1
|
Karapetyan G, Fereshetyan K, Harutyunyan H, Yenkoyan K. The synergy of β amyloid 1-42 and oxidative stress in the development of Alzheimer's disease-like neurodegeneration of hippocampal cells. Sci Rep 2022; 12:17883. [PMID: 36284177 PMCID: PMC9596457 DOI: 10.1038/s41598-022-22761-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 10/19/2022] [Indexed: 01/20/2023] Open
Abstract
Alzheimer's disease (AD) is a type of dementia that affects memory, thinking and behavior. Symptoms eventually become severe enough to interfere with daily tasks. Understanding the etiology and pathogenesis of AD is necessary for the development of strategies for AD prevention and/or treatment, and modeling of this pathology is an important step in achieving this goal. β-amyloid peptide (Aβ) injection is a widely used approach for modeling AD. Nevertheless, it has been reported that the model constructed by injection of Aβ in combination with a prooxidant cocktail (ferrous sulfate, Aβ, and buthionine sulfoximine (BSO) (FAB)) best reflects the natural development of this disease. The relationship between oxidative stress and Aβ deposition and their respective roles in Aβ-induced pathology in different animal models of AD have been thoroughly investigated. In the current paper, we compared the effects of Aβ 1-42 alone with that of Aβ-associated oxidative stress induced by the FAB cocktail on the neurodegeneration of hippocampal cells in vitro. We constructed a FAB-induced AD model using rat primary hippocampal cells and analyzed the contribution of each compound. The study mainly focused on the prooxidant aspects of AD pathogenesis. Moreover, cellular bioenergetics was assessed and routine metabolic tests were performed to determine the usefulness of this model. The data clearly show that aggregated Aβ1-42 alone is significantly less toxic to hippocampal cells. Aggregated Aβ damages neurons, and glial cells proliferate to remove Aβ from the hippocampus. External prooxidant agents (Fe2+) or inhibition of internal antioxidant defense by BSO has more toxic effects on hippocampal cells than aggregated Aβ alone. Moreover, hippocampal cells fight against Aβ-induced damage more effectively than against oxidative damage. However, the combination of Aβ with external oxidative damage and inhibition of internal antioxidant defense is even more toxic, impairs cellular defense systems, and may mimic the late phase of AD-associated cell damage. Our findings strongly indicate a critical role for the combination of Aβ and oxidative stress in the development of neurodegeneration in vitro.
Collapse
Affiliation(s)
- Gohar Karapetyan
- grid.427559.80000 0004 0418 5743Neuroscience Laboratory, Cobrain Center, Yerevan State Medical University named after M. Heratsi, 2 Koryun Str., 0025 Yerevan, Armenia
| | - Katarine Fereshetyan
- grid.427559.80000 0004 0418 5743Neuroscience Laboratory, Cobrain Center, Yerevan State Medical University named after M. Heratsi, 2 Koryun Str., 0025 Yerevan, Armenia ,grid.427559.80000 0004 0418 5743Department of Biochemistry, Yerevan State Medical University named after M. Heratsi, Yerevan, Armenia
| | - Hayk Harutyunyan
- grid.427559.80000 0004 0418 5743Neuroscience Laboratory, Cobrain Center, Yerevan State Medical University named after M. Heratsi, 2 Koryun Str., 0025 Yerevan, Armenia
| | - Konstantin Yenkoyan
- grid.427559.80000 0004 0418 5743Neuroscience Laboratory, Cobrain Center, Yerevan State Medical University named after M. Heratsi, 2 Koryun Str., 0025 Yerevan, Armenia ,grid.427559.80000 0004 0418 5743Department of Biochemistry, Yerevan State Medical University named after M. Heratsi, Yerevan, Armenia
| |
Collapse
|
2
|
Munusamy S, Conde R, Bertrand B, Munoz-Garay C. Biophysical approaches for exploring lipopeptide-lipid interactions. Biochimie 2020; 170:173-202. [PMID: 31978418 PMCID: PMC7116911 DOI: 10.1016/j.biochi.2020.01.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 01/19/2020] [Indexed: 02/07/2023]
Abstract
In recent years, lipopeptides (LPs) have attracted a lot of attention in the pharmaceutical industry due to their broad-spectrum of antimicrobial activity against a variety of pathogens and their unique mode of action. This class of compounds has enormous potential for application as an alternative to conventional antibiotics and for pest control. Understanding how LPs work from a structural and biophysical standpoint through investigating their interaction with cell membranes is crucial for the rational design of these biomolecules. Various analytical techniques have been developed for studying intramolecular interactions with high resolution. However, these tools have been barely exploited in lipopeptide-lipid interactions studies. These biophysical approaches would give precise insight on these interactions. Here, we reviewed these state-of-the-art analytical techniques. Knowledge at this level is indispensable for understanding LPs activity and particularly their potential specificity, which is relevant information for safe application. Additionally, the principle of each analytical technique is presented and the information acquired is discussed. The key challenges, such as the selection of the membrane model are also been briefly reviewed. A brief overview of topics to understand the generalities of lipopeptide (LP) science. Main analytical techniques used to reveal the interaction and the distorting effect of LP on artificial membranes. Guidelines for selecting of the most adequate membrane models for the given analytical technique.
Collapse
Affiliation(s)
- Sathishkumar Munusamy
- Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, 62210, Cuernavaca, Mexico
| | - Renaud Conde
- Centro de Investigación Sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, Mexico
| | - Brandt Bertrand
- Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, 62210, Cuernavaca, Mexico
| | - Carlos Munoz-Garay
- Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, 62210, Cuernavaca, Mexico.
| |
Collapse
|
3
|
Roberts BR, Lind M, Wagen AZ, Rembach A, Frugier T, Li QX, Ryan TM, McLean CA, Doecke JD, Rowe CC, Villemagne VL, Masters CL. Biochemically-defined pools of amyloid-β in sporadic Alzheimer's disease: correlation with amyloid PET. Brain 2017; 140:1486-1498. [PMID: 28383676 DOI: 10.1093/brain/awx057] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 01/20/2017] [Indexed: 02/06/2023] Open
Abstract
We fractionated frontal cortical grey matter from human Alzheimer's disease and control subjects into four biochemically defined pools that represent four distinct compartments: soluble/cytosolic, peripheral membrane/vesicular cargo, integral lipid/membranous pools and aggregated/insoluble debris. Most of the readily extractable amyloid-β remains associated with a lipid/membranous compartment. There is an exchange of amyloid-β between the biochemical pools that was lost for the amyloid-β42 species in Alzheimer's disease, consistent with the peptide being irreversibly trapped in extracellular deposits. The quantitative amyloid-β data, combined with magnetic resonance imaging volumetric analysis of the amount of cortical grey matter in brain, allowed us to estimate the total mass of amyloid-β in Alzheimer's disease (6.5 mg) and control (1.7 mg) brains. The threshold positron emission tomography standard uptake value ratio of 1.4 equates to 5.0 μg amyloid-β/g of grey matter and the mean Alzheimer's disease dementia standard uptake value ratio level of 2.3 equates to 11.20 μg amyloid-β/g of grey matter. It takes 19 years to accumulate amyloid from the threshold positron emission tomography standard uptake value ratio to the mean value observed for Alzheimer's disease dementia. This accumulation time window combined with the difference of 4.8 mg of amyloid-β between Alzheimer's disease and control brain allows for a first approximation of amyloid-β accumulation of 28 ng/h. This equates to an estimated 2-5% of the total amyloid-β production being deposited as insoluble plaques. Understanding these rates of amyloid-β accumulation allows for a more quantitative approach in targeting the failure of amyloid-β clearance in sporadic Alzheimer's disease.
Collapse
Affiliation(s)
- Blaine R Roberts
- The Florey Institute, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Monica Lind
- The Florey Institute, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Aaron Z Wagen
- The Florey Institute, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Alan Rembach
- The Florey Institute, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Tony Frugier
- Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Qiao-Xin Li
- The Florey Institute, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Timothy M Ryan
- The Florey Institute, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Catriona A McLean
- The Florey Institute, The University of Melbourne, Parkville, Victoria 3010, Australia.,Department of Anatomical Pathology, Alfred Hospital, Prahran, Victoria 3004, Australia
| | - James D Doecke
- CSIRO Health and Biosecurity/Australian e-Health Research Centre and Cooperative Research Centre of Mental Health, Brisbane, QLD, Australia
| | - Christopher C Rowe
- The Florey Institute, The University of Melbourne, Parkville, Victoria 3010, Australia.,Department of Nuclear Medicine and Centre for PET, Austin Health, Heidelberg, Victoria, Australia
| | - Victor L Villemagne
- The Florey Institute, The University of Melbourne, Parkville, Victoria 3010, Australia.,Department of Nuclear Medicine and Centre for PET, Austin Health, Heidelberg, Victoria, Australia
| | - Colin L Masters
- The Florey Institute, The University of Melbourne, Parkville, Victoria 3010, Australia
| |
Collapse
|
4
|
Hossain S, Hashimoto M, Katakura M, Al Mamun A, Shido O. Medicinal value of asiaticoside for Alzheimer's disease as assessed using single-molecule-detection fluorescence correlation spectroscopy, laser-scanning microscopy, transmission electron microscopy, and in silico docking. Altern Ther Health Med 2015; 15:118. [PMID: 25880304 PMCID: PMC4422550 DOI: 10.1186/s12906-015-0620-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Accepted: 03/16/2015] [Indexed: 01/09/2023]
Abstract
BACKGROUND Identifying agents that inhibit amyloid beta peptide (Aβ) aggregation is the ultimate goal for slowing Alzheimer's disease (AD) progression. This study investigated whether the glycoside asiaticoside inhibits Aβ1-42 fibrillation in vitro. METHODS Fluorescence correlation spectroscopy (FCS), evaluating the Brownian diffusion times of moving particles in a small confocal volume at the single-molecule level, was used. If asiaticoside inhibits early Aβ1-42 fibrillation steps, more Aβs would remain free and rapidly diffuse in the confocal volume. In contrast, "weaker or no inhibition" permits a greater number of Aβs to polymerize into oligomers, leading to fibers and gives rise to slow diffusion times in the solution. Trace amounts of 5-carboxytetramethylrhodamine (TAMRA)-labeled Aβ1-42 in the presence of excess unlabeled Aβ1-42 (10 μM) was used as a fluorescent probe. Steady-state and kinetic-Thioflavin T (ThT) fluorospectroscopy, laser-scanning fluorescence microscopy (LSM), and transmission electron microscopy (TEM) were also used to monitor fibrillation. Binding of asiaticoside with Aβ1-42 at the atomic level was computationally examined using the Molegro Virtual Docker and PatchDock. RESULTS With 1 h of incubation time for aggregation, FCS data analysis revealed that the diffusion time of TAMRA-Aβ1-42 was 208 ± 4 μs, which decreased to 164 ± 8.0 μs in the presence of asiaticoside, clearly indicating that asiaticoside inhibited the early stages Aβ1-42 of fibrillation, leaving more free Aβs in the solution and permitting their rapid diffusion in the confocal volume. The inhibitory effects were also evidenced by reduced fiber formation as assessed by steady-state and kinetic ThT fluorospectroscopy, LSM, and TEM. Asiaticoside elongated the lag phase of Aβ1-42 fibrillation, indicating the formation of smaller amyloid species were impaired in the presence of asiaticoside. Molecular docking revealed that asiaticoside binds with amyloid intra- and inter-molecular amino acid residues, which are responsible for β-sheet formation and longitudinal extension of fibrils. CONCLUSION Finally, asiaticoside prevents amyloidogenesis that precedes neurodegeneration in patients with Alzheimer's disease.
Collapse
|
5
|
Theillet FX, Binolfi A, Frembgen-Kesner T, Hingorani K, Sarkar M, Kyne C, Li C, Crowley PB, Gierasch L, Pielak GJ, Elcock AH, Gershenson A, Selenko P. Physicochemical properties of cells and their effects on intrinsically disordered proteins (IDPs). Chem Rev 2014; 114:6661-714. [PMID: 24901537 PMCID: PMC4095937 DOI: 10.1021/cr400695p] [Citation(s) in RCA: 338] [Impact Index Per Article: 33.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Indexed: 02/07/2023]
Affiliation(s)
- Francois-Xavier Theillet
- Department
of NMR-supported Structural Biology, In-cell NMR Laboratory, Leibniz Institute of Molecular Pharmacology (FMP Berlin), Robert-Roessle Strasse 10, 13125 Berlin, Germany
| | - Andres Binolfi
- Department
of NMR-supported Structural Biology, In-cell NMR Laboratory, Leibniz Institute of Molecular Pharmacology (FMP Berlin), Robert-Roessle Strasse 10, 13125 Berlin, Germany
| | - Tamara Frembgen-Kesner
- Department
of Biochemistry, University of Iowa, Bowen Science Building, 51 Newton
Road, Iowa City, Iowa 52242, United States
| | - Karan Hingorani
- Departments
of Biochemistry & Molecular Biology and Chemistry, Program in
Molecular & Cellular Biology, University
of Massachusetts, Amherst, 240 Thatcher Way, Amherst, Massachusetts 01003, United States
| | - Mohona Sarkar
- Department
of Chemistry, Department of Biochemistry and Biophysics and Lineberger
Comprehensive Cancer Center, University
of North Carolina, Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| | - Ciara Kyne
- School
of Chemistry, National University of Ireland,
Galway, University Road, Galway, Ireland
| | - Conggang Li
- Key Laboratory
of Magnetic Resonance in Biological Systems, State Key Laboratory
of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Center
for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, P.R. China
| | - Peter B. Crowley
- School
of Chemistry, National University of Ireland,
Galway, University Road, Galway, Ireland
| | - Lila Gierasch
- Departments
of Biochemistry & Molecular Biology and Chemistry, Program in
Molecular & Cellular Biology, University
of Massachusetts, Amherst, 240 Thatcher Way, Amherst, Massachusetts 01003, United States
| | - Gary J. Pielak
- Department
of Chemistry, Department of Biochemistry and Biophysics and Lineberger
Comprehensive Cancer Center, University
of North Carolina, Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| | - Adrian H. Elcock
- Department
of Biochemistry, University of Iowa, Bowen Science Building, 51 Newton
Road, Iowa City, Iowa 52242, United States
| | - Anne Gershenson
- Departments
of Biochemistry & Molecular Biology and Chemistry, Program in
Molecular & Cellular Biology, University
of Massachusetts, Amherst, 240 Thatcher Way, Amherst, Massachusetts 01003, United States
| | - Philipp Selenko
- Department
of NMR-supported Structural Biology, In-cell NMR Laboratory, Leibniz Institute of Molecular Pharmacology (FMP Berlin), Robert-Roessle Strasse 10, 13125 Berlin, Germany
| |
Collapse
|
6
|
Mittag JJ, Milani S, Walsh DM, Rädler JO, McManus JJ. Simultaneous measurement of a range of particle sizes during Aβ1-42 fibrillogenesis quantified using fluorescence correlation spectroscopy. Biochem Biophys Res Commun 2014; 448:195-9. [PMID: 24769478 DOI: 10.1016/j.bbrc.2014.04.088] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Accepted: 04/17/2014] [Indexed: 01/15/2023]
Abstract
Low molecular weight oligomers of amyloid beta (Aβ) are important drivers of Alzheimer's disease. A decrease in Aβ monomer levels in human cerebrospinal fluid (CSF) is observed in Alzheimers' patients and is a robust biomarker of the disease. It has been suggested that the decrease in monomer levels in CSF is due to the formation of Aβ oligomers. A robust technique capable of identifying Aβ oligomers in CSF is therefore desirable. We have used fluorescence correlation spectroscopy and a five Gaussian distribution model (5GDM) to monitor the aggregation of Aβ1-42 in sodium phosphate buffer and in artificial cerebrospinal fluid (ACSF). In buffer, several different sized components (monomer, oligomers, protofibrils and fibrils) can be identified simultaneously using 5GDM. In ACSF, the faster kinetics of fibrillogenesis leads to the formation of fibrils on very short timescales. This analysis method can also be used to monitor the aggregation of other proteins, nanoparticles or colloids, even in complex biological fluids.
Collapse
Affiliation(s)
- Judith J Mittag
- Ludwig-Maximilians-Universität, Fakultät für Physik & CeNS, Geschwister-Scholl-Platz 1, 80539 München, Germany.
| | - Silvia Milani
- Ludwig-Maximilians-Universität, Fakultät für Physik & CeNS, Geschwister-Scholl-Platz 1, 80539 München, Germany.
| | - Dominic M Walsh
- Laboratory for Neurodegenerative Research, Center for Neurologic Diseases, Brigham & Women's Hospital, Harvard Institutes of Medicine, Boston, MA 02115, USA.
| | - Joachim O Rädler
- Ludwig-Maximilians-Universität, Fakultät für Physik & CeNS, Geschwister-Scholl-Platz 1, 80539 München, Germany.
| | - Jennifer J McManus
- Department of Chemistry, National University of Ireland Maynooth, Maynooth, Co. Kildare, Ireland.
| |
Collapse
|
7
|
Ciccotosto GD, Kozer N, Chow TTY, Chon JWM, Clayton AHA. Aggregation distributions on cells determined by photobleaching image correlation spectroscopy. Biophys J 2013; 104:1056-64. [PMID: 23473488 DOI: 10.1016/j.bpj.2013.01.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Revised: 12/17/2012] [Accepted: 01/02/2013] [Indexed: 11/29/2022] Open
Abstract
The organization of molecules into macromolecular (nanometer scale), supramolecular complexes (submicron-to-micron scale), and within subcellular domains, is an important architectural principle of cellular biology and biochemistry. Determining the precise nature and distribution of complexes within the cellular milieu is a challenging biophysical problem. Time-series analysis of laser scanning confocal microscopy images by image correlation spectroscopy (ICS) or fluctuation moments methods provides information on aggregation, flow, and dynamics of fluorescently tagged macromolecules. All the methods to date require a brightness standard to relate the experimental data to absolute aggregation. In this article, we show that ICS as a function of gradual photobleaching is a sensitive indicator of aggregation distribution on the submicron scale. Specifically, in photobleaching ICS, the extent of nonlinearity of the apparent cluster density as a function of bleaching is related to the size of clusters. The analysis is tested using computer simulations on model aggregate systems and then applied to an experimental determination of Aβ peptide aggregation on nerve cells. The analysis reveals time-dependent increases in Aβ1-42 peptide aggregation. Globally, the datasets could be described by a monomer-dimer-tetramer-hexamer or a monomer-dimer-trimer-pentamer model. The results demonstrate the utility of photobleaching with ICS for determining aggregation states on the supramolecular scale in intact cells without the requirement for a brightness standard.
Collapse
Affiliation(s)
- Giuseppe D Ciccotosto
- Department of Pathology and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Australia
| | | | | | | | | |
Collapse
|
8
|
Cernescu M, Stark T, Kalden E, Kurz C, Leuner K, Deller T, Göbel M, Eckert GP, Brutschy B. Laser-Induced Liquid Bead Ion Desorption Mass Spectrometry: An Approach to Precisely Monitor the Oligomerization of the β-Amyloid Peptide. Anal Chem 2012; 84:5276-84. [DOI: 10.1021/ac300258m] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Mihaela Cernescu
- Institute for Physical and Theoretical
Chemistry, Goethe-University, Frankfurt/M,
Germany, 60438
| | - Tina Stark
- Institute
for Organic Chemistry
and Chemical Biology, Goethe-University, Frankfurt/M, Germany, 60438
| | - Elisabeth Kalden
- Institute
for Organic Chemistry
and Chemical Biology, Goethe-University, Frankfurt/M, Germany, 60438
| | - Christopher Kurz
- Department of Pharmacology, Biocentre, Goethe-University, Frankfurt/M, Germany, 60438
| | - Kristina Leuner
- Department of Pharmacology, Biocentre, Goethe-University, Frankfurt/M, Germany, 60438
| | - Thomas Deller
- Institute of Clinical Neuroanatomy,
Dr. Senckenberg Anatomy, Goethe-University, Neuroscience Center, Frankfurt/M, Germany, 60590
| | - Michael Göbel
- Institute
for Organic Chemistry
and Chemical Biology, Goethe-University, Frankfurt/M, Germany, 60438
| | - Gunter P. Eckert
- Department of Pharmacology, Biocentre, Goethe-University, Frankfurt/M, Germany, 60438
| | - Bernhard Brutschy
- Institute for Physical and Theoretical
Chemistry, Goethe-University, Frankfurt/M,
Germany, 60438
| |
Collapse
|
9
|
Shah SB, Nolan R, Davis E, Stokin GB, Niesman I, Canto I, Glabe C, Goldstein LSB. Examination of potential mechanisms of amyloid-induced defects in neuronal transport. Neurobiol Dis 2009; 36:11-25. [PMID: 19497367 DOI: 10.1016/j.nbd.2009.05.016] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2009] [Revised: 05/03/2009] [Accepted: 05/25/2009] [Indexed: 01/31/2023] Open
Abstract
Microtubule-based neuronal transport pathways are impaired during the progression of Alzheimer's disease and other neurodegenerative conditions. However, mechanisms leading to defects in transport remain to be determined. We quantified morphological changes in neuronal cells following treatment with fibrils and unaggregated peptides of beta-amyloid (Abeta). Abeta fibrils induce axonal and dendritic swellings indicative of impaired transport. In contrast, Abeta peptides induce a necrotic phenotype in both neurons and non-neuronal cells. We tested several popular hypotheses by which aggregated Abeta could disrupt transport. Using fluorescent polystyrene beads, we developed experimental models of physical blockage and localized release of reactive oxygen species (ROS) that reliably induce swellings. Like the beads, Abeta fibrils localize in close proximity to swellings; however, fibril internalization is not required for disrupting transport. ROS and membrane permeability are also unlikely to be responsible for fibril-mediated toxicity. Collectively, our results indicate that multiple initiating factors converge upon pathways of defective transport.
Collapse
Affiliation(s)
- Sameer B Shah
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, USA
| | | | | | | | | | | | | | | |
Collapse
|
10
|
Sahoo B, Balaji J, Nag S, Kaushalya SK, Maiti S. Protein aggregation probed by two-photon fluorescence correlation spectroscopy of native tryptophan. J Chem Phys 2009; 129:075103. [PMID: 19044804 DOI: 10.1063/1.2969110] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Fluorescence correlation spectroscopy (FCS) has proven to be a powerful tool for the study of a range of biophysical problems including protein aggregation. However, the requirement of fluorescent labeling has been a major drawback of this approach. Here we show that the intrinsic tryptophan fluorescence, excited via a two-photon mechanism, can be effectively used to study the aggregation of tryptophan containing proteins by FCS. This method can also yield the tryptophan fluorescence lifetime in parallel, which provides a complementary parameter to understand the aggregation process. We demonstrate that the formation of soluble aggregates of barstar at pH 3.5 shows clear signatures both in the two-photon tryptophan FCS data and in the tryptophan lifetime analysis. The ability to probe the soluble aggregates of unmodified proteins is significant, given the major role played by this species in amyloid toxicity.
Collapse
Affiliation(s)
- Bankanidhi Sahoo
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005, India
| | | | | | | | | |
Collapse
|
11
|
Bakota L, Brandt R. Chapter 2 Live‐Cell Imaging in the Study of Neurodegeneration. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2009; 276:49-103. [DOI: 10.1016/s1937-6448(09)76002-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
|
12
|
Liu P, Ahmed S, Wohland T. The F-techniques: advances in receptor protein studies. Trends Endocrinol Metab 2008; 19:181-90. [PMID: 18387308 DOI: 10.1016/j.tem.2008.02.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2007] [Revised: 02/13/2008] [Accepted: 02/22/2008] [Indexed: 11/20/2022]
Abstract
Recent developments in advanced microscopy techniques, the so-called F-techniques, including Förster resonance energy transfer, fluorescence correlation spectroscopy and fluorescence lifetime imaging, have led to a wide range of novel applications in biology. The F-techniques provide quantitative information on biomolecules and their interactions and give high spatial and temporal resolution. In particular, their application to receptor protein studies has led to new insights into receptor localization, oligomerization, activation and function in vivo. This review focuses on the application of the F-techniques to the study of receptor molecules and mechanisms in the last three years and provides information on new modalities that will further improve their applicability and widen the range of biological questions that can be addressed.
Collapse
Affiliation(s)
- Ping Liu
- Department of Chemistry, National University of Singapore, Singapore
| | | | | |
Collapse
|
13
|
Dose-dependent and sequence-sensitive effects of amyloid-β peptide on neurosteroidogenesis in human neuroblastoma cells. Neurochem Int 2008; 52:948-55. [DOI: 10.1016/j.neuint.2008.01.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2007] [Revised: 12/20/2007] [Accepted: 01/17/2008] [Indexed: 11/15/2022]
|