1
|
Chondroitin sulfate E alleviates β-amyloid toxicity in transgenic Caenorhabditis elegans by inhibiting its aggregation. Int J Biol Macromol 2022; 209:1280-1287. [PMID: 35461860 DOI: 10.1016/j.ijbiomac.2022.04.124] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 04/14/2022] [Accepted: 04/17/2022] [Indexed: 01/13/2023]
Abstract
Chondroitin sulfate E (CS-E), which is characterized by oversulfated disaccharide units, has been shown to regulate neuronal adhesion, neurite outgrowth and exert neuroprotective effects. In view of these findings, here we investigated the anti-Alzheimer's disease (AD) activities of CSE by using transgenic Caenorhabditis elegans model of Alzheimer's disease. The behavioral experiments demonstrated that CSE at the concentration of 1 mg/ml significantly delayed the worm paralysis caused by Aβ aggregation as compared with control group. Western blot analysis revealed that the level of small oligomers in the transgenic C. elegans was significantly reduced upon treatment with CSE. The number of Aβ plaque deposits in transgenic worm was significantly decreased. In addition, CSE also protected the worms from oxidative stress and rescued chemotaxis dysfunction in transgenic strain CL2355. Taken together, these data suggested that CSE could protect against Aβ-induced toxicity in C. elegans. These results offer valuable evidence for the future use of CSE in the development of agents for the treatment of AD.
Collapse
|
2
|
Petit N, Dyer JM, Clerens S, Gerrard JA, Domigan LJ. Oral delivery of self-assembling bioactive peptides to target gastrointestinal tract disease. Food Funct 2021; 11:9468-9488. [PMID: 33155590 DOI: 10.1039/d0fo01801e] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Peptides are known for their diverse bioactivities including antioxidant, antimicrobial, and anticancer activity, all three of which are potentially useful in treating colon-associated diseases. Beside their capability to stimulate positive health effects once released in the body, peptides are able to form useful nanostructures such as hydrogels. Combining peptide bioactivity and peptide gel-forming potentials can create interesting systems that can be used for oral delivery. This combination, acting as a two-in-one system, has the potential to avoid the need for delicate entrapment of a drug or natural bioactive compound. We here review the context and research progress, to date, in this area.
Collapse
Affiliation(s)
- Noémie Petit
- Riddet Institute, Massey University, PB 11 222, Palmerston North 4442, New Zealand
| | | | | | | | | |
Collapse
|
3
|
Campora M, Francesconi V, Schenone S, Tasso B, Tonelli M. Journey on Naphthoquinone and Anthraquinone Derivatives: New Insights in Alzheimer's Disease. Pharmaceuticals (Basel) 2021; 14:33. [PMID: 33466332 PMCID: PMC7824805 DOI: 10.3390/ph14010033] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Revised: 12/27/2020] [Accepted: 12/30/2020] [Indexed: 12/11/2022] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disease that is characterized by memory loss, cognitive impairment, and functional decline leading to dementia and death. AD imposes neuronal death by the intricate interplay of different neurochemical factors, which continue to inspire the medicinal chemist as molecular targets for the development of new agents for the treatment of AD with diverse mechanisms of action, but also depict a more complex AD scenario. Within the wide variety of reported molecules, this review summarizes and offers a global overview of recent advancements on naphthoquinone (NQ) and anthraquinone (AQ) derivatives whose more relevant chemical features and structure-activity relationship studies will be discussed with a view to providing the perspective for the design of viable drugs for the treatment of AD. In particular, cholinesterases (ChEs), β-amyloid (Aβ) and tau proteins have been identified as key targets of these classes of compounds, where the NQ or AQ scaffold may contribute to the biological effect against AD as main unit or significant substructure. The multitarget directed ligand (MTDL) strategy will be described, as a chance for these molecules to exhibit significant potential on the road to therapeutics for AD.
Collapse
Affiliation(s)
| | | | | | | | - Michele Tonelli
- Dipartimento di Farmacia, Università degli Studi di Genova, Viale Benedetto XV, 3, 16132 Genova, Italy; (M.C.); (V.F.); (S.S.); (B.T.)
| |
Collapse
|
4
|
Xu C, Xiao Z, Wu H, Zhou G, He D, Chang Y, Li Y, Wang G, Xie M. BDMC protects AD in vitro via AMPK and SIRT1. Transl Neurosci 2020; 11:319-327. [PMID: 33335771 PMCID: PMC7712110 DOI: 10.1515/tnsci-2020-0140] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 08/04/2020] [Accepted: 08/13/2020] [Indexed: 01/02/2023] Open
Abstract
Background Alzheimer’s disease (AD) is a common neurodegenerative disorder without any satisfactory therapeutic approaches. AD is mainly characterized by the deposition of β-amyloid protein (Aβ) and extensive neuronal cell death. Curcumin, with anti-oxidative stress (OS) and cell apoptosis properties, plays essential roles in AD. However, whether bisdemethoxycurcumin (BDMC), a derivative of curcumin, can exert a neuroprotective effect in AD remains to be elucidated. Methods In this study, SK-N-SH cells were used to establish an in vitro model to investigate the effects of BDMC on the Aβ1–42-induced neurotoxicity. SK-N-SH cells were pretreated with BDMC and with or without compound C and EX527 for 30 min after co-incubation with rotenone for 24 h. Subsequently, western blotting, cell viability assay and SOD and GSH activity measurement were performed. Results BDMC increased the cell survival, anti-OS ability, AMPK phosphorylation levels and SIRT1 in SK-N-SH cells treated with Aβ1–42. However, after treatment with compound C, an AMPK inhibitor, and EX527, an SIRT1inhibitor, the neuroprotective roles of BDMC on SK-N-SH cells treated with Aβ1–42 were inhibited. Conclusion These results suggest that BDMC exerts a neuroprotective role on SK-N-SH cells in vitro via AMPK/SIRT1 signaling, laying the foundation for the application of BDMC in the treatment of neurodegenerative diseases related to AMPK/SIRT1 signaling.
Collapse
Affiliation(s)
- Chenlin Xu
- The First Affiliated Hospital, University of South China, Hengyang, Hunan 421001, People's Republic of China.,Xiangxi Autonomous Prefecture People's Hospital, Jishou, Hunan 416000, People's Republic of China
| | - Zijian Xiao
- The First Affiliated Hospital, University of South China, Hengyang, Hunan 421001, People's Republic of China
| | - Heng Wu
- The First Affiliated Hospital, University of South China, Hengyang, Hunan 421001, People's Republic of China
| | - Guijuan Zhou
- The First Affiliated Hospital, University of South China, Hengyang, Hunan 421001, People's Republic of China
| | - Duanqun He
- The First Affiliated Hospital, University of South China, Hengyang, Hunan 421001, People's Republic of China
| | - Yunqian Chang
- The First Affiliated Hospital, University of South China, Hengyang, Hunan 421001, People's Republic of China
| | - Yihui Li
- The First Affiliated Hospital, University of South China, Hengyang, Hunan 421001, People's Republic of China
| | - Gang Wang
- Department of Rehabilitation, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, People's Republic of China
| | - Ming Xie
- The First Affiliated Hospital, University of South China, Hengyang, Hunan 421001, People's Republic of China
| |
Collapse
|
5
|
Xu F, Zhang X, Wang J, Li X, He B, Xiao F, Yan T, Wu B, Jia Y, Wang Z. Spinosin protects N2a cells from H 2 O 2 -induced neurotoxicity through inactivation of p38MAPK. J Pharm Pharmacol 2020; 72:1607-1614. [PMID: 32667705 DOI: 10.1111/jphp.13334] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 06/14/2020] [Accepted: 06/21/2020] [Indexed: 01/26/2023]
Abstract
OBJECTIVES Previous studies have suggested that spinosin (SPI) exerted neuroprotective effects through inhibition of oxidative damage, but the underlying mechanisms are still unclear. Herein, the mechanisms underlying the protective effects of SPI against oxidative stress induced by hydrogen peroxide (H2 O2 ) were examined in neuro-2a (N2a) mouse neuroblastoma cells. METHODS N2a cells were pretreated with H2 O2 for 2 h, followed by a 24-h incubation with SPI. Intracellular reactive oxygen species (ROS) production was analysed by flow cytometry. Levels of Aβ1-42 production were determined by ELISA assay. Levels of expression of c-Jun N-terminal kinase (JNK), p-JNK, extracellular signal-regulated kinase (ERK), p-ERK, p38 mitogen-activated protein kinase (p38MAPK), p-p38MAPK, p-Tau (Ser199), p-Tau (Ser202), p-Tau (Ser396), synaptophysin (SYP) and postsynaptic scaffold postsynaptic density-95 (PSD-95) were detected by Western blot analysis. KEY FINDINGS Our results showed that H2 O2 treatment enhanced intracellular ROS production in N2a cells. SPI prevented H2 O2 -induced oxidative damage via inhibiting Aβ1-42 production, decreasing Tau phosphorylation and improving synaptic structural plasticity. Notably, H2 O2 -increased p38MAPK activation was attenuated by SPI administration, and p38MAPK inhibitor BIRB796 markedly reduced H2 O2 -induced oxidative damage in N2a cells. CONCLUSIONS Our findings suggest that SPI protects N2a cells from H2 O2 -induced oxidative damage through inactivation of p38MAPK.
Collapse
Affiliation(s)
- Fanxing Xu
- Jiangsu Kanion Pharmaceutical Co., Ltd., Lianyungang, China.,Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang, China.,State Key Laboratory of New-tech for Chinese Medicine Pharmaceutical Process, Lianyungang, China
| | - Xiaoying Zhang
- School of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University, Shenyang, China
| | - Jinyu Wang
- School of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University, Shenyang, China
| | - Xu Li
- Jiangsu Kanion Pharmaceutical Co., Ltd., Lianyungang, China.,State Key Laboratory of New-tech for Chinese Medicine Pharmaceutical Process, Lianyungang, China
| | - Bosai He
- Faculty of Functional Food and Wine, Shenyang Pharmaceutical University, Shenyang, China
| | - Feng Xiao
- Faculty of Functional Food and Wine, Shenyang Pharmaceutical University, Shenyang, China
| | - Tingxu Yan
- Faculty of Functional Food and Wine, Shenyang Pharmaceutical University, Shenyang, China
| | - Bo Wu
- Faculty of Functional Food and Wine, Shenyang Pharmaceutical University, Shenyang, China
| | - Ying Jia
- Faculty of Functional Food and Wine, Shenyang Pharmaceutical University, Shenyang, China
| | - Zhenzhong Wang
- Jiangsu Kanion Pharmaceutical Co., Ltd., Lianyungang, China.,State Key Laboratory of New-tech for Chinese Medicine Pharmaceutical Process, Lianyungang, China
| |
Collapse
|
6
|
Kumar NN, Pizzo ME, Nehra G, Wilken-Resman B, Boroumand S, Thorne RG. Passive Immunotherapies for Central Nervous System Disorders: Current Delivery Challenges and New Approaches. Bioconjug Chem 2018; 29:3937-3966. [PMID: 30265523 PMCID: PMC7234797 DOI: 10.1021/acs.bioconjchem.8b00548] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Passive immunotherapy, i.e., the administration of exogenous antibodies that recognize a specific target antigen, has gained significant momentum as a potential treatment strategy for several central nervous system (CNS) disorders, including Alzheimer's disease, Parkinson's disease, Huntington's disease, and brain cancer, among others. Advances in antibody engineering to create therapeutic antibody fragments or antibody conjugates have introduced new strategies that may also be applied to treat CNS disorders. However, drug delivery to the CNS for antibodies and other macromolecules has thus far proven challenging, due in large part to the blood-brain barrier and blood-cerebrospinal fluid barriers that greatly restrict transport of peripherally administered molecules from the systemic circulation into the CNS. Here, we summarize the various passive immunotherapy approaches under study for the treatment of CNS disorders, with a primary focus on disease-specific and target site-specific challenges to drug delivery and new, cutting edge methods.
Collapse
Affiliation(s)
- Niyanta N. Kumar
- Pharmaceutical Sciences Division, University of
Wisconsin-Madison School of Pharmacy
| | - Michelle E. Pizzo
- Pharmaceutical Sciences Division, University of
Wisconsin-Madison School of Pharmacy
- Clinical Neuroengineering Training Program, University of
Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Geetika Nehra
- Pharmaceutical Sciences Division, University of
Wisconsin-Madison School of Pharmacy
| | - Brynna Wilken-Resman
- Pharmaceutical Sciences Division, University of
Wisconsin-Madison School of Pharmacy
| | - Sam Boroumand
- Pharmaceutical Sciences Division, University of
Wisconsin-Madison School of Pharmacy
| | - Robert G. Thorne
- Pharmaceutical Sciences Division, University of
Wisconsin-Madison School of Pharmacy
- Clinical Neuroengineering Training Program, University of
Wisconsin-Madison, Madison, Wisconsin 53705, United States
- Neuroscience Training Program & Center for
Neuroscience, University of Wisconsin-Madison, Madison, Wisconsin 53705, United
States
- Cellular and Molecular Pathology Graduate Training Program,
University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| |
Collapse
|
7
|
McIntee FL, Giannoni P, Blais S, Sommer G, Neubert TA, Rostagno A, Ghiso J. In vivo Differential Brain Clearance and Catabolism of Monomeric and Oligomeric Alzheimer's Aβ protein. Front Aging Neurosci 2016; 8:223. [PMID: 27729857 PMCID: PMC5037193 DOI: 10.3389/fnagi.2016.00223] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 09/07/2016] [Indexed: 01/06/2023] Open
Abstract
Amyloid β (Aβ) is the major constituent of the brain deposits found in parenchymal plaques and cerebral blood vessels of patients with Alzheimer's disease (AD). Several lines of investigation support the notion that synaptic pathology, one of the strongest correlates to cognitive impairment, is related to the progressive accumulation of neurotoxic Aβ oligomers. Since the process of oligomerization/fibrillization is concentration-dependent, it is highly reliant on the homeostatic mechanisms that regulate the steady state levels of Aβ influencing the delicate balance between rate of synthesis, dynamics of aggregation, and clearance kinetics. Emerging new data suggest that reduced Aβ clearance, particularly in the aging brain, plays a critical role in the process of amyloid formation and AD pathogenesis. Using well-defined monomeric and low molecular mass oligomeric Aβ1-40 species stereotaxically injected into the brain of C57BL/6 wild-type mice in combination with biochemical and mass spectrometric analyses in CSF, our data clearly demonstrate that Aβ physiologic removal is extremely fast and involves local proteolytic degradation leading to the generation of heterogeneous C-terminally cleaved proteolytic products, while providing clear indication of the detrimental role of oligomerization for brain Aβ efflux. Immunofluorescence confocal microscopy studies provide insight into the cellular pathways involved in the brain removal and cellular uptake of Aβ. The findings indicate that clearance from brain interstitial fluid follows local and systemic paths and that in addition to the blood-brain barrier, local enzymatic degradation and the bulk flow transport through the choroid plexus into the CSF play significant roles. Our studies highlight the diverse factors influencing brain clearance and the participation of various routes of elimination opening up new research opportunities for the understanding of altered mechanisms triggering AD pathology and for the potential design of combined therapeutic strategies.
Collapse
Affiliation(s)
- Farron L McIntee
- Department of Pathology, New York University School of Medicine New York, NY, USA
| | - Patrizia Giannoni
- Department of Pathology, New York University School of Medicine New York, NY, USA
| | - Steven Blais
- Department of Biochemistry and Molecular Pharmacology, New York University School of MedicineNew York, NY, USA; Kimmel Center for Biology and Medicine at the Skirball Institute, New York University School of MedicineNew York, NY, USA
| | - George Sommer
- Radiation Safety Office, New York University School of Medicine New York, NY, USA
| | - Thomas A Neubert
- Department of Biochemistry and Molecular Pharmacology, New York University School of MedicineNew York, NY, USA; Kimmel Center for Biology and Medicine at the Skirball Institute, New York University School of MedicineNew York, NY, USA
| | - Agueda Rostagno
- Department of Pathology, New York University School of Medicine New York, NY, USA
| | - Jorge Ghiso
- Department of Pathology, New York University School of MedicineNew York, NY, USA; Department of Psychiatry, New York University School of MedicineNew York, NY, USA
| |
Collapse
|
8
|
Signal loss due to oligomerization in ELISA analysis of amyloid-beta can be recovered by a novel sample pre-treatment method. MethodsX 2015; 2:112-23. [PMID: 26150979 PMCID: PMC4487349 DOI: 10.1016/j.mex.2015.02.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 02/26/2015] [Indexed: 01/09/2023] Open
Abstract
According to the predominant theories, soluble amyloid-beta (Aβ) aggregates are the principal neurotoxic agents in Alzheimer’s disease pathology, making them a popular target for the development of therapeutics and diagnostic markers. One of the most commonly used methods for determining the concentration of Aβ is ELISA. However, ELISA was developed for monomeric proteins and may be ill-suited for detecting aggregates. Therefore, we investigated the effect of aggregation on the ELISA measurement and developed a novel chemical pre-treatment method, designed to disaggregate Aβ peptides, to improve the ELISA measurement of the total Aβ concentration. Synthetic Aβ40 monomers, Aβ42 oligomers and biological samples from mice and humans were subjected to a chemical pre-treatment protocol with: trifluoroacetic acid (TFA), formic acid (FA) or hexafluoroisopropanol (HFIP) prior to ELISA analysis. In our study we have shown that: Aβ oligomerization leads to epitope masking and steric hindrance and results in an underestimation of the total Aβ content with ELISA. Chemically pre-treating samples to disaggregate oligomers can (partially) recover the signal loss. This novel sample pre-treatment method could provide a more accurate ELISA measurement of the total Aβ concentration in samples with a high oligomer content.
Collapse
Key Words
- AD, Alzheimers disease
- Alzheimer’s disease
- Amyloid-beta
- Aβ, amyloid-beta
- DMSO, dimethyl sulfoxide
- ELISA
- FA, formic acid
- HFIP, hexafluoroisopropanol
- Oligomers
- PBS, phosphate-buffered saline
- PMSF, phenylmethylsulfonyl fluoride
- SDS, sodium dodecyl sulphate
- SP, soluble proteins
- Sample pre-treatment
- Sample pre-treatment for amyloid-beta ELISA analysis
- Steric hindrance
- TFA, trifluoroacetic acid
- WT, wild-type
Collapse
|
9
|
Beach TG, Adler CH, Sue LI, Serrano G, Shill HA, Walker DG, Lue L, Roher AE, Dugger BN, Maarouf C, Birdsill AC, Intorcia A, Saxon-Labelle M, Pullen J, Scroggins A, Filon J, Scott S, Hoffman B, Garcia A, Caviness JN, Hentz JG, Driver-Dunckley E, Jacobson SA, Davis KJ, Belden CM, Long KE, Malek-Ahmadi M, Powell JJ, Gale LD, Nicholson LR, Caselli RJ, Woodruff BK, Rapscak SZ, Ahern GL, Shi J, Burke AD, Reiman EM, Sabbagh MN. Arizona Study of Aging and Neurodegenerative Disorders and Brain and Body Donation Program. Neuropathology 2015; 35:354-89. [PMID: 25619230 DOI: 10.1111/neup.12189] [Citation(s) in RCA: 303] [Impact Index Per Article: 33.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 11/11/2014] [Indexed: 12/13/2022]
Abstract
The Brain and Body Donation Program (BBDP) at Banner Sun Health Research Institute (http://www.brainandbodydonationprogram.org) started in 1987 with brain-only donations and currently has banked more than 1600 brains. More than 430 whole-body donations have been received since this service was commenced in 2005. The collective academic output of the BBDP is now described as the Arizona Study of Aging and Neurodegenerative Disorders (AZSAND). Most BBDP subjects are enrolled as cognitively normal volunteers residing in the retirement communities of metropolitan Phoenix, Arizona. Specific recruitment efforts are also directed at subjects with Alzheimer's disease, Parkinson's disease and cancer. The median age at death is 82. Subjects receive standardized general medical, neurological, neuropsychological and movement disorders assessments during life and more than 90% receive full pathological examinations by medically licensed pathologists after death. The Program has been funded through a combination of internal, federal and state of Arizona grants as well as user fees and pharmaceutical industry collaborations. Subsets of the Program are utilized by the US National Institute on Aging Arizona Alzheimer's Disease Core Center and the US National Institute of Neurological Disorders and Stroke National Brain and Tissue Resource for Parkinson's Disease and Related Disorders. Substantial funding has also been received from the Michael J. Fox Foundation for Parkinson's Research. The Program has made rapid autopsy a priority, with a 3.0-hour median post-mortem interval for the entire collection. The median RNA Integrity Number (RIN) for frozen brain and body tissue is 8.9 and 7.4, respectively. More than 2500 tissue requests have been served and currently about 200 are served annually. These requests have been made by more than 400 investigators located in 32 US states and 15 countries. Tissue from the BBDP has contributed to more than 350 publications and more than 200 grant-funded projects.
Collapse
Affiliation(s)
- Thomas G Beach
- Banner Sun Health Research Institute, Sun City, Arizona, USA
| | | | - Lucia I Sue
- Banner Sun Health Research Institute, Sun City, Arizona, USA
| | - Geidy Serrano
- Banner Sun Health Research Institute, Sun City, Arizona, USA
| | - Holly A Shill
- Banner Sun Health Research Institute, Sun City, Arizona, USA
| | | | - LihFen Lue
- Banner Sun Health Research Institute, Sun City, Arizona, USA
| | - Alex E Roher
- Banner Sun Health Research Institute, Sun City, Arizona, USA
| | | | - Chera Maarouf
- Banner Sun Health Research Institute, Sun City, Arizona, USA
| | - Alex C Birdsill
- Banner Sun Health Research Institute, Sun City, Arizona, USA
| | | | | | - Joel Pullen
- Banner Sun Health Research Institute, Sun City, Arizona, USA
| | | | - Jessica Filon
- Banner Sun Health Research Institute, Sun City, Arizona, USA
| | - Sarah Scott
- Banner Sun Health Research Institute, Sun City, Arizona, USA
| | | | - Angelica Garcia
- Banner Sun Health Research Institute, Sun City, Arizona, USA
| | | | | | | | | | - Kathryn J Davis
- Banner Sun Health Research Institute, Sun City, Arizona, USA
| | | | - Kathy E Long
- Banner Sun Health Research Institute, Sun City, Arizona, USA
| | | | | | - Lisa D Gale
- Banner Sun Health Research Institute, Sun City, Arizona, USA
| | | | | | | | | | | | - Jiong Shi
- Barrow Neurological Institute, Phoenix, Arizona, USA
| | - Anna D Burke
- Banner Alzheimer Institute, Phoenix, Arizona, USA
| | | | | |
Collapse
|
10
|
Iram A, Naeem A. Protein Folding, Misfolding, Aggregation and Their Implications in Human Diseases: Discovering Therapeutic Ways to Amyloid-Associated Diseases. Cell Biochem Biophys 2014; 70:51-61. [DOI: 10.1007/s12013-014-9904-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
11
|
Watson D, Castaño E, Kokjohn TA, Kuo YM, Lyubchenko Y, Pinsky D, Connolly ES, Esh C, Luehrs DC, Stine WB, Rowse LM, Emmerling MR, Roher AE. Physicochemical characteristics of soluble oligomeric Aβand their pathologic role in Alzheimer's disease. Neurol Res 2013; 27:869-81. [PMID: 16354549 DOI: 10.1179/016164105x49436] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Extracellular fibrillar amyloid deposits are prominent and universal Alzheimer's disease (AD) features, but senile plaque abundance does not always correlate directly with the degree of dementia exhibited by AD patients. The mechanism(s) and dynamics of Abeta fibril genesis and deposition remain obscure. Enhanced Abeta synthesis rates coupled with decreased degradative enzyme production and accumulating physical modifications that dampen proteolysis may all enhance amyloid deposit formation. Amyloid accumulation may indirectly exert the greatest pathologic effect on the brain vasculature by destroying smooth muscle cells and creating a cascade of negative impacts on cerebral blood flow. The most visible manifestation of amyloid dis-equilibrium could actually be a defense mechanism employed to avoid serious vascular wall degradation while the major toxic effects to the gray and white matter neurons are mediated by soluble oligomeric Abeta peptides with high beta-sheet content. The recognition that dynamic soluble oligomeric Abeta pools exist in AD and are correlated to disease severity led to neurotoxicity and physical conformation studies. It is now recognized that the most basic soluble Abeta peptides are stable dimers with hydrophobic regions sequestered from the aqueous environment and are capable of higher order aggregations. Time course experiments employing a modified ELISA method able to detect Abeta oligomers revealed dynamic intermolecular interactions and additional experiments physically confirmed the presence of stable amyloid multimers. Amyloid peptides that are rich in beta-sheet structure are capable of creating toxic membrane ion channels and a capacity to self-assemble as annular structures was confirmed in vitro using atomic force microscopy. Biochemical studies have established that soluble Abeta peptides perturb metabolic processes, provoke release of deleterious reactive compounds, reduce blood flow, induce mitochondrial apoptotic toxicity and inhibit angiogenesis. While there is no question that gross amyloid deposition does contribute to AD pathology, the destructive potential now associated with soluble Abeta suggests that treatment strategies that target these molecules may be efficacious in preventing some of the devastating effects of AD.
Collapse
Affiliation(s)
- Desiree Watson
- Pfizer, Global Research and Development, Ann Arbor, MI 48106 USA
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Yanagi K, Sakurai K, Yoshimura Y, Konuma T, Lee YH, Sugase K, Ikegami T, Naiki H, Goto Y. The Monomer–Seed Interaction Mechanism in the Formation of the β2-Microglobulin Amyloid Fibril Clarified by Solution NMR Techniques. J Mol Biol 2012; 422:390-402. [DOI: 10.1016/j.jmb.2012.05.034] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Revised: 04/30/2012] [Accepted: 05/29/2012] [Indexed: 11/15/2022]
|
13
|
Youmans KL, Wolozin B. TDP-43: a new player on the AD field? Exp Neurol 2012; 237:90-5. [PMID: 22691390 DOI: 10.1016/j.expneurol.2012.05.018] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Revised: 05/17/2012] [Accepted: 05/27/2012] [Indexed: 12/20/2022]
|
14
|
Steckmann T, Awan Z, Gerstman BS, Chapagain PP. Kinetics of peptide secondary structure conversion during amyloid β-protein fibrillogenesis. J Theor Biol 2012; 301:95-102. [DOI: 10.1016/j.jtbi.2012.02.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
15
|
Pryor NE, Moss MA, Hestekin CN. Unraveling the early events of amyloid-β protein (Aβ) aggregation: techniques for the determination of Aβ aggregate size. Int J Mol Sci 2012; 13:3038-3072. [PMID: 22489141 PMCID: PMC3317702 DOI: 10.3390/ijms13033038] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Revised: 02/09/2012] [Accepted: 02/23/2012] [Indexed: 11/16/2022] Open
Abstract
The aggregation of proteins into insoluble amyloid fibrils coincides with the onset of numerous diseases. An array of techniques is available to study the different stages of the amyloid aggregation process. Recently, emphasis has been placed upon the analysis of oligomeric amyloid species, which have been hypothesized to play a key role in disease progression. This paper reviews techniques utilized to study aggregation of the amyloid-β protein (Aβ) associated with Alzheimer's disease. In particular, the review focuses on techniques that provide information about the size or quantity of oligomeric Aβ species formed during the early stages of aggregation, including native-PAGE, SDS-PAGE, Western blotting, capillary electrophoresis, mass spectrometry, fluorescence correlation spectroscopy, light scattering, size exclusion chromatography, centrifugation, enzyme-linked immunosorbent assay, and dot blotting.
Collapse
MESH Headings
- Alzheimer Disease/etiology
- Alzheimer Disease/metabolism
- Amyloid beta-Peptides/chemistry
- Amyloid beta-Peptides/metabolism
- Blotting, Western
- Chromatography, Gel
- Disease Progression
- Electrophoresis, Capillary
- Electrophoresis, Polyacrylamide Gel
- Humans
- Particle Size
- Protein Aggregates
- Protein Aggregation, Pathological
- Protein Multimerization
- Protein Structure, Quaternary
- Scattering, Radiation
- Spectrometry, Fluorescence
- Spectrometry, Mass, Electrospray Ionization
- Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
Collapse
Affiliation(s)
- N. Elizabeth Pryor
- Ralph E. Martin Department of Chemical Engineering, 3202 Bell Engineering Center, University of Arkansas, Fayetteville, AR 72701, USA; E-Mail:
| | - Melissa A. Moss
- Department of Chemical Engineering, 2C02 Swearingen Engineering Center, University of South Carolina, Columbia, SC 29208, USA; E-Mail:
| | - Christa N. Hestekin
- Ralph E. Martin Department of Chemical Engineering, 3202 Bell Engineering Center, University of Arkansas, Fayetteville, AR 72701, USA; E-Mail:
| |
Collapse
|
16
|
Staton SJR, Jones PV, Ku G, Gilman SD, Kheterpal I, Hayes MA. Manipulation and capture of Aβ amyloid fibrils and monomers by DC insulator gradient dielectrophoresis (DC-iGDEP). Analyst 2012; 137:3227-9. [DOI: 10.1039/c2an35138b] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
17
|
Muzaffar M, Ahmad A. The mechanism of enhanced insulin amyloid fibril formation by NaCl is better explained by a conformational change model. PLoS One 2011; 6:e27906. [PMID: 22132167 PMCID: PMC3221682 DOI: 10.1371/journal.pone.0027906] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Accepted: 10/27/2011] [Indexed: 01/05/2023] Open
Abstract
The high propensity of insulin to fibrillate causes severe biomedical and biotechnological complications. Insulin fibrillation studies attain significant importance considering the prevalence of diabetes and the requirement of functional insulin in each dose. Although studied since the early years of the 20(th) century, elucidation of the mechanism of insulin fibrillation has not been understood completely. We have previously, through several studies, shown that insulin hexamer dissociates into monomer that undergoes partial unfolding before converting into mature fibrils. In this study we have established that NaCl enhances insulin fibrillation mainly due to subtle structural changes and is not a mere salt effect. We have carried out studies both in the presence and absence of urea and Gdn.HCl and compared the relationship between conformation of insulin induced by urea and Gdn.HCl with respect to NaCl at both pH 7.4 (hexamer) and pH 2 (monomer). Fibril formation was followed with a Thioflavin T assay and structural changes were monitored by circular dichroism and size-exclusion chromatography. The results show salt-insulin interactions are difficult to classify as commonly accepted Debye-Hückel or Hofmeister series interactions but instead a strong correlation between the association states and conformational states of insulin and their propensity to fibrillate is evident.
Collapse
Affiliation(s)
- Mahvish Muzaffar
- Department of Biological Chemistry and Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, United States of America
| | | |
Collapse
|
18
|
Sehlin D, Hedlund M, Lord A, Englund H, Gellerfors P, Paulie S, Lannfelt L, Pettersson FE. Heavy-chain complementarity-determining regions determine conformation selectivity of anti-aβ antibodies. NEURODEGENER DIS 2010; 8:117-23. [PMID: 20714111 DOI: 10.1159/000316530] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2010] [Accepted: 06/03/2010] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND/AIMS Amyloid-β (Aβ) protofibrils are neurotoxic soluble intermediates in the Aβ aggregation process eventually forming senile plaques in Alzheimer's disease. This Aβ species is a potential biomarker for Alzheimer's disease and also a promising target for immunotherapy. In this study, we investigated the characteristics of conformation-dependent Aβ antibodies specific for Aβ protofibrils. METHODS Mice were immunized with Aβ protofibrils to generate hybridomas producing Aβ-specific monoclonal antibodies. Binding of antibodies to different Aβ conformations was investigated with inhibition ELISA. The antibodies' complementarity-determining region (CDR) sequences were determined and compared. RESULTS A majority of the antibodies were of the IgM class, all selectively binding to aggregated Aβ. Two IgG antibodies were generated: one with selective affinity for Aβ protofibrils and the other bound Aβ in all conformations. A high degree of similarity between the heavy-chain CDRs of the conformation-dependent antibodies was found, and all high-affinity Aβ antibodies displayed a high degree of sequence similarity in the light-chain CDRs. CONCLUSION Sequence similarity in the heavy-chain CDRs is associated with conformation selectivity of the antibodies, while sequence similarity in the light-chain CDRs correlates with the affinity for Aβ.
Collapse
Affiliation(s)
- Dag Sehlin
- Department of Public Health/Molecular Geriatrics, Rudbeck Laboratory Uppsala University, Uppsala, Sweden
| | | | | | | | | | | | | | | |
Collapse
|
19
|
Valle‐Delgado JJ, Alfonso‐Prieto M, Groot NS, Ventura S, Samitier J, Rovira C, Fernàndez‐Busquets X. Modulation of Aβ
42
fìbrillogenesis by glycosaminoglycan structure. FASEB J 2010; 24:4250-61. [DOI: 10.1096/fj.09-153551] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Juan José Valle‐Delgado
- Nanobioengineering GroupInstitute for Bioengineering of Catalonia Barcelona Spain
- Biomolecular Interactions TeamNanoscience and Nanotechnology Institute Barcelona Spain
| | - Mercedes Alfonso‐Prieto
- Institut de Química Teòrica i Computacional Barcelona Spain
- Computer Simulation and Modeling Laboratory (CoSMo LAB) Barcelona Spain
| | - Natalia S. Groot
- Institut de Biotecnologia i de BiomedicinaDepartament de Bioquímica i Biologia MolecularUniversitat Autònoma de Barcelona Barcelona Spain
| | - Salvador Ventura
- Institut de Biotecnologia i de BiomedicinaDepartament de Bioquímica i Biologia MolecularUniversitat Autònoma de Barcelona Barcelona Spain
| | - Josep Samitier
- Nanobioengineering GroupInstitute for Bioengineering of Catalonia Barcelona Spain
- Department of ElectronicsUniversity of Barcelona Barcelona Spain
| | - Carme Rovira
- Institut de Química Teòrica i Computacional Barcelona Spain
- Computer Simulation and Modeling Laboratory (CoSMo LAB) Barcelona Spain
- Institució Catalana de Recerca i Estudis Avançats Barcelona Spain
| | - Xavier Fernàndez‐Busquets
- Nanobioengineering GroupInstitute for Bioengineering of Catalonia Barcelona Spain
- Biomolecular Interactions TeamNanoscience and Nanotechnology Institute Barcelona Spain
| |
Collapse
|
20
|
Jan A, Hartley DM, Lashuel HA. Preparation and characterization of toxic Abeta aggregates for structural and functional studies in Alzheimer's disease research. Nat Protoc 2010; 5:1186-209. [PMID: 20539293 DOI: 10.1038/nprot.2010.72] [Citation(s) in RCA: 198] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The amyloid cascade hypothesis, supported by strong evidence from genetics, pathology and studies using animal models, implicates amyloid-beta (Abeta) oligomerization and fibrillogenesis as central causative events in the pathogenesis of Alzheimer's disease (AD). Today, significant efforts in academia, biotechnology and the pharmaceutical industry are devoted to identifying the mechanisms by which the process of Abeta aggregation contributes to neurodegeneration in AD and to the identity of the toxic Abeta species. In this paper, we describe methods and detailed protocols for reproducibly preparing Abeta aggregates of defined size distribution and morphology, including monomers, protofibrils and fibrils, using size exclusion chromatography. In addition, we describe detailed biophysical procedures for elucidating the structural features, aggregation kinetics and toxic properties of the different Abeta aggregation states, with special emphasis on protofibrillar intermediates. The information provided by this approach allows for consistent correlation between the properties of the aggregates and their toxicity toward primary neurons and/or cell lines. A better understanding of the molecular and structural basis of Abeta aggregation and toxicity is crucial for the development of effective strategies aimed at prevention and/or treatment of AD. Furthermore, the identification of specific aggregation states, which correlate with neurodegeneration in AD, could lead to the development of diagnostic tools to detect and monitor disease progression. The procedures described can be performed in as little as 1 day, or may take longer, depending on the exact toxicity assays used.
Collapse
Affiliation(s)
- Asad Jan
- Laboratory of Molecular Neurobiology and Neuroproteomics, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | | | | |
Collapse
|
21
|
Abstract
The aggregation of the amyloid-beta (Abeta) peptide plays a pivotal role in the pathogenesis of Alzheimer's disease, as soluble oligomers are intimately linked to neuronal toxicity and inhibition of hippocampal long-term potentiation (LTP). In the C-terminal region of Abeta there are three consecutive GxxxG dimerization motifs, which we could previously demonstrate to play a critical role in the generation of Abeta. Here, we show that glycine 33 (G33) of the central GxxxG interaction motif within the hydrophobic Abeta sequence is important for the aggregation dynamics of the peptide. Abeta peptides with alanine or isoleucine substitutions of G33 displayed an increased propensity to form higher oligomers, which we could attribute to conformational changes. Importantly, the oligomers of G33 variants were much less toxic than Abeta(42) wild type (WT), in vitro and in vivo. Also, whereas Abeta(42) WT is known to inhibit LTP, Abeta(42) G33 variants had lost the potential to inhibit LTP. Our findings reveal that conformational changes induced by G33 substitutions unlink toxicity and oligomerization of Abeta on the molecular level and suggest that G33 is the key amino acid in the toxic activity of Abeta. Thus, a specific toxic conformation of Abeta exists, which represents a promising target for therapeutic interventions.
Collapse
|
22
|
Ma G, Gao J, Fu Q, Jiang L, Wang R, Zhang Y, Liu K. Diazoxide Reverses the Enhanced Expression of KATP Subunits in Cholinergic Neurons Caused by Exposure to Aβ1-42. Neurochem Res 2009; 34:2133-40. [DOI: 10.1007/s11064-009-0007-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/19/2009] [Indexed: 10/20/2022]
|
23
|
Amyloid-beta peptide (Abeta) neurotoxicity is modulated by the rate of peptide aggregation: Abeta dimers and trimers correlate with neurotoxicity. J Neurosci 2009; 28:11950-8. [PMID: 19005060 DOI: 10.1523/jneurosci.3916-08.2008] [Citation(s) in RCA: 162] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Alzheimer's disease is an age-related neurodegenerative disorder with its toxicity linked to the generation of amyloid-beta peptide (Abeta). Within the Abeta sequence, there is a systemic repeat of a GxxxG motif, which theoretical studies have suggested may be involved in both peptide aggregation and membrane perturbation, processes that have been implicated in Abeta toxicity. We synthesized modified Abeta peptides, substituting glycine for leucine residues within the GxxxG repeat motif (GSL peptides). These GSL peptides undergo beta-sheet and fibril formation at an increased rate compared with wild-type Abeta. The accelerated rate of amyloid fibril formation resulted in a decrease in the presence of small soluble oligomers such as dimeric and trimeric forms of Abeta in solution, as detected by mass spectrometry. This reduction in the presence of small soluble oligomers resulted in reduced binding to lipid membranes and attenuated toxicity for the GSL peptides. The potential role that dimer and trimer species binding to lipid plays in Abeta toxicity was further highlighted when it was observed that annexin V, a protein that inhibits Abeta toxicity, specifically inhibited Abeta dimers from binding to lipid membranes.
Collapse
|
24
|
Bravo R, Arimon M, Valle-Delgado JJ, García R, Durany N, Castel S, Cruz M, Ventura S, Fernàndez-Busquets X. Sulfated Polysaccharides Promote the Assembly of Amyloid β1–42 Peptide into Stable Fibrils of Reduced Cytotoxicity. J Biol Chem 2008; 283:32471-83. [DOI: 10.1074/jbc.m709870200] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
|
25
|
van Helmond Z, Heesom K, Love S. Characterisation of two antibodies to oligomeric Abeta and their use in ELISAs on human brain tissue homogenates. J Neurosci Methods 2008; 176:206-12. [PMID: 18824027 DOI: 10.1016/j.jneumeth.2008.09.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2008] [Revised: 08/28/2008] [Accepted: 09/01/2008] [Indexed: 12/16/2022]
Abstract
Oligomeric forms of Abeta are believed to be the major toxic species of this peptide in Alzheimer's disease (AD). Although the characterisation of oligomer-specific antibodies has been reported, these have not been successfully incorporated into an enzyme-linked immunosorbent assay (ELISA), and measurement of the levels of oligomeric Abeta in brain tissue has remained problematic. We have examined the specificity of two monoclonal antibodies, 7 A1a and 1G5, for synthetic oligomers of Abeta(1-42) and for oligomeric Abeta(1-42) in human brain homogenates, and the utility of these two antibodies for measuring oligomeric Abeta(1-42) by sandwich ELISA. Both antibodies were found to recognise a range of synthetic oligomers of Abeta(1-42) but to cross-react in Western blots with a 34 kDa protein, shown by two-dimensional gel electrophoresis and mass spectrometry to be tropomyosin. However, by using 7A1a and 1 G5 in combination with an Abeta(1-42) capture antibody, we were able specifically to detect and to measure the levels of oligomeric Abeta(1-42) in brain homogenates by ELISA. The development of a simple ELISA for measurement of oligomeric Abeta should facilitate further studies of the role of oligomeric species of Abeta in AD.
Collapse
Affiliation(s)
- Zoë van Helmond
- Dementia Research Group, Institute of Clinical Neurosciences, Clinical Science at North Bristol, University of Bristol, Bristol BS16 1LE, UK.
| | | | | |
Collapse
|
26
|
Rambaran RN, Serpell LC. Amyloid fibrils: abnormal protein assembly. Prion 2008; 2:112-7. [PMID: 19158505 PMCID: PMC2634529 DOI: 10.4161/pri.2.3.7488] [Citation(s) in RCA: 330] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2008] [Accepted: 11/20/2008] [Indexed: 01/29/2023] Open
Abstract
Amyloid refers to the abnormal fibrous, extracellular, proteinaceous deposits found in organs and tissues. Amyloid is insoluble and is structurally dominated by beta-sheet structure. Unlike other fibrous proteins it does not commonly have a structural, supportive or motility role but is associated with the pathology seen in a range of diseases known as the amyloidoses. These diseases include Alzheimer's, the spongiform encephalopathies and type II diabetes, all of which are progressive disorders with associated high morbidity and mortality. Not surprisingly, research into the physicochemical properties of amyloid and its formation is currently intensely pursued. In this chapter we will highlight the key scientific findings and discuss how the stability of amyloid fibrils impacts on bionanotechnology.
Collapse
Affiliation(s)
- Roma N Rambaran
- Department of Chemistry and Biochemistry, School of Life Sciences, University of Sussex, Falmer, UK
| | | |
Collapse
|
27
|
On the key role played by altered protein conformation in Parkinson’s disease. J Neural Transm (Vienna) 2008; 115:1285-99. [DOI: 10.1007/s00702-008-0072-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2008] [Accepted: 05/14/2008] [Indexed: 12/29/2022]
|
28
|
Effects of Aβ1–42 on the Subunits of KATP Expression in Cultured Primary Rat Basal Forebrain Neurons. Neurochem Res 2008; 33:1419-24. [DOI: 10.1007/s11064-008-9603-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2007] [Accepted: 01/23/2008] [Indexed: 10/22/2022]
|
29
|
Herczenik E, Gebbink MFBG. Molecular and cellular aspects of protein misfolding and disease. FASEB J 2008; 22:2115-33. [PMID: 18303094 DOI: 10.1096/fj.07-099671] [Citation(s) in RCA: 148] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Proteins are essential elements for life. They are building blocks of all organisms and the operators of cellular functions. Humans produce a repertoire of at least 30,000 different proteins, each with a different role. Each protein has its own unique sequence and shape (native conformation) to fulfill its specific function. The appearance of incorrectly shaped (misfolded) proteins occurs on exposure to environmental changes. Protein misfolding and the subsequent aggregation is associated with various, often highly debilitating, diseases for which no sufficient cure is available yet. In the first part of this review we summarize the structural composition of proteins and the current knowledge of underlying forces that lead proteins to lose their native structure. In the second and third parts we describe the molecular and cellular mechanisms that are associated with protein misfolding in disease. Finally, in the last part we portray recent efforts to develop treatments for protein misfolding diseases.
Collapse
Affiliation(s)
- Eszter Herczenik
- Laboratory of Thrombosis and Haemostasis, Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | | |
Collapse
|
30
|
Zhao JH, Liu HL, Lin HY, Huang CH, Fang HW, Chen SS, Ho Y, Tsai WB, Chen WY. Chemical chaperone and inhibitor discovery: potential treatments for protein conformational diseases. PERSPECTIVES IN MEDICINAL CHEMISTRY 2007; 1:39-48. [PMID: 19812735 PMCID: PMC2754919 DOI: 10.4137/pmc.s212] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Protein misfolding and aggregation cause a large number of neurodegenerative diseases in humans due to (i) gain of function as observed in Alzheimer’s disease, Huntington’s disease, Parkinson’s disease, and Prion’s disease or (ii) loss of function as observed in cystic fibrosis and α1-antitrypsin deficiency. These misfolded proteins could either lead to the formation of harmful amyloids that become toxic for the cells or to be recognized and prematurely degraded by the protein quality control system. An increasing number of studies has indicated that some low-molecular-weight compounds named as chemical chaperones can reverse the mislocalization and/or aggregation of proteins associated with human conformational diseases. These small molecules are thought to non-selectively stabilize proteins and facilitate their folding. In this review, we summarize the probable mechanisms of protein conformational diseases in humans and the use of chemical chaperones and inhibitors as potential therapeutic agents against these diseases. Furthermore, recent advanced experimental and theoretical approaches underlying the detailed mechanisms of protein conformational changes and current structure-based drug designs towards protein conformational diseases are also discussed. It is believed that a better understanding of the mechanisms of conformational changes as well as the biological functions of these proteins will lead to the development and design of potential interfering compounds against amyloid formation associated with protein conformational diseases.
Collapse
Affiliation(s)
- Jian-Hua Zhao
- Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, 1 Sec. 3 ZhongXiao E. Rd., Taipei 10608
| | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Arriagada C, Astorga C, Atwater I, Rojas E, Mears D, Caviedes R, Caviedes P. Endosomal abnormalities related to amyloid precursor protein in cholesterol treated cerebral cortex neuronal cells derived from trisomy 16 mice, an animal model of Down syndrome. Neurosci Lett 2007; 423:172-7. [PMID: 17706358 DOI: 10.1016/j.neulet.2007.06.054] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2007] [Revised: 06/11/2007] [Accepted: 06/22/2007] [Indexed: 11/22/2022]
Abstract
The CNh and CTb cell lines are derived from the cerebral cortex of normal and trisomy 16 mice, an animal model of human trisomy 21, Down syndrome (DS), and represent in vitro models to study cellular events associated with the human condition. Amyloid precursor protein (APP) plays an important role in the development of neuropathology associated with DS and cholesterol in the amyloidogenic processing of APP. There is also increasing evidence of alterations in the recycling pathway of the early endosome compartment in nervous tissue from DS. In the present study, we report endosomal abnormalities related to amyloid precursor protein in cholesterol-treated CTb cells. Colocalization studies revealed the presence of APP-derived products in early endosomal compartments in both cell lines. Using internalization and immunoprecipitation techniques, differential effects were observed between the normal and trisomic cell lines when treated with cholesterol. Internalization experiments showed that the CTb cell line accumulates internalized APP in intracellular compartments for longer periods of time when compared to the CNh cell line. Immunoprecipitation revealed a differential interaction between the trafficking-related protein Rab4 and APP in the neuronal cell lines CNh and CTb. The present study suggests a putative mechanism by which overexpressed APP accumulates in intracellular compartments related to the endosomal trafficking pathway in individuals with DS, and highlights the usefulness of the CTb cell line as a model to study altered APP metabolism related to this genetic condition.
Collapse
Affiliation(s)
- Christian Arriagada
- ICBM, Program of Anatomy and Developmental Biology, Faculty of Medicine, University of Chile, Casilla 70079, Correo 7, Santiago, Chile.
| | | | | | | | | | | | | |
Collapse
|
32
|
Lee S, Fernandez EJ, Good TA. Role of aggregation conditions in structure, stability, and toxicity of intermediates in the Abeta fibril formation pathway. Protein Sci 2007; 16:723-32. [PMID: 17327396 PMCID: PMC2203338 DOI: 10.1110/ps.062514807] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
beta-amyloid peptide (Abeta) is one of the main protein components of senile plaques associated with Alzheimer's disease (AD). Abeta readily aggregates to forms fibrils and other aggregated species that have been shown to be toxic in a number of studies. In particular, soluble oligomeric forms are closely related to neurotoxicity. However, the relationship between neurotoxicity and the size of Abeta aggregates or oligomers is still under investigation. In this article, we show that different Abeta incubation conditions in vitro can affect the rate of Abeta fibril formation, the conformation and stability of intermediates in the aggregation pathway, and toxicity of aggregated species formed. When gently agitated, Abeta aggregates faster than Abeta prepared under quiescent conditions, forming fibrils. The morphology of fibrils formed at the end of aggregation with or without agitation, as observed in electron micrographs, is somewhat different. Interestingly, intermediates or oligomers formed during Abeta aggregation differ greatly under agitated and quiescent conditions. Unfolding studies in guanidine hydrochloride indicate that fibrils formed under quiescent conditions are more stable to unfolding in detergent than aggregation associated oligomers or Abeta fibrils formed with agitation. In addition, Abeta fibrils formed under quiescent conditions were less toxic to differentiated SH-SY5Y cells than the Abeta aggregation associated oligomers or fibrils formed with agitation. These results highlight differences between Abeta aggregation intermediates formed under different conditions and provide insight into the structure and stability of toxic Abeta oligomers.
Collapse
Affiliation(s)
- Sungmun Lee
- Department of Chemical Engineering, Texas A&M University, College Station, Texas 77843-3122, USA
| | | | | |
Collapse
|
33
|
Frid P, Anisimov SV, Popovic N. Congo red and protein aggregation in neurodegenerative diseases. ACTA ACUST UNITED AC 2007; 53:135-60. [PMID: 16959325 DOI: 10.1016/j.brainresrev.2006.08.001] [Citation(s) in RCA: 253] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2006] [Accepted: 08/02/2006] [Indexed: 11/19/2022]
Abstract
Congo red is a commonly used histological dye for amyloid detection. The specificity of this staining results from Congo red's affinity for binding to fibril proteins enriched in beta-sheet conformation. Unexpectedly, recent investigations indicate that the dye also possesses the capacity to interfere with processes of protein misfolding and aggregation, stabilizing native protein monomers or partially folded intermediates, while reducing concentration of more toxic protein oligomers. Inhibitory effects of Congo red upon amyloid toxicity may also range from blockade of channel formation and interference with glycosaminoglycans binding or immune functions, to the modulation of gene expression. Particularly, Congo red exhibits ameliorative effect in models of neurodegenerative disorders, such as Alzheimer's, Parkinson's, Huntington's and prion diseases. Another interesting application of Congo red analogues is the development of imaging probes. Based on their small molecular size and penetrability through blood-brain barrier, Congo red congeners can be used for both antemortem and in vivo visualization and quantification of brain amyloids. Therefore, understanding mechanisms involved in dye-amyloidal fibril binding and inhibition of aggregation will provide instructive guides for the design of future compounds, potentially useful for monitoring and treating neurodegenerative diseases.
Collapse
Affiliation(s)
- Petrea Frid
- Neuronal Survival Unit, Wallenberg Neuroscience Center, Lund University, Sweden
| | | | | |
Collapse
|
34
|
|
35
|
Morbo di Alzheimer. Neurologia 2007. [DOI: 10.1016/s1634-7072(07)70544-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
|
36
|
Yuan C, Berscheit HL, Huang AJW. Identification of an amyloidogenic region on keratoepithelin via synthetic peptides. FEBS Lett 2006; 581:241-7. [PMID: 17207483 DOI: 10.1016/j.febslet.2006.12.019] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2006] [Revised: 12/05/2006] [Accepted: 12/07/2006] [Indexed: 11/16/2022]
Abstract
Mutations of keratoepithelin (KE) gene in human chromosome 5q31 have been linked with corneal epithelial or stromal dystrophies characterized by the abnormal deposits of amyloid fibrils and/or non-amyloid aggregations in corneal tissue. We report herein that synthetic peptide containing amino acid (a.a.) residues of 515-532 of native KE protein can readily form beta-sheet-containing amyloid fibrils in vitro. Amyloid fibrils formed in various conditions from short synthetic peptides (containing a.a. 515-532 and 515-525, respectively) were characterized by thioflavin T (ThT) fluorescence assay, Congo red staining, electron microscopy (EM) and circular dichroism (CD). Triple-N-methylation of the synthetic peptides prevented the beta-sheet polymerization and related amyloid fibril formation. Comparison study with ThT fluorescence further demonstrated that synthetic peptides containing corneal dystrophy-related mutations within this region formed amyloid fibrils to various extents. Our results suggest that each individual dystrophy-related mutation by itself does not necessarily potentiate amyloid fibril formation of KE. Roles of these intrinsically amyloidogenic foci in abnormal KE aggregations and amyloid deposits of stromal corneal dystrophies await further investigation.
Collapse
Affiliation(s)
- Ching Yuan
- Department of Ophthalmology, University of Minnesota, Minneapolis, MN 55455, USA.
| | | | | |
Collapse
|
37
|
Agnati LF, Genedani S, Leo G, Forni A, Woods AS, Filaferro M, Franco R, Fuxe K. Aβ peptides as one of the crucial volume transmission signals in the trophic units and their interactions with homocysteine. Physiological implications and relevance for Alzheimer’s disease. J Neural Transm (Vienna) 2006; 114:21-31. [PMID: 16969627 DOI: 10.1007/s00702-006-0564-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2005] [Accepted: 07/14/2006] [Indexed: 01/11/2023]
Abstract
Amyloid peptides (Abeta) can operate as volume transmission (VT) signals since they are continuously released from cells of the central nervous system and diffuse in the extra-cellular space of the brain. They have both regulatory and trophic functions on cellular networks. In agreement with Abeta regulatory actions on glial-neuronal networks, the present paper reports new findings demonstrating that intrastriatal injections of Abeta peptides reduce striatal tyrosine hydroxylase, increase striatal GFAP immunoreactivities and lower pain threshold in experimental rats. Furthermore, it has been demonstrated that exogenous homocysteine (Hcy) binds Abeta(1-40) favouring its beta-sheet conformation both in vitro and in vivo and hence the formation of beta-fibrils and development of neurotoxicity. Thus, the hypothesis is discussed that Abeta peptides represent crucial VT-signals in the brain and their action is altered by dysmetabolic signals such as high Hcy extra-cellular levels, known to be an important risk factor for Alzheimer's disease.
Collapse
Affiliation(s)
- L F Agnati
- Department of Biomedical Sciences, Section of Physiology, University of Modena and Reggio Emilia, Modena, Italy.
| | | | | | | | | | | | | | | |
Collapse
|
38
|
Costantini C, Della-Bianca V, Formaggio E, Chiamulera C, Montresor A, Rossi F. The expression of p75 neurotrophin receptor protects against the neurotoxicity of soluble oligomers of β-amyloid. Exp Cell Res 2005; 311:126-34. [PMID: 16223482 DOI: 10.1016/j.yexcr.2005.09.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2005] [Revised: 09/08/2005] [Accepted: 09/08/2005] [Indexed: 10/25/2022]
Abstract
In this paper, evidence is provided that p75 neurotrophin receptor (p75NTR) exerts an opposite role on the cytotoxic function of beta-amyloid (Abeta) depending on the different state of the peptide, fibrillar or oligomeric soluble form. Previous work in our laboratory has shown that the expression of p75NTR is required for cell death in vitro by Abeta peptides in fibrillar form (G. Perini, V. Della-Bianca, V. Politi, G. Della Valle, I. Dal-Pra, F. Rossi, U. Armato. Role of p75 neurotrophin receptor in the neurotoxicity by beta-amyloid peptides and synergistic effect of inflammatory cytokines. J. Exp. Med. 195 (2002) 907-918). In the present study, performed by using the same cell clones and procedures as in previous paper, we show that: (a) soluble oligomers of Abeta(1-42) exert a cytotoxic activity independent of p75NTR, (b) the expression of p75NTR exerts a protective role against the toxic activity of soluble oligomers, (c) this role is due to an active function of the juxtamembrane sequence of the cytoplasmic region of p75NTR and (d) the protective function is mediated by phosphatidylinositide 3-kinase (PI3K) activity.
Collapse
Affiliation(s)
- Claudio Costantini
- Department of Pathology, Section of General Pathology, University of Verona, Strada Le Grazie 8, 37134 Verona, Italy
| | | | | | | | | | | |
Collapse
|
39
|
Lee SM, Jeon R. Synthesis of 6-[2-(Benzoxazol-2-ylmethylamino)ethoxy]-1-Alkyl-1H-lndole-2-Carboxylic acid and inhibitory activity on β-Amyloid aggregation. Arch Pharm Res 2005; 28:1219-23. [PMID: 16350844 DOI: 10.1007/bf02978201] [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] [Indexed: 01/19/2023]
Abstract
6-[2-(benzoxazol-2-ylmethylamino)ethoxy]-1-alkyl-1H-indole-2-carboxylic acids were designed and synthesized as beta-amyloid (Abeta) fibril assembly inhibitors. Their inhibitory activity on Abeta, aggregation was evaluated by thioflavin T assay although their activities were insignificant.
Collapse
Affiliation(s)
- Sun Mi Lee
- College of Pharmacy, Sookmyung Women's University, Seoul 140-742, Korea
| | | |
Collapse
|
40
|
Galea C, Bowman P, Kriwacki RW. Disruption of an intermonomer salt bridge in the p53 tetramerization domain results in an increased propensity to form amyloid fibrils. Protein Sci 2005; 14:2993-3003. [PMID: 16260757 PMCID: PMC2253254 DOI: 10.1110/ps.051622005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
We describe in molecular detail how disruption of an intermonomer salt bridge (Arg337-Asp352) leads to partial destabilization of the p53 tetramerization domain and a dramatically increased propensity to form amyloid fibrils. At pH 4.0 and 37 degrees C, a p53 tetramerization domain mutant (p53tet-R337H), associated with adrenocortical carcinoma in children, readily formed amyloid fibrils, while the wild-type (p53tet-wt) did not. We characterized these proteins by equilibrium denaturation, 13C(alpha) secondary chemical shifts, (1H)-15N heteronuclear NOEs, and H/D exchange. Although p53tet-R337H was thermodynamically less stable, NMR data indicated that the two proteins had similar secondary structure and molecular dynamics. NMR derived pK(a) values indicated that at low pH the R337H mutation partially disrupted an intermonomer salt bridge. Backbone H/D exchange results showed that for at least a small population of p53tet-R337H molecules disruption of this salt bridge resulted in partial destabilization of the protein. It is proposed that this decrease in p53tet-R337H stability resulted in an increased propensity to form amyloid fibrils.
Collapse
Affiliation(s)
- Charles Galea
- Department of Structural Biology, St. Jude Children's Research Hospital, 332 North Lauderdale Street, Memphis, TN 38105, USA
| | | | | |
Collapse
|
41
|
Stenh C, Englund H, Lord A, Johansson AS, Almeida CG, Gellerfors P, Greengard P, Gouras GK, Lannfelt L, Nilsson LNG. Amyloid-beta oligomers are inefficiently measured by enzyme-linked immunosorbent assay. Ann Neurol 2005; 58:147-50. [PMID: 15984012 DOI: 10.1002/ana.20524] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Amyloid-beta (Abeta) peptide levels are widely measured by enzyme-linked immunosorbent assay (ELISA) in Alzheimer's disease research. Here, we show that oligomerization of Abeta results in underestimated Abeta ELISA levels. The implications are that comprehensive analysis of soluble Abeta requires either sample pretreatment at denaturing conditions or novel conformation-dependent immunoassays. Our findings might be of relevance for many neurodegenerative disorders in which soluble protein aggregates are the main neurotoxic species.
Collapse
Affiliation(s)
- Charlotte Stenh
- Department of Public Health/Geriatrics, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden
| | | | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Mathura VS, Paris D, Ait-Ghezala G, Quadros A, Patel NS, Kolippakkam DN, Volmar CH, Mullan MJ. Model of Alzheimer's disease amyloid-beta peptide based on a RNA binding protein. Biochem Biophys Res Commun 2005; 332:585-92. [PMID: 15896718 DOI: 10.1016/j.bbrc.2005.04.164] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2005] [Accepted: 04/29/2005] [Indexed: 11/25/2022]
Abstract
Although Alzheimer's Abeta peptide has been shown to form beta-sheet structure, a high-resolution molecular structure is still unavailable to date. A search for a sequence neighbor using Abeta(10-42) as the query in the Protein Data-Bank (PDB) revealed that an RNA binding protein, AF-Sm1 from Archaeoglobus fulgidus (PDB entry: 1i4k chain Z), shared 36% identical residues. Using AF-Sm1 as a template, we built a molecular model of Abeta(10-42) by applying comparative modeling methods. The model of Abeta(10-42) contains an antiparallel beta-sheet formed by residues 16-23 and 32-41. Hydrophobic surface constituted by residues 17-20 (LVFF) separates distinctly charged regions. Residues that interact with RNA in the AF-Sm1 crystal structure were found to be conserved in Abeta. Using a native gel we demonstrate for the first time that RNA can interact with Abeta and selectively retard the formation of fibrils or higher-order oligomers. We hypothesize that in a similar fashion to AF-Sm1, RNA interacts with Abeta in the beta-hairpin (beta-turn-beta) structure and prevents fibril formation.
Collapse
|
43
|
Sabaté R, Estelrich J. Evidence of the Existence of Micelles in the Fibrillogenesis of β-Amyloid Peptide. J Phys Chem B 2005; 109:11027-32. [PMID: 16852343 DOI: 10.1021/jp050716m] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Alzheimer's disease (AD) is characterized by the deposition of fibrillar deposits formed by the amyloid beta (Abeta) peptide. The most widely accepted model of fibrillogenesis of Abeta affirms that fibrillogenesis occurs in two distinct stages, nucleation and elongation. A modification of the model includes the formation of micelles. We have demonstrated with accurate experimental determinations the existence of aggregates with micellar properties (namely, the critical micellar concentration, CMC, and aggregation number). Values of the CMC were obtained by analysis of surface tension (17.5 microM) and changes in the fluorescence of pyrene (17.6 microM), respectively. The average aggregation number determined by fluorescence quenching was 25, and it was independent of peptide concentration. The presence of micelles implies that above the CMC all excess peptide is incorporated into micelles, and consequently, the monomer concentration is kept almost constant. Thus, micelles act as a peptide reservoir. Micelles are located on-pathway, since they serves as nucleation centers. Experimental data support the model, since above 17.7 microM the time of half-aggregation is independent of peptide concentration, and the overall reaction of the conversion of monomer peptide into fibril can be treated as an apparent first-order reaction.
Collapse
Affiliation(s)
- Raimon Sabaté
- Departament de Fisicoquímica, Facultat de Farmàcia, Universitat de Barcelona, Avda. Joan XXIII s/n, 08028 Barcelona, Catalonia, Spain
| | | |
Collapse
|
44
|
Arimon M, Díez-Pérez I, Kogan MJ, Durany N, Giralt E, Sanz F, Fernàndez-Busquets X. Fine structure study of Abeta1-42 fibrillogenesis with atomic force microscopy. FASEB J 2005; 19:1344-6. [PMID: 15919759 DOI: 10.1096/fj.04-3137fje] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
One of the hallmarks of Alzheimer's disease is the self-aggregation of the amyloid beta peptide (Abeta) in extracellular amyloid fibrils. Among the different forms of Abeta, the 42-residue fragment (Abeta1-42) readily self-associates and forms nucleation centers from where fibrils can quickly grow. The strong tendency of Abeta1-42 to aggregate is one of the reasons for the scarcity of data on its fibril formation process. We have used atomic force microscopy (AFM) to visualize in liquid environment the fibrillogenesis of synthetic Abeta1-42 on hydrophilic and hydrophobic surfaces. The results presented provide nanometric resolution of the main structures characteristic of the several steps from monomeric Abeta1-42 to mature fibrils in vitro. Oligomeric globular aggregates of Abeta1-42 precede the appearance of protofibrils, the first fibrillar species, although we have not obtained direct evidence of oligomer-protofibril interconversion. The protofibril dimensions deduced from our AFM images are consistent with a model that postulates the stacking of the peptide in a hairpin conformation perpendicular to the long axis of the protofibril, forming single beta-sheets ribbon-shaped. The most abundant form of Abeta1-42 fibril exhibits a nodular structure with a ~100-nm periodicity. This length is very similar 1) to the length of protofibril bundles that are the dominant feature at earlier stages in the aggregation process, 2) to the period of helical structures that have been observed in the core of fibrils, and 3) to the distance between regularly spaced, structurally weak fibril points. Taken together, these data are consistent with the existence of a ~100-nm long basic protofibril unit that is a key fibril building block.
Collapse
Affiliation(s)
- Muriel Arimon
- Laboratori de Recerca en Nanobioenginyeria, Parc Científic de Barcelona (PCB), Universitat de Barcelona (UB), Spain
| | | | | | | | | | | | | |
Collapse
|
45
|
Chaney MO, Stine WB, Kokjohn TA, Kuo YM, Esh C, Rahman A, Luehrs DC, Schmidt AM, Stern D, Yan SD, Roher AE. RAGE and amyloid beta interactions: atomic force microscopy and molecular modeling. Biochim Biophys Acta Mol Basis Dis 2005; 1741:199-205. [PMID: 15882940 DOI: 10.1016/j.bbadis.2005.03.014] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2004] [Revised: 03/10/2005] [Accepted: 03/21/2005] [Indexed: 11/24/2022]
Abstract
In the AD brain, there are elevated amounts of soluble and insoluble Abeta peptides which enhance the expression of membrane bound and soluble receptor for advanced glycation end products (RAGE). The binding of soluble Abeta to soluble RAGE inhibits further aggregation of Abeta peptides, while membrane bound RAGE-Abeta interactions elicit activation of the NF-kappaB transcription factor promoting sustained chronic neuroinflammation. Atomic force microscopy observations demonstrated that the N-terminal domain of RAGE, by interacting with Abeta, is a powerful inhibitor of Abeta polymerization even at prolonged periods of incubation. Hence, the potential RAGE-Abeta structural interactions were further explored utilizing a series of computational chemistry algorithms. Our modeling suggests that a soluble dimeric RAGE assembly creates a positively charged well into which the negative charges of the N-terminal domain of dimeric Abeta dock.
Collapse
Affiliation(s)
- Michael O Chaney
- Department of Surgery, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
46
|
White JA, Manelli AM, Holmberg KH, Van Eldik LJ, Ladu MJ. Differential effects of oligomeric and fibrillar amyloid-β1–42 on astrocyte-mediated inflammation. Neurobiol Dis 2005; 18:459-65. [PMID: 15755672 DOI: 10.1016/j.nbd.2004.12.013] [Citation(s) in RCA: 164] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2004] [Revised: 10/19/2004] [Accepted: 12/22/2004] [Indexed: 12/31/2022] Open
Abstract
Activated glia, as a result of chronic inflammation, are associated with amyloid-beta peptide (Abeta) deposits in the brain of Alzheimer's disease (AD) patients. In vitro, glia are activated by Abeta inducing secretion of pro-inflammatory molecules. Recent studies have focused on soluble oligomers (or protofibrils) of Abeta as the toxic species in AD. In the present study, using rat astrocyte cultures, oligomeric Abeta induced initial high levels of IL-1beta decreasing over time and, in contrast, fibrillar Abeta increased IL-1beta levels over time. In addition, oligomeric Abeta, but not fibrillar Abeta, induced high levels of iNOS, NO, and TNF-alpha. Our results suggest that oligomers induced a profound, early inflammatory response, whereas fibrillar Abeta showed less increase of pro-inflammatory molecules, consistent with a more chronic form of inflammation.
Collapse
Affiliation(s)
- Jill A White
- Department of Medicine, Division of Geriatrics, Evanston Northwestern Healthcare Research Institute, Evanston, IL 60201, USA
| | | | | | | | | |
Collapse
|
47
|
Kellermayer MSZ, Grama L, Karsai A, Nagy A, Kahn A, Datki ZL, Penke B. Reversible Mechanical Unzipping of Amyloid β-Fibrils. J Biol Chem 2005; 280:8464-70. [PMID: 15596431 DOI: 10.1074/jbc.m411556200] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Amyloid fibrils are self-associating filamentous structures, the deposition of which is considered to be one of the most important factors in the pathogenesis of Alzheimer's disease and various other disorders. Here we used single molecule manipulation methods to explore the mechanics and structural dynamics of amyloid fibrils. In mechanically manipulated amyloid fibrils, formed from either amyloid beta (Abeta) peptides 1-40 or 25-35, beta-sheets behave as elastic structures that can be "unzipped" from the fibril with constant forces. The unzipping forces were different for Abeta1-40 and Abeta25-35. Unzipping was fully reversible across a wide range of stretch rates provided that coupling, via the beta-sheet, between bound and dissociated states was maintained. The rapid, cooperative zipping together of beta-sheets could be an important mechanism behind the self-assembly of amyloid fibrils. The repetitive force patterns contribute to a mechanical fingerprint that could be utilized in the characterization of different amyloid fibrils.
Collapse
Affiliation(s)
- Miklós S Z Kellermayer
- Department of Biophysics, University of Pécs, Faculty of Medicine, Pécs H-7624, Hungary.
| | | | | | | | | | | | | |
Collapse
|
48
|
Abstract
Transgenic mice over-expressing mutant human amyloid precursor protein have become an important tool for research on Alzheimer's disease (AD) and, in particular, for therapeutic screening. Many models have reported formation of amyloid plaques with age as is detected in AD. However, the plaques generated in transgenic mice are more soluble than human plaques. Differences in solubility may occur for a number of reasons; one proposal is the presence of murine Abeta peptides within the CNS milieu. Here, we report the interaction of human and murine Abeta peptides, Abeta40 and Abeta42, utilizing a fluorescence assay to monitor formation of mixed pre-fibrillar aggregates, electron microscopy to examine morphological characteristics and detergent solubility to monitor stability. Our results demonstrate that interspecies Abeta aggregates and fibres are readily formed and are more stable than homogenous human fibres. Furthermore, these results suggest that the presence of endogenous murine Abeta in human APP transgenic mice does not account for the increased solubility of plaques.
Collapse
Affiliation(s)
- Justin Fung
- Centre for Research in Neurodegenerative Diseases, Ontario Cancer Institute, Toronto, Ontario, Canada
| | | | | | | |
Collapse
|
49
|
Ghiso J, Shayo M, Calero M, Ng D, Tomidokoro Y, Gandy S, Rostagno A, Frangione B. Systemic catabolism of Alzheimer's Abeta40 and Abeta42. J Biol Chem 2004; 279:45897-908. [PMID: 15322125 DOI: 10.1074/jbc.m407668200] [Citation(s) in RCA: 134] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
To better understand the physiologic excretion and/or catabolism of circulating peripheral amyloid beta (Abeta), we labeled human Abeta40 (monomeric, with predominant unordered structure) and Abeta42 (mixture of monomers and oligomers in approximately 50:50 ratio, rich in beta-sheet conformation) with either Na(125)I or (125)I-tyramine cellobiose, also known as the cell-trapping ligand procedure, testing their blood clearance and organ uptake in B6SJLF1/J mice. Irrespective of the labeling protocol, the peptide conformation, and the degree of oligomerization, both Abeta40 and Abeta42 showed a short half-life of 2.5-3.0 min. The liver was the major organ responsible for plasma clearance, accounting for >60% of the peptide uptake, followed by the kidney. In vivo, hepatocytes captured >90% of the radiolabeled peptides which, after endocytosis, were preferentially catabolized and excreted into the bile. Biliary excretion of intact as well as partially degraded Abeta species became obviously relevant at doses above 10 microg. The use of biotin-labeled Abeta allowed the visualization of the interaction with HepG2 cells in culture, whereas competitive inhibition experiments with unlabeled Abeta demonstrated the specificity of the binding. The capability of the liver to uptake, catabolize, and excrete large doses of Abeta, several orders of magnitude above its physiologic concentration, may explain not only the femtomolar plasma levels of Abeta but the little fluctuation observed with age and disease stages.
Collapse
Affiliation(s)
- Jorge Ghiso
- Department of Pathology, New York University School of Medicine, New York, New York 10016, USA.
| | | | | | | | | | | | | | | |
Collapse
|
50
|
Päiviö A, Jarvet J, Gräslund A, Lannfelt L, Westlind-Danielsson A. Unique Physicochemical Profile of β-Amyloid Peptide Variant Aβ1–40E22G Protofibrils: Conceivable Neuropathogen in Arctic Mutant Carriers. J Mol Biol 2004; 339:145-59. [PMID: 15123427 DOI: 10.1016/j.jmb.2004.03.028] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2003] [Revised: 02/11/2004] [Accepted: 03/12/2004] [Indexed: 11/19/2022]
Abstract
A new early-onset form of Alzheimer's disease (AD) was described recently where a point mutation was discovered in codon 693 of the beta-amyloid (Abeta) precursor protein gene, the Arctic mutation. The mutation translates into a single amino acid substitution, glutamic acid-->glycine, in position 22 of the Abeta peptide. The mutation carriers have lower plasma levels of Abeta than normal, while in vitro studies show that Abeta1-40E22G protofibril formation is significantly enhanced. We have explored the nature of the Abeta1-40E22G peptide in more detail, in particular the protofibrils. Using size-exclusion chromatography (SEC) and circular dichroism spectroscopy (CD) kinetic and secondary structural characteristics were compared with other Abeta1-40 peptides and the Abeta12-28 fragment, all having single amino acid substitutions in position 22. We have found that Abeta1-40E22G protofibrils are a group of comparatively stabile beta-sheet-containing oligomers with a heterogeneous size distribution, ranging from >100 kDa to >3000 kDa. Small Abeta1-40E22G protofibrils are generated about 400 times faster than large ones. Salt promotes their formation, which significantly exceeds all the other peptides studied here, including the Dutch mutation Abeta1-40E22Q. Position 22 substitutions had significant effects on aggregation kinetics of Abeta1-40 and in Abeta12-28, although the qualitative aspects of the effects differed between the native peptide and the fragment, as no protofibrils were formed by the fragments. The rank order of protofibril formation of Abeta1-40 and its variants was the same as the rank order of the length of the nucleation/lag phase of the Abeta12-28 fragments, E22V>E22A?E22G>E22Q?E22, and correlated with the degree of hydrophobicity of the position 22 substituent. The molecular mass of peptide monomers and protofibrils were estimated better in SEC studies using linear rather than globular calibration standards. The characteristics of the Abeta1-40E22G suggest an important role for the peptide in the neuropathogenesis in the Arctic form of AD.
Collapse
Affiliation(s)
- A Päiviö
- Department of NEUROTEC, Geriatric Medicine, Karolinska Institutet, Novum KFC, SE-141 86 Huddinge, Sweden
| | | | | | | | | |
Collapse
|