1
|
Newton VL, Riba-Garcia I, Griffiths CEM, Rawlings AV, Voegeli R, Unwin RD, Sherratt MJ, Watson REB. Mass spectrometry-based proteomics reveals the distinct nature of the skin proteomes of photoaged compared to intrinsically aged skin. Int J Cosmet Sci 2019; 41:118-131. [PMID: 30661253 DOI: 10.1111/ics.12513] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 12/15/2018] [Indexed: 12/15/2022]
Abstract
OBJECTIVE With increasing age, skin is subject to alterations in its organization, which impact on its function as well as having clinical consequences. Proteomics is a useful tool for non-targeted, semi-quantitative simultaneous investigation of high numbers of proteins. In the current study, we utilize proteomics to characterize and contrast age-associated differences in photoexposed and photoprotected skin, with a focus on the epidermis, dermal-epidermal junction and papillary dermis. METHODS Skin biopsies from buttock (photoprotected) and forearm (photoexposed) of healthy volunteers (aged 18-30 or ≥65 years) were transversely sectioned from the stratum corneum to a depth of 250 μm. Following SDS-PAGE, each sample lane was segmented prior to analysis by liquid chromatography-mass spectrometry/mass spectrometry. Pathway analysis was carried out using Ingenuity IPA. RESULTS Comparison of skin proteomes at buttock and forearm sites revealed differences in relative protein abundance. Ageing in skin on the photoexposed forearm resulted in 80% of the altered proteins being increased with age, in contrast to the photoprotected buttock where 74% of altered proteins with age were reduced. Functionally, age-altered proteins in the photoexposed forearm were associated with conferring structure, energy and metabolism. In the photoprotected buttock, proteins associated with gene expression, free-radical scavenging, protein synthesis and protein degradation were most frequently altered. CONCLUSION This study highlights the necessity of not considering photoageing as an accelerated intrinsic ageing, but as a distinct physiological process.
Collapse
Affiliation(s)
- V L Newton
- Centre for Dermatology Research, Division of Musculoskeletal & Dermatological Sciences, School of Biological Sciences, Manchester Academic Health Science Centre, University of Manchester, and Salford Royal NHS Foundation Trust, Manchester, UK.,NIHR Manchester Biomedical Research Centre, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK
| | - I Riba-Garcia
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Core Technology facility (3rd Floor), 46 Grafton Street, Manchester, M13 9NT, UK
| | - C E M Griffiths
- Centre for Dermatology Research, Division of Musculoskeletal & Dermatological Sciences, School of Biological Sciences, Manchester Academic Health Science Centre, University of Manchester, and Salford Royal NHS Foundation Trust, Manchester, UK.,NIHR Manchester Biomedical Research Centre, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK
| | | | - R Voegeli
- DSM Nutritional Products Ltd, Kaiseraugst, Switzerland
| | - R D Unwin
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Core Technology facility (3rd Floor), 46 Grafton Street, Manchester, M13 9NT, UK
| | - M J Sherratt
- Division of Cell Matrix Biology and Regenerative Medicine, School of Biological Sciences, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK
| | - R E B Watson
- Centre for Dermatology Research, Division of Musculoskeletal & Dermatological Sciences, School of Biological Sciences, Manchester Academic Health Science Centre, University of Manchester, and Salford Royal NHS Foundation Trust, Manchester, UK.,NIHR Manchester Biomedical Research Centre, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK
| |
Collapse
|
2
|
Li N, Hu P, Xu T, Chen H, Chen X, Hu J, Yang X, Shi L, Luo JH, Xu J. iTRAQ-based Proteomic Analysis of APPSw,Ind Mice Provides Insights into the Early Changes in Alzheimer's Disease. Curr Alzheimer Res 2018; 14:1109-1122. [PMID: 28730955 PMCID: PMC5676024 DOI: 10.2174/1567205014666170719165745] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 06/13/2017] [Accepted: 06/29/2017] [Indexed: 01/17/2023]
Abstract
BACKGROUND Several proteins have been identified as potential diagnostic biomarkers in imaging, genetic, or proteomic studies in Alzheimer disease (AD) patients and mouse models. However, biomarkers for presymptom diagnosis of AD are still under investigation, as are the presymptom molecular changes in AD pathogenesis. OBJECTIVE In this study, we aim to analyzed the early proteomic changes in APPSw,Ind mice and to conduct further functional studies on interesting proteins. METHODS We used the isobaric tags for relative and absolute quantitation (iTRAQ) approach combined with mass spectrometry to examine the early proteomic changes in hippocampi of APPSw,Ind mice. Quantitative reverse transcription polymerase chain reaction (RT-PCR) and immuno-blotting were performed for further validation. Finally, the functions of interesting proteins β-spectrin and Rab3a in APP trafficking and processing were tested by shRNA knockdown, in N2A cells stably expressing β-amyloid precursor protein (APP). RESULTS The iTRAQ and RT-PCR results revealed the detailed molecular changes in oxidative stress, myelination, astrocyte activation, mTOR signaling and Rab3-dependent APP trafficking in the early stage of AD progression. Knock down of β -spectrin and Rab3a finally led to increased APP fragment production, indicating key roles of β-spectrin and Rab3a in regulating APP processing. CONCLUSION Our study provides the first insights into the proteomic changes that occur in the hippocampus in the early stages of the AD mouse model. In addition to improving the understanding of molecular alterations and functional cascades involved in early AD pathogenesis, our findings raise the possibility of developing potential biomarkers and therapeutic targets for early AD.
Collapse
Affiliation(s)
- Nan Li
- Center of Neuroscience, Key Laboratory of Medical Neurobiology of Ministry of Health, Zhejiang Province Key Laboratory of Neurobiology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058. China
| | - Pinghong Hu
- Center of Neuroscience, Key Laboratory of Medical Neurobiology of Ministry of Health, Zhejiang Province Key Laboratory of Neurobiology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058. China
| | - Tiantian Xu
- Center of Neuroscience, Key Laboratory of Medical Neurobiology of Ministry of Health, Zhejiang Province Key Laboratory of Neurobiology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058. China
| | - Huan Chen
- Center of Neuroscience, Key Laboratory of Medical Neurobiology of Ministry of Health, Zhejiang Province Key Laboratory of Neurobiology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058. China
| | - Xiaoying Chen
- Center of Neuroscience, Key Laboratory of Medical Neurobiology of Ministry of Health, Zhejiang Province Key Laboratory of Neurobiology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058. China
| | - Jianwen Hu
- Shanghai Applied Protein Technology Co., Ltd., Shanghai. China
| | - Xifei Yang
- Key Laboratory of Modern Toxicology of Shenzhen, Medical Key Laboratory of Guangdong Province, Medical Key Laboratory of Health Toxicology of Shenzhen, Shenzhen Center for Disease Control and Prevention, Shenzhen. China
| | - Lei Shi
- Key Laboratory of Modern Toxicology of Shenzhen, Medical Key Laboratory of Guangdong Province, Medical Key Laboratory of Health Toxicology of Shenzhen, Shenzhen Center for Disease Control and Prevention, Shenzhen. China
| | - Jian-Hong Luo
- Center of Neuroscience, Key Laboratory of Medical Neurobiology of Ministry of Health, Zhejiang Province Key Laboratory of Neurobiology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058. China
| | - Junyu Xu
- Center of Neuroscience, Zhejiang University, 866 Yuhangtang Road, Hangzhou. China
| |
Collapse
|
3
|
Hsu WCJ, Nilsson CL, Laezza F. Role of the axonal initial segment in psychiatric disorders: function, dysfunction, and intervention. Front Psychiatry 2014; 5:109. [PMID: 25191280 PMCID: PMC4139700 DOI: 10.3389/fpsyt.2014.00109] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Accepted: 08/06/2014] [Indexed: 12/22/2022] Open
Abstract
The progress of developing effective interventions against psychiatric disorders has been limited due to a lack of understanding of the underlying cellular and functional mechanisms. Recent research findings focused on exploring novel causes of psychiatric disorders have highlighted the importance of the axonal initial segment (AIS), a highly specialized neuronal structure critical for spike initiation of the action potential. In particular, the role of voltage-gated sodium channels, and their interactions with other protein partners in a tightly regulated macromolecular complex has been emphasized as a key component in the regulation of neuronal excitability. Deficits and excesses of excitability have been linked to the pathogenesis of brain disorders. Identification of the factors and regulatory pathways involved in proper AIS function, or its disruption, can lead to the development of novel interventions that target these mechanistic interactions, increasing treatment efficacy while reducing deleterious off-target effects for psychiatric disorders.
Collapse
Affiliation(s)
- Wei-Chun Jim Hsu
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch at Galveston, Galveston, TX, USA
- Graduate Program in Biochemistry and Molecular Biology, The University of Texas Medical Branch at Galveston, Galveston, TX, USA
- M.D.–Ph.D. Combined Degree Program, The University of Texas Medical Branch at Galveston, Galveston, TX, USA
| | - Carol Lynn Nilsson
- Department of Pharmacology and Toxicology, The University of Texas Medical Branch at Galveston, Galveston, TX, USA
- Sealy Center for Molecular Medicine, The University of Texas Medical Branch at Galveston, Galveston, TX, USA
| | - Fernanda Laezza
- Department of Pharmacology and Toxicology, The University of Texas Medical Branch at Galveston, Galveston, TX, USA
- Center for Addiction Research, The University of Texas Medical Branch at Galveston, Galveston, TX, USA
- Center for Biomedical Engineering, The University of Texas Medical Branch at Galveston, Galveston, TX, USA
- Mitchell Center for Neurodegenerative Diseases, The University of Texas Medical Branch at Galveston, Galveston, TX, USA
| |
Collapse
|
4
|
Affiliation(s)
- John P. Blass
- Burke Medical Research Institute, Cornell University Medical College, White Plains, New York, U.S.A
| |
Collapse
|
5
|
Cai Y, Zhu HX, Li JM, Luo XG, Patrylo PR, Rose GM, Streeter J, Hayes R, Wang KKW, Yan XX, Jeromin A. Age-related intraneuronal elevation of αII-spectrin breakdown product SBDP120 in rodent forebrain accelerates in 3×Tg-AD mice. PLoS One 2012; 7:e37599. [PMID: 22723836 PMCID: PMC3377681 DOI: 10.1371/journal.pone.0037599] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Accepted: 04/23/2012] [Indexed: 11/24/2022] Open
Abstract
Spectrins line the intracellular surface of plasmalemma and play a critical role in supporting cytoskeletal stability and flexibility. Spectrins can be proteolytically degraded by calpains and caspases, yielding breakdown products (SBDPs) of various molecular sizes, with SBDP120 being largely derived from caspase-3 cleavage. SBDPs are putative biomarkers for traumatic brain injury. The levels of SBDPs also elevate in the brain during aging and perhaps in Alzheimer’s disease (AD), although the cellular basis for this change is currently unclear. Here we examined age-related SBDP120 alteration in forebrain neurons in rats and in the triple transgenic model of AD (3×Tg-AD) relative to non-transgenic controls. SBDP120 immunoreactivity (IR) was found in cortical neuronal somata in aged rats, and was prominent in the proximal dendrites of the olfactory bulb mitral cells. Western blot and densitometric analyses in wild-type mice revealed an age-related elevation of intraneuronal SBDP120 in the forebrain which was more robust in their 3×Tg-AD counterparts. The intraneuronal SBDP120 occurrence was not spatiotemporally correlated with transgenic amyloid precursor protein (APP) expression, β-amyloid plaque development, or phosphorylated tau expression over various forebrain regions or lamina. No microscopically detectable in situ activated caspase-3 was found in the nuclei of SBDP120-containing neurons. The present study demonstrates the age-dependent intraneuronal presence of an αII-spectrin cleavage fragment in mammalian forebrain which is exacerbated in a transgenic model of AD. This novel neuronal alteration indicates that impairments in membrane protein metabolism, possibly due to neuronal calcium mishandling and/or enhancement of calcium sensitive proteolysis, occur during aging and in transgenic AD mice.
Collapse
Affiliation(s)
- Yan Cai
- Department of Anatomy and Neurobiology, Central South University Xiangya Medical School, Changsha, Hunan, China
| | - Hai-Xia Zhu
- Department of Neurology, The Third Xiangya Hospital, Changsha, Hunan, China
| | - Jian-Ming Li
- Neuroscience Research Center, Changsha Medical University, Changsha, Hunan, China
| | - Xue-Gang Luo
- Department of Anatomy and Neurobiology, Central South University Xiangya Medical School, Changsha, Hunan, China
| | - Peter R. Patrylo
- Departments of Anatomy & Physiology, Southern Illinois University School of Medicine, Carbondale, Illinois, United States of America
- Center for Integrated Research in Cognitive and Neural Sciences, Southern Illinois University School of Medicine, Carbondale, Illinois, United States of America
| | - Gregory M. Rose
- Departments of Anatomy & Physiology, Southern Illinois University School of Medicine, Carbondale, Illinois, United States of America
- Center for Integrated Research in Cognitive and Neural Sciences, Southern Illinois University School of Medicine, Carbondale, Illinois, United States of America
| | | | - Ron Hayes
- Banyan Biomarkers, Alachua, Florida, United States of America
| | | | - Xiao-Xin Yan
- Department of Anatomy and Neurobiology, Central South University Xiangya Medical School, Changsha, Hunan, China
- Center for Integrated Research in Cognitive and Neural Sciences, Southern Illinois University School of Medicine, Carbondale, Illinois, United States of America
- * E-mail: (XXY); (AJ)
| | - Andreas Jeromin
- Banyan Biomarkers, Alachua, Florida, United States of America
- * E-mail: (XXY); (AJ)
| |
Collapse
|
6
|
Spectrin Breakdown Products (SBDPs) as Potential Biomarkers for Neurodegenerative Diseases. ACTA ACUST UNITED AC 2012; 1:85-93. [PMID: 23710421 DOI: 10.1007/s13670-012-0009-2] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The world's human population ages rapidly thanks to the great advance in modern medicine. While more and more body system diseases become treatable and curable, age-related neurodegenerative diseases remain poorly understood mechanistically, and are desperately in need of preventive and therapeutic interventions. Biomarker development consists of a key part of concerted effort in combating neurodegenerative diseases. In many chronic neurodegenerative conditions, neuronal damage/death occurs long before the onset of disease symptoms, and abnormal proteolysis may either play an active role or be a companying event of neuronal injury. Increased spectrin cleavage yielding elevated spectrin breakdown products (SBDPs) by calcium-sensitive proteases such as calpain and caspases has been established in conditions associated with acute neuronal damage such as traumatic brain injury (TBI). Here we review literature regarding spectrin expression and metabolism in the brain, and propose a potential use of SBDPs as biomarkers for neurodegenerative diseases such as Alzheimer's diseases.
Collapse
|
7
|
Silva DF, Selfridge JE, Lu J, Lezi E, Cardoso SM, Swerdlow RH. Mitochondrial abnormalities in Alzheimer's disease: possible targets for therapeutic intervention. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2012; 64:83-126. [PMID: 22840745 PMCID: PMC3625400 DOI: 10.1016/b978-0-12-394816-8.00003-9] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mitochondria from persons with Alzheimer's disease (AD) differ from those of age-matched control subjects. Differences in mitochondrial morphology and function are well documented, and are not brain-limited. Some of these differences are present during all stages of AD, and are even seen in individuals who are without AD symptoms and signs but who have an increased risk of developing AD. This chapter considers the status of mitochondria in AD subjects, the potential basis for AD subject mitochondrial perturbations, and the implications of these perturbations. Data from multiple lines of investigation, including epidemiologic, biochemical, molecular, and cytoplasmic hybrid studies, are reviewed. The possibility that mitochondria could potentially constitute a reasonable AD therapeutic target is discussed, as are several potential mitochondrial medicine treatment strategies.
Collapse
Affiliation(s)
- Diana F. Silva
- Department of Neurology, University of Kansas School of Medicine, Kansas City, Kansas USA
- Centre for Neuroscience and Cell Biology, University of Coimbra, Coimbra Portugal
| | - J. Eva Selfridge
- Department of Molecular and Integrative Physiology, University of Kansas School of Medicine, Kansas City, Kansas USA
| | - Jianghua Lu
- Department of Neurology, University of Kansas School of Medicine, Kansas City, Kansas USA
| | - E Lezi
- Department of Physical Therapy and Rehabilitation Medicine, University of Kansas School of Medicine, Kansas City, Kansas USA
| | - Sandra M. Cardoso
- Centre for Neuroscience and Cell Biology, University of Coimbra, Coimbra Portugal
| | - Russell H. Swerdlow
- Department of Neurology, University of Kansas School of Medicine, Kansas City, Kansas USA
- Department of Molecular and Integrative Physiology, University of Kansas School of Medicine, Kansas City, Kansas USA
- Department of Biochemistry and Molecular Biology, University of Kansas School of Medicine, Kansas City, Kansas USA
| |
Collapse
|
8
|
Bernath E, Kupina N, Liu MC, Hayes RL, Meegan C, Wang KKW. Elevation of cytoskeletal protein breakdown in aged Wistar rat brain. Neurobiol Aging 2006; 27:624-32. [PMID: 15913844 DOI: 10.1016/j.neurobiolaging.2005.02.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2004] [Revised: 02/04/2005] [Accepted: 02/25/2005] [Indexed: 11/24/2022]
Abstract
Previous studies indicated there is an overall increase of proteolysis in aging rat brains. We monitored the potential degradation of cytoskeletal proteins in neuronal tissue taken from cerebral cortex and cerebellum of young (3 month) and aging (17, 21 and 23.5 month) Wistar rats. We found significant age-dependent proteolysis of cytoskeletal proteins (alphaII-spectrin and microtubule-associated protein MAP-2A/B) in the cerebral cortex and the cerebellum. The pattern of alphaII-spectrin breakdown shows a marked increase in 150- and 145-kDa fragments (SBDP150 and SBDP145, respectively), but we did not detect the caspase-3-mediated 120-kDa fragment (SBDP120) in aged rat brains, suggesting the involvement of the calpain proteases. The pattern of MAP-2A/B breakdown in aged rat brains mirrors that produced by in vitro calpain digestion of 3-month control rat brain MAP-2A/B. In aged rat brains, there is no significant increase in pro-caspase-3 processing; rather, there is a moderate reduction in pro-caspase-3 protein and caspase-3 hydrolytic activity in the cortex. These results point to selective susceptibility of cytoskeletal proteins to calpain-mediated degradation, but not caspase-3 in aging rat brains.
Collapse
Affiliation(s)
- Eric Bernath
- Department of Neuroscience, McKnight Brian Institute, L4-100, P.O. Box 100256, University of Florida, Gainesville, FL 32610, USA
| | | | | | | | | | | |
Collapse
|
9
|
|
10
|
Cribbs DH, Poon WW, Rissman RA, Blurton-Jones M. Caspase-mediated degeneration in Alzheimer's disease. THE AMERICAN JOURNAL OF PATHOLOGY 2004; 165:353-5. [PMID: 15277211 PMCID: PMC1618562 DOI: 10.1016/s0002-9440(10)63302-0] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- David H Cribbs
- Institute for Brain Aging and Dementia, Irvine CA 92697-4540, USA.
| | | | | | | |
Collapse
|
11
|
Nakayama J, Yoshizawa T, Yamamoto N, Arinami T. Mutation analysis of the calpastatin gene (CAST) in patients with Alzheimer's disease. Neurosci Lett 2002; 320:77-80. [PMID: 11849768 DOI: 10.1016/s0304-3940(02)00061-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The calpains, a family of calcium-dependent cysteine proteinases, and calpastatin, their endogenous inhibitor protein, are involved in the proteolysis of amyloid precursor protein, which is thought to be abnormal in patients with Alzheimer's disease (AD). Specific inhibitors of calpains attenuate amyloid beta peptide-induced neuronal death. We hypothesized that some AD patients have functionally deficient mutation(s) of the CAST gene encoding calpastatin, and we screened 40 Japanese patients with AD for mutations in the coding region of CAST. Nine polymorphisms, -82A/G, IVS7-96A/G, 669A/G, 1223C/G (Ser408Cys), IVS20-10C/T, IVS21-65G/A, IVS22+31T/C, IVS24+38Ins/DelA, and IVS25-32A/G, were identified. The 669A allele causes skipping of exon 11, leading to the loss of 13 residues. Comparisons between 101 patients and 90 controls revealed no significant association between CAST polymorphisms and risk for AD, indicating that genomic variations of CAST are not likely to be substantially involved in the etiology of AD.
Collapse
Affiliation(s)
- Junko Nakayama
- Department of Medical Genetics, Institute of Basic Medical Sciences, University of Tsukuba, Tsukuba, Ibaraki-ken 305-8575, Japan
| | | | | | | |
Collapse
|
12
|
Rohn TT, Head E, Su JH, Anderson AJ, Bahr BA, Cotman CW, Cribbs DH. Correlation between caspase activation and neurofibrillary tangle formation in Alzheimer's disease. THE AMERICAN JOURNAL OF PATHOLOGY 2001; 158:189-98. [PMID: 11141492 PMCID: PMC1850275 DOI: 10.1016/s0002-9440(10)63957-0] [Citation(s) in RCA: 126] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Although evidence suggests that neurofibrillary tangles (NFTs) and neuronal cell loss are prominent features of Alzheimer's disease (AD), the relationship between the two remains unknown. In the present study, the relationship between the activation of apoptotic mechanisms and NFT formation in AD was investigated using a caspase-cleavage site-directed antibody to fodrin, an abundant neuronal cytoskeleton protein. This antibody recognized cleavage products of fodrin after digestion by caspase-3, but did not recognize full-length fodrin. In vitro analysis of this fodrin caspase-cleavage product (CCP) antibody demonstrates that it is a specific probe for the detection of apoptotic but not necrotic pathways in cultured neurons. To determine whether caspases cleave fodrin in vivo, tissue sections from controls and AD were immunostained for fodrin (CCPs). Although no staining was observed in control cases, labeling of neurons was observed in the hippocampus of all AD cases, which increased as a function of disease progression. To determine a possible relationship between caspase activation and NFT formation, double-labeling experiments with fodrin CCP and PHF-1 were performed. Co-localization of these markers was observed in many neurons, and quantitative analysis showed that as the extent of NFT formation increased, there was a significant corresponding increase in fodrin CCP immunolabeling (r = 0.84). Taken together, these results provide evidence for the activation of apoptotic mechanisms in neurons in the AD brain and suggest that there is an association between NFT formation and the activation of apoptotic pathways in AD.
Collapse
Affiliation(s)
- T T Rohn
- Institute for Brain Aging and Dementia, University of California at Irvine, 92697-4540, USA
| | | | | | | | | | | | | |
Collapse
|
13
|
Vanderklish PW, Bahr BA. The pathogenic activation of calpain: a marker and mediator of cellular toxicity and disease states. Int J Exp Pathol 2000; 81:323-39. [PMID: 11168679 PMCID: PMC2517738 DOI: 10.1111/j.1365-2613.2000.00169.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2000] [Accepted: 08/14/2000] [Indexed: 11/30/2022] Open
Abstract
Over-activation of calpain, a ubiquitous calcium-sensitive protease, has been linked to a variety of degenerative conditions in the brain and several other tissues. Dozens of substrates for calpain have been identified and several of these have been used to measure activation of the protease in the context of experimentally induced and naturally occurring pathologies. Calpain-mediated cleavage of the cytoskeletal protein spectrin, in particular, results in a set of large breakdown products (BDPs) that are unique in that they are unusually stable. Over the last 15 years, measurements of BDPs in experimental models of stroke-type excitotoxicity, hypoxia/ischemia, vasospasm, epilepsy, toxin exposure, brain injury, kidney malfunction, and genetic defects, have established that calpain activation is an early and causal event in the degeneration that ensues from acute, definable insults. The BDPs also have been found to increase with normal ageing and in patients with Alzheimer's disease, and the calpain activity may be involved in related apoptotic processes in conjunction with the caspase family of proteases. Thus, it has become increasingly clear that regardless of the mode of disturbance in calcium homeostasis or the cell type involved, calpain is critical to the development of pathology and therefore a distinct and powerful therapeutic target. The recent development of antibodies that recognize the site at which spectrin is cleaved has greatly facilitated the temporal and spatial resolution of calpain activation in situ. Accordingly, sensitive spectrin breakdown assays now are utilized to identify potential toxic side-effects of compounds and to develop calpain inhibitors for a wide range of indications including stroke, cerebral vasospasm, and kidney failure.
Collapse
Affiliation(s)
- P W Vanderklish
- Department of Neurobiology, Scripps Research Institute, La Jolla, California, USA
| | | |
Collapse
|
14
|
Etcheberrigaray R, Bhagavan S. Ionic and signal transduction alterations in Alzheimer's disease: relevance of studies on peripheral cells. Mol Neurobiol 1999; 20:93-109. [PMID: 10966116 DOI: 10.1007/bf02742436] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Several lines of evidence indicate that Alzheimer's disease (AD) has systemic expression. Systemic changes are manifested as alterations in a number of molecular and cellular processes. Although, these alterations appear to have little or no consequence in peripheral systems, their parallel expression in the central nervous system (CNS) could account for the principal clinical manifestations of the disease. Recent research seems to indicate that alterations in ion channels, calcium homeostasis, and protein kinase C (PKC) can be linked and thereby constitute a model of pathophysiological relevance. Considering the difficulties of studying dynamic pathophysiological processes in the disease-ridden postmortem AD brain, peripheral tissues such as fibroblasts provide a suitable model to study molecular and cellular aspects of the disease.
Collapse
Affiliation(s)
- R Etcheberrigaray
- Laboratory of Applied Neuroscience, Institute for Cognitive and Computational Sciences, Georgetown University Medical Center, Washington, DC, USA.
| | | |
Collapse
|
15
|
Grynspan F, Griffin WR, Cataldo A, Katayama S, Nixon RA. Active site-directed antibodies identify calpain II as an early-appearing and pervasive component of neurofibrillary pathology in Alzheimer's disease. Brain Res 1997; 763:145-58. [PMID: 9296555 DOI: 10.1016/s0006-8993(97)00384-3] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Calpain proteases influence intracellular signaling pathways and regulate cytoskeleton organization, but the neuronal and pathological roles of individual isoenzymes are unknown. In Alzheimer's disease (AD), the activated form of calpain I is significantly increased while the fate of calpain II has been more difficult to address. Here, calpain II antibodies raised to different sequences within a cryptic region around the active site, which becomes exposed during protease activation, were shown immunohistochemically to bind extensively to neurofibrillary tangles (NFT), neuritic plaques, and neuropil threads in brains from individuals with AD. Additional 'pre-tangle' granular structures in neurons were also intensely immunostained, indicating calpain II mobilization at very early stages of NFT formation. Total levels of calpain II remained constant in the prefrontal cortex of AD patients but were increased 8-fold in purified NFT relative to levels of calpain I. These results implicate activated calpain II in neurofibrillary degeneration, provide further evidence for the involvement of the calpain system in AD pathogenesis, and imply that neuronal calcium homeostasis is altered in AD.
Collapse
Affiliation(s)
- F Grynspan
- Laboratories of Molecular Neuroscience, Mailman Research Center, McLean Hospital, Belmont, MA 02178, USA
| | | | | | | | | |
Collapse
|
16
|
Fernández-Shaw C, Marina A, Cazorla P, Valdivieso F, Vázquez J. Anti-brain spectrin immunoreactivity in Alzheimer's disease: degradation of spectrin in an animal model of cholinergic degeneration. J Neuroimmunol 1997; 77:91-8. [PMID: 9209273 DOI: 10.1016/s0165-5728(97)00066-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
In a previous work, we described the existence of anti-brain spectrin auto antibodies in Alzheimer's disease (AD) patients (J. Neuroimmunol. 68 (1996) 39-44). In this report, we further support our previous observations, showing that sera from 9 out of 18 AD patients, but none of 14 control subjects, immunoreacted with spectrin synthesized by PC12 cells. In addition, degradation of brain spectrin was found to be greatly enhanced in the frontal cortex of rats subjected to an animal model of cholinergic degeneration. Our data suggest that spectrin degradation and generation of anti-spectrin auto antibodies may be related to the cholinergic degeneration encountered in AD.
Collapse
Affiliation(s)
- C Fernández-Shaw
- Centro de Biología Molecular Severo Ochod, Universidad Autónoma de Madrid, Spain
| | | | | | | | | |
Collapse
|
17
|
Guttmann RP, Elce JS, Bell PD, Isbell JC, Johnson GV. Oxidation inhibits substrate proteolysis by calpain I but not autolysis. J Biol Chem 1997; 272:2005-12. [PMID: 8999893 DOI: 10.1074/jbc.272.3.2005] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
In this study, the effects of oxidation on calpain I autolysis and calpain-mediated proteolysis were examined. Calpain I was incubated with increasing concentrations of free calcium in the presence or absence of oxidant, and autolytic conversion of both the 80- and 30-kDa subunits was measured by immunoblotting utilizing monoclonal antibodies which recognize both autolyzed and non-autolyzed forms of each subunit, respectively. Autolytic conversion of the 80-kDa subunit of calpain I was not detected until free calcium concentration was greater than 40 microM, whereas autolysis of the 30-kDa subunit did not occur until the free calcium concentration was greater than 100 microM. In addition, autolytic conversion of either the 80- or 30-kDa subunit was not inhibited by the presence of oxidant. Calpain I activity was measured using the fluorescent peptide N-succinyl-L-leucyl-L-leucyl-L-valyl-L-tyrosine-7-amido-4- methylcoumarin or the microtubule-associated protein tau as substrate. Calpain I was found to have proteolytic activity at free calcium concentrations below that required for autolysis. Calpain I activity was strongly inhibited by oxidant at all calcium concentrations studied, suggesting that proteolytic activity of both the non-autolyzed 80-kDa and autolyzed 76-kDa forms was susceptible to oxidation. Interestingly, whereas oxidation did not inhibit autolytic conversion, the presence of high substrate concentrations did result in a significant reduction of autolysis without altering calpain proteolytic activity. Calpain I activity that had been inhibited by the presence of oxidant was recovered immediately by addition of the reducing agent dithiothreitol.
Collapse
Affiliation(s)
- R P Guttmann
- Department of Psychiatry, University of Alabama at Birmingham, Birmingham, Alabama 35294-0017, USA
| | | | | | | | | |
Collapse
|
18
|
Vázquez J, Fernández-Shaw C, Marina A, Haas C, Cacabelos R, Valdivieso F. Antibodies to human brain spectrin in Alzheimer's disease. J Neuroimmunol 1996; 68:39-44. [PMID: 8784258 DOI: 10.1016/0165-5728(96)00065-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We investigated the existence of antibodies in sera of Alzheimer's disease patients which immunoreact with specific antigens from crude human brain extracts. We found that 49% of patients, per only 5% of control subjects, had increased levels of antibodies to a 240 kDa protein. On the basis of immunological criteria and internal amino acid sequencing, this antigen was identified as brain spectrin, a cytoskeletal protein which appears to be implicated in synaptic plasticity. Our data raises the possibility that anti-spectrin antibodies could be implicated in Alzheimer's disease pathogenesis.
Collapse
Affiliation(s)
- J Vázquez
- Centro de Biología Molecular Severo Ochod Universidad Autónoma de Madrid, Cantoblanco, Spain.
| | | | | | | | | | | |
Collapse
|
19
|
Gibson G, Martins R, Blass J, Gandy S. Altered oxidation and signal transduction systems in fibroblasts from Alzheimer patients. Life Sci 1996; 59:477-89. [PMID: 8761336 DOI: 10.1016/0024-3205(96)00327-x] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Abnormalities in calcium regulation, amyloid-beta-protein (A beta) production and oxidative metabolism have been implicated in Alzheimer's disease (AD). The use of cultured fibroblasts complement post-mortem and genetic approaches in clarifying the interaction of these processes and the underlying mechanism for the changes in AD. Definition of gene defects in particular Alzheimer families (FAD) permits elucidation of the role of those genetic abnormalities in altered signal transduction in cell lines from those families. Abnormalities in calcium regulation, ion channels, cyclic AMP, the phosphatidylinositide cascade and oxidative metabolism are well documented in fibroblasts from patients with primary genetic defects in the presenilins. Recent studies in AD fibroblasts that demonstrate abnormal secretion of A beta, a protein known to form the characteristic extracellular amyloid deposits in AD brain, further supports the use of these cells in AD research. Comparison of changes in calcium signaling, mitochondrial oxidation and A beta production in these cells suggests that changes in signal transduction including calcium may be a more consistent observation than altered A beta production in fibroblasts from some FAD families. An understanding of these abnormalities in fibroblasts may provide further insights into the pathophysiology of AD, new diagnostic measures and perhaps innovative therapeutic approaches.
Collapse
Affiliation(s)
- G Gibson
- Cornell University Medical College, Burke Medical Research Institute, White Plains, NY 10605, USA
| | | | | | | |
Collapse
|
20
|
Karlsson JO, Blennow K, Janson I, Blomgren K, Karlsson I, Regland B, Wallin A, Gottfries CG. Increased proteolytic activity in lymphocytes from patients with early onset Alzheimer's disease. Neurobiol Aging 1995; 16:901-6. [PMID: 8622780 DOI: 10.1016/0197-4580(95)02004-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The levels of calpains (m-calpain and mu-calpain) in peripheral blood lymphocytes from patients with Alzheimer's disease were determined via Western blotting. The Ca-dependent proteolytic activity and the calpastatin activity were estimated using incubation with exogenous substrate. Evidence was obtained for an increased Ca-dependent proteolytic activity in lymphocytes from patients with early onset Alzheimer's disease. There was also an increased level of membrane-bound mu-calpain in this group of patients. The observed changes may be caused by a general dysregulation of Ca homeostasis in peripheral cells of early onset Alzheimer victims.
Collapse
Affiliation(s)
- J O Karlsson
- Department of Anatomy and Cell Biology, Göteborg University, Sweden
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Li QX, Evin G, Small DH, Multhaup G, Beyreuther K, Masters CL. Proteolytic processing of Alzheimer's disease beta A4 amyloid precursor protein in human platelets. J Biol Chem 1995; 270:14140-7. [PMID: 7775475 DOI: 10.1074/jbc.270.23.14140] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The processing of amyloid precursor protein (APP) and production of beta A4 amyloid are events likely to influence the development and progression of Alzheimer's disease, since beta A4 is the major constituent of amyloid deposited in this disorder. Our previous studies showed that human platelets contain full-length APP (APPFL) and are a suitable substrate to study normal APP processing. In the present study, we show that a 22-kDa beta A4-containing carboxyl-terminal fragment (22-CTF) of APP is present in unstimulated platelets. Both APPFL and 22-CTF are proteolytically degraded when platelets are activated with thrombin, collagen, or calcium ionophore A23187. Complete cleavage of APPFL and 22-CTF require the presence of extracellular calcium. Following stimulation in the presence of calcium, a new CTF of 17 kDa is generated, and the NH2-terminal epitope of beta A4 amyloid is lost. Preincubation of platelets with the cell-permeable cysteine protease inhibitors calpeptin, (2S,3S)-trans-epoxysuccinyl-L-leucyl-amido-3-methylbutane ethyl ester (E64d), Na alpha-p-tosyl-L-lysine chloromethyl ketone, or calcium chelator EGTA before platelet stimulation inhibits the degradation of both APPFL and 22-CTF. Divalent metal ions including zinc, copper, and cobalt inhibit the degradation of APPFL and 22-CTF. This study suggests that a calcium-dependent neutral cysteine protease is involved in the proteolytic processing of an amyloidogenic species of APP in human platelets.
Collapse
Affiliation(s)
- Q X Li
- Department of Pathology, University of Melbourne, Parkville, Victoria, Australia
| | | | | | | | | | | |
Collapse
|
22
|
Huang HM, Martins R, Gandy S, Etcheberrigaray R, Ito E, Alkon DL, Blass J, Gibson G. Use of cultured fibroblasts in elucidating the pathophysiology and diagnosis of Alzheimer's disease. Ann N Y Acad Sci 1994; 747:225-44. [PMID: 7847673 DOI: 10.1111/j.1749-6632.1994.tb44412.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- H M Huang
- Cornell University Medical College, Department of Neurology and Neuroscience, Burke Medical Research Institute, White Plains, New York 10605
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Nixon RA, Saito KI, Grynspan F, Griffin WR, Katayama S, Honda T, Mohan PS, Shea TB, Beermann M. Calcium-activated neutral proteinase (calpain) system in aging and Alzheimer's disease. Ann N Y Acad Sci 1994; 747:77-91. [PMID: 7847693 DOI: 10.1111/j.1749-6632.1994.tb44402.x] [Citation(s) in RCA: 207] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Calpains (CANPs) are a family of calcium-dependent cysteine proteases under complex cellular regulation. By making selective limited proteolytic cleavages, they activate or alter the regulation of certain enzymes, including key protein kinases and phosphatases, and induce specific cytoskeletal rearrangements, accounting for their suspected involvement in intracellular signaling, vesicular trafficking, and structural stabilization. Calpain activity has been implicated in various aging phenomena, including cataract formation and erythrocyte senescence. Abnormal activation of the large stores of latent calpain in neurons induces cell injury and is believed to underlie neurodegeneration in excitotoxicity, Wallerian degeneration, and certain other neuropathologic states involving abnormal calcium influx. In Alzheimer's disease, we found the ratio of activated calpain I to its latent precursor isoform in neocortex to be threefold higher than that in normal individuals and those with Huntington's or Parkinson's disease. Immunoreactivity toward calpastatin, the endogenous inhibitor of calpain, was also markedly reduced in layers II-V of the neocortex in Alzheimer's disease. The excessive calpain system activation suggested by these findings represents a potential molecular basis for synaptic loss and neuronal cell death in the brain in Alzheimer's disease given the known destructive actions of calpain I and its preferential neuronal and synaptic localization. In surviving cells, persistent calpain activation may also contribute to neurofibrillary pathology and abnormal amyloid precursor protein trafficking/processing through its known actions on protein kinases and the membrane skeleton. The degree of abnormal calpain activation in the brain in Alzheimer's disease strongly correlated with the extent of decline in levels of secreted amyloid precursor protein in brain. Cytoskeletal proteins that are normally good calpain substrates become relatively calpain resistant when they are hyperphosphorylated, which may contribute to their accumulation in neurofibrillary tangles. As a major effector of calcium signals, calpain activity may mirror disturbances in calcium homeostasis and mediate important pathologic consequences of such disturbances.
Collapse
Affiliation(s)
- R A Nixon
- Laboratories for Molecular Neuroscience, McLean Hospital, Belmont, Massachusetts 02178
| | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Hensley K, Carney J, Hall N, Shaw W, Butterfield DA. Electron paramagnetic resonance investigations of free radical-induced alterations in neocortical synaptosomal membrane protein infrastructure. Free Radic Biol Med 1994; 17:321-31. [PMID: 8001836 DOI: 10.1016/0891-5849(94)90018-3] [Citation(s) in RCA: 78] [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: 01/28/2023]
Abstract
Evidence is presented that free radical stress can directly induce physico-chemical alterations in rodent neocortical synaptosomal membrane proteins. Synaptosomes were prepared from gerbil cortical brain tissue and incubated with 3 mM ascorbate and various concentrations of exogenous Fe2+ for 30-240 min at 37 degrees C. Synaptosomes were then lysed and covalently labeled with the protein thiol-selective spin label MAL-6 (2,2,6,6-tetramethyl-4-maleimidopiperdin-1-oxyl) and subjected to electron paramagnetic resonance (EPR) spectrometry. In separate experiments, synaptosomal membranes were labeled with the thiol-specific spin label MTS ((1-oxyl-2,2,5,5-tetramethyl-pyrroline-3-methyl)-methanethiosulfonate), or the lipid-specific spin probe 5-NS (5-nitroxide stearate). Free radical stress induced by iron/ascorbate treatment has a rigidizing effect on the protein infrastructure of these membranes, as appraised by EPR analysis of membrane protein-bound spin label, but no change was detected in the lipid component of the membrane. These results are discussed with reference to potential oxidative mechanisms in aging and neurological disorders.
Collapse
Affiliation(s)
- K Hensley
- Department of Chemistry, University of Kentucky, Lexington 40506
| | | | | | | | | |
Collapse
|
25
|
Elliott EM, Mattson MP, Vanderklish P, Lynch G, Chang I, Sapolsky RM. Corticosterone exacerbates kainate-induced alterations in hippocampal tau immunoreactivity and spectrin proteolysis in vivo. J Neurochem 1993; 61:57-67. [PMID: 8515288 DOI: 10.1111/j.1471-4159.1993.tb03537.x] [Citation(s) in RCA: 83] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Aberrant elevations in intracellular calcium levels, promoted by the excitatory amino acid glutamate, may be a final common mediator of the neuronal damage that occurs in hypoxic-ischemic and seizure disorders. Glutamate and altered neuronal calcium homeostasis have also been proposed to play roles in more chronic neurodegenerative disorders, including Alzheimer's disease. Any extrinsic factors that may augment calcium levels during such disorders may significantly exacerbate the resulting damage. Glucocorticoids (GCs), the adrenal steroid hormones released during stress, may represent one such extrinsic factor. GCs can exacerbate hippocampal damage induced by excitotoxic seizures and hypoxia-ischemia, and we have observed recently that GCs elevate intracellular calcium levels in hippocampal neurons. We now report that the excitotoxin kainic acid (KA) can elicit antigenic changes in the microtubule-associated protein tau similar to those seen in the neurofibrillary tangles of Alzheimer's disease. KA induced a transient increase in the immunoreactivity of hippocampal CA3 neurons towards antibodies that recognize aberrant forms of tau (5E2 and Alz-50). The tau immunoreactivity appeared within 3 h of KA injection, preceded extensive neuronal damage, and subsequently disappeared as neurons degenerated. KA also caused spectrin breakdown, indicating the involvement of calcium-dependent proteases. Physiological concentrations of corticosterone (the species-typical GC of rats) enhanced the neuronal damage induced by KA and, critically, enhanced the intensity of tau immunoreactivity and spectrin breakdown. Moreover, the GC enhancement of spectrin proteolysis was prevented by energy supplementation, supporting the hypothesis that GC disruption of calcium homeostasis in the hippocampus is energetic in nature. Taken together, these findings demonstrate that neurofibrillary tangle-like alterations in tau, and spectrin breakdown, can be induced by excitatory amino acids and exacerbated by GCs in vivo.
Collapse
Affiliation(s)
- E M Elliott
- Department of Biological Sciences, Stanford University, California
| | | | | | | | | | | |
Collapse
|
26
|
Saito K, Elce JS, Hamos JE, Nixon RA. Widespread activation of calcium-activated neutral proteinase (calpain) in the brain in Alzheimer disease: a potential molecular basis for neuronal degeneration. Proc Natl Acad Sci U S A 1993; 90:2628-32. [PMID: 8464868 PMCID: PMC46148 DOI: 10.1073/pnas.90.7.2628] [Citation(s) in RCA: 446] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Calcium-activated neutral proteinases (CANPs or calpains) are believed to be key enzymes in intracellular signaling cascades and potential mediators of calcium-induced neuronal degeneration. To investigate their involvement in Alzheimer disease, we identified three isoforms of muCANP (calpain I) in human postmortem brain corresponding to an 80-kDa precursor and two autolytically activated isoforms (78 and 76 kDa). As an index of changes in the in vivo activity of muCANP in Alzheimer disease, the ratio of the 76-kDa activated isoform of muCANP to its 80-kDa precursor was measured by immunoassay in selected brain regions from 22 individuals with Alzheimer disease and 18 normal controls. This muCANP activation ratio was elevated 3-fold in the prefrontal cortex from patients with Alzheimer disease but not from patients with Huntington disease. The activation ratio was also significantly elevated, but to a lesser degree, in brain regions where Alzheimer pathology is milder and has not led to overt neuronal degeneration. These findings indicate that muCANP activation is not simply a consequence of cellular degeneration but may be associated with dysfunction in many neurons before gross structural changes occur. The known influences of CANPs on cytoskeleton and membrane dynamics imply that persistent CANP activation may contribute to neurofibrillary pathology and abnormal amyloid precursor protein processing prior to causing synapse loss or cell death in the most vulnerable neuronal populations. Pharmacological modulation of the CANP system may merit consideration as a potential therapeutic strategy in Alzheimer disease.
Collapse
Affiliation(s)
- K Saito
- McLean Hospital, Belmont, MA 02178
| | | | | | | |
Collapse
|
27
|
Affiliation(s)
- R B Scott
- Department of Medicine, Medical College of Virginia/Virginia Commonwealth University, Richmond 23298-0214
| |
Collapse
|
28
|
Hensley K, Postlewaite J, Dobbs P, Butterfield DA. Alteration of the erythrocyte membrane via enzymatic degradation of ankyrin (band 2.1): subcellular surgery characterized by EPR spectroscopy. BIOCHIMICA ET BIOPHYSICA ACTA 1993; 1145:205-11. [PMID: 8381664 DOI: 10.1016/0005-2736(93)90290-g] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
A fraction of band 3 protein, the major transmembrane protein of erythrocyte membranes, is held to the cytoskeletal protein spectrin via noncovalent interactions with the protein ankyrin (band 2.1). In this study, trypsin was used under defined conditions to selectively proteolyze ankyrin and thereby destroy the band 3-ankyrin linkage on the cytoplasmic side of erythrocyte ghost membranes. Electron paramagnetic resonance (EPR) spectroscopy, in conjunction with selective spin labeling methods, was used to monitor conformational changes occurring in cytoskeletal proteins or cell-surface carbohydrates as a result of this treatment. Treatment of RBC ghosts with TPCK-trypsin for 5 s at 0 degrees C caused an approx. 56% increase in the relevant EPR parameter of a maleimide spin label bound to spectrin (P < 0.004), indicative of increased segmental motion of the spin label and decreased protein-protein interactions. Analysis of the apparent rotational correlation time parameter tau of a spin label covalently and selectively bound to terminal sialic acid residues of glycophorin showed no significant effect from trypsin treatment. However, tau of spin label covalently and specifically bound to terminal galactose residues of cell-surface glycoconjugates of band 3 and other transmembrane glycoproteins significantly decreased with tryptic uncoupling of the ankyrin linkage (P < 0.005). These results suggest a marked conformational alteration in both cytoskeletal and transmembrane proteins as a result of uncoupling from ankyrin. Spermine (N,N'-bis(3-aminopropyl)tetramethylenediamine), a naturally occurring polyamine known to strengthen cytoskeletal protein-protein interactions (Wyse and Butterfield (1988) Biochim. Biophys. Acta 941, 141-149), was used to partially reverse the trypsin-induced cytoskeletal alterations. Addition of 2 mM spermine to ghosts previously treated with trypsin increased cytoskeletal protein-protein interactions as indicated by EPR (P < 0.002). SDS-PAGE was used to confirm the integrity of spectrin, band 3, and band 4.1 in all experiments. The results are discussed with reference to transmembrane signaling mechanisms and membrane-associated pathologies.
Collapse
Affiliation(s)
- K Hensley
- Department of Chemistry, University of Kentucky, Lexington 40506-0055
| | | | | | | |
Collapse
|
29
|
Abstract
Alterations in calcium transport appear to be functionally significant. Treatment with drugs that promote calcium uptake partially reverse some of the age-related deficits in calcium-dependent processes. Thus, the relevance of decreased calcium coupled receptor binding is supported by the ability of 3,4-diaminopyridine to promote acetylcholine release by forebrain slices from aged mice. This drug also reduces the age-related depression in synaptosomal calcium uptake in aged rats and mice. 3,4-Diaminopyridine also reverses the age-related deficit in calcium transport, the age-related deficits in the tight rope test, and 8 arm maze performance. 3,4-Diaminopyridine is also effective in nonexcitable tissues, such as cultured skin fibroblasts; it increases the decreased cytosolic-free calcium. Depressed cell spreading of fibroblasts can be reversed by treatment of cells with the calcium ionophore A23187 which promotes calcium influx. 4-Aminopyridine, a similarly related compound, partially reverses short-term memory deficits in patients with Alzheimer's disease. Tetrahydroaminoacridine, an aminopyridine analog with anticholinesterase properties, produces clinical improvement in behavioral deficits due to Alzheimer's disease. Only recently has the aging brain become a subject of intense study. Evidently, the neurobiology of aging needs to develop its own theories to account for the unique aspects of brain aging as well as integrate them with the peripheral changes. An exciting but unexplored area of research in the aging brain concerns the coupling between calcium and the final end product, the induction of genes. Still unknown are the molecular events that set these processes in motion. In addition, whether conditions such as dietary restriction that increase longevity in certain rodents also retard age-related changes in calcium remains to be determined.
Collapse
Affiliation(s)
- C Peterson
- Division of Neurobiology, University of Southern California, Los Angeles 90089-0191
| |
Collapse
|
30
|
Abstract
Calcium binding to brain and erythrocyte spectrins was studied at physiological ionic strength by a calcium overlay assay and aqueous two-phase partitioning. When the spectrins were immobilized on nylon membranes by slot blotting, the overlay assay showed that even though both spectrins bound 45Ca2+, the brain protein displayed much greater affinity for calcium ions than erythrocyte spectrin did. Since the observed binding was weaker than that displayed by calmodulin under similar conditions, the overlay assay results indicated that the binding must be weaker than 1 microM. The phase partition experiments showed that there are at least two sites for calcium on brain spectrin and that calcium binding to one of these sites is reduced significantly by magnesium ions. From the partition isotherm, the dissociation constants were estimated as 50 microM for the Mg(2+)-independent site and 150 microM for the Mg(2+)-dependent site. The phase partition results also showed that erythrocyte spectrin bound calcium ions at least 1 order of magnitude weaker. By examining calcium binding to slot-blotted synthetic peptides, we identified two binding sites in brain spectrin. One mapped to the second putative calcium binding site (EF-hand) in alpha-spectrin and the other to the 36 amino acid residue long insert in domain 11. In addition, a tryptic fragment derived from the C-terminal of erythrocyte alpha-spectrin, which contained the two postulated EF-hands, also bound calcium. These findings suggest that the calcium signal system may also involve direct binding of calcium to spectrin beside known calcium modulators such as calmodulin and calpain.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- S Lundberg
- Department of Biochemistry, University of Umeå, Sweden
| | | | | |
Collapse
|
31
|
Bahr BA, Vanderklish PW, Ha LT, Tin MT, Lynch G. Spectrin breakdown products increase with age in telencephalon of mouse brain. Neurosci Lett 1991; 131:237-40. [PMID: 1762696 DOI: 10.1016/0304-3940(91)90622-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Calcium activated proteolysis of brain spectrin produces characteristic breakdown products (BDPs), the concentrations of which increase markedly in many instances of brain pathology. Results reported here indicate that levels of the BDPs rise with age (3-30 months) in the telencephalon but not in the hindbrain of Balb/c mice. These observations suggest that spectrin breakdown is a pathologic biochemical marker which increases with age in some but not all brain regions.
Collapse
Affiliation(s)
- B A Bahr
- Center for Neurobiology of Learning and Memory, University of California, Irvine 92717-3800
| | | | | | | | | |
Collapse
|