Profiling gene expression in M. tuberculosis under different in vitro conditions.
Ontology highlight
ABSTRACT: This RNA-Seq study of gene expression in M. tuberculosis was done as part of the FLUTE project (NIH grant U19-AI107774, Eric Rubin, program director). There are 3 replicates each for Mtb H37Rv grown under the following conditions: 0.1% butyrate, 0.4% glucose, butyrate+glucose, low iron, acidic conditions, and several RIF-resistant mutants of Beijing strain HN878 with different mutations in RpoB.
Project description:An intergenic region found to be enriched from a genomic library under butyrate stress was overexpressed and challenged with butyrate (0.6%). The overexpression strain was compared to the plasmid control to determine the transcriptional changes due to overexpression and butyrate stress. RNA samples were taken from both the overexpression strain (pRDNA7) and the plasmid control strain (pSOS95del) at 0, 15, 40, 120, 240, and 360 min post a 0.6% butyrate (pH 6.7) stress. Two slides per timepoint were hybridized on a dye swap configuration.
Project description:Ribosome immunoprecipitates of cardiomyocytes isolated from Rpl3l-/- and Rpl3l+/+ mouse hearts were analysed using mass spectrometry.
Project description:Acetate, propionate and butyrate are the main short-chain fatty acids (SCFAs) that arise from the fermentation of fibers by the colonic microbiota. While many studies focus on the regulatory role of SCFAs, their quantitative role as a catabolic or anabolic substrate for the host has received relatively little attention. To investigate this aspect, we infused conscious mice with physiological quantities of stable isotopes [1-13C]acetate, [2-13C]propionate or [2,4-13C2]butyrate directly into the cecum, which is the natural production site in mice, and analyzed their interconversion by the microbiota as well as their metabolism by the host. Cecal interconversion - pointing to microbial cross-feeding - was high between acetate and butyrate, low between butyrate and propionate and almost absent between acetate and propionate. As much as 62% of infused propionate was used in whole-body glucose production, in line with its role as gluconeogenic substrate. Conversely, glucose synthesis from propionate accounted for 69% of total glucose production. The synthesis of palmitate and cholesterol in the liver was high from cecal acetate (2.8% and 0.7%, respectively) and butyrate (2.7% and 0.9%, respectively) as substrates, but low or absent from propionate (0.6% and 0.0%, respectively). Label incorporation due to chain elongation of stearate was approximately 8-fold higher than de novo synthesis of stearate. Microarray data suggested that SCFAs exert only a mild regulatory effect on the expression of genes involved in hepatic metabolic pathways during the 6h infusion period. Altogether, gut-derived acetate, propionate and butyrate play important roles as substrates for glucose, cholesterol and lipid metabolism.
Project description:Acetate, propionate and butyrate are the main short-chain fatty acids (SCFAs) that arise from the fermentation of fibers by the colonic microbiota. While many studies focus on the regulatory role of SCFAs, their quantitative role as a catabolic or anabolic substrate for the host has received relatively little attention. To investigate this aspect, we infused conscious mice with physiological quantities of stable isotopes [1-13C]acetate, [2-13C]propionate or [2,4-13C2]butyrate directly into the cecum, which is the natural production site in mice, and analyzed their interconversion by the microbiota as well as their metabolism by the host. Cecal interconversion - pointing to microbial cross-feeding - was high between acetate and butyrate, low between butyrate and propionate and almost absent between acetate and propionate. As much as 62% of infused propionate was used in whole-body glucose production, in line with its role as gluconeogenic substrate. Conversely, glucose synthesis from propionate accounted for 69% of total glucose production. The synthesis of palmitate and cholesterol in the liver was high from cecal acetate (2.8% and 0.7%, respectively) and butyrate (2.7% and 0.9%, respectively) as substrates, but low or absent from propionate (0.6% and 0.0%, respectively). Label incorporation due to chain elongation of stearate was approximately 8-fold higher than de novo synthesis of stearate. Microarray data suggested that SCFAs exert only a mild regulatory effect on the expression of genes involved in hepatic metabolic pathways during the 6h infusion period. Altogether, gut-derived acetate, propionate and butyrate play important roles as substrates for glucose, cholesterol and lipid metabolism. Mice were infused in cecum with stably-labelled isotopes of the three main short chain fatty acids or control solution. After 6 hrs, livers were removed and pooled RNA samples were subjected to gene expression profiling.
Project description:The present study was aimed at analyzing (i) the biological cost of RNA polymerase (rpoB) mutations conferring rifampin resistance on H.pylori, (ii) the relationship between the cost of rpoB mutations and the chromosomal mutaion, (iii) the relationship between the cost of rpoB mutations and the transcription profile of sensitive and resistantrif strains of H.pylori (iv) and rpoB mutations in view of the possible fitness burden associated with resistance to another antibiotics.
Project description:This RNA-Seq study of gene expression in M. tuberculosis was done as part of the FLUTE project (NIH grant U19-AI107774, Eric Rubin, program director).
Project description:This RNA-Seq study of gene expression in M. tuberculosis was done as part of the FLUTE project (NIH grant U19-AI107774, Eric Rubin, program director).
Project description:CDC1551 induced more vigorous immune response in murine bone marrow derived macrophage (BMM). In contrast, in HN878-infected cells, host transcriptional response was delayed but lasted longer. HN878 induced more genes involved in host lipid metabolism than CDC1551 did.
Project description:Beta cell dysfunction, caused by metabolic and inflammatory stress, contributes to the development of type 2 diabetes. Butyrate, produced by the gut microbiota, has shown beneficial effects on glucose metabolism and may directly affect beta cell function, but the mechanisms are poorly described. The aim of this study was to investigate the effect of butyrate on IL-1β-induced β cell dysfunction. We showed that long-term exposure of mouse islets to non-cytotoxic concentrations of IL-1β impaired insulin secretion and content and reduced proliferation. This dysfunction was prevented when the islets were exposed to butyrate and butyrate alone also boosted insulin secretion. In contrast, butyrate further downregulated the proliferation. To get a better indication of mechanisms of actions we investigated the global mRNA expression profiles using RNA sequencing. Our results indicated that the protective effects of butyrate are associated with upregulation of secretion/transport-related genes and downregulation of inflammatory genes induced by IL-1β. In addition, several cell cycle related genes were strongly inhibited by butyrate. In conclusion, butyrate plays an essential role in supporting beta cell function under inflammatory conditions, suggesting a potential for therapeutic use in treatment and prevention of T2D.
Project description:CDC1551 induced more vigorous immune response in murine bone marrow derived macrophage (BMM). In contrast, in HN878-infected cells, host transcriptional response was delayed but lasted longer. HN878 induced more genes involved in host lipid metabolism than CDC1551 did. Murine bone marrow derived macrophages were infected with M. tuberculosis CDC1551 or HN878 up to 24 h. Total RNA was processed for microarray and global gene expression was read.