1
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Ruiz M, Devkota R, Bergh PO, Nik AM, Blid Sköldheden S, Mondejar-Duran J, Tufvesson-Alm M, Bohlooly-Y M, Sanchez D, Carlsson P, Henricsson M, Jerlhag E, Borén J, Pilon M. Aging AdipoR2-deficient mice are hyperactive with enlarged brains excessively rich in saturated fatty acids. FASEB J 2024; 38:e23815. [PMID: 38989587 DOI: 10.1096/fj.202400293rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 06/04/2024] [Accepted: 06/28/2024] [Indexed: 07/12/2024]
Abstract
To investigate how the fatty acid composition of brain phospholipids influences brain-specific processes, we leveraged the AdipoR2 (adiponectin receptor 2) knockout mouse model in which the brain is enlarged, and cellular membranes are excessively rich in saturated fatty acids. Lipidomics analysis of brains at 2, 7, and 18 months of age showed that phosphatidylcholines, which make up about two-thirds of all cerebrum membrane lipids, contain a gross excess of saturated fatty acids in AdipoR2 knockout mice, and that this is mostly attributed to an excess palmitic acid (C16:0) at the expense of oleic acid (C18:1), consistent with a defect in fatty acid desaturation and elongation in the mutant. Specifically, there was a ~12% increase in the overall saturated fatty acid content within phosphatidylcholines and a ~30% increase in phosphatidylcholines containing two palmitic acids. Phosphatidylethanolamines, sphingomyelins, ceramides, lactosylceramides, and dihydroceramides also showed an excess of saturated fatty acids in the AdipoR2 knockout mice while nervonic acid (C24:1) was enriched at the expense of shorter saturated fatty acids in glyceroceramides. Similar defects were found in the cerebellum and myelin sheaths. Histology showed that cell density is lower in the cerebrum of AdipoR2 knockout mice, but electron microscopy did not detect reproducible defects in the ultrastructure of cerebrum neurons, though proteomics analysis showed an enrichment of electron transport chain proteins in the cerebellum. Behavioral tests showed that older (33 weeks old) AdipoR2 knockout mice are hyperactive and anxious compared to control mice of a similar age. Also, in contrast to control mice, the AdipoR2 knockout mice do not gain weight in old age but do have normal lifespans. We conclude that an excess fatty acid saturation in brain phospholipids is accompanied by hyperactivity but seems otherwise well tolerated.
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Affiliation(s)
- Mario Ruiz
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Ranjan Devkota
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Per-Olof Bergh
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Ali Moussavi Nik
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Sebastian Blid Sköldheden
- Department of Pharmacology, Institute of Neuroscience and physiology, University of Gothenburg, Gothenburg, Sweden
| | - Jorge Mondejar-Duran
- Instituto de Biomedicina y Genética Molecular, Excellence Unit, University of Valladolid-CSIC, Valladolid, Spain
| | - Maximilian Tufvesson-Alm
- Department of Pharmacology, Institute of Neuroscience and physiology, University of Gothenburg, Gothenburg, Sweden
| | | | - Diego Sanchez
- Instituto de Biomedicina y Genética Molecular, Excellence Unit, University of Valladolid-CSIC, Valladolid, Spain
| | - Peter Carlsson
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Marcus Henricsson
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Elisabet Jerlhag
- Department of Pharmacology, Institute of Neuroscience and physiology, University of Gothenburg, Gothenburg, Sweden
| | - Jan Borén
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Marc Pilon
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
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2
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Iizuka Y, Katano-Toki A, Hayashi F, Fujioka J, Takahashi H, Nakamura K. Exogenous polyserine fibrils change membrane properties of phosphatidylcholine-liposome and red blood cells. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2024; 1866:184331. [PMID: 38718958 DOI: 10.1016/j.bbamem.2024.184331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 03/29/2024] [Accepted: 04/29/2024] [Indexed: 05/12/2024]
Abstract
The causative genes for neurodegenerative polyglutamine (polyQ) diseases produce homopolymeric polyglutamine (polyQ), polyserine (polyS), polyalanine (polyA), polycysteine (polyC), and polyleucine (polyL) sequences by repeat-associated non-AUG (RAN) translation. The cytotoxicity of the intracellular polyQ and RAN products has been extensively investigated. However, little is known about the toxicity of the extracellular polyQ and RAN products on the membranes of viable cells. Because polyQ aggregates induce a deflated morphology of a model membrane, we hypothesized that extracellular polyQ and RAN products might affect the membrane properties of viable cells. In this study, we demonstrated that exogenous polyS fibrils but not polyS or polyQ non-fibril aggregates altered the thermal phase transition behavior of a model membrane composed of a phosphatidylcholine bilayer using differential scanning calorimetry. PolyS fibrils induced morphological changes in viable red blood cells (RBCs). However, both polyS and polyQ non-fibril aggregates had no effects on RBCs. These results highlight the possibility that extracellular fibrils generated from RAN products may alter the properties of neuronal cell membranes, which may contribute to changes in the brain pathology.
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Affiliation(s)
- Yutaro Iizuka
- Department of Laboratory Sciences, Gunma University Graduate School of Health Sciences, 3-39-22, Showa-machi, Maebashi, Gunma 371-8511, Japan
| | - Akiko Katano-Toki
- Department of Laboratory Sciences, Gunma University Graduate School of Health Sciences, 3-39-22, Showa-machi, Maebashi, Gunma 371-8511, Japan
| | - Fumio Hayashi
- Center for Instrumental Analysis, Organization for Promotion of Research and University Industry Collaboration, Gunma University, 1-5-1, Tenjin-cho, Kiryu, Gunma, 376-8515, Japan
| | - Jun Fujioka
- Department of Chemistry, Faculty of Science Division I, Tokyo University of Science, 1-3, Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan
| | - Hiroshi Takahashi
- Biophysics Laboratory, Division of Pure and Applied Science, Graduate School of Science and Technology, Gunma University, 4-2, Aramaki, Maebashi, Gunma 371-8510, Japan.
| | - Kazuhiro Nakamura
- Department of Laboratory Sciences, Gunma University Graduate School of Health Sciences, 3-39-22, Showa-machi, Maebashi, Gunma 371-8511, Japan.
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3
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Mangiarotti A, Dimova R. The spectral phasor approach to resolving membrane order with environmentally sensitive dyes. Methods Enzymol 2024; 700:105-126. [PMID: 38971597 DOI: 10.1016/bs.mie.2024.01.024] [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] [Indexed: 07/08/2024]
Abstract
Hyperspectral imaging is a technique that captures a three-dimensional array of spectral information at each spatial location within a sample, enabling precise characterization and discrimination of biological structures, materials, and chemicals, based on their unique spectral features. Nowadays most commercially available confocal microscopes allow hyperspectral imaging measurements, providing a valuable source of spatially resolved spectroscopic data. Spectral phasor analysis quantitatively and graphically transforms the fluorescence spectra at each pixel of a hyperspectral image into points in a polar plot, offering a visual representation of the spectral characteristics of fluorophores within the sample. Combining the use of environmentally sensitive dyes with phasor analysis of hyperspectral images provides a powerful tool for measuring small changes in lateral membrane heterogeneity. Here, we focus on applications of spectral phasor analysis for the probe LAURDAN on model membranes to resolve packing and hydration. The method is broadly applicable to other dyes and to complex systems such as cell membranes.
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Affiliation(s)
- Agustín Mangiarotti
- Max Planck Institute of Colloids and Interfaces, Science Park Golm, Potsdam, Germany.
| | - Rumiana Dimova
- Max Planck Institute of Colloids and Interfaces, Science Park Golm, Potsdam, Germany.
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4
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Aguilar J, Malacrida L, Gunther G, Torrado B, Torres V, Urbano BF, Sánchez SA. Cells immersed in collagen matrices show a decrease in plasma membrane fluidity as the matrix stiffness increases. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2023; 1865:184176. [PMID: 37328024 DOI: 10.1016/j.bbamem.2023.184176] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 05/10/2023] [Accepted: 05/15/2023] [Indexed: 06/18/2023]
Abstract
Cells are constantly adapting to maintain their identity in response to the surrounding media's temporal and spatial heterogeneity. The plasma membrane, which participates in the transduction of external signals, plays a crucial role in this adaptation. Studies suggest that nano and micrometer areas with different fluidities at the plasma membrane change their distribution in response to external mechanical signals. However, investigations linking fluidity domains with mechanical stimuli, specifically matrix stiffness, are still in progress. This report tests the hypothesis that the stiffness of the extracellular matrix can modify the equilibrium of areas with different order in the plasma membrane, resulting in changes in overall membrane fluidity distribution. We studied the effect of matrix stiffness on the distribution of membrane lipid domains in NIH-3 T3 cells immersed in matrices of varying concentrations of collagen type I, for 24 or 72 h. The stiffness and viscoelastic properties of the collagen matrices were characterized by rheometry, fiber sizes were measured by Scanning Electron Microscopy (SEM) and the volume occupied by the fibers by second harmonic generation imaging (SHG). Membrane fluidity was measured using the fluorescent dye LAURDAN and spectral phasor analysis. The results demonstrate that an increase in collagen stiffness alters the distribution of membrane fluidity, leading to an increasing amount of the LAURDAN fraction with a high degree of packing. These findings suggest that changes in the equilibrium of fluidity domains could represent a versatile and refined component of the signal transduction mechanism for cells to respond to the highly heterogeneous matrix structural composition. Overall, this study sheds light on the importance of the plasma membrane's role in adapting to the extracellular matrix's mechanical cues.
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Affiliation(s)
- Joao Aguilar
- Laboratorio de Interacciones Macromoleculares (LIMM), Departamento de Polímeros, Facultad de Ciencias Químicas, Universidad de Concepción, Concepción, Chile
| | - Leonel Malacrida
- Departamento de Fisiopatología, Hospital de Clínicas, Universidad de la República, Montevideo, Uruguay; Advanced Bioimaging Unit, Institut Pasteur Montevideo, Universidad de la República, Montevideo, Uruguay
| | - German Gunther
- Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Chile
| | - Belén Torrado
- Biomedical Engineering Department, University of California at Irvine, California, USA
| | - Viviana Torres
- Departamento de Bioquímica, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Bruno F Urbano
- Laboratorio de Interacciones Macromoleculares (LIMM), Departamento de Polímeros, Facultad de Ciencias Químicas, Universidad de Concepción, Concepción, Chile
| | - Susana A Sánchez
- Laboratorio de Interacciones Macromoleculares (LIMM), Departamento de Polímeros, Facultad de Ciencias Químicas, Universidad de Concepción, Concepción, Chile.
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5
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Jayawardena BM, Menon R, Jones MR, Jones CE. Spectral Phasor Analysis of Nile Red Identifies Membrane Microenvironment Changes in the Presence of Amyloid Peptides. Cell Biochem Biophys 2023; 81:19-27. [PMID: 36203076 DOI: 10.1007/s12013-022-01105-0] [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: 05/22/2022] [Accepted: 09/24/2022] [Indexed: 11/29/2022]
Abstract
The interaction of protein and peptide amyloid oligomers with membranes is thought to be one of the mechanisms contributing to cellular toxicity. However, techniques to study these interactions in the complex membrane environment of live cells are lacking. Spectral phasor analysis is a recently developed biophysical technique that can enable visualisation and analysis of membrane-associated fluorescent dyes. When the spectral profile of these dyes changes as a result of changes to the membrane microenvironment, spectral phasor analysis can localise those changes to discrete membrane regions. In this study, we investigated whether spectral phasor analysis could detect changes in the membrane microenvironment of live cells in the presence of fibrillar aggregates of the disease-related Aβ42 peptide or the functional amyloid neurokinin B. Our results show that the fibrils cause distinct changes to the microenvironment of nile red associated with both the plasma and the nuclear membrane. We attribute these shifts in nile red spectral properties to changes in membrane fluidity. Results from this work suggest that cells have mechanisms to avoid or control membrane interactions arising from functional amyloids which have implications for how these peptides are stored in dense core vesicles. Furthermore, the work highlights the utility of spectral phasor analysis to monitor microenvironment changes to fluorescent probes in live cells.
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Affiliation(s)
- Bhawantha M Jayawardena
- School of Science, Western Sydney University, Locked Bag 1797, Penrith, 2751, NSW, Australia
| | - Resmi Menon
- School of Science, Western Sydney University, Locked Bag 1797, Penrith, 2751, NSW, Australia.,PYC Therapeutics, QEII Medical Centre, 6 Verdun St, Nedlands, 6009, WA, Australia
| | - Mark R Jones
- School of Science, Western Sydney University, Locked Bag 1797, Penrith, 2751, NSW, Australia
| | - Christopher E Jones
- School of Science, Western Sydney University, Locked Bag 1797, Penrith, 2751, NSW, Australia.
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6
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Pradhan SS, Rao KR, Manjunath M, Saiswaroop R, Patnana DP, Phalguna KS, Choudhary B, Sivaramakrishnan V. Vitamin B 6, B 12 and folate modulate deregulated pathways and protein aggregation in yeast model of Huntington disease. 3 Biotech 2023; 13:96. [PMID: 36852176 PMCID: PMC9958225 DOI: 10.1007/s13205-023-03525-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 02/13/2023] [Indexed: 03/01/2023] Open
Abstract
Huntington's disease (HD) is an incurable and progressive neurodegenerative disease affecting the basal ganglia of the brain. HD is caused due to expansion of the polyglutamine tract in the protein Huntingtin resulting in aggregates. The increased PolyQ length results in aggregation of protein Huntingtin leading to neuronal cell death. Vitamin B6, B12 and folate are deficient in many neurodegenerative diseases. We performed an integrated analysis of transcriptomic, metabolomic and cofactor-protein network of vitamin B6, B12 and folate was performed. Our results show considerable overlap of pathways modulated by Vitamin B6, B12 and folate with those obtained from transcriptomic and metabolomic data of HD patients and model systems. Further, in yeast model of HD we showed treatment of B6, B12 or folate either alone or in combination showed impaired aggregate formation. Transcriptomic analysis of yeast model treated with B6, B12 and folate showed upregulation of pathways like ubiquitin mediated proteolysis, autophagy, peroxisome, fatty acid, lipid and nitrogen metabolism. Metabolomic analysis of yeast model shows deregulation of pathways like aminoacyl-tRNA biosynthesis, metabolism of various amino acids, nitrogen metabolism and glutathione metabolism. Integrated transcriptomic and metabolomic analysis of yeast model showed concordance in the pathways obtained. Knockout of Peroxisomal (PXP1 and PEX7) and Autophagy (ATG5) genes in yeast increased aggregates which is mitigated by vitamin B6, B12 and folate treatment. Taken together our results show a role for Vitamin B6, B12 and folate mediated modulation of pathways important for preventing protein aggregation with potential implications for HD. Supplementary Information The online version contains supplementary material available at 10.1007/s13205-023-03525-y.
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Affiliation(s)
- Sai Sanwid Pradhan
- Disease Biology Lab, Department of Biosciences, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Anantapur, Andhra Pradesh 515134 India
| | - K. Raksha Rao
- Institute of Bioinformatics and Applied Biotechnology, Bangalore, Karnataka 560100 India
| | - Meghana Manjunath
- Institute of Bioinformatics and Applied Biotechnology, Bangalore, Karnataka 560100 India
| | - R. Saiswaroop
- Disease Biology Lab, Department of Biosciences, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Anantapur, Andhra Pradesh 515134 India
| | - Durga Prasad Patnana
- Department of Chemistry, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Anantapur, Andhra Pradesh 515134 India
| | - Kanikaram Sai Phalguna
- Disease Biology Lab, Department of Biosciences, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Anantapur, Andhra Pradesh 515134 India
| | - Bibha Choudhary
- Institute of Bioinformatics and Applied Biotechnology, Bangalore, Karnataka 560100 India
| | - Venketesh Sivaramakrishnan
- Disease Biology Lab, Department of Biosciences, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Anantapur, Andhra Pradesh 515134 India
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7
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Farzana F, McConville MJ, Renoir T, Li S, Nie S, Tran H, Hannan AJ, Hatters DM, Boughton BA. Longitudinal spatial mapping of lipid metabolites reveals pre-symptomatic changes in the hippocampi of Huntington's disease transgenic mice. Neurobiol Dis 2023; 176:105933. [PMID: 36436748 DOI: 10.1016/j.nbd.2022.105933] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 11/16/2022] [Accepted: 11/23/2022] [Indexed: 11/26/2022] Open
Abstract
In Huntington's disease (HD), a key pathological feature includes the development of inclusion-bodies of fragments of the mutant huntingtin protein in the neurons of the striatum and hippocampus. To examine the molecular changes associated with inclusion-body formation, we applied MALDI-mass spectrometry imaging and deuterium pulse labelling to determine lipid levels and synthesis rates in the hippocampus of a transgenic mouse model of HD (R6/1 line). The R6/1 HD mice lacked inclusions in the hippocampus at 6 weeks of age (pre-symptomatic), whereas inclusions were pervasive by 16 weeks of age (symptomatic). Hippocampal subfields (CA1, CA3 and DG), which formed the highest density of inclusion formation in the mouse brain showed a reduction in the relative abundance of neuron-enriched lipids that have roles in neurotransmission, synaptic plasticity, neurogenesis, and ER-stress protection. Lipids involved in the adaptive response to ER stress (phosphatidylinositol, phosphatidic acid, and ganglioside classes) displayed increased rates of synthesis in HD mice relative to WT mice at all the ages examined, including prior to the formation of the inclusion bodies. Our findings, therefore, support a role for ER stress occurring pre-symptomatically and potentially contributing to pathological mechanisms underlying HD.
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Affiliation(s)
- Farheen Farzana
- Florey Institute of Neuroscience & Mental Health, The University of Melbourne, Victoria 3010, Australia; Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria 3010, Australia
| | - Malcolm J McConville
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria 3010, Australia; Metabolomics Australia, The University of Melbourne, Victoria 3010, Australia
| | - Thibault Renoir
- Florey Institute of Neuroscience & Mental Health, The University of Melbourne, Victoria 3010, Australia
| | - Shanshan Li
- Florey Institute of Neuroscience & Mental Health, The University of Melbourne, Victoria 3010, Australia
| | - Shuai Nie
- Melbourne Mass Spectrometry and Proteomics Facility, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria 3010, Australia
| | - Harvey Tran
- Florey Institute of Neuroscience & Mental Health, The University of Melbourne, Victoria 3010, Australia
| | - Anthony J Hannan
- Florey Institute of Neuroscience & Mental Health, The University of Melbourne, Victoria 3010, Australia.
| | - Danny M Hatters
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria 3010, Australia.
| | - Berin A Boughton
- School of Biosciences, The University of Melbourne, Victoria 3010, Australia; Australian National Phenome Centre, Murdoch University, Murdoch 6150, Western Australia, Australia.
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8
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McDonald TS, Lerskiatiphanich T, Woodruff TM, McCombe PA, Lee JD. Potential mechanisms to modify impaired glucose metabolism in neurodegenerative disorders. J Cereb Blood Flow Metab 2023; 43:26-43. [PMID: 36281012 PMCID: PMC9875350 DOI: 10.1177/0271678x221135061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 09/01/2022] [Accepted: 09/21/2022] [Indexed: 01/28/2023]
Abstract
Neurodegeneration refers to the selective and progressive loss-of-function and atrophy of neurons, and is present in disorders such as Alzheimer's, Huntington's, and Parkinson's disease. Although each disease presents with a unique pattern of neurodegeneration, and subsequent disease phenotype, increasing evidence implicates alterations in energy usage as a shared and core feature in the onset and progression of these disorders. Indeed, disturbances in energy metabolism may contribute to the vulnerability of neurons to apoptosis. In this review we will outline these disturbances in glucose metabolism, and how fatty acids are able to compensate for this impairment in energy production in neurodegenerative disorders. We will also highlight underlying mechanisms that could contribute to these alterations in energy metabolism. A greater understanding of these metabolism-neurodegeneration processes could lead to improved treatment options for neurodegenerative disease patients.
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Affiliation(s)
- Tanya S McDonald
- School of Biomedical Sciences, Faculty of Medicine, The
University of Queensland, St. Lucia, Australia
| | - Titaya Lerskiatiphanich
- School of Biomedical Sciences, Faculty of Medicine, The
University of Queensland, St. Lucia, Australia
| | - Trent M Woodruff
- School of Biomedical Sciences, Faculty of Medicine, The
University of Queensland, St. Lucia, Australia
- Queensland Brain Institute, The University of Queensland, St.
Lucia, Australia
| | - Pamela A McCombe
- Centre for Clinical Research, Faculty of Medicine, The
University of Queensland, St. Lucia, Australia
- Department of Neurology, Royal Brisbane & Women’s Hospital,
Herston, Australia
| | - John D Lee
- School of Biomedical Sciences, Faculty of Medicine, The
University of Queensland, St. Lucia, Australia
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9
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Díaz M, Malacrida L. Advanced Fluorescence Microscopy Methods to Study Dynamics of Fluorescent Proteins In Vivo. Methods Mol Biol 2023; 2564:53-74. [PMID: 36107337 DOI: 10.1007/978-1-0716-2667-2_3] [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] [Indexed: 06/15/2023]
Abstract
Fluorescent proteins are standard tools for addressing biological questions in a cell biology laboratory. The genetic tagging of protein of interest with fluorescent proteins opens the opportunity to follow them in vivo and to understand their interactions and dynamics. In addition, the latest advances in optical microscopy image acquisition and processing allow us to study many cellular processes in vivo. Techniques such as fluorescence lifetime microscopy and hyperspectral imaging provide valuable tools for understanding fluorescent protein interactions and their photophysics. Finally, fluorescence fluctuation analysis opens the possibility to address questions of molecular diffusion, protein-protein interactions, and oligomerization, among others, yielding quantitative information on the subject of study. This chapter will cover some of the more important advances in cutting-edge technologies and methods that, combined with fluorescent proteins, open new frontiers for biological studies.
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Affiliation(s)
- Marcela Díaz
- Advanced Bioimaging Unit, Institut Pasteur of Montevideo & Universidad de la República, Montevideo, Uruguay
| | - Leonel Malacrida
- Advanced Bioimaging Unit, Institut Pasteur of Montevideo & Universidad de la República, Montevideo, Uruguay.
- Departamento de Fisiopatología, Hospital de Clínicas, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay.
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10
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Ruiz M, Svensk E, Einarsson E, Grahn EP, Pilon M. A small molecule screen for paqr-2 suppressors identifies Tyloxapol as a membrane fluidizer for C. elegans and mammalian cells. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:183959. [PMID: 35588889 DOI: 10.1016/j.bbamem.2022.183959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 04/20/2022] [Accepted: 05/04/2022] [Indexed: 06/15/2023]
Abstract
Defects in cell membrane homeostasis are implicated in numerous disorders, including cancer, neurodegeneration and diabetes. There is therefore a need for a powerful model to study membrane homeostasis and to identify eventual therapeutic routes. The C. elegans gene paqr-2 encodes a homolog of the mammalian AdipoR1 and AdipoR2 proteins that, when mutated, causes a membrane homeostasis defect accompanied by multiple phenotypes such as intolerance to dietary saturated fatty acids, intolerance to cold and a characteristic tail tip morphology defect. We screened a compound library to identify molecules that can suppress the paqr-2 phenotypes. A single positive hit, Tyloxapol, was found that very effectively suppresses multiple paqr-2 phenotypes. Tyloxapol is a non-ionic detergent currently in use clinically as an expectorant. Importantly, we examined the potential of Tyloxapol as a fluidizer in human cells and found that it improves the viability and membrane fluidity of AdipoR2-deficient human cells challenged with palmitic acid, a membrane-rigidifying saturated fatty acid.
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Affiliation(s)
- Mario Ruiz
- Dept. Chemistry and Molecular Biology, University of Gothenburg, Medicinaregatan 9C, S-405 30 Gothenburg, Sweden
| | - Emma Svensk
- Dept. Chemistry and Molecular Biology, University of Gothenburg, Medicinaregatan 9C, S-405 30 Gothenburg, Sweden
| | - Elinor Einarsson
- Dept. Chemistry and Molecular Biology, University of Gothenburg, Medicinaregatan 9C, S-405 30 Gothenburg, Sweden
| | - Erik Podda Grahn
- Dept. Chemistry and Molecular Biology, University of Gothenburg, Medicinaregatan 9C, S-405 30 Gothenburg, Sweden
| | - Marc Pilon
- Dept. Chemistry and Molecular Biology, University of Gothenburg, Medicinaregatan 9C, S-405 30 Gothenburg, Sweden.
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11
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Jin CY, Yu SW, Yin JT, Yuan XY, Wang XG. Corresponding risk factors between cognitive impairment and type 1 diabetes mellitus: a narrative review. Heliyon 2022; 8:e10073. [PMID: 35991978 PMCID: PMC9389196 DOI: 10.1016/j.heliyon.2022.e10073] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 04/24/2022] [Accepted: 07/20/2022] [Indexed: 11/30/2022] Open
Abstract
Type 1 diabetes mellitus (T1DM) is a type of diabetes caused by the destruction of pancreatic β cells and the absolute lack of insulin secretion. T1DM usually starts in adolescence or develops directly as a severe disease state of ketoacidosis. T1DM and its complications make many people suffer and have psychological problems, which make us have to pay more attention to the prevention and early control of T1DM. Cognitive impairment (CI) is one of the major complications of T1DM. It can further develop into Alzheimer's disease, which can seriously affect the quality of life of the elderly. Furthermore, the relationship between T1DM and CI is unclear. Hence, we conducted a narrative review of the existing literature through a PubMed search. We summarized some risk factors that may be associated with the cognitive changes in T1DM patients, including onset age and duration, education and gender, glycemic states, microvascular complications, glycemic control, neuropsychology and emotion, intestinal flora, dyslipidemia, sleep quality. We aimed to provide some content related to CI in T1DM, and hoped that it could play a role in early prediction and treatment to reduce the prevalence. Corresponding risk factors between cognitive impairment and type 1 diabetes mellitus. Duration and age; Education and gender and Glycemic states. Diabetic ketoacidosis; Microvascular complications and Glycemic control–HbA1c. Neuropsychology and emotion; Intestinal flora; Dyslipidemia and Sleep Quality.
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Affiliation(s)
- Chen-Yang Jin
- The First Affiliated Hospital of Dalian Medical University, Dalian Medical University, Dalian 116011, PR China
| | - Shi-Wen Yu
- The First Affiliated Hospital of Dalian Medical University, Dalian Medical University, Dalian 116011, PR China
| | - Jun-Ting Yin
- The Second Affiliated Hospital of Dalian Medical University, Dalian Medical University, Dalian 116027, PR China
| | - Xiao-Ying Yuan
- Department of Anatomy, College of Basic Medicine, Dalian Medical University, Dalian 116044, PR China
- Department of Surgery, The Affiliated Zhongshan Hospital of Dalian University, Dalian 116001, PR China
- Corresponding author.
| | - Xu-Gang Wang
- Department of Neurology, The Second Affiliated Hospital of Dalian Medical University, Dalian 116027, PR China
- Corresponding author.
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12
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Dadhich R, Kapoor S. Lipidomic and Membrane Mechanical Signatures in Triple-Negative Breast Cancer: Scope for Membrane-Based Theranostics. Mol Cell Biochem 2022; 477:2507-2528. [PMID: 35595957 DOI: 10.1007/s11010-022-04459-4] [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: 09/28/2021] [Accepted: 04/28/2022] [Indexed: 10/18/2022]
Abstract
Triple-negative breast cancer (TNBC) is a highly aggressive form of breast cancer associated with poor prognosis, higher grade, and a high rate of metastatic occurrence. Limited therapeutic interventions and the compounding issue of drug resistance in triple-negative breast cancer warrants the discovery of novel therapeutic targets and diagnostic modules. To this view, in addition to proteins, lipids also regulate cellular functions via the formation of membranes that modulate membrane protein function, diffusion, and their localization; thus, orchestrating signaling hot spots enriched in specific lipids/proteins on cell membranes. Lipid deregulation in cancer leads to reprogramming of the membrane dynamics and functions impacting cell proliferation, metabolism, and metastasis, providing exciting starting points for developing lipid-based approaches for treating TNBC. In this review, we provide a detailed account of specific lipidic changes in breast cancer, link the altered lipidome with membrane structure and mechanical properties, and describe how these are linked to subsequent downstream functions implicit in cancer progression, metastasis, and chemoresistance. At the fundamental level, we discuss how the lipid-centric findings in TNBC are providing cues for developing lipid-inspired theranostic strategies while bridging existing gaps in our understanding of the functional involvement of lipid membranes in cancer.
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Affiliation(s)
- Ruchika Dadhich
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, 400076, India
| | - Shobhna Kapoor
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, 400076, India. .,Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, 739-8528, Japan.
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13
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Vorontsova I, Vallmitjana A, Torrado B, Schilling TF, Hall JE, Gratton E, Malacrida L. In vivo macromolecular crowding is differentially modulated by aquaporin 0 in zebrafish lens: Insights from a nanoenvironment sensor and spectral imaging. SCIENCE ADVANCES 2022; 8:eabj4833. [PMID: 35171678 PMCID: PMC8849302 DOI: 10.1126/sciadv.abj4833] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 12/23/2021] [Indexed: 05/14/2023]
Abstract
Macromolecular crowding is crucial for cellular homeostasis. In vivo studies of macromolecular crowding and water dynamics are needed to understand their roles in cellular physiology and fate determination. Macromolecular crowding in the lens is essential for normal optics, and an understanding of its regulation will help prevent cataract and presbyopia. Here, we combine the use of the nanoenvironmental sensor [6-acetyl-2-dimethylaminonaphthalene (ACDAN)] to visualize lens macromolecular crowding with in vivo studies of aquaporin 0 zebrafish mutants that disrupt its regulation. Spectral phasor analysis of ACDAN fluorescence reveals water dipolar relaxation and demonstrates that mutations in two zebrafish aquaporin 0s, Aqp0a and Aqp0b, alter water state and macromolecular crowding in living lenses. Our results provide in vivo evidence that Aqp0a promotes fluid influx in the deeper lens cortex, whereas Aqp0b facilitates fluid efflux. This evidence reveals previously unidentified spatial regulation of macromolecular crowding and spatially distinct roles for Aqp0 in the lens.
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Affiliation(s)
- Irene Vorontsova
- Physiology and Biophysics, University of California, Irvine, Irvine, CA, USA
- Developmental and Cell Biology, University of California, Irvine, Irvine, CA, USA
- Neurobiology and Behavior, University of California, Irvine, Irvine, CA, USA
| | | | - Belén Torrado
- Biomedical Engineering, University of California, Irvine, Irvine, CA, USA
| | - Thomas F. Schilling
- Developmental and Cell Biology, University of California, Irvine, Irvine, CA, USA
| | - James E. Hall
- Physiology and Biophysics, University of California, Irvine, Irvine, CA, USA
| | - Enrico Gratton
- Biomedical Engineering, University of California, Irvine, Irvine, CA, USA
| | - Leonel Malacrida
- Departamento de Fisiopatología, Hospital de Clínicas, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
- Advanced Bioimaging Unit, Institut Pasteur of Montevideo and Universidad de la República, Montevideo, Uruguay
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14
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Linear Combination Properties of the Phasor Space in Fluorescence Imaging. SENSORS 2022; 22:s22030999. [PMID: 35161742 PMCID: PMC8840623 DOI: 10.3390/s22030999] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 01/15/2022] [Accepted: 01/20/2022] [Indexed: 12/16/2022]
Abstract
The phasor approach to fluorescence lifetime imaging, and more recently hyperspectral fluorescence imaging, has increased the use of these techniques, and improved the ease and intuitiveness of the data analysis. The fit-free nature of the phasor plots increases the speed of the analysis and reduces the dimensionality, optimization of data handling and storage. The reciprocity principle between the real and imaginary space-where the phasor and the pixel that the phasor originated from are linked and can be converted from one another-has helped the expansion of this method. The phasor coordinates calculated from a pixel, where multiple fluorescent species are present, depends on the phasor positions of those components. The relative positions are governed by the linear combination properties of the phasor space. According to this principle, the phasor position of a pixel with multiple components lies inside the polygon whose vertices are occupied by the phasor positions of these individual components and the distance between the image phasor to any of the vertices is inversely proportional to the fractional intensity contribution of that component to the total fluorescence from that image pixel. The higher the fractional intensity contribution of a vertex, the closer is the resultant phasor. The linear additivity in the phasor space can be exploited to obtain the fractional intensity contribution from multiple species and quantify their contribution. This review details the various mathematical models that can be used to obtain two/three/four components from phasor space with known phasor signatures and then how to obtain both the fractional intensities and phasor positions without any prior knowledge of either, assuming they are mono-exponential in nature. We note that other than for blind components, there are no restrictions on the type of the decay or their phasor positions for linear combinations to be valid-and they are applicable to complicated fluorescence lifetime decays from components with intensity decays described by multi-exponentials.
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15
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Anselmo S, Sancataldo G, Mørck Nielsen H, Foderà V, Vetri V. Peptide-Membrane Interactions Monitored by Fluorescence Lifetime Imaging: A Study Case of Transportan 10. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:13148-13159. [PMID: 34714654 PMCID: PMC8582253 DOI: 10.1021/acs.langmuir.1c02392] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 10/19/2021] [Indexed: 06/13/2023]
Abstract
The interest on detailed analysis of peptide-membrane interactions is of great interest in both fundamental and applied sciences as these may relate to both functional and pathogenic events. Such interactions are highly dynamic and spatially heterogeneous, making the investigation of the associated phenomena highly complex. The specific properties of membranes and peptide structural details, together with environmental conditions, may determine different events at the membrane interface, which will drive the fate of the peptide-membrane system. Here, we use an experimental approach based on the combination of spectroscopy and fluorescence microscopy methods to characterize the interactions of the multifunctional amphiphilic peptide transportan 10 with model membranes. Our approach, based on the use of suitable fluorescence reporters, exploits the advantages of phasor plot analysis of fluorescence lifetime imaging microscopy measurements to highlight the molecular details of occurring membrane alterations in terms of rigidity and hydration. Simultaneously, it allows following dynamic events in real time without sample manipulation distinguishing, with high spatial resolution, whether the peptide is adsorbed to or inserted in the membrane.
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Affiliation(s)
- Sara Anselmo
- Dipartimento
di Fisica e Chimica−Emilio Segré, Università degli Studi di Palermo, Viale delle Scienze ed. 18 90128, Palermo, Italy
| | - Giuseppe Sancataldo
- Dipartimento
di Fisica e Chimica−Emilio Segré, Università degli Studi di Palermo, Viale delle Scienze ed. 18 90128, Palermo, Italy
| | - Hanne Mørck Nielsen
- Department
of Pharmacy, University of Copenhagen, Universitetsparken 2 2100, Copenhagen, Denmark
| | - Vito Foderà
- Department
of Pharmacy, University of Copenhagen, Universitetsparken 2 2100, Copenhagen, Denmark
| | - Valeria Vetri
- Dipartimento
di Fisica e Chimica−Emilio Segré, Università degli Studi di Palermo, Viale delle Scienze ed. 18 90128, Palermo, Italy
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16
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Lepanto P, Levin-Ferreyra F, Koziol U, Malacrida L, Badano JL. Insights into in vivo adipocyte differentiation through cell-specific labeling in zebrafish. Biol Open 2021; 10:271875. [PMID: 34409430 PMCID: PMC8443861 DOI: 10.1242/bio.058734] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 08/10/2021] [Indexed: 01/04/2023] Open
Abstract
White adipose tissue hyperplasia has been shown to be crucial for handling excess energy in healthy ways. Though adipogenesis mechanisms have been underscored in vitro, we lack information on how tissue and systemic factors influence the differentiation of new adipocytes. While this could be studied in zebrafish, adipocyte identification currently relies on neutral lipid labeling, thus precluding access to cells in early stages of differentiation. Here we report the generation and analysis of a zebrafish line with the transgene fabp4a(-2.7):EGFPcaax. In vivo confocal microscopy of the pancreatic and abdominal visceral depots of transgenic larvae, revealed the presence of labeled mature adipocytes as well as immature cells in earlier stages of differentiation. Through co-labeling for blood vessels, we observed a close interaction of differentiating adipocytes with endothelial cells through cell protrusions. Finally, we implemented hyperspectral imaging and spectral phasor analysis in Nile Red-labeled transgenic larvae and revealed the lipid metabolic transition towards neutral lipid accumulation of differentiating adipocytes. Altogether our work presents the characterization of a novel adipocyte-specific label in zebrafish and uncovers previously unknown aspects of in vivo adipogenesis. This article has an associated First Person interview with the first author of the paper. Summary: Analysis of the differentiation of adipocytes in vivo through cell-specific labeling in zebrafish, revealed their early interaction with blood vessels as well as early lipid metabolic changes.
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Affiliation(s)
- Paola Lepanto
- Human Molecular Genetics Lab, Institut Pasteur de Montevideo, Montevideo, Mataojo 2020, CP11400, Uruguay
| | - Florencia Levin-Ferreyra
- Human Molecular Genetics Lab, Institut Pasteur de Montevideo, Montevideo, Mataojo 2020, CP11400, Uruguay
| | - Uriel Koziol
- Sección Biología Celular, Facultad de Ciencias, Universidad de la República, Montevideo, Igua 4225, CP11400, Uruguay
| | - Leonel Malacrida
- Advanced Bioimaging Unit, Institut Pasteur de Montevideo and Universidad de la República, Montevideo, Mataojo 2020, CP11400, Uruguay.,Departamento de Fisiopatología, Hospital de Clínicas, Facultad de Medicina, Universidad de la República, Montevideo, Av. Italia s/n, CP11600, Uruguay
| | - José L Badano
- Human Molecular Genetics Lab, Institut Pasteur de Montevideo, Montevideo, Mataojo 2020, CP11400, Uruguay
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17
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Abstract
The miniSPIM is a miniaturized light-sheet microscope that enables imaging with optical sectioning on mobile camera devices such as smartphones and single-board computers. Applications of the miniSPIM include biosensing, field research, and education where maximum portability and robustness, low power consumption, and low cost are key. Here, it is shown how all of the components of a simple light-sheet microscope can be integrated within a footprint smaller than the average smartphone. Example applications include the quantification of the motion of microparticles and bacteria in fluids, the characterization of solvent polarity based on spectral shifts of the lipid probe Nile Red, and three-dimensional (3D) and time-lapse autofluorescence imaging of a live zebrafish embryo.
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Affiliation(s)
- Per Niklas Hedde
- Beckman Laser Institute, University of California Irvine, Irvine, California 92612, United States
- Department of Pharmaceutical Sciences, University of California Irvine, Irvine, California 92697, United States
- Laboratory for Fluorescence Dynamics, University of California Irvine, Irvine, California 92697, United States
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18
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Malacrida L, Ranjit S, Jameson DM, Gratton E. The Phasor Plot: A Universal Circle to Advance Fluorescence Lifetime Analysis and Interpretation. Annu Rev Biophys 2021; 50:575-593. [PMID: 33957055 DOI: 10.1146/annurev-biophys-062920-063631] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The phasor approach to fluorescence lifetime imaging has become a common method to analyze complicated fluorescence signals from biological samples. The appeal of the phasor representation of complex fluorescence decays in biological systems is that a visual representation of the decay of entire cells or tissues can be used to easily interpret fundamental biological states related to metabolism and oxidative stress. Phenotyping based on autofluorescence provides new avenues for disease characterization and diagnostics. The phasor approach is a transformation of complex fluorescence decays that does not use fits to model decays and therefore has the same information content as the original data. The phasor plot is unique for a given system, is highly reproducible, and provides a robust method to evaluate the existence of molecular interactions such as Förster resonance energy transfer or the response of ion indicators. Recent advances permitquantification of multiple components from phasor plots in fluorescence lifetime imaging microscopy, which is not presently possible using data fitting methods, especially in biological systems.
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Affiliation(s)
- Leonel Malacrida
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California, Irvine, California 92697, USA; .,Departamento de Fisiopatología, Hospital de Clínicas, Facultad de Medicina, Universidad de la República, 11600 Montevideo, Uruguay.,Advanced Bioimaging Unit, Institut Pasteur Montevideo and Universidad de la República-Uruguay, 11400 Montevideo, Uruguay
| | - Suman Ranjit
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California, Irvine, California 92697, USA; .,Department of Biochemistry and Molecular & Cellular Biology, Georgetown University, Washington, DC 20057, USA
| | - David M Jameson
- Department of Cell and Molecular Biology, University of Hawaii at Manoa, Honolulu, Hawaii 96813, USA
| | - Enrico Gratton
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California, Irvine, California 92697, USA;
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19
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Pilon M. Paradigm shift: the primary function of the "Adiponectin Receptors" is to regulate cell membrane composition. Lipids Health Dis 2021; 20:43. [PMID: 33931104 PMCID: PMC8088037 DOI: 10.1186/s12944-021-01468-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 04/18/2021] [Indexed: 12/13/2022] Open
Abstract
The ADIPOR1 and ADIPOR2 proteins (ADIPORs) are generally considered as adiponectin receptors with anti-diabetic properties. However, studies on the yeast and C. elegans homologs of the mammalian ADIPORs, and of the ADIPORs themselves in various mammalian cell models, support an updated/different view. Based on findings in these experimental models, the ADIPORs are now emerging as evolutionarily conserved regulators of membrane homeostasis that do not require adiponectin to act as membrane fluidity sensors and regulate phospholipid composition. More specifically, membrane rigidification activates ADIPOR signaling to promote fatty acid desaturation and incorporation of polyunsaturated fatty acids into membrane phospholipids until fluidity is restored. The present review summarizes the evidence supporting this new view of the ADIPORs, and briefly examines physiological consequences.
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Affiliation(s)
- Marc Pilon
- Dept. Chemistry and Molecular Biology, Univ. Gothenburg, Box 462, S-405 30, Gothenburg, Sweden.
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20
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Zou X, Himbert S, Dujardin A, Juhasz J, Ros S, Stöver HDH, Rheinstädter MC. Curcumin and Homotaurine Suppress Amyloid-β 25-35 Aggregation in Synthetic Brain Membranes. ACS Chem Neurosci 2021; 12:1395-1405. [PMID: 33826295 DOI: 10.1021/acschemneuro.1c00057] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Amyloid-β (Aβ) peptides spontaneously aggregate into β- and cross-β-sheets in model brain membranes. These nanometer sized can fuse into larger micrometer sized clusters and become extracellular and serve as nuclei for further plaque and fibril growth. Curcumin and homotaurine represent two different types of Aβ aggregation inhibitors. While homotaurine is a peptic antiaggregant that binds to amyloid peptides, curcumin is a nonpeptic molecule that can inhibit aggregation by changing membrane properties. By using optical and fluorescent microscopy, X-ray diffraction, and UV-vis spectroscopy, we study the effect of curcumin and homotaurine on Aβ25-35 aggregates in synthetic brain membranes. Both molecules partition spontaneously and uniformly in membranes and do not lead to observable membrane defects or disruption in our experiments. Both curcumin and homotaurine were found to significantly reduce the number of small, nanoscopic Aβ aggregates and the corresponding β- and cross-β-sheet signals. While a number of research projects focus on potential drug candidates that target Aβ peptides directly, membrane-lipid therapy explores membrane-mediated pathways to suppress peptide aggregation. Based on the results obtained, we conclude that membrane active drugs can be as efficient as peptide targeting drugs in inhibiting amyloid aggregation in vitro.
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Affiliation(s)
- Xingyuan Zou
- Department of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4M1, Canada
- Origins Institute, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Sebastian Himbert
- Department of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4M1, Canada
- Origins Institute, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Alix Dujardin
- Department of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4M1, Canada
- Origins Institute, McMaster University, Hamilton, ON L8S 4L8, Canada
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Janos Juhasz
- Department of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4M1, Canada
- Department of Medical Physics, Juravinski Cancer Centre, Hamilton, ON L8V 5C2, Canada
| | - Samantha Ros
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Harald D. H. Stöver
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Maikel C. Rheinstädter
- Department of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4M1, Canada
- Origins Institute, McMaster University, Hamilton, ON L8S 4L8, Canada
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21
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Ammendolia DA, Bement WM, Brumell JH. Plasma membrane integrity: implications for health and disease. BMC Biol 2021; 19:71. [PMID: 33849525 PMCID: PMC8042475 DOI: 10.1186/s12915-021-00972-y] [Citation(s) in RCA: 89] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Accepted: 02/01/2021] [Indexed: 12/12/2022] Open
Abstract
Plasma membrane integrity is essential for cellular homeostasis. In vivo, cells experience plasma membrane damage from a multitude of stressors in the extra- and intra-cellular environment. To avoid lethal consequences, cells are equipped with repair pathways to restore membrane integrity. Here, we assess plasma membrane damage and repair from a whole-body perspective. We highlight the role of tissue-specific stressors in health and disease and examine membrane repair pathways across diverse cell types. Furthermore, we outline the impact of genetic and environmental factors on plasma membrane integrity and how these contribute to disease pathogenesis in different tissues.
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Affiliation(s)
- Dustin A Ammendolia
- Cell Biology Program, Hospital for Sick Children, 686 Bay Street PGCRL, Toronto, ON, M5G 0A4, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A1, Canada
| | - William M Bement
- Center for Quantitative Cell Imaging and Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - John H Brumell
- Cell Biology Program, Hospital for Sick Children, 686 Bay Street PGCRL, Toronto, ON, M5G 0A4, Canada. .,Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A1, Canada. .,Institute of Medical Science, University of Toronto, Toronto, ON, M5S 1A1, Canada. .,SickKids IBD Centre, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada.
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22
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Gunther G, Malacrida L, Jameson DM, Gratton E, Sánchez SA. LAURDAN since Weber: The Quest for Visualizing Membrane Heterogeneity. Acc Chem Res 2021; 54:976-987. [PMID: 33513300 PMCID: PMC8552415 DOI: 10.1021/acs.accounts.0c00687] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Any chemist studying the interaction of molecules with lipid assemblies will eventually be confronted by the topic of membrane bilayer heterogeneity and may ultimately encounter the heterogeneity of natural membranes. In artificial bilayers, heterogeneity is defined by phase segregation that can be in the nano- and micrometer range. In biological bilayers, heterogeneity is considered in the context of small (10-200 nm) sterol and sphingolipid-enriched heterogeneous and highly dynamic domains. Several techniques can be used to assess membrane heterogeneity in living systems. Our approach is to use a fluorescent reporter molecule immersed in the bilayer, which, by changes in its spectroscopic properties, senses physical-chemistry aspects of the membrane. This dye in combination with microscopy and fluctuation techniques can give information about membrane heterogeneity at different temporal and spatial levels: going from average fluidity to number and diffusion coefficient of nanodomains. LAURDAN (6-dodecanoyl-2-(dimethylamino) naphthalene), is a fluorescent probe designed and synthesized in 1979 by Gregorio Weber with the purpose to study the phenomenon of dipolar relaxation. The spectral displacement observed when LAURDAN is either in fluid or gel phase permitted the use of the technique in the field of membrane dynamics. The quantitation of the spectral displacement was first addressed by the generalized polarization (GP) function in the cuvette, a ratio of the difference in intensity at two wavelengths divided by their sum. In 1997, GP measurements were done for the first time in the microscope, adding to the technique the spatial resolution and allowing the visualization of lipid segregation both in liposomes and cells. A new prospective to the membrane heterogeneity was obtained when LAURDAN fluorescent lifetime measurements were done in the microscope. Two channel lifetime imaging provides information on membrane polarity and dipole relaxation (the two parameters responsible for the spectral shift of LAURDAN), and the application of phasor analysis allows pixel by pixel understanding of these two parameters in the membrane. To increase temporal resolution, LAURDAN GP was combined with fluctuation correlation spectroscopy (FCS) and the motility of nanometric highly packed structures in biological membranes was registered. Lately the application of phasor analysis to spectral images from membranes labeled with LAURDAN allows us to study the full spectra pixel by pixel in an image. All these methodologies, using LAURDAN, offer the possibility to address different properties of membranes depending on the question being asked. In this Account, we will focus on the principles, advantages, and limitations of different approaches to orient the reader to select the most appropriate technique for their research.
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Affiliation(s)
- German Gunther
- Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Sergio Livingstone P. 1007, Santiago 8380492, Chile
| | - Leonel Malacrida
- Advanced Microscopy and Biophotonics Unit, Hospital de Clínicas, Universidad de la República, Montevideo-Uruguay. Advanced Bioimaging Unit, Institut Pasteur Montevideo, Av. Italia s/n, 90600 Montevideo, Uruguay
| | - David M Jameson
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, 651 Ilalo Street, Biosciences 222, Honolulu, Hawaii 96813, United States
| | - Enrico Gratton
- Laboratory for Fluorescence Dynamics, 3210 Natural Sciences II, University of California, Irvine, Irvine, California 92697-2725, United States
| | - Susana A Sánchez
- Departamento de Polímeros, Facultad de Ciencias Químicas, Universidad de Concepción, Edmundo Larenas 129, Concepción 4070371, Chile
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23
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Bianchetti G, Spirito MD, Maulucci G. Unsupervised clustering of multiparametric fluorescent images extends the spectrum of detectable cell membrane phases with sub-micrometric resolution. BIOMEDICAL OPTICS EXPRESS 2020; 11:5728-5744. [PMID: 33149982 PMCID: PMC7587257 DOI: 10.1364/boe.399655] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 07/09/2020] [Accepted: 07/23/2020] [Indexed: 05/08/2023]
Abstract
Solvatochromic probes undergo an emission shift when the hydration level of the membrane environment increases and are commonly used to distinguish between solid-ordered and liquid-disordered phases in artificial membrane bilayers. This emission shift is currently limited in unraveling the broad spectrum of membrane phases of natural cell membranes and their spatial organization. Spectrally resolved fluorescence lifetime imaging can provide pixel-resolved multiparametric information about the biophysical state of the membranes, like membrane hydration, microviscosity and the partition coefficient of the probe. Here, we introduce a clustering based analysis that, leveraging the multiparametric content of spectrally resolved lifetime images, allows us to classify through an unsupervised learning approach multiple membrane phases with sub-micrometric resolution. This method extends the spectrum of detectable membrane phases allowing to dissect and characterize up to six different phases, and to study real-time phase transitions in cultured cells and tissues undergoing different treatments. We applied this method to investigate membrane remodeling induced by high glucose on PC-12 neuronal cells, associated with the development of diabetic neuropathy. Due to its wide applicability, this method provides a new paradigm in the analysis of environmentally sensitive fluorescent probes.
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Affiliation(s)
- Giada Bianchetti
- Fondazione Policlinico Gemelli IRCSS, 00168
Rome, Italy
- Neuroscience Department, Biophysics
Section, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
| | - Marco De Spirito
- Fondazione Policlinico Gemelli IRCSS, 00168
Rome, Italy
- Neuroscience Department, Biophysics
Section, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
| | - Giuseppe Maulucci
- Fondazione Policlinico Gemelli IRCSS, 00168
Rome, Italy
- Neuroscience Department, Biophysics
Section, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
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24
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Proteotoxicity and Neurodegenerative Diseases. Int J Mol Sci 2020; 21:ijms21165646. [PMID: 32781742 PMCID: PMC7460676 DOI: 10.3390/ijms21165646] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 08/01/2020] [Accepted: 08/04/2020] [Indexed: 02/07/2023] Open
Abstract
Neurodegenerative diseases are a major burden for our society, affecting millions of people worldwide. A main goal of past and current research is to enhance our understanding of the mechanisms underlying proteotoxicity, a common theme among these incurable and debilitating conditions. Cell proteome alteration is considered to be one of the main driving forces that triggers neurodegeneration, and unraveling the biological complexity behind the affected molecular pathways constitutes a daunting challenge. This review summarizes the current state on key processes that lead to cellular proteotoxicity in Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis, providing a comprehensive landscape of recent literature. A foundational understanding of how proteotoxicity affects disease etiology and progression may provide essential insight towards potential targets amenable of therapeutic intervention.
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25
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Sameni S, Zhang R, Digman MA. The Phasor FLIM Method Reveals a Link Between a Change in Energy Metabolism and mHtt protein spread in Healthy Mammalian Cells when Co-cultured with Huntington Diseased Cells. Methods Appl Fluoresc 2020; 9. [PMID: 32235053 DOI: 10.1088/2050-6120/ab854d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 03/31/2020] [Indexed: 11/12/2022]
Abstract
Huntington Disease (HD) is a late-onset autosomal neurodegenerative disease characterized by the aggregations of mutant Huntingtin proteins (mHTT). A glutamine stretch (PolyQ) at the N-terminal of the Huntingtin protein is generated by the abnormal expansion of CAG trinucleotide repeats in exon 1 of the HTT gene. While the resulting polyQ aggregates are the predominate feature of HD , the intercellular spread of the expanded protein and the effect upon this transfer inside healthy cells have not yet fully understood. Here, we have employed the phasor Fluorescence Lifetime Imaging Microscopy (FLIM) method to measure NADH fluorescence lifetime change after the internalization of the PolyQ protein. Based on our analysis, we have found a significant decrease in the fraction of bound NADH in both cytoplasmic and nucleus regions when cells are co-cultured or when healthy cells uptake the supernatant containing polyQ proteins and aggregates. Overall, our FLIM study combined with confocal fluorescence imaging visualizes the absorption of the mutant Htt protein aggregates which results in a distinct NADH fluorescence lifetime between control cells and acceptor cells. These studies show, for the first time, the influence of how neighboring cells expressing the expanded Htt protein can regulate energy metabolism in healthy cells.
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Affiliation(s)
- Sara Sameni
- CNL, Salk Institute, La Jolla, California, UNITED STATES
| | - Run Zhang
- Surgery, University of California San Francisco, San Francisco, California, UNITED STATES
| | - Michelle A Digman
- Biomedical Engineering, University of California Irvine, University of California, Irvine, CA, United States, Irvine, California, UNITED STATES
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Banerjee P, Mondal D, Ghosh M, Mukherjee D, Nandi PK, Maiti TK, Sarkar N. Selective Self-Assembly of 5-Fluorouracil through Nonlinear Solvent Response Modulates Membrane Dynamics. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:2707-2719. [PMID: 32097563 DOI: 10.1021/acs.langmuir.9b03544] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Controllable self-assembly and understanding of the interaction between single metabolite fibrils and live-cell membranes have paramount importance in providing minimal treatment in several neurodegenerative disorders. Here, utilizing the nonlinear nature and peculiar hydrogen bonding behavior of the dimethyl sulfoxide (DMSO)-water mixture, the selective self-assembly of a single metabolite 5-fluorouracil (5-FU) is achieved. A direct correlation between water availability and selective self-assembly of 5-FU is ratified from the excited-state dynamics. The specific fibrillar structures of 5-FU exhibit a great potential to modulate live cell membrane fluidity and model membrane lipid distribution. After 5-FU fibril addition, a disorder of H-bonded water molecules arises several layers beyond the first hydration shell of the polar headgroups, which essentially modifies interfacial water structure and dynamics. Overall, our results shed light on the role of solvent to govern specific self-assembly and also lay the foundation accounting for the earlier stage of several diseases and multidrug resistance.
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Affiliation(s)
- Pavel Banerjee
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, West Bengal, India
| | - Dipankar Mondal
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, West Bengal, India
| | - Meghna Ghosh
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, West Bengal, India
| | - Devdeep Mukherjee
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur 721302, West Bengal, India
| | - Pratyush Kiran Nandi
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, West Bengal, India
| | - Tapas Kumar Maiti
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur 721302, West Bengal, India
| | - Nilmoni Sarkar
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, West Bengal, India
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White CM, Haidekker MA, Kisaalita WS. Ratiometric Nanoviscometers: Applications for Measuring Cellular Physical Properties in 3D Cultures. SLAS Technol 2020; 25:234-246. [PMID: 31997709 DOI: 10.1177/2472630319901262] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
New insights into the biomechanical properties of cells are revealing the importance of these properties and how they relate to underlying molecular, architectural, and behavioral changes associated with cell state and disease processes. However, the current understanding of how these in vitro biomechanical properties are associated with in vivo processes has been developed based on the traditional monolayer (two-dimensional [2D]) cell culture, which traditionally has not translated well to the three-dimensional (3D) cell culture and in vivo function. Many gold standard methods and tools used to observe the biomechanical properties of 2D cell cultures cannot be used with 3D cell cultures. Fluorescent molecules can respond to external factors almost instantaneously and require relatively low-cost instrumentation. In this review, we provide the background on fluorescent molecular rotors, which are attractive tools due to the relationship of their emission quantum yield with environmental microviscosity. We make the case for their use in both 2D and 3D cell cultures and speculate on their fundamental and practical applications in cell biology.
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Affiliation(s)
- Charles McRae White
- School of Chemical, Materials and Biomedical Engineering, College of Engineering, Driftmier Engineering Center, University of Georgia, Athens, GA, USA
| | - Mark A Haidekker
- School of Electrical and Computer Engineering, College of Engineering, Driftmier Engineering Center, University of Georgia, Athens, GA, USA
| | - William S Kisaalita
- School of Chemical, Materials and Biomedical Engineering, College of Engineering, Driftmier Engineering Center, University of Georgia, Athens, GA, USA
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28
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Sameni S, Zhang R, Digman MA. Number and molecular brightness analysis reveals Htt25Q protein aggregation upon the uptake of Htt97Q aggregates. Biochem Biophys Res Commun 2019; 522:133-137. [PMID: 31757420 DOI: 10.1016/j.bbrc.2019.10.041] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Accepted: 10/03/2019] [Indexed: 10/25/2022]
Abstract
Number and molecular Brightness (N&B) analysis is a powerful method used to monitor protein aggregation in living cells. Here, we used the N&B method to characterize the unexpanded HTT protein oligomerization after the internalization of the mutant HTT (mHTT) which contains a CAG repeat extensions encoding for long polyglutamine (polyQ) proteins resulting in misfolding and aggregation. HEK cells expressing Htt25Q-mCherry proteins were infected with Htt97Q-EGFP aggregates, by cell to cell uptake, in cultured conditions resulting in an increasing population of dimers and tetramers compared to our controls. This study shows for the first time the impact of protein aggregation in the unexpanded Htt25Q-mCherry expressing cells that occurs from cell to cell transfer of the expanded Htt97Q-EGFP. These results signify the sporadic behavior of the polyQ inclusion that gives insight into the mechanism of protein dynamics as a consequence of secreted mHTT aggregates.
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Affiliation(s)
- Sara Sameni
- Laboratory for Fluorescence Dynamics, USA; Department of Biomedical Engineering, USA
| | - Run Zhang
- Laboratory for Fluorescence Dynamics, USA; Department of Biomedical Engineering, USA
| | - Michelle A Digman
- Laboratory for Fluorescence Dynamics, USA; Department of Biomedical Engineering, USA; Department of Developmental and Cell Biology, USA; Department of Chemical Engineering and Material Sciences, University of California, Irvine, USA.
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29
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Conrard L, Tyteca D. Regulation of Membrane Calcium Transport Proteins by the Surrounding Lipid Environment. Biomolecules 2019; 9:E513. [PMID: 31547139 PMCID: PMC6843150 DOI: 10.3390/biom9100513] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 09/09/2019] [Accepted: 09/10/2019] [Indexed: 12/11/2022] Open
Abstract
Calcium ions (Ca2+) are major messengers in cell signaling, impacting nearly every aspect of cellular life. Those signals are generated within a wide spatial and temporal range through a large variety of Ca2+ channels, pumps, and exchangers. More and more evidences suggest that Ca2+ exchanges are regulated by their surrounding lipid environment. In this review, we point out the technical challenges that are currently being overcome and those that still need to be defeated to analyze the Ca2+ transport protein-lipid interactions. We then provide evidences for the modulation of Ca2+ transport proteins by lipids, including cholesterol, acidic phospholipids, sphingolipids, and their metabolites. We also integrate documented mechanisms involved in the regulation of Ca2+ transport proteins by the lipid environment. Those include: (i) Direct interaction inside the protein with non-annular lipids; (ii) close interaction with the first shell of annular lipids; (iii) regulation of membrane biophysical properties (e.g., membrane lipid packing, thickness, and curvature) directly around the protein through annular lipids; and (iv) gathering and downstream signaling of several proteins inside lipid domains. We finally discuss recent reports supporting the related alteration of Ca2+ and lipids in different pathophysiological events and the possibility to target lipids in Ca2+-related diseases.
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Affiliation(s)
- Louise Conrard
- CELL Unit, de Duve Institute and Université catholique de Louvain, UCL B1.75.05, avenue Hippocrate, 75, B-1200 Brussels, Belgium
| | - Donatienne Tyteca
- CELL Unit, de Duve Institute and Université catholique de Louvain, UCL B1.75.05, avenue Hippocrate, 75, B-1200 Brussels, Belgium.
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30
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Mishra M, Adhyapak P, Dadhich R, Kapoor S. Dynamic Remodeling of the Host Cell Membrane by Virulent Mycobacterial Sulfoglycolipid-1. Sci Rep 2019; 9:12844. [PMID: 31492926 PMCID: PMC6731295 DOI: 10.1038/s41598-019-49343-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 08/23/2019] [Indexed: 12/31/2022] Open
Abstract
Lipids dictate membrane properties to modulate lateral membrane organization, lipid/protein diffusion and lipid-protein interactions, thereby underpinning proper functioning of cells. Mycobacterium tuberculosis harnesses the power of its atypical cell wall lipids to impact immune surveillance machinery centered at the host cell membrane. However, the role of specific virulent lipids in altering host cellular functions by modulating membrane organization and the associated signaling response are still pertinent unresolved questions. Here, combining membrane biophysics and cell biology, we elucidate how virulent Mtb sulfoglycolipids hijack the host cell membrane, affecting its order, fluidity, and stiffness along with manipulating the linked cytoskeleton. The functional outcome of this perturbation was assayed by monitoring membrane-associated autophagy signaling. These actions form a part of the overall response to commandeer host membrane-associated immune processes during infection. The findings on the mechanism of action of Mtb lipids on host cell membrane structure and downstream signaling will deepen the collective understanding of their functional aspects in membrane-dictated bacterial survival, pathogenesis and drug resistance and reveal suitable membrane driven-therapeutic intervention points and diagnostic tools.
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Affiliation(s)
- Manjari Mishra
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, India
| | - Pranav Adhyapak
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, India
| | - Ruchika Dadhich
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, India
| | - Shobhna Kapoor
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, India.
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31
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Tao M, Pandey NK, Barnes R, Han S, Langen R. Structure of Membrane-Bound Huntingtin Exon 1 Reveals Membrane Interaction and Aggregation Mechanisms. Structure 2019; 27:1570-1580.e4. [PMID: 31466833 DOI: 10.1016/j.str.2019.08.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 07/23/2019] [Accepted: 08/09/2019] [Indexed: 02/08/2023]
Abstract
Huntington's disease is caused by a polyQ expansion in the first exon of huntingtin (Httex1). Membrane interaction of huntingtin is of physiological and pathological relevance. Using electron paramagnetic resonance and Overhauser dynamic nuclear polarization, we find that the N-terminal residues 3-13 of wild-type Httex1(Q25) form a membrane-bound, amphipathic α helix. This helix is positioned in the interfacial region, where it is sensitive to membrane curvature and electrostatic interactions with head-group charges. Residues 14-22, which contain the first five residues of the polyQ region, are in a transition region that remains in the interfacial region without taking up a stable, α-helical structure. The remaining C-terminal portion is solvent exposed. The phosphomimetic S13D/S16D mutations, which are known to protect from toxicity, inhibit membrane binding and attenuate membrane-mediated aggregation of mutant Httex1(Q46) due to electrostatic repulsion. Targeting the N-terminal membrane anchor using post-translational modifications or specific binders could be a potential means to reduce aggregation and toxicity in vivo.
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Affiliation(s)
- Meixin Tao
- Department of Neuroscience and Physiology, Department of Biochemistry and Molecular Medicine, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Nitin K Pandey
- Department of Neuroscience and Physiology, Department of Biochemistry and Molecular Medicine, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Ryan Barnes
- Department of Chemistry and Biochemistry, Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, CA 93106, USA
| | - Songi Han
- Department of Chemistry and Biochemistry, Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, CA 93106, USA
| | - Ralf Langen
- Department of Neuroscience and Physiology, Department of Biochemistry and Molecular Medicine, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA.
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32
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Dvornikov A, Malacrida L, Gratton E. The DIVER Microscope for Imaging in Scattering Media. Methods Protoc 2019; 2:E53. [PMID: 31234383 PMCID: PMC6632175 DOI: 10.3390/mps2020053] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2019] [Revised: 06/06/2019] [Accepted: 06/19/2019] [Indexed: 01/31/2023] Open
Abstract
We describe an advanced DIVER (Deep Imaging Via Emission Recovery) detection system for two-photon fluorescence microscopy that allows imaging in multiple scattering media, including biological tissues, up to a depth of a few mm with micron resolution. This detection system is more sensitive to low level light signals than conventional epi-detection used in two-photon fluorescence microscopes. The DIVER detector efficiently collects scattered emission photons from a wide area of turbid samples at almost any entrance angle in a 2π spherical angle. Using an epi-detection scheme only photons coming from a relatively small area of a sample and at narrow acceptance angle can be detected. The transmission geometry of the DIVER imaging system makes it exceptionally suitable for Second and Third Harmonic Generation (SHG, THG) signal detection. It also has in-depth fluorescence lifetime imaging (FLIM) capability. Using special optical filters with sin-cos spectral response, hyperspectral analysis of images acquired in-depth in scattering media can be performed. The system was successfully employed in imaging of various biological tissues. The DIVER detector can be plugged into a standard microscope stage and used as an external detector with upright commercial two-photon microscopes.
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Affiliation(s)
- Alexander Dvornikov
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California Irvine, Irvine, CA 92697, USA.
| | - Leonel Malacrida
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California Irvine, Irvine, CA 92697, USA.
- Departamento de Fisiopatología, Hospital de Clínicas, Facultad de Medicina, Universidad de la República-Uruguay, Montevideo 11400, Uruguay.
| | - Enrico Gratton
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California Irvine, Irvine, CA 92697, USA.
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33
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Liposomes as models for membrane integrity. Biochem Soc Trans 2019; 47:919-932. [PMID: 31085615 DOI: 10.1042/bst20190123] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 04/18/2019] [Accepted: 04/23/2019] [Indexed: 12/23/2022]
Abstract
Biological membranes form the boundaries to cells. They are integral to cellular function, retaining the valuable components inside and preventing access of unwanted molecules. Many different classes of molecules demonstrate disruptive properties to the plasma membrane. These include alcohols, detergents and antimicrobial agents. Understanding this disruption and the mechanisms by which it can be mitigated is vital for improved therapeutics as well as enhanced industrial processes where the compounds produced can be toxic to the membrane. This mini-review describes the most common molecules that disrupt cell membranes along with a range of in vitro liposome-based techniques that can be used to monitor and delineate these disruptive processes.
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Chen SJ, Sinsuebphon N, Rudkouskaya A, Barroso M, Intes X, Michalet X. In vitro and in vivo phasor analysis of stoichiometry and pharmacokinetics using short-lifetime near-infrared dyes and time-gated imaging. JOURNAL OF BIOPHOTONICS 2019; 12:e201800185. [PMID: 30421551 PMCID: PMC6559731 DOI: 10.1002/jbio.201800185] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 10/08/2018] [Accepted: 11/11/2018] [Indexed: 05/22/2023]
Abstract
We introduce a simple new approach for time-resolved multiplexed analysis of complex systems using near-infrared (NIR) dyes, applicable to in vitro and in vivo studies. We show that fast and precise in vitro quantification of NIR fluorophores' short (subnanosecond) lifetime and stoichiometry can be done using phasor analysis, a computationally efficient and user-friendly representation of complex fluorescence intensity decays obtained with pulsed laser excitation and time-gated camera imaging. We apply this approach to the study of binding equilibria by Förster resonant energy transfer using two different model systems: primary/secondary antibody binding in vitro and ligand/receptor binding in cell cultures. We then extend it to dynamic imaging of the pharmacokinetics of transferrin engagement with the transferrin receptor in live mice, elucidating the kinetics of differential transferrin accumulation in specific organs, straightforwardly differentiating specific from nonspecific binding. Our method, implemented in a freely-available software, has the advantage of time-resolved NIR imaging, including better tissue penetration and background-free imaging, but simplifies and considerably speeds up data processing and interpretation, while remaining quantitative. These advances make this method attractive and of broad applicability for in vitro and in vivo molecular imaging and could be extended to applications as diverse as image-guided surgery or optical tomography.
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Affiliation(s)
- Sez-Jade Chen
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, New York
| | - Nattawut Sinsuebphon
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, New York
| | - Alena Rudkouskaya
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, New York
| | - Margarida Barroso
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, New York
| | - Xavier Intes
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, New York
| | - Xavier Michalet
- Department of Chemistry and Biochemistry, University of California at Los Angeles, Los Angeles, California
- Correspondence Xavier Michalet, Department of Chemistry and Biochemistry, University of California at Los Angeles, Los Angeles, CA 90095.
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35
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Ranjit S, Malacrida L, Gratton E. Differences between FLIM phasor analyses for data collected with the Becker and Hickl SPC830 card and with the FLIMbox card. Microsc Res Tech 2018; 81:980-989. [PMID: 30295346 PMCID: PMC6240382 DOI: 10.1002/jemt.23061] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 05/13/2018] [Indexed: 01/31/2023]
Abstract
The phasor approach to FLIM (Fluorescence Lifetime Imaging Microscopy) is becoming popular due to the powerful fit free analysis and the visualization of the decay at each point in images of cells and tissues. However, although several implementation of the method are offered by manufactures of FLIM accessories for microscopes, the details of the conversion of the decay to phasors at each point in an image requires some consideration. Here, we show that if the decay is not properly acquired, the apparently simple phasor transformation can provide incorrect phasor plots and the results may be misinterpreted. In particular, we show the disagreement in experimental data acquired on the same samples using the two cards (FLIMbox, frequency domain and Becker & Hickl BH 830, time domain) and the effect produced by using the BH 830 card with different settings. This difference in data acquisition translates to the assignment of phasor components calculated using different acquisition parameters. This effect is already present in the original data that are not acquired with the proper parameters for the phasor conversion. We also show that the difference in the resolution of components already exists in the data acquired in the time domain when used with settings that do not allow acquisition of the fluorescence decay on a sufficient large time scale. RESEARCH HIGHLIGHTS: This paper is intended to made researchers aware of some simple requirements for the conversion of time-domain data (typically TCSPC) to phasors. The use of phasors for FLIM analysis has seen a surge of popularity. Since the phasor approach is a fit free method and has a powerful visualization of the data, it appears very simple to use. This paper shows that when the original data in the time domain is not acquired with the proper time range to cover the lifetimes in a sample, the conversion to phasors can produce very erroneous results. These results are appearing more frequently in the literature since many of the manufacturers of FLIM accessories for microscopes are now offering the phasor analysis in their software. Here, we show that the phasor transformation per se cannot correct for the problems with data acquisition and that one is misled to think that the "phasor approach" is a universal fix for the lack of the proper time range for data acquisition.
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Affiliation(s)
- Suman Ranjit
- Laboratory for Fluorescence Dynamics, University of California, Irvine, Irvine, California
| | - Leonel Malacrida
- Laboratory for Fluorescence Dynamics, University of California, Irvine, Irvine, California
- Departamento de Fisiopatología, Hospital de Clínicas, Universidad de la República, Montevideo, Uruguay
| | - Enrico Gratton
- Laboratory for Fluorescence Dynamics, University of California, Irvine, Irvine, California
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Philipsen MH, Phan NTN, Fletcher JS, Malmberg P, Ewing AG. Mass Spectrometry Imaging Shows Cocaine and Methylphenidate Have Opposite Effects on Major Lipids in Drosophila Brain. ACS Chem Neurosci 2018; 9:1462-1468. [PMID: 29508991 DOI: 10.1021/acschemneuro.8b00046] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used to study the effects of cocaine versus methylphenidate administration on both the localization and abundance of lipids in Drosophila melanogaster brain. A J105 ToF-SIMS with a 40 keV gas cluster primary ion source enabled us to probe molecular ions of biomolecules on the fly with a spatial resolution of ∼3 μm, giving us unique insights into the effect of these drugs on molecular lipids in the nervous system. Significant changes in phospholipid composition were observed in the central brain for both. Principal components image analysis revealed that changes occurred mainly for phosphatidylcholines, phosphatidylethanolamines, and phosphatidylinositols. When the lipid changes caused by cocaine were compared with those induced by methylphenidate, it was shown that these drugs exert opposite effects on the brain lipid structure. We speculate that this might relate to the molecular mechanism of cognition and memory.
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Affiliation(s)
- Mai H. Philipsen
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Gothenburg 412 96, Sweden
- Go:IMS, Chalmers University of Technology and University of Gothenburg, Gothenburg 412 96, Sweden
| | - Nhu T. N. Phan
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg 412 96, Sweden
- Go:IMS, Chalmers University of Technology and University of Gothenburg, Gothenburg 412 96, Sweden
- Institute of Neuro- and Sensory Physiology, Goettingen University Medical Center, Goettingen 37073, Germany
| | - John S. Fletcher
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg 412 96, Sweden
- Go:IMS, Chalmers University of Technology and University of Gothenburg, Gothenburg 412 96, Sweden
| | - Per Malmberg
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Gothenburg 412 96, Sweden
- Go:IMS, Chalmers University of Technology and University of Gothenburg, Gothenburg 412 96, Sweden
| | - Andrew G. Ewing
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Gothenburg 412 96, Sweden
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg 412 96, Sweden
- Go:IMS, Chalmers University of Technology and University of Gothenburg, Gothenburg 412 96, Sweden
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