Turek, Michal et al. (2021) International Worm Meeting "Nutritional status and fecundity are synchronised by muscular exopheresis"

Nowak, Natalia, Piechota, Malgorzata, Sliwinska, Malgorzata, Banasiak, Katarzyna, Kowalski, Konrad, Turek, Michal, Pokrzywa, Wojciech, Niklewicz, Marta, Chacinska, Agnieszka, Macias, Matylda, Shanmugam, Nilesh

[International Worm Meeting, 2021]

Organismal functionality and reproduction depend on metabolic rewiring and balanced energy resources. However, the crosstalk between organismal homeostasis and fecundity, and the associated paracrine signaling mechanisms are still poorly understood. Using the Caenorhabditis elegans we discovered that large extracellular vesicles termed exophers, attributed in neurons and cardiomyocytes to the removal of damaged subcellular components, are released by body wall muscles to support embryonic growth. We found that exopher formation (exopheresis) is a non-cell autonomous process regulated by developing embryos in the uterus. Our data suggest that exophers serve as transporters for muscle-generated yolk proteins used for nourishing and improving the growth rate of the next generation. We propose that the primary role of muscular exopheresis is to stimulate the reproductive capacity, thereby influencing the adaptation of worm populations to the current environmental conditions.

Cram EJ (2021) EMBO Rep "Exophers to feed them all."

Cram EJ

[EMBO Rep, 2021]

Cells release extracellular vesicles to remove damaged components and communicate with other cells via packets of proteins, lipids, and RNAs. Neuronal cells in the nematode C.elegans release particularly large extracellular vesicles, known as exophers, to rid themselves of damaged organelles and protein aggregates. Turek etal now demonstrate a new role for these vesicles: Embryos in the uterus stimulate body wall muscle cells to release exophers laden with yolk, which are taken up by oocytes to nourish the next set of embryos (Turek etal, 2021).

Braeckman BP et al. (1999) Trends Microbiol "Stress-inducible mechanisms of life-span extension in yeast, eubacteria and metazoans."

Braeckman BP, Vanfleteren JR

[Trends Microbiol, 1999]

As outlined by Michal Jazwinski in his recent review, multiple pathways appear to play a role in determining yeast longevity. One mechanism involves the illegitimate replication of extrachromosomal rDNA circles to toxic levels. A similar sequence of events involving excision, circularization and unfettered replication of mitochondrial (mt) DNA (called senDNA) induces senescence in the fungus Podospora anserina.

andrione, mara et al. (2019) International Worm Meeting "RIS dynamics during sleep and wakefulness in freely-moving worms."

andrione, mara, Zimmer, Manuel, nichols, annika

[International Worm Meeting, 2019]

In both vertebrates and invertebrates, sleep-active neurons depolarize at sleep onset and, with their interplay with wake-promoting centers, guarantee fast and reliable switches between global brain states. However, how sleep homeostatic or circadian pressure influences their activity remains elusive1. While quiescent states in C. elegans are typically accompanied by downregulation of most neuronal activity2,3, the GABAergic and peptidergic interneuron RIS is both sleep-active and sleep-inducing4,5. Several evidences also point to a function of RIS more generally in sleep promotion2,3,6. These aspects represent discrete non-mutual exclusive hypotheses about RIS function, as either a final effector of the brain-state switch or a mediator of sleep pressure. The upregulation of RIS was first observed during lethargus sleep, but recent evidences show similar modulations occurring in different types of sleep, both in adulthood and during the larval stages3,7. Here, we first report about a previously uncharacterized type of spontaneous sleep in adult C. elegans. Then, through Ca2+ imaging of RIS in freely-moving animals, we draw a comparison between RIS dynamics seen during immobility periods in L4 lethargus and in adulthood. By using an arousing stimulation paradigm - O2 concentration shifts in worms with an npr-1 mutant background - we compare basal RIS activity patterns with those following sleep-deprivation. With this approach, we aim to disentangle to what extent sleep pressure and sleep induction are represented in RIS activity. 1: H Bringmann (2018) Genetics 2: ALA Nichols et al (2017) Science 3: S Skora et al (2018) Cell Reports 4: M Turek et al (2013) Current Biology 5: M Turek et al (2016) Elife 6: J Spies & H Bringmann (2018) Scientific Reports 7: Y Wu et al (2018) Current Biology

Petr Liby et al. (2006) European Worm Meeting "Inhibition of bir-1, the Homologue of Human Survivin, Induces Changes of Expression of Developmentally Active Collagen Genes in L1 Larval Stage"

Marta Kostrouchova, Eva Brozova, Marketa Kostrouchova, Michal Pohludka, Jaroslav Vohanka, Petr Liby, Zdenek Kostrouch

[European Worm Meeting, 2006]

Petr Liby1, Marketa Kostrouchova1, Michal Pohludka1, Jaroslav Vohanka2, Eva Brozova2, Marta Kostrouchova2 and Zdenek Kostrouch1. BIR-1 is a member of the Inhibitors of Apoptosis protein family that is involved in the regulation of microtubule organization, condensation of chromosomes and cell division in C. elegans as well as in vertebrates. In C. elegans, bir-1 is organized in an operon together with SKIP, a transcription and splicing cofactor. bir-1 inhibition induces developmental defects including dpy and egl phenotypes. Here we studied the effect of bir-1 inhibition by RNAi in L1 larval stage using whole genome microarrays (Affymetrix). Microarrays detected changes in expression of several developmentally active collagen genes in bir-1 inhibited larvae. We further characterized the effect of bir-1 inhibition on selected collagen gene expression and induction of dpy phenotype. Acknowledgement: We thank Drs. A. Fire for GFP construct, vectors and host used in RNAi and M.W. Krause for support and advice. We thank the NIDDK Microarrays facility for performing the microarrays analysis. The work was supported by the grant 303/03/0333 from the Czech Science Foundation, by the grant NC-7554 from the Ministry of Health of the Czech Republic and by the grant 0021620806 from the Ministry of Education, Youth and Sports of the Czech Republic.

Katerina Simeckova et al. (2006) European Worm Meeting "NHR-60, a Caenorhabditis elegans Supplementary Nuclear Receptor residing at the Nuclear Periphery, Regulates Embryonic Development in Connection with Acyl-Coenzyme a Binding Protein"

Zdenek Kostrouch, Eva Brozova, Marta Kostrouchova, Jaroslav Vohanka, Katerina Simeckova, Michal Pohludka

[European Worm Meeting, 2006]

Katerina Simeckova1, Eva Brozova1, Jaroslav Vohanka1, Michal Pohludka2, Zdenek Kostrouch2, Marta Kostrouchova1 . NHR-60 is a Caenorhabditis elegans supplementary nuclear receptor that belongs to a subset of 18 of the 284 nuclear hormone receptors characterized by the P-box sequence CNGCKT. We show that NHR-60 is expressed ubiquitously and is predominantly localized at the nuclear periphery. The expression of NHR-60 is accented in seam cells, gland cells and in the germline. In seam cells, the expression of NHR-60 is dependent on CHR3 (NHR-23). Our research also focused on the possible interaction of Acyl-CoA-binding protein, which is known to interact with several nuclear hormone receptors, and NHR-60. The interaction in vivo between these two proteins was confirmed by co-immunoprecipitation and co-localization using confocal microscopy. acbp-1 inhibition by RNAi induced developmental defects similar to nhr-60 RNAi. These results indicate that regulation of development by nuclear hormone receptor NHR-60 is functionally linked to Acyl-CoA-binding protein and may constitute a connection with fat metabolism. Acknowledgement: We thank Drs. A. Fire for vectors and host used in RNAi and M.W. Krause for support and advice. The work was supported by grants 303/03/1115 and 301/05/0859 from the Czech Science Foundation and by the grant 0021620806 from the Ministry of Education, Youth and Sports of the Czech Republic.

Michal Pohludka et al. (2006) European Worm Meeting "Analysis of CHR-3 (nhr-23) Loss of Function in L1 Larval Stage Using Whole Genome Microarrays and Comparative Two Dimensional Protein Chromatography"

Zdenek Kostrouch, Marta Kostrouchova, Michal Pohludka, Jaroslav Vohanka

[European Worm Meeting, 2006]

Analysis of CHR-3 (nhr-23) Loss of Function in L1 Larval Stage Using Whole Genome Microarrays and Comparative Two Dimensional Protein Chromatography. Michal Pohludka1, Jaroslav Vohanka2, Marta Kostrouchova2 and Zdenek Kostrouch1. CHR3 (nhr-23, NR1F4) is an evolutionarily conserved nuclear receptor involved in the regulation of molting and body morphology in larval development. We studied the role of CHR-3 (nhr-23) by RNAi in L1 stage and analysed the phenotype on mRNA and protein levels using whole genome microarrays (Affymetrix) and a comparative two dimensional protein chromatography by ProteomeLab PF 2D Protein Fractionation System. Protein profiling was achieved by Isoelectric chromatofocusing used as the first dimension separation and reversed phase chromatography separating proteins by hydrophobicity as the second dimension. The differentially expressed proteins were detected by ProteoVue and DeltaVue Software. Microarrays data subjected to computer analysis using GeneSpring program detected clusters of similarly regulated genes. Two dimensional chromatography revealed multiple fractions containing differentially expressed proteins in CHR3 (nhr-23) inhibited fractions suitable for analysis by mass spectroscopy. Genome and proteome wide analysis may help to further characterize phenotypes of gene inhibition by RNAi. Acknowledgement: We thank Drs. A. Fire for GFP construct, vectors and host used in RNAi and M.W. Krause for support and advice. We thank the NIDDK Microarrays Facility for performing the microarrays analysis. The work was supported by the grants 301/05/0859 and 303/03/0333 from the Czech Science Foundation, and by the grant 0021620806 from the Ministry of Education of the Czech Republic.

Susoy, Vladislav et al. (2019) MicroPubl Biol

Rahi, Sahand J, Susoy, Vladislav, Joyce, William J

[MicroPubl Biol, 2019]

In C. elegans hermaphrodites, sto-3 promoter has been previously shown to drive gene expression in RIBL/R neurons and in three unidentified non-neuronal cells in the tail (Turek et al., 2016). (A) We have found that in C. elegans males, in addition to RIBL/R, two pairs of bilaterally-symmetrical tail neurons show strong Psto3::wrmScarlet expression (wrmScarlet is a codon-optimized version of mScarlet (El Mouridi et al., 2017)). These neurons send their processes to rays 4 and 8 of the male tail. In the figure, right lateral aspect is shown; arrows indicate rays containing processes expressing Psto3::wrmScarlet. (B) All rays in the male tail are innervated by A and B type neurons (Sulston et al., 1980). To identify which neuron type expresses the sto-3 reporter, we have crossed Psto3::wrmScarlet transgenic males with a Ppkd-2::GFP reporter strain MT11318, which expresses GFP in the B-type neurons of rays 1-5, 7-9 and not in the A-type neurons (Barr and Sternberg, 1999). In the F1 cross-progeny males, which also carried the ceh-30(n3714) mutation in the background, Psto-3::wrmScarlet expression is colocalized with Ppkd-2::GFP for both pairs of ray neurons expressing Psto-3::wrmScarlet. This indicates that sto-3 is expressed in the R4BL/R and R8BL/R ray neurons. Left lateral aspect; arrows point at the cell bodies of Psto3::wrmScarlet-expressing neurons.

Rohacek, Alex et al. (2019) International Worm Meeting "The conserved transcription factor mef-2 regulates sickness induced sleep."

Rohacek, Alex, Raizen, David

[International Worm Meeting, 2019]

Sleep disruption is a common feature of neurodevelopmental disorders. As such, gaining a detailed mechanistic understanding of sleep circuit development will help elucidate causative factors in neurodevelopmental sleep disorders. Previous work has illuminated aspects of the development of sleep controlling neurons ALA (van Buskirk and Sternberg '10) and RIS (Turek et al '13), but much is yet to be discovered regarding the larger sleep circuit and how sleep signals are interpreted by the body. C. elegans experience stress or sickness induced sleep (SIS) in response to infection, radiation treatment, heat shock, or osmotic stress. During SIS, the ALA neuron is activated by Epidermal Growth Factor (EGF) to release the sleep-inducing neuropeptides FLP-13, FLP-24, and NLP-8. Differential effects of these peptides on feeding and movement quiescence suggest that parallel pathways regulate different aspects of quiescence during sleep (Nath et al, '16). Myocyte Enhancer Factor 2 (MEF-2) is a transcription factor that regulates the expression of genes involved in development of both muscles and neurons. In C. elegans, mef-2 regulates muscle to neuron signaling at the neuromuscular junction (Simon et al, '08). We find that animals lacking mef-2 function are defective in movement but not feeding quiescence during SIS. Mef-2 mutants are resistant to EGF but not FLP-13 overexpression induced movement quiescence, suggesting that mef-2 functions in the development of the ALA neuron. Surprisingly, we find that muscle (myo-3 promoter) but not neural (rab-3 promoter) mef-2 expression rescued the SIS defects in these animals. Our working hypothesis is that mef-2 regulates the development of neuronal sleep circuitry by acting in muscle cells.

Rohacek, Alex et al. (2021) International Worm Meeting "The conserved transcription factor mef-2 regulates sickness induced sleep"

Raizen, David, Rohacek, Alex

[International Worm Meeting, 2021]

Sleep disruption is a common feature of neurodevelopmental disorders. As such, gaining a detailed mechanistic understanding of sleep circuit development will help elucidate causative factors in neurodevelopmental sleep disorders. Previous work has illuminated aspects of the development of sleep controlling neurons ALA (van Buskirk and Sternberg '10) and RIS (Turek et al '13), but much is yet to be discovered regarding the larger sleep circuit and how sleep signals are interpreted by the body. C. elegans experience stress or sickness induced sleep (SIS) in response to infection, radiation treatment, heat shock, or osmotic stress. During SIS, the ALA neuron is activated by Epidermal Growth Factor (EGF) to release the sleep-inducing neuropeptides FLP-13, FLP-24, and NLP-8. Differential effects of these peptides on feeding and movement quiescence suggest that parallel pathways regulate different aspects of quiescence during sleep (Nath et al, '16). Myocyte Enhancer Factor 2 (MEF-2) is a transcription factor that regulates the expression of genes involved in development of both muscles and neurons. In C. elegans, mef-2 regulates muscle to neuron signaling at the neuromuscular junction (Simon et al, '08). We find that animals lacking mef-2 function are defective in movement but not feeding quiescence during SIS. Mef-2 mutants are resistant to EGF but not FLP-13 overexpression induced movement quiescence, suggesting that mef-2 functions in the development of the ALA neuron. Surprisingly, we find that muscle (myo-3 promoter) but not neural (rab-3 promoter) mef-2 expression rescued the SIS defects in these animals. Our working hypothesis is that mef-2 regulates the development of neuronal sleep circuitry by acting in muscle cells.