Project description:To begin to explore mechanisms by which microbiota signals regulate HSC lineage bias, gene expression profiling was performed on sorted LSK-SLAM cells from aged SPF and aged GF mice.
Project description:Advanced age is associated with chronic low-grade inflammation, which is usually referred to as inflammaging. Elderly are also known to have an altered gut microbiota composition. However, whether inflammaging is a cause or consequence of an altered gut microbiota composition is not clear. In this study gut microbiota from young or old conventional mice was transferred to young germ-free mice. Four weeks after gut microbiota transfer immune cell populations in spleen, Peyer’s patches, and mesenteric lymph nodes from conventionalized germ-free mice were analyzed by flow cytometry. In addition, whole-genome gene expression in the ileum was analyzed by microarray. Gut microbiota composition of donor and recipient mice was analyzed with 16S rDNA sequencing. Here we show by transferring aged microbiota to young germ-free mice that certain bacterial species within the aged microbiota promote inflammaging. This effect was associated with lower levels of Akkermansia and higher levels of TM7 bacteria and Proteobacteria in the aged microbiota after transfer. The aged microbiota promoted inflammation in the small intestine in the germ-free mice and enhanced leakage of inflammatory bacterial components into the circulation was observed. Moreover, the aged microbiota promoted increased T cell activation in the systemic compartment. In conclusion, these data indicate that the gut microbiota from old mice contributes to inflammaging after transfer to young germ-free mice.
Project description:To understand the effect of microbes on microRNAs in aorta, in this study, we examined expression of microRNA in the aorta of male (10 weeks old) germ-free mice and pathogen-free mice (control).
Project description:Liver clock regulates transcription of hepatic genes in response to feeding. To explore the possibility that the microbiome influences this process, we measured the liver transcriptome in normal mice (Specific Pathogen Free or SPF mice) and compared it to the transcriptome in mice lacking microbiota (Germ Free or GF mice) at different time points over 24h. We used microarrays to detail the global programme of gene expression in liver of GF and SPF 10-12 weeks-old male C57Bl/6 male mice. There are 40 liver samples, each from an individual mouse. The samples are from germ free mice (GF) and specific pathogen free mice (SPF). Mice of both types were sacrificed at four time points: Zeitgeber Time 0, 6, 12, and 18. There are five replicates per condition.
Project description:Liver clock regulates transcription of hepatic genes in response to feeding. To explore the possibility that the microbiome influences this process, we measured the liver transcriptome in normal mice (Specific Pathogen Free or SPF mice) and compared it to the transcriptome in mice lacking microbiota (Germ Free or GF mice) at different time points over 24h. We used microarrays to detail the global programme of gene expression in liver of GF and SPF 10-12 weeks-old male C57Bl/6 male mice.
Project description:The small intestinal epithelial barrier inputs signals from the gut microbiota in order to balance physiological inflammation and tolerance, and to promote homeostasis. Understanding the dynamic relationship between microbes and intestinal epithelial cells has been a challenge given the cellular heterogeneity associated with the epithelium and the inherent difficulty of isolating and identifying individual cell types. Here, we used single-cell RNA sequencing of small intestinal epithelial cells from germ-free and specific pathogen-free mice to study microbe-epithelium crosstalk at the single cell resolution.