Previously, it has been demonstrated that formate can be utilized by Saccharomyces cerevisiae as additional energy source using cells grown in a glucose-limited chemostat. Here, we investigated utilization of formaldehyde as co-substrate. Since endogenous formaldehyde dehydrogenase activities were insufficient to allow co-feeding of formaldehyde, the Hansenula polymorpha FLD1, encoding formaldehyde dehydrogenase, was introduced in S. cerevisiae. Chemostat cultivations revealed that formaldehyde was co-utilized with glucose, but the yield was lower than predicted. Moreover, formate was secreted by the cells. Upon co-expression of the H. polymorpha gene encoding formate dehydrogenase, FMD, the levels of secreted formate decreased, but the biomass yield was still lower than anticipated.
Engineering and analysis of a Saccharomyces cerevisiae strain that uses formaldehyde as an auxiliary substrate.
No sample metadata fields
View SamplesExtremely low specific growth rates (below 0.01 h-1) represent a largely unexplored area of microbial physiology. Retentostats enable controlled, energy-limited cultivation at near-zero specific growth rates while avoiding starvation. In this study, anaerobic, glucose-limited retentostats were used to analyze physiological and genome-wide transcriptional responses of Saccharomyces cerevisiae to cultivation at near-zero specific growth rates. Cultures at near-zero specific growth rates exhibited several characteristics previously associated with quiescence, including accumulation of storage polymers and an increased expression of genes involved in storage metabolism, autophagy and exit from the replicative cell cycle into G0. Analysis of transcriptome data from glucose-limited retentostat and chemostat cultures showed, as specific growth rate was decreased, quiescence-related transcriptional responses already set in at specific growth rates above 0.025 h-1. Many genes involved in mitochondrial processes were specifically upregulated at near-zero specific growth rates, possibly reflecting an increased turn-over of organelles under these conditions. Prolonged (> 2 weeks) cultivation in retentostat cultures led to induction of several genes that were previously implicated in chronological ageing. These observations stress the need for systematic dissection of physiological responses to slow growth, quiescence, ageing and starvation and indicate that controlled cultivation systems such as retentostats can contribute to this goal.
Cellular responses of Saccharomyces cerevisiae at near-zero growth rates: transcriptome analysis of anaerobic retentostat cultures.
No sample metadata fields
View SamplesCD141+DNGR-1+ cDC1 have a dual origin. Both MLP and CMP can differentiate in CD141+DNGR-1+ cDC1s.
Dendritic Cell Lineage Potential in Human Early Hematopoietic Progenitors.
Specimen part
View SamplesMesenchymal progenitor cells can be differentiated in vitro into myotubes that exhibit many characteristic features of primary mammalian skeletal muscle fibers. However, in general, they do not show the functional excitation-contraction coupling or the striated sarcomere arrangement typical of mature myofibers. Epigenetic modifications have been shown to play a key role in regulating the progressional changes in transcription necessary for muscle differentiation. In this study, we demonstrate that treatment of murine C2C12 mesenchymal progenitor cells with 10 M of the DNA methylation inhibitor 5-azacytidine (5AC) promotes myogenesis, resulting in myotubes with enhanced maturity as compared to untreated myotubes. Specifically, 5AC treatment resulted in the upregulation of muscle genes at the myoblast stage while at later stages nearly 50 % of the 5AC-treated myotubes displayed a mature, well-defined sarcomere organization as well as spontaneous contractions that coincided with action potentials and intracellular calcium transients. Both the percentage of striated myotubes and their contractile activity could be inhibited by 20 nM TTX, 10 M ryanodine and 100 M nifedipine, suggesting that action potential-induced calcium transients are responsible for these characteristics. Our data suggest that genomic demethylation induced by 5AC overcomes an epigenetic barrier that prevents untreated C2C12 myotubes from reaching full maturity.
Epigenetics: DNA demethylation promotes skeletal myotube maturation.
Cell line, Treatment
View Samplesbeta-glucan induced glycolysis in HIF-1 depedent manner. We reported that beta-glucan injection in mice led to upregulated glycolysis. HIF-1a plays a major role in this process. Overall design: Mice receives beta-glucan via ip for 4 days. Splenocytes were isolated for RNA sequencing.
mTOR- and HIF-1α-mediated aerobic glycolysis as metabolic basis for trained immunity.
No sample metadata fields
View SamplesButyrate induces Treg via HDACi activity
Metabolites produced by commensal bacteria promote peripheral regulatory T-cell generation.
Specimen part, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Inflammation-induced repression of chromatin bound by the transcription factor Foxp3 in regulatory T cells.
Specimen part
View SamplesThe transcription factor Foxp3 is indispensable for the ability of regulatory T (Treg) cells to suppress fatal inflammation. Here, we characterized the role of Foxp3 in chromatin remodeling and regulation of gene expression in actively suppressing Treg cells in an inflammatory setting. Although genome-wide Foxp3 occupancy of DNA regulatory elements was similar in resting and in vivo activated Treg cells, Foxp3-bound enhancers were poised for repression only in activated Treg cells. Following activation, Foxp3-bound sites showed reduced chromatin accessibility and selective H3K27 tri-methylation, which was associated with Ezh2 recruitment and downregulation of nearby gene expression. Thus, Foxp3 poises its targets for repression by facilitating formation of repressive chromatin in regulatory T cells upon their activation in response to inflammatory cues.
Inflammation-induced repression of chromatin bound by the transcription factor Foxp3 in regulatory T cells.
Specimen part
View SamplesExpression levels of the RNA-binding protein Quaking (QKI) are low in monocytes of early, human atherosclerotic lesions, but abundant in macrophages of advanced plaques. Specific depletion of QKI protein impaired monocyte adhesion, migration, differentiation into macrophages, and foam cell formation in vitro and in vivo. RNA-seq and microarray analysis of human monocyte and macrophage transcriptomes, including those of a unique QKI haploinsufficient patient, revealed striking changes in QKI-dependent mRNA levels and splicing of RNA transcripts. Overall design: RNA-seq analysis of primary monocytes and macrophages from a QKI haploinsufficient patient and their (control) sibling.
Quaking promotes monocyte differentiation into pro-atherogenic macrophages by controlling pre-mRNA splicing and gene expression.
No sample metadata fields
View SamplesThymic Treg cells, mature non-Treg CD4+ single positive thymocytes, peripheral (spleen) resting and activated Treg cells were sorted from Foxp3-gfp reporter (wid type, WT) mice or Foxp3 enhancer CNS3 knockout (KO, carrying the same GFP reporter) mice. Total RNA was extracted and used for RNA sequencing to assess gene expression profiles. Overall design: Two 6-8 week old littermates of male Foxp3-gfp and Foxp3?CNS3-gfp mice were used to sort Treg cells and conventional CD4+ T cells. Lymphocyte preparation and electronic sorting were performed at the same time. RNA extraction, SMART amplification, library preparation were conducted in parallel.
A mechanism for expansion of regulatory T-cell repertoire and its role in self-tolerance.
No sample metadata fields
View Samples