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Badal KK, Sadhu A, Raveendra BL, McCracken C, Lozano-Villada S, Shetty AC, Gillette P, Zhao Y, Stommes D, Fieber LA, Schmale MC, Mahurkar A, Hawkins RD, Puthanveettil SV. Single-neuron analysis of aging-associated changes in learning reveals impairments in transcriptional plasticity. Aging Cell 2024:e14228. [PMID: 38924663 DOI: 10.1111/acel.14228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2024] [Accepted: 05/02/2024] [Indexed: 06/28/2024] Open
Abstract
The molecular mechanisms underlying age-related declines in learning and long-term memory are still not fully understood. To address this gap, our study focused on investigating the transcriptional landscape of a singularly identified motor neuron L7 in Aplysia, which is pivotal in a specific type of nonassociative learning known as sensitization of the siphon-withdraw reflex. Employing total RNAseq analysis on a single isolated L7 motor neuron after short-term or long-term sensitization (LTS) training of Aplysia at 8, 10, and 12 months (representing mature, late mature, and senescent stages), we uncovered aberrant changes in transcriptional plasticity during the aging process. Our findings specifically highlight changes in the expression of messenger RNAs (mRNAs) that encode transcription factors, translation regulators, RNA methylation participants, and contributors to cytoskeletal rearrangements during learning and long noncoding RNAs (lncRNAs). Furthermore, our comparative gene expression analysis identified distinct transcriptional alterations in two other neurons, namely the motor neuron L11 and the giant cholinergic neuron R2, whose roles in LTS are not yet fully elucidated. Taken together, our analyses underscore cell type-specific impairments in the expression of key components related to learning and memory within the transcriptome as organisms age, shedding light on the complex molecular mechanisms driving cognitive decline during aging.
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Affiliation(s)
- Kerriann K Badal
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, Jupiter, Florida, USA
- Integrated Biology Graduate Program, Florida Atlantic University, Jupiter, Florida, USA
| | - Abhishek Sadhu
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, Jupiter, Florida, USA
| | - Bindu L Raveendra
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, Jupiter, Florida, USA
| | - Carrie McCracken
- The Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Sebastian Lozano-Villada
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, Jupiter, Florida, USA
- Harriet L. Wilkes Honors College, Florida Atlantic University, Jupiter, Florida, USA
| | - Amol C Shetty
- The Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Phillip Gillette
- National Resource for Aplysia, University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Sciences, Miami, Florida, USA
| | - Yibo Zhao
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, Jupiter, Florida, USA
| | - Dustin Stommes
- National Resource for Aplysia, University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Sciences, Miami, Florida, USA
| | - Lynne A Fieber
- National Resource for Aplysia, University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Sciences, Miami, Florida, USA
| | - Michael C Schmale
- National Resource for Aplysia, University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Sciences, Miami, Florida, USA
| | - Anup Mahurkar
- The Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Robert D Hawkins
- Department of Neuroscience, Columbia University, New York, New York, USA
- New York State Psychiatric Institute, New York, New York, USA
| | - Sathyanarayanan V Puthanveettil
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, Jupiter, Florida, USA
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Romussi S, Giunti S, Andersen N, De Rosa MJ. C. elegans: a prominent platform for modeling and drug screening in neurological disorders. Expert Opin Drug Discov 2024; 19:565-585. [PMID: 38509691 DOI: 10.1080/17460441.2024.2329103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 03/06/2024] [Indexed: 03/22/2024]
Abstract
INTRODUCTION Human neurodevelopmental and neurodegenerative diseases (NDevDs and NDegDs, respectively) encompass a broad spectrum of disorders affecting the nervous system with an increasing incidence. In this context, the nematode C. elegans, has emerged as a benchmark model for biological research, especially in the field of neuroscience. AREAS COVERED The authors highlight the numerous advantages of this tiny worm as a model for exploring nervous system pathologies and as a platform for drug discovery. There is a particular focus given to describing the existing models of C. elegans for the study of NDevDs and NDegDs. Specifically, the authors underscore their strong applicability in preclinical drug development. Furthermore, they place particular emphasis on detailing the common techniques employed to explore the nervous system in both healthy and diseased states. EXPERT OPINION Drug discovery constitutes a long and expensive process. The incorporation of invertebrate models, such as C. elegans, stands as an exemplary strategy for mitigating costs and expediting timelines. The utilization of C. elegans as a platform to replicate nervous system pathologies and conduct high-throughput automated assays in the initial phases of drug discovery is pivotal for rendering therapeutic options more attainable and cost-effective.
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Affiliation(s)
- Stefano Romussi
- Laboratorio de Neurobiología de Invertebrados, Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), UNS-CONICET, Bahía Blanca, Argentina
| | - Sebastián Giunti
- Laboratorio de Neurobiología de Invertebrados, Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), UNS-CONICET, Bahía Blanca, Argentina
- Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur (UNS), Bahía Blanca, Argentina
| | - Natalia Andersen
- Laboratorio de Neurobiología de Invertebrados, Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), UNS-CONICET, Bahía Blanca, Argentina
- Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur (UNS), Bahía Blanca, Argentina
| | - María José De Rosa
- Laboratorio de Neurobiología de Invertebrados, Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), UNS-CONICET, Bahía Blanca, Argentina
- Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur (UNS), Bahía Blanca, Argentina
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Gallo G. The Axonal Actin Filament Cytoskeleton: Structure, Function, and Relevance to Injury and Degeneration. Mol Neurobiol 2024:10.1007/s12035-023-03879-7. [PMID: 38216856 DOI: 10.1007/s12035-023-03879-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 12/13/2023] [Indexed: 01/14/2024]
Abstract
Early investigations of the neuronal actin filament cytoskeleton gave rise to the notion that, although growth cones exhibit high levels of actin filaments, the axon shaft exhibits low levels of actin filaments. With the development of new tools and imaging techniques, the axonal actin filament cytoskeleton has undergone a renaissance and is now an active field of research. This article reviews the current state of knowledge about the actin cytoskeleton of the axon shaft. The best understood forms of actin filament organization along axons are axonal actin patches and a submembranous system of rings that endow the axon with protrusive competency and structural integrity, respectively. Additional forms of actin filament organization along the axon have also been described and their roles are being elucidated. Extracellular signals regulate the axonal actin filament cytoskeleton and our understanding of the signaling mechanisms involved is being elaborated. Finally, recent years have seen advances in our perspective on how the axonal actin cytoskeleton is impacted by, and contributes to, axon injury and degeneration. The work to date has opened new venues and future research will undoubtedly continue to provide a richer understanding of the axonal actin filament cytoskeleton.
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Affiliation(s)
- Gianluca Gallo
- Department of Neural Sciences, Shriners Pediatric Research Center, Lewis Katz School of Medicine at Temple University, 3500 North Broad St, Philadelphia, PA, 19140, USA.
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Rahimpouresfahani F, Tabatabaei N, Rezai P. High-throughput light sheet imaging of adult and larval C. elegans Parkinson's disease model using a low-cost optofluidic device and a fluorescent microscope. RSC Adv 2024; 14:626-639. [PMID: 38173569 PMCID: PMC10759043 DOI: 10.1039/d3ra06323b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Accepted: 11/30/2023] [Indexed: 01/05/2024] Open
Abstract
Recent advancements at the interface of microfluidics technology and light sheet fluorescence microscopy have opened the door for high-throughput and high-content investigation of C. elegans disease models. In this paper, we report on the development of a simple, miniaturized, and low-cost optofluidic platform that can be added to a conventional inverted fluorescent microscope for continuous light sheet imaging of transgenic worm populations with high lateral and axial resolutions of 1.1 µm and 2.4 µm, respectively. The optofluidic device is made entirely of PDMS with integrated optics for light sheet generation. Laser excitation is delivered to the device via a low-cost free space laser, and cross-sections of worm populations are imaged as they pass continuously through a channel. Results show the platform can image NW1229 whole worms with pan-neural fluorescent expression at a throughput of >20 worms per minute at L3 and young adult (YA) stages. As a benchmark test, we show that the low-cost device can quantify the reduced neuronal expressions of L3 and YA NW1229 worms when exposed to 500 µM 6-OHDA neurodegenerative agent. Following the benchmark validation, we utilized the platform in a novel application for imaging human alpha-synuclein reporter in populations of Parkinson's transgenic model (ERS100). Results show the ability of the low-cost platform to reliably detect and quantify the anomalous neural phenotypic changes in ERS100 populations at L3 and YA stages with high spatial resolution. The findings of this study show the potential of our low-cost optofluidic add-on platform to equip conventional fluorescent microscopes with light sheet capability for quantitative phenotypic studies of transgenic C. elegans at high resolution and throughput.
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Affiliation(s)
- Faraz Rahimpouresfahani
- Department of Mechanical Engineering, York University 4700 Keele St Toronto M3J 1P3 Ontario Canada +1-416-7362100
| | - Nima Tabatabaei
- Department of Mechanical Engineering, York University 4700 Keele St Toronto M3J 1P3 Ontario Canada +1-416-7362100
| | - Pouya Rezai
- Department of Mechanical Engineering, York University 4700 Keele St Toronto M3J 1P3 Ontario Canada +1-416-7362100
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Doser R, Knight KM, Deihl E, Hoerndli F. Subcellular Imaging of Neuronal Calcium Handling In Vivo. J Vis Exp 2023:10.3791/64928. [PMID: 37010315 PMCID: PMC10937071 DOI: 10.3791/64928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2023] Open
Abstract
Calcium (Ca2+) imaging has been largely used to examine neuronal activity, but it is becoming increasingly clear that subcellular Ca2+ handling is a crucial component of intracellular signaling. The visualization of subcellular Ca2+ dynamics in vivo, where neurons can be studied in their native, intact circuitry, has proven technically challenging in complex nervous systems. The transparency and relatively simple nervous system of the nematode Caenorhabditis elegans enable the cell-specific expression and in vivo visualization of fluorescent tags and indicators. Among these are fluorescent indicators that have been modified for use in the cytoplasm as well as various subcellular compartments, such as the mitochondria. This protocol enables non-ratiometric Ca2+ imaging in vivo with a subcellular resolution that permits the analysis of Ca2+ dynamics down to the level of individual dendritic spines and mitochondria. Here, two available genetically encoded indicators with different Ca2+ affinities are used to demonstrate the use of this protocol for measuring relative Ca2+ levels within the cytoplasm or mitochondrial matrix in a single pair of excitatory interneurons (AVA). Together with the genetic manipulations and longitudinal observations possible in C. elegans, this imaging protocol may be useful for answering questions regarding how Ca2+ handling regulates neuronal function and plasticity.
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Affiliation(s)
- Rachel Doser
- Department of Biomedical Sciences, Colorado State University College of Veterinary Medicine and Biomedical Sciences
| | - Kaz M Knight
- Department of Biomedical Sciences, Colorado State University College of Veterinary Medicine and Biomedical Sciences; Cellular and Molecular Biology Graduate Program, Colorado State University College of Veterinary Medicine and Biomedical Sciences
| | - Ennis Deihl
- Department of Biomedical Sciences, Colorado State University College of Veterinary Medicine and Biomedical Sciences
| | - Frederic Hoerndli
- Department of Biomedical Sciences, Colorado State University College of Veterinary Medicine and Biomedical Sciences;
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6
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Yuan Y, Xin K, Liu J, Zhao P, Lu MP, Yan Y, Hu Y, Huo H, Li Z, Fang T. A GNN-based model for capturing spatio-temporal changes in locomotion behaviors of aging C. elegans. Comput Biol Med 2023; 155:106694. [PMID: 36812812 DOI: 10.1016/j.compbiomed.2023.106694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 01/27/2023] [Accepted: 02/14/2023] [Indexed: 02/17/2023]
Abstract
Investigating the locomotion of aging C. elegans is an important way for understanding the basic mechanisms behind age-related changes in organisms. However, the locomotion of aging C. elegans is often quantified using insufficient physical variables, which makes it challenging to capture essential dynamics. To study changes in the locomotion pattern of aging C. elegans, we developed a novel data-driven model based on graph neural networks, in which the C. elegans body is modeled as a long chain with interactions within and between adjacent segments, and their interactions are described by high-dimensional variables. Using this model, we discovered that each segment of the C. elegans body generally tends to maintain its locomotion, i.e., tries to keep the bending angle unchanged, and expects to change the locomotion of the adjacent segments. The ability to maintain its locomotion strengthens with age. Besides, a subtle distinguish in the changes in the locomotion pattern of C. elegans at various aging stages were observed. Our model is anticipated to provide a data-driven method for quantifying the changes in the locomotion pattern of aging C. elegans and for mining the underlying causes of these changes.
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Affiliation(s)
- Ye Yuan
- Institute of Machine Intelligence, University of Shanghai for Science and Technology, Shanghai, 200093, China; Department of Automation, Shanghai Jiao Tong University, Shanghai, 200240, China; Key Laboratory of System Control and Information Processing, Ministry of Education, China
| | - Kuankuan Xin
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Jian Liu
- Department of Automation, Shanghai Jiao Tong University, Shanghai, 200240, China; Key Laboratory of System Control and Information Processing, Ministry of Education, China
| | - Peng Zhao
- Department of Automation, Shanghai Jiao Tong University, Shanghai, 200240, China; Key Laboratory of System Control and Information Processing, Ministry of Education, China
| | - Man Pok Lu
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Yuner Yan
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Yuchen Hu
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Hong Huo
- Department of Automation, Shanghai Jiao Tong University, Shanghai, 200240, China; Key Laboratory of System Control and Information Processing, Ministry of Education, China.
| | - Zhaoyu Li
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia.
| | - Tao Fang
- Department of Automation, Shanghai Jiao Tong University, Shanghai, 200240, China; Key Laboratory of System Control and Information Processing, Ministry of Education, China.
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Jîtcă G, Ősz BE, Vari CE, Rusz CM, Tero-Vescan A, Pușcaș A. Cannabidiol: Bridge between Antioxidant Effect, Cellular Protection, and Cognitive and Physical Performance. Antioxidants (Basel) 2023; 12:antiox12020485. [PMID: 36830042 PMCID: PMC9952814 DOI: 10.3390/antiox12020485] [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: 01/13/2023] [Revised: 02/08/2023] [Accepted: 02/13/2023] [Indexed: 02/17/2023] Open
Abstract
The literature provides scientific evidence for the beneficial effects of cannabidiol (CBD), and these effects extend beyond epilepsy treatment (e.g., Lennox-Gastaut and Dravet syndromes), notably the influence on oxidative status, neurodegeneration, cellular protection, cognitive function, and physical performance. However, products containing CBD are not allowed to be marketed everywhere in the world, which may ultimately have a negative effect on health as a result of the uncontrolled CBD market. After the isolation of CBD follows the discovery of CB1 and CB2 receptors and the main enzymatic components (diacylglycerol lipase (DAG lipase), monoacyl glycerol lipase (MAGL), fatty acid amino hydrolase (FAAH)). At the same time, the antioxidant potential of CBD is due not only to the molecular structure but also to the fact that this compound increases the expression of the main endogenous antioxidant systems, superoxide dismutase (SOD), and glutathione peroxidase (GPx), through the nuclear complex erythroid 2-related factor (Nrf2)/Keep1. Regarding the role in the control of inflammation, this function is exercised by inhibiting (nuclear factor kappa B) NF-κB, and also the genes that encode the expression of molecules with a pro-inflammatory role (cytokines and metalloproteinases). The other effects of CBD on cognitive function and physical performance should not be excluded. In conclusion, the CBD market needs to be regulated more thoroughly, given the previously listed properties, with the mention that the safety profile is a very good one.
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Affiliation(s)
- George Jîtcă
- Department of Pharmacology and Clinical Pharmacy, Faculty of Pharmacy, George Emil Palade University of Medicine, Pharmacy, Science and Technology of Târgu Mureș, 540139 Târgu Mureș, Romania
| | - Bianca E. Ősz
- Department of Pharmacology and Clinical Pharmacy, Faculty of Pharmacy, George Emil Palade University of Medicine, Pharmacy, Science and Technology of Târgu Mureș, 540139 Târgu Mureș, Romania
- Correspondence:
| | - Camil E. Vari
- Department of Pharmacology and Clinical Pharmacy, Faculty of Pharmacy, George Emil Palade University of Medicine, Pharmacy, Science and Technology of Târgu Mureș, 540139 Târgu Mureș, Romania
| | - Carmen-Maria Rusz
- Doctoral School of Medicine and Pharmacy, I.O.S.U.D, George Emil Palade University of Medicine, Pharmacy, Science and Technology of Târgu Mureș, 540139 Târgu Mureș, Romania
| | - Amelia Tero-Vescan
- Department of Biochemistry, Faculty of Pharmacy, George Emil Palade University of Medicine, Pharmacy, Science and Technology of Târgu Mureș, 540139 Târgu Mureș, Romania
| | - Amalia Pușcaș
- Department of Biochemistry, Faculty of Pharmacy, George Emil Palade University of Medicine, Pharmacy, Science and Technology of Târgu Mureș, 540139 Târgu Mureș, Romania
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Cho I, Song HO, Ji HE, Yang S, Cho JH. BAM15 Relieves Neurodegeneration in Aged Caenorhabditis elegans and Extends Lifespan. Metabolites 2022; 12:1129. [PMID: 36422268 PMCID: PMC9698188 DOI: 10.3390/metabo12111129] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 11/15/2022] [Accepted: 11/16/2022] [Indexed: 09/01/2023] Open
Abstract
BAM15 was recently screened as a protonophore uncoupler specifically for the mitochondrial membrane but not the plasma membrane. It is equally as potent as FCCP, but less toxic. Previously, mitochondrial uncoupling via DNP alleviates neurodegeneration in the nematode Caenorhabditis elegans during aging. Therefore, we investigated whether BAM15 uncouplers could phenotypically and functionally reduce neuronal defects in aged nematodes. We observed green fluorescence protein-tagged mechanosensory neurons and performed touch and chemotaxis assays during aging. Wild-type animals treated with both 50 µM BAM15 and 10 µM DNP showed reduced mechanosensory neuronal defects during aging, which correlates with the maintenance of touch responses and short-term memory during aging. Uncoupler mutant ucp-4 also responded the same way as the wild-type, reducing neurodegeneration in 50 µM BAM15 and 10 µM DNP-treated animals compared to the DMSO control. These results suggest that 50 µM BAM15 alleviates neurodegeneration phenotypically and functionally in C. elegans during aging, potentially through mitochondrial uncoupling. In accordance with the preserved neuronal shape and function in aged C. elegans, 50 µM BAM15 extended the mean lifespan of both wild-type and ucp-4 mutants.
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Affiliation(s)
- Injeong Cho
- Department of Biology Education, College of Education, Chosun University, Gwangju 61452, Republic of Korea
| | - Hyun-Ok Song
- Department of Infection Biology, Wonkwang University School of Medicine, Iksan 54538, Republic of Korea
| | - Ha Eun Ji
- Department of Biology Education, College of Education, Chosun University, Gwangju 61452, Republic of Korea
| | - Sungtae Yang
- Department of Microbiology, School of Medicine, Chosun University, Gwangju 61452, Republic of Korea
| | - Jeong Hoon Cho
- Department of Biology Education, College of Education, Chosun University, Gwangju 61452, Republic of Korea
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9
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Wang Z, Zheng P, Chen X, Xie Y, Weston-Green K, Solowij N, Chew YL, Huang XF. Cannabidiol induces autophagy and improves neuronal health associated with SIRT1 mediated longevity. GeroScience 2022; 44:1505-1524. [PMID: 35445360 PMCID: PMC9213613 DOI: 10.1007/s11357-022-00559-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 03/30/2022] [Indexed: 11/30/2022] Open
Abstract
Autophagy is a catabolic process to eliminate defective cellular molecules via lysosome-mediated degradation. Dysfunctional autophagy is associated with accelerated aging, whereas stimulation of autophagy could have potent anti-aging effects. We report that cannabidiol (CBD), a natural compound from Cannabis sativa, extends lifespan and rescues age-associated physiological declines in C. elegans. CBD promoted autophagic flux in nerve-ring neurons visualized by a tandem-tagged LGG-1 reporter during aging in C. elegans. Similarly, CBD activated autophagic flux in hippocampal and SH-SY5Y neurons. Furthermore, CBD-mediated lifespan extension was dependent on autophagy genes (bec-1, vps-34, and sqst-1) confirmed by RNAi knockdown experiments. C. elegans neurons have previously been shown to accumulate aberrant morphologies, such as beading and blebbing, with increasing age. Interestingly, CBD treatment slowed the development of these features in anterior and posterior touch receptor neurons (TRN) during aging. RNAi knockdown experiments indicated that CBD-mediated age-associated morphological changes in TRNs require bec-1 and sqst-1, not vps-34. Further investigation demonstrated that CBD-induced lifespan extension and increased neuronal health require sir-2.1/SIRT1. These findings collectively indicate the anti-aging benefits of CBD treatment, in both in vitro and in vivo models, and its potential to improve neuronal health and longevity.
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Affiliation(s)
- Zhizhen Wang
- Australian Centre for Cannabinoid Clinical and Research Excellence (ACRE), New Lambton Heights, NSW, Australia.,Illawarra Health and Medical Research Institute (IHMRI) and School of Medicine, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Peng Zheng
- Illawarra Health and Medical Research Institute (IHMRI) and School of Medicine, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Xi Chen
- Illawarra Health and Medical Research Institute (IHMRI) and School of Medicine, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Yuanyi Xie
- Illawarra Health and Medical Research Institute (IHMRI) and School of Medicine, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Katrina Weston-Green
- Australian Centre for Cannabinoid Clinical and Research Excellence (ACRE), New Lambton Heights, NSW, Australia.,Illawarra Health and Medical Research Institute (IHMRI) and School of Medicine, University of Wollongong, Wollongong, NSW, 2522, Australia.,Molecular Horizons, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Nadia Solowij
- Australian Centre for Cannabinoid Clinical and Research Excellence (ACRE), New Lambton Heights, NSW, Australia.,Illawarra Health and Medical Research Institute (IHMRI) and School of Medicine, University of Wollongong, Wollongong, NSW, 2522, Australia.,School of Psychology, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Yee Lian Chew
- Illawarra Health and Medical Research Institute (IHMRI) and School of Medicine, University of Wollongong, Wollongong, NSW, 2522, Australia. .,Molecular Horizons, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW, 2522, Australia. .,Flinders Health and Medical Research Institute and College of Medicine and Public Health, Flinders University, Bedford Park, South Australia, 5042, Australia.
| | - Xu-Feng Huang
- Australian Centre for Cannabinoid Clinical and Research Excellence (ACRE), New Lambton Heights, NSW, Australia. .,Illawarra Health and Medical Research Institute (IHMRI) and School of Medicine, University of Wollongong, Wollongong, NSW, 2522, Australia. .,Molecular Horizons, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW, 2522, Australia.
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Dey S, Ghosh-Roy A. In vivo Assessment of Microtubule Dynamics and Orientation in Caenorhabditis elegans Neurons. J Vis Exp 2021:10.3791/62744. [PMID: 34866634 PMCID: PMC7614928 DOI: 10.3791/62744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
In neurons, microtubule orientation has been a key assessor to identify axons that have plus-end out microtubules and dendrites that generally have mixed orientation. Here we describe methods to label, image, and analyze the microtubule dynamics and growth during the development and regeneration of touch neurons in C. elegans. Using genetically encoded fluorescent reporters of microtubule tips, we imaged the axonal microtubules. The local changes in microtubule behavior that initiates axon regeneration following axotomy can be quantified using this protocol. This assay is adaptable to other neurons and genetic backgrounds to investigate the regulation of microtubule dynamics in various cellular processes.
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11
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Koch SC, Nelson A, Hartenstein V. Structural aspects of the aging invertebrate brain. Cell Tissue Res 2021; 383:931-947. [PMID: 33409654 PMCID: PMC7965346 DOI: 10.1007/s00441-020-03314-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 09/28/2020] [Indexed: 11/26/2022]
Abstract
Aging is characterized by a decline in neuronal function in all animal species investigated so far. Functional changes are accompanied by and may be in part caused by, structurally visible degenerative changes in neurons. In the mammalian brain, normal aging shows abnormalities in dendrites and axons, as well as ultrastructural changes in synapses, rather than global neuron loss. The analysis of the structural features of aging neurons, as well as their causal link to molecular mechanisms on the one hand, and the functional decline on the other hand is crucial in order to understand the aging process in the brain. Invertebrate model organisms like Drosophila and C. elegans offer the opportunity to apply a forward genetic approach to the analysis of aging. In the present review, we aim to summarize findings concerning abnormalities in morphology and ultrastructure in invertebrate brains during normal aging and compare them to what is known for the mammalian brain. It becomes clear that despite of their considerably shorter life span, invertebrates display several age-related changes very similar to the mammalian condition, including the retraction of dendritic and axonal branches at specific locations, changes in synaptic density and increased accumulation of presynaptic protein complexes. We anticipate that continued research efforts in invertebrate systems will significantly contribute to reveal (and possibly manipulate) the molecular/cellular pathways leading to neuronal aging in the mammalian brain.
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Affiliation(s)
- Sandra C Koch
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles (UCLA), Los Angeles, California, USA
| | - Annie Nelson
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles (UCLA), Los Angeles, California, USA
| | - Volker Hartenstein
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles (UCLA), Los Angeles, California, USA.
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12
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Cho I, Song H, Cho JH. Flavonoids mitigate neurodegeneration in aged Caenorhabditis elegans by mitochondrial uncoupling. Food Sci Nutr 2020; 8:6633-6642. [PMID: 33312547 PMCID: PMC7723185 DOI: 10.1002/fsn3.1956] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 09/27/2020] [Accepted: 10/03/2020] [Indexed: 12/11/2022] Open
Abstract
Dietary supplementation of flavonoids has been shown to reduce the severity of neurodegenerative disorders such as dementia, Parkinson's disease, and Alzheimer's disease by their antioxidant effects. However, their low bioavailabilityin vivo raises the question of how much their antioxidant capacity actually contributes to the mitigating effects. The physicochemical properties of flavonoids suggest they could function as mitochondrial uncouplers. Moreover, mitochondrial uncoupling alleviated neurodegeneration in Caenorhabditis elegans during aging in previous research. Therefore, we investigated whether various flavonoids (fisetin, quercetin, apigenin, chrysin, catechin, and naringenin) could reduce neuronal defects by mitochondrial uncoupling in C. elegans. Both neuronal defects and mitochondrial membrane potential were reduced in aged worms in nearly all of the flavonoid treatments suggesting that flavonoids may reduce neurodegeneration in C. elegans. However, there was no significant reduction of neuronal defects in mitophagy-deficient pink-1/pdr-1 double mutants under flavonoid treatments. These results suggest that flavonoids could function as mitochondrial uncouplers to mitigate neurodegeneration in aged C. elegans, possibly via a PINK1/Parkin mitophagy process.
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Affiliation(s)
- Injeong Cho
- Department of Biology EducationCollege of EducationChosun UniversityGwangjuKorea
| | - Hyun‐Ok Song
- Department of Infection BiologyWonkwang University School of MedicineIksanJeonbukKorea
| | - Jeong Hoon Cho
- Department of Biology EducationCollege of EducationChosun UniversityGwangjuKorea
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13
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Tauopathy-associated tau modifications selectively impact neurodegeneration and mitophagy in a novel C. elegans single-copy transgenic model. Mol Neurodegener 2020; 15:65. [PMID: 33168053 PMCID: PMC7654055 DOI: 10.1186/s13024-020-00410-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 10/07/2020] [Indexed: 12/29/2022] Open
Abstract
Background A defining pathological hallmark of the progressive neurodegenerative disorder Alzheimer’s disease (AD) is the accumulation of misfolded tau with abnormal post-translational modifications (PTMs). These include phosphorylation at Threonine 231 (T231) and acetylation at Lysine 274 (K274) and at Lysine 281 (K281). Although tau is recognized to play a central role in pathogenesis of AD, the precise mechanisms by which these abnormal PTMs contribute to the neural toxicity of tau is unclear. Methods Human 0N4R tau (wild type) was expressed in touch receptor neurons of the genetic model organism C. elegans through single-copy gene insertion. Defined mutations were then introduced into the single-copy tau transgene through CRISPR-Cas9 genome editing. These mutations included T231E, to mimic phosphorylation of a commonly observed pathological epitope, and K274/281Q, to mimic disease-associated lysine acetylation – collectively referred as “PTM-mimetics” – as well as a T231A phosphoablation mutant. Stereotypical touch response assays were used to assess behavioral defects in the transgenic strains as a function of age. Genetically-encoded fluorescent biosensors were expressed in touch neurons and used to measure neuronal morphology, mitochondrial morphology, mitophagy, and macro autophagy. Results Unlike existing tau overexpression models, C. elegans single-copy expression of tau did not elicit overt pathological phenotypes at baseline. However, strains expressing disease associated PTM-mimetics (T231E and K274/281Q) exhibited reduced touch sensation and neuronal morphological abnormalities that increased with age. In addition, the PTM-mimetic mutants lacked the ability to engage neuronal mitophagy in response to mitochondrial stress. Conclusions Limiting the expression of tau results in a genetic model where modifications that mimic pathologic tauopathy-associated PTMs contribute to cryptic, stress-inducible phenotypes that evolve with age. These findings and their relationship to mitochondrial stress provides a new perspective into the pathogenic mechanisms underlying AD. Supplementary information The online version contains supplementary material available at 10.1186/s13024-020-00410-7.
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14
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Liang JJH, McKinnon IA, Rankin CH. The contribution of C. elegans neurogenetics to understanding neurodegenerative diseases. J Neurogenet 2020; 34:527-548. [DOI: 10.1080/01677063.2020.1803302] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Joseph J. H. Liang
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
| | - Issa A. McKinnon
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
| | - Catharine H. Rankin
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
- Department of Psychology, University of British Columbia, Vancouver, Canada
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15
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Understanding the role of p38 and JNK mediated MAPK pathway in response to UV-A induced photoaging in Caenorhabditis elegans. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2020; 205:111844. [PMID: 32172136 DOI: 10.1016/j.jphotobiol.2020.111844] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 02/09/2020] [Accepted: 03/02/2020] [Indexed: 11/20/2022]
Abstract
Premature aging of the skin, principally induced by the UV radiations is called as photoaging, characterized by an increase in the level of ROS and the damage of the collagen layer leading to the damage of the cells. Mitogen activated Protein kinase (MAPK) pathway is known to mediate photoaging by controlling the level of ROS and initiating detoxification. Caenorhabditis elegans, a known model to analyze photoaging was used to understand the role of MAPK pathway (p38 and JNK) during UV-A mediated photoaging. Gene specific mutants of p38 MAPK pathway showed reduced survival when exposed to UV-A suggesting that UV-A mediated photoaging was dependent on this pathway. Also, the role of SKN-1 in eliciting response against UV-A was analyzed with the help of GFP tagged strains and qPCR analysis. Further, UV-A did not have any impact on the lifespan of JNK pathway mutants suggesting the importance of the pathway in eliciting a response against UV-A exposure, which was further validated by Western blot analysis. Overall, this study suggests that MAPK pathway could play an important part in initiating and eliciting a response by the host against UV-A exposure, by which it could be used as a marker to analyze the effects of photoaging.
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16
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Cogliati S, Clementi V, Francisco M, Crespo C, Argañaraz F, Grau R. Bacillus Subtilis Delays Neurodegeneration and Behavioral Impairment in the Alzheimer’s Disease Model Caenorhabditis Elegans. J Alzheimers Dis 2020; 73:1035-1052. [DOI: 10.3233/jad-190837] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Sebastián Cogliati
- Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, CONICET – Rosario, Argentina
| | - Victoria Clementi
- Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, CONICET – Rosario, Argentina
| | - Marcos Francisco
- Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, CONICET – Rosario, Argentina
| | - Cira Crespo
- Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, CONICET – Rosario, Argentina
| | - Federico Argañaraz
- Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, CONICET – Rosario, Argentina
| | - Roberto Grau
- Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, CONICET – Rosario, Argentina
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17
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Zhang S, Li F, Zhou T, Wang G, Li Z. Caenorhabditis elegans as a Useful Model for Studying Aging Mutations. Front Endocrinol (Lausanne) 2020; 11:554994. [PMID: 33123086 PMCID: PMC7570440 DOI: 10.3389/fendo.2020.554994] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 09/01/2020] [Indexed: 12/12/2022] Open
Abstract
The Caenorhabditis elegans genome possesses homologs of about two-thirds of all human disease genes. Based on its physiological aging characteristics and superiority, the use of C. elegans as a model system for studies on aging, age-related diseases, mechanisms of longevity, and drug screening has been widely acknowledged in recent decades. Lifespan increasing mutations in C. elegans were found to delay aging by impinging several signaling pathways and related epigenetic modifications, including the insulin/IGF-1 signaling (IIS), AMP-activated protein kinase (AMPK), and mechanistic target of rapamycin (mTOR) pathways. Interestingly, dietary restriction (DR) has been shown to increase the lifespan of numerous metazoans and protect them from multiple age-related pathologies. However, the underlying molecular mechanisms are unclear. In recent decades, C. elegans has been used as a unique model system for high-throughput drug screening. Here, we review C. elegans mutants exhibiting increased in lifespan and age-dependent changes under DR, as well as the utility of C. elegans for drug screening. Thus, we provide evidence for the use of this model organism in research on the prevention of aging.
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18
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Germany EM, Zahayko N, Khalimonchuk O. Isolation of Specific Neuron Populations from Roundworm Caenorhabditis elegans. J Vis Exp 2019. [PMID: 31449245 DOI: 10.3791/60145] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
During the aging process, many cells accumulate high levels of damage leading to cellular dysfunction, which underlies many geriatric and pathological conditions. Post-mitotic neurons represent a major cell type affected by aging. Although multiple mammalian models of neuronal aging exist, they are challenging and expensive to establish. The roundworm Caenorhabditis elegans is a powerful model to study neuronal aging, as these animals have short lifespan, an available robust genetic toolbox, and well-cataloged nervous system. The method presented herein allows for seamless isolation of specific cells based on the expression of a transgenic green fluorescent protein (GFP). Transgenic animal lines expressing GFP under distinct, cell type-specific promoters are digested to remove the outer cuticle and gently mechanically disrupted to produce slurry containing various cell types. The cells of interest are then separated from non-target cells through fluorescence-activated cell sorting, or by anti-GFP-coupled magnetic beads. The isolated cells can then be cultured for a limited time or immediately used for cell-specific ex vivo analyses such as transcriptional analysis by real time quantitative PCR. Thus, this protocol allows for rapid and robust analysis of cell-specific responses within different neuronal populations in C. elegans.
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Affiliation(s)
| | | | - Oleh Khalimonchuk
- Department of Biochemistry, University of Nebraska; Nebraska Redox Biology Center, University of Nebraska; Nebraska Center for Integrated Biomolecular Communication, University of Nebraska; Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center;
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19
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In-Vivo Quantitative Image Analysis of Age-Related Morphological Changes of C. elegans Neurons Reveals a Correlation between Neurite Bending and Novel Neurite Outgrowths. eNeuro 2019; 6:ENEURO.0014-19.2019. [PMID: 31217194 PMCID: PMC6620389 DOI: 10.1523/eneuro.0014-19.2019] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 05/08/2019] [Accepted: 05/14/2019] [Indexed: 12/24/2022] Open
Abstract
The aging of the human brain in the absence of diseases is accompanied by subtle changes of neuronal morphology, such as dendrite restructuring, neuronal sprouting, and synaptic deteriorations, rather than neurodegeneration or gross deterioration. Similarly, the nervous system of Caenorhabditis elegans does not show neurodegeneration or gross deterioration during normal aging, but displays subtle alterations in neuronal morphology. The occurrence of these age-dependent abnormalities is stochastic and dynamic, which poses a major challenge to fully capture them for quantitative comparison. Here, we developed a semi-automated pipeline for quantitative image analysis of these features during aging. We employed and evaluated this pipeline herein to reproduce findings from previous studies using visual inspection of neuronal morphology. Importantly, our approach can also quantify additional features, such as soma volume, the length of neurite outgrowths, and their location along the aged neuron. We found that, during aging, the soma of neurons decreases in volume, whereas the number and length of neurite outgrowths from the soma both increase. Long-lived animals showed less decrease in soma volume, fewer and shorter neurite outgrowths, and protection against abnormal sharp bends preferentially localized at the distal part of the dendrites during aging. We found a correlation of sharp bends with neurite outgrowth, suggesting the hypothesis that sharp bends might proceed neurite outgrowths. Thus, our semi-automated pipeline can help researchers to obtain and analyze quantitative datasets of this stochastic process for comparison across genotypes and to identify correlations to facilitate the generation of novel hypothesis.
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20
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Son HG, Altintas O, Kim EJE, Kwon S, Lee SV. Age-dependent changes and biomarkers of aging in Caenorhabditis elegans. Aging Cell 2019; 18:e12853. [PMID: 30734981 PMCID: PMC6413654 DOI: 10.1111/acel.12853] [Citation(s) in RCA: 97] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 08/28/2018] [Accepted: 09/11/2018] [Indexed: 12/13/2022] Open
Abstract
Caenorhabditis elegans is an exceptionally valuable model for aging research because of many advantages, including its genetic tractability, short lifespan, and clear age‐dependent physiological changes. Aged C. elegans display a decline in their anatomical and functional features, including tissue integrity, motility, learning and memory, and immunity. Caenorhabditis elegans also exhibit many age‐associated changes in the expression of microRNAs and stress‐responsive genes and in RNA and protein quality control systems. Many of these age‐associated changes provide information on the health of the animals and serve as valuable biomarkers for aging research. Here, we review the age‐dependent changes in C. elegans and their utility as aging biomarkers indicative of the physiological status of aging.
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Affiliation(s)
- Heehwa G. Son
- Department of Life Sciences Pohang University of Science and Technology Pohang South Korea
| | - Ozlem Altintas
- School of Interdisciplinary Bioscience and Bioengineering Pohang University of Science and Technology Pohang South Korea
| | - Eun Ji E. Kim
- Department of Life Sciences Pohang University of Science and Technology Pohang South Korea
| | - Sujeong Kwon
- Department of Life Sciences Pohang University of Science and Technology Pohang South Korea
| | - Seung‐Jae V. Lee
- Department of Life Sciences Pohang University of Science and Technology Pohang South Korea
- School of Interdisciplinary Bioscience and Bioengineering Pohang University of Science and Technology Pohang South Korea
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21
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Chen P, Ijomone OM, Lee KH, Aschner M. Caenorhabditis elegans and its applicability to studies on restless legs syndrome. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2019; 84:147-174. [PMID: 31229169 DOI: 10.1016/bs.apha.2018.12.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Restless legs syndrome (RLS) is a common neurological disorder in the United States. This disorder is characterized by an irresistible urge to move the legs, although the symptoms vary in a wide range. The pathobiology of RLS has been linked to iron (Fe) deficiency and dopaminergic (DAergic) dysfunction. Several genetic factors have been reported to increase the risk of RLS. Caenorhabditis elegans (C. elegans) is a well-established animal model with a fully sequenced genome, which is highly conserved with mammals. Given the detailed knowledge of its genomic architecture, ease of genetic manipulation and conserved biosynthetic and metabolic pathways, as well as its small size, ease of maintenance, speedy generation time and large brood size, C. elegans provides numerous advantages in studying RLS-associated gene-environment interactions. Here we will review current knowledge about RLS symptoms, pathology and treatments, and discuss the application of C. elegans in RLS study, including the worm homologous genes and methods that could be performed to advance the pathophysiology RLS.
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Affiliation(s)
- Pan Chen
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Omamuyovwi Meashack Ijomone
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, United States; Department of Human Anatomy, Federal University of Technology, Akure, Nigeria
| | - Kun He Lee
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, United States.
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22
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Teoh JS, Wong MYY, Vijayaraghavan T, Neumann B. Bridging the gap: axonal fusion drives rapid functional recovery of the nervous system. Neural Regen Res 2018; 13:591-594. [PMID: 29722300 PMCID: PMC5950658 DOI: 10.4103/1673-5374.230271] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Injuries to the central or peripheral nervous system frequently cause long-term disabilities because damaged neurons are unable to efficiently self-repair. This inherent deficiency necessitates the need for new treatment options aimed at restoring lost function to patients. Compared to humans, a number of species possess far greater regenerative capabilities, and can therefore provide important insights into how our own nervous systems can be repaired. In particular, several invertebrate species have been shown to rapidly initiate regeneration post-injury, allowing separated axon segments to re-join. This process, known as axonal fusion, represents a highly efficient repair mechanism as a regrowing axon needs to only bridge the site of damage and fuse with its separated counterpart in order to re-establish its original structure. Our recent findings in the nematode Caenorhabditis elegans have expanded the promise of axonal fusion by demonstrating that it can restore complete function to damaged neurons. Moreover, we revealed the importance of injury-induced changes in the composition of the axonal membrane for mediating axonal fusion, and discovered that the level of axonal fusion can be enhanced by promoting a neuron's intrinsic growth potential. A complete understanding of the molecular mechanisms controlling axonal fusion may permit similar approaches to be applied in a clinical setting.
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Affiliation(s)
- Jean-Sébastien Teoh
- Neuroscience Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, Australia
| | - Michelle Yu-Ying Wong
- Neuroscience Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, Australia
| | - Tarika Vijayaraghavan
- Neuroscience Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, Australia
| | - Brent Neumann
- Neuroscience Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, Australia
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23
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Cho I, Song HO, Cho JH. Mitochondrial Uncoupling Attenuates Age-Dependent Neurodegeneration in C. elegans. Mol Cells 2017; 40:864-870. [PMID: 29081084 PMCID: PMC5712516 DOI: 10.14348/molcells.2017.0172] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 09/08/2017] [Accepted: 09/21/2017] [Indexed: 12/19/2022] Open
Abstract
The uncoupling protein 4 (ucp-4) gene is involved in age-dependent neurodegeneration in C. elegans. Therefore, we aimed to investigate the mechanism underlying the association between mitochondrial uncoupling and neurodegeneration by examining the effects of uncoupling agents and ucp-4 overexpression in C. elegans. Treatment with either DNP or CCCP improved neuronal defects in wild type during aging. Uncoupling agents also restored neuronal phenotypes of ucp-4 mutants to those exhibited by wild type, while ucp-4 overexpression attenuated the severity of age-dependent neurodegeneration. Neuronal improvements were further associated with reductions in mitochondrial membrane potentials. However, these age-dependent neuroprotective effects were limited in mitophagy-deficient mutant, pink-1, background. These results suggest that membrane uncoupling can attenuate age-dependent neurodegeneration by stimulating mitophagy.
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Affiliation(s)
- Injeong Cho
- Department of Biology Education, College of Education, Chosun University, Gwangju 61452,
Korea
| | - Hyun-Ok Song
- Department of Infection Biology, Wonkwang University School of Medicine, Iksan 54538,
Korea
| | - Jeong Hoon Cho
- Department of Biology Education, College of Education, Chosun University, Gwangju 61452,
Korea
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24
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Cho I, Hwang GJ, Cho JH. Uncoupling Protein, UCP-4 May Be Involved in Neuronal Defects During Aging and Resistance to Pathogens in Caenorhabditis elegans. Mol Cells 2016; 39:680-6. [PMID: 27646689 PMCID: PMC5050532 DOI: 10.14348/molcells.2016.0125] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 07/19/2016] [Accepted: 08/01/2016] [Indexed: 11/27/2022] Open
Abstract
Uncoupling proteins (UCPs) are mitochondrial inner membrane proteins that function to dissipate proton motive force and mitochondrial membrane potential. One UCP has been identified in Caenorhabditis elegans (C. elegans), namely UCP-4. In this study, we examined its expression and localization using a GFP marker in C. elegans. ucp-4 was expressed throughout the body from early embryo to aged adult and UCP-4 was localized in the mitochondria. It is known that increased mitochondrial membrane protential leads to a reactive oxygen species (ROS) increase, which is associated with age-related diseases, including neurodegenerative diseases in humans. A ucp-4 mutant showed increased mitochondrial membrane protential in association with increased neuronal defects during aging, and the neurons of ucp-4 overexpressing animals showed decreased neuronal defects during aging. These results suggest that UCP-4 may be involved in neuroprotection during aging via relieving mitochondrial membrane protential. We also investigated the relationship between UCP-4 and innate immunity because increased ROS can affect innate immunity. ucp-4 mutant displayed increased resistance to the pathogen Staphylococcus aureus compared to wild type. The enhanced immunity in the ucp-4 mutant could be related to increased mitochondrial membrane protential, presumably followed by increased ROS. In summary, UCP-4 might have an important role in neuronal aging and innate immune responses through mediating mitochondrial membrane protential.
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Affiliation(s)
- Injeong Cho
- Department of Biology Education, College of Education, Chosun University, Gwangju 61452,
Korea
| | - Gyu Jin Hwang
- Department of Biology Education, College of Education, Chosun University, Gwangju 61452,
Korea
| | - Jeong Hoon Cho
- Department of Biology Education, College of Education, Chosun University, Gwangju 61452,
Korea
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25
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Cho I, Hwang GJ, Cho JH. pxn-1 and pxn-2 May Interact Negatively during Neuronal Development and Aging in C. elegans. Mol Cells 2015; 38:729-33. [PMID: 26194821 PMCID: PMC4546945 DOI: 10.14348/molcells.2015.0124] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 06/04/2015] [Accepted: 06/08/2015] [Indexed: 01/01/2023] Open
Abstract
C. elegans has two functional peroxidasins (PXN), PXN-1 and PXN-2. PXN-2 is essential to consolidate the extracellular matrix during development and is suggested to interact with PXN-1 antagonistically. pxn-1 is involved in neuronal development and possibly maintenance; therefore, we investigated the relationship between pxn-1 and pxn-2 in neuronal development and in aging. During neuronal development, defects caused by pxn-1 overexpression were suppressed by overexpression of both pxn-1 and pxn-2. In neuronal aging process, pxn-1 mutants showed less age-related neuronal defects, such as neuronal outgrowth, neuronal wavy processes, and enhanced short-term memory performance. In addition, pxn-2 overexpressing animals retained an intact neuronal morphology when compared with age-matched controls. Consistent with these results, overexpression of both pxn-1 and pxn-2 restored the severe neuronal defects present with pxn-1 overexpression. These results implied that there is a negative relationship between pxn-1 and pxn-2 via pxn-1 regulating pxn-2. Therefore, pxn-1 may function in neuronal development and age-related neuronal maintenance through pxn-2.
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Affiliation(s)
- Injeong Cho
- Department of Biology Education, College of Education, Chosun University, Gwangju 501-759, Korea
| | - Gyu Jin Hwang
- Department of Biology Education, College of Education, Chosun University, Gwangju 501-759, Korea
| | - Jeong Hoon Cho
- Department of Biology Education, College of Education, Chosun University, Gwangju 501-759, Korea
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26
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Neural activity and CaMKII protect mitochondria from fragmentation in aging Caenorhabditis elegans neurons. Proc Natl Acad Sci U S A 2015; 112:8768-73. [PMID: 26124107 DOI: 10.1073/pnas.1501831112] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Decline in mitochondrial morphology and function is a hallmark of neuronal aging. Here we report that progressive mitochondrial fragmentation is a common manifestation of aging Caenorhabditis elegans neurons and body wall muscles. We show that sensory-evoked activity was essential for maintaining neuronal mitochondrial morphology, and this activity-dependent mechanism required the Degenerin/ENaC sodium channel MEC-4, the L-type voltage-gated calcium channel EGL-19, and the Ca/calmodulin-dependent kinase II (CaMKII) UNC-43. Importantly, UNC-43 phosphorylated and inhibited the dynamin-related protein (DRP)-1, which was responsible for excessive mitochondrial fragmentation in neurons that lacked sensory-evoked activity. Moreover, enhanced activity in the aged neurons ameliorated mitochondrial fragmentation. These findings provide a detailed description of mitochondrial behavior in aging neurons and identify activity-dependent DRP-1 phosphorylation by CaMKII as a key mechanism in neuronal mitochondrial maintenance.
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27
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Murakami S, Halperin AS. Alzheimer's patient feedback to complement research using model systems for cognitive aging and dementia. Front Genet 2014; 5:269. [PMID: 25147560 PMCID: PMC4123719 DOI: 10.3389/fgene.2014.00269] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2014] [Accepted: 07/21/2014] [Indexed: 11/13/2022] Open
Affiliation(s)
- Shin Murakami
- Department of Basic Sciences, College of Osteopathic Medicine, Touro University-California Vallejo, CA, USA
| | - Alexander Sandy Halperin
- Early-Stage Advisory Group/Alumnus (2012-2013), National Alzheimer's Association Chicago, IL, USA ; Alzheimer's Project, Inc. Tallahassee, FL, USA
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28
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Michel M, Lyons LC. Unraveling the complexities of circadian and sleep interactions with memory formation through invertebrate research. Front Syst Neurosci 2014; 8:133. [PMID: 25136297 PMCID: PMC4120776 DOI: 10.3389/fnsys.2014.00133] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 07/07/2014] [Indexed: 12/14/2022] Open
Abstract
Across phylogeny, the endogenous biological clock has been recognized as providing adaptive advantages to organisms through coordination of physiological and behavioral processes. Recent research has emphasized the role of circadian modulation of memory in generating peaks and troughs in cognitive performance. The circadian clock along with homeostatic processes also regulates sleep, which itself impacts the formation and consolidation of memory. Thus, the circadian clock, sleep and memory form a triad with ongoing dynamic interactions. With technological advances and the development of a global 24/7 society, understanding the mechanisms underlying these connections becomes pivotal for development of therapeutic treatments for memory disorders and to address issues in cognitive performance arising from non-traditional work schedules. Invertebrate models, such as Drosophila melanogaster and the mollusks Aplysia and Lymnaea, have proven invaluable tools for identification of highly conserved molecular processes in memory. Recent research from invertebrate systems has outlined the influence of sleep and the circadian clock upon synaptic plasticity. In this review, we discuss the effects of the circadian clock and sleep on memory formation in invertebrates drawing attention to the potential of in vivo and in vitro approaches that harness the power of simple invertebrate systems to correlate individual cellular processes with complex behaviors. In conclusion, this review highlights how studies in invertebrates with relatively simple nervous systems can provide mechanistic insights into corresponding behaviors in higher organisms and can be used to outline possible therapeutic options to guide further targeted inquiry.
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Affiliation(s)
- Maximilian Michel
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine Nashville, TN, USA
| | - Lisa C Lyons
- Department of Biological Science, Program in Neuroscience, Florida State University Tallahassee, FL, USA
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Gkikas I, Petratou D, Tavernarakis N. Longevity pathways and memory aging. Front Genet 2014; 5:155. [PMID: 24926313 PMCID: PMC4044971 DOI: 10.3389/fgene.2014.00155] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 05/10/2014] [Indexed: 12/28/2022] Open
Abstract
The aging process has been associated with numerous pathologies at the cellular, tissue, and organ level. Decline or loss of brain functions, including learning and memory, is one of the most devastating and feared aspects of aging. Learning and memory are fundamental processes by which animals adjust to environmental changes, evaluate various sensory signals based on context and experience, and make decisions to generate adaptive behaviors. Age-related memory impairment is an important phenotype of brain aging. Understanding the molecular mechanisms underlying age-related memory impairment is crucial for the development of therapeutic strategies that may eventually lead to the development of drugs to combat memory loss. Studies in invertebrate animal models have taught us much about the physiology of aging and its effects on learning and memory. In this review we survey recent progress relevant to conserved molecular pathways implicated in both aging and memory formation and consolidation.
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Affiliation(s)
- Ilias Gkikas
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion Crete, Greece
| | - Dionysia Petratou
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion Crete, Greece
| | - Nektarios Tavernarakis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion Crete, Greece ; Department of Basic Sciences, Faculty of Medicine, University of Crete, Heraklion Crete, Greece
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