Project description:Reprogramming in vivo using OCT4, SOX2, KLF4 and MYC (OSKM) triggers cell dedifferentiation, which is considered of relevance for tissue repair and regeneration. However, little is known about the metabolic requirements of this process. We found that antibiotic depletion of the gut microbiota abolished in vivo reprogramming. Analysis of bacterial metagenomes from stool samples of wild type (WT) and OSKM mice treated with doxycycline led us to identify vitamin B12 as a key factor for in vivo reprogramming, which is partly supplied by the microbiome. We report that B12 demand increases during reprogramming due to enhanced expression of enzymes in the methionine cycle, and supplementing B12 levels both in vitro and in vivo enhances the efficiency of OSKM reprogramming.
Project description:The transcriptome in response to vitamin B12 was interrogated in three M. tuberculosis Complex species: M. tuberculosis H37Rv, M. tuberculosis GC1237, and M. bovis AF2122/97. Examination of the core B12 transcriptome resulted in a robust differential regulation of 7 genes in the three species analysed
Project description:We used microarrays to detail the global gene expression profiles of OSKM and N2OSKM-infected MEFs over a time course (3, 7, 11 dpi).
Project description:RNA-Seq results accompanying submission of a manuscript: "Cholesterol-dependent transcriptome remodeling reveals new insight into the contribution of cholesterol to Mycobacterium tuberculosis pathogenesis" describing the role of cholesterol and vitamin B12 in shaping the transcriptome of the Mycobacterium tuberculosis H37Rv and M. tuberculosis ∆prpR - propionate regulator (PrpR) mutant. Next generation sequencing results are provided in three independent biological replicates for each strain growing in three different media - minimal medium with glycerol or cholesterol as the sole carbon source and standard 7H9/10% OADC medium. The influence of vitamin B12 on M. tuberculosis transcriptome was analysed on 7H9/10% OADC medium supplemented with B12. The study allowed us to re-establish the list of genes potentially involved in cholesterol metabolism. We further proposed a novel regulatory function of vitamin B12 and PrpR, a propionate regulator, in coordinated cholesterol breakdown metabolite dissipation and virulent phenotype induction. Finally, we demonstrated that a key role of cholesterol in Mtb metabolism is not only providing carbon and energy but also inducing a transcriptome remodeling program that helps in developing tolerance to the unfavorable host cell environment.
Project description:Coastal Antarctic marine ecosystems play an important role in carbon cycling due to their highly productive seasonal phytoplankton blooms. Southern Ocean microbes are primarily limited by light and iron (Fe) and can be co-limited by cobalamin (vitamin B12 ). Micronutrient limitation is a key driver of ecosystem dynamics and influences the composition of blooms, which are often dominated by either diatoms or the haptophyte Phaeocystis antarctica, each with varied impacts on carbon cycling. However, the vitamin requirements and ecophysiology of the keystone species P. antarctica remains poorly characterized. Using cultures, physiological analysis, and comparative ’omics we examined the response of P. antarctica to a matrix of Fe-B12 conditions. We show that P. antarctica is not auxotrophic for B12 , as previously suggested, and report new mechanistic insights of its B12 response in cultures of predominantly solitary and colonial cells. Proteomics coupled with proteogenomics detected a B12 -independent methionine synthase fusion protein (MetE-fusion) that is expressed under vitamin limitation and is interreplaced with the B12 -dependent isoform (MetH) in replete conditions. Database searches returned homologs of the MetE-fusion protein in multiple Phaeocystis species and in a wide range of marine microbes, including other photosynthetic eukaryotes with polymorphic life cycles and also bacterioplankton. Furthermore, MetE-fusion homologs were found to be expressed in metaproteomic and metatranscriptomic field samples in polar and more geographically widespread regions. As climate change impacts micronutrient availability in the coastal Southern Ocean, our finding that P. antarctica has a flexible B12 metabolism has implications for its relative fitness compared to B12 -auxotrophic diatoms.
Project description:We investigated the effects of one carbon metabolites supplementation on early embryonic development. To this end, the Bovine Embryonic Tracheal Fibroblast cell lines (EBTr; NBL-4; ATCC CCL-44) were cultured under different levels of glucose and OCM (folic acid, choline chloride, vitamin B12, and L-methionine).