Asymmetric organelle positioning during epithelial polarization of C. elegans intestinal cells

AbstractThe resistance of the nematode Caenorhabditis elegans towards the highly potent toxin ricin has been studied. Incubation of C. elegans in ricin did not affect life span or progeny production. However, micro-injection of the ricin A-chain into the distal, syncitial gonad caused degeneration and sterility in test specimens, confirming that C. elegans ribosomes are sensitive. Using transmission electron microscopy, it was observed that ricin is effectively internalised into the intestinal cells. When pre-labelled with gold, the toxin reached only the lysosomes. When native toxin was used, the toxin was either routed to the lysosomes or underwent transcytosis to the pseudocoelomatic cavity and incorporation into embryos. None of the ricin reached either the trans Golgi network or the Golgi apparatus, considered essential for toxicity. The observed oral non-toxicity is therefore due to alternate sorting of the toxin, a mechanism not previously observed. The data indicate that, although ricin can opportunistically bind to, and be internalised by, cell surface receptors, these receptors are not sufficient to elicit toxicity.

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C. Elegans Fatty Acid Two-Hydroxylase Regulates Intestinal Homeostasis by Affecting Heptadecenoic Acid Production

Cellular Physiology and Biochemistry ◽

10.1159/000493226 ◽

2018 ◽

Vol 49 (3) ◽

pp. 947-960 ◽

Cited By ~ 4

Author(s):

Yuanbao Li ◽

Chunxia Wang ◽

Yikai Huang ◽

Rong Fu ◽

Hanxi Zheng ◽

...

Keyword(s):

Fatty Acid ◽

Click Chemistry ◽

Protein Transport ◽

Lipid Analysis ◽

Fatty Acyl ◽

Intestinal Cells ◽

Membrane Structures ◽

C Elegans ◽

Apical Side

Background/Aims: The hydroxylation of fatty acids at the C-2 position is the first step of fatty acid α-oxidation and generates sphingolipids containing 2-hydroxy fatty acyl moieties. Fatty acid 2-hydroxylation is catalyzed by Fatty acid 2-hydroxylase (FA2H) enzyme. However, the precise roles of FA2H and fatty acid 2-hydroxylation in whole cell homeostasis still remain unclear. Methods: Here we utilize Caenorhabditis elegans as the model and systemically investigate the physiological functions of FATH-1/C25A1.5, the highly conserved worm homolog for mammalian FA2H enzyme. Immunostaining, dye-staining and translational fusion reporters were used to visualize FATH-1 protein and a variety of subcellular structures. The “click chemistry” method was employed to label 2-OH fatty acid in vivo. Global and tissue-specific RNAi knockdown experiments were performed to inactivate FATH-1 function. Lipid analysis of the fath-1 deficient mutants was achieved by mass spectrometry. Results: C. elegans FATH-1 is expressed at most developmental stages and in most tissues. Loss of fath-1 expression results in severe growth retardation and shortened lifespan. FATH-1 function is crucially required in the intestine but not the epidermis with stereospecificity. The “click chemistry” labeling technique showed that the FATH-1 metabolites are mainly enriched in membrane structures preferable to the apical side of the intestinal cells. At the subcellular level, we found that loss of fath-1 expression inhibits lipid droplets formation, as well as selectively disrupts peroxisomes and apical endosomes. Lipid analysis of the fath-1 deficient animals revealed a significant reduction in the content of heptadecenoic acid, while other major FAs remain unaffected. Feeding of exogenous heptadecenoic acid (C17: 1), but not oleic acid (C18: 1), rescues the global and subcellular defects of fath-1 knockdown worms. Conclusion: Our study revealed that FATH-1 and its catalytic products are highly specific in the context of chirality, C-chain length, spatial distribution, as well as the types of cellular organelles they affect. Such an unexpected degree of specificity for the synthesis and functions of hydroxylated FAs helps to regulate protein transport and fat metabolism, therefore maintaining the cellular homeostasis of the intestinal cells. These findings may help our understanding of FA2H functions across species, and offer potential therapeutical targets for treating FA2H-related diseases.

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Centrosome/Cell Cycle Uncoupling and Elimination in the Endoreduplicating Intestinal Cells of C. elegans

PLoS ONE ◽

10.1371/journal.pone.0110958 ◽

2014 ◽

Vol 9 (10) ◽

pp. e110958 ◽

Cited By ~ 9

Author(s):

Yu Lu ◽

Richard Roy

Keyword(s):

Cell Cycle ◽

Intestinal Cells ◽

C Elegans

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Expression Pattern, Regulation, and Biological Role of Runt Domain Transcription Factor, run, in Caenorhabditis elegans

Molecular and Cellular Biology ◽

10.1128/mcb.22.2.547-554.2002 ◽

2002 ◽

Vol 22 (2) ◽

pp. 547-554 ◽

Cited By ~ 40

Author(s):

Seunghee Nam ◽

Yun-Hye Jin ◽

Qing-Lin Li ◽

Kwang-Youl Lee ◽

Goo-Bo Jeong ◽

...

Keyword(s):

Transcription Factor ◽

Caenorhabditis Elegans ◽

Essential Role ◽

Regulatory Elements ◽

Intestinal Cells ◽

Human Leukemia ◽

Runt Domain ◽

C Elegans ◽

Intron Region

ABSTRACT The Caenorhabditis elegans run gene encodes a Runt domain factor. Runx1, Runx2, and Runx3 are the three known mammalian homologs of run. Runx1, which plays an essential role in hematopoiesis, has been identified at the breakpoint of chromosome translocations that are responsible for human leukemia. Runx2 plays an essential role in osteogenesis, and inactivation of one allele of Runx2 is responsible for the human disease cleidocranial dysplasia. To understand the role of run in C. elegans, we used transgenic run::GFP reporter constructs and a double-stranded RNA-mediated interference method. The expression of run was detected as early as the bean stage exclusively in the nuclei of seam hypodermal cells and lasted until the L3 stage. At the larval stage, expression of run was additionally detected in intestinal cells. The regulatory elements responsible for the postembryonic hypodermal seam cells and intestinal cells were separately located within a 7.2-kb-long intron region. This is the first report demonstrating that an intron region is essential for stage-specific and cell type-specific expression of a C. elegans gene. RNA interference analysis targeting the run gene resulted in an early larva-lethal phenotype, with apparent malformation of the hypodermis and intestine. These results suggest that run is involved in the development of a functional hypodermis and gut in C. elegans. The highly conserved role of the Runt domain transcription factor in gut development during evolution from nematodes to mammals is discussed.

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BAF-1 mobility is regulated by environmental stresses

Molecular Biology of the Cell ◽

10.1091/mbc.e13-08-0477 ◽

2014 ◽

Vol 25 (7) ◽

pp. 1127-1136 ◽

Cited By ~ 14

Author(s):

Daniel Z. Bar ◽

Maya Davidovich ◽

Ayelet T. Lamm ◽

Hagit Zer ◽

Katherine L. Wilson ◽

...

Keyword(s):

Heat Shock ◽

Caloric Restriction ◽

Food Deprivation ◽

Nuclear Lamina ◽

Intestinal Cells ◽

Specific Response ◽

Missense Mutations ◽

C Elegans ◽

General Response

Barrier to autointegration factor (BAF) is an essential component of the nuclear lamina that binds lamins, LEM-domain proteins, histones, and DNA. Under normal conditions, BAF protein is highly mobile when assayed by fluorescence recovery after photobleaching and fluorescence loss in photobleaching. We report that Caenorhabditis elegans BAF-1 mobility is regulated by caloric restriction, food deprivation, and heat shock. This was not a general response of chromatin-associated proteins, as food deprivation did not affect the mobility of heterochromatin protein HPL-1 or HPL-2. Heat shock also increased the level of BAF-1 Ser-4 phosphorylation. By using missense mutations that affect BAF-1 binding to different partners we find that, overall, the ability of BAF-1 mutants to be immobilized by heat shock in intestinal cells correlated with normal or increased affinity for emerin in vitro. These results show BAF-1 localization and mobility at the nuclear lamina are regulated by stress and unexpectedly reveal BAF-1 immobilization as a specific response to caloric restriction in C. elegans intestinal cells.

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Host CDK-1 and formin mediate microvillar effacement induced by enterohemorrhagic Escherichia coli

Nature Communications ◽

10.1038/s41467-020-20355-1 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Cheng-Rung Huang ◽

Cheng-Ju Kuo ◽

Chih-Wen Huang ◽

Yu-Ting Chen ◽

Bang-Yu Liu ◽

...

Keyword(s):

Escherichia Coli ◽

Enterohemorrhagic Escherichia Coli ◽

Intestinal Cell ◽

Intestinal Cells ◽

Cyclin Dependent Kinase ◽

C Elegans ◽

Mitotic Cyclin ◽

Human Intestinal Cells

AbstractEnterohemorrhagic Escherichia coli (EHEC) induces changes to the intestinal cell cytoskeleton and formation of attaching and effacing lesions, characterized by the effacement of microvilli and then formation of actin pedestals to which the bacteria are tightly attached. Here, we use a Caenorhabditis elegans model of EHEC infection to show that microvillar effacement is mediated by a signalling pathway including mitotic cyclin-dependent kinase 1 (CDK1) and diaphanous-related formin 1 (CYK1). Similar observations are also made using EHEC-infected human intestinal cells in vitro. Our results support the use of C. elegans as a host model for studying attaching and effacing lesions in vivo, and reveal that the CDK1-formin signal axis is necessary for EHEC-induced microvillar effacement.

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Endomitosis controls tissue-specific gene expression during development

10.1101/2021.03.12.435137 ◽

2021 ◽

Author(s):

Lotte M van Rijnberk ◽

Reinier L van der Palen ◽

Erik S Schild ◽

Hendrik C Korswagen ◽

Matilde Galli

Keyword(s):

Gene Expression ◽

Cell Function ◽

Polyploid Cell ◽

Intestinal Cells ◽

Specific Gene ◽

Specific Gene Expression ◽

C Elegans ◽

Different Types ◽

Genome Ploidy ◽

Spatial Genome Organization

SummaryPolyploid cells contain more than two copies of the genome and are found in many plant and animal tissues. Different types of polyploidy exist, in which the genome is confined to either one nucleus (mononucleation) or two or more nuclei (multinucleation). Despite the widespread occurrence of polyploidy, the functional significance of different types of polyploidy are largely unknown. Here, we assess the function of multinucleation in C. elegans intestinal cells through specific inhibition of binucleation without altering genome ploidy. Through single worm RNA sequencing, we find that binucleation is important for tissuespecific gene expression, most prominently for genes that show a rapid upregulation at the transition from larval development to adulthood. Regulated genes include vitellogenins, which encode yolk proteins that facilitate nutrient transport to the germline. We find that reduced expression of vitellogenins in mononucleated intestinal cells leads to progeny with developmental delays and reduced fitness. Together, our results show that binucleation facilitates rapid upregulation of intestine-specific gene expression during development, independently of genome ploidy, underscoring the importance of spatial genome organization for polyploid cell function.

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The predicted bZIP transcription factor ZIP-1 promotes resistance to intracellular infection in Caenorhabditis elegans

10.1101/2021.06.17.448850 ◽

2021 ◽

Author(s):

Vladimir Lazetic ◽

Fengting Wu ◽

Lianne B Cohen ◽

Kirthi C Reddy ◽

Ya-Ting Chang ◽

...

Keyword(s):

Transcription Factor ◽

Caenorhabditis Elegans ◽

Rna Virus ◽

Bzip Transcription Factor ◽

Intestinal Cells ◽

Intracellular Pathogen ◽

Regulatory Pathways ◽

Intracellular Infection ◽

C Elegans ◽

Orsay Virus

Defense against intracellular infection has been extensively studied in vertebrate hosts, but less is known about invertebrate hosts. For example, almost nothing is known about the transcription factors that induce defense against intracellular infection in the model nematode Caenorhabditis elegans. Two types of intracellular pathogens that naturally infect C. elegans are the Orsay virus, which is a positive-sense RNA virus, and microsporidia, which are fungal pathogens. Surprisingly, these molecularly distinct pathogens induce a common host transcriptional response called the Intracellular Pathogen Response (IPR). Here we describe zip-1 as an IPR regulator that functions downstream of all known IPR activating and regulatory pathways. zip-1 encodes a putative bZIP transcription factor of previously unknown function, and we show how zip-1 controls induction of a subset of genes upon IPR activation. ZIP-1 protein is expressed in the nuclei of intestinal cells, and is required in the intestine to upregulate IPR gene expression. Importantly, zip-1 promotes resistance to infection by the Orsay virus and by microsporidia in intestinal cells. Altogether, our results indicate that zip-1 represents a central hub for all triggers of the IPR, and that this transcription factor plays a protective role against intracellular pathogen infection in C. elegans.

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Natural Viruses of Caenorhabditis Nematodes

Annual Review of Genetics ◽

10.1146/annurev-genet-112618-043756 ◽

2019 ◽

Vol 53 (1) ◽

pp. 313-326 ◽

Cited By ~ 4

Author(s):

Marie-Anne Félix ◽

David Wang

Keyword(s):

Model Organism ◽

Laboratory Model ◽

Intestinal Cells ◽

Caenorhabditis Briggsae ◽

C Elegans ◽

The Past ◽

Antiviral Genes ◽

Evolutionarily Conserved ◽

Positive Sense ◽

Orsay Virus

Caenorhabditis elegans has long been a laboratory model organism with no known natural pathogens. In the past ten years, however, natural viruses have been isolated from wild-caught C. elegans (Orsay virus) and its relative Caenorhabditis briggsae (Santeuil virus, Le Blanc virus, and Melnik virus). All are RNA positive-sense viruses related to Nodaviridae; they infect intestinal cells and are horizontally transmitted. The Orsay virus capsid structure has been determined and the virus can be reconstituted by transgenesis of the host. Recent use of the Orsay virus has enabled researchers to identify evolutionarily conserved proviral and antiviral genes that function in nematodes and mammals. These pathways include endocytosis through SID-3 and WASP; a uridylyltransferase that destabilizes viral RNAs by uridylation of their 3′ end; ubiquitin protein modifications and turnover; and the RNA interference pathway, which recognizes and degrades viral RNA.

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