1
|
Misiti F, Diotaiuti P, Lombardo GE, Tellone E. Sphingosine-1-phosphate Decreases Erythrocyte Dysfunction Induced by β-Amyloid. Int J Mol Sci 2024; 25:5184. [PMID: 38791223 PMCID: PMC11121638 DOI: 10.3390/ijms25105184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 04/28/2024] [Accepted: 05/08/2024] [Indexed: 05/26/2024] Open
Abstract
Amyloid beta peptides (Aβ) have been identified as the main pathogenic agents in Alzheimer's disease (AD). Soluble Aβ oligomers, rather than monomer or insoluble amyloid fibrils, show red blood cell (RBC) membrane-binding capacity and trigger several morphological and functional alterations in RBCs that can result in impaired oxygen transport and delivery. Since bioactive lipids have been recently proposed as potent protective agents against Aβ toxicity, we investigated the role of sphingosine-1-phosphate (S1P) in signaling pathways involved in the mechanism underlying ATP release in Ab-treated RBCs. In RBCs following different treatments, the ATP, 2,3 DPG and cAMP levels and caspase 3 activity were determined by spectrophotometric and immunoassay. S1P rescued the inhibition of ATP release from RBCs triggered by Ab, through a mechanism involving caspase-3 and restoring 2,3 DPG and cAMP levels within the cell. These findings reveal the molecular basis of S1P protection against Aβ in RBCs and suggest new therapeutic avenues in AD.
Collapse
Affiliation(s)
- Francesco Misiti
- Human Sciences, Social and Health Department, University of Cassino and Lazio Meridionale, V. S. Angelo, Loc. Folcara, 03043 Cassino, Italy;
| | - Pierluigi Diotaiuti
- Human Sciences, Social and Health Department, University of Cassino and Lazio Meridionale, V. S. Angelo, Loc. Folcara, 03043 Cassino, Italy;
| | - Giovanni Enrico Lombardo
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno d’Alcontres 31, 98166 Messina, Italy; (G.E.L.); (E.T.)
| | - Ester Tellone
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno d’Alcontres 31, 98166 Messina, Italy; (G.E.L.); (E.T.)
| |
Collapse
|
2
|
Kim YM, Park S, Choi SY, Oh SB, Jung M, Pack CG, Hwang JJ, Tak E, Lee JY. Clusterin Binding Modulates the Aggregation and Neurotoxicity of Amyloid-β(1-42). Mol Neurobiol 2022; 59:6228-6244. [PMID: 35904715 DOI: 10.1007/s12035-022-02973-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 07/20/2022] [Indexed: 11/28/2022]
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disorder characterized by the accumulation of amyloid-β (Aβ) aggregates in the brain. Clusterin (CLU), also known as apolipoprotein J, is a potent risk factor associated with AD pathogenesis, in which Aβ aggregation is essentially involved. We observed close colocalization of CLU and Aβ(1-42) (Aβ42) in parenchymal amyloid plaques or vascular amyloid deposits in the brains of human amyloid precursor protein (hAPP)-transgenic Tg2576 mice. Therefore, to elucidate the binding interaction between CLU and Aβ42 and its impact on amyloid aggregation and toxicity, the two synthetic proteins were incubated together under physiological conditions, and their structural and morphological variations were investigated using biochemical, biophysical, and microscopic analyses. Synthetic CLU spontaneously bound to different possible variants of Aβ42 aggregates with very high affinity (Kd = 2.647 nM) in vitro to form solid CLU-Aβ42 complexes. This CLU binding prevented further aggregation of Aβ42 into larger oligomers or fibrils, enriching the population of smaller Aβ42 oligomers and protofibrils and monomers. CLU either alleviated or augmented Aβ42-induced cytotoxicity and apoptosis in the neuroblastoma-derived SH-SY5Y and N2a cells, depending on the incubation period and the molar ratio of CLU:Aβ42 involved in the reaction before addition to the cells. Thus, the effects of CLU on Aβ42-induced cytotoxicity were likely determined by the extent to which it bound and sequestered toxic Aβ42 oligomers or protofibrils. These findings suggest that CLU could influence amyloid neurotoxicity and pathogenesis by modulating Aβ aggregation.
Collapse
Affiliation(s)
- Yun-Mi Kim
- Department of Medical Science, Asan Medical Institute of Convergence Science and Technology, University of Ulsan College of Medicine, Seoul, 05505, Republic of Korea.,Asan Institute for Life Sciences, Asan Medical Center, Seoul, 05505, Republic of Korea
| | - SuJi Park
- Asan Institute for Life Sciences, Asan Medical Center, Seoul, 05505, Republic of Korea
| | - Su Yeon Choi
- Department of Medical Science, Asan Medical Institute of Convergence Science and Technology, University of Ulsan College of Medicine, Seoul, 05505, Republic of Korea.,Asan Institute for Life Sciences, Asan Medical Center, Seoul, 05505, Republic of Korea
| | - Shin Bi Oh
- Asan Institute for Life Sciences, Asan Medical Center, Seoul, 05505, Republic of Korea
| | - MinKyo Jung
- Asan Institute for Life Sciences, Asan Medical Center, Seoul, 05505, Republic of Korea
| | - Chan-Gi Pack
- Asan Institute for Life Sciences, Asan Medical Center, Seoul, 05505, Republic of Korea.,Department of Convergence Medicine, University of Ulsan College of Medicine, Seoul, 05505, Republic of Korea
| | - Jung Jin Hwang
- Asan Institute for Life Sciences, Asan Medical Center, Seoul, 05505, Republic of Korea
| | - Eunyoung Tak
- Asan Institute for Life Sciences, Asan Medical Center, Seoul, 05505, Republic of Korea.,Department of Convergence Medicine, University of Ulsan College of Medicine, Seoul, 05505, Republic of Korea
| | - Joo-Yong Lee
- Asan Institute for Life Sciences, Asan Medical Center, Seoul, 05505, Republic of Korea. .,Department of Convergence Medicine, University of Ulsan College of Medicine, Seoul, 05505, Republic of Korea.
| |
Collapse
|
3
|
Oamen HP, Romero Romero N, Knuckles P, Saarikangas J, Radman‐Livaja M, Dong Y, Caudron F. A rare natural lipid induces neuroglobin expression to prevent amyloid oligomers toxicity and retinal neurodegeneration. Aging Cell 2022; 21:e13645. [PMID: 35656861 PMCID: PMC9282837 DOI: 10.1111/acel.13645] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 03/10/2022] [Accepted: 05/10/2022] [Indexed: 11/29/2022] Open
Abstract
Most neurodegenerative diseases such as Alzheimer's disease are proteinopathies linked to the toxicity of amyloid oligomers. Treatments to delay or cure these diseases are lacking. Using budding yeast, we report that the natural lipid tripentadecanoin induces expression of the nitric oxide oxidoreductase Yhb1 to prevent the formation of protein aggregates during aging and extends replicative lifespan. In mammals, tripentadecanoin induces expression of the Yhb1 orthologue, neuroglobin, to protect neurons against amyloid toxicity. Tripentadecanoin also rescues photoreceptors in a mouse model of retinal degeneration and retinal ganglion cells in a Rhesus monkey model of optic atrophy. Together, we propose that tripentadecanoin affects p-bodies to induce neuroglobin expression and offers a potential treatment for proteinopathies and retinal neurodegeneration.
Collapse
Affiliation(s)
- Henry Patrick Oamen
- School of Biological and Behavioural SciencesQueen Mary University of LondonLondonUK
| | - Nathaly Romero Romero
- School of Biological and Behavioural SciencesQueen Mary University of LondonLondonUK
| | - Philip Knuckles
- Friedrich Miescher Institute for Biomedical ResearchBaselSwitzerland
| | - Juha Saarikangas
- Helsinki Institute of Life Science, HiLIFE, University of HelsinkiHelsinkiFinland
- Research Programme in Molecular and Integrative Biosciences, Faculty of Biological and Environmental SciencesUniversity of HelsinkiHelsinkiFinland
- Neuroscience Center, University of HelsinkiHelsinkiFinland
| | | | | | | |
Collapse
|
4
|
Rochais C, Lecoutey C, Hamidouche K, Giannoni P, Gaven F, Cem E, Mignani S, Baranger K, Freret T, Bockaert J, Rivera S, Boulouard M, Dallemagne P, Claeysen S. Donecopride, a Swiss army knife with potential against Alzheimer's disease. Br J Pharmacol 2020; 177:1988-2005. [PMID: 31881553 DOI: 10.1111/bph.14964] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 10/21/2019] [Accepted: 11/28/2019] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND AND PURPOSE We recently identified donecopride as a pleiotropic compound able to inhibit AChE and to activate 5-HT4 receptors. Here, we have assessed the potential therapeutic effects of donecopride in treating Alzheimer's disease (AD). EXPERIMENTAL APPROACH We used two in vivo animal models of AD, transgenic 5XFAD mice and mice exposed to soluble amyloid-β peptides and, in vitro, primary cultures of rat hippocampal neurons. Pro-cognitive and anti-amnesic effects were evaluated with novel object recognition, Y-maze, and Morris water maze tests. Amyloid load in mouse brain was measured ex vivo and effects of soluble amyloid-β peptides on neuronal survival and neurite formation determined in vitro. KEY RESULTS In vivo, chronic (3 months) administration of donecopride displayed potent anti-amnesic properties in the two mouse models of AD, preserving learning capacities, including working and long-term spatial memories. These behavioural effects were accompanied by decreased amyloid aggregation in the brain of 5XFAD mice and, in cultures of rat hippocampal neurons, reduced tau hyperphosphorylation. In vitro, donecopride increased survival in neuronal cultures exposed to soluble amyloid-β peptides, improved the neurite network and provided neurotrophic benefits, expressed as the formation of new synapses. CONCLUSIONS AND IMPLICATIONS Donecopride acts like a Swiss army knife, exhibiting a range of sustainable symptomatic therapeutic effects and potential disease-modifying effects in models of AD. Clinical trials with this promising drug candidate will soon be undertaken to confirm its therapeutic potential in humans.
Collapse
Affiliation(s)
- Christophe Rochais
- Normandie Univ, Caen, France.,UNICAEN, CERMN (Centre d'Etudes et de Recherche sur le Médicament de Normandie), Caen, France
| | - Cédric Lecoutey
- Normandie Univ, Caen, France.,UNICAEN, CERMN (Centre d'Etudes et de Recherche sur le Médicament de Normandie), Caen, France
| | - Katia Hamidouche
- Normandie Univ, Caen, France.,UNICAEN, INSERM U1075 COMETE, Caen, France
| | - Patrizia Giannoni
- IGF, Univ Montpellier, CNRS, INSERM, Montpellier, France.,Equipe Chrome, EA7352, Université de Nîmes, Nîmes, France
| | - Florence Gaven
- IGF, Univ Montpellier, CNRS, INSERM, Montpellier, France.,CRBM, CNRS UMR5237, Montpellier, France
| | - Eleazere Cem
- IGF, Univ Montpellier, CNRS, INSERM, Montpellier, France
| | - Serge Mignani
- Normandie Univ, Caen, France.,UNICAEN, CERMN (Centre d'Etudes et de Recherche sur le Médicament de Normandie), Caen, France
| | - Kevin Baranger
- Aix-Marseille Univ, CNRS, INP, Inst Neurophysiopathol, Marseille, France
| | - Thomas Freret
- Normandie Univ, Caen, France.,UNICAEN, INSERM U1075 COMETE, Caen, France
| | - Joël Bockaert
- IGF, Univ Montpellier, CNRS, INSERM, Montpellier, France
| | - Santiago Rivera
- Aix-Marseille Univ, CNRS, INP, Inst Neurophysiopathol, Marseille, France
| | - Michel Boulouard
- Normandie Univ, Caen, France.,UNICAEN, INSERM U1075 COMETE, Caen, France
| | - Patrick Dallemagne
- Normandie Univ, Caen, France.,UNICAEN, CERMN (Centre d'Etudes et de Recherche sur le Médicament de Normandie), Caen, France
| | | |
Collapse
|
5
|
Detection/quantification of amyloid aggregation in solution using the novel fluorescent benzofuranone-derivative compounds as amyloid fluorescent probes: synthesis and in vitro characterization. JOURNAL OF THE IRANIAN CHEMICAL SOCIETY 2019. [DOI: 10.1007/s13738-019-01599-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
|
6
|
Gomi F, Uchida Y, Endo S. Up-regulation of NSP3 by Oligomeric Aβ Accelerates Neuronal Death Through Cas-independent Rap1A Activation. Neuroscience 2018; 386:182-193. [PMID: 29966723 DOI: 10.1016/j.neuroscience.2018.06.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 06/20/2018] [Accepted: 06/21/2018] [Indexed: 11/17/2022]
Abstract
β-Amyloid (Aβ) plays an important role in the early pathogenesis of Alzheimer's disease (AD). In vitro studies have demonstrated that Aβ oligomers induce hippocampal and neocortical neuronal death. However the neurotoxic mechanisms by which soluble Aβ oligomers cause neuronal damage and death remain to be fully elucidated. To this end, we analyzed the gene expression profile of rat cerebral cortical neurons treated with Aβ oligomers in vitro. Aβ treatment induced the expression of novel SH2-containing protein 3 (NSP3), an adaptor molecule interacting with Cas family proteins. NSP3 expression was upregulated not only in oligomeric-Aβ-treated cultured neurons but also in the neocortex of aged Tg2576 mice. NSP3 overexpression in cultured cortical neurons accelerated neuronal death. The C-terminal region of NSP3 unbound to a Cas protein was necessary for the NSP3-induced acceleration of neuronal death, as was Cas-independent Rap1A activation downstream of NSP3. Moreover, NSP3 RNAi knockdown partially rescued Aβ-oligomer-treated neurons. These results indicate that NSP3 upregulation by soluble Aβ oligomers may accelerate neuronal death via Cas-independent Rap1A activation, implicating NSP3 in the pathogenesis of AD.
Collapse
Affiliation(s)
- Fujiya Gomi
- Tokyo Metropolitan Institute of Gerontology, 35-2 Sakaecho, Itabashi-ku, Tokyo 173-0015, Japan.
| | - Yoko Uchida
- Tokyo Metropolitan Institute of Gerontology, 35-2 Sakaecho, Itabashi-ku, Tokyo 173-0015, Japan
| | - Shogo Endo
- Tokyo Metropolitan Institute of Gerontology, 35-2 Sakaecho, Itabashi-ku, Tokyo 173-0015, Japan.
| |
Collapse
|
7
|
McGillewie L, Ramesh M, Soliman ME. Sequence, Structural Analysis and Metrics to Define the Unique Dynamic Features of the Flap Regions Among Aspartic Proteases. Protein J 2017; 36:385-396. [PMID: 28762197 DOI: 10.1007/s10930-017-9735-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Aspartic proteases are a class of hydrolytic enzymes that have been implicated in a number of diseases such as HIV, malaria, cancer and Alzheimer's. The flap region of aspartic proteases is a characteristic unique structural feature of these enzymes; and found to have a profound impact on protein overall structure, function and dynamics. Flap dynamics also plays a crucial role in drug binding and drug resistance. Therefore, understanding the structure and dynamic behavior of this flap regions is crucial in the design of potent and selective inhibitors against aspartic proteases. Defining metrics that can describe the flap motion/dynamics has been a challenging topic in literature. This review is the first attempt to compile comprehensive information on sequence, structure, motion and metrics used to assess the dynamics of the flap region of different aspartic proteases in "one pot". We believe that this review would be of critical importance to the researchers from different scientific domains.
Collapse
Affiliation(s)
- Lara McGillewie
- Molecular Modelling & Drug Design Research Group, School of Health Sciences, University of KwaZulu-Natal (UKZN), Westville, Durban, 4001, South Africa
| | - Muthusamy Ramesh
- Molecular Modelling & Drug Design Research Group, School of Health Sciences, University of KwaZulu-Natal (UKZN), Westville, Durban, 4001, South Africa
| | - Mahmoud E Soliman
- Molecular Modelling & Drug Design Research Group, School of Health Sciences, University of KwaZulu-Natal (UKZN), Westville, Durban, 4001, South Africa.
| |
Collapse
|
8
|
Dorard E, Chasseigneaux S, Gorisse-Hussonnois L, Broussard C, Pillot T, Allinquant B. Soluble Amyloid Precursor Protein Alpha Interacts with alpha3-Na, K-ATPAse to Induce Axonal Outgrowth but Not Neuroprotection: Evidence for Distinct Mechanisms Underlying these Properties. Mol Neurobiol 2017; 55:5594-5610. [PMID: 28983842 DOI: 10.1007/s12035-017-0783-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 09/20/2017] [Indexed: 01/09/2023]
Abstract
Amyloid precursor protein (APP) is cleaved not only to generate the amyloid peptide (Aß), involved in neurodegenerative processes, but can also be metabolized by alpha secretase to produce and release soluble N-terminal APP (sAPPα), which has many properties including the induction of axonal elongation and neuroprotection. The mechanisms underlying the properties of sAPPα are not known. Here, we used proteomic analysis of mouse cortico-hippocampal membranes to identify the neuronal specific alpha3 (α3)-subunit of the plasma membrane enzyme Na, K-ATPase (NKA) as a new binding partner of sAPPα. We showed that sAPPα recruits very rapidly clusters of α3-NKA at neuronal surface, and its binding triggers a cascade of events promoting sAPPα-induced axonal outgrowth. The binding of sAPPα with α3-NKA was not observed for sAPPα-induced Aß1-42 oligomers neuroprotection, neither the downstream events particularly the interaction of sAPPα with APP before endocytosis, ERK signaling, and the translocation of SET from the nucleus to the plasma membrane. These data suggest that the mechanisms of the axonal growth promoting and neuroprotective properties of sAPPα appear to be specific and independent. The signals at the cell surface specific to trigger these mechanisms require further study.
Collapse
Affiliation(s)
- Emilie Dorard
- UMR_S894 INSERM, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, 75014, Paris, France.,SynAging, 54500, Vandoeuvre-les, Nancy, France
| | - Stéphanie Chasseigneaux
- UMR_S894 INSERM, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, 75014, Paris, France.,INSERM U1144, Université Paris Descartes and Université Paris Diderot UMR-S 1144, 75006, Paris, France
| | - Lucie Gorisse-Hussonnois
- UMR_S894 INSERM, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, 75014, Paris, France
| | - Cédric Broussard
- Plate-forme Protéomique, Université Paris Descartes 3P5, Institut Cochin, 75014, Paris, France
| | | | - Bernadette Allinquant
- UMR_S894 INSERM, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, 75014, Paris, France.
| |
Collapse
|
9
|
Yamin G, Coppola G, Teplow DB. Design, Characterization, and Use of a Novel Amyloid β-Protein Control for Assembly, Neurotoxicity, and Gene Expression Studies. Biochemistry 2016; 55:5049-60. [PMID: 27505174 DOI: 10.1021/acs.biochem.6b00579] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
A key pathogenic agent in Alzheimer's disease (AD) is the amyloid β-protein (Aβ), which self-assembles into a variety of neurotoxic structures. Establishing structure-activity relationships for these assemblies, which is critical for proper therapeutic target identification and design, requires aggregation and neurotoxicity experiments that are properly controlled with respect to the Aβ peptide itself. "Reverse" Aβ or non-Aβ peptides suffer from the fact that their biophysical properties are too similar or dissimilar, respectively, to those of native Aβ for them to be appropriate controls. For this reason, we used simple protein design principles to create scrambled Aβ peptides predicted to behave distinctly from native Aβ. We showed that our prediction was true by monitoring secondary structure dynamics with thioflavin T fluorescence and circular dichroism spectroscopy, determining oligomer size distributions, and assaying neurotoxic activity. We then demonstrated the utility of the scrambled Aβ peptides by using them to control experiments examining the effects of Aβ monomers, dimers, higher-order oligomers, and fibrils on gene expression in primary rat hippocampal neurons. Significant changes in gene expression were observed for all peptide assemblies, but fibrils induced the largest changes. Weighted gene co-expression network analysis revealed two predominant gene modules related to Aβ treatment. Many genes within these modules were associated with inflammatory signaling pathways.
Collapse
Affiliation(s)
- Ghiam Yamin
- Department of Radiology, University of California San Diego School of Medicine , La Jolla, California 92093, United States.,Department of Neurology, David Geffen School of Medicine at UCLA , Los Angeles, California 90095, United States
| | - Giovanni Coppola
- Department of Neurology, David Geffen School of Medicine at UCLA , Los Angeles, California 90095, United States.,Department of Psychiatry and Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine at UCLA , Los Angeles, California 90095, United States
| | - David B Teplow
- Department of Neurology, David Geffen School of Medicine at UCLA , Los Angeles, California 90095, United States
| |
Collapse
|
10
|
Benterud T, Pankratov L, Solberg R, Bolstad N, Skinningsrud A, Baumbusch L, Sandvik L, Saugstad OD. Perinatal Asphyxia May Influence the Level of Beta-Amyloid (1-42) in Cerebrospinal Fluid: An Experimental Study on Newborn Pigs. PLoS One 2015; 10:e0140966. [PMID: 26501201 PMCID: PMC4621034 DOI: 10.1371/journal.pone.0140966] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 08/20/2015] [Indexed: 12/15/2022] Open
Abstract
OBJECTIVE Total tau (T-tau), phosphorylated tau (p-Tau) and Beta-Amyloid 1-42 (AB42) in Cerebrospinal Fluid (CSF) are useful biomarkers in neurodegenerative diseases. The aim of the study was to investigate the role of these and other CSF biomarkers (T-tau, p-Tau, AB42, S100B and NSE), during hypoxia-reoxygenation in a newborn pig model. DESIGN Thirty newborn pigs were included in a study of moderate or severe hypoxia. The moderate hypoxia group (n = 12) was exposed to global hypoxia (8% O2) until Base excess (BE) reached -15 mmol/l. The pigs in the group exposed to severe hypoxia (n = 12) received 8% O2 until BE reached -20 mmol/l or mean Blood Pressure fell below 20 mm Hg, The control group (n = 6) was kept at room air. For all treatments, the CSF was collected at 9.5 hours after the intervention. RESULTS The level of AB42 in CSF was significantly lower in the pigs exposed to severe hypoxia compared with the control group, 922(SD +/-445)pg/ml versus. 1290(SD +/-143) pg/ml (p<0.05), respectively. Further, a non-significant reduction of AB42 was observed in the group exposed to moderate hypoxia T-tau and p-Tau revealed no significant differences between the intervention groups and the control group, however a significantly higher level of S100B was seen in the CSF of pigs receiving hypoxia in comparison to the level in the control group. Further on, there was a moderate negative correlation between the levels of AB42 and S100B in CSF, as well as a moderate negative correlation between Lactate in blood at end of hypoxia and AB42 in CSF. INTERPRETATION This is the first study to our knowledge that demonstrated a significant drop in AB42 in CSF after neonatal hypoxia. Whether or not this has an etiological basis for adult neurodegenerative disorders needs to be studied with additional experiments and epidemiological studies. AB42 and S100B are significantly changed in neonatal pigs subjected to hypoxia compared to controls and thus may be valuable biomarkers of perinatal asphyxia.
Collapse
Affiliation(s)
- Torkil Benterud
- Dept of Pediatric Research, Oslo University Hospital, Oslo, Norway
- * E-mail: ;
| | - Leonid Pankratov
- Dept of Pediatric Research, Oslo University Hospital, Oslo, Norway
| | - Rønnaug Solberg
- Dept of Pediatric Research, Oslo University Hospital, Oslo, Norway
| | - Nils Bolstad
- Dept of Medical Biochemistry, Oslo University Hospital, Oslo, Norway
| | - Anders Skinningsrud
- Dept Multidisciplinary Lab Med & Med Biochem, Akershus Univ Hosp, Lørenskog, Norway
| | - Lars Baumbusch
- Dept of Pediatric Research, Oslo University Hospital, Oslo, Norway
| | - Leiv Sandvik
- Dept of Biostatistics and Epidemiology, Oslo University Hospital, Oslo, Norway
| | | |
Collapse
|
11
|
Elnar AA, Allouche A, Desor F, Yen FT, Soulimani R, Oster T. Lactational exposure of mice to low levels of non-dioxin-like polychlorinated biphenyls increases susceptibility to neuronal stress at a mature age. Neurotoxicology 2015; 53:314-320. [PMID: 26480858 DOI: 10.1016/j.neuro.2015.10.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2015] [Accepted: 10/05/2015] [Indexed: 11/27/2022]
Abstract
Lactational exposure to low levels of the sum of the six indicator polychlorinated biphenyls (Σ6 NDL-PCBs, 10ng/kg/day) is known to lead to persistent anxious behavior in young and adult offspring mice at postnatal days 40 and 160, respectively. At more advanced life stages, we evaluated the effects on the mouse brain of neuronal stress induced by the synaptotoxic amyloid-beta (Aβ) peptide. Perinatal exposure of lactating mice to Σ6 NDL-PCBs did not affect short-term memory performances of their offspring male mice aged 14 months as compared to control PCB-naive mice. However, following intracerebroventricular injection of soluble Aβ oligomers, significant impairments in long-term memory were detected in the mice that had been lactationally treated with Σ6 NDL-PCBs. In addition, immunoblot analyses of the synaptosomal fraction of hippocampal tissues from treated mice revealed a lower expression of the synaptic proteins synaptophysin and PSD-95. Though preliminary, our findings suggest for the first time that early exposure to low levels of NDL-PCBs induce late neuronal vulnerability to amyloid stress. Additional experiments are needed to confirm whether early environmental influences are involved in the etiology of brain aging and cognitive decline.
Collapse
Affiliation(s)
- Arpiné Ardzivian Elnar
- Neurotoxicologie Alimentaire et Bioactivité, MRCA, BP 4102, 57040 Metz, France; Université de Lorraine, Unité de Recherche Animal et Fonctionnalités des Produits Animaux (UR AFPA), EA3998, INRA USC 0340, France.
| | - Ahmad Allouche
- Biodisponibilité et Fonctionnalités des Lipides Alimentaires, BFLA, ENSAIA, Avenue de la forêt de Haye, 54500 Vandœuvre-lès-Nancy, France; Université de Lorraine, Unité de Recherche Animal et Fonctionnalités des Produits Animaux (UR AFPA), EA3998, INRA USC 0340, France
| | - Frédéric Desor
- Neurotoxicologie Alimentaire et Bioactivité, MRCA, BP 4102, 57040 Metz, France; Université de Lorraine, Unité de Recherche Animal et Fonctionnalités des Produits Animaux (UR AFPA), EA3998, INRA USC 0340, France
| | - Frances T Yen
- Biodisponibilité et Fonctionnalités des Lipides Alimentaires, BFLA, ENSAIA, Avenue de la forêt de Haye, 54500 Vandœuvre-lès-Nancy, France; Université de Lorraine, Unité de Recherche Animal et Fonctionnalités des Produits Animaux (UR AFPA), EA3998, INRA USC 0340, France
| | - Rachid Soulimani
- Neurotoxicologie Alimentaire et Bioactivité, MRCA, BP 4102, 57040 Metz, France; Université de Lorraine, Unité de Recherche Animal et Fonctionnalités des Produits Animaux (UR AFPA), EA3998, INRA USC 0340, France
| | - Thierry Oster
- Biodisponibilité et Fonctionnalités des Lipides Alimentaires, BFLA, ENSAIA, Avenue de la forêt de Haye, 54500 Vandœuvre-lès-Nancy, France; Université de Lorraine, Unité de Recherche Animal et Fonctionnalités des Produits Animaux (UR AFPA), EA3998, INRA USC 0340, France
| |
Collapse
|
12
|
Chen CH, Li W, Sultana R, You MH, Kondo A, Shahpasand K, Kim BM, Luo ML, Nechama M, Lin YM, Yao Y, Lee TH, Zhou XZ, Swomley AM, Butterfield DA, Zhang Y, Lu KP. Pin1 cysteine-113 oxidation inhibits its catalytic activity and cellular function in Alzheimer's disease. Neurobiol Dis 2015; 76:13-23. [PMID: 25576397 DOI: 10.1016/j.nbd.2014.12.027] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Revised: 12/02/2014] [Accepted: 12/26/2014] [Indexed: 12/23/2022] Open
Abstract
The unique proline isomerase Pin1 is pivotal for protecting against age-dependent neurodegeneration in Alzheimer's disease (AD), with its inhibition providing a molecular link between tangle and plaque pathologies. Pin1 is oxidatively modified in human AD brains, but little is known about its regulatory mechanisms and pathological significance of such Pin1 modification. In this paper, our determination of crystal structures of oxidized Pin1 reveals a series of Pin1 oxidative modifications on Cys113 in a sequential fashion. Cys113 oxidization is further confirmed by generating antibodies specifically recognizing oxidized Cys113 of Pin1. Furthermore, Pin1 oxidation on Cys113 inactivates its catalytic activity in vitro, and Ala point substitution of Cys113 inactivates the ability of Pin1 to isomerize tau as well as to promote protein turnover of tau and APP. Moreover, redox regulation affects Pin1 subcellular localization and Pin1-mediated neuronal survival in response to hypoxia treatment. Importantly, Cys113-oxidized Pin1 is significantly increased in human AD brain comparing to age-matched controls. These results not only identify a novel Pin1 oxidation site to be the critical catalytic residue Cys113, but also provide a novel oxidative regulation mechanism for inhibiting Pin1 activity in AD. These results suggest that preventing Pin1 oxidization might help to reduce the risk of AD.
Collapse
Affiliation(s)
- Chun-Hau Chen
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Wenzong Li
- Dept. of Molecular Biosciences and Institute for Cellular and Molecular Biology, University of Texas, Austin, TX 78712, USA
| | - Rukhsana Sultana
- Department of Chemistry, University of Kentucky, Lexington, KY 40506, USA
| | - Mi-Hyeon You
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Asami Kondo
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Koorosh Shahpasand
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Byeong Mo Kim
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Man-Li Luo
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Morris Nechama
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Yu-Min Lin
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Yandan Yao
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Tae Ho Lee
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Xiao Zhen Zhou
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Aaron M Swomley
- Department of Chemistry, University of Kentucky, Lexington, KY 40506, USA
| | - D Allan Butterfield
- Department of Chemistry, University of Kentucky, Lexington, KY 40506, USA; Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40506, USA; Center of Membrane Sciences, University of Kentucky, Lexington, KY 40506, USA.
| | - Yan Zhang
- Dept. of Molecular Biosciences and Institute for Cellular and Molecular Biology, University of Texas, Austin, TX 78712, USA.
| | - Kun Ping Lu
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA; Institute for Translational Medicine, Fujian Medical University, Fuzhou 350108, China.
| |
Collapse
|
13
|
Barman A, Prabhakar R. Computational Insights into Substrate and Site Specificities, Catalytic Mechanism, and Protonation States of the Catalytic Asp Dyad of β -Secretase. SCIENTIFICA 2014; 2014:598728. [PMID: 25309776 PMCID: PMC4189502 DOI: 10.1155/2014/598728] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 06/21/2014] [Indexed: 06/04/2023]
Abstract
In this review, information regarding substrate and site specificities, catalytic mechanism, and protonation states of the catalytic Asp dyad of β-secretase (BACE1) derived from computational studies has been discussed. BACE1 catalyzes the rate-limiting step in the generation of Alzheimer amyloid beta peptide through the proteolytic cleavage of the amyloid precursor protein. Due to its biological functioning, this enzyme has been considered as one of the most important targets for finding the cure for Alzheimer's disease. Molecular dynamics (MD) simulations suggested that structural differences in the key regions (inserts A, D, and F and the 10s loop) of the enzyme are responsible for the observed difference in its activities towards the WT- and SW-substrates. The modifications in the flap, third strand, and insert F regions were found to be involved in the alteration in the site specificity of the glycosylphosphatidylinositol bound form of BACE1. Our QM and QM/MM calculations suggested that BACE1 hydrolyzed the SW-substrate more efficiently than the WT-substrate and that cleavage of the peptide bond occurred in the rate-determining step. The results from molecular docking studies showed that the information concerning a single protonation state of the Asp dyad is not enough to run an in silico screening campaign.
Collapse
Affiliation(s)
- Arghya Barman
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, FL 33146, USA
| | - Rajeev Prabhakar
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, FL 33146, USA
| |
Collapse
|
14
|
Sagy-Bross C, Hadad N, Levy R. Cytosolic phospholipase A2α upregulation mediates apoptotic neuronal death induced by aggregated amyloid-β peptide1-42. Neurochem Int 2013; 63:541-50. [PMID: 24044897 DOI: 10.1016/j.neuint.2013.09.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Revised: 09/01/2013] [Accepted: 09/06/2013] [Indexed: 10/26/2022]
Abstract
Increased cytosolic phospholipase A2α (cPLA2α) immunoreactivity and transcript were observed in Alzheimer's disease (AD) brain associated with amyloid deposits. Thus, the present study examined whether cPLA2α upregulation participate in cortical neuron damage induced by aggregated Aβ1-42 and determined its role in the signaling events leading to damage, using an antisense technology. Exposure of primary cortical neurons to 1μM aggregated Aβ1-42 for 24h induced up-regulation and activation of cPLA2α and apoptotic cell death of about 30% as detected by: cell count, MTT reduction, caspases-3 and -8 activation, DAPI and TUNEL staining, that were prevented by inhibition of cPLA2α up-regulation and activity in the presence of antisense against cPLA2α (AS). cPLA2α was rapidly activated upon addition of aggregated Aβ1-42, as determined by its phosphorylated form on serine 505, and this activity was dependent on NADPH oxidase activity. NOX2- and NOX4-NADPH oxidase upregulation at 24h of aggregated Aβ1-42 exposure was not affected by the presence of AS, but superoxide production was reduced, probably due to NOX2 inhibition. cPLA2α upregulation led to activation of neutral sphingomyelinase (N-SMase) as its activity was inhibited in the presence of AS, and could be restored by addition of arachidonic acid. Addition of ceramide analog induced caspase-8 activation leading to caspase-3 activation and apoptotic neuronal death. In conclusion, our results suggest that cPLA2α activity plays a crucial role in the signaling cascade leading to apoptotic neuronal death by aggregated Aβ1-42 probably via activation of N-SMase, ceramide production and caspases-3 and -8.
Collapse
Affiliation(s)
- Chen Sagy-Bross
- Immunology and Infectious Diseases Laboratory, Clinical Biochemistry Department, Faculty of Health Sciences, Ben-Gurion University of the Negev, Soroka University Medical Center, Beer-Sheva, Israel
| | - Nurit Hadad
- Immunology and Infectious Diseases Laboratory, Clinical Biochemistry Department, Faculty of Health Sciences, Ben-Gurion University of the Negev, Soroka University Medical Center, Beer-Sheva, Israel
| | - Rachel Levy
- Immunology and Infectious Diseases Laboratory, Clinical Biochemistry Department, Faculty of Health Sciences, Ben-Gurion University of the Negev, Soroka University Medical Center, Beer-Sheva, Israel.
| |
Collapse
|
15
|
N-truncated Abeta starting with position four: early intraneuronal accumulation and rescue of toxicity using NT4X-167, a novel monoclonal antibody. Acta Neuropathol Commun 2013; 1:56. [PMID: 24252153 PMCID: PMC3893517 DOI: 10.1186/2051-5960-1-56] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Accepted: 08/10/2013] [Indexed: 12/27/2022] Open
Abstract
Background The amyloid hypothesis in Alzheimer disease (AD) considers amyloid β peptide (Aβ) deposition causative in triggering down-stream events like neurofibrillary tangles, cell loss, vascular damage and memory decline. In the past years N-truncated Aβ peptides especially N-truncated pyroglutamate AβpE3-42 have been extensively studied. Together with full-length Aβ1–42 and Aβ1–40, N-truncated AβpE3-42 and Aβ4–42 are major variants in AD brain. Although Aβ4–42 has been known for a much longer time, there is a lack of studies addressing the question whether AβpE3-42 or Aβ4–42 may precede the other in Alzheimer’s disease pathology. Results Using different Aβ antibodies specific for the different N-termini of N-truncated Aβ, we discovered that Aβ4-x preceded AβpE3-x intraneuronal accumulation in a transgenic mouse model for AD prior to plaque formation. The novel Aβ4-x immunoreactive antibody NT4X-167 detected high molecular weight aggregates derived from N-truncated Aβ species. While NT4X-167 significantly rescued Aβ4–42 toxicity in vitro no beneficial effect was observed against Aβ1–42 or AβpE3-42 toxicity. Phenylalanine at position four of Aβ was imperative for antibody binding, because its replacement with alanine or proline completely prevented binding. Although amyloid plaques were observed using NT4X-167 in 5XFAD transgenic mice, it barely reacted with plaques in the brain of sporadic AD patients and familial cases with the Arctic, Swedish and the presenilin-1 PS1Δ9 mutation. A consistent staining was observed in blood vessels in all AD cases with cerebral amyloid angiopathy. There was no cross-reactivity with other aggregates typical for other common neurodegenerative diseases showing that NT4X-167 staining is specific for AD. Conclusions Aβ4-x precedes AβpE3-x in the well accepted 5XFAD AD mouse model underlining the significance of N-truncated species in AD pathology. NT4X-167 therefore is the first antibody reacting with Aβ4-x and represents a novel tool in Alzheimer research.
Collapse
|
16
|
Bouter Y, Dietrich K, Wittnam JL, Rezaei-Ghaleh N, Pillot T, Papot-Couturier S, Lefebvre T, Sprenger F, Wirths O, Zweckstetter M, Bayer TA. N-truncated amyloid β (Aβ) 4-42 forms stable aggregates and induces acute and long-lasting behavioral deficits. Acta Neuropathol 2013; 126:189-205. [PMID: 23685882 PMCID: PMC3722453 DOI: 10.1007/s00401-013-1129-2] [Citation(s) in RCA: 134] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 05/08/2013] [Accepted: 05/09/2013] [Indexed: 12/30/2022]
Abstract
N-truncated Aβ4-42 is highly abundant in Alzheimer disease (AD) brain and was the first Aβ peptide discovered in AD plaques. However, a possible role in AD aetiology has largely been neglected. In the present report, we demonstrate that Aβ4-42 rapidly forms aggregates possessing a high aggregation propensity in terms of monomer consumption and oligomer formation. Short-term treatment of primary cortical neurons indicated that Aβ4-42 is as toxic as pyroglutamate Aβ3-42 and Aβ1-42. In line with these findings, treatment of wildtype mice using intraventricular Aβ injection induced significant working memory deficits with Aβ4-42, pyroglutamate Aβ3-42 and Aβ1-42. Transgenic mice expressing Aβ4-42 (Tg4-42 transgenic line) developed a massive CA1 pyramidal neuron loss in the hippocampus. The hippocampus-specific expression of Aβ4-42 correlates well with age-dependent spatial reference memory deficits assessed by the Morris water maze test. Our findings indicate that N-truncated Aβ4-42 triggers acute and long-lasting behavioral deficits comparable to AD typical memory dysfunction.
Collapse
Affiliation(s)
- Yvonne Bouter
- Division of Molecular Psychiatry, Georg-August-University Goettingen, University Medicine Goettingen, von-Siebold-Strasse 5, 37075 Goettingen, Germany
| | - Katharina Dietrich
- Division of Molecular Psychiatry, Georg-August-University Goettingen, University Medicine Goettingen, von-Siebold-Strasse 5, 37075 Goettingen, Germany
| | - Jessica L. Wittnam
- Division of Molecular Psychiatry, Georg-August-University Goettingen, University Medicine Goettingen, von-Siebold-Strasse 5, 37075 Goettingen, Germany
| | - Nasrollah Rezaei-Ghaleh
- Department for NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, 37077 Goettingen, Germany
| | | | | | | | - Frederick Sprenger
- Division of Molecular Psychiatry, Georg-August-University Goettingen, University Medicine Goettingen, von-Siebold-Strasse 5, 37075 Goettingen, Germany
| | - Oliver Wirths
- Division of Molecular Psychiatry, Georg-August-University Goettingen, University Medicine Goettingen, von-Siebold-Strasse 5, 37075 Goettingen, Germany
| | - Markus Zweckstetter
- German Center for Neurodegenerative Diseases (DZNE), 37077 Göttingen, Germany
- Department for NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, 37077 Goettingen, Germany
| | - Thomas A. Bayer
- Division of Molecular Psychiatry, Georg-August-University Goettingen, University Medicine Goettingen, von-Siebold-Strasse 5, 37075 Goettingen, Germany
| |
Collapse
|
17
|
|
18
|
Barman A, Prabhakar R. Elucidating the catalytic mechanism of β-secretase (BACE1): a quantum mechanics/molecular mechanics (QM/MM) approach. J Mol Graph Model 2013; 40:1-9. [PMID: 23337572 DOI: 10.1016/j.jmgm.2012.12.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Revised: 12/04/2012] [Accepted: 12/17/2012] [Indexed: 12/18/2022]
Abstract
In this quantum mechanics/molecular mechanics (QM/MM) study, the mechanisms of the hydrolytic cleavage of the Met2-Asp3 and Leu2-Asp3 peptide bonds of the amyloid precursor protein (WT-substrate) and its Swedish mutant (SW) respectively catalyzed by β-secretase (BACE1) have been investigated by explicitly including the electrostatic and steric effects of the protein environment in the calculations. BACE1 catalyzes the rate-determining step in the generation of Alzheimer amyloid beta peptides and is widely acknowledged as a promising therapeutic target. The general acid-base mechanism followed by the enzyme proceeds through the following two steps: (1) formation of the gem-diol intermediate and (2) cleavage of the peptide bond. The formation of the gem-diol intermediate occurs with the barriers of 19.6 and 16.1 kcal/mol for the WT- and SW-substrate respectively. The QM/MM energetics predict that with the barriers of 21.9 and 17.2 kcal/mol for the WT- and SW-substrate respectively the cleavage of the peptide bond occurs in the rate-determining step. The computed barriers are in excellent agreement with the measured barrier of ∼18.0 kcal/mol for the SW-substrate and in line with the experimental observation that the cleavage of this substrate is sixty times more efficient than the WT-substrate.
Collapse
Affiliation(s)
- Arghya Barman
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, FL 33146, USA
| | | |
Collapse
|
19
|
The association between prion proteins and Aβ₁₋₄₂ oligomers in cytotoxicity and apoptosis. Biochem Biophys Res Commun 2012; 424:214-20. [PMID: 22743555 DOI: 10.1016/j.bbrc.2012.06.056] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Accepted: 06/12/2012] [Indexed: 01/20/2023]
Abstract
Misfolding of prion protein (PrP to PrPSc) can cause neurodegenerative prion diseases. As a glycosylphosphatidylinositol (GPI)-anchored membrane protein, the normal form of PrP (PrPC) can function as a receptor for ligands in the extracellular space. PrPC was suggested to be involved in memory, synaptic neuronal communication, and anti-oxidation as a neuroprotective agent. The recently identified interaction between PrPC and Aβ(1-42) oligomers suggested another role for PrP as a receptor for Aβ(1-42) oligomers, thereby influencing cytotoxicity and apoptosis. Here, the association between PrPC and Aβ(1-42) oligomers was investigated by visualizing protein localization in neuronal cells by immunocytochemistry. Aβ(1-42) oligomer-induced cytotoxicity was tested in respective expressions of PrPC by using mouse neuroblastoma-2a (N2a) cells, the prion protein overexpressed cells (L2-2B1), and a Prnp-null mouse hippocampal cell line (HpL 3-4). Moreover, apoptotic proteins such as caspase-8 were used to assess the effect of PrPC on Aβ(1-42) oligomer-mediated apoptosis. In L2-2B1 and HpL 3-4 cells, the difference in the cytotoxicity of Aβ(1-42) oligomers could be clearly distinguished. In addition, Aβ(1-42) oligomers induced mitochondria dysfunction, reactive oxygen species (ROS) generation, and calcium influx PrPC-dependently. Apoptosis, related to mitochondria dysfunction, was further investigated to determine the cytotoxic pathway; the results suggest that PrPC could be involved in both the intrinsic and extrinsic apoptotic pathways. Finally, cells with abundant PrPC expression seemed to be more susceptible to Aβ(1-42) oligomer toxicity, suggesting the importance of the level of PrPC expression in the induction of apoptosis.
Collapse
|
20
|
Barman A, Prabhakar R. Protonation states of the catalytic dyad of β-secretase (BACE1) in the presence of chemically diverse inhibitors: a molecular docking study. J Chem Inf Model 2012; 52:1275-87. [PMID: 22545704 DOI: 10.1021/ci200611t] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In this molecular docking study, the protonation states of the catalytic Asp dyad of the beta-secretase (BACE1) enzyme in the presence of eight chemically diverse inhibitors have been predicted. BACE1 catalyzes the rate-determining step in the generation of Alzheimer amyloid beta peptides and is widely considered as a promising therapeutic target. All the inhibitors were redocked into their corresponding X-ray structures using a combination of eight different protonation states of the Asp dyad for each inhibitor. Five inhibitors were primarily found to favor two different monoprotonated states, and the remaining three favor a dideprotonated state. In addition, five of them exhibited secondary preference for a diprotonated state. These results show that the knowledge of a single protonation state of the Asp dyad is not sufficient to search for the novel inhibitors of BACE1 and the most plausible state for each inhibitor must be determined prior to conducting in-silico screening.
Collapse
Affiliation(s)
- Arghya Barman
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida 33146, USA
| | | |
Collapse
|
21
|
Zhu X, Bora RP, Barman A, Singh R, Prabhakar R. Dimerization of the Full-Length Alzheimer Amyloid β-Peptide (Aβ42) in Explicit Aqueous Solution: A Molecular Dynamics Study. J Phys Chem B 2012; 116:4405-16. [DOI: 10.1021/jp210019h] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Xiaoxia Zhu
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida 33146,
United States
| | - Ram Prasad Bora
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida 33146,
United States
| | - Arghya Barman
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida 33146,
United States
| | - Rajiv Singh
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida 33146,
United States
| | - Rajeev Prabhakar
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida 33146,
United States
| |
Collapse
|
22
|
Ohta H, Arai S, Akita K, Ohta T, Fukuda S. Effects of NK-4 in a transgenic mouse model of Alzheimer's disease. PLoS One 2012; 7:e30007. [PMID: 22238689 PMCID: PMC3251615 DOI: 10.1371/journal.pone.0030007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Accepted: 12/09/2011] [Indexed: 11/18/2022] Open
Abstract
Beta-amyloid (Aβ) peptides are considered to play a major role in the pathogenesis of Alzheimer's disease (AD) and molecules that can prevent pathways of Aβ toxicity may be potential therapeutic agents for treatment of AD. We have previously reported that NK-4, a cyanine photosensitizing dye, displays neurotrophic and antioxidant activities. In this study, we report the effects of NK-4 on the toxicity of Aβ and on cognitive function and Aβ concentration in a transgenic mouse model of AD (Tg2576). In vitro, NK-4 effectively protected neuronal cells from toxicity induced by Aβ. In addition, it displayed profound inhibitory activities on Aβ fibril formation. In vivo, Tg2576 mice received an intraperitoneal injection at 100 or 500 µg/kg of NK-4 once a day, five times a week for 9 months. Administration of NK-4 to the mice attenuated impairment of recognition memory, associative memory, and learning ability, as assessed by a novel object recognition test, a passive avoidance test, and a water maze test, respectively. NK-4 decreased the brain Aβ concentration while increasing the plasma amyloid level in a dose-dependent manner. NK-4 also improved memory impairments of ICR mice induced by direct intracerebroventricular administration of Aβ. These lines of evidence suggest that NK-4 may affect multiple pathways of amyloid pathogenesis and could be useful for treatment of AD.
Collapse
Affiliation(s)
- Hitomi Ohta
- Research Center, Hayashibara Biochemical Laboratories, Inc., Okayama, Japan.
| | | | | | | | | |
Collapse
|
23
|
Desbène C, Malaplate-Armand C, Youssef I, Garcia P, Stenger C, Sauvée M, Fischer N, Rimet D, Koziel V, Escanyé MC, Oster T, Kriem B, Yen FT, Pillot T, Olivier JL. Critical role of cPLA2 in Aβ oligomer-induced neurodegeneration and memory deficit. Neurobiol Aging 2011; 33:1123.e17-29. [PMID: 22188721 DOI: 10.1016/j.neurobiolaging.2011.11.008] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2010] [Revised: 11/03/2011] [Accepted: 11/04/2011] [Indexed: 12/23/2022]
Abstract
Soluble beta-amyloid (Aβ) oligomers are considered to putatively play a critical role in the early synapse loss and cognitive impairment observed in Alzheimer's disease. We previously demonstrated that Aβ oligomers activate cytosolic phospholipase A(2) (cPLA(2)), which specifically releases arachidonic acid from membrane phospholipids. We here observed that cPLA(2) gene inactivation prevented the alterations of cognitive abilities and the reduction of hippocampal synaptic markers levels noticed upon a single intracerebroventricular injection of Aβ oligomers in wild type mice. We further demonstrated that the Aβ oligomer-induced sphingomyelinase activation was suppressed and that phosphorylation of Akt/protein kinase B (PKB) was preserved in neuronal cells isolated from cPLA(2)(-/-) mice. Interestingly, expression of the Aβ precursor protein (APP) was reduced in hippocampus homogenates and neuronal cells from cPLA(2)(-/-) mice, but the relationship with the resistance of these mice to the Aβ oligomer toxicity requires further investigation. These results therefore show that cPLA(2) plays a key role in the Aβ oligomer-associated neurodegeneration, and as such represents a potential therapeutic target for the treatment of Alzheimer's disease.
Collapse
Affiliation(s)
- Cédric Desbène
- Lipidomix (EA 4422), INPL-ENSAIA, Université de Lorraine, Vandœuvre-lès-Nancy, France
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Legleiter J, Fryer JD, Holtzman DM, Kowalewski T. The modulating effect of mechanical changes in lipid bilayers caused by apoE-containing lipoproteins on Aβ induced membrane disruption. ACS Chem Neurosci 2011; 2:588-599. [PMID: 22125665 DOI: 10.1021/cn2000475] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
A major feature of Alzheimer's disease (AD), a late-onset neurodegenerative disorder, is the ordered aggregation of the β-amyloid peptide (Aβ) into fibrils that comprise extracellular neuritic plaques found in the disease brain. One of many potential pathways for Aβ toxicity may be modulation of lipid membrane function. Here, we show by in situ atomic force microscopy (AFM) that astrocyte secreted lipoprotein particles (ASLPs) containing different isoforms of apolipoprotein E (apoE), of which the apoE4 allele is a major risk factor for the development of AD, can protect total brain lipid extract bilayers from Aβ(1-40) induced disruption. The apoE4 allele was less effective in protecting lipid bilayers from disruption compared with apoE3. Size analysis of apoE-containing ASLPs and mechanical studies of bilayer properties revealed that apoE-containing ASLPs modulate the mechanical properties of bilayers by acquiring some bilayer components (most likely cholesterol and/or oxidatively damaged lipids). Measurement of bilayer mechanical properties was accomplished with scanning probe acceleration microscopy (SPAM). These measurements demonstrated that apoE4 was also less effective in modulating mechanical properties of bilayers in comparison with apoE3. This ability of apoE to alter the mechanical properties of lipid membranes may represent a potential mechanism for the suppression of Aβ(1-40) induced bilayer disruption.
Collapse
Affiliation(s)
- Justin Legleiter
- The C. Eugene Bennett Department of Chemistry, WVnano Initiative, the Center for Neurosciences, West Virginia University, 217 Clark Hall, P.O. Box 6045, Morgantown, West Virginia 26506, United States
| | - John D. Fryer
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - David M. Holtzman
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri 63110, United States
- Hope Center for Neurological Disorders, Washington University School of Medicine, 660 South Euclid Avenue, Box 8111, St. Louis, Missouri 63110, United States
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Tomasz Kowalewski
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| |
Collapse
|
25
|
Barman A, Schürer S, Prabhakar R. Computational modeling of substrate specificity and catalysis of the β-secretase (BACE1) enzyme. Biochemistry 2011; 50:4337-49. [PMID: 21500768 DOI: 10.1021/bi200081h] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
In this combined MD simulation and DFT study, interactions of the wild-type (WT) amyloid precursor protein (APP) and its Swedish variant (SW), Lys670 → Asn and Met671 → Leu, with the beta-secretase (BACE1) enzyme and their cleavage mechanisms have been investigated. BACE1 catalyzes the rate-limiting step in the generation of 40-42 amino acid long Alzheimer amyloid beta (Aβ) peptides. All key structural parameters such as position of the flap, volume of the active site, electrostatic binding energy, structures, and positions of the inserts A, D, and F and 10s loop obtained from the MD simulations show that, in comparison to the WT-substrate, BACE1 exhibits greater affinity for the SW-substrate and orients it in a more reactive conformation. The enzyme-substrate models derived from the MD simulations were further utilized to investigate the general acid/base mechanism used by BACE1 to hydrolytically cleave these substrates. This mechanism proceeds through the following two steps: (1) formation of the gem-diol intermediate and (2) cleavage of the peptide bond. For the WT-substrate, the overall barrier of 22.4 kcal/mol for formation of the gem-diol intermediate is 3.3 kcal/mol higher than for the SW-substrate (19.1 kcal/mol). This process is found to be the rate-limiting in the entire mechanism. The computed barrier is in agreement with the measured barrier of ca. 18.00 kcal/mol for the WT-substrate and supports the experimental observation that the cleavage of the SW-substrate is 60 times more efficient than the WT-substrate.
Collapse
Affiliation(s)
- Arghya Barman
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, FL 33146, USA
| | | | | |
Collapse
|
26
|
Bora RP, Prabhakar R. Translational, rotational and internal dynamics of amyloid beta-peptides (Abeta40 and Abeta42) from molecular dynamics simulations. J Chem Phys 2010; 131:155103. [PMID: 20568886 DOI: 10.1063/1.3249609] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
In this study, diffusion constants [translational (D(T)) and rotational (D(R))], correlation times [rotational (tau(rot)) and internal (tau(int))], and the intramolecular order parameters (S(2)) of the Alzheimer amyloid-beta peptides Abeta40 and Abeta42 have been calculated from 150 ns molecular dynamics simulations in aqueous solution. The computed parameters have been compared with the experimentally measured values. The calculated D(T) of 1.61 x 10(-6) cm(2)/s and 1.43 x 10(-6) cm(2)/s for Abeta40 and Abeta42, respectively, at 300 K was found to follow the correct trend defined by the Debye-Stokes-Einstein relation that its value should decrease with the increase in the molecular weight. The estimated D(R) for Abeta40 and Abeta42 at 300 K are 0.085 and 0.071 ns(-1), respectively. The rotational (C(rot)(t)) and internal (C(int)(t)) correlation functions of Abeta40 and Abeta42 were observed to decay at nano- and picosecond time scales, respectively. The significantly different time decays of these functions validate the factorization of the total correlation function (C(tot)(t)) of Abeta peptides into C(rot)(t) and C(int)(t). At both short and long time scales, the Clore-Szabo model that was used as C(int)(t) provided the best behavior of C(tot)(t) for both Abeta40 and Abeta42. In addition, an effective rotational correlation time of Abeta40 is also computed at 18 degrees C and the computed value (2.30 ns) is in close agreement with the experimental value of 2.45 ns. The computed S(2) parameters for the central hydrophobic core, the loop region, and C-terminal domains of Abeta40 and Abeta42 are in accord with the previous studies.
Collapse
Affiliation(s)
- Ram Prasad Bora
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida 33146, USA
| | | |
Collapse
|
27
|
Ciliary neurotrophic factor cell-based delivery prevents synaptic impairment and improves memory in mouse models of Alzheimer's disease. J Neurosci 2010; 30:7516-27. [PMID: 20519526 DOI: 10.1523/jneurosci.4182-09.2010] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The development of novel therapeutic strategies for Alzheimer's disease (AD) represents one of the biggest unmet medical needs today. Application of neurotrophic factors able to modulate neuronal survival and synaptic connectivity is a promising therapeutic approach for AD. We aimed to determine whether the loco-regional delivery of ciliary neurotrophic factor (CNTF) could prevent amyloid-beta (Abeta) oligomer-induced synaptic damages and associated cognitive impairments that typify AD. To ensure long-term administration of CNTF in the brain, we used recombinant cells secreting CNTF encapsulated in alginate polymers. The implantation of these bioreactors in the brain of Abeta oligomer-infused mice led to a continuous secretion of recombinant CNTF and was associated with the robust improvement of cognitive performances. Most importantly, CNTF led to full recovery of cognitive functions associated with the stabilization of synaptic protein levels in the Tg2576 AD mouse model. In vitro as well as in vivo, CNTF activated a Janus kinase/signal transducer and activator of transcription-mediated survival pathway that prevented synaptic and neuronal degeneration. These preclinical studies suggest that CNTF and/or CNTF receptor-associated pathways may have AD-modifying activity through protection against progressive Abeta-related memory deficits. Our data also encourage additional exploration of ex vivo gene transfer for the prevention and/or treatment of AD.
Collapse
|
28
|
Yang EJ, Kim SI, Ku HY, Lee DS, Lee JW, Kim YS, Seong YH, Song KS. Syringin from stem bark of Fraxinus rhynchophylla protects Aβ(25–35)-induced toxicity in neuronal cells. Arch Pharm Res 2010; 33:531-8. [DOI: 10.1007/s12272-010-0406-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2009] [Revised: 01/19/2010] [Accepted: 02/05/2010] [Indexed: 01/03/2023]
|
29
|
Bora RP, Prabhakar R. Elucidation of Interactions of Alzheimer Amyloid β Peptides (Aβ40 and Aβ42) with Insulin Degrading Enzyme: A Molecular Dynamics Study. Biochemistry 2010; 49:3947-56. [DOI: 10.1021/bi1002103] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Ram Prasad Bora
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida 33146
| | - Rajeev Prabhakar
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida 33146
| |
Collapse
|
30
|
Shaykhalishahi H, Taghizadeh M, Yazdanparast R, Chang YT. Anti-amyloidogenic effect of AA3E2 attenuates beta-amyloid induced toxicity in SK-N-MC cells. Chem Biol Interact 2010; 186:16-23. [PMID: 20359466 DOI: 10.1016/j.cbi.2010.03.042] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2010] [Revised: 03/14/2010] [Accepted: 03/23/2010] [Indexed: 02/07/2023]
Abstract
Beta-amyloid peptide (Abeta) is believed to play a recognized role in pathogenesis of Alzheimer's disease (AD). Self-association of Abeta peptide into amyloid fibrils causes neurotoxicity. Compounds capable of interfering with Abeta-Abeta interaction through binding to nucleation sites can inhibit Abeta amyloidogenesis and Abeta-induced cytotoxicity. AA3E2 is a triazine-derivative whose anti-amyloidogenic ability has previously been established. In the present study, we evaluated the protective effect of AA3E3 against Abeta(1-42)-induced toxicity in SK-N-MC cell line. The cell exposure to the co-incubated Abeta(1-42) with AA3E2 decreased the cell viability loss dose-dependently, compared to cells exposed to Abeta(1-42) fibrils. Co-incubation with AA3E2 also attenuated the ROS production, activation of caspase-3 and the extent of apoptotic cell death induced by Abeta(1-42) fibril. Moreover, the 3D structure of the molecular associates between Abeta(1-42) and AA3E2 were theoretically determined by docking studies. Our docking data indicated that AA3E2 inhibits the formation of Abeta fibril likely via binding to the nucleation site within the hydrophobic region of Abeta (KLVFF). These observations provide the background for future design of more elegant beta-breaking agents for dissolution of Abeta fibrillar aggregates.
Collapse
Affiliation(s)
- Hamed Shaykhalishahi
- Institute of Biochemistry and Biophysics,University of Tehran, Enghelab Ave., Tehran, Iran
| | | | | | | |
Collapse
|
31
|
Nitrous oxide plus isoflurane induces apoptosis and increases beta-amyloid protein levels. Anesthesiology 2010; 111:741-52. [PMID: 19741497 DOI: 10.1097/aln.0b013e3181b27fd4] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Some anesthetics have been suggested to induce neurotoxicity, including promotion of Alzheimer's disease neuropathogenesis. Nitrous oxide and isoflurane are common anesthetics. The authors set out to assess the effects of nitrous oxide and/or isoflurane on apoptosis and beta-amyloid (Abeta) levels in H4 human neuroglioma cells and primary neurons from naïve mice. METHODS The cells or neurons were exposed to 70% nitrous oxide and/or 1% isoflurane for 6 h. The cells or neurons and conditioned media were harvested at the end of the treatment. Caspase-3 activation, apoptosis, processing of amyloid precursor protein, and Abeta levels were determined. RESULTS Treatment with a combination of 70% nitrous oxide and 1% isoflurane for 6 h induced caspase-3 activation and apoptosis in H4 naïve cells and primary neurons from naïve mice. The 70% nitrous oxide plus 1% isoflurane, but neither alone, for 6 h induced caspase-3 activation and apoptosis, and increased levels of beta-site amyloid precursor protein-cleaving enzyme and Abeta in H4-amyloid precursor protein cells. In addition, the nitrous oxide plus isoflurane-induced Abeta generation was reduced by a broad caspase inhibitor, Z-VAD. Finally, the nitrous oxide plus isoflurane-induced caspase-3 activation was attenuated by gamma-secretase inhibitor L-685,458, but potentiated by exogenously added Abeta. CONCLUSION These results suggest that the common anesthetics nitrous oxide plus isoflurane may promote neurotoxicity by inducing apoptosis and increasing Abeta levels. The generated Abeta may further potentiate apoptosis to form another round of apoptosis and Abeta generation. More studies, especially the in vivo confirmation of these in vitro findings, are needed.
Collapse
|
32
|
Cell-derived soluble oligomers of human amyloid-β peptides disturb cellular homeostasis and induce apoptosis in primary hippocampal neurons. J Neural Transm (Vienna) 2009; 116:1561-9. [DOI: 10.1007/s00702-009-0311-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2009] [Accepted: 09/04/2009] [Indexed: 12/30/2022]
|
33
|
Ravault S, Flore C, Saurel O, Milon A, Brasseur R, Lins L. Study of the specific lipid binding properties of Abeta 11-22 fragment at endosomal pH. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:10948-10953. [PMID: 19735146 DOI: 10.1021/la901544g] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Increasing evidence implicates interactions between Abeta peptide and lipids in the development of Alzheimer's disease. More generally, Abeta peptide interactions with membranes seem to depend on the composition of the lipid bilayer and the structural features of the peptide. One key parameter should be pH, since one site of intracellular Abeta peptide production and/or accumulation is likely to be endosomes. This intracellular endosomal accumulation was suggested to contribute to disease progression. In this paper, we report a study on the 11-22 amphiphilic domain of Abeta in interaction with model membrane; this region contains most of the charged residues of the N-terminal domain of Abeta. We show that the peptide charge, and more precisely the protonation state of histidines 13 and/or 14, is important for the interaction with lipids. Hence, it is only at endosomal pH that a conformational change of the peptide is observed in the presence of negatively charged lipid vesicles, that is, when both lipid headgroups and histidines can interact through electrostatic interactions. Specific interactions of the fragment with phosphatidylserine and to a lesser extent with phosphatidylcholine, but not phosphatidylethanolamine, are further evidenced by the Langmuir monolayer technique. From our results, we suggest that the protonation state of His residues could have a role in the pathogenic surface interaction of the whole Abeta peptide with membranes.
Collapse
Affiliation(s)
- S Ravault
- Centre de Biophysique Moléculaire Numérique, Agricultural University of Gembloux, 5030 Gembloux, Belgium
| | | | | | | | | | | |
Collapse
|
34
|
Barman A, Taves W, Prabhakar R. Insights into the mechanism of methionine oxidation catalyzed by metal (Cu(2+), Zn(2+), and Fe(3+)) - amyloid beta (Abeta) peptide complexes: A computational study. J Comput Chem 2009; 30:1405-13. [PMID: 19037857 DOI: 10.1002/jcc.21167] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
In this DFT study, a mechanism of the oxidation of methionine (Met) amino acid residue catalyzed by the metal (Cu(2+), Zn(2+), and Fe(3+)) bound amyloid beta (Abeta) peptide has been proposed. Based on experimental information, two different mechanisms: (1) stepwise and (2) concerted mechanisms for this important process have been investigated. The B3LYP calculations suggest that in the stepwise mechanism, the two separate pathways leading to the same sulfoxide product [Met(O)] go through prohibitively high barriers of 27.3 and 35.1 kcal/mol, therefore it is ruled out. In the concerted mechanism, the Cu(2+)-Abeta complex has been found to be the most efficient catalyst with the computed barrier of 14.3 kcal/mol. The substitutions of Cu(2+) by Zn(2+) and Fe(3+) increase barriers to 19.6 and 16.9 kcal/mol, respectively and make the reaction thermodynamically less favorable. It was also found that, in comparison with the cysteine (Cys) residue, Met is more susceptible toward oxidation. Its substitution with Cys slightly increased the barrier to 15.8 kcal/mol for the Cu(2+)-Abeta complex.
Collapse
Affiliation(s)
- Arghya Barman
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida 33146, USA
| | | | | |
Collapse
|
35
|
Yazdanparast R, Shaykhalishahi H. Protective effect of a triazine-derivative (AA3E2) on beta-amyloid-induced damages in SK-N-MC cells. Toxicol In Vitro 2009; 23:1277-83. [PMID: 19631265 DOI: 10.1016/j.tiv.2009.07.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2009] [Revised: 06/24/2009] [Accepted: 07/17/2009] [Indexed: 01/29/2023]
Abstract
The role of beta-amyloid (A beta) in the pathogenesis of Alzheimer's disease (AD) is frequently reported in the literature. Though the exact mode of action is not known, it is suggested that A beta induces cell death through induction of oxidative stress possibly through hydrogen peroxide generation. In that case, antioxidants should be capable of attenuating the A beta-induced cytotoxicities. In that regard, we evaluated the effect(s) of a triazine-derivative, AA3E2, with established antioxidant activity. Pretreatment of SK-N-MC neuroblastoma cells with AA3E2, followed by exposure to A beta(1-42) showed 28.3% higher viability relative to the control cells which has not been treated with AA3E2. In addition, AA3E2 inhibited caspase-3 activation caused by A beta(1-42) and it attenuated A beta(1-42)-induced intracellular ROS (reactive oxygen species) accumulation. The lower level of intracellular free radicals was further confirmed by higher and lower activities of intracellular catalase and superoxide dismutase, respectively. These observations, parallel to the literature data, reconfirm the oxidative stress disrupting role of A beta(1-42) peptide. Thus, sequestration of this role by potential antioxidants such as AA3E2 might happen to be a suitable strategy for future treatments of AD.
Collapse
Affiliation(s)
- Razieh Yazdanparast
- Institute of Biochemistry and Biophysics, University of Tehran, P.O. Box 13145-1384, Tehran, Iran.
| | | |
Collapse
|
36
|
Smith PES, Brender JR, Ramamoorthy A. Induction of negative curvature as a mechanism of cell toxicity by amyloidogenic peptides: the case of islet amyloid polypeptide. J Am Chem Soc 2009; 131:4470-8. [PMID: 19278224 PMCID: PMC2665920 DOI: 10.1021/ja809002a] [Citation(s) in RCA: 124] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The death of insulin-producing beta-cells is a key step in the pathogenesis of type 2 diabetes. The amyloidogenic peptide Islet Amyloid Polypeptide (IAPP, also known as amylin) has been shown to disrupt beta-cell membranes leading to beta-cell death. Despite the strong evidence linking IAPP to the destruction of beta-cell membrane integrity and cell death, the mechanism of IAPP toxicity is poorly understood. In particular, the effect of IAPP on the bilayer structure has largely been uncharacterized. In this study, we have determined the effect of the amyloidogenic and toxic hIAPP(1-37) peptide and the nontoxic and nonamyloidogenic rIAPP(1-37) peptide on membranes by a combination of DSC and solid-state NMR spectroscopy. We also characterized the toxic but largely nonamyloidogenic rIAPP(1-19) and hIAPP(1-19) fragments. DSC shows that both amyloidogenic (hIAPP(1-37)) and largely nonamyloidogenic (hIAPP(1-19) and rIAPP(1-19)) toxic versions of the peptide strongly favor the formation of negative curvature in lipid bilayers, while the nontoxic full-length rat IAPP(1-37) peptide does not. This result was confirmed by solid-state NMR spectroscopy which shows that in bicelles composed of regions of high curvature and low curvature, nontoxic rIAPP(1-37) binds to the regions of low curvature while toxic rIAPP(1-19) binds to regions of high curvature. Similarly, solid-state NMR spectroscopy shows that the toxic rIAPP(1-19) peptide significantly disrupts the lipid bilayer structure, whereas the nontoxic rIAPP(1-37) does not have a significant effect. These results indicate IAPP may induce the formation of pores by the induction of excess membrane curvature and can be used to guide the design of compounds that can prevent the cell-toxicity of IAPP. This mechanism may be important to understand the toxicity of other amyloidogenic proteins. Our solid-state NMR results also demonstrate the possibility of using bicelles to measure the affinity of biomolecules for negatively or positively curved regions of the membrane, which we believe will be useful in a variety of biochemical and biophysical investigations related to the cell membrane.
Collapse
Affiliation(s)
- Pieter E S Smith
- Biophysics and Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, USA
| | | | | |
Collapse
|
37
|
Melino S, Nepravishta R, Bellomaria A, Di Marco S, Paci M. Nucleic acid binding of the RTN1-C C-terminal region: toward the functional role of a reticulon protein. Biochemistry 2009; 48:242-53. [PMID: 19140693 DOI: 10.1021/bi801407w] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
RTN1-C protein is a membrane protein localized in the ER and expressed in the nervous system. Its biological role is still unclear, although interactions of the N-terminal region of RTN1-C with proteins involved in vesicle trafficking have been observed, but the role of the C-terminal region of this family protein remains to be investigated. By a homology analysis of the amino acid sequence, we identified in the C-terminal region of RTN1-C a unique consensus sequence characteristic of H4 histone protein. Thus, a 23-mer peptide (RTN1-C(CT)) corresponding to residues 186-208 of RTN1-C was synthesized, and its conformation and its interaction with nucleic acids were investigated. Here we demonstrate the strong ability of RTN1-C(CT) peptide to bind and condense the nucleic acids using electrophoretic and spectroscopic techniques. To determine if the binding of RTN1-C to nucleic acids could be regulated in vivo by an acetylation-deacetylation mechanism, as for the histone proteins, we studied the interaction of RTN1-C with one zinc-dependent histone deacetylase (HDAC) enzyme, HDAC8, with fluorescence and kinetic techniques using an acetylated form of RTN1-C(CT). The results reported here allow us to propose that the nucleic acid binding property of RTN1-C may have an important role in the biological function of this protein, the function of which could be regulated by an acetylation-deacetylation mechanism.
Collapse
Affiliation(s)
- Sonia Melino
- Department of Sciences and Chemical Technologies, University of Rome Tor Vergata, Rome, Italy.
| | | | | | | | | |
Collapse
|
38
|
Zhang L, Yu H, Song C, Lin X, Chen B, Tan C, Cao G, Wang Z. Expression, purification, and characterization of recombinant human beta-amyloid42 peptide in Escherichia coli. Protein Expr Purif 2008; 64:55-62. [PMID: 18996484 DOI: 10.1016/j.pep.2008.10.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2008] [Revised: 10/10/2008] [Accepted: 10/10/2008] [Indexed: 10/21/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by a progressive loss of cognitive function. Evidence indicates that abnormal processing and extracellular deposition of the beta-amyloid42 peptide, the longer form of proteolytic derivative of the transmembrane glycoprotein-amyloid precursor protein (APP), is a key step in the pathogenesis of AD. Since it is convenient and economical to obtain such a peptide biologically, in this study, we report for the first time a method to express in E. coli and purify beta-amyloid42 using glutathione-S-transferase (GST) fusion system. beta-Amyloid42 gene was inserted into a vector pGEX-4T-1 to construct a GST-fusion protein. The fusion protein GST-beta-amyloid42, expressed in BL21 (DE3) strain, was purified with GSH-affinity chromatography followed by thrombin cleavage. The digested product was further purified with an additional GSH-affinity and a Benzamidine chromatography step. After cleavage and purification, the beta-amyloid42 moiety showed the expected size of 4.5 kDa on Tricine-SDS-PAGE, and was further confirmed by Western blot. Moreover, the fibrillar recombinant beta-amyloid42 exhibited great aggregation activity and showed neurotoxicity on neuron cells in vitro. These results suggest that our method will be useful in obtaining a large quantity of recombinant beta-amyloid42 peptide for further physiological and biochemical studies.
Collapse
Affiliation(s)
- Li Zhang
- Jiangsu Institute of Nuclear Medicine, Key Laboratory of Nuclear Medicine, Ministry of Health, Wuxi, Jiangsu 214063, China
| | | | | | | | | | | | | | | |
Collapse
|
39
|
Okada T, Ikeda K, Wakabayashi M, Ogawa M, Matsuzaki K. Formation of toxic Abeta(1-40) fibrils on GM1 ganglioside-containing membranes mimicking lipid rafts: polymorphisms in Abeta(1-40) fibrils. J Mol Biol 2008; 382:1066-74. [PMID: 18692507 DOI: 10.1016/j.jmb.2008.07.072] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2008] [Revised: 07/24/2008] [Accepted: 07/24/2008] [Indexed: 02/02/2023]
Abstract
The abnormal aggregation and deposition of amyloid beta protein (Abeta) on neuronal cells are critical to the onset of Alzheimer's disease. The entity (oligomers or fibrils) of toxic Abeta species responsible for the pathogenesis of the disease has been controversial. We have reported that the Abeta aggregates on ganglioside-rich domains of neuronal PC12 cells as well as in raft-like model membranes. Here, we identified toxic Abeta(1-40) aggregates formed with GM1-ganglioside-containing membranes. Abeta(1-40) was incubated with raft-like liposomes composed of GM1/cholesterol/sphingomyelin at 1:2:2 and 37 degrees C. After a lag period, toxic amyloid fibrils with a width of 12 nm were formed and subsequently laterally assembled with slight changes in their secondary structure as confirmed by viability assay, thioflavin-T fluorescence, circular dichroism, and transmission electron microscopy. In striking contrast, Abeta fibrils formed without membranes were thinner (6.7 nm) and much less toxic because of weaker binding to cell membranes and a smaller surface hydrophobicity. This study suggests that toxic Abeta(1-40) species formed on membranes are not soluble oligomers but amyloid fibrils and that Abeta(1-40) fibrils exhibit polymorphisms.
Collapse
Affiliation(s)
- Takuma Okada
- Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | | | | | | | | |
Collapse
|
40
|
Szczepanik AM, Rampe D, Ringheim GE. Amyloid-β peptide fragments p3 and p4 induce pro-inflammatory cytokine and chemokine production in vitro and in vivo. J Neurochem 2008. [DOI: 10.1046/j.1471-4159.2001.00240.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
41
|
Kent A, Jha AK, Fitzgerald JE, Freed KF. Benchmarking implicit solvent folding simulations of the amyloid beta(10-35) fragment. J Phys Chem B 2008; 112:6175-86. [PMID: 18348560 PMCID: PMC2719849 DOI: 10.1021/jp077099h] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A pathogenetic feature of Alzhemier disease is the aggregation of monomeric beta-amyloid proteins (Abeta) to form oligomers. Usually these oligomers of long peptides aggregate on time scales of microseconds or longer, making computational studies using atomistic molecular dynamics models prohibitively expensive and making it essential to develop computational models that are cheaper and at the same time faithful to physical features of the process. We benchmark the ability of our implicit solvent model to describe equilibrium and dynamic properties of monomeric Abeta(10-35) using all-atom Langevin dynamics (LD) simulations, since Alphabeta(10-35) is the only fragment whose monomeric properties have been measured. The accuracy of the implicit solvent model is tested by comparing its predictions with experiment and with those from a new explicit water MD simulation, (performed using CHARMM and the TIP3P water model) which is approximately 200 times slower than the implicit water simulations. The dependence on force field is investigated by running multiple trajectories for Alphabeta(10-35) using the CHARMM, OPLS-aal, and GS-AMBER94 force fields, whereas the convergence to equilibrium is tested for each force field by beginning separate trajectories from the native NMR structure, a completely stretched structure, and from unfolded initial structures. The NMR order parameter, S2, is computed for each trajectory and is compared with experimental data to assess the best choice for treating aggregates of Alphabeta. The computed order parameters vary significantly with force field. Explicit and implicit solvent simulations using the CHARMM force fields display excellent agreement with each other and once again support the accuracy of the implicit solvent model. Alphabeta(10-35) exhibits great flexibility, consistent with experiment data for the monomer in solution, while maintaining a general strand-loop-strand motif with a solvent-exposed hydrophobic patch that is believed to be important for aggregation. Finally, equilibration of the peptide structure requires an implicit solvent LD simulation as long as 30 ns.
Collapse
Affiliation(s)
- Andrew Kent
- Department of Chemistry, The University of Chicago, Chicago, IL 60637
- The James Franck Institute, The University of Chicago, Chicago, IL 60637
| | - Abhishek K Jha
- Department of Chemistry, The University of Chicago, Chicago, IL 60637
- Institute of Biophysical Dynamics, The University of Chicago, Chicago, IL 60637
- The James Franck Institute, The University of Chicago, Chicago, IL 60637
| | - James E Fitzgerald
- Institute of Biophysical Dynamics, The University of Chicago, Chicago, IL 60637
- Department of Mathematics, The University of Chicago, Chicago, IL 60637
- Department of Physics, The University of Chicago, Chicago, IL 60637
| | - Karl F Freed
- Department of Chemistry, The University of Chicago, Chicago, IL 60637
- The James Franck Institute, The University of Chicago, Chicago, IL 60637
| |
Collapse
|
42
|
Griffiths HH, Morten IJ, Hooper NM. Emerging and potential therapies for Alzheimer's disease. Expert Opin Ther Targets 2008; 12:693-704. [DOI: 10.1517/14728222.12.6.693] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
|
43
|
Triguero L, Singh R, Prabhakar R. Comparative molecular dynamics studies of wild-type and oxidized forms of full-length Alzheimer amyloid beta-peptides Abeta(1-40) and Abeta(1-42). J Phys Chem B 2008; 112:7123-31. [PMID: 18476733 DOI: 10.1021/jp801168v] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
In this study, all-atom 50 ns molecular dynamics simulations are performed on the full-length amyloid beta (Abeta) monomers (WT-Abeta(1-40) and WT-Abeta(1-42)) and their oxidized forms (Met35(O)-Abeta(1-40) and Met35(O)-Abeta(1-42)) in aqueous solution. The effects of the oxidation state of Met35 and the presence of dipeptide (Ile41-Ala42) on the secondary structures of the three distinct regions (the central hydrophobic core region 17-21 (LVFFA), the loop 23-28 (DVGSNK), and the second hydrophobic domain 29-35 (GAIIGLM)) of all monomers have been analyzed in detail, and results are compared with the available experimental information. Our simulations indicate that the WT-Abeta(1-40) monomer adopts an overall beta-hairpin-like structure, which is promoted by the turn region (24-27). This turn region is stabilized through salt-bridge formation between the Asp23 and Lys28 residues. In contrast, the overall structure of the oxidized (Met35(O)-Abeta(1-40)) monomer can be divided into three well-defined bend regions separated by coil segments. These structural differences may be critical for the measured decrease in the rate of aggregation of Met35(O)-Abeta(1-40) peptide. In the WT-Abeta(1-42) monomer, in comparison to the WT-Abeta(1-40), the Asp23-Lys28 salt bridge is absent, and consequently, the turn in the middle (24-27) region has a smaller curvature. The observed difference in the aggregation rates of these two peptides may be related to the opening of the turn (24-27) stabilized by the Asp23-Lys28 salt bridge. For WT-Abeta(1-42), in the absence of this salt bridge, the unfolding and aggregation events may be more favorable than for WT-Abeta(1-40).
Collapse
Affiliation(s)
- Luciano Triguero
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, FL 33146, USA
| | | | | |
Collapse
|
44
|
Gordon LM, Nisthal A, Lee AB, Eskandari S, Ruchala P, Jung CL, Waring AJ, Mobley PW. Structural and functional properties of peptides based on the N-terminus of HIV-1 gp41 and the C-terminus of the amyloid-beta protein. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2008; 1778:2127-37. [PMID: 18515070 DOI: 10.1016/j.bbamem.2008.05.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2007] [Revised: 04/07/2008] [Accepted: 05/06/2008] [Indexed: 11/30/2022]
Abstract
Given their high alanine and glycine levels, plaque formation, alpha-helix to beta-sheet interconversion and fusogenicity, FP (i.e., the N-terminal fusion peptide of HIV-1 gp41; 23 residues) and amyloids were proposed as belonging to the same protein superfamily. Here, we further test whether FP may exhibit 'amyloid-like' characteristics, by contrasting its structural and functional properties with those of Abeta(26-42), a 17-residue peptide from the C-terminus of the amyloid-beta protein responsible for Alzheimer's. FTIR spectroscopy, electron microscopy, light scattering and predicted amyloid structure aggregation (PASTA) indicated that aqueous FP and Abeta(26-42) formed similar networked beta-sheet fibrils, although the FP fibril interactions were weaker. FP and Abeta(26-42) both lysed and aggregated human erythrocytes, with the hemolysis-onsets correlated with the conversion of alpha-helix to beta-sheet for each peptide in liposomes. Congo red (CR), a marker of amyloid plaques in situ, similarly inhibited either FP- or Abeta(26-42)-induced hemolysis, and surface plasmon resonance indicated that this may be due to direct CR-peptide binding. These findings suggest that membrane-bound beta-sheets of FP may contribute to the cytopathicity of HIV in vivo through an amyloid-type mechanism, and support the classification of HIV-1 FP as an 'amyloid homolog' (or 'amylog').
Collapse
Affiliation(s)
- Larry M Gordon
- Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA
| | | | | | | | | | | | | | | |
Collapse
|
45
|
Zhang B, Dong Y, Zhang G, Moir RD, Xia W, Yue Y, Tian M, Culley DJ, Crosby G, Tanzi RE, Xie Z. The inhalation anesthetic desflurane induces caspase activation and increases amyloid beta-protein levels under hypoxic conditions. J Biol Chem 2008; 283:11866-75. [PMID: 18326038 PMCID: PMC2335348 DOI: 10.1074/jbc.m800199200] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2008] [Revised: 02/11/2008] [Indexed: 11/06/2022] Open
Abstract
Perioperative factors including hypoxia, hypocapnia, and certain anesthetics have been suggested to contribute to Alzheimer disease (AD) neuropathogenesis. Desflurane is one of the most commonly used inhalation anesthetics. However, the effects of desflurane on AD neuropathogenesis have not been previously determined. Here, we set out to assess the effects of desflurane and hypoxia on caspase activation, amyloid precursor protein (APP) processing, and amyloid beta-protein (Abeta) generation in H4 human neuroglioma cells (H4 naïve cells) as well as those overexpressing APP (H4-APP cells). Neither 12% desflurane nor hypoxia (18% O(2)) alone affected caspase-3 activation, APP processing, and Abeta generation. However, treatment with a combination of 12% desflurane and hypoxia (18% O(2)) (desflurane/hypoxia) for 6 h induced caspase-3 activation, altered APP processing, and increased Abeta generation in H4-APP cells. Desflurane/hypoxia also increased levels of beta-site APP-cleaving enzyme in H4-APP cells. In addition, desflurane/hypoxia-induced Abeta generation could be reduced by the broad caspase inhibitor benzyloxycarbonyl-VAD. Finally, the Abeta aggregation inhibitor clioquinol and gamma-secretase inhibitor L-685,458 attenuated caspase-3 activation induced by desflurane/hypoxia. In summary, desflurane can induce Abeta production and caspase activation, but only in the presence of hypoxia. Pending in vivo confirmation, these data may have profound implications for anesthesia care in elderly patients, and especially those with AD.
Collapse
Affiliation(s)
- Bin Zhang
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129-2060, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
46
|
Nagarajan S, Ramalingam K, Neelakanta Reddy P, Cereghetti DM, Padma Malar EJ, Rajadas J. Lipid-induced conformational transition of the amyloid core fragment Abeta(28-35) and its A30G and A30I mutants. FEBS J 2008; 275:2415-27. [PMID: 18422968 DOI: 10.1111/j.1742-4658.2008.06378.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The interaction of the beta-amyloid peptide (Abeta) with neuronal membranes could play a key role in the pathogenesis of Alzheimer's disease. Recent studies have focused on the interactions of Abeta oligomers to explain the neuronal toxicity accompanying Alzheimer's disease. In our study, we have investigated the role of lipid interactions with soluble Abeta(28-35) (wild-type) and its mutants A30G and A30I in their aggregation and conformational preferences. CD and Trp fluorescence spectroscopic studies indicated that, immediately on dissolution, these peptides adopted a random coil structure. Upon addition of negatively charged 1,2-dipalmitoyl-syn-glycero-3-phospho-rac-(glycerol) sodium salt (PG) lipid, the wild-type and A30I mutant underwent reorganization into a predominant beta-sheet structure. However, no conformational changes were observed in the A30G mutant on interaction with PG. In contrast, the presence of zwitterionic 1,2-dipalmitoyl-syn-glycero-3-phosphatidylcholine (PC) lipid had no effect on the conformation of these three peptides. These observations were also confirmed with atomic force microscopy and the thioflavin-T assay. In the presence of PG vesicles, both the wild-type and A30I mutant formed fibrillar structures within 2 days of incubation in NaCl/P(i), but not in their absence. Again, no oligomerization was observed with PC vesicles. The Trp studies also revealed that both ends of the three peptides are not buried deep in the vesicle membrane. Furthermore, fluorescence spectroscopy using the environment-sensitive probe 1,6-diphenyl-1,3,5-hexatriene showed an increase in the membrane fluidity upon exposure of the vesicles to the peptides. The latter effect may result from the lipid head group interactions with the peptides. Fluorescence resonance energy transfer experiments revealed that these peptides undergo a random coil-to-sheet conversion in solution on aging and that this process is accelerated by negatively charged lipid vesicles. These results indicate that aggregation depends on hydrophobicity and propensity to form beta-sheets of the amyloid peptide, and thus offer new insights into the mechanism of amyloid neurodegenerative disease.
Collapse
Affiliation(s)
- Sureshbabu Nagarajan
- Bio-Organic and Neurochemistry Laboratory, Central Leather Research Institute, Adyar, Chennai, India
| | | | | | | | | | | |
Collapse
|
47
|
Triguero L, Singh R, Prabhakar R. Molecular Dynamics Study To Investigate the Effect of Chemical Substitutions of Methionine 35 on the Secondary Structure of the Amyloid β (Aβ(1−42)) Monomer in Aqueous Solution. J Phys Chem B 2008; 112:2159-67. [DOI: 10.1021/jp0771872] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Luciano Triguero
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida 33146
| | - Rajiv Singh
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida 33146
| | - Rajeev Prabhakar
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida 33146
| |
Collapse
|
48
|
Florent-Béchard S, Malaplate-Armand C, Koziel V, Kriem B, Olivier JL, Pillot T, Oster T. Towards a nutritional approach for prevention of Alzheimer's disease: Biochemical and cellular aspects. J Neurol Sci 2007; 262:27-36. [PMID: 17681547 DOI: 10.1016/j.jns.2007.06.046] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Alzheimer's disease (AD) is a major public health concern in all countries. Although the precise cause of AD is still unknown, a growing body of evidence supports the notion that soluble amyloid beta-peptide (Abeta) may be the proximate cause of synaptic injuries and neuronal death early in the disease. AD patients display lower levels of docosahexaenoic acid (DHA, C22:6 ; n-3) in plasma and brain tissues as compared to age-matched controls. Furthermore, epidemiological studies suggest that high DHA intake might have protective properties against neurodegenerative diseases. These observations are supported by in vivo studies showing that DHA-rich diets limits the synaptic loss and cognitive defects induced by Abeta peptide. Although the molecular basis of these neuroprotective effects remains unknown, several mechanisms have been proposed such as (i) regulation of the expression of potentially protective genes, (ii) activation of anti-inflammatory pathways, (iii) modulation of functional properties of the synaptic membranes along with changes in their physicochemical and structural features.
Collapse
Affiliation(s)
- Sabrina Florent-Béchard
- Lipidomix (JE 2482), ENSAIA-INPL, University of Nancy, 15, rue du Bois de la Champelle 54505, Vandoeuvre-lès-Nancy, France
| | | | | | | | | | | | | |
Collapse
|
49
|
Okada T, Wakabayashi M, Ikeda K, Matsuzaki K. Formation of Toxic Fibrils of Alzheimer’s Amyloid β-Protein-(1–40) by Monosialoganglioside GM1, a Neuronal Membrane Component. J Mol Biol 2007; 371:481-9. [PMID: 17582434 DOI: 10.1016/j.jmb.2007.05.069] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2007] [Revised: 05/08/2007] [Accepted: 05/21/2007] [Indexed: 10/23/2022]
Abstract
A pathological hallmark of Alzheimer's disease (AD) is the deposition of amyloid beta-protein (Abeta) in fibrillar form on neuronal cells. However, the role of Abeta fibrils in neuronal dysfunction is highly controversial. This study demonstrates that monosialoganglioside GM1 (GM1) released from damaged neurons catalyzes the formation of Abeta fibrils, the toxicity and the cell affinity of which are much stronger than those of Abeta fibrils formed in phosphate-buffered saline. Abeta-(1-40) was incubated with equimolar GM1 at 37 degrees C. After a lag period of 6-12 h, amyloid fibrils were formed, as confirmed by circular dichroism, thioflavin-T fluorescence, size-exclusion chromatography, and transmission electron microscopy. The fibrils showed significant cytotoxicity against PC12 cells differentiated with nerve growth factor. Trisialoganglioside GT1b also facilitated the fibrillization, although the effect was weaker than that of GM1. Our study suggests an exacerbation mechanism of AD and an importance of polymorphisms in Abeta fibrils during the pathogenesis of the disease.
Collapse
Affiliation(s)
- Takuma Okada
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | | | | | | |
Collapse
|
50
|
Youssef I, Florent-Béchard S, Malaplate-Armand C, Koziel V, Bihain B, Olivier JL, Leininger-Muller B, Kriem B, Oster T, Pillot T. N-truncated amyloid-beta oligomers induce learning impairment and neuronal apoptosis. Neurobiol Aging 2007; 29:1319-33. [PMID: 17459527 DOI: 10.1016/j.neurobiolaging.2007.03.005] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2006] [Revised: 02/23/2007] [Accepted: 03/04/2007] [Indexed: 01/09/2023]
Abstract
N-terminal-truncated forms of amyloid-beta (A beta) peptide have been recently suggested to play a pivotal role early in Alzheimer's disease (AD). Among them, A beta 3(pE)-42 peptide, starting with pyroglutamyl at residue Glu-3, is considered as the predominant A beta species in AD plaques and pre-amyloid lesions. Its abundance is reported to be directly proportional to the severity of the clinical phenotype. The present study investigates the effects of soluble oligomeric A beta 3(pE)-42 after intracerebroventricular injection on mice learning ability and the molecular mechanisms of its in vitro neurotoxicity. Mice injected with soluble A beta 3(pE)-42 or A beta(l-42) displayed impaired spatial working memory and delayed memory acquisition in Y-maze and Morris water maze tests, while those injected with soluble A beta(42-1) showed no effect. These cognitive alterations were associated with free radical overproduction in the hippocampus and olfactory bulbs, but not in the cerebral cortex or cerebellum. In vitro, A beta 3(pE)-42 oligomers induced a redox-sensitive neuronal apoptosis involving caspase activation and an arachidonic acid-dependent pro-inflammatory pathway. These data suggest that A beta 3(pE)-42 could mediate the neurodegenerative process and subsequent cognitive alteration occurring in preclinical AD stages.
Collapse
Affiliation(s)
- Ihsen Youssef
- Lipidomix, JE 2482, INPL, Laboratoire de Médecine et Thérapeutique Moléculaire, 15 rue du Bois de la Champelle, 54505 Vandoeuvre-lès-Nancy, France
| | | | | | | | | | | | | | | | | | | |
Collapse
|