Similar Datasets
Project description:Vitamin B12 is an essential micronutrient that functions in two metabolic pathways: the canonical propionate breakdown pathway and the methionine/S-adenosylmethionine (Met/SAM) cycle. In Caenorhabditis elegans, low vitamin B12, or genetic perturbation of the canonical propionate breakdown pathway results in propionate accumulation and the transcriptional activation of a propionate shunt pathway. This propionate-dependent mechanism requires nhr-10 and is referred to as “B12-mechanism-I”. Here, we report that vitamin B12 represses the expression of Met/SAM cycle genes by a propionate-independent mechanism we refer to as “B12-mechanism-II”. This mechanism is activated by perturbations in the Met/SAM cycle, genetically or due to low dietary vitamin B12. B12-mechanism-II requires nhr-114 to activate Met/SAM cycle gene expression, the vitamin B12 transporter, pmp-5, and adjust influx and efflux of the cycle by activating msra-1 and repressing cbs-1, respectively. Taken together, Met/SAM cycle activity is sensed and transcriptionally adjusted to be in a tight metabolic regime.
2020-06-05 | GSE151847 | GEO
Project description:Vitamin B12 is an essential micronutrient that functions in two metabolic pathways: the canonical propionate breakdown pathway and the methionine/S-adenosylmethionine (Met/SAM) cycle. In Caenorhabditis elegans, low vitamin B12, or genetic perturbation of the canonical propionate breakdown pathway results in propionate accumulation and the transcriptional activation of a propionate shunt pathway. This propionate-dependent mechanism requires nhr-10 and is referred to as “B12-mechanism-I”. Here, we report that vitamin B12 represses the expression of Met/SAM cycle genes by a propionate-independent mechanism we refer to as “B12-mechanism-II”. This mechanism is activated by perturbations in the Met/SAM cycle, genetically or due to low dietary vitamin B12. B12-mechanism-II requires nhr-114 to activate Met/SAM cycle gene expression, the vitamin B12 transporter, pmp-5, and adjust influx and efflux of the cycle by activating msra-1 and repressing cbs-1, respectively. Taken together, Met/SAM cycle activity is sensed and transcriptionally adjusted to be in a tight metabolic regime.
2020-06-05 | GSE151846 | GEO
Project description:Vitamin B12 (B12) deficiency is a critical problem worldwide. Such deficiency in infants has long been known to increase the propensity to develop obesity and diabetes later in life through unclear mechanisms. Here, we establish a ∆nhr-114 animal as a Caenorhabditis elegans model to study how early-life B12 impacts adult health. We find that early-life B12 deficiency causes increased lipogenesis and lipid peroxidation in adult worms, which in turn induces germline defects through ferroptosis. In order to further identify genes that respond to early-life B12, we carried out an RNA sequencing (RNA-seq) assay to analyze the gene expression profiles of WT and ∆nhr-114 animals maternally supplied with 8 μM B12 or not.
2022-09-20 | GSE211747 | GEO
Project description:Dietary factors play a pivotal role in regulating metabolism in both health and disease. Lipid metabolism is particularly important for organismal health and longevity. However, the mechanisms by which dietary factors influence lipid metabolism remain poorly understood. Here, using the nematode C. elegans as a model system, we investigated the influence of distinct bacterial diets on fat metabolism. We found that dietary vitamin B12 activates the S-adenosyl methionine (SAM) and phosphatidylcholine (PC) biosynthetic pathways. This activation leads to elevated levels of PC, which in turn suppresses the expression of the gene fat-7 and modulates lipid droplet dynamics through the regulatory proteins SBP-1/SREBP1 and SEIP-1/SEIPIN, respectively. Additionally, we identified a feedback loop involving SBP-1-mediated regulation of acid sphingomyelinase ASM-3, which enhances the production of phospho-choline and further stimulates PC synthesis. Our localization studies further suggest that ASM-3 may act as a signaling mediator between the intestine and coelomocytes, coordinating their roles in vitamin B12-mediated fat regulation. Overall, our findings shed new light on the complex interplay between diet and metabolic regulation, with a particular emphasis on the central role of phosphatidylcholine. To understand the mechanism underlying the regulation of host lipid content triggered by different bacteria diets, we examined the gene expression changes elicited by the two different bacterial diets in young adult animals by RNA-seq.
2025-01-01 | GSE253268 | GEO
Project description:The two C. elegans natural microbiota isolates Pseudomonas lurida MYb11 and Pseudomonas fluorescens MYb115 protect the host against pathogens through distinct mechanisms. While P. lurida produces an antimicrobial compound and directly inhibits pathogen growth, P. fluorescens MYb115 protects the host without affecting pathogen growth. It is unknown how these two protective microbes affect host biological processes. We used a proteomics approach to elucidate the C. elegans response to MYb11 and MYb115. We found that both Pseudomonas isolates increase vitellogenin protein production in adult day 1 animals, which confirms previous findings on the effect of microbiota on C. elegans reproductive timing. Moreover, the C. elegans responses to MYb11 and MYb115 exhibit common signatures with the response to other vitamin B12-producing bacteria, emphasizing the importance of vitamin B12 in C. elegans-microbe metabolic interactions.
2024-05-24 | PXD040520 | Pride
Project description:Genome-scale metabolic network models (MNMs) can be used with a mathematical modeling tool called flux balance analysis to gain insights into metabolism at a systems level. Such models represent metabolism of an organism as a whole and do not automatically reveal how the flux overall is wired, i.e., which reactions carry flux, and which do not, and measuring flux at a large scale is challenging. Enzyme levels, as proxied by mRNA levels, can be used to predict reaction fluxes. However, integrating gene expression data with MNMs only partly constrains flux models. Here, we derive how metabolism is wired in unperturbed animals using a large-scale Worm Perturb-Seq dataset. We present a highly constrained, semi-quantitative optimal flux distribution that reflects how metabolism is wired in the animal at the adult stage. We discover several features about C. elegans metabolism that were heretofore unknown, including cyclic flux through the pentose phosphate pathway, and the primary use of amino acids and bacterial RNA as an energy source, all of which we validated by isotope tracing. Our strategy for inferring metabolic wiring based solely on gene expression should be applicable to a variety of systems, including human cells. This dataset includes the RNA-seq profiles collected during the proof-of-concept studies on the metrics used for predicting flux wiring from Worm Perturb-Seq dataset. It includes three sets of data: the profiles of animals fed live versus paraformaldehyde-killed (PFA killed) bacteria; the profiles of gene knockdowns in propionate degradation metabolism under a gradient of vitamin B12 supplementation; and the profiles of gene knockdowns in Met/SAM cycle under vitamin B12 and choline supplementations.
2024-11-20 | GSE255866 | GEO
Project description:Vitamin B12 depletion or propionate supplementation can reverse the transcriptomic aberration in the C. elegans model of PD with neuronal overexpression of alpha-synuclein A53T
2023-04-28 | GSE230786 | GEO
Project description:Recent functional genomics and genome-scale modeling approaches indicated that B12 production in Lactobacillus reuteri could be improved by medium optimization. Here we show that a series of systematic single amino acid omissions could significantly modulate the production of B12 from nearly undetectable levels (by isoleucine omission) to 20-fold higher than previously reported through omission of cysteine. We analyzed by cDNA microarray experiments the transcriptional response of L. reuteri to the medium lacking cysteine. These results supported the observed high B12 production and provided new avenues for future improvement of production of vitamin B12. Keywords: cell type comparison loop design
2010-05-17 | E-GEOD-13391 | biostudies-arrayexpress
Project description:Recent functional genomics and genome-scale modeling approaches indicated that B12 production in Lactobacillus reuteri could be improved by medium optimization. Here we show that a series of systematic single amino acid omissions could significantly modulate the production of B12 from nearly undetectable levels (by isoleucine omission) to 20-fold higher than previously reported through omission of cysteine. We analyzed by cDNA microarray experiments the transcriptional response of L. reuteri to the medium lacking cysteine. These results supported the observed high B12 production and provided new avenues for future improvement of production of vitamin B12. Keywords: cell type comparison
2008-10-31 | GSE13391 | GEO
Project description:Vitamin B12 (B12) is an important cofactor in mycobacterial metabolism, and some pathogenic mycobacteria need to obtain it from the host. In this study, we investigated the transport of vitamin B12 in Mycobacterium marinum. We identified a transcriptor regulator that could be potentially involved in the uptake process. RNA sequencing analysis were performed in order to elucidate the regulon of this new transcriptor.
2023-08-14 | GSE240448 | GEO