a protein involved in cellular iron regulation, are associated with iron accumulation in multiple organs including the brain. There is also substantial epidemiological, genetic, and molecular evidence of disruption of cholesterol homeostasis in several neurodegenerative diseases, in particular Alzheimer's disease (AD). Despite the efforts that have been made to identify factors that can trigger the pathological events associated with neurodegenerative diseases they remain mostly unknown. Because molecular phenotypes such as oxidative stress, synaptic failure, neuronal loss, and cognitive decline, characteristics associated with AD, have been shown to result from disruption of a number of pathways, one can easily argue that the phenotype seen may not arise from a linear sequence of events. Therefore, a multi-targeted approach is needed to understand a complex disorder like AD. This can be achieved only when knowledge about interactions between the different pathways and the potential influence of environmental factors on them becomes available. Toward this end, this review discusses what is known about the roles and interactions of iron and cholesterol in neurodegenerative diseases. It highlights the effects of gene variants of HFE (H63D- and C282Y-HFE) on iron and cholesterol metabolism and how they may contribute to understanding the etiology of complex neurodegenerative diseases.
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Affiliation(s)
- Fatima Ali-Rahmani
- Departments of Neurosurgery, Neural and Behavioral Sciences and Pediatrics, Center for Aging and Neurodegenerative Diseases, Penn State Hershey Medical CenterHershey, PA, USA
- Departments of Biochemistry and Molecular Biology, The Pennsylvania State University College of MedicineHershey, PA, USA
| | - Cara-Lynne Schengrund
- Departments of Biochemistry and Molecular Biology, The Pennsylvania State University College of MedicineHershey, PA, USA
| | - James R. Connor
- Departments of Neurosurgery, Neural and Behavioral Sciences and Pediatrics, Center for Aging and Neurodegenerative Diseases, Penn State Hershey Medical CenterHershey, PA, USA
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Pathological roles of ceramide and its metabolites in metabolic syndrome and Alzheimer's disease. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1841:793-8. [DOI: 10.1016/j.bbalip.2013.08.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 07/30/2013] [Accepted: 08/02/2013] [Indexed: 02/03/2023]
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Wood WG, Li L, Müller WE, Eckert GP. Cholesterol as a causative factor in Alzheimer's disease: a debatable hypothesis. J Neurochem 2014; 129:559-72. [PMID: 24329875 PMCID: PMC3999290 DOI: 10.1111/jnc.12637] [Citation(s) in RCA: 136] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 11/24/2013] [Accepted: 12/09/2013] [Indexed: 12/17/2022]
Abstract
High serum/plasma cholesterol levels have been suggested as a risk factor for Alzheimer's disease (AD). Some reports, mostly retrospective epidemiological studies, have observed a decreased prevalence of AD in patients taking the cholesterol lowering drugs, statins. The strongest evidence causally linking cholesterol to AD is provided by experimental studies showing that adding/reducing cholesterol alters amyloid precursor protein (APP) and amyloid beta-protein (Ab) levels. However, there are problems with the cholesterol-AD hypothesis. Cholesterol levels in serum/plasma and brain of AD patients do not support cholesterol as a causative factor in AD.Prospective studies on statins and AD have largely failed to show efficacy. Even the experimental data are open to interpretation given that it is well-established that modification of cholesterol levels has effects on multiple proteins, not only amyloid precursor protein and Ab. The purpose of this review, therefore, was to examine the above-mentioned issues, discuss the pros and cons of the cholesterol-AD hypothesis, involvement of other lipids in the mevalonate pathway, and consider that AD may impact cholesterol homeostasis.
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Affiliation(s)
- W. Gibson Wood
- Geriatric Research, Education and Clinical Center, VAMC, Department of Pharmacology, University of Minnesota School of Medicine, Minneapolis, MN 55455 USA
| | - Ling Li
- Department of Experimental and Clinical Pharmacology, College of Pharmacy, University of Minnesota, Minneapolis, MN 55455 USA
| | - Walter E. Müller
- Department of Pharmacology, Biocenter Niederursel, Goethe University, Max-von-Laue-St. 9, 60438 Frankfurt, Germany
| | - Gunter P. Eckert
- Department of Pharmacology, Biocenter Niederursel, Goethe University, Max-von-Laue-St. 9, 60438 Frankfurt, Germany
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Marquet-de Rougé P, Clamagirand C, Facchinetti P, Rose C, Sargueil F, Guihenneuc-Jouyaux C, Cynober L, Moinard C, Allinquant B. Citrulline diet supplementation improves specific age-related raft changes in wild-type rodent hippocampus. AGE (DORDRECHT, NETHERLANDS) 2013; 35:1589-1606. [PMID: 22918749 PMCID: PMC3776113 DOI: 10.1007/s11357-012-9462-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Accepted: 07/23/2012] [Indexed: 06/01/2023]
Abstract
The levels of molecules crucial for signal transduction processing change in the brain with aging. Lipid rafts are membrane microdomains involved in cell signaling. We describe here substantial biophysical and biochemical changes occurring within the rafts in hippocampus neurons from aging wild-type rats and mice. Using continuous sucrose density gradients, we observed light-, medium-, and heavy raft subpopulations in young adult rodent hippocampus neurons containing very low levels of amyloid precursor protein (APP) and almost no caveolin-1 (CAV-1). By contrast, old rodents had a homogeneous age-specific high-density caveolar raft subpopulation containing significantly more cholesterol (CHOL), CAV-1, and APP. C99-APP-Cter fragment detection demonstrates that the first step of amyloidogenic APP processing takes place in this caveolar structure during physiological aging of the rat brain. In this age-specific caveolar raft subpopulation, levels of the C99-APP-Cter fragment are exponentially correlated with those of APP, suggesting that high APP concentrations may be associated with a risk of large increases in beta-amyloid peptide levels. Citrulline (an intermediate amino acid of the urea cycle) supplementation in the diet of aged rats for 3 months reduced these age-related hippocampus raft changes, resulting in raft patterns tightly close to those in young animals: CHOL, CAV-1, and APP concentrations were significantly lower and the C99-APP-Cter fragment was less abundant in the heavy raft subpopulation than in controls. Thus, we report substantial changes in raft structures during the aging of rodent hippocampus and describe new and promising areas of investigation concerning the possible protective effect of citrulline on brain function during aging.
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Affiliation(s)
- Perrine Marquet-de Rougé
- />EA 4466, Université Paris Descartes, Sorbonne Paris Cité, Faculté des Sciences Pharmaceutiques et Biologiques, Paris, France
| | - Christine Clamagirand
- />INSERM UMR 894, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, Paris, France
| | - Patricia Facchinetti
- />INSERM UMR 894, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, Paris, France
| | - Christiane Rose
- />INSERM UMR 894, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, Paris, France
| | | | - Chantal Guihenneuc-Jouyaux
- />EA 4064, Université Paris Descartes, Sorbonne Paris Cité, Faculté des Sciences Pharmaceutiques et Biologiques, Paris, France
| | - Luc Cynober
- />EA 4466, Université Paris Descartes, Sorbonne Paris Cité, Faculté des Sciences Pharmaceutiques et Biologiques, Paris, France
- />Service de Biochimie Hôtel-Dieu et Cochin, AP-HP, Paris, France
| | - Christophe Moinard
- />EA 4466, Université Paris Descartes, Sorbonne Paris Cité, Faculté des Sciences Pharmaceutiques et Biologiques, Paris, France
| | - Bernadette Allinquant
- />INSERM UMR 894, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, Paris, France
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15
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Hagl S, Kocher A, Schiborr C, Eckert SH, Ciobanu I, Birringer M, El-Askary H, Helal A, Khayyal MT, Frank J, Muller WE, Eckert GP. Rice bran extract protects from mitochondrial dysfunction in guinea pig brains. Pharmacol Res 2013; 76:17-27. [PMID: 23827162 DOI: 10.1016/j.phrs.2013.06.008] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 06/13/2013] [Accepted: 06/18/2013] [Indexed: 01/08/2023]
Abstract
Mitochondrial dysfunction plays a major role in the development of age-related neurodegenerative diseases and recent evidence suggests that food ingredients can improve mitochondrial function. In the current study we investigated the effects of feeding a stabilized rice bran extract (RBE) on mitochondrial function in the brain of guinea pigs. Key components of the rice bran are oryzanols, tocopherols and tocotrienols, which are supposed to have beneficial effects on mitochondrial function. Concentrations of α-tocotrienol and γ-carboxyethyl hydroxychroman (CEHC) but not γ-tocotrienol were significantly elevated in brains of RBE fed animals and thus may have provided protective properties. Overall respiration and mitochondrial coupling were significantly enhanced in isolated mitochondria, which suggests improved mitochondrial function in brains of RBE fed animals. Cells isolated from brains of RBE fed animals showed significantly higher mitochondrial membrane potential and ATP levels after sodium nitroprusside (SNP) challenge indicating resistance against mitochondrial dysfunction. Experimental evidence indicated increased mitochondrial mass in guinea pig brains, e.g. enhanced citrate synthase activity, increased cardiolipin as well as respiratory chain complex I and II and TIMM levels. In addition levels of Drp1 and fis1 were also increased in brains of guinea pigs fed RBE, indicating enhanced fission events. Thus, RBE represents a potential nutraceutical for the prevention of mitochondrial dysfunction and oxidative stress in brain aging and neurodegenerative diseases.
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16
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Yamamoto N, Matsubara T, Sobue K, Tanida M, Kasahara R, Naruse K, Taniura H, Sato T, Suzuki K. Brain insulin resistance accelerates Aβ fibrillogenesis by inducing GM1 ganglioside clustering in the presynaptic membranes. J Neurochem 2012; 121:619-28. [PMID: 22260232 DOI: 10.1111/j.1471-4159.2012.07668.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Type 2 diabetes mellitus is thought to be a significant risk factor for Alzheimer's disease. Insulin resistance also affects the central nervous system by regulating key processes, such as neuronal survival and longevity, learning and memory. However, the mechanisms underlying these effects remain uncertain. To investigate whether insulin resistance is associated with the assembly of amyloid β-protein (Aβ) at the cell surface of neurons, we inhibited insulin-signalling pathways of primary neurons. The treatments of insulin receptor (IR)-knockdown and a phosphatidylinositol 3-kinase inhibitor (LY294002), but not an extracellular signal-regulated kinase inhibitor, induced an increase in GM1 ganglioside (GM1) levels in detergent-resistant membrane microdomains of the neurons. The aged db/db mouse brain exhibited reduction in IR expression and phosphorylation of Akt, which later induced an increase in the high-density GM1-clusters on synaptosomes. Neurons treated with IR knockdown or LY294002, and synaptosomes of the aged db/db mouse brains markedly accelerated an assembly of Aβs. These results suggest that ageing and peripheral insulin resistance induce brain insulin resistance, which accelerates the assembly of Aβs by increasing and clustering of GM1 in detergent-resistant membrane microdomains of neuronal membranes.
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Affiliation(s)
- Naoki Yamamoto
- Laboratory of Neurochemistry, Department of Pharmacy, College of Pharmaceutical Sciences, Ritsumeikan University, Kusatsu, Shiga, Japan.
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17
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Apolipoprotein E level and cholesterol are associated with reduced synaptic amyloid beta in Alzheimer's disease and apoE TR mouse cortex. Acta Neuropathol 2012; 123:39-52. [PMID: 22020632 DOI: 10.1007/s00401-011-0892-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2011] [Revised: 10/12/2011] [Accepted: 10/13/2011] [Indexed: 12/31/2022]
Abstract
The apolipoprotein E4 allele (APOE4) contributes to Alzheimer's disease (AD) risk and APOE2 is protective, but the relevant cellular mechanisms are unknown. We have used flow cytometry analysis to measure apolipoprotein E (apoE) and amyloid beta peptide (Aβ) levels in large populations of synaptic terminals from AD and aged cognitively normal controls, and demonstrate that modest but significant increases in soluble apoE levels accompany elevated Aβ in AD cortical synapses and in an APP/PS1 rat model of AD. Dual labeling experiments document co-localization of apoE and Aβ in individual synapses with concentration of Aβ in a small population of apoE-positive synapses in both AD and controls. Consistent with a clearance role, the apoE level was higher in Aβ-positive synapses in control cases. In aged targeted replacement mice expressing human apoE, apoE2/4 synaptic terminals demonstrated the highest level of apoE and the lowest level of Aβ compared to apoE3/3 and apoE4/4 lines. In apoE2/4 terminals, the pattern of immunolabeling for apoE and Aβ closely resembled the pattern in human control cases, and elevated apoE was accompanied by elevated free cholesterol in apoE2/4 synaptic terminals. These results are consistent with a role for APOE in Aβ clearance in AD synapses, and suggest that optimal lipidation of apoE2 compared to E3 and E4 makes an important contribution to Aβ clearance and synaptic function.
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18
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Proteomics and bioinformatics analysis of lovastatin-induced differentiation in ARO cells. J Proteomics 2011; 75:1170-80. [PMID: 22086082 DOI: 10.1016/j.jprot.2011.10.029] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Revised: 10/22/2011] [Accepted: 10/28/2011] [Indexed: 01/05/2023]
Abstract
Lovastatin (lova), a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, can induce differentiation in cancer cells at low concentration, thus having potential to be used as an auxiliary agent in cancer therapy. However, biological networks associated with the differentiation effect of lova have not been elucidated. To investigate molecular mechanisms of lova, the present study was aimed at proteomics and bioinformatics analyses on anaplastic thyroid cancer cell line ARO differentiated with low concentration of lova. Thyroid differentiation was induced by treating ARO cells with 25 μM of lova and confirmed by checking upregulation of some thyroid differentiation markers. Gel-based proteomics analysis was then performed to identify proteins differentially expressed between undifferentiated and lova-differentiated ARO cells. Bioinformatics analysis was finally performed to estimate biological networks regulated by lova. Our results showed that lova impacted on proteins involved in protein folding, biomolecule metabolism, signal transduction, protein expression and protein degradation. Specifically, transfecting ARO cells with plasmid DNA encoding flotillin 1 (FLOT1) up-regulated the thyroid differentiation markers, indicating that FLOT1 might at least partially mediate the lova-induced thyroid differentiation. These data may shed light on the mechanism underlying lova-induced re-differentiation of thyroid cancer, and give a rationale for clinical use of lova as an auxiliary agent in cancer therapy.
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19
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Abstract
Lipids are essential for the structural and functional integrity of membranes. Membrane lipids are not randomly distributed but are localized in different domains. A common characteristic of these membrane domains is their association with cholesterol. Lipid rafts and caveolae are examples of cholesterol enriched domains, which have attracted keen interest. However, two other important cholesterol domains are the exofacial and cytofacial leaflets of the plasma membrane. The two leaflets that make up the bilayer differ in their fluidity, electrical charge, lipid distribution, and active sites of certain proteins. The synaptic plasma membrane (SPM) cytofacial leaflet contains over 85% of the total SPM cholesterol as compared with the exofacial leaflet. This asymmetric distribution of cholesterol is not fixed or immobile but can be modified by different conditions in vivo: (i) chronic ethanol consumption; (ii) statins; (iii) aging; and (iv) apoE isoform. Several potential candidates have been proposed as mechanisms involved in regulation of SPM cholesterol asymmetry: apoE, low-density lipoprotein receptor, sterol carrier protein-2, fatty acid binding proteins, polyunsaturated fatty acids, P-glycoprotein and caveolin-1. This review examines cholesterol asymmetry in SPM, potential mechanisms of regulation and impact on membrane structure and function.
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Affiliation(s)
- W Gibson Wood
- Department of Pharmacology, University of Minnesota, School of Medicine, Minneapolis, MN 55455, USA.
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20
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Schengrund CL. Lipid rafts: Keys to neurodegeneration. Brain Res Bull 2010; 82:7-17. [DOI: 10.1016/j.brainresbull.2010.02.013] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2009] [Revised: 02/16/2010] [Accepted: 02/23/2010] [Indexed: 01/11/2023]
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21
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Burns MP, Rebeck GW. Intracellular cholesterol homeostasis and amyloid precursor protein processing. Biochim Biophys Acta Mol Cell Biol Lipids 2010; 1801:853-9. [PMID: 20304094 DOI: 10.1016/j.bbalip.2010.03.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2010] [Revised: 03/03/2010] [Accepted: 03/04/2010] [Indexed: 01/11/2023]
Abstract
Many preclinical and clinical studies have implied a role for cholesterol in the pathogenesis of Alzheimer's disease (AD). In this review we will discuss the movement of intracellular cholesterol and how normal distribution, transport, and export of cholesterol are vital for regulation of the AD related protein, Abeta. We focus on cholesterol distribution in the plasma membrane, transport through the endosomal/lysosomal system, control of cholesterol intracellular signaling at the endoplasmic reticulum and Golgi, the HMG-CoA reductase pathway and finally export of cholesterol from the cell.
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Affiliation(s)
- Mark P Burns
- Georgetown University Medical Center, Department of Neuroscience, Washington, DC 20057, USA.
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22
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Increased membrane cholesterol might render mature hippocampal neurons more susceptible to beta-amyloid-induced calpain activation and tau toxicity. J Neurosci 2009; 29:4640-51. [PMID: 19357288 DOI: 10.1523/jneurosci.0862-09.2009] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A growing body of evidence suggests that beta-amyloid (Abeta), the main component of senile plaques, induces abnormal posttranslational processing of the microtubule-associated protein tau. We have recently described that, in addition to increasing tau phosphorylation, Abeta enhanced calpain activity leading to the generation of a toxic 17 kDa tau fragment in cultured hippocampal neurons. How aging, the greatest Alzheimer's disease (AD) risk factor, might regulate this proteolytic event remains unknown. In this study, we assessed the susceptibility of cultured hippocampal neurons to Abeta-dependent 17 kDa tau production at different developmental stages. Our results revealed that mature neurons were more susceptible to Abeta-induced calpain activation leading to the generation of this fragment than young neurons. In addition, the production of this fragment correlated with a decrease in cell viability in mature hippocampal neurons. Second, we determined whether membrane cholesterol, a suspect player in AD, might mediate these age-dependent differences in Abeta-induced calpain activation. Filipin staining and an Amplex Red cholesterol assay showed that mature neuron membrane cholesterol levels were significantly higher than those detected in young ones. Furthermore, decreasing membrane cholesterol in mature neurons reduced their susceptibility to Abeta-dependent calpain activation, 17 kDa tau production, and cell death, whereas increasing membrane cholesterol in young neurons enhanced these Abeta-mediated cellular processes. Finally, fura-2 calcium imaging indicated that membrane cholesterol alterations might change the vulnerability of cells to Abeta insult by altering calcium influx. Together these data suggested a potential role of cholesterol in linking aging to Abeta-induced tau proteolysis in the context of AD.
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23
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Persaud-Sawin DA, Lightcap S, Harry GJ. Isolation of rafts from mouse brain tissue by a detergent-free method. J Lipid Res 2008; 50:759-67. [PMID: 19060326 DOI: 10.1194/jlr.d800037-jlr200] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Membrane rafts are rich in cholesterol and sphingolipids and have specific proteins associated with them. Due to their small size, their identification and isolation have proved to be problematic. Their insolubility in nonionic detergents, such as Triton-X 100, at 4 degrees C has been the most common means of isolation. However, detergent presence can produce artifacts or interfere with ganglioside distribution. The direction is therefore toward the use of detergent-free protocols. We report an optimized method of raft isolation from lipid-rich brain tissue using a detergent-free method. We compared this to Triton-X 100-based isolation along sucrose or Optiprep gradients using the following endpoints: low protein content, high cholesterol content, presence of Flotillin 1 (Flot1), and absence of transferrin receptor (TfR) proteins. These criteria were met in raft fractions isolated in a detergent-free buffer along a sucrose gradient of 5%/35%/42.5%. The use of optiprep gave less consistent results with respect to protein distribution. We demonstrate that clean raft fractions with minimal myelin contamination can be reproducibly obtained in the top three low-density fractions along a sucrose step gradient.
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Affiliation(s)
- Dixie-Ann Persaud-Sawin
- Laboratory of Molecular Toxicology/Neurotoxicology Group, National Institute of Environmental Health Sciences, RTP, NC 27709, USA.
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24
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Yamamoto N, Matsubara T, Sato T, Yanagisawa K. Age-dependent high-density clustering of GM1 ganglioside at presynaptic neuritic terminals promotes amyloid beta-protein fibrillogenesis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2008; 1778:2717-26. [PMID: 18727916 DOI: 10.1016/j.bbamem.2008.07.028] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2008] [Revised: 07/15/2008] [Accepted: 07/30/2008] [Indexed: 11/25/2022]
Abstract
The deposition of amyloid beta-protein (Abeta) is an invariable feature of Alzheimer's disease (AD); however, the biological mechanism underlying Abeta assembly into fibrils in the brain remains unclear. Here, we show that a high-density cluster of GM1 ganglioside (GM1), which was detected by the specific binding of a novel peptide (p3), appeared selectively on synaptosomes prepared from aged mouse brains. Notably, the synaptosomes bearing the high-density GM1 cluster showed extraordinary potency to induce Abeta assembly, which was suppressed by an antibody specific to GM1-bound Abeta, an endogenous seed for AD amyloid. Together with evidence that Abeta deposition starts at presynaptic terminals in the AD brain and that GM1 levels significantly increase in amyloid-positive synaptosomes prepared from the AD brain, our results suggest that the age-dependent high-density GM1 clustering at presynaptic neuritic terminals is a critical step for Abeta deposition in AD.
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Affiliation(s)
- Naoki Yamamoto
- Department of Alzheimer's Disease Research, National Institute for Longevity Sciences, National Center for Geriatrics and Gerontology, Obu 474-8522, Japan
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25
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Yu H, Wakim B, Li M, Halligan B, Tint GS, Patel SB. Quantifying raft proteins in neonatal mouse brain by 'tube-gel' protein digestion label-free shotgun proteomics. Proteome Sci 2007; 5:17. [PMID: 17892558 PMCID: PMC2045652 DOI: 10.1186/1477-5956-5-17] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2007] [Accepted: 09/24/2007] [Indexed: 02/08/2023] Open
Abstract
Background The low concentration and highly hydrophobic nature of proteins in lipid raft samples present significant challenges for the sensitive and accurate proteomic analyses of lipid raft proteins. Elimination of highly enriched lipids and interfering substances from raft samples is generally required before mass spectrometric analyses can be performed, but these procedures often lead to excessive protein loss and increased sample variability. For accurate analyses of the raft proteome, simplified protocols are needed to avoid excessive sample handling and purification steps. Results We have devised a simple protocol using a 'tube-gel' protein digestion that, when combined with mass spectrometry, can be used to obtain comprehensive and reproducible identification and quantitation of the lipid raft proteome prepared from neonatal mouse brain. Lipid rafts (detergent-resistant membranes using Triton X-100 extraction) prepared from neonatal mouse brain were directly incorporated into a polyacrylamide tube-gel matrix without prior protein separation. After in-gel digestion of proteins, nanospray LC-MS/MS was used to analyze the extracted peptides, and the resulting spectra were searched to identify the proteins present in the sample. Using the standard 'label-free' proteomics approach, the total number of MS/MS spectra for the identified proteins was used to provide a measure of relative protein abundances. This approach was successfully applied to lipid rafts prepared from neonatal mouse brain. A total of 216 proteins were identified: 127 proteins (58.8%) were predicted to be membrane proteins, or membrane-associated proteins and 175 proteins (~80%) showed less than a 2-fold variation in the relative abundance in replicate samples. Conclusion The tube-gel protein digestion protocol coupled with nanospray LC-MS/MS (TubeGeLC-MS/MS) offers a simple and reproducible method for identifying and quantifying the changes of relative abundances in lipid raft proteins from neonatal mouse brain and could become a useful approach for studying lipid raft proteins from various tissues.
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Affiliation(s)
- Hongwei Yu
- Division of Endocrinology, Metabolism and Nutrition, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Bassam Wakim
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Man Li
- Division of Endocrinology, Metabolism and Nutrition, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Qilu Hospital, Shandong University, 44 West Wenhua Road, Jinan, 250012, P. R. China
| | - Brian Halligan
- National Center for Proteomics Research, Biotechnology and Bioinformatics Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - G Stephen Tint
- Research Service, Department of Veterans Affairs New Jersey Health Care System, East Orange, NJ 07018, USA, and Department of Medicine, UMDNJ-New Jersey Medical School, Newark, NJ 07103-2714, USA
| | - Shailendra B Patel
- Division of Endocrinology, Metabolism and Nutrition, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Department of Veterans Affairs, Clement J. Zablocki Medical Center, Milwaukee, WI 53295, USA
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26
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Eckert GP, Vardanian L, Rebeck GW, Burns MP. Regulation of central nervous system cholesterol homeostasis by the liver X receptor agonist TO-901317. Neurosci Lett 2007; 423:47-52. [PMID: 17662526 DOI: 10.1016/j.neulet.2007.05.063] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2006] [Revised: 05/15/2007] [Accepted: 05/23/2007] [Indexed: 11/17/2022]
Abstract
The nuclear oxysterol receptors known as liver X receptors (LXR) are responsible for regulating genes involved in cholesterol homeostasis. Two subtypes exist, LXR-alpha and LXR-beta, both of which are expressed in the central nervous system (CNS). Activation of LXR causes an increase in mechanisms involved in cholesterol efflux, including ATP-binding cassette transporters (ABC)-A1 and ABC-G1. Although LXR agonists have been found to induce gene expression for ABC-A1 and ABC-G1 in the CNS, no functional response has been recorded. In this study, we show that an LXR agonist (TO-901317) increases protein levels of the cholesterol transporters ABC-A1 and ABC-G1, as well as the cholesterol chaperone protein apolipoprotein E (apoE). These changes are associated with a decrease in cholesterol levels from isolated cortical synaptosomal plasma membranes. LXR activation occurs in response to increased cholesterol levels in cells. However, while data exists on how LXR alter cholesterol efflux, there is no data on whether these receptors alter production of cholesterol. We found that TO-901317 increases HMG-CoA reductase activity, the rate-limiting step of cholesterol production in vivo. This finding was duplicated in an in vitro system. Although high concentrations (>1 microM) of TO-901317 were required to induce HMG-CoA reductase activity, these changes only occurred in the presence of apolipoprotein AI, suggesting that cholesterol efflux is required for this effect to occur. These data show that the LXR agonist TO-901317 is capable of reducing cholesterol in neurons of the CNS.
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Affiliation(s)
- Gunter P Eckert
- Department of Pharmacology, ZAFES, Biocenter Niederursel, University of Frankfurt, Frankfurt, Germany
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27
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Morishima-Kawashima M, Han X, Tanimura Y, Hamanaka H, Kobayashi M, Sakurai T, Yokoyama M, Wada K, Nukina N, Fujita SC, Ihara Y. Effects of human apolipoprotein E isoforms on the amyloid beta-protein concentration and lipid composition in brain low-density membrane domains. J Neurochem 2007; 101:949-58. [PMID: 17472586 PMCID: PMC2151839 DOI: 10.1111/j.1471-4159.2006.04400.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Apolipoprotein E4 (apoE4) encoded by epsilon 4 allele is a strong genetic risk factor for Alzheimer's disease (AD). ApoE4 carriers have accelerated amyloid beta-protein (A beta) deposition in their brains, which may account for their unusual susceptibility to AD. We hypothesized that the accelerated A beta deposition in the brain of apoE4 carriers is mediated through cholesterol-enriched low-density membrane (LDM) domains. Thus, the concentrations of A beta and various lipids in LDM domains were quantified in the brains of homozygous apoE3 and apoE4 knock-in (KI) mice, and in the brains of those mice bred with beta-amyloid precursor protein (APP) transgenic mice (Tg2576). The A beta 40 and A beta 42 concentrations and the A beta 42 proportions in LDM domains did not differ between apoE3 and apoE4 KI mice up to 18 months of age. The A beta 40 concentration in the LDM domains was slightly, but significantly higher in apoE3/APP mice than in apoE4/APP mice. The lipid composition of LDM domains was modulated in an apoE isoform-specific manner, but its significance for A beta deposition remains unknown. These data show that the apoE isoform-specific effects on the A beta concentration in LDM domains do not occur in KI mouse models.
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Affiliation(s)
| | - Xianlin Han
- Division of Bioorganic Chemistry and Molecular Pharmacology, Department of Internal Medicine, Washington University School of Medicine, St Louis, Missouri, USA
| | - Yu Tanimura
- Department of Neuropathology, Faculty of Medicine, University of Tokyo, Tokyo, Japan
| | - Hiroki Hamanaka
- Molecular Neuropathology Group, RIKEN Brain Science Institute, Saitama, Japan
- Mitsubishi Kagaku Institute of Life Sciences, Tokyo, Japan
| | | | - Takashi Sakurai
- Molecular Neuropathology Group, RIKEN Brain Science Institute, Saitama, Japan
| | | | - Koji Wada
- Molecular Neuropathology Group, RIKEN Brain Science Institute, Saitama, Japan
| | - Nobuyuki Nukina
- Molecular Neuropathology Group, RIKEN Brain Science Institute, Saitama, Japan
| | | | - Yasuo Ihara
- Department of Neuropathology, Faculty of Medicine, University of Tokyo, Tokyo, Japan
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28
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van Meer P, Pfankuch T, Raber J. Reduced histamine levels and H3receptor antagonist-induced histamine release in the amygdala of Apoe?/? mice. J Neurochem 2007; 103:124-30. [PMID: 17573822 DOI: 10.1111/j.1471-4159.2007.04705.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The histamine H(3) receptor is a constitutively active G protein-coupled receptor for the neurotransmitter histamine that serves a negative feedback function. A role for the histamine H(3) receptor has been suggested in neurodegenerative diseases, such as Parkinsons disease and Alzheimer's disease. Mice deficient in apolipoprotein E (apoE), a protein involved in development, regeneration, neurite outgrowth, and neuroprotection, show increased measures of anxiety and reduced sensitivity to effects of histamine H(3) receptor antagonists on measures of anxiety. In this study, we tested whether in mice lacking apoE (Apoe-/-) histamine levels and histamine release in brain areas involved in the regulation of anxiety are altered. H(3) receptor antagonist-induced histamine release was lower in the amygdala of Apoe-/- than wild-type mice. In contrast, there were no genotype differences in histamine release in the hypothalamus. Consistent with these data, histamine immunohistochemistry revealed lower total and synaptic histamine levels in the central nucleus of the amygdala of Apoe-/- than wild-type mice. Such changes were not seen in the hypothalamus, hippocampus, or cortex. In Apoe-/- mice, chronically decreased histamine levels and reduced histamine release in the amygdala might contribute to increased measures of anxiety.
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Affiliation(s)
- Peter van Meer
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, Oregon, USA
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29
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Poli M, Gatta LB, Lovati C, Mariani C, Galimberti D, Scarpini E, Biunno I, Musicco M, Dominici R, Albertini A, Finazzi D. Interaction between the APOE epsilon4 allele and the APH-1b c + 651T > G SNP in Alzheimer's disease. Neurobiol Aging 2007; 29:1494-501. [PMID: 17466415 DOI: 10.1016/j.neurobiolaging.2007.03.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/10/2007] [Indexed: 10/23/2022]
Abstract
The gamma-secretase complex is a multimeric aspartyl protease which plays a pivotal role in the production of amyloid beta-peptide, the main component of senile plaques in Alzheimer's disease (AD). APH-1a and APH-1b have been recently identified as important subunits of the gamma-secretase complex. We previously studied sequence variations in both genes and their association with AD in a small Italian population. The rare polymorphism c + 651T > G in APH-1b showed a possible interaction with the Apolipoprotein E (APOE) epsilon4 allele in the AD population sample. We extended our genetic analysis to 449 AD patients and 435 controls and, in AD cases, we found a significant interaction (P=0.001) between the allelic variants in the two genes, resulting in a marked increase of the relative risk for AD (OR=28.6). Despite the amino acid substitution does not seem to modify either the intracellular localization or the half-life of APH-1b protein, these data suggest that a cooperative mechanism involving APOE and APH-1b plays a role in the susceptibility to develop AD.
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Affiliation(s)
- Maura Poli
- Section of Chemistry, Faculty of Medicine, University of Brescia, viale Europa 11, 25123 Brescia, Italy
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Kern A, Roempp B, Prager K, Walter J, Behl C. Down-regulation of Endogenous Amyloid Precursor Protein Processing due to Cellular Aging. J Biol Chem 2006; 281:2405-13. [PMID: 16303768 DOI: 10.1074/jbc.m505625200] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Processing of amyloid precursor protein (APP) is a well acknowledged central pathogenic mechanism in Alzheimer disease. However, influences of age-associated cellular alterations on the biochemistry of APP processing have not been studied in molecular detail so far. Here, we report that processing of endogenous APP is down-regulated during the aging of normal human fibroblasts (IMR-90). The generation of intracellular APP cleavage products C99, C83, and AICD gradually declines with increasing life span and is accompanied by a reduced secretion of soluble APP (sAPP) and sAPPalpha. Further, the maturation of APP was reduced in senescent cells, which has been shown to be directly mediated by age-associated increased cellular cholesterol levels. Of the APP processing secretases, protein levels of constituents of the gamma-secretase complex, presenilin-1 (PS1) and nicastrin, were progressively reduced during aging, resulting in a progressive decrease in gamma-secretase enzymatic activity. ADAM10 (a disintegrin and metalloprotease 10) and BACE (beta-site APP-cleaving enzyme) protein levels exhibited no age-associated regulation, but interestingly, BACE enzymatic activity was increased in aged cells. PS1 and BACE are located in detergent-resistant membranes (DRMs), well structured membrane microdomains exhibiting high levels of cholesterol, and caveolin-1. Although total levels of both structural components of DRMs were up-regulated in aged cells, their particular DRM association was decreased. This age-dependent membrane modification was associated with an altered distribution of PS1 and BACE between DRM and non-DRM fractions, very likely affecting their APP processing potential. In conclusion, we have found a significant modulation of endogenous APP processing and maturation in human fibroblasts caused by age-associated alterations in cellular biochemistry.
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Affiliation(s)
- Andreas Kern
- Institute for Physiological Chemistry and Pathobiochemistry, Johannes Gutenberg University Mainz, 55099 Mainz, Germany
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Conboy L, Murphy KJ, Regan CM. Amyloid precursor protein expression in the rat hippocampal dentate gyrus modulates during memory consolidation. J Neurochem 2005; 95:1677-88. [PMID: 16236032 DOI: 10.1111/j.1471-4159.2005.03484.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Despite advances in our understanding of the basic biology of amyloid precursor protein (APP), the normal physiological function(s) of APP in learning and memory remains unclear. Here we show increased APP degradation in the hippocampus to be associated with the consolidation of a passive avoidance response. Neurone-specific APP695 expression became transiently reduced 2-4 h post-training through association with endosomal adaptin proteins and enhanced internalization. By contrast, internalization of glial-associated APP containing a Kunitz protease inhibitor-like domain (APP-KPI) was dependent on the low-density lipoprotein receptor-related protein (LRP). In addition, LRP expression and association with apolipoprotein E increased in the 2-4 h post-training period. The LRP antagonist receptor-associated protein prevented the APP-KPI internalization and LRP-apolipoprotein E association and this resulted in amnesia. Degradation of APP695 and APP-KPI did not appear to be related to alpha-secretase activity, as no learning-associated increase of secreted APP was observed in the CSF. Moreover, as internalization of APP isoforms was observed only in dentate gyrus, it probably relates to the learning-associated restructuring of the perforant path terminals. Memory-associated APP processing in both neuronal and glial compartments points to a role for glial unsheathing of synaptic connections, an event required for the synaptic restructuring that accompanies memory consolidation. These observations may have a direct relevance to understanding the pathophysiology of Alzheimer's disease as beta/gamma-secretase-derived beta-amyloid is formed following internalization of cell surface APP into the endosomal compartment.
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Affiliation(s)
- Lisa Conboy
- Applied Neurotherapeutics Research Group, Department of Pharmacology, Conway Institute, University College Dublin, Belfield, Dublin, Ireland
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