1
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Skeens A, Markle JM, Petipas G, Frey SL, Legleiter J. Divalent cations promote huntingtin fibril formation on endoplasmic reticulum derived and model membranes. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2024; 1866:184339. [PMID: 38763270 DOI: 10.1016/j.bbamem.2024.184339] [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: 09/13/2023] [Revised: 04/24/2024] [Accepted: 05/12/2024] [Indexed: 05/21/2024]
Abstract
Huntington's Disease (HD) is caused by an abnormal expansion of the polyglutamine (polyQ) domain within the first exon of the huntingtin protein (htt). This expansion promotes disease-related htt aggregation into amyloid fibrils and the formation of proteinaceous inclusion bodies within neurons. Fibril formation is a complex heterogenous process involving an array of aggregate species such as oligomers, protofibrils, and fibrils. In HD, structural abnormalities of membranes of several organelles develop. In particular, the accumulation of htt fibrils near the endoplasmic reticulum (ER) impinges upon the membrane, resulting in ER damage, altered dynamics, and leakage of Ca2+. Here, the aggregation of htt at a bilayer interface assembled from ER-derived liposomes was investigated, and fibril formation directly on these membranes was enhanced. Based on these observations, simplified model systems were used to investigate mechanisms associated with htt aggregation on ER membranes. As the ER-derived liposome fractions contained residual Ca2+, the role of divalent cations was also investigated. In the absence of lipids, divalent cations had minimal impact on htt structure and aggregation. However, the presence of Ca2+ or Mg2+ played a key role in promoting fibril formation on lipid membranes despite reduced htt insertion into and association with lipid interfaces, suggesting that the ability of divalent cations to promote fibril formation on membranes is mediated by induced changes to the lipid membrane physicochemical properties. With enhanced concentrations of intracellular calcium being a hallmark of HD, the ability of divalent cations to influence htt aggregation at lipid membranes may play a role in aggregation events that lead to organelle abnormalities associated with disease.
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Affiliation(s)
- Adam Skeens
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, USA
| | - Jordyn M Markle
- The Department of Chemistry, Gettysburg College, 300 N. Washington Street, Gettysburg, PA 17325, USA
| | - Gabriella Petipas
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, USA
| | - Shelli L Frey
- The Department of Chemistry, Gettysburg College, 300 N. Washington Street, Gettysburg, PA 17325, USA.
| | - Justin Legleiter
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, USA; Rockefeller Neurosciences Institutes, West Virginia University, 1 Medical Center Dr., P.O. Box 9303, Morgantown, WV 26505, USA; Department of Neuroscience, West Virginia University, 1 Medical Center Dr., P.O. Box 9303, Morgantown, WV 26505, USA.
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2
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Zhang Z, Gehin C, Abriata LA, Dal Peraro M, Lashuel H. Differential Effects of Post-translational Modifications on the Membrane Interaction of Huntingtin Protein. ACS Chem Neurosci 2024. [PMID: 38752226 DOI: 10.1021/acschemneuro.4c00091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2024] Open
Abstract
Huntington's disease is a neurodegenerative disorder caused by an expanded polyglutamine stretch near the N-terminus of the huntingtin (HTT) protein, rendering the protein more prone to aggregate. The first 17 residues in HTT (Nt17) interact with lipid membranes and harbor multiple post-translational modifications (PTMs) that can modulate HTT conformation and aggregation. In this study, we used a combination of biophysical studies and molecular simulations to investigate the effect of PTMs on the helicity of Nt17 in the presence of various lipid membranes. We demonstrate that anionic lipids such as PI4P, PI(4,5)P2, and GM1 significantly enhance the helical structure of unmodified Nt17. This effect is attenuated by single acetylation events at K6, K9, or K15, whereas tri-acetylation at these sites abolishes Nt17-membrane interaction. Similarly, single phosphorylation at S13 and S16 decreased but did not abolish the POPG and PIP2-induced helicity, while dual phosphorylation at these sites markedly diminished Nt17 helicity, regardless of lipid composition. The helicity of Nt17 with phosphorylation at T3 is insensitive to the membrane environment. Oxidation at M8 variably affects membrane-induced helicity, highlighting a lipid-dependent modulation of the Nt17 structure. Altogether, our findings reveal differential effects of PTMs and crosstalks between PTMs on membrane interaction and conformation of HTT. Intriguingly, the effects of phosphorylation at T3 or single acetylation at K6, K9, and K15 on Nt17 conformation in the presence of certain membranes do not mirror that observed in the absence of membranes. Our studies provide novel insights into the complex relationship between Nt17 structure, PTMs, and membrane binding.
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Affiliation(s)
- Zhidian Zhang
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, School of Life Sciences, Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland
- Laboratory for Biomolecular Modeling, School of Life Sciences, Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland
| | - Charlotte Gehin
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, School of Life Sciences, Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland
| | - Luciano A Abriata
- Laboratory for Biomolecular Modeling, School of Life Sciences, Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland
| | - Matteo Dal Peraro
- Laboratory for Biomolecular Modeling, School of Life Sciences, Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland
| | - Hilal Lashuel
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, School of Life Sciences, Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland
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3
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Skeens A, Siriwardhana C, Massinople SE, Wunder MM, Ellis ZL, Keith KM, Girman T, Frey SL, Legleiter J. The polyglutamine domain is the primary driver of seeding in huntingtin aggregation. PLoS One 2024; 19:e0298323. [PMID: 38483973 PMCID: PMC10939245 DOI: 10.1371/journal.pone.0298323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 01/22/2024] [Indexed: 03/17/2024] Open
Abstract
Huntington's Disease (HD) is a fatal, neurodegenerative disease caused by aggregation of the huntingtin protein (htt) with an expanded polyglutamine (polyQ) domain into amyloid fibrils. Htt aggregation is modified by flanking sequences surrounding the polyQ domain as well as the binding of htt to lipid membranes. Upon fibrillization, htt fibrils are able to template the aggregation of monomers into fibrils in a phenomenon known as seeding, and this process appears to play a critical role in cell-to-cell spread of HD. Here, exposure of C. elegans expressing a nonpathogenic N-terminal htt fragment (15-repeat glutamine residues) to preformed htt-exon1 fibrils induced inclusion formation and resulted in decreased viability in a dose dependent manner, demonstrating that seeding can induce toxic aggregation of nonpathogenic forms of htt. To better understand this seeding process, the impact of flanking sequences adjacent to the polyQ stretch, polyQ length, and the presence of model lipid membranes on htt seeding was investigated. Htt seeding readily occurred across polyQ lengths and was independent of flanking sequence, suggesting that the structured polyQ domain within fibrils is the key contributor to the seeding phenomenon. However, the addition of lipid vesicles modified seeding efficiency in a manner suggesting that seeding primarily occurs in bulk solution and not at the membrane interface. In addition, fibrils formed in the presence of lipid membranes displayed similar seeding efficiencies. Collectively, this suggests that the polyQ domain that forms the amyloid fibril core is the main driver of seeding in htt aggregation.
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Affiliation(s)
- Adam Skeens
- The C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia, United States of America
| | - Chathuranga Siriwardhana
- The C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia, United States of America
| | - Sophia E. Massinople
- The C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia, United States of America
| | - Michelle M. Wunder
- The C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia, United States of America
| | - Zachary L. Ellis
- The C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia, United States of America
| | - Kaitlyn M. Keith
- The C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia, United States of America
| | - Tyler Girman
- The C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia, United States of America
| | - Shelli L. Frey
- The Department of Chemistry, Gettysburg College, Gettysburg, Pennsylvania, United States of America
| | - Justin Legleiter
- The C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia, United States of America
- Rockefeller Neurosciences Institutes, West Virginia University, Morgantown, West Virginia, United States of America
- Department of Neuroscience, West Virginia University, Morgantown, West Virginia, United States of America
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4
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Dinamarca MC, Colombo L, Brykczynska U, Grimm A, Fruh I, Hossain I, Gabriel D, Eckert A, Müller M, Pecho-Vrieseling E. Transmission-selective muscle pathology induced by the active propagation of mutant huntingtin across the human neuromuscular synapse. Front Mol Neurosci 2024; 16:1287510. [PMID: 38235149 PMCID: PMC10791992 DOI: 10.3389/fnmol.2023.1287510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 11/27/2023] [Indexed: 01/19/2024] Open
Abstract
Neuron-to-neuron transmission of aggregation-prone, misfolded proteins may potentially explain the spatiotemporal accumulation of pathological lesions in the brains of patients with neurodegenerative protein-misfolding diseases (PMDs). However, little is known about protein transmission from the central nervous system to the periphery, or how this propagation contributes to PMD pathology. To deepen our understanding of these processes, we established two functional neuromuscular systems derived from human iPSCs. One was suitable for long-term high-throughput live-cell imaging and the other was adapted to a microfluidic system assuring that connectivity between motor neurons and muscle cells was restricted to the neuromuscular junction. We show that the Huntington's disease (HD)-associated mutant HTT exon 1 protein (mHTTEx1) is transmitted from neurons to muscle cells across the human neuromuscular junction. We found that transmission is an active and dynamic process that starts before aggregate formation and is regulated by synaptic activity. We further found that transmitted mHTTEx1 causes HD-relevant pathology at both molecular and functional levels in human muscle cells, even in the presence of the ubiquitous expression of mHTTEx1. In conclusion, we have uncovered a causal link between mHTTEx1 synaptic transmission and HD pathology, highlighting the therapeutic potential of blocking toxic protein transmission in PMDs.
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Affiliation(s)
- Margarita C. Dinamarca
- Neuronal Development and Degeneration Laboratory, Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Laura Colombo
- Neuronal Development and Degeneration Laboratory, Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Urszula Brykczynska
- Neuronal Development and Degeneration Laboratory, Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Amandine Grimm
- Neurobiology Laboratory for Brain Aging and Mental Health, Transfaculty Research Platform, Molecular and Cognitive Neuroscience, University of Basel, Basel, Switzerland
| | - Isabelle Fruh
- Biomedical Research, Novartis Pharma AG, Novartis Campus, Basel, Switzerland
| | - Imtiaz Hossain
- Biomedical Research, Novartis Pharma AG, Novartis Campus, Basel, Switzerland
| | - Daniela Gabriel
- Biomedical Research, Novartis Pharma AG, Novartis Campus, Basel, Switzerland
| | - Anne Eckert
- Neurobiology Laboratory for Brain Aging and Mental Health, Transfaculty Research Platform, Molecular and Cognitive Neuroscience, University of Basel, Basel, Switzerland
| | - Matthias Müller
- Biomedical Research, Novartis Pharma AG, Novartis Campus, Basel, Switzerland
| | - Eline Pecho-Vrieseling
- Neuronal Development and Degeneration Laboratory, Department of Biomedicine, University of Basel, Basel, Switzerland
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5
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Gamage YI, Pan J. Elucidating the Influence of Lipid Composition on Bilayer Perturbations Induced by the N-terminal Region of the Huntingtin Protein. BIOPHYSICA 2023; 3:582-597. [PMID: 38737720 PMCID: PMC11087071 DOI: 10.3390/biophysica3040040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2024]
Abstract
Understanding the membrane interactions of the N-terminal 17 residues of the huntingtin protein (HttN) is essential for unraveling its role in cellular processes and its impact on huntingtin misfolding. In this study, we used atomic force microscopy (AFM) to examine the effects of lipid specificity in mediating bilayer perturbations induced by HttN. Across various lipid environments, the peptide consistently induced bilayer disruptions in the form of holes. Notably, our results unveiled that cholesterol enhanced bilayer perturbation induced by HttN, while phosphatidylethanolamine (PE) lipids suppressed hole formation. Furthermore, anionic phosphatidylglycerol (PG) and cardiolipin lipids, along with cholesterol at high concentrations, promoted the formation of double-bilayer patches. This unique structure suggests that the synergy among HttN, anionic lipids, and cholesterol can enhance bilayer fusion, potentially by facilitating lipid intermixing between adjacent bilayers. Additionally, our AFM-based force spectroscopy revealed that HttN enhanced the mechanical stability of lipid bilayers, as evidenced by an elevated bilayer puncture force. These findings illuminate the complex interplay between HttN and lipid membranes and provide useful insights into the role of lipid composition in modulating membrane interactions with the huntingtin protein.
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Affiliation(s)
| | - Jianjun Pan
- Department of Physics, University of South Florida, Tampa, FL 33620
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6
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Burtscher J, Pepe G, Maharjan N, Riguet N, Di Pardo A, Maglione V, Millet GP. Sphingolipids and impaired hypoxic stress responses in Huntington disease. Prog Lipid Res 2023; 90:101224. [PMID: 36898481 DOI: 10.1016/j.plipres.2023.101224] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 02/20/2023] [Accepted: 03/05/2023] [Indexed: 03/11/2023]
Abstract
Huntington disease (HD) is a debilitating, currently incurable disease. Protein aggregation and metabolic deficits are pathological hallmarks but their link to neurodegeneration and symptoms remains debated. Here, we summarize alterations in the levels of different sphingolipids in an attempt to characterize sphingolipid patterns specific to HD, an additional molecular hallmark of the disease. Based on the crucial role of sphingolipids in maintaining cellular homeostasis, the dynamic regulation of sphingolipids upon insults and their involvement in cellular stress responses, we hypothesize that maladaptations or blunted adaptations, especially following cellular stress due to reduced oxygen supply (hypoxia) contribute to the development of pathology in HD. We review how sphingolipids shape cellular energy metabolism and control proteostasis and suggest how these functions may fail in HD and in combination with additional insults. Finally, we evaluate the potential of improving cellular resilience in HD by conditioning approaches (improving the efficiency of cellular stress responses) and the role of sphingolipids therein. Sphingolipid metabolism is crucial for cellular homeostasis and for adaptations following cellular stress, including hypoxia. Inadequate cellular management of hypoxic stress likely contributes to HD progression, and sphingolipids are potential mediators. Targeting sphingolipids and the hypoxic stress response are novel treatment strategies for HD.
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Affiliation(s)
- Johannes Burtscher
- Institute of Sport Sciences, University of Lausanne, 1015 Lausanne, Switzerland; Department of Biomedical Sciences, University of Lausanne, 1005 Lausanne, Switzerland.
| | - Giuseppe Pepe
- IRCCS Neuromed, Via Dell'Elettronica, 86077 Pozzilli, Italy
| | - Niran Maharjan
- Department of Neurology, Center for Experimental Neurology, Inselspital University Hospital, 3010 Bern, Switzerland; Department for Biomedical Research (DBMR), University of Bern, 3010 Bern, Switzerland
| | | | - Alba Di Pardo
- IRCCS Neuromed, Via Dell'Elettronica, 86077 Pozzilli, Italy
| | | | - Grégoire P Millet
- Institute of Sport Sciences, University of Lausanne, 1015 Lausanne, Switzerland; Department of Biomedical Sciences, University of Lausanne, 1005 Lausanne, Switzerland
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7
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Ramos-Martín F, D'Amelio N. Biomembrane lipids: When physics and chemistry join to shape biological activity. Biochimie 2022; 203:118-138. [PMID: 35926681 DOI: 10.1016/j.biochi.2022.07.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 07/13/2022] [Accepted: 07/21/2022] [Indexed: 11/02/2022]
Abstract
Biomembranes constitute the first lines of defense of cells. While small molecules can often permeate cell walls in bacteria and plants, they are generally unable to penetrate the barrier constituted by the double layer of phospholipids, unless specific receptors or channels are present. Antimicrobial or cell-penetrating peptides are in fact highly specialized molecules able to bypass this barrier and even discriminate among different cell types. This capacity is made possible by the intrinsic properties of its phospholipids, their distribution between the internal and external leaflet, and their ability to mutually interact, modulating the membrane fluidity and the exposition of key headgroups. Although common phospholipids can be found in the membranes of most organisms, some are characteristic of specific cell types. Here, we review the properties of the most common lipids and describe how they interact with each other in biomembrane. We then discuss how their assembly in bilayers determines some key physical-chemical properties such as permeability, potential and phase status. Finally, we describe how the exposition of specific phospholipids determines the recognition of cell types by membrane-targeting molecules.
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Affiliation(s)
- Francisco Ramos-Martín
- Unité de Génie Enzymatique et Cellulaire UMR 7025 CNRS, Université de Picardie Jules Verne, Amiens, 80039, France.
| | - Nicola D'Amelio
- Unité de Génie Enzymatique et Cellulaire UMR 7025 CNRS, Université de Picardie Jules Verne, Amiens, 80039, France.
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8
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Adegbuyiro A, Stonebraker AR, Sedighi F, Fan CK, Hodges B, Li P, Valentine SJ, Legleiter J. Oxidation Promotes Distinct Huntingtin Aggregates in the Presence and Absence of Membranes. Biochemistry 2022; 61:1517-1530. [PMID: 35759798 DOI: 10.1021/acs.biochem.2c00212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Expansion of a polyglutamine (polyQ) domain within the first exon of the huntingtin (htt) protein is the underlying cause of Huntington's disease, a genetic neurodegenerative disorder. PolyQ expansion triggers htt aggregation into oligomers, fibrils, and inclusions. The 17 N-terminal amino acids (Nt17) of htt-exon1, which directly precede the polyQ domain enhances polyQ fibrillization and functions as a lipid-binding domain. A variety of post-translational modifications occur within Nt17, including oxidation of two methionine residues. Here, the impact of oxidation within Nt17 on htt aggregation both in the presence and absence of lipid membranes was investigated. Treatment with hydrogen peroxide (H2O2) reduced fibril formation in a dose-dependent manner, resulting in shorter fibrils and an increased oligomer population. With excessive H2O2 treatments, fibrils developed a unique morphological feature around their periphery. In the presence of total brain lipid vesicles, H2O2 impacted fibrillization in a similar manner. That is, oligomerization was promoted at the expense of fibril elongation. The interaction of unoxidized and oxidized htt with supported lipid bilayers was directly observed using in situ atomic force microscopy. Without oxidation, granular htt aggregates developed on the bilayer surface. However, in the presence of H2O2, distinct plateau-like regions initially developed on the bilayer surface that gave way to rougher patches containing granular aggregates. Collectively, these observations suggest that oxidation of methionine residues within Nt17 plays a crucial role in both the aggregation of htt and its ability to interact with lipid surfaces.
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Affiliation(s)
- Adewale Adegbuyiro
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Alyssa R Stonebraker
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Faezeh Sedighi
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Caleb K Fan
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Breanna Hodges
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Peng Li
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Stephen J Valentine
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Justin Legleiter
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States.,Rockefeller Neurosciences Institutes, West Virginia University, 1 Medical Center Dr., P.O. Box 9303, Morgantown, West Virginia 26505, United States.,Department of Neuroscience, West Virginia University, 1 Medical Center Dr., P.O. Box 9303, Morgantown, West Virginia 26505, United States
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9
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Beasley M, Frazee N, Groover S, Valentine SJ, Mertz B, Legleiter J. Physicochemical Properties Altered by the Tail Group of Lipid Membranes Influence Huntingtin Aggregation and Lipid Binding. J Phys Chem B 2022; 126:3067-3081. [PMID: 35439000 DOI: 10.1021/acs.jpcb.1c10254] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Huntington's disease is a neurodegenerative disorder caused by an expanded polyglutamine (polyQ) domain within the huntingtin protein (htt) that initiates toxic protein aggregation. Htt directly interacts with membranes, influencing aggregation and spurring membrane abnormalities. These interactions are facilitated by the 17 N-terminal residues (Nt17) that form an amphipathic α-helix implicated in both lipid binding and aggregation. Here, the impact of unsaturation in phospholipid tails on htt-lipid interaction and htt aggregation was determined. There was no correlation between the degree of htt-lipid complexation and the degree of htt aggregation in the presence of each lipid system, indicating that lipid systems with different properties uniquely alter the membrane-mediated aggregation mechanisms. Also, the association between Nt17 and membrane surfaces is determined by complementarity between hydrophobic residues and membrane defects and how easily the peptide can partition into the bilayer. Our results provide critical insights into how membrane physical properties influence downstream htt aggregation.
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Affiliation(s)
- Maryssa Beasley
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Nicolas Frazee
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Sharon Groover
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Stephen J Valentine
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Blake Mertz
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States.,WVU Cancer Institute, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Justin Legleiter
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States.,Blanchette Rockefeller Neurosciences Institutes, West Virginia University, 1 Medical Center Drive, P.O. Box 9303, Morgantown, West Virginia 26505, United States.,Department of Neuroscience, West Virginia University, 1 Medical Center Drive, P.O. Box 9303, Morgantown, West Virginia 26505, United States
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10
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Kacher R, Mounier C, Caboche J, Betuing S. Altered Cholesterol Homeostasis in Huntington’s Disease. Front Aging Neurosci 2022; 14:797220. [PMID: 35517051 PMCID: PMC9063567 DOI: 10.3389/fnagi.2022.797220] [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: 10/18/2021] [Accepted: 03/18/2022] [Indexed: 12/25/2022] Open
Abstract
Huntington’s disease (HD) is an autosomal dominant genetic disorder caused by an expansion of the CAG repeat in the first exon of Huntingtin’s gene. The associated neurodegeneration mainly affects the striatum and the cortex at early stages and progressively spreads to other brain structures. Targeting HD at its earlier stages is under intense investigation. Numerous drugs were tested, with a rate of success of only 3.5% approved molecules used as symptomatic treatment. The restoration of cholesterol metabolism, which is central to the brain homeostasis and strongly altered in HD, could be an interesting disease-modifying strategy. Cholesterol is an essential membrane component in the central nervous system (CNS); alterations of its homeostasis have deleterious consequences on neuronal functions. The levels of several sterols, upstream of cholesterol, are markedly decreased within the striatum of HD mouse model. Transcription of cholesterol biosynthetic genes is reduced in HD cell and mouse models as well as post-mortem striatal and cortical tissues from HD patients. Since the dynamic of brain cholesterol metabolism is complex, it is essential to establish the best method to target it in HD. Cholesterol, which does not cross the blood-brain-barrier, is locally synthesized and renewed within the brain. All cell types in the CNS synthesize cholesterol during development but as they progress through adulthood, neurons down-regulate their cholesterol synthesis and turn to astrocytes for their full supply. Cellular levels of cholesterol reflect the dynamic balance between synthesis, uptake and export, all integrated into the context of the cross talk between neurons and glial cells. In this review, we describe the latest advances regarding the role of cholesterol deregulation in neuronal functions and how this could be a determinant factor in neuronal degeneration and HD progression. The pathways and major mechanisms by which cholesterol and sterols are regulated in the CNS will be described. From this overview, we discuss the main clinical strategies for manipulating cholesterol metabolism in the CNS, and how to reinstate a proper balance in HD.
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Affiliation(s)
- Radhia Kacher
- Institut du Cerveau - Paris Brain Institute (ICM), AP-HP, INSERM, CNRS, University Hospital Pitié-Salpêtrière, Sorbonne Université, Paris, France
- INSERM, U1216, Grenoble Institut Neurosciences, Université Grenoble Alpes, Grenoble, France
| | - Coline Mounier
- Neuroscience Paris Seine, Institut de Biologie Paris-Seine, Faculté des Sciences et Ingénierie, Sorbonne Université, Paris, France
- Centre National de la Recherche Scientifique, UMR 8246, Paris, France
- U1130, Institut National de la Santé et de la Recherche Médicale, Paris, France
| | - Jocelyne Caboche
- Neuroscience Paris Seine, Institut de Biologie Paris-Seine, Faculté des Sciences et Ingénierie, Sorbonne Université, Paris, France
- Centre National de la Recherche Scientifique, UMR 8246, Paris, France
- U1130, Institut National de la Santé et de la Recherche Médicale, Paris, France
| | - Sandrine Betuing
- Neuroscience Paris Seine, Institut de Biologie Paris-Seine, Faculté des Sciences et Ingénierie, Sorbonne Université, Paris, France
- Centre National de la Recherche Scientifique, UMR 8246, Paris, France
- U1130, Institut National de la Santé et de la Recherche Médicale, Paris, France
- *Correspondence: Sandrine Betuing,
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11
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Adegbuyiro A, Sedighi F, Jain P, Pinti MV, Siriwardhana C, Hollander JM, Legleiter J. Mitochondrial membranes modify mutant huntingtin aggregation. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2021; 1863:183663. [PMID: 34089719 PMCID: PMC8328955 DOI: 10.1016/j.bbamem.2021.183663] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 05/17/2021] [Accepted: 05/28/2021] [Indexed: 02/08/2023]
Abstract
Huntington's disease (HD) is a neurodegenerative disease caused by the expansion of a polyglutamine (polyQ) tract near the N-terminus of the huntingtin (htt) protein. Expanded polyQ tracts are prone to aggregate into oligomers and insoluble fibrils. Mutant htt (mhtt) localizes to variety of organelles, including mitochondria. Specifically, mitochondrial defects, morphological alteration, and dysfunction are observed in HD. Mitochondrial lipids, cardiolipin (CL) in particular, are essential in mitochondria function and have the potential to directly interact with htt, altering its aggregation. Here, the impact of mitochondrial membranes on htt aggregation was investigated using a combination of mitochondrial membrane mimics and tissue-derived mitochondrial-enriched fractions. The impact of exposure of outer and inner mitochondrial membrane mimics (OMM and IMM respectively) to mhtt was explored. OMM and IMM reduced mhtt fibrillization, with IMM having a larger effect. The role of CL in mhtt aggregation was investigated using a simple PC system with varying molar ratios of CL. Lower molar ratios of CL (<5%) promoted fibrillization; however, increased CL content retarded fibrillization. As revealed by in situ AFM, mhtt aggregation and associated membrane morphological changes at the surface of OMM mimics was markedly different compared to IMM mimics. While globular deposits of mhtt with few fibrillar aggregates were observed on OMM, plateau-like domains were observed on IMM. A similar impact on htt aggregation was observed with exposure to purified mitochondrial-enriched fractions. Collectively, these observations suggest mitochondrial membranes heavily influence htt aggregation with implication for HD.
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Affiliation(s)
- Adewale Adegbuyiro
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, United States
| | - Faezeh Sedighi
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, United States
| | - Pranav Jain
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, United States
| | - Mark V Pinti
- Division of Exercise Physiology, West Virginia School of Medicine, Morgantown, WV 26506, United States; Mitochondria, Metabolism & Bioenergetics Working Group, West Virginia University School of Medicine, Morgantown, WV, USA
| | - Chathuranga Siriwardhana
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, United States
| | - John M Hollander
- Division of Exercise Physiology, West Virginia School of Medicine, Morgantown, WV 26506, United States; Mitochondria, Metabolism & Bioenergetics Working Group, West Virginia University School of Medicine, Morgantown, WV, USA
| | - Justin Legleiter
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, United States; Rockefeller Neurosciences Institutes, West Virginia University, 1 Medical Center Dr., P.O. Box 9303, Morgantown, WV 26505, United States; Department of Neuroscience, West Virginia University, 1 Medical Center Dr., P.O. Box 9303, Morgantown, WV 26505, United States.
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12
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Groover SE, Adegbuyiro A, Fan CK, Hodges BL, Beasley M, Taylor K, Stonebraker AR, Siriwardhana C, Legleiter J. Macromolecular crowding in solution alters huntingtin interaction and aggregation at interfaces. Colloids Surf B Biointerfaces 2021; 206:111969. [PMID: 34246856 DOI: 10.1016/j.colsurfb.2021.111969] [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] [Received: 03/10/2021] [Revised: 06/16/2021] [Accepted: 07/05/2021] [Indexed: 10/20/2022]
Abstract
Huntington's disease (HD) is a fatal neurodegenerative disease caused by an extended polyglutamine (polyQ) domain within the first exon of the huntingtin protein (htt). PolyQ expansion directly invokes the formation of a heterogenous mixture of toxic htt aggregates, including fibrils and oligomers. While htt is a cytosolic protein, it also associates with numerous membranous surfaces within the cell, leading to altered organelle morphology and dysfunction. Here, the impact of macromolecular crowding on htt aggregation in bulk solution and at solid/liquid or membrane/liquid interfaces was investigated. Dextran, Ficoll, and polyethylene glycol (PEG) were used as crowding agents. In bulk solution, crowding enhanced the heterogeneity of non-fibrillar aggregate species formed in a crowder dependent manner. However, crowding agents interfered with the deposition of htt fibrils on mica, suggesting that a crowded aqueous phase influences the interaction of htt with interfaces. By use of in situ atomic force microcopy (AFM), the aggregation of htt directly at mica and bilayer interfaces was tracked. The predominate aggregates type observed to form at the mica interface was fibrillar, but oligomeric aggregates of various stabilities were also observed. Crowding in the aqueous phase suppressed deposition and formation of htt aggregates on mica. In contrast, the addition of crowders enhanced deposition of htt aggregates onto supported total brain lipid extract (TBLE) bilayers. Different crowding agents led to distinct htt aggregates on supported bilayers with unique morphological impact on bilayer integrity. Collectively, these observations point to the complexity of htt aggregation at interfaces and that crowding in the aqueous phase profoundly influences this process.
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Affiliation(s)
- Sharon E Groover
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, United States
| | - Adewale Adegbuyiro
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, United States
| | - Caleb K Fan
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, United States
| | - Breanna L Hodges
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, United States
| | - Maryssa Beasley
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, United States
| | - Katelyn Taylor
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, United States
| | - Alyssa R Stonebraker
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, United States
| | - Chathuranga Siriwardhana
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, United States
| | - Justin Legleiter
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, United States; Rockefeller Neurosciences Institutes, West Virginia University, 1 Medical Center Dr., P.O. Box 9303, Morgantown, WV 26505, United States; Department of Neuroscience, West Virginia University, 1 Medical Center Dr., P.O. Box 9303, Morgantown, WV 26505, United States.
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13
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Zhang N, Bewick B, Schultz J, Tiwari A, Krencik R, Zhang A, Adachi K, Xia G, Yun K, Sarkar P, Ashizawa T. DNAzyme Cleavage of CAG Repeat RNA in Polyglutamine Diseases. Neurotherapeutics 2021; 18:1710-1728. [PMID: 34160773 PMCID: PMC8609077 DOI: 10.1007/s13311-021-01075-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/11/2021] [Indexed: 02/05/2023] Open
Abstract
CAG repeat expansion is the genetic cause of nine incurable polyglutamine (polyQ) diseases with neurodegenerative features. Silencing repeat RNA holds great therapeutic value. Here, we developed a repeat-based RNA-cleaving DNAzyme that catalyzes the destruction of expanded CAG repeat RNA of six polyQ diseases with high potency. DNAzyme preferentially cleaved the expanded allele in spinocerebellar ataxia type 1 (SCA1) cells. While cleavage was non-allele-specific for spinocerebellar ataxia type 3 (SCA3) cells, treatment of DNAzyme leads to improved cell viability without affecting mitochondrial metabolism or p62-dependent aggresome formation. DNAzyme appears to be stable in mouse brain for at least 1 month, and an intermediate dosage of DNAzyme in a SCA3 mouse model leads to a significant reduction of high molecular weight ATXN3 proteins. Our data suggest that DNAzyme is an effective RNA silencing molecule for potential treatment of multiple polyQ diseases.
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Affiliation(s)
- Nan Zhang
- Department of Neurology, Neuroscience Program, Houston Methodist Research Institute, Houston, TX USA
| | - Brittani Bewick
- Department of Neurology, Neuroscience Program, Houston Methodist Research Institute, Houston, TX USA
| | - Jason Schultz
- Department of Neurology, Neuroscience Program, Houston Methodist Research Institute, Houston, TX USA
| | - Anjana Tiwari
- Department of Neurology, Neuroscience Program, Houston Methodist Research Institute, Houston, TX USA
| | - Robert Krencik
- Center for Neuroregeneration, Department of Neurosurgery, Houston Methodist Research Institute, Houston, TX USA
| | - Aijun Zhang
- Center for Bioenergetics, Department of Neurosurgery, Houston Methodist Research Institute, Houston, TX USA
| | - Kaho Adachi
- Department of Molecular and Cell Biology, UC-Berkeley, Berkeley, CA USA
| | - Guangbin Xia
- Indiana University School of Medicine-Fort Wayne, Fort Wayne, IN USA
| | - Kyuson Yun
- Department of Neurology, Neuroscience Program, Houston Methodist Research Institute, Houston, TX USA
| | - Partha Sarkar
- Department of Neurology and Department of Neuroscience, Cell Biology and Anatomy, UTMB Health, Galveston, TX USA
| | - Tetsuo Ashizawa
- Department of Neurology, Neuroscience Program, Houston Methodist Research Institute, Houston, TX USA
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14
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Marquette A, Aisenbrey C, Bechinger B. Membrane Interactions Accelerate the Self-Aggregation of Huntingtin Exon 1 Fragments in a Polyglutamine Length-Dependent Manner. Int J Mol Sci 2021; 22:ijms22136725. [PMID: 34201610 PMCID: PMC8268948 DOI: 10.3390/ijms22136725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 06/07/2021] [Accepted: 06/18/2021] [Indexed: 12/04/2022] Open
Abstract
The accumulation of aggregated protein is a typical hallmark of many human neurodegenerative disorders, including polyglutamine-related diseases such as chorea Huntington. Misfolding of the amyloidogenic proteins gives rise to self-assembled complexes and fibres. The huntingtin protein is characterised by a segment of consecutive glutamines which, when exceeding ~ 37 residues, results in the occurrence of the disease. Furthermore, it has also been demonstrated that the 17-residue amino-terminal domain of the protein (htt17), located upstream of this polyglutamine tract, strongly correlates with aggregate formation and pathology. Here, we demonstrate that membrane interactions strongly accelerate the oligomerisation and β-amyloid fibril formation of htt17-polyglutamine segments. By using a combination of biophysical approaches, the kinetics of fibre formation is investigated and found to be strongly dependent on the presence of lipids, the length of the polyQ expansion, and the polypeptide-to-lipid ratio. Finally, the implications for therapeutic approaches are discussed.
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Affiliation(s)
- Arnaud Marquette
- Chemistry Institute UMR7177, University of Strasbourg/CNRS, 67000 Strasbourg, France; (A.M.); (C.A.)
| | - Christopher Aisenbrey
- Chemistry Institute UMR7177, University of Strasbourg/CNRS, 67000 Strasbourg, France; (A.M.); (C.A.)
| | - Burkhard Bechinger
- Chemistry Institute UMR7177, University of Strasbourg/CNRS, 67000 Strasbourg, France; (A.M.); (C.A.)
- Insitut Universitaire de France, 75005 Paris, France
- Correspondence:
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15
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Groover SE, Beasley M, Ramamurthy V, Legleiter J. Phosphomimetic Mutations Impact Huntingtin Aggregation in the Presence of a Variety of Lipid Systems. Biochemistry 2020; 59:4681-4693. [PMID: 33256402 DOI: 10.1021/acs.biochem.0c00788] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Huntington's disease (HD) is a neurodegenerative disorder caused by the abnormal expansion of a polyglutamine (polyQ) tract in the first exon of the htt protein (htt). PolyQ expansion triggers the aggregation of htt into a variety of structures, including oligomers and fibrils. This aggregation is impacted by the first 17 N-terminal amino acids (Nt17) of htt that directly precedes the polyQ domain. Beyond impacting aggregation, Nt17 associates with lipid membranes by forming an amphipathic α-helix. Post-translational modifications within Nt17 are known to modify HD pathology, and in particular, phosphorylation at T3, S13, and/or S16 retards fibrillization and ameliorates the phenotype in HD models. Due to Nt17's propensity to interact with lipid membranes, the impact of introducing phosphomimetic mutations (T3D, S13D, and S16D) into htt-exon1 on aggregation in the presence of a variety of model lipid membranes (total brain lipid extract, 1-palmitoyl-2-oleoyl-glycero-3-phosphatidylcholine, and 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-1'-rac-glycerol) was investigated. Phosphomimetic mutations altered htt's interaction with and aggregation in the presence of lipids; however, this was dependent on the lipid system.
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Affiliation(s)
- Sharon E Groover
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Maryssa Beasley
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Visvanathan Ramamurthy
- Department of Ophthalmology, West Virginia University, Morgantown, West Virginia 26506, United States.,Department of Biochemistry, West Virginia University, Morgantown, West Virginia 26506, United States.,Rockefeller Neurosciences Institutes, West Virginia University, 1 Medical Center Drive, P.O. Box 9303, Morgantown, West Virginia 26505, United States
| | - Justin Legleiter
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States.,Rockefeller Neurosciences Institutes, West Virginia University, 1 Medical Center Drive, P.O. Box 9303, Morgantown, West Virginia 26505, United States.,Department of Neuroscience, West Virginia University, 1 Medical Center Drive, P.O. Box 9303, Morgantown, West Virginia 26505, United States
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16
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Normalizing polydiacetylene colorimetric assays of vesicle binding across lipid systems. Anal Biochem 2020; 609:113864. [DOI: 10.1016/j.ab.2020.113864] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 06/24/2020] [Accepted: 07/07/2020] [Indexed: 11/18/2022]
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17
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Lipid headgroups alter huntingtin aggregation on membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1863:183497. [PMID: 33130095 DOI: 10.1016/j.bbamem.2020.183497] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 10/09/2020] [Accepted: 10/12/2020] [Indexed: 12/13/2022]
Abstract
Huntington's Disease is a fatal neurodegenerative disorder caused by expansion of a glutamine repeat region (polyQ) beyond a critical threshold within exon1 of the huntingtin protein (htt). As a consequence of polyQ expansion, htt associates into a variety of aggregate species that are thought to underlie cellular toxicity. Within cells, htt associates with numerous membranous organelles and surfaces that exert influence on the aggregation process. In particular, the first 17 amino acids at the N-terminus of htt (Nt17) serve as a lipid-binding domain that is intrinsically disordered in bulk solution but adopts an amphipathic α-helical structure upon binding membranes. Beyond this, Nt17 is implicated in initiating htt fibrillization. As the interaction between Nt17 and lipid membranes is likely influenced by lipid properties, the impact of lipid headgroups on htt-exon1 aggregation, membrane activity, and the ability to form protein:lipid complexes was determined. Htt-exon1 with a disease-length polyQ domain (46Q) was exposed to lipid vesicles comprised of lipids with either zwitterionic (POPC and POPE) or anionic (POPG and POPS) headgroups. With zwitterionic head groups, large lipid to peptide ratios were required to have a statistically significant impact on htt aggregation. Anionic lipids enhanced htt fibrillization, even at low lipid:protein ratios, and this was accompanied by changes in aggregate morphology. Despite the larger impact of anionic lipids, htt-exon1(46Q) was more membrane active with zwitterionic lipid systems. The ability of Nt17 to form complexes with lipids was also mediated by lipid headgroups as zwitterionic ionic lipids more readily associated with multimeric forms of Nt17 in comparison with anionic lipids. Collectively, these results highlight the complexity of htt/membrane interactions and the resulting impact on the aggregation process.
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18
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Loss of Hap1 selectively promotes striatal degeneration in Huntington disease mice. Proc Natl Acad Sci U S A 2020; 117:20265-20273. [PMID: 32747555 DOI: 10.1073/pnas.2002283117] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Huntington disease (HD) is an ideal model for investigating selective neurodegeneration, as expanded polyQ repeats in the ubiquitously expressed huntingtin (HTT) cause the preferential neurodegeneration in the striatum of the HD patient brains. Here we report that adeno-associated virus (AAV) transduction-mediated depletion of Hap1, the first identified huntingtin-associated protein, in adult HD knock-in (KI) mouse brains leads to selective neuronal loss in the striatum. Further, Hap1 depletion-mediated neuronal loss via AAV transduction requires the presence of mutant HTT. Rhes, a GTPase that is enriched in the striatum and sumoylates mutant HTT to mediate neurotoxicity, binds more N-terminal HTT when Hap1 is deficient. Consistently, more soluble and sumoylated N-terminal HTT is presented in HD KI mouse striatum when HAP1 is absent. Our findings suggest that both Rhes and Hap1 as well as cellular stress contribute to the preferential neurodegeneration in HD, highlighting the involvement of multiple factors in selective neurodegeneration.
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19
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Sedighi F, Adegbuyiro A, Legleiter J. SUMOylation Prevents Huntingtin Fibrillization and Localization onto Lipid Membranes. ACS Chem Neurosci 2020; 11:328-343. [PMID: 31880908 DOI: 10.1021/acschemneuro.9b00509] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Huntington's disease (HD), a genetic neurodegenerative disease, is caused by an expanded polyglutamine (polyQ) domain in the first exon of the huntingtin protein (htt). PolyQ expansion destabilizes protein structure, resulting in aggregation into a variety of oligomers, protofibrils, and fibrils. Beyond the polyQ domain, adjacent protein sequences influence the aggregation process. Specifically, the first 17 N-terminal amino acids (Nt17) directly preceding the polyQ domain promote the formation of α-helix-rich oligomers that represent intermediate species associated with fibrillization. Due to its propensity to form an amphipathic α-helix, Nt17 also facilitates lipid binding. Three lysine residues (K6, K9, and K15) within Nt17 can be SUMOylated, which modifies htt's accumulation and toxicity within cells in a variety of HD models. The impact of SUMOylation on htt aggregation and direct interaction with lipid membranes was investigated. SUMOylation of htt-exon1 inhibited fibril formation while promoting larger, amorphous aggregate species. These amorphous aggregates were SDS soluble but nonetheless exhibited levels of β-sheet structure similar to that of htt-exon1 fibrils. In addition, SUMOylation prevented htt binding, aggregation, and accumulation on model lipid bilayers comprised of total brain lipid extract. Collectively, these observations demonstrate that SUMOylation promotes a distinct htt aggregation pathway that may affect htt toxicity.
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Affiliation(s)
- Faezeh Sedighi
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Adewale Adegbuyiro
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Justin Legleiter
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
- Rockefeller Neurosciences Institutes, West Virginia University, 1 Medical Center Drive, P.O. Box 9303, Morgantown, West Virginia 26505, United States
- Department of Neuroscience, West Virginia University, 1 Medical Center Drive, P.O. Box 9303, Morgantown, West Virginia 26505, United States
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20
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Karanji AK, Beasely M, Sharif D, Ranjbaran A, Legleiter J, Valentine SJ. Investigating the interactions of the first 17 amino acid residues of Huntingtin with lipid vesicles using mass spectrometry and molecular dynamics. JOURNAL OF MASS SPECTROMETRY : JMS 2020; 55:e4470. [PMID: 31756784 PMCID: PMC7342490 DOI: 10.1002/jms.4470] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 10/04/2019] [Accepted: 10/28/2019] [Indexed: 06/10/2023]
Abstract
The first 17 amino acid residues of Huntingtin protein (Nt17 of htt) are thought to play an important role in the protein's function; Nt17 is one of two membrane binding domains in htt. In this study the binding ability of Nt17 peptide with vesicles comprised of two subclasses of phospholipids is studied using electrospray ionization - mass spectrometry (ESI-MS) and molecular dynamics (MD) simulations. Overall, the peptide is shown to have a greater propensity to interact with vesicles of phosphatidylcholine (PC) rather than phosphatidylethanolamine (PE) lipids. Mass spectra show an increase in lipid-bound peptide adducts where the ordering of the number of such specie is 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) > 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine (POPC) > 1-palmitoyl-2-oleoyl-sn-glycero-3 phosphoethanolamine (POPE). MD simulations suggest that the compactness of the bilayer plays a role in governing peptide interactions. The peptide shows greater disruption of the DOPC bilayer order at the surface and interacts with the hydrophobic tails of lipid molecules via hydrophobic residues. Conversely, the POPE vesicle remains ordered and lipids display transient interactions with the peptide through the formation of hydrogen bonds with hydrophilic residues. The POPC system displays intermediate behavior with regard to the degree of peptide-membrane interaction. Finally, the simulations suggest a helix stabilizing effect resulting from the interactions between hydrophobic residues and the lipid tails of the DOPC bilayer.
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Affiliation(s)
- Ahmad Kiani Karanji
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown WV 26506
| | - Maryssa Beasely
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown WV 26506
| | - Daud Sharif
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown WV 26506
| | - Ali Ranjbaran
- Department of Microbiology, Immunology, and Cell Biology, West Virginia University School of Medicine, Morgantown WV 26506
| | - Justin Legleiter
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown WV 26506
- Blanchette Rockefeller Neurosciences Institute, Robert C. Byrd Health Sciences Center, P.O. Box 9304, West Virginia University, Morgantown, West Virginia 26506, United States
- NanoSAFE, P.O. Box 6223, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Stephen J. Valentine
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown WV 26506
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21
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Beasley M, Stonebraker AR, Hasan I, Kapp KL, Liang BJ, Agarwal G, Groover S, Sedighi F, Legleiter J. Lipid Membranes Influence the Ability of Small Molecules To Inhibit Huntingtin Fibrillization. Biochemistry 2019; 58:4361-4373. [PMID: 31608620 DOI: 10.1021/acs.biochem.9b00739] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Several diseases, including Alzheimer's disease, Parkinson's disease, and Huntington's disease (HD), are associated with specific proteins aggregating and depositing within tissues and/or cellular compartments. The aggregation of these proteins is characterized by the formation of extended, β-sheet rich fibrils, termed amyloid. In addition, a variety of other aggregate species also form, including oligomers and protofibrils. Specifically, HD is caused by the aggregation of the huntingtin (htt) protein that contains an expanded polyglutamine domain. Due to the link between protein aggregation and disease, small molecule aggregation inhibitors have been pursued as potential therapeutic agents. Two such small molecules are epigallocatechin 3-gallate (EGCG) and curcumin, both of which inhibit the fibril formation of several amyloid-forming proteins. However, amyloid formation is a complex process that is strongly influenced by the protein's environment, leading to distinct aggregation pathways. Thus, changes in the protein's environment may alter the effectiveness of aggregation inhibitors. A well-known modulator of amyloid formation is lipid membranes. Here, we investigated if the presence of lipid vesicles altered the ability of EGCG or curcumin to modulate htt aggregation and influence the interaction of htt with lipid membranes. The presence of 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine or total brain lipid extract vesicles prevented the curcumin from inhibiting htt fibril formation. In contrast, EGCG's inhibition of htt fibril formation persisted in the presence of lipids. Collectively, these results highlight the complexity of htt aggregation and demonstrate that the presence of lipid membranes is a key modifier of the ability of small molecules to inhibit htt fibril formation.
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Affiliation(s)
- Maryssa Beasley
- The C. Eugene Bennett Department of Chemistry , West Virginia University , 217 Clark Hall , Morgantown , West Virginia 26506 , United States
| | - Alyssa R Stonebraker
- The C. Eugene Bennett Department of Chemistry , West Virginia University , 217 Clark Hall , Morgantown , West Virginia 26506 , United States
| | - Iraj Hasan
- The C. Eugene Bennett Department of Chemistry , West Virginia University , 217 Clark Hall , Morgantown , West Virginia 26506 , United States
| | - Kathryn L Kapp
- The C. Eugene Bennett Department of Chemistry , West Virginia University , 217 Clark Hall , Morgantown , West Virginia 26506 , United States
| | - Barry J Liang
- The C. Eugene Bennett Department of Chemistry , West Virginia University , 217 Clark Hall , Morgantown , West Virginia 26506 , United States
| | - Garima Agarwal
- The C. Eugene Bennett Department of Chemistry , West Virginia University , 217 Clark Hall , Morgantown , West Virginia 26506 , United States
| | - Sharon Groover
- The C. Eugene Bennett Department of Chemistry , West Virginia University , 217 Clark Hall , Morgantown , West Virginia 26506 , United States
| | - Faezeh Sedighi
- The C. Eugene Bennett Department of Chemistry , West Virginia University , 217 Clark Hall , Morgantown , West Virginia 26506 , United States
| | - Justin Legleiter
- The C. Eugene Bennett Department of Chemistry , West Virginia University , 217 Clark Hall , Morgantown , West Virginia 26506 , United States.,Rockefeller Neurosciences Institute , West Virginia University , 1 Medical Center Drive , P.O. Box 9303, Morgantown , West Virginia 26505 , United States.,Department of Neuroscience , West Virginia University , 1 Medical Center Drive , P.O. Box 9303, Morgantown , West Virginia 26505 , United States
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22
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Ceccon A, Clore GM, Tugarinov V. Decorrelating Kinetic and Relaxation Parameters in Exchange Saturation Transfer NMR: A Case Study of N-Terminal Huntingtin Peptides Binding to Unilamellar Lipid Vesicles. J Phys Chem B 2018; 122:11271-11278. [PMID: 30156416 DOI: 10.1021/acs.jpcb.8b07112] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Dark state exchange saturation transfer (DEST) and lifetime line-broadening (Δ R2, the difference in the measured transverse relaxation rates for the observable species in the presence and absence of exchange with a species characterized by very large intrinsic transverse relaxation rates) have proven to be powerful NMR tools for studying exchange phenomena between a NMR visible species and a high-molecular weight, "dark", NMR invisible state. However, in the exchange regime, where the transverse spin relaxation rates in the bound state ( R2bound) are smaller than the strength of the DEST saturation radio frequency field, typically corresponding to systems below ∼6 MDa, the combination of DEST and Δ R2 data, while sufficient to define the apparent association rate constant, cannot unambiguously determine the population of the bound state pB and R2bound values independently. We show that the latter exchange and relaxation parameters can be decorrelated by the measurement of the maximal value of the contribution of the fast-relaxing magnetization component to the total NMR signal, Cfastmax, an observable that is directly proportional to pB. When integrated into the analysis of DEST/Δ R2 data, Cfastmax provides an indispensable source of information for quantitative studies of exchange involving high-molecular-weight dark states. We demonstrate the utility of this approach by investigating the binding kinetics of two huntingtin exon-1-derived peptides to small unilamellar lipid vesicles (SUV), ∼ 31 nm in diameter and 4.3 MDa in molecular weight. The interaction of the N-terminal amphiphilic domain of huntingtin exon-1 with membrane surfaces promotes polyglutamine-mediated aggregation and, as such, is thought to play a role in the etiology of Huntington's disease, an autosomal dominant fatal neurodegenerative condition. The first peptide comprises the 16-residue N-terminal amphiphilic domain (httNT) alone, while the second contains an additional seven residue polyglutamine tract at the C-terminus (httNTQ7). At a peptide-to-lipid molar ratio of 1:4, the population of peptide bound to the SUV surface is substantial, ∼ 7-8%, while exchange between the free and SUV-bound peptide is slow on the relaxation time-scale ( kex ∼ 200 s-1). The last two C-terminal residues of httNT and the last 9 of httNTQ7 remain flexible in the SUV-bound form due to transient detachment from the lipid surface that occurs on a time-scale several-fold faster than binding.
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Affiliation(s)
- Alberto Ceccon
- Laboratory of Chemical Physics , National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health , Bethesda , Maryland 20892-0520 , United States
| | - G Marius Clore
- Laboratory of Chemical Physics , National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health , Bethesda , Maryland 20892-0520 , United States
| | - Vitali Tugarinov
- Laboratory of Chemical Physics , National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health , Bethesda , Maryland 20892-0520 , United States
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23
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Ceccon A, Schmidt T, Tugarinov V, Kotler SA, Schwieters CD, Clore GM. Interaction of Huntingtin Exon-1 Peptides with Lipid-Based Micellar Nanoparticles Probed by Solution NMR and Q-Band Pulsed EPR. J Am Chem Soc 2018; 140:6199-6202. [PMID: 29727175 DOI: 10.1021/jacs.8b02619] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Lipid-based micellar nanoparticles promote aggregation of huntingtin exon-1 peptides. Here we characterize the interaction of two such peptides, httNTQ 7 and httNTQ 10 comprising the N-terminal amphiphilic domain of huntingtin followed by 7 and 10 glutamine repeats, respectively, with 8 nm lipid micelles using NMR chemical exchange saturation transfer (CEST), circular dichroism and pulsed Q-band EPR. Exchange between free and micelle-bound httNTQ n peptides occurs on the millisecond time scale with a KD ∼ 0.5-1 mM. Upon binding micelles, residues 1-15 adopt a helical conformation. Oxidation of Met7 to a sulfoxide reduces the binding affinity for micelles ∼3-4-fold and increases the length of the helix by a further two residues. A structure of the bound monomer unit is calculated from the backbone chemical shifts of the micelle-bound state obtained from CEST. Pulsed Q-band EPR shows that a monomer-dimer equilibrium exists on the surface of the micelles and that the two helices of the dimer adopt a parallel orientation, thereby bringing two disordered polyQ tails into close proximity which may promote aggregation upon dissociation from the micelle surface.
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Affiliation(s)
- Alberto Ceccon
- Laboratory of Chemical Physics , National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health , Bethesda , Maryland 20892-520 , United States
| | - Thomas Schmidt
- Laboratory of Chemical Physics , National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health , Bethesda , Maryland 20892-520 , United States
| | - Vitali Tugarinov
- Laboratory of Chemical Physics , National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health , Bethesda , Maryland 20892-520 , United States
| | - Samuel A Kotler
- Laboratory of Chemical Physics , National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health , Bethesda , Maryland 20892-520 , United States
| | - Charles D Schwieters
- Imaging Sciences Laboratory , Center for Information Technology, National Institutes of Health , Bethesda , Maryland 20892-5624 , United States
| | - G Marius Clore
- Laboratory of Chemical Physics , National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health , Bethesda , Maryland 20892-520 , United States
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24
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Chaibva M, Gao X, Jain P, Campbell WA, Frey SL, Legleiter J. Sphingomyelin and GM1 Influence Huntingtin Binding to, Disruption of, and Aggregation on Lipid Membranes. ACS OMEGA 2018; 3:273-285. [PMID: 29399649 PMCID: PMC5793032 DOI: 10.1021/acsomega.7b01472] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 12/25/2017] [Indexed: 05/09/2023]
Abstract
Huntington disease (HD) is an inherited neurodegenerative disease caused by the expansion beyond a critical threshold of a polyglutamine (polyQ) tract near the N-terminus of the huntingtin (htt) protein. Expanded polyQ promotes the formation of a variety of oligomeric and fibrillar aggregates of htt that accumulate into the hallmark proteinaceous inclusion bodies associated with HD. htt is also highly associated with numerous cellular and subcellular membranes that contain a variety of lipids. As lipid homeostasis and metabolism abnormalities are observed in HD patients, we investigated how varying both the sphingomyelin (SM) and ganglioside (GM1) contents modifies the interactions between htt and lipid membranes. SM composition is altered in HD, and GM1 has been shown to have protective effects in animal models of HD. A combination of Langmuir trough monolayer techniques, vesicle permeability and binding assays, and in situ atomic force microscopy (AFM) were used to directly monitor the interaction of a model, synthetic htt peptide and a full-length htt-exon1 recombinant protein with model membranes comprised of total brain lipid extract (TBLE) and varying amounts of exogenously added SM or GM1. The addition of either SM or GM1 decreased htt insertion into the lipid monolayers. However, TBLE vesicles with an increased SM content were more susceptible to htt-induced permeabilization, whereas GM1 had no effect on permeablization. Pure TBLE bilayers and TBLE bilayers enriched with GM1 developed regions of roughened, granular morphologies upon exposure to htt-exon1, but plateau-like domains with a smoother appearance formed in bilayers enriched with SM. Oligomeric aggregates were observed on all bilayer systems regardless of induced morphology. Collectively, these observations suggest that the lipid composition and its subsequent effects on membrane material properties strongly influence htt binding and aggregation on lipid membranes.
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Affiliation(s)
- Maxmore Chaibva
- The
C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, P.O. Box 6045, Morgantown, West Virginia 26505, United States
| | - Xiang Gao
- The
C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, P.O. Box 6045, Morgantown, West Virginia 26505, United States
| | - Pranav Jain
- The
C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, P.O. Box 6045, Morgantown, West Virginia 26505, United States
| | - Warren A. Campbell
- Department
of Chemistry, Gettysburg College, 300 N. Washington Avenue, Campus Box 0393, Gettysburg, Pennsylvania 17325, United States
| | - Shelli L. Frey
- Department
of Chemistry, Gettysburg College, 300 N. Washington Avenue, Campus Box 0393, Gettysburg, Pennsylvania 17325, United States
- E-mail: . Phone: 717-337-6259 (S.L.F.)
| | - Justin Legleiter
- The
C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, P.O. Box 6045, Morgantown, West Virginia 26505, United States
- Blanchette
Rockefeller Neurosciences Institutes, West
Virginia University, 1 Medical Center Dr., P.O. Box 9303, Morgantown, West Virginia 26505, United States
- E-mail: . Phone: 304-293-0175 (J.L.)
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25
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Sameni S, Malacrida L, Tan Z, Digman MA. Alteration in Fluidity of Cell Plasma Membrane in Huntington Disease Revealed by Spectral Phasor Analysis. Sci Rep 2018; 8:734. [PMID: 29335600 PMCID: PMC5768877 DOI: 10.1038/s41598-018-19160-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 12/22/2017] [Indexed: 12/18/2022] Open
Abstract
Huntington disease (HD) is a late-onset genetic neurodegenerative disorder caused by expansion of cytosine-adenine-guanine (CAG) trinucleotide in the exon 1 of the gene encoding the polyglutamine (polyQ). It has been shown that protein degradation and lipid metabolism is altered in HD. In many neurodegenerative disorders, impaired lipid homeostasis is one of the early events in the disease onset. Yet, little is known about how mutant huntingtin may affect phospholipids membrane fluidity. Here, we investigated how membrane fluidity in the living cells (differentiated PC12 and HEK293 cell lines) are affected using a hyperspectral imaging of widely used probes, LAURDAN. Using phasor approach, we characterized the fluorescence of LAURDAN that is sensitive to the polarity of the immediate environment. LAURDAN is affected by the physical order of phospholipids (lipid order) and reports the membrane fluidity. We also validated our results using a different fluorescent membrane probe, Nile Red (NR). The plasma membrane in the cells expressing expanded polyQ shows a shift toward increased membrane fluidity revealed by both LAURDAN and NR spectral phasors. This finding brings a new perspective in the understanding of the early stages of HD that can be used as a target for drug screening.
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Affiliation(s)
- Sara Sameni
- Laboratory for Fluorescence Dynamics, University of California Irvine, Irvine, CA, USA
- Department of Biomedical Engineering, University of California Irvine, Irvine, CA, USA
| | - Leonel Malacrida
- Laboratory for Fluorescence Dynamics, University of California Irvine, Irvine, CA, USA
- Department of Biomedical Engineering, University of California Irvine, Irvine, CA, USA
- Departamento de Fisiopatología, Hospital de Clinicas, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Zhiqun Tan
- Institute for Memory Impairments and Neurological Disorders, University of California Irvine, Irvine, USA
| | - Michelle A Digman
- Laboratory for Fluorescence Dynamics, University of California Irvine, Irvine, CA, USA.
- Department of Biomedical Engineering, University of California Irvine, Irvine, CA, USA.
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26
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Arenas F, Garcia-Ruiz C, Fernandez-Checa JC. Intracellular Cholesterol Trafficking and Impact in Neurodegeneration. Front Mol Neurosci 2017; 10:382. [PMID: 29204109 PMCID: PMC5698305 DOI: 10.3389/fnmol.2017.00382] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 11/02/2017] [Indexed: 12/13/2022] Open
Abstract
Cholesterol is a critical component of membrane bilayers where it plays key structural and functional roles by regulating the activity of diverse signaling platforms and pathways. Particularly enriched in brain, cholesterol homeostasis in this organ is singular with respect to other tissues and exhibits a heterogeneous regulation in distinct brain cell populations. Due to the key role of cholesterol in brain physiology and function, alterations in cholesterol homeostasis and levels have been linked to brain diseases and neurodegeneration. In the case of Alzheimer disease (AD), however, this association remains unclear with evidence indicating that either increased or decreased total brain cholesterol levels contribute to this major neurodegenerative disease. Here, rather than analyzing the role of total cholesterol levels in neurodegeneration, we focus on the contribution of intracellular cholesterol pools, particularly in endolysosomes and mitochondria through its trafficking via specialized membrane domains delineated by the contacts between endoplasmic reticulum and mitochondria, in the onset of prevalent neurodegenerative diseases such as AD, Parkinson disease, and Huntington disease as well as in lysosomal disorders like Niemann-Pick type C disease. We dissect molecular events associated with intracellular cholesterol accumulation, especially in mitochondria, an event that results in impaired mitochondrial antioxidant defense and function. A better understanding of the mechanisms involved in the distribution of cholesterol in intracellular compartments may shed light on the role of cholesterol homeostasis disruption in neurodegeneration and may pave the way for specific intervention opportunities.
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Affiliation(s)
- Fabian Arenas
- Department of Cell Death and Proliferation, Instituto de Investigaciones Biomédicas de Barcelona, Consejo Superior de Investigaciones Científicas, Barcelona, Spain
- Liver Unit and Hospital Clinic I Provincial, IDIBAPS, Barcelona, Spain
- Centro de Investigación Biomédica en Red, CIBEREHD, Barcelona, Spain
| | - Carmen Garcia-Ruiz
- Department of Cell Death and Proliferation, Instituto de Investigaciones Biomédicas de Barcelona, Consejo Superior de Investigaciones Científicas, Barcelona, Spain
- Liver Unit and Hospital Clinic I Provincial, IDIBAPS, Barcelona, Spain
- Centro de Investigación Biomédica en Red, CIBEREHD, Barcelona, Spain
- Southern California Research Center for ALDP and Cirrhosis, Los Angeles, CA, United States
| | - Jose C. Fernandez-Checa
- Department of Cell Death and Proliferation, Instituto de Investigaciones Biomédicas de Barcelona, Consejo Superior de Investigaciones Científicas, Barcelona, Spain
- Liver Unit and Hospital Clinic I Provincial, IDIBAPS, Barcelona, Spain
- Centro de Investigación Biomédica en Red, CIBEREHD, Barcelona, Spain
- Southern California Research Center for ALDP and Cirrhosis, Los Angeles, CA, United States
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27
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Defective Sphingosine-1-phosphate metabolism is a druggable target in Huntington's disease. Sci Rep 2017; 7:5280. [PMID: 28706199 PMCID: PMC5509685 DOI: 10.1038/s41598-017-05709-y] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 06/01/2017] [Indexed: 12/22/2022] Open
Abstract
Huntington’s disease is characterized by a complex and heterogeneous pathogenic profile. Studies have shown that disturbance in lipid homeostasis may represent a critical determinant in the progression of several neurodegenerative disorders. The recognition of perturbed lipid metabolism is only recently becoming evident in HD. In order to provide more insight into the nature of such a perturbation and into the effect its modulation may have in HD pathology, we investigated the metabolism of Sphingosine-1-phosphate (S1P), one of the most important bioactive lipids, in both animal models and patient samples. Here, we demonstrated that S1P metabolism is significantly disrupted in HD even at early stage of the disease and importantly, we revealed that such a dysfunction represents a common denominator among multiple disease models ranging from cells to humans through mouse models. Interestingly, the in vitro anti-apoptotic and the pro-survival actions seen after modulation of S1P-metabolizing enzymes allows this axis to emerge as a new druggable target and unfolds its promising therapeutic potential for the development of more effective and targeted interventions against this incurable condition.
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28
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Fatty acid-based lipidomics and membrane remodeling induced by apoE3 and apoE4 in human neuroblastoma cells. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:1967-1973. [PMID: 28688796 DOI: 10.1016/j.bbamem.2017.07.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 06/19/2017] [Accepted: 07/04/2017] [Indexed: 02/08/2023]
Abstract
Apolipoprotein E (apoE) is a major lipid carrier of the lipoprotein transport system that plays critical roles in various pathologies. Human apoE has three common isoforms, the apoE4 being associated with Alzheimer's disease. This is the first study in the literature investigating the effects of apoE (apoE3 and apoE4 isoforms) on membrane fatty acid profile in neuroblastoma SK-N-SH cells. Fatty acid analyses were carried out by gas chromatography of the corresponding methyl esters (FAME). We observed the occurrence of membrane fatty acid remodeling in the presence of each of the two apoE isoforms. ApoE3 increased the membrane level of stearic acid and dihomo-gamma-linolenic acid (DGLA), whereas apoE4 had opposite effects. Both apoE3 and apoE4 increased saturated and monounsaturated fatty acids (SFA and MUFA), omega-6/omega-3 ratio and decreased total polyunsaturated fatty acid (PUFA) amount, but with various intensities. Moreover, both apoE isoforms decreased membrane homeostasis indexes such as PUFA balance, unsaturation index and peroxidation index. Our results highlight membrane property changes connected to the apoE isoforms suggesting membrane lipidomics to be inserted in further model studies of apolipoproteins in health and disease.
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29
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Jung J, Michalak M, Agellon LB. Endoplasmic Reticulum Malfunction in the Nervous System. Front Neurosci 2017; 11:220. [PMID: 28487627 PMCID: PMC5403925 DOI: 10.3389/fnins.2017.00220] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 03/31/2017] [Indexed: 12/12/2022] Open
Abstract
Neurodegenerative diseases often have multifactorial causes and are progressive diseases. Some are inherited while others are acquired, and both vary greatly in onset and severity. Impaired endoplasmic reticulum (ER) proteostasis, involving Ca2+ signaling, protein synthesis, processing, trafficking, and degradation, is now recognized as a key risk factor in the pathogenesis of neurological disorders. Lipidostasis involves lipid synthesis, quality control, membrane assembly as well as sequestration of excess lipids or degradation of damaged lipids. Proteostasis and lipidostasis are maintained by interconnected pathways within the cellular reticular network, which includes the ER and Ca2+ signaling. Importantly, lipidostasis is important in the maintenance of membranes and luminal environment that enable optimal protein processing. Accumulating evidence suggest that the loss of coordinate regulation of proteostasis and lipidostasis has a direct and negative impact on the health of the nervous system.
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Affiliation(s)
- Joanna Jung
- Department of Biochemistry, University of AlbertaEdmonton, AB, Canada
| | - Marek Michalak
- Department of Biochemistry, University of AlbertaEdmonton, AB, Canada
| | - Luis B Agellon
- School of Dietetics and Human Nutrition, McGill UniversitySte. Anne de Bellevue, QC, Canada
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30
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Adegbuyiro A, Sedighi F, Pilkington AW, Groover S, Legleiter J. Proteins Containing Expanded Polyglutamine Tracts and Neurodegenerative Disease. Biochemistry 2017; 56:1199-1217. [PMID: 28170216 DOI: 10.1021/acs.biochem.6b00936] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Several hereditary neurological and neuromuscular diseases are caused by an abnormal expansion of trinucleotide repeats. To date, there have been 10 of these trinucleotide repeat disorders associated with an expansion of the codon CAG encoding glutamine (Q). For these polyglutamine (polyQ) diseases, there is a critical threshold length of the CAG repeat required for disease, and further expansion beyond this threshold is correlated with age of onset and symptom severity. PolyQ expansion in the translated proteins promotes their self-assembly into a variety of oligomeric and fibrillar aggregate species that accumulate into the hallmark proteinaceous inclusion bodies associated with each disease. Here, we review aggregation mechanisms of proteins with expanded polyQ-tracts, structural consequences of expanded polyQ ranging from monomers to fibrillar aggregates, the impact of protein context and post-translational modifications on aggregation, and a potential role for lipid membranes in aggregation. As the pathogenic mechanisms that underlie these disorders are often classified as either a gain of toxic function or loss of normal protein function, some toxic mechanisms associated with mutant polyQ tracts will also be discussed.
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Affiliation(s)
- Adewale Adegbuyiro
- The C. Eugene Bennett Department of Chemistry, 217 Clark Hall, West Virginia University , Morgantown, West Virginia 26506, United States
| | - Faezeh Sedighi
- The C. Eugene Bennett Department of Chemistry, 217 Clark Hall, West Virginia University , Morgantown, West Virginia 26506, United States
| | - Albert W Pilkington
- The C. Eugene Bennett Department of Chemistry, 217 Clark Hall, West Virginia University , Morgantown, West Virginia 26506, United States
| | - Sharon Groover
- The C. Eugene Bennett Department of Chemistry, 217 Clark Hall, West Virginia University , Morgantown, West Virginia 26506, United States
| | - Justin Legleiter
- The C. Eugene Bennett Department of Chemistry, 217 Clark Hall, West Virginia University , Morgantown, West Virginia 26506, United States.,Blanchette Rockefeller Neurosciences Institute, Robert C. Byrd Health Sciences Center, P.O. Box 9304, West Virginia University , Morgantown, West Virginia 26506, United States.,NanoSAFE, P.O. Box 6223, West Virginia University , Morgantown, West Virginia 26506, United States
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31
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Aufschnaiter A, Kohler V, Diessl J, Peselj C, Carmona-Gutierrez D, Keller W, Büttner S. Mitochondrial lipids in neurodegeneration. Cell Tissue Res 2017; 367:125-140. [PMID: 27449929 PMCID: PMC5203858 DOI: 10.1007/s00441-016-2463-1] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2016] [Accepted: 06/24/2016] [Indexed: 01/10/2023]
Abstract
Mitochondrial dysfunction is a common feature of many neurodegenerative diseases, including proteinopathies such as Alzheimer's or Parkinson's disease, which are characterized by the deposition of aggregated proteins in the form of insoluble fibrils or plaques. The distinct molecular processes that eventually result in mitochondrial dysfunction during neurodegeneration are well studied but still not fully understood. However, defects in mitochondrial fission and fusion, mitophagy, oxidative phosphorylation and mitochondrial bioenergetics have been linked to cellular demise. These processes are influenced by the lipid environment within mitochondrial membranes as, besides membrane structure and curvature, recruitment and activity of different proteins also largely depend on the respective lipid composition. Hence, the interaction of neurotoxic proteins with certain lipids and the modification of lipid composition in different cell compartments, in particular mitochondria, decisively impact cell death associated with neurodegeneration. Here, we discuss the relevance of mitochondrial lipids in the pathological alterations that result in neuronal demise, focussing on proteinopathies.
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Affiliation(s)
- Andreas Aufschnaiter
- Institute of Molecular Biosciences, University of Graz, Humboldtstraße 50, 8010, Graz, Austria
| | - Verena Kohler
- Institute of Molecular Biosciences, University of Graz, Humboldtstraße 50, 8010, Graz, Austria
| | - Jutta Diessl
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrheniusväg 20C, 106 91, Stockholm, Sweden
| | - Carlotta Peselj
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrheniusväg 20C, 106 91, Stockholm, Sweden
| | - Didac Carmona-Gutierrez
- Institute of Molecular Biosciences, University of Graz, Humboldtstraße 50, 8010, Graz, Austria
| | - Walter Keller
- Institute of Molecular Biosciences, University of Graz, Humboldtstraße 50, 8010, Graz, Austria
| | - Sabrina Büttner
- Institute of Molecular Biosciences, University of Graz, Humboldtstraße 50, 8010, Graz, Austria.
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrheniusväg 20C, 106 91, Stockholm, Sweden.
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