Project description:Gut microbiome research is rapidly moving towards the functional characterization of the microbiota by means of shotgun meta-omics. Here, we selected a cohort of healthy subjects from an indigenous and monitored Sardinian population to analyze their gut microbiota using both shotgun metagenomics and shotgun metaproteomics. We found a considerable divergence between genetic potential and functional activity of the human healthy gut microbiota, in spite of a quite comparable taxonomic structure revealed by the two approaches. Investigation of inter-individual variability of taxonomic features revealed Bacteroides and Akkermansia as remarkably conserved and variable in abundance within the population, respectively. Firmicutes-driven butyrogenesis (mainly due to Faecalibacterium spp.) was shown to be the functional activity with the higher expression rate and the lower inter-individual variability in the study cohort, highlighting the key importance of the biosynthesis of this microbial by-product for the gut homeostasis. The taxon-specific contribution to functional activities and metabolic tasks was also examined, giving insights into the peculiar role of several gut microbiota members in carbohydrate metabolism (including polysaccharide degradation, glycan transport, glycolysis and short-chain fatty acid production). In conclusion, our results provide useful indications regarding the main functions actively exerted by the gut microbiota members of a healthy human cohort, and support metaproteomics as a valuable approach to investigate the functional role of the gut microbiota in health and disease.
Project description:Hibernation is an energy-saving strategy adopted by a wide range of mammals to survive highly seasonal or unpredictable environments. Arctic ground squirrels living in Alaska provide an extreme example, with 6-9 months long hibernation seasons when body temperature alternates between levels near 0 C during torpor and 37 C during arousal episodes. Heat production during hibernation is provided, in part, by non-shivering thermogenesis that occurs in large deposits of brown adipose tissue (BAT). BAT is active at tissue temperatures from 0 to 37 C during rewarming and continuously at near 0 C during torpor in subfreezing conditions. Despite its crucial role in hibernation, the global gene expression patterns in BAT during hibernation compared to the non-hibernation season remain largely unknown. We report a large-scale study of differential gene expression in BAT between winter hibernating and summer active arctic ground squirrels using mouse microarrays. Selected differentially expressed genes identified on the arrays were validated by quantitative real-time PCR using ground squirrel specific primers. Our results show that the mRNA levels of the genes involved in nearly every step of the biochemical pathway leading to non-shivering thermogenesis are significantly increased in BAT during hibernation, whereas those of genes involved in protein biosynthesis are significantly decreased compared to the summer active animals in August. The differentially expressed genes also include those involved in adipose differentiation, substrate transport, and structure remodeling, which may enhance thermogenesis at low tissue temperatures in BAT. Keywords: hibernating animals vs. summer active animals
Project description:miRNAs are 19-25 nucleotides long small RNAs now well-known for their regulatory roles in the development and diseases through post-transcriptional and translational controls in a wide range of species. Mammalian hibernation is a physiological process involving dramatic metabolic suppression and cellular reorganization, during which miRNAs may play an important role. We systematically analyzed the miRNAs in the liver of an extreme hibernating species, arctic ground squirrels (Spermophilus parryii), during two stages of hibernation compared to non-hibernating animals by massively parallel Illumina sequencing technology. We identified more than 200 ground squirrel miRNAs including novel miRNAs specific to ground squirrel and a fast-evolving miRNA cluster that also showed significant differential expression during hibernation. Integrating with Agilent miRNA microarray and Real-time PCR results, we identified that mir-211, mir-378, mir-184, mir-200a, and mir-320 were significantly under-expressed during hibernation, whereas mir-144, mir-486, mir-451, mir-142-5p, and mir-1 were over-expressed. Analyses of the their target genes suggested that these miRNAs could play an important role to suppress tumor progression and cell growth during hibernation. Investigation of microRNA changes in arctic ground squirrel livers during Early Arousal(EA), Late Topor(LT), and Post-Reproduction(PR) stages.
Project description:miRNAs are 19-25 nucleotides long small RNAs now well-known for their regulatory roles in the development and diseases through post-transcriptional and translational controls in a wide range of species. Mammalian hibernation is a physiological process involving dramatic metabolic suppression and cellular reorganization, during which miRNAs may play an important role. We systematically analyzed the miRNAs in the liver of an extreme hibernating species, arctic ground squirrels (Spermophilus parryii), during two stages of hibernation compared to non-hibernating animals by massively parallel Illumina sequencing technology. We identified more than 200 ground squirrel miRNAs including novel miRNAs specific to ground squirrel and a fast-evolving miRNA cluster that also showed significant differential expression during hibernation. Integrating with Agilent miRNA microarray and Real-time PCR results, we identified that mir-211, mir-378, mir-184, mir-200a, and mir-320 were significantly under-expressed during hibernation, whereas mir-144, mir-486, mir-451, mir-142-5p, and mir-1 were over-expressed. Analyses of the their target genes suggested that these miRNAs could play an important role to suppress tumor progression and cell growth during hibernation. Three total RNA pools from arctic ground squirrel livers in Early Arousal(EA), Late Topor(LT), and Post-Reproduction(PR) stages were hybridized to three Agilent mouse miRNA microarrays.
Project description:Dietary intake of fruits and vegetables (FV) has been inversely associated with lower risk of ulcerative colitis. A pig model was used to evaluate the impact of feeding FV on the host response to dextran sulfate sodium (DSS)-induced colitis. Methods: Six-week-old pigs were fed a grower diet alone or supplemented with lyophilized FV equivalent to the half (half-FV) or full (full-FV) daily levels recommended for humans by the Dietary Guidelines for Americans (DGA). Pigs were fed a 1) grower diet alone (negative control), 2) grower diet and orally treated with 4% DSS for 10 days to induce colitis (positive control), 3) half-FV diet treated with 4% DSS or 4) full-FV diet treated with 4% DSS. Pigs were monitored for the development of clinical signs of colitis. Proximal colon (PC) contents and mucosa (PCM) were collected for gut metagenome, tissue transcriptome and histopathological analysis. Results: Pigs fed the full-FV diet did not exhibit diarrhea, showed less fecal occult blood (FOB), PCM crypt hyperplasia but with no differential expressed genes (DEG) or changes in PC microbiome diversity (p < 0.05). Pigs within the half-FV group exhibited increased group FOB and DEG associated with tissue remodeling, crypt and goblet cell hyperplasia in the PCM and no changes in PC microbiome diversity and two pigs exhibiting diarrhea (p < 0.05). Pigs within the DSS positive control group exhibited a reduced DEG involved with intestinal immune response and PC microbiome diversity with altered metagenome, increased group PCM erosion and FOB with persistent diarrhea in one pig (p < 0.05) Conclusions: Overall, our results showed that pigs fed a three-week full-FV supplemented diet, were resistant to DSS-induced colitis with a differential dose-dependent protective effect on host intestinal tissue and gut metagenome when exposed to an inflammatory challenge.
Project description:The gut microbiota plays a vital role in maintaining the physiological function of host health and the pathogenesis of various diseases. However, its relationship with maternal age-associated decline in oocyte quality remains elusive. Here, we report that establishment of gut microbiota from young donors in aged mice by fecal microbiota transplantation (FMT) is an effective method to rejuvenate the quality of maternally aged oocytes. Specifically, young gut microbiota promoted the ovulation and maturation of aged oocytes, and inhibited occurrence of cytoplasm fragmentation and spindle/chromosome abnormalities, hence enhancing the oocyte quality and female fertility. By integrating metagenome and untargeted metabolome of intestinal digesta, as well as targeted metabolome of ovaries and micro-transcriptome of oocytes, we identified that Bacteroides_caecimuris-modulated glutamic acid levels mediated the restorative effects of young gut microbiota on the aged oocytes through strengthening the mitochondria function. In addition, we demonstrated that in vivo supplementation of glutamic acid also enhanced the quality of aged oocytes, and the improvement of oocyte quality by glutamic acid was conserved across species. Altogether, our findings highlight the importance of gut microbiota in the oocyte aging and provide potential improvement strategies for age-related decline in oocyte quality and female fertility.
Project description:The gut microbiota plays a vital role in maintaining the physiological function of host health and the pathogenesis of various diseases. However, its relationship with maternal age-associated decline in oocyte quality remains elusive. Here, we report that establishment of gut microbiota from young donors in aged mice by fecal microbiota transplantation (FMT) is an effective method to rejuvenate the quality of maternally aged oocytes. Specifically, young gut microbiota promoted the ovulation and maturation of aged oocytes, and inhibited occurrence of cytoplasm fragmentation and spindle/chromosome abnormalities, hence enhancing the oocyte quality and female fertility. By integrating metagenome and untargeted metabolome of intestinal digesta, as well as targeted metabolome of ovaries and micro-transcriptome of oocytes, we identified that Bacteroides_caecimuris-modulated glutamic acid levels mediated the restorative effects of young gut microbiota on the aged oocytes through strengthening the mitochondria function. In addition, we demonstrated that in vivo supplementation of glutamic acid also enhanced the quality of aged oocytes, and the improvement of oocyte quality by glutamic acid was conserved across species. Altogether, our findings highlight the importance of gut microbiota in the oocyte aging and provide potential improvement strategies for age-related decline in oocyte quality and female fertility.
Project description:The gut microbiota plays a vital role in maintaining the physiological function of host health and the pathogenesis of various diseases. However, its relationship with maternal age-associated decline in oocyte quality remains elusive. Here, we report that establishment of gut microbiota from young donors in aged mice by fecal microbiota transplantation (FMT) is an effective method to rejuvenate the quality of maternally aged oocytes. Specifically, young gut microbiota promoted the ovulation and maturation of aged oocytes, and inhibited occurrence of cytoplasm fragmentation and spindle/chromosome abnormalities, hence enhancing the oocyte quality and female fertility. By integrating metagenome and untargeted metabolome of intestinal digesta, as well as targeted metabolome of ovaries and micro-transcriptome of oocytes, we identified that Bacteroides_caecimuris-modulated glutamic acid levels mediated the restorative effects of young gut microbiota on the aged oocytes through strengthening the mitochondria function. In addition, we demonstrated that in vivo supplementation of glutamic acid also enhanced the quality of aged oocytes, and the improvement of oocyte quality by glutamic acid was conserved across species. Altogether, our findings highlight the importance of gut microbiota in the oocyte aging and provide potential improvement strategies for age-related decline in oocyte quality and female fertility.