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Mallick S, Mishra N, Barik BK, Negi VD. Salmonella Typhimurium fepB negatively regulates C. elegans behavioral plasticity. J Infect 2022; 84:518-530. [PMID: 34990707 DOI: 10.1016/j.jinf.2021.12.043] [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: 09/04/2021] [Revised: 12/27/2021] [Accepted: 12/29/2021] [Indexed: 10/19/2022]
Abstract
OBJECTIVES Dauer is an alternative developmental stage of Caenorhabditis elegans (C. elegans) that gives survival benefits under unfavorable environmental conditions. Our study aims to decipher C. elegans dauer larvae development upon Salmonella Typhimurium infection and how the bacterial gene regulating the worm's behavioural plasticity for better survival. METHODS Age-synchronized L4 C. elegans worms were infected with Salmonella Typhimurium 14028s (WT-STM) strain and mutant strains to check the dauer larvae development using 1% SDS. Besides, bacterial load in animals' gut, pharyngeal pumping rate and viability were checked. Worm's immune genes (e.g., ilys-3, lys-7, pmk-1, abf-2, clec-60) and dauer regulatory genes (e.g., daf-7, daf-11, daf-12, daf-16, daf-3) were checked by performing qRT-PCR under infection conditions. RESULTS We found that deletion of the fepB gene in S. Typhimurium strain became less pathogenic with reduced flagellar motility and biofilm-forming ability. Besides, there was decreased bacterial burden in the worm's gut with no damage to their pharynx. The fepB mutant strain was also able to enhance the immune responses for better survival of worms. Infection with mutant strain could activate dauer signaling via the TGF-β pathway leading to a significant increase in dauer formation than WT-STM infection. CONCLUSION Our study indicated that the bacteria act as a food source for the growth of C. elegans and development and can act as a signal that might be playing an essential role in regulating the host physiology for their survival. Such a study can help us in understanding the complex host-pathogen interaction benefiting pathogen in host dissemination.
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Affiliation(s)
- Swarupa Mallick
- Laboratory of Infection Immunology, Department of Life Science, National Institute of Technology, Rourkela 769008, Odisha, India.
| | - Neha Mishra
- Laboratory of Infection Immunology, Department of Life Science, National Institute of Technology, Rourkela 769008, Odisha, India.
| | - Bedanta Kumar Barik
- Laboratory of Infection Immunology, Department of Life Science, National Institute of Technology, Rourkela 769008, Odisha, India.
| | - Vidya Devi Negi
- Laboratory of Infection Immunology, Department of Life Science, National Institute of Technology, Rourkela 769008, Odisha, India.
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2
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Wang C, Yang SH, Niu N, Tao J, Du XC, Yang JH, Zhu MX, Wang YN, Zhao W. lncRNA028466 regulates Th1/Th2 cytokine expression and associates with Echinococcus granulosus antigen P29 immunity. Parasit Vectors 2021; 14:295. [PMID: 34082780 PMCID: PMC8173744 DOI: 10.1186/s13071-021-04795-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 05/20/2021] [Indexed: 02/07/2023] Open
Abstract
Background Cystic echinococcosis (CE) is a parasitic disease that is caused by Echinococcus granulosus (Eg). The recombinant Echinococcus granulosus antigen P29 (rEg.P29) was shown to confer effective immunity to sheep and mice during E. granulosus secondary infection in our previous study. In this study, we sought to investigate the ability of long noncoding RNA 028466 (lncRNA028466) as a regulator for the protective immunity mediated by rEg.P29 vaccination and to study the effects of lncRNA028466 on CD4+T cell differentiation in mice spleen. Methods Female BALB/c mice were divided into two groups and were vaccinated subcutaneously with rEg.P29 antigen and PBS as a control (12 mice each group). Following prime-boost vaccination, CD4+T, CD8+T, and B cells from the spleen were isolated by flow cytometry. Quantitative real-time PCR (qRT-PCR) was performed to measure the expression of lncRNA028466 in these three kinds of cells. Then, lncRNA028466 was overexpressed and knocked down in naive CD4+T cells, and Th1 and Th2 cytokine expression was detected. qRT-PCR, western blot, and ELISA were performed to evaluate the production of IFN-γ, IL-2, IL-4, and IL-10, and flow cytometry was performed to detect the differentiation of Th1 and Th2 subgroups. Results lncRNA028466 was significantly decreased after the second week of immunization with rEg.P29 antigen. The proportion of CD4+ T cells was increased after rEg.P29 immunization. Overexpression of lncRNA028466 facilitated the production of IL-4, IL-10 and suppressed the production of IFN-γ, IL-2. Furthermore, after transfection with siRNA028466, IL-2 production was facilitated and IL-10 production was suppressed in naive CD4+ T cells. Conclusions Immunization with rEg.P29 downregulated the expression of lncRNA028466, which was related to a higher Th1 immune response and a lower Th2 immune response. Our results suggest that lncRNA028466 may be involved in rEg.P29-mediated immune response by regulating cytokine expression of Th1 and Th2. Supplementary Information The online version contains supplementary material available at 10.1186/s13071-021-04795-2.
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Affiliation(s)
- Chan Wang
- Department of Medical genetics and Cell biology, School of Basic Medical Science of Ningxia Medical University, Yinchuan, 750004, Ningxia Hui Autonomous Region, People's Republic of China.,Ningxia Key Laboratory of Prevention and Control of Common Infectious Diseases of Ningxia Medical University, Yinchuan, 750004, Ningxia Hui Autonomous Region, People's Republic of China
| | - Song-Hao Yang
- Department of Medical genetics and Cell biology, School of Basic Medical Science of Ningxia Medical University, Yinchuan, 750004, Ningxia Hui Autonomous Region, People's Republic of China.,Ningxia Key Laboratory of Prevention and Control of Common Infectious Diseases of Ningxia Medical University, Yinchuan, 750004, Ningxia Hui Autonomous Region, People's Republic of China
| | - Nan Niu
- Department of Medical genetics and Cell biology, School of Basic Medical Science of Ningxia Medical University, Yinchuan, 750004, Ningxia Hui Autonomous Region, People's Republic of China.,Ningxia Key Laboratory of Prevention and Control of Common Infectious Diseases of Ningxia Medical University, Yinchuan, 750004, Ningxia Hui Autonomous Region, People's Republic of China
| | - Jia Tao
- Department of Medical genetics and Cell biology, School of Basic Medical Science of Ningxia Medical University, Yinchuan, 750004, Ningxia Hui Autonomous Region, People's Republic of China.,Ningxia Key Laboratory of Prevention and Control of Common Infectious Diseases of Ningxia Medical University, Yinchuan, 750004, Ningxia Hui Autonomous Region, People's Republic of China
| | - Xian-Cai Du
- Department of Medical genetics and Cell biology, School of Basic Medical Science of Ningxia Medical University, Yinchuan, 750004, Ningxia Hui Autonomous Region, People's Republic of China.,Ningxia Key Laboratory of Prevention and Control of Common Infectious Diseases of Ningxia Medical University, Yinchuan, 750004, Ningxia Hui Autonomous Region, People's Republic of China
| | - Ji-Hui Yang
- Center of Scientific Technology of Ningxia Medical University, Yinchuan, 750004, Ningxia Hui Autonomous Region, People's Republic of China.,Ningxia Key Laboratory of Prevention and Control of Common Infectious Diseases of Ningxia Medical University, Yinchuan, 750004, Ningxia Hui Autonomous Region, People's Republic of China
| | - Ming-Xing Zhu
- Department of Medical genetics and Cell biology, School of Basic Medical Science of Ningxia Medical University, Yinchuan, 750004, Ningxia Hui Autonomous Region, People's Republic of China.,Center of Scientific Technology of Ningxia Medical University, Yinchuan, 750004, Ningxia Hui Autonomous Region, People's Republic of China.,Ningxia Key Laboratory of Prevention and Control of Common Infectious Diseases of Ningxia Medical University, Yinchuan, 750004, Ningxia Hui Autonomous Region, People's Republic of China
| | - Ya-Na Wang
- Department of Medical genetics and Cell biology, School of Basic Medical Science of Ningxia Medical University, Yinchuan, 750004, Ningxia Hui Autonomous Region, People's Republic of China.,Ningxia Key Laboratory of Prevention and Control of Common Infectious Diseases of Ningxia Medical University, Yinchuan, 750004, Ningxia Hui Autonomous Region, People's Republic of China
| | - Wei Zhao
- Center of Scientific Technology of Ningxia Medical University, Yinchuan, 750004, Ningxia Hui Autonomous Region, People's Republic of China. .,Ningxia Key Laboratory of Prevention and Control of Common Infectious Diseases of Ningxia Medical University, Yinchuan, 750004, Ningxia Hui Autonomous Region, People's Republic of China.
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3
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Khanna A, Sellegounder D, Kumar J, Chamoli M, Vargas M, Chinta SJ, Rane A, Nelson C, Peiris TH, Brem R, Andersen J, Lithgow G, Kapahi P. Trimethylamine modulates dauer formation, neurodegeneration, and lifespan through tyra-3/daf-11 signaling in Caenorhabditis elegans. Aging Cell 2021; 20:e13351. [PMID: 33819374 PMCID: PMC8135002 DOI: 10.1111/acel.13351] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 02/10/2021] [Accepted: 03/05/2021] [Indexed: 11/27/2022] Open
Abstract
In the nematode Caenorhabditis elegans, signals derived from bacteria in the diet, the animal's major nutrient source, can modulate both behavior and healthspan. Here we describe a dual role for trimethylamine (TMA), a human gut flora metabolite, which acts as a nutrient signal and a neurotoxin. TMA and its associated metabolites are produced by the human gut microbiome and have been suggested to serve as risk biomarkers for diabetes and cardiovascular diseases. We demonstrate that the tyramine receptor TYRA-3, a conserved G protein-coupled receptor (GPCR), is required to sense TMA and mediate its responses. TMA activates guanylyl cyclase DAF-11 signaling through TYRA-3 in amphid neurons (ASK) and ciliated neurons (BAG) to mediate food-sensing behavior. Bacterial mutants deficient in TMA production enhance dauer formation, extend lifespan, and are less preferred as a food source. Increased levels of TMA lead to neural damage in models of Parkinson's disease and shorten lifespan. Our results reveal conserved signaling pathways modulated by TMA in C. elegans that are likely to be relevant for its effects in mammalian systems.
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Affiliation(s)
- Amit Khanna
- Buck Institute for Research on Aging Novato CA USA
- Dovetail Genomics LLC Scotts Valley CA USA
| | | | | | | | | | - Shankar J. Chinta
- Buck Institute for Research on Aging Novato CA USA
- Touro University California Vallejo CA USA
| | - Anand Rane
- Buck Institute for Research on Aging Novato CA USA
| | | | | | - Rachel Brem
- Buck Institute for Research on Aging Novato CA USA
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Bacteria-derived metabolite, methylglyoxal, modulates the longevity of C. elegans through TORC2/SGK-1/DAF-16 signaling. Proc Natl Acad Sci U S A 2020; 117:17142-17150. [PMID: 32636256 DOI: 10.1073/pnas.1915719117] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Gut microbes play diverse roles in modulating host fitness, including longevity; however, the molecular mechanisms underlying their mediation of longevity remain poorly understood. We performed genome-wide screens using 3,792 Escherichia coli mutants and identified 44 E. coli mutants that modulated Caenorhabditis elegans longevity. Three of these mutants modulated C. elegans longevity via the bacterial metabolite methylglyoxal (MG). Importantly, we found that low MG-producing E. coli mutants, Δhns E. coli, extended the lifespan of C. elegans through activation of the DAF-16/FOXO family transcription factor and the mitochondrial unfolded protein response (UPRmt). Interestingly, the lifespan modulation by Δhns did not require insulin/insulin-like growth factor 1 signaling (IIS) but did require TORC2/SGK-1 signaling. Transcriptome analysis revealed that Δhns E. coli activated novel class 3 DAF-16 target genes that were distinct from those regulated by IIS. Taken together, our data suggest that bacteria-derived MG modulates host longevity through regulation of the host signaling pathways rather than through nonspecific damage on biomolecules known as advanced glycation end products. Finally, we demonstrate that MG enhances the phosphorylation of hSGK1 and accelerates cellular senescence in human dermal fibroblasts, suggesting the conserved role of MG in controlling longevity across species. Together, our studies demonstrate that bacteria-derived MG is a novel therapeutic target for aging and aging-associated pathophysiology.
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5
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Genetic Influences of the Microbiota on the Life Span of Drosophila melanogaster. Appl Environ Microbiol 2020; 86:AEM.00305-20. [PMID: 32144104 DOI: 10.1128/aem.00305-20] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 03/01/2020] [Indexed: 12/14/2022] Open
Abstract
To better understand how associated microorganisms ("microbiota") influence organismal aging, we focused on the model organism Drosophila melanogaster We conducted a metagenome-wide association (MGWA) as a screen to identify bacterial genes associated with variation in the D. melanogaster life span. The results of the MGWA predicted that bacterial cysteine and methionine metabolism genes influence fruit fly longevity. A mutant analysis, in which flies were inoculated with Escherichia coli strains bearing mutations in various methionine cycle genes, confirmed a role for some methionine cycle genes in extending or shortening fruit fly life span. Initially, we predicted these genes might influence longevity by mimicking or opposing methionine restriction, an established mechanism for life span extension in fruit flies. However, follow-up transcriptome sequencing (RNA-seq) and metabolomic experiments were generally inconsistent with this conclusion and instead implicated glucose and vitamin B6 metabolism in these influences. We then tested if bacteria could influence life span through methionine restriction using a different set of bacterial strains. Flies reared with a bacterial strain that ectopically expressed bacterial transsulfuration genes and lowered the methionine content of the fly diet also extended female D. melanogaster life span. Taken together, the microbial influences shown here overlap with established host genetic mechanisms for aging and therefore suggest overlapping roles for host and microbial metabolism genes in organismal aging.IMPORTANCE Associated microorganisms ("microbiota") are intimately connected to the behavior and physiology of their animal hosts, and defining the mechanisms of these interactions is an urgent imperative. This study focuses on how microorganisms influence the life span of a model host, the fruit fly Drosophila melanogaster First, we performed a screen that suggested a strong influence of bacterial methionine metabolism on host life span. Follow-up analyses of gene expression and metabolite abundance identified stronger roles for vitamin B6 and glucose than methionine metabolism among the tested mutants, possibly suggesting a more limited role for bacterial methionine metabolism genes in host life span effects. In a parallel set of experiments, we created a distinct bacterial strain that expressed life span-extending methionine metabolism genes and showed that this strain can extend fly life span. Therefore, this work identifies specific bacterial genes that influence host life span, including in ways that are consistent with the expectations of methionine restriction.
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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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7
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Rapamycin modulates tissue aging and lifespan independently of the gut microbiota in Drosophila. Sci Rep 2019; 9:7824. [PMID: 31127145 PMCID: PMC6534571 DOI: 10.1038/s41598-019-44106-5] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 05/09/2019] [Indexed: 12/20/2022] Open
Abstract
The FDA approved drug rapamycin can prolong lifespan in diverse species and delay the onset of age-related disease in mammals. However, a number of fundamental questions remain unanswered regarding the mechanisms by which rapamycin modulates age-related pathophysiology and lifespan. Alterations in the gut microbiota can impact host physiology, metabolism and lifespan. While recent studies have shown that rapamycin treatment alters the gut microbiota in aged animals, the causal relationships between rapamycin treatment, microbiota dynamics and aging are not known. Here, using Drosophila as a model organism, we show that rapamycin-mediated alterations in microbiota dynamics in aged flies are associated with improved markers of intestinal and muscle aging. Critically, however, we show that the beneficial effects of rapamycin treatment on tissue aging and lifespan are not dependent upon the microbiota. Indeed, germ-free flies show delayed onset of intestinal barrier dysfunction, improved proteostasis in aged muscles and a significant lifespan extension upon rapamycin treatment. In contrast, genetic inhibition of autophagy impairs the ability of rapamycin to mediate improved gut health and proteostasis during aging. Our results indicate that rapamycin-mediated modulation of the microbiota in aged animals is not causally required to slow tissue and organismal aging.
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8
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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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9
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Bacterial Methionine Metabolism Genes Influence Drosophila melanogaster Starvation Resistance. Appl Environ Microbiol 2018; 84:AEM.00662-18. [PMID: 29934334 DOI: 10.1128/aem.00662-18] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2018] [Accepted: 05/25/2018] [Indexed: 11/20/2022] Open
Abstract
Animal-associated microorganisms (microbiota) dramatically influence the nutritional and physiological traits of their hosts. To expand our understanding of such influences, we predicted bacterial genes that influence a quantitative animal trait by a comparative genomic approach, and we extended these predictions via mutant analysis. We focused on Drosophila melanogaster starvation resistance (SR). We first confirmed that D. melanogaster SR responds to the microbiota by demonstrating that bacterium-free flies have greater SR than flies bearing a standard 5-species microbial community, and we extended this analysis by revealing the species-specific influences of 38 genome-sequenced bacterial species on D. melanogaster SR. A subsequent metagenome-wide association analysis predicted bacterial genes with potential influence on D. melanogaster SR, among which were significant enrichments in bacterial genes for the metabolism of sulfur-containing amino acids and B vitamins. Dietary supplementation experiments established that the addition of methionine, but not B vitamins, to the diets significantly lowered D. melanogaster SR in a way that was additive, but not interactive, with the microbiota. A direct role for bacterial methionine metabolism genes in D. melanogaster SR was subsequently confirmed by analysis of flies that were reared individually with distinct methionine cycle Escherichia coli mutants. The correlated responses of D. melanogaster SR to bacterial methionine metabolism mutants and dietary modification are consistent with the established finding that bacteria can influence fly phenotypes through dietary modification, although we do not provide explicit evidence of this conclusion. Taken together, this work reveals that D. melanogaster SR is a microbiota-responsive trait, and specific bacterial genes underlie these influences.IMPORTANCE Extending descriptive studies of animal-associated microorganisms (microbiota) to define causal mechanistic bases for their influence on animal traits is an emerging imperative. In this study, we reveal that D. melanogaster starvation resistance (SR), a model quantitative trait in animal genetics, responds to the presence and identity of the microbiota. Using a predictive analysis, we reveal that the amino acid methionine has a key influence on D. melanogaster SR and show that bacterial methionine metabolism mutants alter normal patterns of SR in flies bearing the bacteria. Our data further suggest that these effects are additive, and we propose the untested hypothesis that, similar to bacterial effects on fruit fly triacylglyceride deposition, the bacterial influence may be through dietary modification. Together, these findings expand our understanding of the bacterial genetic basis for influence on a nutritionally relevant trait of a model animal host.
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10
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Schwarzer M, Strigini M, Leulier F. Gut Microbiota and Host Juvenile Growth. Calcif Tissue Int 2018; 102:387-405. [PMID: 29214457 DOI: 10.1007/s00223-017-0368-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 11/18/2017] [Indexed: 02/07/2023]
Abstract
Good genes, good food, good friends. That is what parents hope will sustain and nurture the harmonious growth of their children. The impact of the genetic background and nutrition on postnatal growth has been in the spot light for long, but the good friends have come to the scene only recently. Among the good friends perhaps the most crucial ones are those that we are carrying within ourselves. They comprise the trillions of microbes that collectively constitute each individual's intestinal microbiota. Indeed, recent epidemiological and field studies in humans, supported by extensive experimental data on animal models, demonstrate a clear role of the intestinal microbiota on their host's juvenile growth, especially under suboptimal nutrient conditions. Genuinely integrative approaches applicable to invertebrate and vertebrate systems combine tools from genetics, developmental biology, microbiology, nutrition, and physiology to reveal how gut microbiota affects growth both positively and negatively, in healthy and pathological conditions. It appears that certain natural or engineered gut microbiota communities can positively impact insulin/IGF-1 and steroid hormone signaling, thus contributing to the host juvenile development and maturation.
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Affiliation(s)
- Martin Schwarzer
- Institut de Génomique Fonctionnelle de Lyon (IGFL), Université de Lyon, Ecole Normale Supérieure de Lyon, CNRS UMR 5242, Université Claude Bernard Lyon 1, 69364, Lyon Cedex 07, France.
- Laboratory of Gnotobiology, Institute of Microbiology of the Czech Academy of Sciences, Nový Hrádek, Czech Republic.
| | - Maura Strigini
- INSERM, U1059, Sainbiose, Université de Lyon, Université Jean Monnet, Faculté de Médecine, Campus Santé Innovation, 42023, Saint-Étienne, France.
| | - François Leulier
- Institut de Génomique Fonctionnelle de Lyon (IGFL), Université de Lyon, Ecole Normale Supérieure de Lyon, CNRS UMR 5242, Université Claude Bernard Lyon 1, 69364, Lyon Cedex 07, France
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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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13
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Clark RI, Walker DW. Role of gut microbiota in aging-related health decline: insights from invertebrate models. Cell Mol Life Sci 2018; 75:93-101. [PMID: 29026921 PMCID: PMC5754256 DOI: 10.1007/s00018-017-2671-1] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 09/29/2017] [Indexed: 12/13/2022]
Abstract
Studies in mammals, including humans, have reported age-related changes in microbiota dynamics. A major challenge, however, is to dissect the cause and effect relationships involved. Invertebrate model organisms such as the fruit fly Drosophila and the nematode Caenorhabditis elegans have been invaluable in studies of the biological mechanisms of aging. Indeed, studies in flies and worms have resulted in the identification of a number of interventions that can slow aging and prolong life span. In this review, we discuss recent work using invertebrate models to provide insight into the interplay between microbiota dynamics, intestinal homeostasis during aging and life span determination. An emerging theme from these studies is that the microbiota contributes to cellular and physiological changes in the aging intestine and, in some cases, age-related shifts in microbiota dynamics can drive health decline in aged animals.
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Affiliation(s)
- Rebecca I Clark
- Department of Biosciences, Durham University, Durham, DH1 3LE, UK.
| | - David W Walker
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
- Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
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Stilwell MD, Cao M, Goodrich-Blair H, Weibel DB. Studying the Symbiotic Bacterium Xenorhabdus nematophila in Individual, Living Steinernema carpocapsae Nematodes Using Microfluidic Systems. mSphere 2018; 3:e00530-17. [PMID: 29299529 PMCID: PMC5750387 DOI: 10.1128/msphere.00530-17] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 11/29/2017] [Indexed: 01/01/2023] Open
Abstract
Animal-microbe symbioses are ubiquitous in nature and scientifically important in diverse areas, including ecology, medicine, and agriculture. Steinernema nematodes and Xenorhabdus bacteria compose an established, successful model system for investigating microbial pathogenesis and mutualism. The bacterium Xenorhabdus nematophila is a species-specific mutualist of insect-infecting Steinernema carpocapsae nematodes. The bacterium colonizes a specialized intestinal pocket within the infective stage of the nematode, which transports the bacteria between insects that are killed and consumed by the pair for reproduction. Current understanding of the interaction between the infective-stage nematode and its bacterial colonizers is based largely on population-level, snapshot time point studies on these organisms. This limitation arises because investigating temporal dynamics of the bacterium within the nematode is impeded by the difficulty of isolating and maintaining individual living nematodes and tracking colonizing bacterial cells over time. To overcome this challenge, we developed a microfluidic system that enables us to spatially isolate and microscopically observe individual, living Steinernema nematodes and monitor the growth and development of the associated X. nematophila bacterial communities-starting from a single cell or a few cells-over weeks. Our data demonstrate, to our knowledge, the first direct, temporal, in vivo visual analysis of a symbiosis system and the application of this system to reveal continuous dynamics of the symbiont population in the living host animal. IMPORTANCE This paper describes an experimental system for directly investigating population dynamics of a symbiotic bacterium, Xenorhabdus nematophila, in its host-the infective stage of the entomopathogenic nematode Steinernema carpocapsae. Tracking individual and groups of bacteria in individual host nematodes over days and weeks yielded insight into dynamic growth and topology changes of symbiotic bacterial populations within infective juvenile nematodes. Our approach for studying symbioses between bacteria and nematodes provides a system to investigate long-term host-microbe interactions in individual nematodes and extrapolate the lessons learned to other bacterium-animal interactions.
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Affiliation(s)
- Matthew D. Stilwell
- Department of Biochemistry, University of Wisconsin—Madison, Madison, Wisconsin, USA
| | - Mengyi Cao
- Department of Bacteriology, University of Wisconsin—Madison, Madison, Wisconsin, USA
| | - Heidi Goodrich-Blair
- Department of Bacteriology, University of Wisconsin—Madison, Madison, Wisconsin, USA
- Department of Microbiology, University of Tennessee—Knoxville, Knoxville, Tennessee, USA
| | - Douglas B. Weibel
- Department of Biochemistry, University of Wisconsin—Madison, Madison, Wisconsin, USA
- Department of Biomedical Engineering, University of Wisconsin—Madison, Madison, Wisconsin, USA
- Department of Chemistry, University of Wisconsin—Madison, Madison, Wisconsin, USA
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Gerbaba TK, Green-Harrison L, Buret AG. Modeling Host-Microbiome Interactions in Caenorhabditis elegans. J Nematol 2017; 49:348-356. [PMID: 29353922 PMCID: PMC5770281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Indexed: 06/07/2023] Open
Abstract
The microbiome influences host processes including nutritional availability, development, immunity, and behavioral responses. Caenorhabditis elegans is a powerful model to study molecular mechanisms of host-microbial interactions. Recent efforts have been made to profile the natural microbiome of C. elegans, laying a foundation for mechanistic studies of host-microbiome interactions in this genetically tractable model system. Studies using single-species microbes, multi-microbial systems, and humanized worm-microbiome interaction studies reveal metabolic and microbial-microbial interactions relevant in higher organisms. This article discusses recent developments in modeling the effects of host-microbiome interactions in C. elegans.
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Affiliation(s)
- Teklu K Gerbaba
- Department of Medicine, Queen's University, Kingston, ON, Canada
| | - Luke Green-Harrison
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Andre G Buret
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
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Shapira M. Host–microbiota interactions in Caenorhabditis elegans and their significance. Curr Opin Microbiol 2017. [DOI: 10.1016/j.mib.2017.05.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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