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Dhakal S, Robang AS, Bhatt N, Puangmalai N, Fung L, Kayed R, Paravastu AK, Rangachari V. Distinct neurotoxic TDP-43 fibril polymorphs are generated by heterotypic interactions with α-Synuclein. J Biol Chem 2022; 298:102498. [PMID: 36116552 PMCID: PMC9587012 DOI: 10.1016/j.jbc.2022.102498] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 09/08/2022] [Accepted: 09/13/2022] [Indexed: 11/17/2022] Open
Abstract
Amyloid aggregates of specific proteins constitute important pathological hallmarks in many neurodegenerative diseases, defining neuronal degeneration and disease onset. Recently, increasing numbers of patients show comorbidities and overlaps between multiple neurodegenerative diseases, presenting distinct phenotypes. Such overlaps are often accompanied by colocalizations of more than one amyloid protein, prompting the question of whether direct interactions between different amyloid proteins could generate heterotypic amyloids. To answer this question, we investigated the effect of α-synuclein (αS) on the DNA-binding protein TDP-43 aggregation inspired by their coexistence in pathologies such as Lewy body dementia and limbic predominant age-related TDP-43 encephalopathy. We previously showed αS and prion-like C-terminal domain (PrLD) of TDP-43 synergistically interact to generate toxic heterotypic aggregates. Here, we extend these studies to investigate whether αS induces structurally and functionally distinct polymorphs of PrLD aggregates. Using αS-PrLD heterotypic aggregates generated in two different stoichiometric proportions, we show αS can affect PrLD fibril forms. PrLD fibrils show distinctive residue level signatures determined by solid state NMR, dye-binding capability, proteinase K (PK) stability, and thermal stability toward SDS denaturation. Furthremore, by gold nanoparticle labeling and transmission electron microscopy, we show the presence of both αS and PrLD proteins within the same fibrils, confirming the existence of heterotypic amyloid fibrils. We also observe αS and PrLD colocalize in the cytosol of neuroblastoma cells and show that the heterotypic PrLD fibrils selectively induce synaptic dysfunction in primary neurons. These findings establish the existence of heterotypic amyloid and provide a molecular basis for the observed overlap between synucleinopathies and TDP-43 proteinopathies.
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Affiliation(s)
- Shailendra Dhakal
- Department of Chemistry and Biochemistry, School of Mathematics and Natural Sciences, University of Southern Mississippi, Hattiesburg, Mississippi, USA; Center for Molecular and Cellular Biosciences, University of Southern Mississippi, Hattiesburg, Mississippi, USA
| | - Alicia S Robang
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Nemil Bhatt
- Mitchell Center for Neurodegenerative Disorders, University of Texas Medical Branch, Galveston, Texas, USA
| | - Nicha Puangmalai
- Mitchell Center for Neurodegenerative Disorders, University of Texas Medical Branch, Galveston, Texas, USA
| | - Leiana Fung
- Mitchell Center for Neurodegenerative Disorders, University of Texas Medical Branch, Galveston, Texas, USA
| | - Rakez Kayed
- Mitchell Center for Neurodegenerative Disorders, University of Texas Medical Branch, Galveston, Texas, USA
| | - Anant K Paravastu
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia, USA.
| | - Vijayaraghavan Rangachari
- Department of Chemistry and Biochemistry, School of Mathematics and Natural Sciences, University of Southern Mississippi, Hattiesburg, Mississippi, USA; Center for Molecular and Cellular Biosciences, University of Southern Mississippi, Hattiesburg, Mississippi, USA.
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Waker CA, Albers RE, Pye RL, Doliboa SR, Wyatt CN, Brown TL, Mayes DA. AMPK Knockdown in Placental Labyrinthine Progenitor Cells Results in Restriction of Critical Energy Resources and Terminal Differentiation Failure. Stem Cells Dev 2017; 26:808-817. [PMID: 28335680 DOI: 10.1089/scd.2016.0252] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Placental abnormalities can cause Pregnancy-Associated Disorders, including preeclampsia, intrauterine growth restriction, and placental insufficiency, resulting in complications for both the mother and fetus. Trophoblast cells within the labyrinthine layer of the placenta facilitate the exchange of nutrients, gases, and waste between mother and fetus; therefore, the development of this cell layer is critical for fetal development. As trophoblast cells differentiate, it is assumed their metabolism changes with their energy requirements. We hypothesize that proper regulation of trophoblast metabolism is a key component of normal placental development; therefore, we examined the role of AMP-activated kinase (AMPK, PRKAA1/2), a sensor of cellular energy status. Our previous studies have shown that AMPK knockdown alters both trophoblast differentiation and nutrient transport. In this study, AMPKα1/2 shRNA was used to investigate the metabolic effects of AMPK knockdown on SM10 placental labyrinthine progenitor cells before and after differentiation. Extracellular flux analysis confirmed that AMPK knockdown was sufficient to reduce trophoblast glycolysis, mitochondrial respiration, and ATP coupling efficiency. A reduction in AMPK in differentiated trophoblasts also resulted in increased mitochondrial volume. These data indicate that a reduction in AMPK disrupts cellular metabolism in both progenitors and differentiated placental trophoblasts. This disruption correlates to abortive trophoblast differentiation that may contribute to the development of Pregnancy-Associated Disorders.
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Affiliation(s)
- Christopher A Waker
- Department of Neuroscience, Cell Biology and Physiology, Wright State University Boonshoft School of Medicine , Dayton, Ohio
| | - Renee E Albers
- Department of Neuroscience, Cell Biology and Physiology, Wright State University Boonshoft School of Medicine , Dayton, Ohio
| | - Richard L Pye
- Department of Neuroscience, Cell Biology and Physiology, Wright State University Boonshoft School of Medicine , Dayton, Ohio
| | - Savannah R Doliboa
- Department of Neuroscience, Cell Biology and Physiology, Wright State University Boonshoft School of Medicine , Dayton, Ohio
| | - Christopher N Wyatt
- Department of Neuroscience, Cell Biology and Physiology, Wright State University Boonshoft School of Medicine , Dayton, Ohio
| | - Thomas L Brown
- Department of Neuroscience, Cell Biology and Physiology, Wright State University Boonshoft School of Medicine , Dayton, Ohio
| | - Debra A Mayes
- Department of Neuroscience, Cell Biology and Physiology, Wright State University Boonshoft School of Medicine , Dayton, Ohio
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Fenrich KK, Zhao EY, Wei Y, Garg A, Rose PK. Isolating specific cell and tissue compartments from 3D images for quantitative regional distribution analysis using novel computer algorithms. J Neurosci Methods 2014; 226:42-56. [PMID: 24487018 DOI: 10.1016/j.jneumeth.2014.01.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Revised: 01/08/2014] [Accepted: 01/13/2014] [Indexed: 11/30/2022]
Abstract
BACKGROUND Isolating specific cellular and tissue compartments from 3D image stacks for quantitative distribution analysis is crucial for understanding cellular and tissue physiology under normal and pathological conditions. Current approaches are limited because they are designed to map the distributions of synapses onto the dendrites of stained neurons and/or require specific proprietary software packages for their implementation. NEW METHOD To overcome these obstacles, we developed algorithms to Grow and Shrink Volumes of Interest (GSVI) to isolate specific cellular and tissue compartments from 3D image stacks for quantitative analysis and incorporated these algorithms into a user-friendly computer program that is open source and downloadable at no cost. RESULTS The GSVI algorithm was used to isolate perivascular regions in the cortex of live animals and cell membrane regions of stained spinal motoneurons in histological sections. We tracked the real-time, intravital biodistribution of injected fluorophores with sub-cellular resolution from the vascular lumen to the perivascular and parenchymal space following a vascular microlesion, and mapped the precise distributions of membrane-associated KCC2 and gephyrin immunolabeling in dendritic and somatic regions of spinal motoneurons. COMPARISON WITH EXISTING METHODS Compared to existing approaches, the GSVI approach is specifically designed for isolating perivascular regions and membrane-associated regions for quantitative analysis, is user-friendly, and free. CONCLUSIONS The GSVI algorithm is useful to quantify regional differences of stained biomarkers (e.g., cell membrane-associated channels) in relation to cell functions, and the effects of therapeutic strategies on the redistributions of biomolecules, drugs, and cells in diseased or injured tissues.
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Affiliation(s)
- Keith K Fenrich
- CIHR Group in Sensory-Motor Integration, Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada K7L 3N6; Center for Neuroscience Studies, Queen's University, Kingston, ON, Canada K7L 3N6; Aix Marseille University, Developmental Biology Institute of Marseille-Luminy (IBDML), CNRS 7288, Case 907 - Parc Scientifique de Luminy, 13009 Marseille, France; Faculty of Rehabilitation Medicine, University of Alberta, 3-88 Corbett Hall, Edmonton, AB, Canada T6G 2G4.
| | - Ethan Y Zhao
- CIHR Group in Sensory-Motor Integration, Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada K7L 3N6; Center for Neuroscience Studies, Queen's University, Kingston, ON, Canada K7L 3N6
| | - Yuan Wei
- CIHR Group in Sensory-Motor Integration, Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada K7L 3N6; Center for Neuroscience Studies, Queen's University, Kingston, ON, Canada K7L 3N6
| | - Anirudh Garg
- CIHR Group in Sensory-Motor Integration, Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada K7L 3N6; Center for Neuroscience Studies, Queen's University, Kingston, ON, Canada K7L 3N6
| | - P Ken Rose
- CIHR Group in Sensory-Motor Integration, Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada K7L 3N6; Center for Neuroscience Studies, Queen's University, Kingston, ON, Canada K7L 3N6.
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Fogarty MJ, Hammond LA, Kanjhan R, Bellingham MC, Noakes PG. A method for the three-dimensional reconstruction of Neurobiotin™-filled neurons and the location of their synaptic inputs. Front Neural Circuits 2013; 7:153. [PMID: 24101895 PMCID: PMC3787200 DOI: 10.3389/fncir.2013.00153] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Accepted: 09/12/2013] [Indexed: 12/15/2022] Open
Abstract
Here, we describe a robust method for mapping the number and type of neuro-chemically distinct synaptic inputs that a single reconstructed neuron receives. We have used individual hypoglossal motor neurons filled with Neurobiotin by semi-loose seal electroporation in thick brainstem slices. These filled motor neurons were then processed for excitatory and inhibitory synaptic inputs, using immunohistochemical-labeling procedures. For excitatory synapses, we used anti-VGLUT2 to locate glutamatergic pre-synaptic terminals and anti-PSD-95 to locate post-synaptic specializations on and within the surface of these filled motor neurons. For inhibitory synapses, we used anti-VGAT to locate GABAergic pre-synaptic terminals and anti-GABA-A receptor subunit α1 to locate the post-synaptic domain. The Neurobiotin-filled and immuno-labeled motor neuron was then processed for optical sectioning using confocal microscopy. The morphology of the motor neuron including its dendritic tree and the distribution of excitatory and inhibitory synapses were then determined by three-dimensional reconstruction using IMARIS software (Bitplane). Using surface rendering, fluorescence thresholding, and masking of unwanted immuno-labeling, tools found in IMARIS, we were able to obtain an accurate 3D structure of an individual neuron including the number and location of its glutamatergic and GABAergic synaptic inputs. The power of this method allows for a rapid morphological confirmation of the post-synaptic responses recorded by patch-clamp prior to Neurobiotin filling. Finally, we show that this method can be adapted to super-resolution microscopy techniques, which will enhance its applicability to the study of neural circuits at the level of synapses.
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Affiliation(s)
- Matthew J Fogarty
- School of Biomedical Sciences, The University of Queensland Brisbane, QLD, Australia
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