Project description:Gut microbiota and their metabolites influence host gene expression and physiological status through diverse mechanisms. Here we investigate how gut microbiota and their metabolites impact host's mRNA m6A epitranscriptome in various antibiotic-induced microbiota dysbiosis models. With multi-omics analysis, we find that the imbalance of gut microbiota can rewire host mRNA m6A epitranscriptomic profiles in brain, liver and intestine. We further explore the underlying mechanisms regulating host mRNA m6A methylome by depleting the microbiota with ampicillin. Metabolomic profiling shows that cholic acids are the main down-regulated metabolites with Firmicutes as the most significantly reduced genus in ampicillin-treated mice comparing to untreated mice. Fecal microbiota transplantations in germ-free mice and metabolites supplementations in cells verify that cholic acids are associated with host mRNA m6A epitranscriptomic rewiring. Collectively, this study employs an integrative multi-omics analysis to demonstrate the impact of gut microbiota dysbiosis on host mRNA m6A epitranscriptomic landscape via cholic acid metabolism.
Project description:Gut microbiota and their metabolites influence host gene expression and physiological status through diverse mechanisms. Here we investigate how gut microbiota and their metabolites impact host′s mRNA m6A epitranscriptome in various antibiotic-induced microbiota dysbiosis models. With multi-omics analysis, we find that the imbalance of gut microbiota can rewire host mRNA m6A epitranscriptomic profiles in brain, liver and intestine. We further explore the underlying mechanisms regulating host mRNA m6A methylome by depleting the microbiota with ampicillin. Metabolomic profiling shows that cholic acids are the main down-regulated metabolites with Firmicutes as the most significantly reduced genus in ampicillin-treated mice comparing to untreated mice. Fecal microbiota transplantations in germ-free mice and metabolites supplementations in cells verify that cholic acids are associated with host mRNA m6A epitranscriptomic rewiring. Collectively, this study employs an integrative multi-omics analysis to demonstrate the impact of gut microbiota dysbiosis on host mRNA m6A epitranscriptomic landscape via cholic acid metabolism.
Project description:As tissue macrophages of the central nervous system (CNS), microglia are critically involved in diseases of the CNS. However, it remains unknown what controls their maturation and activation under homeostatic conditions. Here we reveal significant contributions of the host microbiota to microglia homeostasis as germ-free (GF) mice displayed global defects in microglia with altered cell proportions and an immature phenotype leading to impaired innate immune responses. Temporal eradication of host microbiota severely changed microglia properties. Limited microbiota complexity also resulted in defective microglia. In contrast, recolonization with a complex microbiota partially restored microglia features. We determined that short-chain fatty acids (SCFA), microbiota-derived bacterial fermentation products, regulate microglia homeostasis. Accordingly, mice deficient for the SCFA receptor FFAR2 mirrored microglia defects found under GF conditions. These findings reveal that host bacteria vitally regulate microglia maturation and function, whereas microglia impairment can be restored to some extent by complex microbiota. For acute inflammatory challenges, LPS was applied intracranially and 6 hours later, animals were analyzed. Control animals were injected PBS i.c. Transcriptional profiles of FACS-sorted microglia were assessed using Affymetrix® (Santa Clara, USA) GeneChip Arrays (Mouse Gene 2.1 ST Arrays).
Project description:Difference in gut microbiome is linked with health, disease and eventually host fitness, however, the molecular mechanisms by which this variation affects the host fitness are not well characterized. Here, we modified the fish gut microbiota by using antibiotic and probiotic to address the effect of host microbiome on gene expression pattern by using transcriptome.
Project description:As tissue macrophages of the central nervous system (CNS), microglia are critically involved in diseases of the CNS. However, it remains unknown what controls their maturation and activation under homeostatic conditions. Here we reveal significant contributions of the host microbiota to microglia homeostasis as germ-free (GF) mice displayed global defects in microglia with altered cell proportions and an immature phenotype leading to impaired innate immune responses. Temporal eradication of host microbiota severely changed microglia properties. Limited microbiota complexity also resulted in defective microglia. In contrast, recolonization with a complex microbiota partially restored microglia features. We determined that short-chain fatty acids (SCFA), microbiota-derived bacterial fermentation products, regulate microglia homeostasis. Accordingly, mice deficient for the SCFA receptor FFAR2 mirrored microglia defects found under GF conditions. These findings reveal that host bacteria vitally regulate microglia maturation and function, whereas microglia impairment can be restored to some extent by complex microbiota. We used microarrays to determine the gene expression of microglia after LCMV challenge. Lymphocytic Choriomeningitis Virus (LCMV) strain WE was propagated and titrated as plaque forming units (PFU) on L929 cells as described before (Herz,J. et al. Acid sphingomyelinase is a key regulator of cytotoxic granule secretion by primary T lymphocytes. Nat. Immunol. 10, 761-768 (2009)). PFU were multiplied by the factor 10 to be converted into infectious units (IU). Mice were infected by intracerebral inoculation of 103 IU into the right hemisphere.
Project description:Vertebrates are colonized at birth by complex microbial communities (microbiota) that influence diverse aspects of host biology. We have used a functional genomics approach to identify zebrafish genes that are differentially expressed in response to the microbiota. We assessed RNA expression profiles from zebrafish larvae at 6 days post-fertilization (dpf) that were either raised continuously in the absence of any microorganism (germ-free or GF), or raised GF through 3dpf then colonized with a normal zebrafish microbiota (conventionalized or CONVD). Total RNA was purified from pooled intact zebrafish larvae (28-80 larvae/pool, 3 biological replicate pools/condition) using Trizol reagent (Invitrogen) followed by DNase I digestion (DNA-Free, Ambion) according to manufacturers' protocols. Total RNA from each replicate pool (12ug RNA/replicate) was used as template for independent cDNA synthesis and in vitro transcription reactions (BioArray HighYield RNA Transcript Labeling Kit; Enzo Life Sciences) to generate biotinylated cRNA targets. cRNA targets (20ug/replicate) were fragmented using standard methods. Hybridization and scanning were performed using standard Affymetrix protocol. Raw expression values were normalized (Invariant set method) and modeled (PM-MM model), and present/absent calls were generated using dChip software (build date Dec.11, 2005).