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How CM, Li YS, Huang WY, Wei CC. Early-life exposure to mycotoxin zearalenone exacerbates aberrant immune response, oxidative stress, and mortality of Caenorhabditis elegans under pathogen Bacillus thuringiensis infection. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 272:116085. [PMID: 38342010 DOI: 10.1016/j.ecoenv.2024.116085] [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: 11/05/2023] [Revised: 01/31/2024] [Accepted: 02/06/2024] [Indexed: 02/13/2024]
Abstract
Zearalenone (ZEN) is a prevalent mycotoxin that severely impacts human and animal health. However, the possible interactions between ZEN exposure, pathogen infection, immune system, and reactive oxygen species (ROS) were rarely investigated. We studied the effects of early-life ZEN (50 µM) exposure on the immune response of Caenorhabditis elegans against Bacillus thuringiensis infection and the associated mechanisms. The transcriptomic responses of C. elegans after early-life ZEN exposure were investigated using RNA sequencing and followed by verification using quantitative PCR analysis. We also investigated the immune responses of the worms through B. thuringiensis killing assays and by measuring oxidative stress. The transcriptomics result showed that early-life exposure to ZEN resulted in 44 differentially expressed genes, 7 of which were protein-coding genes with unknown functions. The Gene Ontology analysis suggested that metabolic processes and immune response were among the most significantly enriched biological processes, and the KEGG analysis suggested that lysosomes and metabolic pathways were the most significantly enriched pathways. The ZEN-exposed worms exhibited significantly reduced survival after 24-h B. thuringiensis infection, reaching near 100% mortality compared to 60% of the controls. Using qRT-PCR assay, we found that ZEN further enhanced the expression of immunity genes lys-6, spp-1, and clec-60 after B. thuringiensis infection. A concurrently enhanced ROS accumulation was also observed for ZEN-exposed worms after B. thuringiensis infection, which was 1.2-fold compared with the controls. Moreover, ZEN exposure further enhanced mRNA expression of catalases (ctl-1 and ctl-2) and increased catalase protein activity after B. thuringiensis exposure compared with their non-exposed counterparts, suggesting an elevated oxidative stress. This study suggests that early-life exposure to mycotoxin zearalenone overstimulates immune responses involving spp-17, clec-52, and clec-56, resulting in excessive ROS production, enhanced oxidative stress as indicated by aggravated ctl expression and activity, and a decline in host resistance to pathogenic infection which ultimately leads to increased mortality under B. thuringiensis infection. Our findings provide evidence that could improve our understanding on the potential interactions between mycotoxin zearalenone and pathogens.
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Affiliation(s)
- Chun Ming How
- Institute of Food Safety and Health, College of Public Health, National Taiwan University, Taipei 10055, Taiwan
| | - Yong-Shan Li
- Institute of Food Safety and Health, College of Public Health, National Taiwan University, Taipei 10055, Taiwan
| | - Wei-Yun Huang
- Institute of Food Safety and Health, College of Public Health, National Taiwan University, Taipei 10055, Taiwan
| | - Chia-Cheng Wei
- Institute of Food Safety and Health, College of Public Health, National Taiwan University, Taipei 10055, Taiwan; Department of Public Health, College of Public Health, National Taiwan University, Taipei 10055, Taiwan.
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2
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Griem-Krey H, Petersen C, Hamerich IK, Schulenburg H. The intricate triangular interaction between protective microbe, pathogen and host determines fitness of the metaorganism. Proc Biol Sci 2023; 290:20232193. [PMID: 38052248 PMCID: PMC10697802 DOI: 10.1098/rspb.2023.2193] [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: 09/26/2023] [Accepted: 11/07/2023] [Indexed: 12/07/2023] Open
Abstract
The microbiota shapes host biology in numerous ways. One example is protection against pathogens, which is likely critical for host fitness in consideration of the ubiquity of pathogens. The host itself can affect abundance of microbiota or pathogens, which has usually been characterized in separate studies. To date, however, it is unclear how the host influences the interaction with both simultaneously and how this triangular interaction determines fitness of the host-microbe assemblage, the so-called metaorganism. To address this current knowledge gap, we focused on a triangular model interaction, consisting of the nematode Caenorhabditis elegans, its protective symbiont Pseudomonas lurida MYb11 and its pathogen Bacillus thuringiensis Bt679. We combined the two microbes with C. elegans mutants with altered immunity and/or microbial colonization, and found that (i) under pathogen stress, immunocompetence has a larger influence on metaorganism fitness than colonization with the protective microbe; (ii) in almost all cases, MYb11 still improves fitness; and (iii) disruption of p38 MAPK signalling, which contributes centrally to immunity against Bt679, completely reverses the protective effect of MYb11, which further reduces nematode survival and fitness upon infection with Bt679. Our study highlights the complex interplay between host, protective microbe and pathogen in shaping metaorganism biology.
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Affiliation(s)
- Hanne Griem-Krey
- Department of Evolutionary Ecology and Genetics, Kiel University, Kiel 24118, Germany
| | - Carola Petersen
- Department of Evolutionary Ecology and Genetics, Kiel University, Kiel 24118, Germany
| | - Inga K. Hamerich
- Department of Evolutionary Ecology and Genetics, Kiel University, Kiel 24118, Germany
| | - Hinrich Schulenburg
- Department of Evolutionary Ecology and Genetics, Kiel University, Kiel 24118, Germany
- Antibiotic resistance group, Max-Planck-Institute for Evolutionary Biology, Plön, Germany
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3
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Petersen C, Hamerich IK, Adair KL, Griem-Krey H, Torres Oliva M, Hoeppner MP, Bohannan BJM, Schulenburg H. Host and microbiome jointly contribute to environmental adaptation. THE ISME JOURNAL 2023; 17:1953-1965. [PMID: 37673969 PMCID: PMC10579302 DOI: 10.1038/s41396-023-01507-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 08/25/2023] [Accepted: 08/30/2023] [Indexed: 09/08/2023]
Abstract
Most animals and plants have associated microorganisms, collectively referred to as their microbiomes, which can provide essential functions. Given their importance, host-associated microbiomes have the potential to contribute substantially to adaptation of the host-microbiome assemblage (the "metaorganism"). Microbiomes may be especially important for rapid adaptation to novel environments because microbiomes can change more rapidly than host genomes. However, it is not well understood how hosts and microbiomes jointly contribute to metaorganism adaptation. We developed a model system with which to disentangle the contributions of hosts and microbiomes to metaorganism adaptation. We established replicate mesocosms containing the nematode Caenorhabditis elegans co-cultured with microorganisms in a novel complex environment (laboratory compost). After approximately 30 nematode generations (100 days), we harvested worm populations and associated microbiomes, and subjected them to a common garden experiment designed to unravel the impacts of microbiome composition and host genetics on metaorganism adaptation. We observed that adaptation took different trajectories in different mesocosm lines, with some increasing in fitness and others decreasing, and that interactions between host and microbiome played an important role in these contrasting evolutionary paths. We chose two exemplary mesocosms (one with a fitness increase and one with a decrease) for detailed study. For each example, we identified specific changes in both microbiome composition (for both bacteria and fungi) and nematode gene expression associated with each change in fitness. Our study provides experimental evidence that adaptation to a novel environment can be jointly influenced by host and microbiome.
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Affiliation(s)
- Carola Petersen
- Department of Evolutionary Ecology and Genetics, Kiel University, Kiel, Germany
| | - Inga K Hamerich
- Department of Evolutionary Ecology and Genetics, Kiel University, Kiel, Germany
| | - Karen L Adair
- Institute of Ecology and Evolution, University of Oregon, Eugene, OR, USA
| | - Hanne Griem-Krey
- Department of Evolutionary Ecology and Genetics, Kiel University, Kiel, Germany
| | | | - Marc P Hoeppner
- Institute of Clinical Molecular Biology, Kiel University, Kiel, Germany
| | | | - Hinrich Schulenburg
- Department of Evolutionary Ecology and Genetics, Kiel University, Kiel, Germany.
- Max-Planck Institute for Evolutionary Biology, Ploen, Germany.
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4
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Wang Z, Yang W, Yin C, Ma W, Liao M, Li F, Zhang J. Cry9A and Vip3A protein-induced transcriptional changes correspond to their synergistic damage to the midgut of Chilo suppressalis. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2023; 196:105596. [PMID: 37945246 DOI: 10.1016/j.pestbp.2023.105596] [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: 06/29/2023] [Revised: 08/13/2023] [Accepted: 08/28/2023] [Indexed: 11/12/2023]
Abstract
Cry and Vip3 proteins are both pore-forming toxins produced by Bacillus thuringiensis that show synergistic insecticidal activity against different insect pests. However, the synergistic effect of Cry and Vip3 proteins on the midgut in target insects is still unclear. In this study, faster and more serious damage was observed after treatment with both Cry9A and Vip3A proteins in the Chilo suppressalis midgut compared to single-protein treatment. Through RNA sequencing, midgut transcriptomic comparison was performed between dual- and single-protein treatments according to midgut injury. After 6 h, 609 differentially expressed genes were found with the combined Cry9A and Vip3A treatments, which was much more than that in the single treatment, corresponding to faster and more serious damage. These genes were mainly enriched in similar pathways, such as lipid metabolic, oxidation-reduction and carbohydrate metabolic process, peptide secretion and cell-cell adhesion; however, the number and expression level of differentially expressed genes are increased. For specific genes significantly regulated by induction of Cry9A and Vip3A, lipases, phospholipid scramblase, probable tape measure protein and arylsulfatase J were significantly downregulated after 6 h treatment. In addition, regular genes related to the activation and receptor binding of B. thuringiensis toxins were differentially regulated, such as ATP-binding cassette subfamily G member 1 and serine protease. Validation with RT-qPCR showed agreement with the sequencing results. Overall, our results support that stronger and faster midgut responses at the cellular and transcriptional levels are induced by the synergistic toxicity of Cry9A and Vip3A in C. suppressalis.
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Affiliation(s)
- Zeyu Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Wenquan Yang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; School of Plant Protection, Anhui Agricultural University, Hefei 230036, China
| | - Chuanlin Yin
- State Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insect Pests, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China
| | - Weihua Ma
- National Key Laboratory of Crop Genetic Improvement, National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan 430070, China
| | - Min Liao
- School of Plant Protection, Anhui Agricultural University, Hefei 230036, China
| | - Fei Li
- State Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insect Pests, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China
| | - Jie Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; School of Plant Protection, Anhui Agricultural University, Hefei 230036, China.
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Williams RTP, King DC, Mastroianni IR, Hill JL, Apenes NW, Ramirez G, Miner EC, Moore A, Coleman K, Nishimura EO. Transcriptome profiling of the Caenorhabditis elegans intestine reveals that ELT-2 negatively and positively regulates intestinal gene expression within the context of a gene regulatory network. Genetics 2023; 224:iyad088. [PMID: 37183501 PMCID: PMC10411582 DOI: 10.1093/genetics/iyad088] [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: 03/06/2023] [Revised: 04/28/2023] [Accepted: 04/30/2023] [Indexed: 05/16/2023] Open
Abstract
ELT-2 is the major transcription factor (TF) required for Caenorhabditis elegans intestinal development. ELT-2 expression initiates in embryos to promote development and then persists after hatching through the larval and adult stages. Though the sites of ELT-2 binding are characterized and the transcriptional changes that result from ELT-2 depletion are known, an intestine-specific transcriptome profile spanning developmental time has been missing. We generated this dataset by performing Fluorescence Activated Cell Sorting on intestine cells at distinct developmental stages. We analyzed this dataset in conjunction with previously conducted ELT-2 studies to evaluate the role of ELT-2 in directing the intestinal gene regulatory network through development. We found that only 33% of intestine-enriched genes in the embryo were direct targets of ELT-2 but that number increased to 75% by the L3 stage. This suggests additional TFs promote intestinal transcription especially in the embryo. Furthermore, only half of ELT-2's direct target genes were dependent on ELT-2 for their proper expression levels, and an equal proportion of those responded to elt-2 depletion with over-expression as with under-expression. That is, ELT-2 can either activate or repress direct target genes. Additionally, we observed that ELT-2 repressed its own promoter, implicating new models for its autoregulation. Together, our results illustrate that ELT-2 impacts roughly 20-50% of intestine-specific genes, that ELT-2 both positively and negatively controls its direct targets, and that the current model of the intestinal regulatory network is incomplete as the factors responsible for directing the expression of many intestinal genes remain unknown.
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Affiliation(s)
- Robert T P Williams
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - David C King
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Izabella R Mastroianni
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jessica L Hill
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Nicolai W Apenes
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Gabriela Ramirez
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
- Department of Cell and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - E Catherine Miner
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
- College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
| | - Andrew Moore
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Karissa Coleman
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Erin Osborne Nishimura
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
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6
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Wan YC, Troemel ER, Reinke AW. Conservation of Nematocida microsporidia gene expression and host response in Caenorhabditis nematodes. PLoS One 2022; 17:e0279103. [PMID: 36534656 PMCID: PMC9762603 DOI: 10.1371/journal.pone.0279103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 11/30/2022] [Indexed: 12/24/2022] Open
Abstract
Microsporidia are obligate intracellular parasites that are known to infect most types of animals. Many species of microsporidia can infect multiple related hosts, but it is not known if microsporidia express different genes depending upon which host species is infected or if the host response to infection is specific to each microsporidia species. To address these questions, we took advantage of two species of Nematocida microsporidia, N. parisii and N. ausubeli, that infect two species of Caenorhabditis nematodes, C. elegans and C. briggsae. We performed RNA-seq at several time points for each host infected with either microsporidia species. We observed that Nematocida transcription was largely independent of its host. We also observed that the host transcriptional response was similar when infected with either microsporidia species. Finally, we analyzed if the host response to microsporidia infection was conserved across host species. We observed that although many of the genes upregulated in response to infection are not direct orthologs, the same expanded gene families are upregulated in both Caenorhabditis hosts. Together our results describe the transcriptional interactions of Nematocida infection in Caenorhabditis hosts and demonstrate that these responses are evolutionarily conserved.
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Affiliation(s)
- Yin Chen Wan
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Emily R. Troemel
- School of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - Aaron W. Reinke
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada,* E-mail:
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Bhat CG, Budhwar R, Godwin J, Dillman AR, Rao U, Somvanshi VS. RNA-Sequencing of Heterorhabditis nematodes to identify factors involved in symbiosis with Photorhabdus bacteria. BMC Genomics 2022; 23:741. [PMCID: PMC9639317 DOI: 10.1186/s12864-022-08952-4] [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: 08/08/2022] [Accepted: 10/07/2022] [Indexed: 11/09/2022] Open
Abstract
Background Nematodes are a major group of soil inhabiting organisms. Heterorhabditis nematodes are insect-pathogenic nematodes and live in a close symbiotic association with Photorhabdus bacteria. Heterorhabditis-Photorhabdus pair offers a powerful and genetically tractable model to study animal-microbe symbiosis. It is possible to generate symbiont bacteria free (axenic) stages in Heterorhabditis. Here, we compared the transcriptome of symbiotic early-adult stage Heterorhabditis nematodes with axenic early-adult nematodes to determine the nematode genes and pathways involved in symbiosis with Photorhabdus bacteria. Results A de-novo reference transcriptome assembly of 95.7 Mb was created for H. bacteriophora by using all the reads. The assembly contained 46,599 transcripts with N50 value of 2,681 bp and the average transcript length was 2,054 bp. The differentially expressed transcripts were identified by mapping reads from symbiotic and axenic nematodes to the reference assembly. A total of 754 differentially expressed transcripts were identified in symbiotic nematodes as compared to the axenic nematodes. The ribosomal pathway was identified as the most affected among the differentially expressed transcripts. Additionally, 12,151 transcripts were unique to symbiotic nematodes. Endocytosis, cAMP signalling and focal adhesion were the top three enriched pathways in symbiotic nematodes, while a large number of transcripts coding for various responses against bacteria, such as bacterial recognition, canonical immune signalling pathways, and antimicrobial effectors could also be identified. Conclusions The symbiotic Heterorhabditis nematodes respond to the presence of symbiotic bacteria by expressing various transcripts involved in a multi-layered immune response which might represent non-systemic and evolved localized responses to maintain mutualistic bacteria at non-threatening levels. Subject to further functional validation of the identified transcripts, our findings suggest that Heterorhabditis nematode immune system plays a critical role in maintenance of symbiosis with Photorhabdus bacteria. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-022-08952-4.
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Affiliation(s)
- Chaitra G. Bhat
- grid.418196.30000 0001 2172 0814Division of Nematology, ICAR-Indian Agricultural Research Institute, New Delhi, Delhi, 110012 India
| | - Roli Budhwar
- Bionivid Technology Private Limited, 209, 4th Cross Rd., B. Channasandra, Kasturi Nagar, Bengaluru, Karnataka 560043 India
| | - Jeffrey Godwin
- Bionivid Technology Private Limited, 209, 4th Cross Rd., B. Channasandra, Kasturi Nagar, Bengaluru, Karnataka 560043 India
| | - Adler R. Dillman
- grid.266097.c0000 0001 2222 1582Department of Nematology, University of California, Riverside, 92521 USA
| | - Uma Rao
- grid.418196.30000 0001 2172 0814Division of Nematology, ICAR-Indian Agricultural Research Institute, New Delhi, Delhi, 110012 India
| | - Vishal S. Somvanshi
- grid.418196.30000 0001 2172 0814Division of Nematology, ICAR-Indian Agricultural Research Institute, New Delhi, Delhi, 110012 India
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Ju S, Chen H, Wang S, Lin J, Ma Y, Aroian RV, Peng D, Sun M. C. elegans monitor energy status via the AMPK pathway to trigger innate immune responses against bacterial pathogens. Commun Biol 2022; 5:643. [PMID: 35773333 PMCID: PMC9246835 DOI: 10.1038/s42003-022-03589-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 06/15/2022] [Indexed: 11/13/2022] Open
Abstract
Pathogen recognition and the triggering of host innate immune system are critical to understanding pathogen-host interaction. Cellular surveillance systems have been identified as an important strategy for the identification of microbial infection. In the present study, using Bacillus thuringiensis-Caenorhabditis elegans as a model, we found an approach for surveillance systems to sense pathogens. We report that Bacillus thuringiensis Cry5Ba, a typical pore-forming toxin, caused mitochondrial damage and energy imbalance by triggering potassium ion leakage, instead of directly targeting mitochondria. Interestingly, we find C. elegans can monitor intracellular energy status to trigger innate immune responses via AMP-activated protein kinase (AMPK), secreting multiple effectors to defend against pathogenic attacks. Our study indicates that the imbalance of energy status is a prevalent side effect of pathogen infection. Furthermore, the AMPK-dependent surveillance system may serve as a practicable strategy for the host to recognize and defense against pathogens. Bacillus thuringiensis toxin Cry5Ba triggers potassium ion leakage, causing mitochondrial damage and energy imbalance. C. elegans can monitor this intracellular energy imbalance via AMP-activated protein kinase to trigger innate immune responses.
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Affiliation(s)
- Shouyong Ju
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, National Engineering Research Center of Microbial Pesticides, Huazhong Agricultural University, Wuhan, 430070, China
| | - Hanqiao Chen
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, National Engineering Research Center of Microbial Pesticides, Huazhong Agricultural University, Wuhan, 430070, China
| | - Shaoying Wang
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, National Engineering Research Center of Microbial Pesticides, Huazhong Agricultural University, Wuhan, 430070, China
| | - Jian Lin
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, National Engineering Research Center of Microbial Pesticides, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yanli Ma
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, National Engineering Research Center of Microbial Pesticides, Huazhong Agricultural University, Wuhan, 430070, China
| | - Raffi V Aroian
- Program in Molecular Medicine, University of Massachusetts Chan Medical School Worcester, Worcester, MA, 01605-2377, USA
| | - Donghai Peng
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, National Engineering Research Center of Microbial Pesticides, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Ming Sun
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, National Engineering Research Center of Microbial Pesticides, Huazhong Agricultural University, Wuhan, 430070, China.
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Camacho J, de Conti A, Pogribny IP, Sprando RL, Hunt PR. Assessment of the Effects of Organic vs. Inorganic Arsenic and Mercury in Caenorhabditis elegans. Curr Res Toxicol 2022; 3:100071. [PMID: 35602005 PMCID: PMC9118485 DOI: 10.1016/j.crtox.2022.100071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 03/26/2022] [Accepted: 04/20/2022] [Indexed: 01/03/2023] Open
Abstract
Similar developmental delays and oxidative stress with 20x DMA relative to NaAsO2. Dissimilar gene expression and locomotion with organic vs. inorganic mercury. Dissimilar unfolded protein responses for organic vs. inorganic arsenic and mercury. Across phyla, methylation has opposite effects on arsenic vs. mercury toxicity.
Exposures to mercury and arsenic are known to pose significant threats to human health. Effects specific to organic vs. inorganic forms of these toxic elements are less understood however, especially for organic dimethylarsinic acid (DMA), which has recently been detected in pups of rodent dams orally exposed to inorganic sodium (meta)arsenite (NaAsO2). Caenorhabditis elegans is a small animal alternative toxicity model. To fill data gaps on the effects of DMA relative to NaAsO2, C. elegans were exposed to these two compounds alongside more thoroughly researched inorganic mercury chloride (HgCl2) and organic methylmercury chloride (meHgCl). For timing of developmental milestone acquisition in C. elegans, meHgCl was 2 to 4-fold more toxic than HgCl2, and NaAsO2 was 20-fold more toxic than DMA, ranking the four compounds meHgCl > HgCl2 > NaAsO2 ≫ DMA for developmental toxicity. Methylmercury induced significant decreases in population locomotor activity levels in developing C. elegans. DMA was also associated with developmental hypoactivity, but at >100-fold higher concentrations than meHgCl. Transcriptional alterations in native genes were observed in wild type C. elegans adults exposed to concentrations equitoxic for developmental delay in juveniles. Both forms of arsenic induced genes involved in immune defense and oxidative stress response, while the two mercury species induced proportionally more genes involved in transcriptional regulation. A transgenic bioreporter for activation of conserved proteosome specific unfolded protein response was strongly activated by NaAsO2, but not DMA at tested concentrations. HgCl2 and meHgCl had opposite effects on a bioreporter for unfolded protein response in the endoplasmic reticulum. Presented experiments indicating low toxicity for DMA in C. elegans are consistent with human epidemiologic data correlating higher arsenic methylation capacity with resistance to arsenic toxicity. This work contributes to the understanding of the accuracy and fit-for-use categories for C. elegans toxicity screening and its usefulness to prioritize compounds of concern for further testing.
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Affiliation(s)
- Jessica Camacho
- Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Applied Research and Safety Assessment, 8301 Muirkirk Road, Laurel, MD 20708, United States
| | - Aline de Conti
- Food and Drug Administration, National Center for Toxicological Research, 3900 NCTR Rd, Jefferson, AR 72079, United States
| | - Igor P. Pogribny
- Food and Drug Administration, National Center for Toxicological Research, 3900 NCTR Rd, Jefferson, AR 72079, United States
| | - Robert L. Sprando
- Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Applied Research and Safety Assessment, 8301 Muirkirk Road, Laurel, MD 20708, United States
| | - Piper Reid Hunt
- Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Applied Research and Safety Assessment, 8301 Muirkirk Road, Laurel, MD 20708, United States
- Corresponding author.
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Kissoyan KAB, Peters L, Giez C, Michels J, Pees B, Hamerich IK, Schulenburg H, Dierking K. Exploring Effects of C. elegans Protective Natural Microbiota on Host Physiology. Front Cell Infect Microbiol 2022; 12:775728. [PMID: 35237530 PMCID: PMC8884406 DOI: 10.3389/fcimb.2022.775728] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 01/14/2022] [Indexed: 11/29/2022] Open
Abstract
The Caenorhabditis elegans natural microbiota was described only recently. Thus, our understanding of its effects on nematode physiology is still in its infancy. We previously showed that the C. elegans natural microbiota isolates Pseudomonas lurida MYb11 and P. fluorescens MYb115 protect the worm against pathogens such as Bacillus thuringiensis (Bt). However, the overall effects of the protective microbiota on worm physiology are incompletely understood. Here, we investigated how MYb11 and MYb115 affect C. elegans lifespan, fertility, and intestinal colonization. We further studied the capacity of MYb11 and MYb115 to protect the worm against purified Bt toxins. We show that while MYb115 and MYb11 affect reproductive timing and increase early reproduction only MYb11 reduces worm lifespan. Moreover, MYb11 aggravates killing upon toxin exposure. We conclude that MYb11 has a pathogenic potential in some contexts. This work thus highlights that certain C. elegans microbiota members can be beneficial and costly to the host in a context-dependent manner, blurring the line between good and bad.
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Wibisono P, Wibisono S, Watteyne J, Chen CH, Sellegounder D, Beets I, Liu Y, Sun J. Neuronal GPCR NMUR-1 regulates distinct immune responses to different pathogens. Cell Rep 2022; 38:110321. [PMID: 35139379 PMCID: PMC8869846 DOI: 10.1016/j.celrep.2022.110321] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 11/21/2021] [Accepted: 01/10/2022] [Indexed: 12/29/2022] Open
Abstract
A key question in current immunology is how the innate immune system generates high levels of specificity. Using the Caenorhabditis elegans model system, we demonstrate that functional loss of NMUR-1, a neuronal G-protein-coupled receptor homologous to mammalian receptors for the neuropeptide neuromedin U, has diverse effects on C. elegans innate immunity against various bacterial pathogens. Transcriptomic analyses and functional assays reveal that NMUR-1 modulates C. elegans transcription activity by regulating the expression of transcription factors involved in binding to RNA polymerase II regulatory regions, which, in turn, controls the expression of distinct immune genes in response to different pathogens. These results uncover a molecular basis for the specificity of C. elegans innate immunity. Given the evolutionary conservation of NMUR-1 signaling in immune regulation across multicellular organisms, our study could provide mechanistic insights into understanding the specificity of innate immunity in other animals, including mammals.
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Affiliation(s)
- Phillip Wibisono
- Department of Translational Medicine and Physiology, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, USA
| | - Shawndra Wibisono
- Department of Translational Medicine and Physiology, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, USA
| | - Jan Watteyne
- Department of Biology, KU Leuven, Leuven, Belgium
| | - Chia-Hui Chen
- Department of Translational Medicine and Physiology, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, USA
| | - Durai Sellegounder
- Department of Translational Medicine and Physiology, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, USA
| | - Isabel Beets
- Department of Biology, KU Leuven, Leuven, Belgium
| | - Yiyong Liu
- Department of Translational Medicine and Physiology, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, USA; Genomics Core, Washington State University, Spokane, WA, USA.
| | - Jingru Sun
- Department of Translational Medicine and Physiology, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, USA.
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12
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Papkou A, Schalkowski R, Barg MC, Koepper S, Schulenburg H. Population size impacts host-pathogen coevolution. Proc Biol Sci 2021; 288:20212269. [PMID: 34905713 PMCID: PMC8670963 DOI: 10.1098/rspb.2021.2269] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 11/18/2021] [Indexed: 11/25/2022] Open
Abstract
Ongoing host-pathogen interactions are characterized by rapid coevolutionary changes forcing species to continuously adapt to each other. The interacting species are often defined by finite population sizes. In theory, finite population size limits genetic diversity and compromises the efficiency of selection owing to genetic drift, in turn constraining any rapid coevolutionary responses. To date, however, experimental evidence for such constraints is scarce. The aim of our study was to assess to what extent population size influences the dynamics of host-pathogen coevolution. We used Caenorhabditus elegans and its pathogen Bacillus thuringiensis as a model for experimental coevolution in small and large host populations, as well as in host populations which were periodically forced through a bottleneck. By carefully controlling host population size for 23 host generations, we found that host adaptation was constrained in small populations and to a lesser extent in the bottlenecked populations. As a result, coevolution in large and small populations gave rise to different selection dynamics and produced different patterns of host-pathogen genotype-by-genotype interactions. Our results demonstrate a major influence of host population size on the ability of the antagonists to co-adapt to each other, thereby shaping the dynamics of antagonistic coevolution.
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Affiliation(s)
- Andrei Papkou
- Department of Evolutionary Ecology and Genetics, Zoological Institute, Christian-Albrechts-Universitaet Kiel, 24098 Kiel, Germany
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Rebecca Schalkowski
- Department of Evolutionary Ecology and Genetics, Zoological Institute, Christian-Albrechts-Universitaet Kiel, 24098 Kiel, Germany
| | - Mike-Christoph Barg
- Department of Evolutionary Ecology and Genetics, Zoological Institute, Christian-Albrechts-Universitaet Kiel, 24098 Kiel, Germany
| | - Svenja Koepper
- Department of Evolutionary Ecology and Genetics, Zoological Institute, Christian-Albrechts-Universitaet Kiel, 24098 Kiel, Germany
| | - Hinrich Schulenburg
- Department of Evolutionary Ecology and Genetics, Zoological Institute, Christian-Albrechts-Universitaet Kiel, 24098 Kiel, Germany
- Max-Planck Institute for Evolutionary Biology, 24306 Plön, Germany
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13
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Zárate-Potes A, Yang W, Andresen B, Nakad R, Haase D, Rosenstiel P, Dierking K, Schulenburg H. The effects of nested miRNAs and their host genes on immune defense against Bacillus thuringiensis infection in Caenorhabditis elegans. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2021; 123:104144. [PMID: 34051205 DOI: 10.1016/j.dci.2021.104144] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 05/20/2021] [Accepted: 05/23/2021] [Indexed: 06/12/2023]
Abstract
microRNAs (miRNAs) are small non-coding RNA-molecules that influence translation by binding to the target gene mRNA. Many miRNAs are found in nested arrangements within larger protein-coding host genes. miRNAs and host genes in a nested arrangement are often transcribed simultaneously, which may indicate that both have similar functions. miRNAs have been implicated in regulating defense responses against pathogen infection in C. elegans and in mammals. Here, we asked if miRNAs in nested arrangements and their host genes are involved in the C. elegans response against infection with Bacillus thuringiensis (Bt). We performed miRNA sequencing and subsequently focused on four nested miRNA-host gene arrangements for a functional genetic analysis. We identified mir-58.1 and mir-2 as negative regulators of C. elegans resistance to Bt infection. However, we did not find any miRNA/host gene pair in which both contribute to defense against Bt.
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Affiliation(s)
- Alejandra Zárate-Potes
- Department of Evolutionary Ecology and Genetics, Christian-Albrechts-Universität zu Kiel, Am Botanischen Garten 1-9, 24118, Kiel, Germany
| | - Wentao Yang
- Department of Evolutionary Ecology and Genetics, Christian-Albrechts-Universität zu Kiel, Am Botanischen Garten 1-9, 24118, Kiel, Germany
| | - Bentje Andresen
- Department of Evolutionary Ecology and Genetics, Christian-Albrechts-Universität zu Kiel, Am Botanischen Garten 1-9, 24118, Kiel, Germany
| | - Rania Nakad
- Department of Evolutionary Ecology and Genetics, Christian-Albrechts-Universität zu Kiel, Am Botanischen Garten 1-9, 24118, Kiel, Germany
| | - Daniela Haase
- Department of Evolutionary Ecology and Genetics, Christian-Albrechts-Universität zu Kiel, Am Botanischen Garten 1-9, 24118, Kiel, Germany
| | - Philip Rosenstiel
- Institute for Clinical Molecular Biology (IKMB), Christian-Albrechts-Universität zu Kiel, Am Botanischen Garten 1-9, 24118, Kiel, Germany
| | - Katja Dierking
- Department of Evolutionary Ecology and Genetics, Christian-Albrechts-Universität zu Kiel, Am Botanischen Garten 1-9, 24118, Kiel, Germany.
| | - Hinrich Schulenburg
- Department of Evolutionary Ecology and Genetics, Christian-Albrechts-Universität zu Kiel, Am Botanischen Garten 1-9, 24118, Kiel, Germany; Max Planck Institute for Evolutionary Biology, 24306, Ploen, Germany.
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14
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Pees B, Yang W, Kloock A, Petersen C, Peters L, Fan L, Friedrichsen M, Butze S, Zárate-Potes A, Schulenburg H, Dierking K. Effector and regulator: Diverse functions of C. elegans C-type lectin-like domain proteins. PLoS Pathog 2021; 17:e1009454. [PMID: 33793670 PMCID: PMC8051790 DOI: 10.1371/journal.ppat.1009454] [Citation(s) in RCA: 15] [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: 07/11/2020] [Revised: 04/16/2021] [Accepted: 03/05/2021] [Indexed: 11/22/2022] Open
Abstract
In C. elegans, 283 clec genes encode a highly diverse family of C-type lectin-like domain (CTLD) proteins. Since vertebrate CTLD proteins have characterized functions in defense responses against pathogens and since expression of C. elegans clec genes is pathogen-dependent, it is generally assumed that clec genes function in C. elegans immune defenses. However, little is known about the relative contribution and exact function of CLEC proteins in C. elegans immunity. Here, we focused on the C. elegans clec gene clec-4, whose expression is highly upregulated by pathogen infection, and its paralogs clec-41 and clec-42. We found that, while mutation of clec-4 resulted in enhanced resistance to the Gram-positive pathogen Bacillus thuringiensis MYBt18247 (Bt247), inactivation of clec-41 and clec-42 by RNAi enhanced susceptibility to Bt247. Further analyses revealed that enhanced resistance of clec-4 mutants to Bt247 was due to an increase in feeding cessation on the pathogen and consequently a decrease in pathogen load. Moreover, clec-4 mutants exhibited feeding deficits also on non-pathogenic bacteria that were in part reflected in the clec-4 gene expression profile, which overlapped with gene sets affected by starvation or mutation in nutrient sensing pathways. However, loss of CLEC-4 function only mildly affected life-history traits such as fertility, indicating that clec-4 mutants are not subjected to dietary restriction. While CLEC-4 function appears to be associated with the regulation of feeding behavior, we show that CLEC-41 and CLEC-42 proteins likely function as bona fide immune effector proteins that have bacterial binding and antimicrobial capacities. Together, our results exemplify functional diversification within clec gene paralogs. C-type lectin-like domain (CTLD) containing proteins fulfill various and fundamental tasks in the human and mouse immune system. Genes encoding CTLD proteins are present in all animal genomes, in some cases in very large numbers and highly diversified. While the function of several vertebrate CTLD proteins is well characterized, experimental evidence of an immune function of most invertebrate CTLD proteins is missing, although their role in immunity is usually assumed. We here explore the immune function of three related CTLD proteins in the model nematode Caenorhabditis elegans. We find that they play diverse roles in C. elegans immunity, functioning as antimicrobial immune effector proteins that are important for defense against pathogen infection and probably directly interact with bacteria, but also regulators of feeding behavior that more indirectly affect C. elegans pathogen resistance. Such insight into the functional consequence of invertebrate CTLD protein diversification contributes to our understanding of the evolution of innate and invertebrate immune systems.
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Affiliation(s)
- Barbara Pees
- Department of Evolutionary Ecology and Genetics, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
- Department of Comparative Immunobiology, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Wentao Yang
- Department of Evolutionary Ecology and Genetics, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Anke Kloock
- Department of Evolutionary Ecology and Genetics, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Carola Petersen
- Department of Evolutionary Ecology and Genetics, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
- Department of Comparative Immunobiology, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Lena Peters
- Department of Evolutionary Ecology and Genetics, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Li Fan
- Department of Evolutionary Ecology and Genetics, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Meike Friedrichsen
- Department of Evolutionary Ecology and Genetics, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Sabrina Butze
- Department of Evolutionary Ecology and Genetics, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Alejandra Zárate-Potes
- Department of Evolutionary Ecology and Genetics, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Hinrich Schulenburg
- Department of Evolutionary Ecology and Genetics, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
- Max-Planck Institute for Evolutionary Biology, Ploen, Germany
| | - Katja Dierking
- Department of Evolutionary Ecology and Genetics, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
- * E-mail:
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15
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Take a Walk to the Wild Side of Caenorhabditis elegans-Pathogen Interactions. Microbiol Mol Biol Rev 2021; 85:85/2/e00146-20. [PMID: 33731489 DOI: 10.1128/mmbr.00146-20] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Microbiomes form intimate functional associations with their hosts. Much has been learned from correlating changes in microbiome composition to host organismal functions. However, in-depth functional studies require the manipulation of microbiome composition coupled with the precise interrogation of organismal physiology-features available in few host study systems. Caenorhabditis elegans has proven to be an excellent genetic model organism to study innate immunity and, more recently, microbiome interactions. The study of C. elegans-pathogen interactions has provided in depth understanding of innate immune pathways, many of which are conserved in other animals. However, many bacteria were chosen for these studies because of their convenience in the lab setting or their implication in human health rather than their native interactions with C. elegans In their natural environment, C. elegans feed on a variety of bacteria found in rotting organic matter, such as rotting fruits, flowers, and stems. Recent work has begun to characterize the native microbiome and has identified a common set of bacteria found in the microbiome of C. elegans While some of these bacteria are beneficial to C. elegans health, others are detrimental, leading to a complex, multifaceted understanding of bacterium-nematode interactions. Current research on nematode-bacterium interactions is focused on these native microbiome components, both their interactions with each other and with C. elegans We will summarize our knowledge of bacterial pathogen-host interactions in C. elegans, as well as recent work on the native microbiome, and explore the incorporation of these bacterium-nematode interactions into studies of innate immunity and pathogenesis.
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Abstract
In its natural habitat, C. elegans encounters a wide variety of microbes, including food, commensals and pathogens. To be able to survive long enough to reproduce, C. elegans has developed a complex array of responses to pathogens. These activities are coordinated on scales that range from individual organelles to the entire organism. Often, the response is triggered within cells, by detection of infection-induced damage, mainly in the intestine or epidermis. C. elegans has, however, a capacity for cell non-autonomous regulation of these responses. This frequently involves the nervous system, integrating pathogen recognition, altering host biology and governing avoidance behavior. Although there are significant differences with the immune system of mammals, some mechanisms used to limit pathogenesis show remarkable phylogenetic conservation. The past 20 years have witnessed an explosion of host-pathogen interaction studies using C. elegans as a model. This review will discuss the broad themes that have emerged and highlight areas that remain to be fully explored.
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Affiliation(s)
- Céline N Martineau
- Aix Marseille Université, Inserm, CNRS, CIML, Turing Centre for Living Systems, Marseille, France
| | | | - Nathalie Pujol
- Aix Marseille Université, Inserm, CNRS, CIML, Turing Centre for Living Systems, Marseille, France.
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