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Hall AE, Klompstra D, Nance J. C. elegans Afadin is required for epidermal morphogenesis and functionally interfaces with the cadherin-catenin complex and RhoGAP PAC-1/ARHGAP21. Dev Biol 2024; 511:12-25. [PMID: 38556137 PMCID: PMC11088504 DOI: 10.1016/j.ydbio.2024.03.007] [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] [Received: 07/28/2023] [Revised: 03/07/2024] [Accepted: 03/25/2024] [Indexed: 04/02/2024]
Abstract
During epithelial morphogenesis, the apical junctions connecting cells must remodel as cells change shape and make new connections with their neighbors. In the C. elegans embryo, new apical junctions form when epidermal cells migrate and seal with one another to encase the embryo in skin ('ventral enclosure'), and junctions remodel when epidermal cells change shape to squeeze the embryo into a worm shape ('elongation'). The junctional cadherin-catenin complex (CCC), which links epithelial cells to each other and to cortical actomyosin, is essential for C. elegans epidermal morphogenesis. RNAi genetic enhancement screens have identified several genes encoding proteins that interact with the CCC to promote epidermal morphogenesis, including the scaffolding protein Afadin (AFD-1), whose depletion alone results in only minor morphogenesis defects. Here, by creating a null mutation in afd-1, we show that afd-1 provides a significant contribution to ventral enclosure and elongation on its own. Unexpectedly, we find that afd-1 mutant phenotypes are strongly modified by diet, revealing a previously unappreciated parental nutritional input to morphogenesis. We identify functional interactions between AFD-1 and the CCC by demonstrating that E-cadherin is required for the polarized distribution of AFD-1 to cell contact sites in early embryos. Finally, we show that afd-1 promotes the enrichment of polarity regulator, and CCC-interacting protein, PAC-1/ARHGAP21 to cell contact sites, and we identify genetic interactions suggesting that afd-1 and pac-1 regulate epidermal morphogenesis at least in part through parallel mechanisms. Our findings reveal that C. elegans AFD-1 makes a significant contribution to epidermal morphogenesis and functionally interfaces with core and associated CCC proteins.
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Affiliation(s)
- Allison E Hall
- Department of Cell Biology, NYU School of Medicine, New York, NY, 10016, USA; Skirball Institute of Biomolecular Medicine, NYU School of Medicine, New York, NY, 10016, USA; Regis University, Biology Department, Denver, CO, 80221, USA.
| | - Diana Klompstra
- Department of Cell Biology, NYU School of Medicine, New York, NY, 10016, USA; Skirball Institute of Biomolecular Medicine, NYU School of Medicine, New York, NY, 10016, USA
| | - Jeremy Nance
- Department of Cell Biology, NYU School of Medicine, New York, NY, 10016, USA; Skirball Institute of Biomolecular Medicine, NYU School of Medicine, New York, NY, 10016, USA; University of Wisconsin - Madison, Department of Cell and Regenerative Biology and Center for Quantitative Cell Imaging, Madison, WI, 53706, USA.
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Woodruff GC, Willis JH, Johnson E, Phillips PC. Widespread changes in gene expression accompany body size evolution in nematodes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.30.564729. [PMID: 37961435 PMCID: PMC10635002 DOI: 10.1101/2023.10.30.564729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Body size is a fundamental trait that drives multiple evolutionary and ecological patterns. Caenorhabditis inopinata is a fig-associated nematode that is exceptionally large relative to other members of the genus, including C. elegans. We previously showed that C. inopinata is large primarily due to postembryonic cell size expansion that occurs during the larval-to-adult transition. Here, we describe gene expression patterns in C. elegans and C. inopinata throughout this developmental period to understand the transcriptional basis of body size change. We performed RNA-seq in both species across the L3, L4, and adult stages. Most genes are differentially expressed across all developmental stages, consistent with C. inopinata's divergent ecology and morphology. We also used a model comparison approach to identify orthologs with divergent dynamics across this developmental period between the two species. This included genes connected to neurons, behavior, stress response, developmental timing, and small RNA/chromatin regulation. Multiple hypodermal collagens were also observed to harbor divergent developmental dynamics across this period, and genes important for molting and body morphology were also detected. Genes associated with TGF-β signaling revealed idiosyncratic and unexpected transcriptional patterns given their role in body size regulation in C. elegans. Widespread transcriptional divergence between these species is unexpected and may be a signature of the ecological and morphological divergence of C. inopinata. Alternatively, transcriptional turnover may be the rule in the Caenorhabditis genus, indicative of widespread developmental system drift among species. This work lays the foundation for future functional genetic studies interrogating the bases of body size evolution in this group.
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Affiliation(s)
- Gavin C Woodruff
- University of Oregon, Eugene, Oregon, USA
- Current institution: University of Oklahoma, Norman, Oklahoma, USA
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3
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Kyriazis M, Swas L, Orlova T. The Impact of Hormesis, Neuronal Stress Response, and Reproduction, upon Clinical Aging: A Narrative Review. J Clin Med 2023; 12:5433. [PMID: 37629475 PMCID: PMC10455615 DOI: 10.3390/jcm12165433] [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: 06/29/2023] [Revised: 08/05/2023] [Accepted: 08/17/2023] [Indexed: 08/27/2023] Open
Abstract
INTRODUCTION The primary objective of researchers in the biology of aging is to gain a comprehensive understanding of the aging process while developing practical solutions that can enhance the quality of life for older individuals. This involves a continuous effort to bridge the gap between fundamental biological research and its real-world applications. PURPOSE In this narrative review, we attempt to link research findings concerning the hormetic relationship between neurons and germ cells, and translate these findings into clinically relevant concepts. METHODS We conducted a literature search using PubMed, Embase, PLOS, Digital Commons Network, Google Scholar and Cochrane Library from 2000 to 2023, analyzing studies dealing with the relationship between hormetic, cognitive, and reproductive aspects of human aging. RESULTS The process of hormesis serves as a bridge between the biology of neuron-germ cell interactions on one hand, and the clinical relevance of these interactions on the other. Details concerning these processes are discussed here, emphasizing new research which strengthens the overall concept. CONCLUSIONS This review presents a scientifically and clinically relevant argument, claiming that maintaining a cognitively active lifestyle may decrease age-related degeneration, and improve overall health in aging. This is a totally novel approach which reflects current developments in several relevant aspects of our biology, technology, and society.
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Doering KRS, Ermakova G, Taubert S. Nuclear hormone receptor NHR-49 is an essential regulator of stress resilience and healthy aging in Caenorhabditis elegans. Front Physiol 2023; 14:1241591. [PMID: 37645565 PMCID: PMC10461480 DOI: 10.3389/fphys.2023.1241591] [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: 06/19/2023] [Accepted: 08/01/2023] [Indexed: 08/31/2023] Open
Abstract
The genome of Caenorhabditis elegans encodes 284 nuclear hormone receptor, which perform diverse functions in development and physiology. One of the best characterized of these is NHR-49, related in sequence and function to mammalian hepatocyte nuclear factor 4α and peroxisome proliferator-activated receptor α. Initially identified as regulator of lipid metabolism, including fatty acid catabolism and desaturation, additional important roles for NHR-49 have since emerged. It is an essential contributor to longevity in several genetic and environmental contexts, and also plays vital roles in the resistance to several stresses and innate immune response to infection with various bacterial pathogens. Here, we review how NHR-49 is integrated into pertinent signaling circuits and how it achieves its diverse functions. We also highlight areas for future investigation including identification of regulatory inputs that drive NHR-49 activity and identification of tissue-specific gene regulatory outputs. We anticipate that future work on this protein will provide information that could be useful for developing strategies to age-associated declines in health and age-related human diseases.
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Affiliation(s)
- Kelsie R. S. Doering
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, BC, Canada
- Edwin S. H. Leong Centre for Healthy Aging, The University of British Columbia, Vancouver, BC, Canada
- British Columbia Children’s Hospital Research Institute, Vancouver, BC, Canada
- Department of Medical Genetics, The University of British Columbia, Vancouver, BC, Canada
| | - Glafira Ermakova
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, BC, Canada
- Edwin S. H. Leong Centre for Healthy Aging, The University of British Columbia, Vancouver, BC, Canada
- British Columbia Children’s Hospital Research Institute, Vancouver, BC, Canada
- Department of Medical Genetics, The University of British Columbia, Vancouver, BC, Canada
| | - Stefan Taubert
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, BC, Canada
- Edwin S. H. Leong Centre for Healthy Aging, The University of British Columbia, Vancouver, BC, Canada
- British Columbia Children’s Hospital Research Institute, Vancouver, BC, Canada
- Department of Medical Genetics, The University of British Columbia, Vancouver, BC, Canada
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5
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Hall AE, Klompstra D, Nance J. C. elegans Afadin is required for epidermal morphogenesis and functionally interfaces with the cadherin-catenin complex and RhoGAP PAC-1/ARHGAP21. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.28.551013. [PMID: 37546884 PMCID: PMC10402129 DOI: 10.1101/2023.07.28.551013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
During epithelial morphogenesis, the apical junctions connecting cells must remodel as cells change shape and make new connections with their neighbors. In the C. elegans embryo, new apical junctions form when epidermal cells migrate and seal with one another to encase the embryo in skin ('ventral enclosure'), and junctions remodel when epidermal cells change shape to squeeze the embryo into a worm shape ('elongation'). The junctional cadherin-catenin complex (CCC), which links epithelial cells to each other and to cortical actomyosin, is essential for C. elegans epidermal morphogenesis. RNAi genetic enhancement screens have identified several proteins that interact with the CCC to promote epidermal morphogenesis, including the scaffolding protein Afadin (AFD-1), whose depletion alone results in only minor morphogenesis defects. Here, by creating a null mutation in afd-1 , we show that afd-1 provides a significant contribution to ventral enclosure and elongation on its own. Unexpectedly, we find that afd-1 mutant phenotypes are strongly modified by diet, revealing a previously unappreciated maternal nutritional input to morphogenesis. We identify functional interactions between AFD-1 and the CCC by demonstrating that E-cadherin is required for the polarized distribution of AFD-1 to cell contact sites in early embryos. Finally, we show that afd-1 promotes the enrichment of polarity regulator and CCC-interacting protein PAC-1/ARHGAP21 to cell contact sites, and identify genetic interactions suggesting that afd-1 and pac-1 regulate epidermal morphogenesis at least in part through parallel mechanisms. Our findings reveal that C. elegans AFD-1 makes a significant contribution to epidermal morphogenesis and functionally interfaces with core and associated CCC proteins.
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6
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Cao X, Xie Y, Yang H, Sun P, Xue B, Garcia LR, Zhang L. EAT-2 attenuates C. elegans development via metabolic remodeling in a chemically defined food environment. Cell Mol Life Sci 2023; 80:205. [PMID: 37450052 PMCID: PMC11072272 DOI: 10.1007/s00018-023-04849-x] [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: 04/12/2023] [Revised: 05/29/2023] [Accepted: 06/25/2023] [Indexed: 07/18/2023]
Abstract
Dietary intake and nutrient composition regulate animal growth and development; however, the underlying mechanisms remain elusive. Our previous study has shown that either the mammalian deafness homolog gene tmc-1 or its downstream acetylcholine receptor gene eat-2 attenuates Caenorhabditis elegans development in a chemically defined food CeMM (C. elegans maintenance medium) environment, but the underpinning mechanisms are not well-understood. Here, we found that, in CeMM food environment, for both eat-2 and tmc-1 fast-growing mutants, several fatty acid synthesis and elongation genes were highly expressed, while many fatty acid β-oxidation genes were repressed. Accordingly, dietary supplementation of individual fatty acids, such as monomethyl branch chain fatty acid C17ISO, palmitic acid and stearic acid significantly promoted wild-type animal development on CeMM, and mutations in either C17ISO synthesis gene elo-5 or elo-6 slowed the rapid growth of eat-2 mutant. Tissue-specific rescue experiments showed that elo-6 promoted animal development mainly in the intestine. Furthermore, transcriptome and metabolome analyses revealed that elo-6/C17ISO regulation of C. elegans development may be correlated with up-regulating expression of cuticle synthetic and hedgehog signaling genes, as well as promoting biosynthesis of amino acids, amino acid derivatives and vitamins. Correspondingly, we found that amino acid derivative S-adenosylmethionine and its upstream metabolite methionine sulfoxide significantly promoted C. elegans development on CeMM. This study demonstrated that C17ISO, palmitic acid, stearic acid, S-adenosylmethionine and methionine sulfoxide inhibited or bypassed the TMC-1 and EAT-2-mediated attenuation of development via metabolic remodeling, and allowed the animals to adapt to the new nutritional niche.
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Affiliation(s)
- Xuwen Cao
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 266071, Qingdao, China
- Laboratory of Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, 266237, Qingdao, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, 7 Nanhai Road, 266071, Qingdao, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
- Institute of Marine Science and Technology, Shandong University, 72 Binhai Road, 266237, Qingdao, China
| | - Yusu Xie
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 266071, Qingdao, China
- Laboratory of Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, 266237, Qingdao, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, 7 Nanhai Road, 266071, Qingdao, China
| | - Hanwen Yang
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 266071, Qingdao, China
- Laboratory of Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, 266237, Qingdao, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, 7 Nanhai Road, 266071, Qingdao, China
| | - Peiqi Sun
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 266071, Qingdao, China
- Laboratory of Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, 266237, Qingdao, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, 7 Nanhai Road, 266071, Qingdao, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Beining Xue
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 266071, Qingdao, China
- Laboratory of Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, 266237, Qingdao, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, 7 Nanhai Road, 266071, Qingdao, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - L Rene Garcia
- Department of Biology, Texas A&M University, College Station, TX, 77843-3258, USA
| | - Liusuo Zhang
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 266071, Qingdao, China.
- Laboratory of Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, 266237, Qingdao, China.
- Center for Ocean Mega-Science, Chinese Academy of Sciences, 7 Nanhai Road, 266071, Qingdao, China.
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Zhu J, Meng W, Man Lam S, Shui G, Huang X. Phosphatidylcholine deficiency increases ferroptosis susceptibility in the C. elegans germline. J Genet Genomics 2023; 50:318-329. [PMID: 36933794 DOI: 10.1016/j.jgg.2023.03.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 02/15/2023] [Accepted: 03/06/2023] [Indexed: 03/18/2023]
Abstract
Ferroptosis, a regulated and iron-dependent form of cell death characterized by peroxidation of membrane phospholipids, has tremendous potential for the therapy of human diseases. The causal link between phospholipid homeostasis and ferroptosis is incompletely understood. Here, we reveal that spin-4, a previously identified regulator of the "B12-one-carbon cycle-phosphatidylcholine (PC)" pathway, sustains germline development and fertility by ensuring PC sufficiency in the nematode Caenorhabditis elegans. Mechanistically, SPIN-4 regulates lysosomal activity which is required for B12-associated PC synthesis. PC deficiency-induced sterility can be rescued by reducing the levels of polyunsaturated fatty acids (PUFAs), reactive oxygen species (ROS) , and redox-active iron, which indicates that the sterility is mediated by germline ferroptosis. These results highlight the critical role of PC homeostasis in ferroptosis susceptibility and offer a new target for pharmacological approaches.
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Affiliation(s)
- Jinglin Zhu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wei Meng
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Sin Man Lam
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Guanghou Shui
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xun Huang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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8
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Wang K, Yang Z, Li X, Liu S, Wang L, Zhang H, Yu H. A Hepatocyte Nuclear Factor BtabHNF4 Mediates Desiccation Tolerance and Fecundity in Whitefly (Bemisia tabaci). ENVIRONMENTAL ENTOMOLOGY 2023; 52:138-147. [PMID: 36462170 DOI: 10.1093/ee/nvac103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Indexed: 06/17/2023]
Abstract
Hepatocyte nuclear factor 4 (HNF4) is essential for glucose homeostasis and lipid metabolism in insects. However, little is known about the role of HNF4 in whiteflies. In the present study, we identified a hepatocyte nuclear factor protein from Bemsia tabaci (Diptera: Drosophilidae) and named it BtabHNF4. The full-length of BtabHNF4 was 3,006 bp, encoding a sequence of 434 amino acids that contains a conserved zinc-finger DNA-binding domain (DBD) and a well-conserved ligand-binding domain (LBD). The temporal and spatial expression showed that BtabHNF4 was highly expressed in the female adult stage and abdominal tissues of B. tabaci. A leaf-mediated RNA interference method was used to explore the function of BtabHNF4 in whiteflies. Our results showed that the knockdown of BtabHNF4 influences the desiccation tolerance, egg production, and egg hatching rate of whiteflies. Additionally, BtabHNF4 silencing significantly inhibited the expression level of vitellogenin. These results expand the function of HNF4 and pave the way for understanding the molecular mechanisms of HNF4 in regulating multiple physiological processes.
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Affiliation(s)
- Kui Wang
- Department of Natural Resources, Henan Institute of Science and Technology, Xinxiang 453003, Henan Province, China
| | - Zhifang Yang
- Department of Natural Resources, Henan Institute of Science and Technology, Xinxiang 453003, Henan Province, China
| | - Xiang Li
- Department of Natural Resources, Henan Institute of Science and Technology, Xinxiang 453003, Henan Province, China
| | - Shunxiao Liu
- Department of Natural Resources, Henan Institute of Science and Technology, Xinxiang 453003, Henan Province, China
- College of Agrarian Technology and Natural Resources, Sumy National Agrarian University, Sumy 40021, Ukraine
| | - Liuhao Wang
- Department of Natural Resources, Henan Institute of Science and Technology, Xinxiang 453003, Henan Province, China
| | - Hongwei Zhang
- Department of Natural Resources, Henan Institute of Science and Technology, Xinxiang 453003, Henan Province, China
| | - Hao Yu
- Department of Natural Resources, Henan Institute of Science and Technology, Xinxiang 453003, Henan Province, China
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9
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The antidiabetic drug metformin aids bacteria in hijacking vitamin B12 from the environment through RcdA. Commun Biol 2023; 6:96. [PMID: 36693976 PMCID: PMC9873799 DOI: 10.1038/s42003-023-04475-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 01/12/2023] [Indexed: 01/25/2023] Open
Abstract
Years of use of the antidiabetic drug metformin has long been associated with the risk of vitamin B12 (B12) deficiency in type 2 diabetes (T2D) patients, although the underlying mechanisms are unclear. Accumulating evidence has shown that metformin may exert beneficial effects by altering the metabolism of the gut microbiota, but whether it induces human B12 deficiency via modulation of bacterial activity remains poorly understood. Here, we show that both metformin and the other biguanide drug phenformin markedly elevate the accumulation of B12 in E. coli. By functional and genomic analysis, we demonstrate that both biguanides can significantly increase the expression of B12 transporter genes, and depletions of vital ones, such as tonB, nearly completely abolish the drugs' effect on bacterial B12 accumulation. Via high-throughput screens in E. coli and C. elegans, we reveal that the TetR-type transcription factor RcdA is required for biguanide-mediated promotion of B12 accumulation and the expressions of B12 transporter genes in bacteria. Together, our study unveils that the antidiabetic drug metformin helps bacteria gather B12 from the environment by increasing the expressions of B12 transporter genes in an RcdA-dependent manner, which may theoretically reduce the B12 supply to T2D patients taking the drug over time.
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10
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The metabolite alpha-ketobutyrate extends lifespan by promoting peroxisomal function in C. elegans. Nat Commun 2023; 14:240. [PMID: 36646719 PMCID: PMC9842765 DOI: 10.1038/s41467-023-35899-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 01/06/2023] [Indexed: 01/18/2023] Open
Abstract
Metabolism is intimately linked to aging. There is a growing number of studies showing that endogenous metabolites may delay aging and improve healthspan. Through the analysis of existing transcriptome data, we discover a link between activation of the transsulfuration pathway and a transcriptional program involved in peroxisome function and biogenesis in long-lived glp-1(e2141ts) mutant Caenorhabditis elegans worms. Subsequently, we show that supplementation with α-ketobutyrate, an intermediate of the transsulfuration pathway, extends lifespan in wild-type worms. Alpha-ketobutyrate augments the production of NAD+ via the lactate dehydrogenase LDH-1, leading to SIR-2.1/SIRT1-mediated enhanced peroxisome function and biogenesis, along with a concomitant increase in the expression of acox-1.2/ACOX1 in the peroxisomal fatty acid β-oxidation pathway. ACOX-1.2/ACOX1 promotes H2O2 formation, thereby resulting in activation of SKN-1/NRF2. This transcription factor in turn extends the lifespan of worms by driving expression of autophagic and lysosomal genes. Finally, we show that α-ketobutyrate also delays the cellular senescence in fibroblast cells through the SIRT1-ACOX1-H2O2-NRF2 pathway. This finding uncovers a previously unknown role for α-ketobutyrate in organismal lifespan and healthspan by coordinating the NAD+-SIRT1 signaling and peroxisomal function.
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Feng M, Gao B, Garcia LR, Sun Q. Microbiota-derived metabolites in regulating the development and physiology of Caenorhabditis elegans. Front Microbiol 2023; 14:1035582. [PMID: 36925470 PMCID: PMC10011103 DOI: 10.3389/fmicb.2023.1035582] [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: 09/07/2022] [Accepted: 02/09/2023] [Indexed: 03/08/2023] Open
Abstract
Microbiota consist of microorganisms that provide essential health benefits and contribute to the animal's physiological homeostasis. Microbiota-derived metabolites are crucial mediators in regulating host development, system homeostasis, and overall fitness. In this review, by focusing on the animal model Caenorhabditis elegans, we summarize key microbial metabolites and their molecular mechanisms that affect animal development. We also provide, from a bacterial perspective, an overview of host-microbiota interaction networks used for maintaining host physiological homeostasis. Moreover, we discuss applicable methodologies for profiling new bacterial metabolites that modulate host developmental signaling pathways. Microbiota-derived metabolites have the potential to be diagnostic biomarkers for diseases, as well as promising targets for engineering therapeutic interventions against animal developmental or health-related defects.
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Affiliation(s)
- Min Feng
- Department of Chemical Engineering, Texas A&M University, College Station, TX, United States
| | - Baizhen Gao
- Department of Chemical Engineering, Texas A&M University, College Station, TX, United States
| | - L Rene Garcia
- Department of Biology, Texas A&M University, College Station, TX, United States
| | - Qing Sun
- Department of Chemical Engineering, Texas A&M University, College Station, TX, United States
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12
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Crittenden SL, Seidel HS, Kimble J. Analysis of the C. elegans Germline Stem Cell Pool. Methods Mol Biol 2023; 2677:1-36. [PMID: 37464233 DOI: 10.1007/978-1-0716-3259-8_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
The Caenorhabditis elegans germline is an excellent model for studying the genetic and molecular regulation of stem cell self-renewal and progression of cells from a stem cell state to a differentiated state. The germline tissue is organized in an assembly line with the germline stem cell (GSC) pool at one end and differentiated gametes at the other. A simple mesenchymal niche caps the GSC pool and maintains GSCs in an undifferentiated state by signaling through the conserved Notch pathway. Notch signaling activates transcription of the key GSC regulators lst-1 and sygl-1 proteins in a gradient through the GSC pool. LST-1 and SYGL-1 proteins work with PUF RNA regulators in a self-renewal hub to maintain the GSC pool. In this chapter, we present methods for characterizing the C. elegans GSC pool and early stages of germ cell differentiation. The methods include examination of germlines in living and fixed worms, cell cycle analysis, and analysis of markers. We also discuss assays to separate mutant phenotypes that affect the stem cell vs. differentiation decision from those that affect germ cell processes more generally.
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Affiliation(s)
- Sarah L Crittenden
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA.
| | - Hannah S Seidel
- Department of Biology, Eastern Michigan University, Ypsilanti, MI, USA
| | - Judith Kimble
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
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13
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Heppert JK, Lickwar CR, Tillman MC, Davis BR, Davison JM, Lu HY, Chen W, Busch-Nentwich EM, Corcoran DL, Rawls JF. Conserved roles for Hnf4 family transcription factors in zebrafish development and intestinal function. Genetics 2022; 222:iyac133. [PMID: 36218393 PMCID: PMC9713462 DOI: 10.1093/genetics/iyac133] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 07/20/2022] [Indexed: 12/13/2022] Open
Abstract
Transcription factors play important roles in the development of the intestinal epithelium and its ability to respond to endocrine, nutritional, and microbial signals. Hepatocyte nuclear factor 4 family nuclear receptors are liganded transcription factors that are critical for the development and function of multiple digestive organs in vertebrates, including the intestinal epithelium. Zebrafish have 3 hepatocyte nuclear factor 4 homologs, of which, hnf4a was previously shown to mediate intestinal responses to microbiota in zebrafish larvae. To discern the functions of other hepatocyte nuclear factor 4 family members in zebrafish development and intestinal function, we created and characterized mutations in hnf4g and hnf4b. We addressed the possibility of genetic redundancy amongst these factors by creating double and triple mutants which showed different rates of survival, including apparent early lethality in hnf4a; hnf4b double mutants and triple mutants. RNA sequencing performed on digestive tracts from single and double mutant larvae revealed extensive changes in intestinal gene expression in hnf4a mutants that were amplified in hnf4a; hnf4g mutants, but limited in hnf4g mutants. Changes in hnf4a and hnf4a; hnf4g mutants were reminiscent of those seen in mice including decreased expression of genes involved in intestinal function and increased expression of cell proliferation genes, and were validated using transgenic reporters and EdU labeling in the intestinal epithelium. Gnotobiotics combined with RNA sequencing also showed hnf4g has subtler roles than hnf4a in host responses to microbiota. Overall, phenotypic changes in hnf4a single mutants were strongly enhanced in hnf4a; hnf4g double mutants, suggesting a conserved partial genetic redundancy between hnf4a and hnf4g in the vertebrate intestine.
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Affiliation(s)
- Jennifer K Heppert
- Department of Molecular Genetics and Microbiology, Duke Microbiome Center, Duke University School of Medicine, Durham, NC 27710, USA
- Department of Medicine, Division of Gastroenterology and Hepatology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Colin R Lickwar
- Department of Molecular Genetics and Microbiology, Duke Microbiome Center, Duke University School of Medicine, Durham, NC 27710, USA
| | - Matthew C Tillman
- Department of Molecular Genetics and Microbiology, Duke Microbiome Center, Duke University School of Medicine, Durham, NC 27710, USA
| | - Briana R Davis
- Department of Molecular Genetics and Microbiology, Duke Microbiome Center, Duke University School of Medicine, Durham, NC 27710, USA
| | - James M Davison
- Department of Molecular Genetics and Microbiology, Duke Microbiome Center, Duke University School of Medicine, Durham, NC 27710, USA
| | - Hsiu-Yi Lu
- Department of Molecular Genetics and Microbiology, Duke Microbiome Center, Duke University School of Medicine, Durham, NC 27710, USA
| | - Wei Chen
- Center for Genomics and Computational Biology, Duke University School of Medicine, Durham, NC 27710, USA
| | | | - David L Corcoran
- Center for Genomics and Computational Biology, Duke University School of Medicine, Durham, NC 27710, USA
| | - John F Rawls
- Department of Molecular Genetics and Microbiology, Duke Microbiome Center, Duke University School of Medicine, Durham, NC 27710, USA
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14
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Qin S, Wang Y, Li L, Liu J, Xiao C, Duan D, Hao W, Qin C, Chen J, Yao L, Zhang R, You J, Zheng JS, Shen E, Wu L. Early-life vitamin B12 orchestrates lipid peroxidation to ensure reproductive success via SBP-1/SREBP1 in Caenorhabditis elegans. Cell Rep 2022; 40:111381. [PMID: 36130518 DOI: 10.1016/j.celrep.2022.111381] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 07/05/2022] [Accepted: 08/27/2022] [Indexed: 11/03/2022] Open
Abstract
Vitamin B12 (B12) deficiency is a critical problem worldwide. Such deficiency in infants has long been known to increase the propensity to develop obesity and diabetes later in life through unclear mechanisms. Here, we establish a Caenorhabditis elegans model to study how early-life B12 impacts adult health. We find that early-life B12 deficiency causes increased lipogenesis and lipid peroxidation in adult worms, which in turn induces germline defects through ferroptosis. Mechanistically, we show the central role of the methionine cycle-SBP-1/SREBP1-lipogenesis axis in programming adult traits by early-life B12. Moreover, SBP-1/SREBP1 participates in a crucial feedback loop with NHR-114/HNF4 to maintain cellular B12 homeostasis. Inhibition of SBP-1/SREBP1-lipogenesis signaling and ferroptosis later in life can reverse disorders in adulthood when B12 cannot. Overall, this study provides mechanistic insights into the life-course effects of early-life B12 on the programming of adult health and identifies potential targets for future interventions for adiposity and infertility.
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Affiliation(s)
- Shenlu Qin
- Fudan University, Shanghai, China; Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China; Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China; Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Yihan Wang
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China; Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China; Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Lili Li
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China; Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China; Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Junli Liu
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China; Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China; Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Congmei Xiao
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China; Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China; Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Duo Duan
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China; Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China; Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Wanyu Hao
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China; Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China; Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Chunxia Qin
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China; Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China; Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Jie Chen
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China; Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China; Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Luxia Yao
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China; Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China; Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Runshuai Zhang
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China; Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China; Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Jia You
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China; Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China; Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Ju-Sheng Zheng
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China; Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China; Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Enzhi Shen
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China; Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China; Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Lianfeng Wu
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China; Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China; Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China.
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15
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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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16
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Palikaras K, SenGupta T, Nilsen H, Tavernarakis N. Assessment of dopaminergic neuron degeneration in a C. elegans model of Parkinson’s disease. STAR Protoc 2022; 3:101264. [PMID: 35403008 PMCID: PMC8983426 DOI: 10.1016/j.xpro.2022.101264] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Transgenic Caenorhabditis elegans that expresses the full-length wild-type human α-synuclein in dopaminergic neurons provides a well-established Parkinson’s disease (PD) nematode model. Here, we present a detailed protocol to monitor and dissect the molecular underpinnings of age-associated neurodegeneration using this PD nematode model. This protocol includes preparation of nematode growth media and bacterial food sources, as well as procedures for nematode growth, synchronization, and treatment. We then describe procedures to assess dopaminergic neuronal death in vivo using fluorescence imaging. For complete details on the use and execution of this protocol, please refer to SenGupta et al. (2021). A Parkinson’s disease nematode model to study α-synuclein-mediated neurotoxicity Comprehensive approach for scoring cell death of dopaminergic neurons in C. elegans Genetic tools to investigate the tissue specific effects on neurodegeneration
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17
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Reproductive Span of Caenorhabditis elegans Is Extended by Microbacterium sp. J Nematol 2022; 54:20220010. [PMID: 35860519 PMCID: PMC9260829 DOI: 10.2478/jofnem-2022-0010] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Indexed: 11/20/2022] Open
Abstract
Abstract
The reproductive span (RS) of organisms could be affected by different factors during their lifetime. In the model nematode, Caenorhabditis elegans, RS is affected by both genetic and environmental factors. However, none of the factors identified so far were related to environmental bacteria, which may incidentally appear anywhere in the habitats of C. elegans. We aimed to find environmental bacteria that could affect the RS of C. elegans and related species. We tested 109 bacterial isolates and found that Microbacterium sp. CFBb37 increased the RS and lifespan of C. elegans but reduced its brood size. We studied the effect of M. sp. CFBb37 on the RS of Caenorhabditis briggsae, Caenorhabditis tropicalis, and another Rhabditidae family species, Protorhabditis sp., and found similar trends of RS extension in all three cases, suggesting that this bacterial species may induce the extension of RS broadly among Caenorhabditis species and possibly for many other Rhabditidae. This work will facilitate future research on the mechanism underlying the bacterial extension of RS of nematodes and possibly other animals.
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18
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McDonagh A, Crew J, van der Linden AM. Dietary vitamin B12 regulates chemosensory receptor gene expression via the MEF2 transcription factor in Caenorhabditis elegans. G3 (BETHESDA, MD.) 2022; 12:6580222. [PMID: 35512190 PMCID: PMC9157118 DOI: 10.1093/g3journal/jkac107] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 04/24/2022] [Indexed: 02/02/2023]
Abstract
Dynamic changes in chemoreceptor gene expression levels in sensory neurons are one strategy that an animal can use to modify their responses to dietary changes. However, the mechanisms underlying diet-dependent modulation of chemosensory gene expression are unclear. Here, we show that the expression of the srh-234 chemoreceptor gene localized in a single ADL sensory neuron type of Caenorhabditis elegans is downregulated when animals are fed a Comamonas aquatica bacterial diet, but not on an Escherichia coli diet. Remarkably, this diet-modulated effect on srh-234 expression is dependent on the micronutrient vitamin B12 endogenously produced by Comamonas aq. bacteria. Excess propionate and genetic perturbations in the canonical and shunt propionate breakdown pathways are able to override the repressive effects of vitamin B12 on srh-234 expression. The vitamin B12-mediated regulation of srh-234 expression levels in ADL requires the MEF-2 MADS domain transcription factor, providing a potential mechanism by which dietary vitamin B12 may transcriptionally tune individual chemoreceptor genes in a single sensory neuron type, which in turn may change animal responses to biologically relevant chemicals in their diet.
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Affiliation(s)
- Aja McDonagh
- Department of Biology, University of Nevada, Reno, NV 89557, USA
| | - Jeannette Crew
- Department of Biology, University of Nevada, Reno, NV 89557, USA
| | - Alexander M van der Linden
- Department of Biology, University of Nevada, Reno, NV 89557, USA,Corresponding author: Department of Biology, University of Nevada, Reno, NV 89557, USA.
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19
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Karengera A, Sterken MG, Kammenga JE, Riksen JAG, Dinkla IJT, Murk AJ. Differential expression of genes in C. elegans reveals transcriptional responses to indirect-acting xenobiotic compounds and insensitivity to 2,3,7,8-tetrachlorodibenzodioxin. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 233:113344. [PMID: 35219257 DOI: 10.1016/j.ecoenv.2022.113344] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 02/12/2022] [Accepted: 02/20/2022] [Indexed: 05/14/2023]
Abstract
Caenorhabditis elegans is a well-established model organism for toxicity testing of chemical substances. We recently demonstrated its potential for bioanalysis of the toxic potency of chemical contaminants in water. While many detoxification genes are homologues to those in mammalians, C. elegans is reported to be deficient in cytochrome CYP1-like P450 metabolism and that its aryl hydrocarbon receptor (AhR) homolog encoded by ahr-1 purportedly does not interact with dioxins or any other known xenobiotic ligand. This suggests that C. elegans is insensitive for compounds that require bioactivation (indirectly acting compounds) and for dioxins or dioxin-like compounds. This study analysed genome-wide gene expression of the nematode in response to 30 μM of aflatoxin B1 (AFB1), benzo(a)pyrene (B(a)P), Aroclor 1254 (PCB1254), and 10 μM of 2,3,7,8-tetrachlorodibenzodioxin (TCDD). After 24 h of exposure in the early L4 larval stage, microarray analysis revealed 182, 86, and 321 differentially expressed genes in the nematodes treated with 30 μM of AFB1, B(a)P, and PCB1254, respectively. Among these genes, many encode xenobiotic-metabolizing enzymes, and their transcription levels were among the highest-ranked fold-changed genes. Interestingly, only one gene (F59B1.8) was upregulated in the nematodes exposed to 10 μM TCDD. Genes related to metabolic processes and catalytic activity were the most induced by exposure to 30 μM of AFB1, B(a)P, and PCB1254. Despite the genotoxic nature of AFB1 and B(a)P, no differential expression was found in the genes encoding DNA repair and cell cycle checkpoint proteins. Analysis of concentration-response curves was performed to determine the Lowest Observed Transcriptomic Effect Levels (LOTEL) of AFB1, B(a)P, and PCB1254. The obtained LOTEL values showed that gene expression changes in C. elegans are more sensitive to toxicants than reproductive effects. Overall, transcriptional responses of metabolic enzymes suggest that the nematode does metabolize AFB1, B(a)P, and PCB1254. Our findings also support the assumption that the transcription factor AhR homolog in C. elegans does not bind typical xenobiotic ligands, rendering the nematode transcriptionally insensitive to TCDD effects.
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Affiliation(s)
- Antoine Karengera
- Wageningen University, Department of Animal Sciences, Marine Animal Ecology Group, De Elst 1, 6708 WD Wageningen, The Netherlands; Wetsus, European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, 8911 MA Leeuwarden, The Netherlands
| | - Mark G Sterken
- Wageningen University, Plant Sciences, Laboratory of Nematology, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Jan E Kammenga
- Wageningen University, Plant Sciences, Laboratory of Nematology, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Joost A G Riksen
- Wageningen University, Plant Sciences, Laboratory of Nematology, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Inez J T Dinkla
- Wetsus, European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, 8911 MA Leeuwarden, The Netherlands
| | - Albertinka J Murk
- Wageningen University, Department of Animal Sciences, Marine Animal Ecology Group, De Elst 1, 6708 WD Wageningen, The Netherlands.
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20
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Ortiz A, Vega NM, Ratzke C, Gore J. Interspecies bacterial competition regulates community assembly in the C. elegans intestine. THE ISME JOURNAL 2021; 15:2131-2145. [PMID: 33589765 PMCID: PMC8245486 DOI: 10.1038/s41396-021-00910-4] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 01/19/2021] [Accepted: 01/22/2021] [Indexed: 01/31/2023]
Abstract
From insects to mammals, a large variety of animals hold in their intestines complex bacterial communities that play an important role in health and disease. To further our understanding of how intestinal bacterial communities assemble and function, we study the C. elegans microbiota with a bottom-up approach by feeding this nematode with bacterial monocultures as well as mixtures of two to eight bacterial species. We find that bacteria colonizing well in monoculture do not always do well in co-cultures due to interspecies bacterial interactions. Moreover, as community diversity increases, the ability to colonize the worm gut in monoculture becomes less important than interspecies interactions for determining community assembly. To explore the role of host-microbe adaptation, we compare bacteria isolated from C. elegans intestines and non-native isolates, and we find that the success of colonization is determined more by a species' taxonomy than by the isolation source. Lastly, by comparing the assembled microbiotas in two C. elegans mutants, we find that innate immunity via the p38 MAPK pathway decreases bacterial abundances yet has little influence on microbiota composition. These results highlight that bacterial interspecies interactions, more so than host-microbe adaptation or gut environmental filtering, play a dominant role in the assembly of the C. elegans microbiota.
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Affiliation(s)
- Anthony Ortiz
- grid.116068.80000 0001 2341 2786Physics of Living Systems, Department of Physics, Massachusetts Institute of Technology, Cambridge, MA USA ,grid.116068.80000 0001 2341 2786Microbiology Graduate Program, Massachusetts Institute of Technology, Cambridge, MA USA
| | - Nicole M. Vega
- grid.116068.80000 0001 2341 2786Physics of Living Systems, Department of Physics, Massachusetts Institute of Technology, Cambridge, MA USA ,grid.189967.80000 0001 0941 6502Present Address: Department of Biology, Emory University, Atlanta, GA USA
| | - Christoph Ratzke
- grid.116068.80000 0001 2341 2786Physics of Living Systems, Department of Physics, Massachusetts Institute of Technology, Cambridge, MA USA ,grid.10392.390000 0001 2190 1447Present Address: Interfaculty Institute for Microbiology and Infection Medicine Tübingen (IMIT), Cluster of Excellence ‘CMFI’, University of Tübingen, Tübingen, Germany
| | - Jeff Gore
- grid.116068.80000 0001 2341 2786Physics of Living Systems, Department of Physics, Massachusetts Institute of Technology, Cambridge, MA USA ,grid.116068.80000 0001 2341 2786Microbiology Graduate Program, Massachusetts Institute of Technology, Cambridge, MA USA
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21
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Manterola M, Palominos MF, Calixto A. The Heritability of Behaviors Associated With the Host Gut Microbiota. Front Immunol 2021; 12:658551. [PMID: 34054822 PMCID: PMC8155505 DOI: 10.3389/fimmu.2021.658551] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 04/12/2021] [Indexed: 12/13/2022] Open
Abstract
What defines whether the interaction between environment and organism creates a genetic memory able to be transferred to subsequent generations? Bacteria and the products of their metabolism are the most ubiquitous biotic environments to which every living organism is exposed. Both microbiota and host establish a framework where environmental and genetic factors are integrated to produce adaptive life traits, some of which can be inherited. Thus, the interplay between host and microbe is a powerful model to study how phenotypic plasticity is inherited. Communication between host and microbe can occur through diverse molecules such as small RNAs (sRNAs) and the RNA interference machinery, which have emerged as mediators and carriers of heritable environmentally induced responses. Notwithstanding, it is still unclear how the organism integrates sRNA signaling between different tissues to orchestrate a systemic bacterially induced response that can be inherited. Here we discuss current evidence of heritability produced by the intestinal microbiota from several species. Neurons and gut are the sensing systems involved in transmitting changes through transcriptional and post-transcriptional modifications to the gonads. Germ cells express inflammatory receptors, and their development and function are regulated by host and bacterial metabolites and sRNAs thus suggesting that the dynamic interplay between host and microbe underlies the host's capacity to transmit heritable behaviors. We discuss how the host detects changes in the microbiota that can modulate germ cells genomic functions. We also explore the nature of the interactions that leave permanent or long-term memory in the host and propose mechanisms by which the microbiota can regulate the development and epigenetic reprogramming of germ cells, thus influencing the inheritance of the host. We highlight the vast contribution of the bacterivore nematode C. elegans and its commensal and pathogenic bacteria to the understanding on how behavioral adaptations can be inter and transgenerational inherited.
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Affiliation(s)
- Marcia Manterola
- Programa de Genética Humana, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - M. Fernanda Palominos
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaiso, Chile
- Programa de Doctorado en Ciencias, mención Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaiso, Chile
| | - Andrea Calixto
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaiso, Chile
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22
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Hartman JH, Widmayer SJ, Bergemann CM, King DE, Morton KS, Romersi RF, Jameson LE, Leung MCK, Andersen EC, Taubert S, Meyer JN. Xenobiotic metabolism and transport in Caenorhabditis elegans. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2021; 24:51-94. [PMID: 33616007 PMCID: PMC7958427 DOI: 10.1080/10937404.2021.1884921] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Caenorhabditis elegans has emerged as a major model in biomedical and environmental toxicology. Numerous papers on toxicology and pharmacology in C. elegans have been published, and this species has now been adopted by investigators in academic toxicology, pharmacology, and drug discovery labs. C. elegans has also attracted the interest of governmental regulatory agencies charged with evaluating the safety of chemicals. However, a major, fundamental aspect of toxicological science remains underdeveloped in C. elegans: xenobiotic metabolism and transport processes that are critical to understanding toxicokinetics and toxicodynamics, and extrapolation to other species. The aim of this review was to initially briefly describe the history and trajectory of the use of C. elegans in toxicological and pharmacological studies. Subsequently, physical barriers to chemical uptake and the role of the worm microbiome in xenobiotic transformation were described. Then a review of what is and is not known regarding the classic Phase I, Phase II, and Phase III processes was performed. In addition, the following were discussed (1) regulation of xenobiotic metabolism; (2) review of published toxicokinetics for specific chemicals; and (3) genetic diversity of these processes in C. elegans. Finally, worm xenobiotic transport and metabolism was placed in an evolutionary context; key areas for future research highlighted; and implications for extrapolating C. elegans toxicity results to other species discussed.
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Affiliation(s)
- Jessica H Hartman
- Nicholas School of the Environment, Duke University, Durham, North Carolina
| | - Samuel J Widmayer
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois, United States
| | | | - Dillon E King
- Nicholas School of the Environment, Duke University, Durham, North Carolina
| | - Katherine S Morton
- Nicholas School of the Environment, Duke University, Durham, North Carolina
| | - Riccardo F Romersi
- Nicholas School of the Environment, Duke University, Durham, North Carolina
| | - Laura E Jameson
- School of Mathematical and Natural Sciences, Arizona State University - West Campus, Glendale, Arizona, United States
| | - Maxwell C K Leung
- School of Mathematical and Natural Sciences, Arizona State University - West Campus, Glendale, Arizona, United States
| | - Erik C Andersen
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois, United States
| | - Stefan Taubert
- Dept. Of Medical Genetics, Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute, the University of British Colombia, Vancouver, BC, Canada
| | - Joel N Meyer
- Nicholas School of the Environment, Duke University, Durham, North Carolina
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23
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Brinkmann V, Schiavi A, Shaik A, Puchta DR, Ventura N. Dietary and environmental factors have opposite AhR-dependent effects on C. elegans healthspan. Aging (Albany NY) 2020; 13:104-133. [PMID: 33349622 PMCID: PMC7835051 DOI: 10.18632/aging.202316] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Accepted: 11/08/2020] [Indexed: 12/14/2022]
Abstract
Genetic, dietary, and environmental factors concurrently shape the aging process. The aryl hydrocarbon receptor (AhR) was discovered as a dioxin-binding transcription factor involved in the metabolism of different environmental toxicants in vertebrates. Since then, the variety of pathophysiological processes regulated by the AhR has grown, ranging from immune response, metabolic pathways, and aging. Many modulators of AhR activity may impact on aging and age-associated pathologies, but, whether their effects are AhR-dependent has never been explored. Here, using Caenorhabditis elegans, as an elective model organism for aging studies, we show for the first time that lack of CeAHR-1 can have opposite effects on health and lifespan in a context-dependent manner. Using known mammalian AhR modulators we found that, ahr-1 protects against environmental insults (benzo(a)pyrene and UVB light) and identified a new role for AhR-bacterial diet interaction in animal lifespan, stress resistance, and age-associated pathologies. We narrowed down the dietary factor to a bacterially extruded metabolite likely involved in tryptophan metabolism. This is the first study clearly establishing C. elegans as a good model organism to investigate evolutionarily conserved functions of AhR-modulators and -regulated processes, indicating it can be exploited to contribute to the discovery of novel information about AhR in mammals.
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Affiliation(s)
- Vanessa Brinkmann
- Leibniz Institute for Environmental Medicine, Auf’m Hennekamp 50, 40225 Düsseldorf, Germany
| | - Alfonso Schiavi
- Leibniz Institute for Environmental Medicine, Auf’m Hennekamp 50, 40225 Düsseldorf, Germany.,Institute of Clinical Chemistry and Laboratory Diagnostic, Heinrich Heine University Düsseldorf, Moorenstr 5, 40225 Düsseldorf, Germany
| | - Anjumara Shaik
- Leibniz Institute for Environmental Medicine, Auf’m Hennekamp 50, 40225 Düsseldorf, Germany.,Institute of Clinical Chemistry and Laboratory Diagnostic, Heinrich Heine University Düsseldorf, Moorenstr 5, 40225 Düsseldorf, Germany
| | - Daniel Rüdiger Puchta
- Leibniz Institute for Environmental Medicine, Auf’m Hennekamp 50, 40225 Düsseldorf, Germany
| | - Natascia Ventura
- Leibniz Institute for Environmental Medicine, Auf’m Hennekamp 50, 40225 Düsseldorf, Germany.,Institute of Clinical Chemistry and Laboratory Diagnostic, Heinrich Heine University Düsseldorf, Moorenstr 5, 40225 Düsseldorf, Germany
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24
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Stuhr NL, Curran SP. Bacterial diets differentially alter lifespan and healthspan trajectories in C. elegans. Commun Biol 2020; 3:653. [PMID: 33159120 PMCID: PMC7648844 DOI: 10.1038/s42003-020-01379-1] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 10/14/2020] [Indexed: 01/21/2023] Open
Abstract
Diet is one of the more variable aspects in life due to the variety of options that organisms are exposed to in their natural habitats. In the laboratory, C. elegans are raised on bacterial monocultures, traditionally the E. coli B strain OP50, and spontaneously occurring microbial contaminants are removed to limit experimental variability because diet-including the presence of contaminants-can exert a potent influence over animal physiology. In order to diversify the menu available to culture C. elegans in the lab, we have isolated and cultured three such microbes: Methylobacterium, Xanthomonas, and Sphingomonas. The nutritional composition of these bacterial foods is unique, and when fed to C. elegans, can differentially alter multiple life history traits including development, reproduction, and metabolism. In light of the influence each food source has on specific physiological attributes, we comprehensively assessed the impact of these bacteria on animal health and devised a blueprint for utilizing different food combinations over the lifespan, in order to promote longevity. The expansion of the bacterial food options to use in the laboratory will provide a critical tool to better understand the complexities of bacterial diets and subsequent changes in physiology and gene expression.
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Affiliation(s)
- Nicole L Stuhr
- Leonard Davis School of Gerontology, University of Southern California, 3715 McClintock Ave, Los Angeles, CA, 90089, USA
- Dornsife College of Letters, Arts, and Science, Department of Molecular and Computational Biology, University of Southern California, 1050 Childs Way, Los Angeles, CA, 90089, USA
| | - Sean P Curran
- Leonard Davis School of Gerontology, University of Southern California, 3715 McClintock Ave, Los Angeles, CA, 90089, USA.
- Dornsife College of Letters, Arts, and Science, Department of Molecular and Computational Biology, University of Southern California, 1050 Childs Way, Los Angeles, CA, 90089, USA.
- Norris Comprehensive Cancer Center, University of Southern California, 1441 Eastlake Ave, Los Angeles, CA, 90033, USA.
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25
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Giese GE, Walker MD, Ponomarova O, Zhang H, Li X, Minevich G, Walhout AJ. Caenorhabditis elegans methionine/S-adenosylmethionine cycle activity is sensed and adjusted by a nuclear hormone receptor. eLife 2020; 9:60259. [PMID: 33016879 PMCID: PMC7561351 DOI: 10.7554/elife.60259] [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: 06/22/2020] [Accepted: 10/02/2020] [Indexed: 01/17/2023] Open
Abstract
Vitamin B12 is an essential micronutrient that functions in two metabolic pathways: the canonical propionate breakdown pathway and the methionine/S-adenosylmethionine (Met/SAM) cycle. In Caenorhabditis elegans, low vitamin B12, or genetic perturbation of the canonical propionate breakdown pathway results in propionate accumulation and the transcriptional activation of a propionate shunt pathway. This propionate-dependent mechanism requires nhr-10 and is referred to as ‘B12-mechanism-I’. Here, we report that vitamin B12 represses the expression of Met/SAM cycle genes by a propionate-independent mechanism we refer to as ‘B12-mechanism-II’. This mechanism is activated by perturbations in the Met/SAM cycle, genetically or due to low dietary vitamin B12. B12-mechanism-II requires nhr-114 to activate Met/SAM cycle gene expression, the vitamin B12 transporter, pmp-5, and adjust influx and efflux of the cycle by activating msra-1 and repressing cbs-1, respectively. Taken together, Met/SAM cycle activity is sensed and transcriptionally adjusted to be in a tight metabolic regime.
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Affiliation(s)
- Gabrielle E Giese
- Program in Systems Biology and Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, United States
| | - Melissa D Walker
- Program in Systems Biology and Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, United States
| | - Olga Ponomarova
- Program in Systems Biology and Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, United States
| | - Hefei Zhang
- Program in Systems Biology and Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, United States
| | - Xuhang Li
- Program in Systems Biology and Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, United States
| | - Gregory Minevich
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, United States
| | - Albertha Jm Walhout
- Program in Systems Biology and Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, United States
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26
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Palominos MF, Calixto A. Quantification of Bacteria Residing in Caenorhabditis elegans Intestine. Bio Protoc 2020; 10:e3605. [PMID: 33659570 PMCID: PMC7842830 DOI: 10.21769/bioprotoc.3605] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 02/23/2020] [Accepted: 03/29/2020] [Indexed: 11/02/2022] Open
Abstract
Quantification of intestinal colonization by pathogenic or commensal bacteria constitute a critical part of the analysis to understand host-microbe interactions during different time points of their interplay. Here we detail a method to isolate non-pathogenic and pathogenic bacteria from C. elegans intestines, and classify gut phenotypes induced by bacterial pathogens using fluorescently-tagged bacteria. Furthermore, these methods can be used to isolate and identify new culturable bacterial species from natural microbiomes of wild nematodes.
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Affiliation(s)
- M. Fernanda Palominos
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Playa Ancha, Valparaiso, Chile
| | - Andrea Calixto
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Playa Ancha, Valparaiso, Chile
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27
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Urrutia A, García-Angulo VA, Fuentes A, Caneo M, Legüe M, Urquiza S, Delgado SE, Ugalde J, Burdisso P, Calixto A. Bacterially produced metabolites protect C. elegans neurons from degeneration. PLoS Biol 2020; 18:e3000638. [PMID: 32208418 PMCID: PMC7092960 DOI: 10.1371/journal.pbio.3000638] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 02/18/2020] [Indexed: 12/20/2022] Open
Abstract
Caenorhabditis elegans and its cognate bacterial diet comprise a reliable, widespread model to study diet and microbiota effects on host physiology. Nonetheless, how diet influences the rate at which neurons die remains largely unknown. A number of models have been used in C. elegans as surrogates for neurodegeneration. One of these is a C. elegans strain expressing a neurotoxic allele of the mechanosensory abnormality protein 4 (MEC-4d) degenerin/epithelial Na+ (DEG/ENaC) channel, which causes the progressive degeneration of the touch receptor neurons (TRNs). Using this model, our study evaluated the effect of various dietary bacteria on neurodegeneration dynamics. Although degeneration of TRNs was steady and completed at adulthood in the strain routinely used for C. elegans maintenance (Escherichia coli OP50), it was significantly reduced in environmental and other laboratory bacterial strains. Strikingly, neuroprotection reached more than 40% in the E. coli HT115 strain. HT115 protection was long lasting well into old age of animals and was not restricted to the TRNs. Small amounts of HT115 on OP50 bacteria as well as UV-killed HT115 were still sufficient to produce neuroprotection. Early growth of worms in HT115 protected neurons from degeneration during later growth in OP50. HT115 diet promoted the nuclear translocation of DAF-16 (ortholog of the FOXO family of transcription factors), a phenomenon previously reported to underlie neuroprotection caused by down-regulation of the insulin receptor in this system. Moreover, a daf-16 loss-of-function mutation abolishes HT115-driven neuroprotection. Comparative genomics, transcriptomics, and metabolomics approaches pinpointed the neurotransmitter γ-aminobutyric acid (GABA) and lactate as metabolites differentially produced between E. coli HT115 and OP50. HT115 mutant lacking glutamate decarboxylase enzyme genes (gad), which catalyze the conversion of GABA from glutamate, lost the ability to produce GABA and also to stop neurodegeneration. Moreover, in situ GABA supplementation or heterologous expression of glutamate decarboxylase in E. coli OP50 conferred neuroprotective activity to this strain. Specific C. elegans GABA transporters and receptors were required for full HT115-mediated neuroprotection. Additionally, lactate supplementation also increased anterior ventral microtubule (AVM) neuron survival in OP50. Together, these results demonstrate that bacterially produced GABA and other metabolites exert an effect of neuroprotection in the host, highlighting the role of neuroactive compounds of the diet in nervous system homeostasis.
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Affiliation(s)
- Arles Urrutia
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
- Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago de Chile, Chile
| | - Víctor A. García-Angulo
- Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago de Chile, Chile
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago de Chile, Chile
| | - Andrés Fuentes
- Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago de Chile, Chile
| | - Mauricio Caneo
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
- Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago de Chile, Chile
| | - Marcela Legüe
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
- Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago de Chile, Chile
| | - Sebastián Urquiza
- Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago de Chile, Chile
| | - Scarlett E. Delgado
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
- Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago de Chile, Chile
| | - Juan Ugalde
- Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago de Chile, Chile
| | - Paula Burdisso
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario and Plataforma Argentina de Biología Estructural y Metabolómica (PLABEM), Rosario, Santa Fe, Argentina
| | - Andrea Calixto
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
- Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago de Chile, Chile
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28
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Viau C, Haçariz O, Karimian F, Xia J. Comprehensive phenotyping and transcriptome profiling to study nanotoxicity in C. elegans. PeerJ 2020; 8:e8684. [PMID: 32149031 PMCID: PMC7049462 DOI: 10.7717/peerj.8684] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 02/04/2020] [Indexed: 12/11/2022] Open
Abstract
Engineered nanoparticles are used at an increasing rate in both industry and medicine without fully understanding their impact on health and environment. The nematode Caenorhabditis elegans is a suitable model to study the toxic effects of nanoparticles as it is amenable to comprehensive phenotyping, such as locomotion, growth, neurotoxicity and reproduction. In this study, we systematically evaluated the effects of silver (Ag) and five metal oxide nanoparticles: SiO2, CeO2, CuO, Al2O3 and TiO2. The results showed that Ag and SiO2 exposures had the most toxic effects on locomotion velocity, growth and reproduction, whereas CeO2, Al2O3 and CuO exposures were mostly neurotoxic. We further performed RNAseq to compare the gene expression profiles underlying Ag and SiO2toxicities. Gene set enrichment analyses revealed that exposures to Ag and SiO2consistently downregulated several biological processes (regulations in locomotion, reproductive process and cell growth) and pathways (neuroactive ligand-receptor interaction, wnt and MAPK signaling, etc.), with opposite effects on genes involved in innate immunity. Our results contribute to mechanistic insights into toxicity of Ag and SiO2 nanoparticles and demonstrated that C. elegans as a valuable model for nanotoxicity assessment.
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Affiliation(s)
- Charles Viau
- Institute of Parasitology, McGill University, Montreal, Canada
| | - Orçun Haçariz
- Institute of Parasitology, McGill University, Montreal, Canada
| | - Farial Karimian
- Institute of Parasitology, McGill University, Montreal, Canada
| | - Jianguo Xia
- Institute of Parasitology, McGill University, Montreal, Canada.,Department of Animal Science, McGill University, Montreal, Quebec, Canada
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29
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Rashid S, Pho KB, Mesbahi H, MacNeil LT. Nutrient Sensing and Response Drive Developmental Progression in Caenorhabditis elegans. Bioessays 2020; 42:e1900194. [PMID: 32003906 DOI: 10.1002/bies.201900194] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 12/22/2019] [Indexed: 12/18/2022]
Abstract
In response to nutrient limitation, many animals, including Caenorhabditis elegans, slow or arrest their development. This process requires mechanisms that sense essential nutrients and induce appropriate responses. When faced with nutrient limitation, C. elegans can induce both short and long-term survival strategies, including larval arrest, decreased developmental rate, and dauer formation. To select the most advantageous strategy, information from many different sensors must be integrated into signaling pathways, including target of rapamycin (TOR) and insulin, that regulate developmental progression. Here, how nutrient information is sensed and integrated into developmental decisions that determine developmental rate and progression in C. elegans is reviewed.
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Affiliation(s)
- Sabih Rashid
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, L8S 4K1, Ontario, Canada
| | - Kim B Pho
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, L8S 4K1, Ontario, Canada
| | - Hiva Mesbahi
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, L8S 4K1, Ontario, Canada
| | - Lesley T MacNeil
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, L8S 4K1, Ontario, Canada.,Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, L8S 4K1, Ontario, Canada.,Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, L8S 4K1, Ontario, Canada
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30
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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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31
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Zhou JJ, Chun L, Liu JF. A Comprehensive Understanding of Dietary Effects on C. elegans Physiology. Curr Med Sci 2019; 39:679-684. [PMID: 31612382 DOI: 10.1007/s11596-019-2091-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 03/14/2019] [Indexed: 02/07/2023]
Abstract
Diet has been shown to play an important role in human physiology. It is a predominant exogenous factor regulating the composition of gut microbiota, and dietary intervention holds promise for treatment of diseases such as obesity, type 2 diabetes, and malnutrition. Furthermore, it was reported that diet has significant effects on physiological processes of C. elegans, including reproduction, fat storage, and aging. To reveal novel signaling pathways responsive to different diets, C. elegans and its bacterial diet were used as an interspecies model system to mimic the interaction between host and gut microbiota. Most signaling pathways identified in C. elegans are highly conserved across different species, including humans. A better understanding of these pathways can, therefore, help to develop interventions for human diseases. In this article, we summarize recent achievements on molecular mechanisms underlying the response of C. elegans to different diets and discuss their relevance to human health.
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Affiliation(s)
- Jie-Jun Zhou
- Collaborative Innovation Center for Brain Science, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Lei Chun
- Collaborative Innovation Center for Brain Science, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China.
| | - Jian-Feng Liu
- Collaborative Innovation Center for Brain Science, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China.
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32
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Yang W, Petersen C, Pees B, Zimmermann J, Waschina S, Dirksen P, Rosenstiel P, Tholey A, Leippe M, Dierking K, Kaleta C, Schulenburg H. The Inducible Response of the Nematode Caenorhabditis elegans to Members of Its Natural Microbiota Across Development and Adult Life. Front Microbiol 2019; 10:1793. [PMID: 31440221 PMCID: PMC6693516 DOI: 10.3389/fmicb.2019.01793] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 07/22/2019] [Indexed: 12/11/2022] Open
Abstract
The biology of all organisms is influenced by the associated community of microorganisms. In spite of its importance, it is usually not well understood how exactly this microbiota affects host functions and what are the underlying molecular processes. To rectify this knowledge gap, we took advantage of the nematode Caenorhabditis elegans as a tractable, experimental model system and assessed the inducible transcriptome response after colonization with members of its native microbiota. For this study, we focused on two isolates of the genus Ochrobactrum. These bacteria are known to be abundant in the nematode’s microbiota and are capable of colonizing and persisting in the nematode gut, even under stressful conditions. The transcriptome response was assessed across development and three time points of adult life, using general and C. elegans-specific enrichment analyses to identify affected functions. Our assessment revealed an influence of the microbiota members on the nematode’s dietary response, development, fertility, immunity, and energy metabolism. This response is mainly regulated by a GATA transcription factor, most likely ELT-2, as indicated by the enrichment of (i) the GATA motif in the promoter regions of inducible genes and (ii) of ELT-2 targets among the differentially expressed genes. We compared our transcriptome results with a corresponding previously characterized proteome data set, highlighting a significant overlap in the differentially expressed genes, the affected functions, and ELT-2 target genes. Our analysis further identified a core set of 86 genes that consistently responded to the microbiota members across development and adult life, including several C-type lectin-like genes and genes known to be involved in energy metabolism or fertility. We additionally assessed the consequences of induced gene expression with the help of metabolic network model analysis, using a previously established metabolic network for C. elegans. This analysis complemented the enrichment analyses by revealing an influence of the Ochrobactrum isolates on C. elegans energy metabolism and furthermore metabolism of specific amino acids, fatty acids, and also folate biosynthesis. Our findings highlight the multifaceted impact of naturally colonizing microbiota isolates on C. elegans life history and thereby provide a framework for further analysis of microbiota-mediated host functions.
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Affiliation(s)
- Wentao Yang
- Research Group Evolutionary Ecology and Genetics, Zoological Institute, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Carola Petersen
- Research Group Evolutionary Ecology and Genetics, Zoological Institute, Christian-Albrechts-Universität zu Kiel, Kiel, Germany.,Research Group Comparative Immunobiology, Zoological Institute, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Barbara Pees
- Research Group Comparative Immunobiology, Zoological Institute, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Johannes Zimmermann
- Research Group Medical Systems Biology, Institute for Experimental Medicine, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Silvio Waschina
- Research Group Medical Systems Biology, Institute for Experimental Medicine, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Philipp Dirksen
- Research Group Evolutionary Ecology and Genetics, Zoological Institute, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Philip Rosenstiel
- Institute for Clinical Molecular Biology, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Andreas Tholey
- Research Group Proteomics, Institute for Experimental Medicine, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Matthias Leippe
- Research Group Comparative Immunobiology, Zoological Institute, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Katja Dierking
- Research Group Evolutionary Ecology and Genetics, Zoological Institute, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Christoph Kaleta
- Research Group Medical Systems Biology, Institute for Experimental Medicine, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Hinrich Schulenburg
- Research Group Evolutionary Ecology and Genetics, Zoological Institute, Christian-Albrechts-Universität zu Kiel, Kiel, Germany.,Max Planck Institute for Evolutionary Biology, Plön, Germany
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Kyriazis M. Ageing Throughout History: The Evolution of Human Lifespan. J Mol Evol 2019; 88:57-65. [PMID: 31197416 DOI: 10.1007/s00239-019-09896-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 06/06/2019] [Indexed: 12/20/2022]
Abstract
It is not surprising that one of the most complex phenomena in nature is that of ageing. It does not only bear biological interest, but it is also associated with cultural, psychological, social and even philosophical issues. It is therefore to be expected that a great deal of research is being performed in order to study the evolution of ageing and, more specifically, the evolution of human ageing. Historical aspects of this evolution will be discussed. Evidence from a variety of sources shows that the human lifespan is increasing, and may well continue to increase to levels that are difficult to predict. In addition, the most important theories about ageing based on evolutionary principles will be examined. Examples are mutation accumulation, antagonistic pleiotropy and the disposable soma theory. Finally, a section about future evolution of human ageing, based upon newly emerging research, will shed some light and provide speculative-provocative ideas about the future of ageing in humans.
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Biology is the root of variability: cautionary tales in Caenorhabditis elegans biology. Biochem Soc Trans 2019; 47:887-896. [PMID: 31127069 DOI: 10.1042/bst20190001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 04/29/2019] [Accepted: 04/30/2019] [Indexed: 12/31/2022]
Abstract
Abstract
Reproducibility is critical for the standardization, interpretation, and progression of research. However, many factors increase variability and reduce reproducibility. In Caenorhabditis elegans research, there are many possible causes of variability that may explain why experimental outcomes sometimes differ between laboratories and between experiments. Factors contributing to experimental variability include the genetic background of both C. elegans and its bacterial diet, differences in media composition, intergenerational and transgenerational effects that may be carried over for generations, and the use of chemicals or reagents that may have unexpected consequences. This review summarizes sources of variability in C. elegans research and serves to identify laboratory practices that could influence reproducibility.
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Zečić A, Dhondt I, Braeckman BP. The nutritional requirements of Caenorhabditis elegans. GENES AND NUTRITION 2019; 14:15. [PMID: 31080524 PMCID: PMC6501307 DOI: 10.1186/s12263-019-0637-7] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 04/10/2019] [Indexed: 12/14/2022]
Abstract
Animals require sufficient intake of a variety of nutrients to support their development, somatic maintenance and reproduction. An adequate diet provides cell building blocks, chemical energy to drive cellular processes and essential nutrients that cannot be synthesised by the animal, or at least not in the required amounts. Dietary requirements of nematodes, including Caenorhabditis elegans have been extensively studied with the major aim to develop a chemically defined axenic medium that would support their growth and reproduction. At the same time, these studies helped elucidating important aspects of nutrition-related biochemistry and metabolism as well as the establishment of C. elegans as a powerful model in studying evolutionarily conserved pathways, and the influence of the diet on health.
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Affiliation(s)
- Aleksandra Zečić
- Department of Biology, Laboratory of Aging Physiology and Molecular Evolution, Ghent University, 9000 Ghent, Belgium
| | - Ineke Dhondt
- Department of Biology, Laboratory of Aging Physiology and Molecular Evolution, Ghent University, 9000 Ghent, Belgium
| | - Bart P Braeckman
- Department of Biology, Laboratory of Aging Physiology and Molecular Evolution, Ghent University, 9000 Ghent, Belgium
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O’Donnell MP, Chao PH, Kammenga JE, Sengupta P. Rictor/TORC2 mediates gut-to-brain signaling in the regulation of phenotypic plasticity in C. elegans. PLoS Genet 2018; 14:e1007213. [PMID: 29415022 PMCID: PMC5819832 DOI: 10.1371/journal.pgen.1007213] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 02/20/2018] [Accepted: 01/22/2018] [Indexed: 01/03/2023] Open
Abstract
Animals integrate external cues with information about internal conditions such as metabolic state to execute the appropriate behavioral and developmental decisions. Information about food quality and quantity is assessed by the intestine and transmitted to modulate neuronal functions via mechanisms that are not fully understood. The conserved Target of Rapamycin complex 2 (TORC2) controls multiple processes in response to cellular stressors and growth factors. Here we show that TORC2 coordinates larval development and adult behaviors in response to environmental cues and feeding state in the bacterivorous nematode C. elegans. During development, pheromone, bacterial food, and temperature regulate expression of the daf-7 TGF-β and daf-28 insulin-like peptide in sensory neurons to promote a binary decision between reproductive growth and entry into the alternate dauer larval stage. We find that TORC2 acts in the intestine to regulate neuronal expression of both daf-7 and daf-28, which together reflect bacterial-diet dependent feeding status, thus providing a mechanism for integration of food signals with external cues in the regulation of neuroendocrine gene expression. In the adult, TORC2 similarly acts in the intestine to modulate food-regulated foraging behaviors via a PDF-2/PDFR-1 neuropeptide signaling-dependent pathway. We also demonstrate that genetic variation affects food-dependent larval and adult phenotypes, and identify quantitative trait loci (QTL) associated with these traits. Together, these results suggest that TORC2 acts as a hub for communication of feeding state information from the gut to the brain, thereby contributing to modulation of neuronal function by internal state. Decision-making in all animals, including humans, involves weighing available information about the external environment as well as the animals’ internal conditions. Information about the environment is obtained via the sensory nervous system, whereas internal state can be assessed via cues such as levels of hormones or nutrients. How multiple external and internal inputs are processed in the nervous system to drive behavior or development is not fully understood. In this study, we examine how the nematode C. elegans integrates dietary information received by the gut with environmental signals to alter nervous system function. We have found that a signaling complex, called TORC2, acts in the gut to relay nutrition signals to alter hormonal signaling by the nervous system in C. elegans. Altered neuronal signaling in turn affects a food-dependent binary developmental decision in larvae, as well as food-dependent foraging behaviors in adults. Our results provide a mechanism by which animals prioritize specific signals such as feeding status to appropriately alter their development and/or behavior.
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Affiliation(s)
- Michael P. O’Donnell
- Department of Biology and National Center for Behavioral Genomics, Brandeis University, Waltham, MA, United States of America
- * E-mail: (MPO); (PS)
| | - Pin-Hao Chao
- Department of Biology and National Center for Behavioral Genomics, Brandeis University, Waltham, MA, United States of America
| | - Jan E. Kammenga
- Laboratory of Nematology, Wageningen University and Research, Wageningen, The Netherlands
| | - Piali Sengupta
- Department of Biology and National Center for Behavioral Genomics, Brandeis University, Waltham, MA, United States of America
- * E-mail: (MPO); (PS)
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GERBABA TEKLUK, GREEN-HARRISON LUKE, BURET ANDREG. Modeling Host-Microbiome Interactions in Caenorhabditis elegans. J Nematol 2018. [DOI: 10.21307/jofnem-2017-082] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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38
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Chaudhari SN, Mukherjee M, Vagasi AS, Bi G, Rahman MM, Nguyen CQ, Paul L, Selhub J, Kipreos ET. Bacterial Folates Provide an Exogenous Signal for C. elegans Germline Stem Cell Proliferation. Dev Cell 2017; 38:33-46. [PMID: 27404357 DOI: 10.1016/j.devcel.2016.06.013] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 05/04/2016] [Accepted: 06/09/2016] [Indexed: 11/29/2022]
Abstract
Here we describe an in vitro primary culture system for Caenorhabditis elegans germline stem cells. This culture system was used to identify a bacterial folate as a positive regulator of germ cell proliferation. Folates are a family of B-complex vitamins that function in one-carbon metabolism to allow the de novo synthesis of amino acids and nucleosides. We show that germ cell proliferation is stimulated by the folate 10-formyl-tetrahydrofolate-Glun both in vitro and in animals. Other folates that can act as vitamins to rescue folate deficiency lack this germ cell stimulatory activity. The bacterial folate precursor dihydropteroate also promotes germ cell proliferation in vitro and in vivo, despite its inability to promote one-carbon metabolism. The folate receptor homolog FOLR-1 is required for the stimulation of germ cells by 10-formyl-tetrahydrofolate-Glun and dihydropteroate. This work defines a folate and folate-related compound as exogenous signals to modulate germ cell proliferation.
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Affiliation(s)
- Snehal N Chaudhari
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
| | | | - Alexandra S Vagasi
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
| | - Gaofeng Bi
- Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA
| | - Mohammad M Rahman
- Department of Genetics, University of Georgia, Athens, GA 30602, USA
| | - Christine Q Nguyen
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
| | - Ligi Paul
- Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA
| | - Jacob Selhub
- Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA
| | - Edward T Kipreos
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA.
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Schulenburg H, Félix MA. The Natural Biotic Environment of Caenorhabditis elegans. Genetics 2017; 206:55-86. [PMID: 28476862 PMCID: PMC5419493 DOI: 10.1534/genetics.116.195511] [Citation(s) in RCA: 247] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 02/28/2017] [Indexed: 01/05/2023] Open
Abstract
Organisms evolve in response to their natural environment. Consideration of natural ecological parameters are thus of key importance for our understanding of an organism's biology. Curiously, the natural ecology of the model species Caenorhabditis elegans has long been neglected, even though this nematode has become one of the most intensively studied models in biological research. This lack of interest changed ∼10 yr ago. Since then, an increasing number of studies have focused on the nematode's natural ecology. Yet many unknowns still remain. Here, we provide an overview of the currently available information on the natural environment of C. elegans We focus on the biotic environment, which is usually less predictable and thus can create high selective constraints that are likely to have had a strong impact on C. elegans evolution. This nematode is particularly abundant in microbe-rich environments, especially rotting plant matter such as decomposing fruits and stems. In this environment, it is part of a complex interaction network, which is particularly shaped by a species-rich microbial community. These microbes can be food, part of a beneficial gut microbiome, parasites and pathogens, and possibly competitors. C. elegans is additionally confronted with predators; it interacts with vector organisms that facilitate dispersal to new habitats, and also with competitors for similar food environments, including competitors from congeneric and also the same species. Full appreciation of this nematode's biology warrants further exploration of its natural environment and subsequent integration of this information into the well-established laboratory-based research approaches.
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Affiliation(s)
- Hinrich Schulenburg
- Zoological Institute, Christian-Albrechts Universitaet zu Kiel, 24098 Kiel, Germany
| | - Marie-Anne Félix
- Institut de Biologie de l'Ecole Normale Supérieure, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, École Normale Supérieure, L'université de Recherche Paris Sciences et Lettres, 75005, France
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40
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Xu J, Jiang Y, Wan L, Wang Q, Huang Z, Liu Y, Wu Y, Chen Z, Liu X. Feeding recombinant E. coli with GST-mBmKTX fusion protein increases the fecundity and lifespan of Caenorhabditis elegans. Peptides 2017; 89:1-8. [PMID: 28088444 DOI: 10.1016/j.peptides.2017.01.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 01/05/2017] [Accepted: 01/06/2017] [Indexed: 12/29/2022]
Abstract
Scorpion venom could be a useful treatment for a variety of diseases, such as cancer, epilepsy and analgesia. BmKTX is a polypeptide extracts from scorpion venom (PESV), which have attracted much attention from researchers in recent years. mBmKTX is a mutant polypeptide according to the amino acid sequence of BmKTX. We expressed it with the vector pGEX-4T-1 in Escherichia coli, and Caenorhabditis elegans were used as the animal model and fed with the strains. In this study, the expression of pGEX-mBmKTX was analyzed by SDS-PAGE, and GST-mBmKTX purified from pGEX-mBmKTX as a glutathione S-transferase (GST)-tagged fusion protein is approximately 30kDa. The secondary structure prediction shows that mBmKTX is mainly composed of approximately 13% β-sheet and 86% loop. A food clearance assay and brood size assay indicated that the worms fed pGEX-mBmKTX ate more and had greater fecundity than those fed the empty vector. A lifespan analysis demonstrated that mBmKTX could significantly prolong the lifespan of C. elegans, with an increase of 22.5% compared with the control. Behavioral assays confirmed that mBmKTX had no influence on the locomotion of C. elegans. In addition, microarray analysis and quantitative real-time PCR demonstrated that there are 320 differentially expressed genes, 182 of which are related to reproduction, growth and lifespan. In conclusion, the data suggested that mBmKTX has potential utility for increasing fecundity and animal survival.
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Affiliation(s)
- Jie Xu
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, and School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, China
| | - Yajie Jiang
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, and School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, China
| | - Lu Wan
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, and School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, China
| | - Qi Wang
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, and School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, China
| | - Zebo Huang
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, and School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, China; Guangdong Province Key Laboratory for Biotechnology Drug Candidates, School of Biosciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - Yongmei Liu
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, and School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, China
| | - Yingliang Wu
- School of Life Science, Wuhan University, Wuhan 430071, China
| | - Zongyun Chen
- School of Life Science, Wuhan University, Wuhan 430071, China
| | - Xin Liu
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, and School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, China.
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41
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Laws KM, Drummond-Barbosa D. Control of Germline Stem Cell Lineages by Diet and Physiology. Results Probl Cell Differ 2017; 59:67-99. [PMID: 28247046 DOI: 10.1007/978-3-319-44820-6_3] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Tight coupling of reproduction to environmental factors and physiological status is key to long-term species survival. In particular, highly conserved pathways modulate germline stem cell lineages according to nutrient availability. This chapter focuses on recent in vivo studies in genetic model organisms that shed light on how diet-dependent signals control the proliferation, maintenance, and survival of adult germline stem cells and their progeny. These signaling pathways can operate intrinsically in the germ line, modulate the niche, or act through intermediate organs to influence stem cells and their differentiating progeny. In addition to illustrating the extent of dietary regulation of reproduction, findings from these studies have implications for fertility during aging or disease states.
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Affiliation(s)
- Kaitlin M Laws
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 21205, USA
| | - Daniela Drummond-Barbosa
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 21205, USA. .,Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 21205, USA.
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42
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Bodofsky S, Koitz F, Wightman B. CONSERVED AND EXAPTED FUNCTIONS OF NUCLEAR RECEPTORS IN ANIMAL DEVELOPMENT. NUCLEAR RECEPTOR RESEARCH 2017; 4:101305. [PMID: 29333434 PMCID: PMC5761748 DOI: 10.11131/2017/101305] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The nuclear receptor gene family includes 18 members that are broadly conserved among multiple disparate animal phyla, indicating that they trace their evolutionary origins to the time at which animal life arose. Typical nuclear receptors contain two major domains: a DNA-binding domain and a C-terminal domain that may bind a lipophilic hormone. Many of these nuclear receptors play varied roles in animal development, including coordination of life cycle events and cellular differentiation. The well-studied genetic model systems of Drosophila, C. elegans, and mouse permit an evaluation of the extent to which nuclear receptor function in development is conserved or exapted (repurposed) over animal evolution. While there are some specific examples of conserved functions and pathways, there are many clear examples of exaptation. Overall, the evolutionary theme of exaptation appears to be favored over strict functional conservation. Despite strong conservation of DNA-binding domain sequences and activity, the nuclear receptors prove to be highly-flexible regulators of animal development.
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Affiliation(s)
- Shari Bodofsky
- Biology Department, Muhlenberg College, 2400 Chew St., Allentown, PA 18104
| | - Francine Koitz
- Biology Department, Muhlenberg College, 2400 Chew St., Allentown, PA 18104
| | - Bruce Wightman
- Biology Department, Muhlenberg College, 2400 Chew St., Allentown, PA 18104
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Abstract
The Caenorhabditis elegans germline is an excellent model for studying the regulation of a pool of stem cells and progression of cells from a stem cell state to a differentiated state. At the tissue level, the germline is organized in an assembly line with the germline stem cell (GSC) pool at one end and differentiated cells at the other. A simple mesenchymal niche caps the GSC region of the germline and maintains GSCs in an undifferentiated state by signaling through the conserved Notch pathway. Downstream of Notch signaling, key regulators include novel LST-1 and SYGL-1 proteins and a network of RNA regulatory proteins. In this chapter we present methods for characterizing the C. elegans GSC pool and early germ cell differentiation. The methods include examination of the germline in living and fixed worms, cell cycle analysis, and analysis of markers. We also discuss assays to separate mutants that affect the stem cell vs. differentiation decision from those that affect germ cell processes more generally.
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Affiliation(s)
- Sarah L Crittenden
- HHMI/Department of Biochemistry, Howard Hughes Medical Institute and University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI, 53706-1544, USA.
| | - Hannah S Seidel
- HHMI/Department of Biochemistry, Howard Hughes Medical Institute and University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI, 53706-1544, USA
| | - Judith Kimble
- HHMI/Department of Biochemistry, Howard Hughes Medical Institute and University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI, 53706-1544, USA
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44
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Watson E, Yilmaz LS, Walhout AJM. Understanding Metabolic Regulation at a Systems Level: Metabolite Sensing, Mathematical Predictions, and Model Organisms. Annu Rev Genet 2016; 49:553-75. [PMID: 26631516 DOI: 10.1146/annurev-genet-112414-055257] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Metabolic networks are extensively regulated to facilitate tissue-specific metabolic programs and robustly maintain homeostasis in response to dietary changes. Homeostatic metabolic regulation is achieved through metabolite sensing coupled to feedback regulation of metabolic enzyme activity or expression. With a wealth of transcriptomic, proteomic, and metabolomic data available for different cell types across various conditions, we are challenged with understanding global metabolic network regulation and the resulting metabolic outputs. Stoichiometric metabolic network modeling integrated with "omics" data has addressed this challenge by generating nonintuitive, testable hypotheses about metabolic flux rewiring. Model organism studies have also yielded novel insight into metabolic networks. This review covers three topics: the feedback loops inherent in metabolic regulatory networks, metabolic network modeling, and interspecies studies utilizing Caenorhabditis elegans and various bacterial diets that have revealed novel metabolic paradigms.
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Affiliation(s)
- Emma Watson
- Program in Systems Biology, Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605; , ,
| | - L Safak Yilmaz
- Program in Systems Biology, Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605; , ,
| | - Albertha J M Walhout
- Program in Systems Biology, Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605; , ,
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45
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Sperm Affects Head Sensory Neuron in Temperature Tolerance of Caenorhabditis elegans. Cell Rep 2016; 16:56-65. [PMID: 27320929 DOI: 10.1016/j.celrep.2016.05.078] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 03/18/2016] [Accepted: 05/18/2016] [Indexed: 01/12/2023] Open
Abstract
Tolerance to environmental temperature change is essential for the survival and proliferation of animals. The process is controlled by various body tissues, but the orchestration of activity within the tissue network has not been elucidated in detail. Here, we show that sperm affects the activity of temperature-sensing neurons (ASJ) that control cold tolerance in Caenorhabditis elegans. Genetic impairment of sperm caused abnormal cold tolerance, which was unexpectedly restored by impairment of temperature signaling in ASJ neurons. Calcium imaging revealed that ASJ neuronal activity in response to temperature was decreased in sperm mutant gsp-4 with impaired protein phosphatase 1 and rescued by expressing gsp-4 in sperm. Genetic analysis revealed a feedback network in which ASJ neuronal activity regulates the intestine through insulin and a steroid hormone, which then affects sperm and, in turn, controls ASJ neuronal activity. Thus, we propose that feedback between sperm and a sensory neuron mediating temperature tolerance.
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46
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Chi C, Ronai D, Than MT, Walker CJ, Sewell AK, Han M. Nucleotide levels regulate germline proliferation through modulating GLP-1/Notch signaling in C. elegans. Genes Dev 2016; 30:307-20. [PMID: 26833730 PMCID: PMC4743060 DOI: 10.1101/gad.275107.115] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
In this study, Chi et al. researched the link between known nutrient-sensing systems and reproductive programs. Using a model system in C. elegans, they show that a Notch signaling pathway senses the level of uridine/thymidine and controls germline proliferation, delineating a previously unknown nucleotide-sensing mechanism for controlling reproductivity. Animals alter their reproductive programs to accommodate changes in nutrient availability, yet the connections between known nutrient-sensing systems and reproductive programs are underexplored, and whether there is a mechanism that senses nucleotide levels to coordinate germline proliferation is unknown. We established a model system in which nucleotide metabolism is perturbed in both the nematode Caenorhabditis elegans (cytidine deaminases) and its food (Escherichia coli); when fed food with a low uridine/thymidine (U/T) level, germline proliferation is arrested. We provide evidence that this impact of U/T level on the germline is critically mediated by GLP-1/Notch and MPK-1/MAPK, known to regulate germline mitotic proliferation. This germline defect is suppressed by hyperactivation of glp-1 or disruption of genes downstream from glp-1 to promote meiosis but not by activation of the IIS or TORC1 pathways. Moreover, GLP-1 expression is post-transcriptionally modulated by U/T levels. Our results reveal a previously unknown nucleotide-sensing mechanism for controlling reproductivity.
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Affiliation(s)
- Congwu Chi
- Howard Hughes Medical Institute, Department of Molecular, Cellular, and Developmental Biology, University of Colorado at Boulder, Boulder, Colorado 80309, USA
| | - Diana Ronai
- Howard Hughes Medical Institute, Department of Molecular, Cellular, and Developmental Biology, University of Colorado at Boulder, Boulder, Colorado 80309, USA
| | - Minh T Than
- Howard Hughes Medical Institute, Department of Molecular, Cellular, and Developmental Biology, University of Colorado at Boulder, Boulder, Colorado 80309, USA
| | - Cierra J Walker
- Howard Hughes Medical Institute, Department of Molecular, Cellular, and Developmental Biology, University of Colorado at Boulder, Boulder, Colorado 80309, USA
| | - Aileen K Sewell
- Howard Hughes Medical Institute, Department of Molecular, Cellular, and Developmental Biology, University of Colorado at Boulder, Boulder, Colorado 80309, USA
| | - Min Han
- Howard Hughes Medical Institute, Department of Molecular, Cellular, and Developmental Biology, University of Colorado at Boulder, Boulder, Colorado 80309, USA
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47
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Yilmaz LS, Walhout AJM. A Caenorhabditis elegans Genome-Scale Metabolic Network Model. Cell Syst 2016; 2:297-311. [PMID: 27211857 DOI: 10.1016/j.cels.2016.04.012] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 03/08/2016] [Accepted: 04/15/2016] [Indexed: 11/30/2022]
Abstract
Caenorhabditis elegans is a powerful model to study metabolism and how it relates to nutrition, gene expression, and life history traits. However, while numerous experimental techniques that enable perturbation of its diet and gene function are available, a high-quality metabolic network model has been lacking. Here, we reconstruct an initial version of the C. elegans metabolic network. This network model contains 1,273 genes, 623 enzymes, and 1,985 metabolic reactions and is referred to as iCEL1273. Using flux balance analysis, we show that iCEL1273 is capable of representing the conversion of bacterial biomass into C. elegans biomass during growth and enables the predictions of gene essentiality and other phenotypes. In addition, we demonstrate that gene expression data can be integrated with the model by comparing metabolic rewiring in dauer animals versus growing larvae. iCEL1273 is available at a dedicated website (wormflux.umassmed.edu) and will enable the unraveling of the mechanisms by which different macro- and micronutrients contribute to the animal's physiology.
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Affiliation(s)
- L Safak Yilmaz
- Programs in Systems Biology and Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA.
| | - Albertha J M Walhout
- Programs in Systems Biology and Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA.
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48
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Yen CA, Curran SP. Gene-diet interactions and aging in C. elegans. Exp Gerontol 2016; 86:106-112. [PMID: 26924670 DOI: 10.1016/j.exger.2016.02.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 02/16/2016] [Accepted: 02/24/2016] [Indexed: 02/06/2023]
Abstract
Diet is the most variable aspect of life history, as most individuals have a large diversity of food choices, varying in the type and amount that they ingest. In the short-term, diet can affect metabolism and energy levels. However, in the long run, the net deficiency or excess of calories from diet can influence the progression and severity of age-related diseases. An old and yet still debated question is: how do specific dietary choices impact health- and lifespan? It is clear that genetics can play a critical role - perhaps just as important as diet choices. For example, poor diet in combination with genetic susceptibility can lead to metabolic disorders, such as obesity and type 2 diabetes. Recent work in Caenorhabditis elegans has identified the existence of diet-gene pairs, where the consequence of mutating a specific gene is only realized on specific diets. Many core metabolic pathways are conserved from worm to human. Although only a handful of these diet-gene pairs has been characterized, there are potentially hundreds, if not thousands, of such interactions, which may explain the variability in the rates of aging in humans and the incidence and severity of age-related diseases.
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Affiliation(s)
- Chia An Yen
- University of Southern California, Dornsife College of Letters, Arts, and Science, Department of Molecular and Computational Biology, United States
| | - Sean P Curran
- University of Southern California, Dornsife College of Letters, Arts, and Science, Department of Molecular and Computational Biology, United States; University of Southern California, Davis School of Gerontology, United States.
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49
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MacNeil LT, Pons C, Arda HE, Giese GE, Myers CL, Walhout AJM. Transcription Factor Activity Mapping of a Tissue-Specific in vivo Gene Regulatory Network. Cell Syst 2015; 1:152-162. [PMID: 26430702 DOI: 10.1016/j.cels.2015.08.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
A wealth of physical interaction data between transcription factors (TFs) and DNA has been generated, but these interactions often do not have apparent regulatory consequences. Thus, equating physical interaction data with gene regulatory networks (GRNs) is problematic. Here, we comprehensively assay TF activity, rather than binding, to construct a network of gene regulatory interactions in the C. elegans intestine. By manually observing the in vivo tissue-specific knockdown of 921 TFs on a panel of 19 fluorescent transcriptional reporters, we identified a GRN of 411 interactions between 19 promoters and 177 TFs. This GRN shows only modest overlap with physical interactions, indicating that many regulatory interactions are indirect. We applied nested effects modeling to uncover information flow between TFs in the intestine that converges on a small set of physical TF-promoter interactions. We found numerous cell nonautonomous regulatory interactions, illustrating tissue-to-tissue communication. Altogether, our study illuminates the complexity of gene regulation in the context of a living animal.
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Affiliation(s)
- Lesley T MacNeil
- Program in Systems Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA ; Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Carles Pons
- Department of Computer Science and Engineering, University of Minnesota-Twin Cities, Minneapolis, MN 55455, USA
| | - H Efsun Arda
- Program in Systems Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA ; Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Gabrielle E Giese
- Program in Systems Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Chad L Myers
- Department of Computer Science and Engineering, University of Minnesota-Twin Cities, Minneapolis, MN 55455, USA
| | - Albertha J M Walhout
- Program in Systems Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA ; Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
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50
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RNAi Interrogation of Dietary Modulation of Development, Metabolism, Behavior, and Aging in C. elegans. Cell Rep 2015; 11:1123-33. [PMID: 25959815 DOI: 10.1016/j.celrep.2015.04.024] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 01/29/2015] [Accepted: 04/11/2015] [Indexed: 02/06/2023] Open
Abstract
Diet affects nearly every aspect of animal life such as development, metabolism, behavior, and aging, both directly by supplying nutrients and indirectly through gut microbiota. C. elegans feeds on bacteria, and like other animals, different bacterial diets induce distinct dietary responses in the worm. However, the lack of certain critical tools hampers the use of worms as a model for dietary signaling. Here, we genetically engineered the bacterial strain OP50, the standard laboratory diet for C. elegans, making it compatible for dsRNA production and delivery. Using this RNAi-compatible OP50 strain and the other bacterial strain HT115, we feed worms different diets while delivering RNAi to interrogate the genetic basis underlying diet-dependent differential modulation of development, metabolism, behavior, and aging. We show by RNAi that neuroendocrine and mTOR pathways are involved in mediating differential dietary responses. This genetic tool greatly facilitates the use of C. elegans as a model for dietary signaling.
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