1
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Koch S, Kandimalla P, Padilla E, Kaur S, Kaur R, Nguyen M, Nelson A, Khalsa S, Younossi-Hartenstein A, Hartenstein V. Structural changes shaping the Drosophila ellipsoid body ER-neurons during development and aging. Dev Biol 2024; 516:96-113. [PMID: 39089472 DOI: 10.1016/j.ydbio.2024.07.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Revised: 07/25/2024] [Accepted: 07/29/2024] [Indexed: 08/04/2024]
Abstract
The ellipsoid body (EB) of the insect brain performs pivotal functions in controlling navigation. Input and output of the EB is provided by multiple classes of R-neurons (now referred to as ER-neurons) and columnar neurons which interact with each other in a stereotypical and spatially highly ordered manner. The developmental mechanisms that control the connectivity and topography of EB neurons are largely unknown. One indispensable prerequisite to unravel these mechanisms is to document in detail the sequence of events that shape EB neurons during their development. In this study, we analyzed the development of the Drosophila EB. In addition to globally following the ER-neuron and columnar neuron (sub)classes in the spatial context of their changing environment we performed a single cell analysis using the multi-color flip out (MCFO) system to analyze the developmental trajectory of ER-neurons at different pupal stages, young adults (4d) and aged adults (∼60d). We show that the EB develops as a merger of two distinct elements, a posterior and anterior EB primordium (prEBp and prEBa, respectively. ER-neurons belonging to different subclasses form growth cones and filopodia that associate with the prEBp and prEBa in a pattern that, from early pupal stages onward, foreshadows their mature structure. Filopodia of all ER-subclasses are initially much longer than the dendritic and terminal axonal branches they give rise to, and are pruned back during late pupal stages. Interestingly, extraneous branches, particularly significant in the dendritic domain, are a hallmark of ER-neuron structure in aged brains. Aging is also associated with a decline in synaptic connectivity from columnar neurons, as well as upregulation of presynaptic protein (Brp) in ER-neurons. Our findings advance the EB (and ER-neurons) as a favorable system to visualize and quantify the development and age-related decline of a complex neuronal circuitry.
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Affiliation(s)
- Sandra Koch
- Department of Molecular Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Pratyush Kandimalla
- Department of Molecular Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA, 90095, USA; Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Eddie Padilla
- Department of Molecular Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Sabrina Kaur
- Department of Molecular Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Rabina Kaur
- Department of Molecular Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - My Nguyen
- Department of Molecular Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Annie Nelson
- Department of Molecular Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Satkartar Khalsa
- Department of Molecular Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Amelia Younossi-Hartenstein
- Department of Molecular Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Volker Hartenstein
- Department of Molecular Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA, 90095, USA.
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2
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Yarmey VR, San-Miguel A. Biomarkers for aging in Caenorhabditis elegans high throughput screening. Biochem Soc Trans 2024; 52:1405-1418. [PMID: 38884801 DOI: 10.1042/bst20231303] [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: 02/27/2024] [Revised: 05/16/2024] [Accepted: 05/28/2024] [Indexed: 06/18/2024]
Abstract
Aging is characterized by a functional decline in organism fitness over time due to a complex combination of genetic and environmental factors [ 1-4]. With an increasing elderly population at risk of age-associated diseases, there is a pressing need for research dedicated to promoting health and longevity through anti-aging interventions. The roundworm Caenorhabditis elegans is an established model organism for aging studies due to its short life cycle, ease of culture, and conserved aging pathways. These benefits also make the worm well-suited for high-throughput screening (HTS) methods to study biomarkers of the molecular changes, cellular dysfunction, and physiological decline associated with aging. Within this review, we offer a summary of recent advances in HTS techniques to study biomarkers of aging in C. elegans.
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Affiliation(s)
- Victoria R Yarmey
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27603, U.S.A
| | - Adriana San-Miguel
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27603, U.S.A
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3
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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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4
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Wirak GS, Florman J, Alkema MJ, Connor CW, Gabel CV. Age-associated changes to neuronal dynamics involve a disruption of excitatory/inhibitory balance in C. elegans. eLife 2022; 11:72135. [PMID: 35703498 PMCID: PMC9273219 DOI: 10.7554/elife.72135] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 06/14/2022] [Indexed: 11/13/2022] Open
Abstract
In the aging brain, many of the alterations underlying cognitive and behavioral decline remain opaque. C. elegans offers a powerful model for aging research, with a simple, well-studied nervous system to further our understanding of the cellular modifications and functional alterations accompanying senescence. We perform multi-neuronal functional imaging across the aged C. elegans nervous system, measuring an age-associated breakdown in system-wide functional organization. At single-cell resolution, we detect shifts in activity dynamics toward higher frequencies. In addition, we measure a specific loss of inhibitory signaling that occurs early in the aging process and alters the systems critical excitatory/inhibitory balance. These effects are recapitulated with mutation of the calcium channel subunit UNC-2/CaV2a. We find that manipulation of inhibitory GABA signaling can partially ameliorate or accelerate the effects of aging. The effects of aging are also partially mitigated by disruption of the insulin signaling pathway, known to increase longevity, or by a reduction of caspase activation. Data from mammals are consistent with our findings, suggesting a conserved shift in the balance of excitatory/inhibitory signaling with age that leads to breakdown in global neuronal dynamics and functional decline.
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Affiliation(s)
- Gregory S Wirak
- Department of Physiology and Biophysics, Boston University, Boston, United States
| | - Jeremy Florman
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, United States
| | - Mark J Alkema
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, United States
| | - Christopher W Connor
- Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Boston, United States
| | - Christopher V Gabel
- Department of Physiology and Biophysics, Boston University, Boston, United States
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5
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Fisher RS, Jimenez RM, Soto E, Kalev D, Elbaum-Garfinkle S. An apparent core/shell architecture of polyQ aggregates in the aging Caenorhabditis elegans neuron. Protein Sci 2021; 30:1482-1486. [PMID: 33966305 DOI: 10.1002/pro.4105] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 05/06/2021] [Accepted: 05/07/2021] [Indexed: 01/28/2023]
Abstract
Huntington's disease is caused by a polyglutamine (polyQ) expansion in the huntingtin protein which results in its abnormal aggregation in the nervous system. Huntingtin aggregates are linked to toxicity and neuronal dysfunction, but a comprehensive understanding of the aggregation mechanism in vivo remains elusive. Here, we examine the morphology of polyQ aggregates in Caenorhabditis elegans mechanosensory neurons as a function of age using confocal and fluorescence lifetime imaging microscopy. We find that aggregates in young worms are mostly spherical with homogenous intensity, but as the worm ages aggregates become substantially more heterogeneous. Most prominently, in older worms we observe an apparent core/shell morphology of polyQ assemblies with decreased intensity in the center. The fluorescence lifetime of polyQ is uniform across the aggregate indicating that the dimmed intensity in the assembly center is most likely not due to quenching or changes in local environment, but rather to displacement of fluorescent polyQ from the central region. This apparent core/shell architecture of polyQ aggregates in aging C. elegans neurons contributes to the diverse landscape of polyQ aggregation states implicated in Huntington's disease.
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Affiliation(s)
- Rachel S Fisher
- Structural Biology Initiative, CUNY Advanced Science Research Center, New York, New York, USA
| | - Rosa Meyo Jimenez
- Structural Biology Initiative, CUNY Advanced Science Research Center, New York, New York, USA
| | - Elizabeth Soto
- Structural Biology Initiative, CUNY Advanced Science Research Center, New York, New York, USA
| | - Darin Kalev
- Structural Biology Initiative, CUNY Advanced Science Research Center, New York, New York, USA
| | - Shana Elbaum-Garfinkle
- Structural Biology Initiative, CUNY Advanced Science Research Center, New York, New York, USA.,Ph.D. Programs in Biochemistry and Biology, The Graduate Center, CUNY, New York, New York, USA
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6
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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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7
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Swim exercise in Caenorhabditis elegans extends neuromuscular and gut healthspan, enhances learning ability, and protects against neurodegeneration. Proc Natl Acad Sci U S A 2019; 116:23829-23839. [PMID: 31685639 PMCID: PMC6876156 DOI: 10.1073/pnas.1909210116] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Exercise is a powerful antiaging intervention that protects against cardiovascular disease, dementia, diabetes, sarcopenia, and cancer. How exercise promotes health benefits to multiple tissues in the body, however, remains poorly understood. We establish a young adult swim exercise regimen for the short-lived nematode Caenorhabditis elegans that induces health benefits at the neuromuscular, intestinal, and cognitive levels and protects against neurodegeneration in models of tauopathy, Alzheimer’s disease, and Huntington’s disease. Importantly, we found that swim exercise performed exclusively in early adulthood promotes long-lasting systemic benefits that are still detectable in midlife. The advantages of C. elegans as a short-lived genetic model will allow for dissection of the molecular circuitry involved in system-wide exercise benefits. Regular physical exercise is the most efficient and accessible intervention known to promote healthy aging in humans. The molecular and cellular mechanisms that mediate system-wide exercise benefits, however, remain poorly understood, especially as applies to tissues that do not participate directly in training activity. The establishment of exercise protocols for short-lived genetic models will be critical for deciphering fundamental mechanisms of transtissue exercise benefits to healthy aging. Here we document optimization of a long-term swim exercise protocol for Caenorhabditis elegans and we demonstrate its benefits to diverse aging tissues, even if exercise occurs only during a restricted phase of adulthood. We found that multiple daily swim sessions are essential for exercise adaptation, leading to body wall muscle improvements in structural gene expression, locomotory performance, and mitochondrial morphology. Swim exercise training enhances whole-animal health parameters, such as mitochondrial respiration and midlife survival, increases functional healthspan of the pharynx and intestine, and enhances nervous system health by increasing learning ability and protecting against neurodegeneration in models of tauopathy, Alzheimer’s disease, and Huntington’s disease. Remarkably, swim training only during early adulthood induces long-lasting systemic benefits that in several cases are still detectable well into midlife. Our data reveal the broad impact of swim exercise in promoting extended healthspan of multiple C. elegans tissues, underscore the potency of early exercise experience to influence long-term health, and establish the foundation for exploiting the powerful advantages of this genetic model for the dissection of the exercise-dependent molecular circuitry that confers system-wide health benefits to aging adults.
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8
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Ly S, Naidoo N. Loss of DmGluRA exacerbates age-related sleep disruption and reduces lifespan. Neurobiol Aging 2019; 80:83-90. [PMID: 31103635 DOI: 10.1016/j.neurobiolaging.2019.04.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 04/03/2019] [Accepted: 04/05/2019] [Indexed: 11/26/2022]
Abstract
Declines in sleep amount and quality-characterized by excessive daytime sleepiness and an inability to sleep at night-are common features of aging. Sleep dysfunction is also associated with age-related ailments and diseases, suggesting that sleep is functionally relevant to the aging process. Metabotropic glutamate receptors (mGluRs)-which are critical regulators of neurotransmission and synaptic plasticity-have been implicated in both age-related disease and sleep regulation. Therefore, in this study, we examined the sleep and aging effect of complete genetic loss of mGluR signaling in Drosophila melanogaster. Genetic knockdown of the sole Drosophila mGluR-known as DmGluRA-reduced daytime wakefulness and nighttime sleep, recapitulating age-related sleep changes that occur across species. Furthermore, loss of DmGluRA significantly reduced lifespan and exacerbated age-related sleep loss in older flies. Thus, we identify DmGluRA as a novel regulator of sleep whose loss results in an age-relevant sleep phenotype that is associated with shortened lifespan. This is the first evidence that mGluR signaling regulates sleep/wake in a manner that is relevant to the aging process.
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Affiliation(s)
- Sarah Ly
- Center for Sleep and Circadian Neurobiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Nirinjini Naidoo
- Center for Sleep and Circadian Neurobiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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9
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Hunter S, Maulik M, Scerbak C, Vayndorf E, Taylor BE. Caenorhabditis Sieve: A Low-tech Instrument and Methodology for Sorting Small Multicellular Organisms. J Vis Exp 2018. [PMID: 30035770 DOI: 10.3791/58014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Caenorhabditis elegans (C. elegans) is a well-established model organism used across a range of basic and biomedical research. Within the nematode research community, there is a need for an affordable and effective way to maintain large, age-matched populations of C. elegans. Here, we present a methodology for mechanically sorting and cleaning C. elegans. Our aim is to provide a cost-effective, efficient, fast, and simple process to obtain animals of uniform sizes and life stages for their use in experiments. This tool, the Caenorhabditis Sieve, uses a custom-built lid system that threads onto common conical lab tubes and sorts C. elegans based on body size. We also demonstrate that the Caenorhabditis Sieve effectively transfers animals from one culture plate to another allowing for a rapid sorting, synchronizing, and cleaning without impacting markers of health, including motility and stress-inducible gene reporters. This accessible and innovative tool is a fast, efficient, and non-stressful option for maintaining C. elegans populations.
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Affiliation(s)
- Skyler Hunter
- Department of Biology and Wildlife, University of Alaska Fairbanks; Institute of Arctic Biology, University of Alaska Fairbanks
| | - Malabika Maulik
- Department of Chemistry and Biochemistry, University of Alaska Fairbanks;
| | | | - Elena Vayndorf
- Institute of Arctic Biology, University of Alaska Fairbanks
| | - Barbara E Taylor
- Department of Biological Sciences, College of Natural Science and Mathematics, California State University Long Beach
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10
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Scerbak C, Vayndorf E, Hernandez A, McGill C, Taylor B. Lowbush cranberry acts through DAF-16/FOXO signaling to promote increased lifespan and axon branching in aging posterior touch receptor neurons. GeroScience 2018; 40:151-162. [PMID: 29717416 PMCID: PMC5964060 DOI: 10.1007/s11357-018-0016-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 04/09/2018] [Indexed: 11/24/2022] Open
Abstract
Medicinal berries are appreciated for their health benefits, in traditional ecological knowledge and nutrition science. Determining the cellular mechanisms underlying the effects of berry supplementation may contribute to our understanding of aging. Here, we report that lowbush cranberry (Vaccinium vitis-idaea) treatment causes marked nuclear localization of the central aging-related transcription factor DAF-16/FOXO in aged Caenorhabditis elegans. Further, functional DAF-16 is required for the lifespan extension, improved mechanosensation, and posterior touch receptor neuron morphological changes induced by lowbush cranberry treatments. DAF-16 is not observed in nuceli nor required for lifespan extension in lifespan-extending Alaskan blueberry treatments and, while DAF-16 is not visibly induced into the nucleus in lifespan-extending Alaskan chaga treatments, it is required for chaga-induced lifespan extension. These findings underscore the importance of DAF-16 in the aging of whole organisms and touch receptor neurons and also, importantly, indicate that this critical pathway is not always activated upon consumption of functional foods that impact aging.
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Affiliation(s)
- Courtney Scerbak
- Biology and Chemistry Departments, Earlham College, 801 National Road West, Richmond, IN, USA.
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, USA.
- Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, AK, USA.
| | - Elena Vayndorf
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - Alicia Hernandez
- Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - Colin McGill
- Chemistry Department, University of Alaska Anchorage, Anchorage, AK, USA
| | - Barbara Taylor
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, USA
- Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, AK, USA
- Department of Biological Sciences, California State University, Long Beach, CA, USA
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11
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De Stasio EA, Mueller KP, Bauer RJ, Hurlburt AJ, Bice SA, Scholtz SL, Phirke P, Sugiaman-Trapman D, Stinson LA, Olson HB, Vogel SL, Ek-Vazquez Z, Esemen Y, Korzynski J, Wolfe K, Arbuckle BN, Zhang H, Lombard-Knapp G, Piasecki BP, Swoboda P. An Expanded Role for the RFX Transcription Factor DAF-19, with Dual Functions in Ciliated and Nonciliated Neurons. Genetics 2018; 208:1083-1097. [PMID: 29301909 PMCID: PMC5844324 DOI: 10.1534/genetics.117.300571] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 01/02/2017] [Indexed: 02/06/2023] Open
Abstract
Regulatory Factor X (RFX) transcription factors (TFs) are best known for activating genes required for ciliogenesis in both vertebrates and invertebrates. In humans, eight RFX TFs have a variety of tissue-specific functions, while in the worm Caenorhabditis elegans, the sole RFX gene, daf-19, encodes a set of nested isoforms. Null alleles of daf-19 confer pleiotropic effects including altered development with a dauer constitutive phenotype, complete absence of cilia and ciliary proteins, and defects in synaptic protein maintenance. We sought to identify RFX/daf-19 target genes associated with neuronal functions other than ciliogenesis using comparative transcriptome analyses at different life stages of the worm. Subsequent characterization of gene expression patterns revealed one set of genes activated in the presence of DAF-19 in ciliated sensory neurons, whose activation requires the daf-19c isoform, also required for ciliogenesis. A second set of genes is downregulated in the presence of DAF-19, primarily in nonsensory neurons. The human orthologs of some of these neuronal genes are associated with human diseases. We report the novel finding that daf-19a is directly or indirectly responsible for downregulation of these neuronal genes in C. elegans by characterizing a new mutation affecting the daf-19a isoform (tm5562) and not associated with ciliogenesis, but which confers synaptic and behavioral defects. Thus, we have identified a new regulatory role for RFX TFs in the nervous system. The new daf-19 candidate target genes we have identified by transcriptomics will serve to uncover the molecular underpinnings of the pleiotropic effects that daf-19 exerts on nervous system function.
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Affiliation(s)
| | | | - Rosemary J Bauer
- Department of Biology, Lawrence University, Appleton, Wisconsin 54911
| | | | - Sophie A Bice
- Department of Biology, Lawrence University, Appleton, Wisconsin 54911
| | - Sophie L Scholtz
- Department of Biology, Lawrence University, Appleton, Wisconsin 54911
| | - Prasad Phirke
- Department of Biosciences and Nutrition, Karolinska Institute, 141 83 Huddinge, Sweden
| | | | - Loraina A Stinson
- Department of Biology, Lawrence University, Appleton, Wisconsin 54911
| | - Haili B Olson
- Department of Biology, Lawrence University, Appleton, Wisconsin 54911
| | - Savannah L Vogel
- Department of Biology, Lawrence University, Appleton, Wisconsin 54911
| | | | - Yagmur Esemen
- Department of Biology, Lawrence University, Appleton, Wisconsin 54911
| | - Jessica Korzynski
- Department of Biology, Lawrence University, Appleton, Wisconsin 54911
| | - Kelsey Wolfe
- Department of Biology, Lawrence University, Appleton, Wisconsin 54911
| | - Bonnie N Arbuckle
- Department of Biology, Lawrence University, Appleton, Wisconsin 54911
| | - He Zhang
- Department of Biology, Lawrence University, Appleton, Wisconsin 54911
| | | | - Brian P Piasecki
- Department of Biology, Lawrence University, Appleton, Wisconsin 54911
| | - Peter Swoboda
- Department of Biosciences and Nutrition, Karolinska Institute, 141 83 Huddinge, Sweden
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12
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Chongtham A, Barbaro B, Filip T, Syed A, Huang W, Smith MR, Marsh JL. Nonmammalian Models of Huntington's Disease. Methods Mol Biol 2018; 1780:75-96. [PMID: 29856015 DOI: 10.1007/978-1-4939-7825-0_5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Flies, worms, yeast and more recently zebra fish have all been engineered to express expanded polyglutamine repeat versions of Huntingtin with various resulting pathologies including early death, neurodegeneration, and loss of motor function. Each of these models present particular features that make it useful in studying the mechanisms of polyglutamine pathology. However, one particular unbiased readout of mHTT pathology is functional loss of motor control. Loss of motor control is prominent in patients, but it remains unresolved whether pathogenic symptoms in patients result from overt degeneration and loss of neurons or from malfunctioning of surviving neurons as the pathogenic insult builds up. This is why a functional assay such as motor control can be uniquely powerful in revealing early as well as late neurological deficits and does not rely on assumptions such as that the level of inclusions or the degree of neuronal loss can be equated with the level of pathology. Drosophila is well suited for such assays because it contains a functioning nervous system with many parallels to the human condition. In addition, the ability to readily express mHTT transgenes in different tissues and subsets of neurons allows one the possibility of isolating a particular effect to a subset of neurons where one can correlate subcellular events in response to mHTT challenge with pathology at both the cellular and organismal levels. Here we describe methods to monitor the degree of motor function disruption in Drosophila models of HD and we include a brief summary of other nonmammalian models of HD and discussion of their unique strengths.
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Affiliation(s)
- Anjalika Chongtham
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, 92697, CA, USA
| | - Brett Barbaro
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, 92697, CA, USA.,The Scripps Research Institute, La Jolla, CA, USA
| | - Tomas Filip
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, 92697, CA, USA.,Biology Centre Czech Acad. Sci., Ceske Budejovice, Czech Republic
| | - Adeela Syed
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, 92697, CA, USA
| | - Weijian Huang
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, 92697, CA, USA
| | - Marianne R Smith
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, 92697, CA, USA.,University Advancement, UC Irvine, Irvine, CA, USA
| | - J Lawrence Marsh
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, 92697, CA, USA.
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Van Assche R, Borghgraef C, Vaneyck J, Dumoulin M, Schoofs L, Temmerman L. In vitro aggregating β-lactamase-polyQ chimeras do not induce toxic effects in an in vivo Caenorhabditis elegans model. J Negat Results Biomed 2017; 16:14. [PMID: 28830560 PMCID: PMC5568214 DOI: 10.1186/s12952-017-0080-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 08/14/2017] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND A series of human diseases are caused by the misfolding and aggregation of specific proteins or peptides into amyloid fibrils; nine of these diseases, referred to as polyglutamine diseases, are associated with proteins carrying an expanded polyglutamine (polyQ) region. While the presence of this latter is thought to be the determinant factor for the development of polyQ diseases, the non-polyQ regions of the host proteins are thought to play a significant modulating role. METHOD In order to better understand the role of non-polyQ regions, the toxic effects of model proteins bearing different polyQ regions (containing up to 79 residues) embedded at two distinct locations within the β-lactamase (BlaP) host enzyme were evaluated in Caenorhabditis elegans. This small organism can be advantageous for the validation of in vitro findings, as it provides a multicellular context yet avoids the typical complexity of common studies relying on vertebrate models. Several phenotypic assays were performed in order to screen for potential toxic effects of the different BlaP-polyQ proteins. RESULTS Despite the significant in vitro aggregation of BlaP-polyQ proteins with long polyQ regions, none of the BlaP-polyQ chimeras aggregated in the generated transgenic in vivo models. CONCLUSION The absence of a toxic effect of the expression of BlaP-polyQ chimeras may find its cause in biochemical mechanisms present in vivo to cope with protein aggregation (e.g. presence of chaperones) or in C. elegans' limitations such as its short lifespan. It is plausible that the aggregation propensities of the different BlaP chimeras containing embedded polyQ sequences are too low in this in vivo environment to permit their aggregation. These experiments emphasize the need for several comparative and in vivo verification studies of biologically relevant in vitro findings, which reveal both the strengths and limitations of widely used model systems.
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Affiliation(s)
- Roel Van Assche
- Animal Physiology and Neurobiology, Department of Biology, KU Leuven (University of Leuven), Zoological Institute, Naamsestraat 59, 3000 Leuven, Belgium
| | - Charline Borghgraef
- Animal Physiology and Neurobiology, Department of Biology, KU Leuven (University of Leuven), Zoological Institute, Naamsestraat 59, 3000 Leuven, Belgium
| | - Jonathan Vaneyck
- Enzymology and Protein Folding, Center for Protein Engineering, InBioS, Institute of Chemistry, University of Liège, Sart-Tilman, 4000 Liège, Belgium
| | - Mireille Dumoulin
- Enzymology and Protein Folding, Center for Protein Engineering, InBioS, Institute of Chemistry, University of Liège, Sart-Tilman, 4000 Liège, Belgium
| | - Liliane Schoofs
- Animal Physiology and Neurobiology, Department of Biology, KU Leuven (University of Leuven), Zoological Institute, Naamsestraat 59, 3000 Leuven, Belgium
| | - Liesbet Temmerman
- Animal Physiology and Neurobiology, Department of Biology, KU Leuven (University of Leuven), Zoological Institute, Naamsestraat 59, 3000 Leuven, Belgium
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Maulik M, Mitra S, Bult-Ito A, Taylor BE, Vayndorf EM. Behavioral Phenotyping and Pathological Indicators of Parkinson's Disease in C. elegans Models. Front Genet 2017; 8:77. [PMID: 28659967 PMCID: PMC5468440 DOI: 10.3389/fgene.2017.00077] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 05/22/2017] [Indexed: 12/14/2022] Open
Abstract
Parkinson's disease (PD) is a neurodegenerative disorder with symptoms that progressively worsen with age. Pathologically, PD is characterized by the aggregation of α-synuclein in cells of the substantia nigra in the brain and loss of dopaminergic neurons. This pathology is associated with impaired movement and reduced cognitive function. The etiology of PD can be attributed to a combination of environmental and genetic factors. A popular animal model, the nematode roundworm Caenorhabditis elegans, has been frequently used to study the role of genetic and environmental factors in the molecular pathology and behavioral phenotypes associated with PD. The current review summarizes cellular markers and behavioral phenotypes in transgenic and toxin-induced PD models of C. elegans.
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Affiliation(s)
- Malabika Maulik
- Department of Chemistry and Biochemistry, University of Alaska FairbanksFairbanks, AK, United States
| | - Swarup Mitra
- Department of Chemistry and Biochemistry, University of Alaska FairbanksFairbanks, AK, United States
| | - Abel Bult-Ito
- Department of Biology and Wildlife, University of Alaska FairbanksFairbanks, AK, United States
| | - Barbara E Taylor
- Department of Biological Sciences, California State University, Long BeachLong Beach, CA, United States
| | - Elena M Vayndorf
- Institute of Arctic Biology, University of Alaska FairbanksFairbanks, AK, United States
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C. elegans neurons jettison protein aggregates and mitochondria under neurotoxic stress. Nature 2017; 542:367-371. [PMID: 28178240 PMCID: PMC5336134 DOI: 10.1038/nature21362] [Citation(s) in RCA: 250] [Impact Index Per Article: 35.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Accepted: 01/03/2017] [Indexed: 12/12/2022]
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Scerbak C, Vayndorf EM, Hernandez A, McGill C, Taylor BE. Mechanosensory Neuron Aging: Differential Trajectories with Lifespan-Extending Alaskan Berry and Fungal Treatments in Caenorhabditis elegans. Front Aging Neurosci 2016; 8:173. [PMID: 27486399 PMCID: PMC4947587 DOI: 10.3389/fnagi.2016.00173] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 06/28/2016] [Indexed: 01/08/2023] Open
Abstract
Many nutritional interventions that increase lifespan are also proposed to postpone age-related declines in motor and cognitive function. Potential sources of anti-aging compounds are the plants and fungi that have adapted to extreme environments. We studied the effects of four commonly consumed and culturally relevant Interior Alaska berry and fungus species (bog blueberry, lowbush cranberry, crowberry, and chaga) on the decline in overall health and neuron function and changes in touch receptor neuron morphology associated with aging. We observed increased wild-type Caenorhabditis elegans lifespan and improved markers of healthspan upon treatment with Alaskan blueberry, lowbush cranberry, and chaga extracts. Interestingly, although all three treatments increased lifespan, they differentially affected the development of aberrant morphologies in touch receptor neurons. Blueberry treatments decreased anterior mechanosensory neuron (ALM) aberrations (i.e., extended outgrowths and abnormal cell bodies) while lowbush cranberry treatment increased posterior mechanosensory neuron (PLM) aberrations, namely process branching. Chaga treatment both decreased ALM aberrations (i.e., extended outgrowths) and increased PLM aberrations (i.e., process branching and loops). These results support the large body of knowledge positing that there are multiple cellular strategies and mechanisms for promoting health with age. Importantly, these results also demonstrate that although an accumulation of abnormal neuron morphologies is associated with aging and decreased health, not all of these morphologies are detrimental to neuronal and organismal health.
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Affiliation(s)
- Courtney Scerbak
- Institute of Arctic Biology, University of Alaska FairbanksFairbanks, AK, USA
- Department of Biology and Wildlife, University of Alaska FairbanksFairbanks, AK, USA
- Department of Biology, Earlham CollegeRichmond, IN, USA
| | - Elena M. Vayndorf
- Institute of Arctic Biology, University of Alaska FairbanksFairbanks, AK, USA
| | - Alicia Hernandez
- Department of Biology and Wildlife, University of Alaska FairbanksFairbanks, AK, USA
| | - Colin McGill
- Chemistry Department, University of Alaska AnchorageAnchorage, AK, USA
| | - Barbara E. Taylor
- Institute of Arctic Biology, University of Alaska FairbanksFairbanks, AK, USA
- Department of Biology and Wildlife, University of Alaska FairbanksFairbanks, AK, USA
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