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Aprison EZ, Dzitoyeva S, Ruvinsky I. The roles of TGFβ and serotonin signaling in regulating proliferation of oocyte precursors and germline aging. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.08.593208. [PMID: 38766220 PMCID: PMC11100717 DOI: 10.1101/2024.05.08.593208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
The decline of oocyte quality in aging but otherwise relatively healthy individuals compels a search for underlying mechanisms. Building upon a finding that exposure to male pheromone ascr#10 improves oocyte quality in C. elegans, we uncovered a regulatory cascade that promotes proliferation of oocyte precursors in adults and regulates oocyte quality. We found that the male pheromone promotes proliferation of oocyte precursors by upregulating LAG-2, a ligand of the Notch-like pathway in the germline stem cell niche. LAG-2 is upregulated by a TGFβ-like ligand DAF-7 revealing similarity of regulatory mechanisms that promote germline proliferation in adults and larvae. A serotonin circuit that also regulates food search and consumption upregulates DAF-7 specifically in adults. The serotonin/DAF-7 signaling promotes germline expansion to compensate for oocyte expenditure which is increased by the male pheromone. Finally, we show that the earliest events in reproductive aging may be due to declining expression of LAG-2 and DAF-7. Our findings highlight neuronal signals that promote germline proliferation in response to the environment and argue that deteriorating oocyte quality may be due to reduced neuronal expression of key germline regulators.
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Affiliation(s)
- Erin Z. Aprison
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Svetlana Dzitoyeva
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Ilya Ruvinsky
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
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2
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Zhao K, Zhang Y, Liu M, Huang Y, Wang S, An J, Wang Y, Shang Y. The joint effects of nanoplastics and TBBPA on neurodevelopmental toxicity in Caenorhabditis elegans. Toxicol Res (Camb) 2023; 12:76-85. [PMID: 36866216 PMCID: PMC9972810 DOI: 10.1093/toxres/tfac086] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 12/16/2022] [Accepted: 12/20/2022] [Indexed: 01/11/2023] Open
Abstract
Both of nanoplastics (NPs) and Tetrabromobisphenol A (TBBPA) are organic pollutants widely detected in the environment and organisms. The large specific surface area of NPs makes them ideal vectors for carrying various toxicants, such as organic pollutants, metals, or other nanomaterials, posing potential threats to human health. This study used Caenorhabditis elegans (C. elegans) to investigate the neurodevelopmental toxicity induced by combined exposure of TBBPA and polystyrene NPs. Our results showed that combined exposure caused synergistic inhibitory effects on the survival rate, body length/width, and locomotor ability. Furthermore, the overproduction of reactive oxygen species (ROS), lipofuscin accumulation, and dopaminergic neuronal loss suggested that oxidative stress was involved in induction of neurodevelopmental toxicity in C. elegans. The expressions of Parkinson's disease related gene (pink-1) and Alzheimer's disease related gene (hop-1) were significantly increased after combined exposure of TBBPA and polystyrene NPs. Knock out of pink-1 and hop-1 genes alleviated the adverse effects such as growth retardation, locomotion deficits, dopaminergic loss, and oxidative stress induction, indicating that pink-1 and hop-1 genes play an important role in neurodevelopmental toxicity induced by TBBPA and polystyrene NPs. In conclusion, TBBPA and polystyrene NPs had synergistic effect on oxidative stress induction and neurodevelopmental toxicity in C. elegans, which was mediated through increased expressions of pink-1 and hop-1.
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Affiliation(s)
- Kunming Zhao
- School of Environmental and Chemical Engineering, Shanghai University, Nanchen Road 333, Shanghai 200444, China
| | - Ying Zhang
- Department of Neurology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Ganhe Road 110, Shanghai 200080, China
| | - Mingyuan Liu
- Department of Neurology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Ganhe Road 110, Shanghai 200080, China
| | - Yuecheng Huang
- Shanghai Joint Management and Development Center of Medical Affairs and Organizations, Beijing West Road 1477, Shanghai 200040, China
| | - Siyan Wang
- School of Environmental and Chemical Engineering, Shanghai University, Nanchen Road 333, Shanghai 200444, China
| | - Jing An
- School of Environmental and Chemical Engineering, Shanghai University, Nanchen Road 333, Shanghai 200444, China
| | - Yan Wang
- Shanghai Institute of Cerebrovascular Disease, Keyuan Road 1278, Shanghai 201203, China
| | - Yu Shang
- School of Environmental and Chemical Engineering, Shanghai University, Nanchen Road 333, Shanghai 200444, China
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3
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Mechanisms of germ cell survival and plasticity in Caenorhabditis elegans. Biochem Soc Trans 2022; 50:1517-1526. [PMID: 36196981 PMCID: PMC9704514 DOI: 10.1042/bst20220878] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 09/20/2022] [Accepted: 09/21/2022] [Indexed: 11/17/2022]
Abstract
Animals constantly encounter environmental and physiological stressors that threaten survival and fertility. Somatic stress responses and germ cell arrest/repair mechanisms are employed to withstand such challenges. The Caenorhabditis elegans germline combats stress by initiating mitotic germ cell quiescence to preserve genome integrity, and by removing meiotic germ cells to prevent inheritance of damaged DNA or to tolerate lack of germline nutrient supply. Here, we review examples of germline recovery from distinct stressors - acute starvation and defective splicing - where quiescent mitotic germ cells resume proliferation to repopulate a germ line following apoptotic removal of meiotic germ cells. These protective mechanisms reveal the plastic nature of germline stem cells.
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Venzon M, Das R, Luciano DJ, Burnett J, Park HS, Devlin JC, Kool ET, Belasco JG, Hubbard EJA, Cadwell K. Microbial byproducts determine reproductive fitness of free-living and parasitic nematodes. Cell Host Microbe 2022; 30:786-797.e8. [PMID: 35413267 PMCID: PMC9187612 DOI: 10.1016/j.chom.2022.03.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 02/09/2022] [Accepted: 03/10/2022] [Indexed: 11/03/2022]
Abstract
Trichuris nematodes reproduce within the microbiota-rich mammalian intestine and lay thousands of eggs daily, facilitating their sustained presence in the environment and hampering eradication efforts. Here, we show that bacterial byproducts facilitate the reproductive development of nematodes. First, we employed a pipeline using the well-characterized, free-living nematode C. elegans to identify microbial factors with conserved roles in nematode reproduction. A screen for E. coli mutants that impair C. elegans fertility identified genes in fatty acid biosynthesis and ethanolamine utilization pathways, including fabH and eutN. Additionally, Trichuris muris eggs displayed defective hatching in the presence of fabH- or eutN-deficient E. coli due to reduced arginine or elevated aldehydes, respectively. T. muris reared in gnotobiotic mice colonized with these E. coli mutants displayed morphological defects and failed to lay viable eggs. These findings indicate that microbial byproducts mediate evolutionarily conserved transkingdom interactions that impact the reproductive fitness of distantly related nematodes.
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Affiliation(s)
- Mericien Venzon
- Vilcek Institute of Graduate Biomedical Sciences, New York University Grossman School of Medicine, New York, NY 10016, USA; Kimmel Center for Biology and Medicine at the Skirball Institute, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Ritika Das
- Kimmel Center for Biology and Medicine at the Skirball Institute, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Daniel J Luciano
- Kimmel Center for Biology and Medicine at the Skirball Institute, New York University Grossman School of Medicine, New York, NY 10016, USA; Department of Microbiology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Julia Burnett
- Kimmel Center for Biology and Medicine at the Skirball Institute, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Hyun Shin Park
- Seegene Inc., Ogeum-ro, Songpa-Gu, Seoul 05548, Republic of Korea
| | - Joseph Cooper Devlin
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Eric T Kool
- Department of Chemistry, Stanford Cancer Institute, and ChEM-H Institute, Stanford University, Stanford, CA 94305, USA
| | - Joel G Belasco
- Kimmel Center for Biology and Medicine at the Skirball Institute, New York University Grossman School of Medicine, New York, NY 10016, USA; Department of Microbiology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - E Jane Albert Hubbard
- Kimmel Center for Biology and Medicine at the Skirball Institute, New York University Grossman School of Medicine, New York, NY 10016, USA; Department of Cell Biology, New York University Grossman School of Medicine, New York, NY 10016, USA; Department of Pathology, New York University Grossman School of Medicine, New York, NY 10016, USA.
| | - Ken Cadwell
- Kimmel Center for Biology and Medicine at the Skirball Institute, New York University Grossman School of Medicine, New York, NY 10016, USA; Department of Microbiology, New York University Grossman School of Medicine, New York, NY 10016, USA; Division of Gastroenterology, Department of Medicine, New York University Grossman School of Medicine, New York, NY 10016, USA.
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5
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Abstract
Pheromones exchanged by conspecifics are a major class of chemical signals that can alter behavior, physiology, and development. In particular, males and females communicate with potential mating partners via sex pheromones to promote reproductive success. Physiological and developmental mechanisms by which pheromones facilitate progeny production remain largely enigmatic. Here, we describe how a Caenorhabditis elegans male pheromone, ascr#10, improves the oogenic germline. Before most signs of aging become evident, C. elegans hermaphrodites start producing lower-quality gametes characterized by abnormal morphology, increased rates of chromosomal nondisjunction, and higher penetrance of deleterious alleles. We show that exposure to the male pheromone substantially ameliorates these defects and reduces embryonic lethality. ascr#10 stimulates proliferation of germline precursor cells in adult hermaphrodites. Coupled to the greater precursor supply is increased physiological germline cell death, which is required to improve oocyte quality in older mothers. The hermaphrodite germline is sensitive to the pheromone only during a time window, comparable in duration to a larval stage, in early adulthood. During this period, prereproductive adults assess the suitability of the environment for reproduction. Our results identify developmental events that occur in the oogenic germline in response to a male pheromone. They also suggest that the opposite effects of the pheromone on gamete quality and maternal longevity arise from competition over resource allocation between soma and the germline.
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Amar A, Hubbard EJA, Kugler H. Modeling the C. elegans germline stem cell genetic network using automated reasoning. Biosystems 2022; 217:104672. [PMID: 35469833 PMCID: PMC9142837 DOI: 10.1016/j.biosystems.2022.104672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Revised: 03/31/2022] [Accepted: 04/04/2022] [Indexed: 11/18/2022]
Abstract
Computational methods and tools are a powerful complementary approach to experimental work for studying regulatory interactions in living cells and systems. We demonstrate the use of formal reasoning methods as applied to the Caenorhabditis elegans germ line, which is an accessible system for stem cell research. The dynamics of the underlying genetic networks and their potential regulatory interactions are key for understanding mechanisms that control cellular decision-making between stem cells and differentiation. We model the “stem cell fate” versus entry into the “meiotic development” pathway decision circuit in the young adult germ line based on an extensive study of published experimental data and known/hypothesized genetic interactions. We apply a formal reasoning framework to derive predictive networks for control of differentiation. Using this approach we simultaneously specify many possible scenarios and experiments together with potential genetic interactions, and synthesize genetic networks consistent with all encoded experimental observations. In silico analysis of knock-down and overexpression experiments within our model recapitulate published phenotypes of mutant animals and can be applied to make predictions on cellular decision-making. A methodological contribution of this work is demonstrating how to effectively model within a formal reasoning framework a complex genetic network with a wealth of known experimental data and constraints. We provide a summary of the steps we have found useful for the development and analysis of this model and can potentially be applicable to other genetic networks. This work also lays a foundation for developing realistic whole tissue models of the C. elegans germ line where each cell in the model will execute a synthesized genetic network.
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Affiliation(s)
- Ani Amar
- The Faculty of Engineering, Bar-Ilan University, Ramat Gan 5290002, Israel.
| | - E Jane Albert Hubbard
- Skirball Institute of Biomolecular Medicine, Department of Cell Biology, Department of Pathology, NYU Grossman School of Medicine, 540 First Avenue, New York, NY 10016, United States of America.
| | - Hillel Kugler
- The Faculty of Engineering, Bar-Ilan University, Ramat Gan 5290002, Israel.
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Zhang H, Liu T, Song X, Zhou Q, Tang J, Sun Q, Pu Y, Yin L, Zhang J. Study on the reproductive toxicity and mechanism of tri-n-butyl phosphate (TnBP) in Caenorhabditis elegans. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 227:112896. [PMID: 34673412 DOI: 10.1016/j.ecoenv.2021.112896] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 09/30/2021] [Accepted: 10/10/2021] [Indexed: 06/13/2023]
Abstract
Tri-n-butyl phosphate (TnBP), a typical alkyl organophosphate ester is widely used as an emerging flame retardant for polybrominated diphenyl ethers alternatives, but the potential toxicity and mechanism are unclear. In this study, the reproductive toxicity of TnBP and its related mechanisms were explored using the Caenorhabditis elegans (C. elegans) model. After TnBP (100-1000 μg/L) exposure, brood size and the number of fertilized eggs in the uterus in C. elegans were significantly reduced, the relative area of gonad arm and the number of total germline cells in C. elegans were significantly reduced, germ cell apoptosis and germ cell DNA damage in C. elegans were significantly increased, the level of ROS in C. elegans was significantly increased. Furthermore, TnBP exposure caused abnormal gene expressions of cell apoptosis (ced-9, ced-4 and ced-3), DNA damage (hus-1, clk-2, cep-1 and egl-1) and oxidative stress (mev-1 and gas-1). TnBP exposure can lead to reproductive ability decreased and gonad development impaired in C. elegans, the mechanism of TnBP reduced reproductive ability may be related to germ cell apoptosis, germ cell DNA damage and oxidative stress. Environmental exposure to TnBP may have potential reproductive toxicity.
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Affiliation(s)
- Hongdan Zhang
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China
| | - Tongtong Liu
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China
| | - Xuelong Song
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China
| | - Qinyu Zhou
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China
| | - Jielin Tang
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China
| | - Qianyu Sun
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China
| | - Yuepu Pu
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China
| | - Lihong Yin
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China
| | - Juan Zhang
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China.
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8
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Tolkin T, Hubbard EJA. Germline Stem and Progenitor Cell Aging in C. elegans. Front Cell Dev Biol 2021; 9:699671. [PMID: 34307379 PMCID: PMC8297657 DOI: 10.3389/fcell.2021.699671] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 06/07/2021] [Indexed: 11/13/2022] Open
Abstract
Like many animals and humans, reproduction in the nematode C. elegans declines with age. This decline is the cumulative result of age-related changes in several steps of germline function, many of which are highly accessible for experimental investigation in this short-lived model organism. Here we review recent work showing that a very early and major contributing step to reproductive decline is the depletion of the germline stem and progenitor cell pool. Since many cellular and molecular aspects of stem cell biology and aging are conserved across animals, understanding mechanisms of age-related decline of germline stem and progenitor cells in C. elegans has broad implications for aging stem cells, germline stem cells, and reproductive aging.
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Affiliation(s)
- Theadora Tolkin
- Department of Cell Biology, Skirball Institute of Biomolecular Medicine, NYU Grossman School of Medicine, New York, NY, United States
| | - E Jane Albert Hubbard
- Department of Cell Biology, Skirball Institute of Biomolecular Medicine, NYU Grossman School of Medicine, New York, NY, United States
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9
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Mosquera JV, Bacher MC, Priess JR. Nuclear lipid droplets and nuclear damage in Caenorhabditis elegans. PLoS Genet 2021; 17:e1009602. [PMID: 34133414 PMCID: PMC8208577 DOI: 10.1371/journal.pgen.1009602] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 05/14/2021] [Indexed: 01/01/2023] Open
Abstract
Fat stored in the form of lipid droplets has long been considered a defining characteristic of cytoplasm. However, recent studies have shown that nuclear lipid droplets occur in multiple cells and tissues, including in human patients with fatty liver disease. The function(s) of stored fat in the nucleus has not been determined, and it is possible that nuclear fat is beneficial in some situations. Conversely, nuclear lipid droplets might instead be deleterious by disrupting nuclear organization or triggering aggregation of hydrophobic proteins. We show here that nuclear lipid droplets occur normally in C. elegans intestinal cells and germ cells, but appear to be associated with damage only in the intestine. Lipid droplets in intestinal nuclei can be associated with novel bundles of microfilaments (nuclear actin) and membrane tubules that might have roles in damage repair. To increase the normal, low frequency of nuclear lipid droplets in wild-type animals, we used a forward genetic screen to isolate mutants with abnormally large or abundant nuclear lipid droplets. Genetic analysis and cloning of three such mutants showed that the genes encode the lipid regulator SEIP-1/seipin, the inner nuclear membrane protein NEMP-1/Nemp1/TMEM194A, and a component of COPI vesicles called COPA-1/α-COP. We present several lines of evidence that the nuclear lipid droplet phenotype of copa-1 mutants results from a defect in retrieving mislocalized membrane proteins that normally reside in the endoplasmic reticulum. The seip-1 mutant causes most germ cells to have nuclear lipid droplets, the largest of which occupy more than a third of the nuclear volume. Nevertheless, the nuclear lipid droplets do not trigger apoptosis, and the germ cells differentiate into gametes that produce viable, healthy progeny. Thus, our results suggest that nuclear lipid droplets are detrimental to intestinal nuclei, but have no obvious deleterious effect on germ nuclei. Several human disorders such as obesity are associated with abnormal fat storage. Cells normally store fat in cytoplasmic organelles called lipid droplets. However, recent studies have shown that fat can also form inside of the cell nucleus, and the effects of nuclear fat are not known. Here we use the cell biology and genetics of the model organism C. elegans to study the causes and consequences of nuclear fat. We show that intestinal cells can contain nuclear fat, particularly during high-low-high changes in cytoplasmic fat that involve de novo fat synthesis. Nuclear fat is associated with multiple changes in intestinal nuclei that appear to represent damage and repair. Germ nuclei that normally differentiate into oocytes can also contain nuclear fat. In germ cells, however, even high levels of nuclear fat appear to cause little or no damage. Our results suggest that intestinal nuclei and germ cell nuclei might have different responses to nuclear fat in part because they differ in chromosomal organization at the nuclear envelope.
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Affiliation(s)
| | - Meghan C. Bacher
- Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - James R. Priess
- Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- Molecular and Cellular Biology Program, University of Washington, Seattle, Washington, United States of America
- Department of Biology, University of Washington, Seattle, Washington, United States of America
- * E-mail:
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10
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Liu Q, Chen C, Li M, Ke J, Huang Y, Bian Y, Guo S, Wu Y, Han Y, Liu M. Neurodevelopmental Toxicity of Polystyrene Nanoplastics in Caenorhabditis elegans and the Regulating Effect of Presenilin. ACS OMEGA 2020; 5:33170-33177. [PMID: 33403278 PMCID: PMC7774258 DOI: 10.1021/acsomega.0c04830] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 11/25/2020] [Indexed: 05/04/2023]
Abstract
As one of the most widely used materials, plastic polymer fragments can abrasively degrade into microplastic (MP) and smaller nanoplastic (NP) particles. The present study aimed to investigate the influence of particle size on neurodevelopmental toxicity induced by polystyrene nanoplastics (PS-NPs) in Caenorhabditis elegans and to explore the underlying potential mechanism. C. elegans were exposed to different concentrations of PS-NPs with various sizes (25, 50, and 100 nm) for 72 h. Our results showed that all of these PS-NPs could dose-dependently induce an increase in reactive oxygen species production and mitochondrial damage in C. elegans, resulting in inhibition of body length, head thrashes, body bending, and dopamine (DA) contents. A weaker neurotoxicity was found in 25 nm PS-NPs compared to 50 and 100 nm PS-NPs, which might be due to preferential cellular distribution and greater polymerization capability of the smaller particles. In addition, all these PS-NPs could induce lipofuscin accumulation and apoptosis independent of particle size, suggesting that oxidative damage and mitochondrial dysfunction may not be the only way responsible for NP-induced neurotoxic effects. Furthermore, the mutant test targeting two presenilin genes (sel-12 and hop-1) showed that sel-12 and hop-1 were involved in regulation of PS-NP-induced neurodevelopmental toxicity and mitochondrial damage. In conclusion, PS-NPs could induce neurodevelopmental toxicity dependent on particle sizes mediated by mitochondrial damage and DA reduction. Enhanced expression of presenilin plays a role in PS-NP-induced oxidative stress and neurodevelopmental toxicity.
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Affiliation(s)
- Qianyun Liu
- Department of Neurology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 200437, China
| | - Chunxiang Chen
- Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Mengting Li
- Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Jia Ke
- Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Yichen Huang
- Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Yuefeng Bian
- Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Shufen Guo
- Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Yang Wu
- Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Yan Han
- Department of Neurology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 200437, China
| | - Mingyuan Liu
- Department of Neurology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 200437, China
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11
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Dalfó D, Ding Y, Liang Q, Fong A, Cipriani PG, Piano F, Zheng JC, Qin Z, Hubbard EJA. A Genome-Wide RNAi Screen for Enhancers of a Germline Tumor Phenotype Caused by Elevated GLP-1/Notch Signaling in Caenorhabditis elegans. G3 (BETHESDA, MD.) 2020; 10:4323-4334. [PMID: 33077477 PMCID: PMC7718737 DOI: 10.1534/g3.120.401632] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 10/08/2020] [Indexed: 11/18/2022]
Abstract
Stem cells are tightly controlled in vivo Both the balance between self-renewal and differentiation and the rate of proliferation are often regulated by multiple factors. The Caenorhabditis elegans hermaphrodite germ line provides a simple and accessible system for studying stem cells in vivo In this system, GLP-1/Notch activity prevents the differentiation of distal germ cells in response to ligand production from the nearby distal tip cell, thereby supporting a stem cell pool. However, a delay in germline development relative to somatic gonad development can cause a pool of undifferentiated germ cells to persist in response to alternate Notch ligands expressed in the proximal somatic gonad. This pool of undifferentiated germ cells forms a proximal tumor that, in adulthood, blocks the oviduct. This type of "latent niche"-driven proximal tumor is highly penetrant in worms bearing the temperature-sensitive weak gain-of-function mutation glp-1(ar202) at the restrictive temperature. At the permissive temperature, few worms develop tumors. Nevertheless, several interventions elevate the penetrance of proximal tumor formation at the permissive temperature, including reduced insulin signaling or the ablation of distal-most sheath cells. To systematically identify genetic perturbations that enhance proximal tumor formation, we sought genes that, upon RNAi depletion, elevate the percentage of worms bearing proximal germline tumors in glp-1(ar202) at the permissive temperature. We identified 43 genes representing a variety of functional classes, the most enriched of which is "translation". Some of these genes also influence the distal germ line, and some are conserved genes for which genetic interactions with Notch were not previously known in this system.
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Affiliation(s)
- Diana Dalfó
- Skirball Institute of Biomolecular Medicine, Departments of Cell Biology and Pathology, NYU Grossman School of Medicine
| | | | | | - Alex Fong
- Skirball Institute of Biomolecular Medicine, Departments of Cell Biology and Pathology, NYU Grossman School of Medicine
| | - Patricia Giselle Cipriani
- Center for Genomics and Systems Biology, Department of Biology, New York University and Center for Genomics and Systems Biology, New York University Abu Dhabi
| | - Fabio Piano
- Center for Genomics and Systems Biology, Department of Biology, New York University and Center for Genomics and Systems Biology, New York University Abu Dhabi
| | | | - Zhao Qin
- School of Medicine, Tongji University
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Orthopedic Department of Tongji Hospital, School of Medicine, Tongji University
| | - E Jane Albert Hubbard
- Skirball Institute of Biomolecular Medicine, Departments of Cell Biology and Pathology, NYU Grossman School of Medicine
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12
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Hubbard EJA, Schedl T. Biology of the Caenorhabditis elegans Germline Stem Cell System. Genetics 2019; 213:1145-1188. [PMID: 31796552 PMCID: PMC6893382 DOI: 10.1534/genetics.119.300238] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Accepted: 09/09/2019] [Indexed: 12/14/2022] Open
Abstract
Stem cell systems regulate tissue development and maintenance. The germline stem cell system is essential for animal reproduction, controlling both the timing and number of progeny through its influence on gamete production. In this review, we first draw general comparisons to stem cell systems in other organisms, and then present our current understanding of the germline stem cell system in Caenorhabditis elegans In contrast to stereotypic somatic development and cell number stasis of adult somatic cells in C. elegans, the germline stem cell system has a variable division pattern, and the system differs between larval development, early adult peak reproduction and age-related decline. We discuss the cell and developmental biology of the stem cell system and the Notch regulated genetic network that controls the key decision between the stem cell fate and meiotic development, as it occurs under optimal laboratory conditions in adult and larval stages. We then discuss alterations of the stem cell system in response to environmental perturbations and aging. A recurring distinction is between processes that control stem cell fate and those that control cell cycle regulation. C. elegans is a powerful model for understanding germline stem cells and stem cell biology.
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Affiliation(s)
- E Jane Albert Hubbard
- Skirball Institute of Biomolecular Medicine, Departments of Cell Biology and Pathology, New York University School of Medicine, New York 10016
| | - Tim Schedl
- and Department of Genetics, Washington University School of Medicine, St. Louis, Missouri 63110
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13
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Kocsisova Z, Kornfeld K, Schedl T. Rapid population-wide declines in stem cell number and activity during reproductive aging in C. elegans. Development 2019; 146:dev173195. [PMID: 30936182 PMCID: PMC6503983 DOI: 10.1242/dev.173195] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 03/13/2019] [Indexed: 01/03/2023]
Abstract
C. elegans hermaphrodites display dramatic age-related decline of reproduction early in life, while somatic functions are still robust. To understand reproductive aging, we analyzed the assembly line of oocyte production that generates fertilized eggs. Aging germlines displayed both sporadic and population-wide changes. A small fraction of aging animals displayed endomitotic oocytes in the germline and other defects. By contrast, all animals displayed age-related decreases in germline size and function. As early as day 3 of adulthood, animals displayed fewer stem cells and a slower cell cycle, which combine to substantially decrease progenitor zone output. The C. elegans germline is the only adult tissue that contains stem cells, allowing the analysis of stem cells in aging. To investigate the mechanism of the decrease in stem cell number, we analyzed the Notch signaling pathway. The Notch effectors LST-1 and SYGL-1 displayed age-related decreases in expression domains, suggesting a role for Notch signaling in germline aging. The results indicate that although sporadic defects account for the sterility of some animals, population-wide changes account for the overall pattern of reproductive aging.
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Affiliation(s)
- Zuzana Kocsisova
- Department of Developmental Biology, Washington University School of Medicine, St Louis, MO 63110, USA
- Department of Genetics, Washington University School of Medicine, St Louis, MO 63110, USA
| | - Kerry Kornfeld
- Department of Developmental Biology, Washington University School of Medicine, St Louis, MO 63110, USA
| | - Tim Schedl
- Department of Genetics, Washington University School of Medicine, St Louis, MO 63110, USA
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Kocsisova Z, Mohammad A, Kornfeld K, Schedl T. Cell Cycle Analysis in the C. elegans Germline with the Thymidine Analog EdU. J Vis Exp 2018. [PMID: 30394383 DOI: 10.3791/58339] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Cell cycle analysis in eukaryotes frequently utilizes chromosome morphology, expression and/or localization of gene products required for various phases of the cell cycle, or the incorporation of nucleoside analogs. During S-phase, DNA polymerases incorporate thymidine analogs such as EdU or BrdU into chromosomal DNA, marking the cells for analysis. For C. elegans, the nucleoside analog EdU is fed to the worms during regular culture and is compatible with immunofluorescent techniques. The germline of C. elegans is a powerful model system for the studies of signaling pathways, stem cells, meiosis, and cell cycle because it is transparent, genetically facile, and meiotic prophase and cellular differentiation/gametogenesis occur in a linear assembly-like fashion. These features make EdU a great tool to study dynamic aspects of mitotically cycling cells and germline development. This protocol describes how to successfully prepare EdU bacteria, feed them to wild-type C. elegans hermaphrodites, dissect the hermaphrodite gonad, stain for EdU incorporation into DNA, stain with antibodies to detect various cell cycle and developmental markers, image the gonad and analyze the results. The protocol describes the variations in the method and analysis for the measurement of S-phase index, M-phase index, G2 duration, cell cycle duration, rate of meiotic entry, and rate of meiotic prophase progression. This method can be adapted to study the cell cycle or cell history in other tissues, stages, genetic backgrounds, and physiological conditions.
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Affiliation(s)
- Zuzana Kocsisova
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri; Department of Genetics, Washington University School of Medicine, St. Louis, Missouri
| | - Ariz Mohammad
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri
| | - Kerry Kornfeld
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri
| | - Tim Schedl
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri;
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Raiders SA, Eastwood MD, Bacher M, Priess JR. Binucleate germ cells in Caenorhabditis elegans are removed by physiological apoptosis. PLoS Genet 2018; 14:e1007417. [PMID: 30024879 PMCID: PMC6053125 DOI: 10.1371/journal.pgen.1007417] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 05/15/2018] [Indexed: 12/27/2022] Open
Abstract
Cell death plays a major role during C. elegans oogenesis, where over half of the oogenic germ cells die in a process termed physiological apoptosis. How germ cells are selected for physiological apoptosis, or instead become oocytes, is not understood. Most oocytes produce viable embryos when apoptosis is blocked, suggesting that physiological apoptosis does not function to cull defective germ cells. Instead, cells targeted for apoptosis may function as nurse cells; the germline is syncytial, and all germ cells appear to contribute cytoplasm to developing oocytes. C. elegans has been a leading model for the genetics and molecular biology of apoptosis and phagocytosis, but comparatively few studies have examined the cell biology of apoptotic cells. We used live imaging to identify and examine pre-apoptotic germ cells in the adult gonad. After initiating apoptosis, germ cells selectively export their mitochondria into the shared pool of syncytial cytoplasm; this transport appears to use the microtubule motor kinesin. The apoptotic cells then shrink as they expel most of their remaining cytoplasm, and close off from the syncytium. Shortly thereafter the apoptotic cells restructure their microtubule and actin cytoskeletons, possibly to maintain cell integrity; the microtubules form a novel, cortical array of stabilized microtubules, and actin and cofilin organize into giant cofilin-actin rods. We discovered that some apoptotic germ cells are binucleate; the binucleate germ cells can develop into binucleate oocytes in apoptosis-defective strains, and appear capable of producing triploid offspring. Our results suggest that the nuclear layer of the germline syncytium becomes folded during mitosis and growth, and that binucleate cells arise as the layer unfolds or everts; all of the binucleate cells are subsequently removed by apoptosis. These results show that physiological apoptosis targets at least two distinct populations of germ cells, and that the apoptosis machinery efficiently recognizes cells with two nuclei. Many germ cells die by apoptosis during the development of animal oocytes, including more than half of all germ cells in the model system C. elegans. How individual germ cells are selected for apoptosis, or survival, is not known. Here we study the cell biology of apoptosis. The C. elegans gonad is a syncytium, with nearly 1000 germ “cells” connected to a shared, core cytoplasm. Once apoptosis is initiated, germ cells selectively transport their mitochondria into the gonad core, apparently using the microtubule motor protein kinesin. The apoptotic cells next constrict, expelling most of their remaining cytoplasm into the core, and close off from the gonad core. The microtubule and actin cytoskeletons are remodeled and stabilized, presumably to maintain the integrity of the dying cell. The apoptotic cells form giant cofilin-actin rods, similar to rods described in stressed cultured cells and in human myopathies and neuropathies such as Alzheimer’s and Huntington’s disease. We show that some germ cells are binucleate; these cells appear to form during germline morphogenesis, and are removed by apoptosis. These results demonstrate heterogeneity between oogenic germ cells, and show that the apoptosis machinery efficiently recognizes and removes cells with two nuclei.
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Affiliation(s)
- Stephan A. Raiders
- Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Michael D. Eastwood
- Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Meghan Bacher
- Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - James R. Priess
- Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- Molecular and Cellular Biology Program, University of Washington, Seattle, Washington, United States of America
- Department of Biology, University of Washington, Seattle, Washington, United States of America
- * E-mail:
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Gutnik S, Thomas Y, Guo Y, Stoecklin J, Neagu A, Pintard L, Merlet J, Ciosk R. PRP-19, a conserved pre-mRNA processing factor and E3 ubiquitin ligase, inhibits the nuclear accumulation of GLP-1/Notch intracellular domain. Biol Open 2018; 7:bio034066. [PMID: 30012553 PMCID: PMC6078339 DOI: 10.1242/bio.034066] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 06/15/2018] [Indexed: 01/13/2023] Open
Abstract
The Notch signalling pathway is a conserved and widespread signalling paradigm, and its misregulation has been implicated in numerous disorders, including cancer. The output of Notch signalling depends on the nuclear accumulation of the Notch receptor intracellular domain (ICD). Using the Caenorhabditis elegans germline, where GLP-1/Notch-mediated signalling is essential for maintaining stem cells, we monitored GLP-1 in vivo We found that the nuclear enrichment of GLP-1 ICD is dynamic: while the ICD is enriched in germ cell nuclei during larval development, it is depleted from the nuclei in adult germlines. We found that this pattern depends on the ubiquitin proteolytic system and the splicing machinery and, identified the splicing factor PRP-19 as a candidate E3 ubiquitin ligase required for the nuclear depletion of GLP-1 ICD.
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Affiliation(s)
- Silvia Gutnik
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
- University of Basel, Petersplatz 1, 4001 Basel, Switzerland
| | - Yann Thomas
- Cell Cycle and Development, Institut Jacques Monod, UMR7592 CNRS - Université Paris Diderot, Sorbonne Paris Cité, F-75013 Paris, France
| | - Yanwu Guo
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0316 Oslo, Norway
| | - Janosch Stoecklin
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
- University of Basel, Petersplatz 1, 4001 Basel, Switzerland
| | - Anca Neagu
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Lionel Pintard
- Cell Cycle and Development, Institut Jacques Monod, UMR7592 CNRS - Université Paris Diderot, Sorbonne Paris Cité, F-75013 Paris, France
| | - Jorge Merlet
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine (IBPS), Developmental Biology Laboratory, UMR 7622, F-75005 Paris, France
| | - Rafal Ciosk
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0316 Oslo, Norway
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
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