Project description:Numerous cytokines have been shown to affect epithelial cell differentiation and proliferation through epithelial-mesenchymal interaction. Growing evidence suggests that platelet-derived growth factor (PDGF) signaling is an important mediator of these interactions. The purpose of this study was to evaluate the effect of PDGF-α on enterocyte turnover in a rat model of short bowel syndrome (SBS). Male rats were divided into four groups: Sham rats underwent bowel transection, Sham-PDGF-α rats underwent bowel transection and were treated with PDGF-α, SBS rats underwent a 75% bowel resection, and SBS-PDGF-α rats underwent bowel resection and were treated with PDGF-α. Parameters of intestinal adaptation, enterocyte proliferation and apoptosis were determined at sacrifice. Illumina's Digital Gene Expression (DGE) analysis was used to determine PDGF-related gene expression profiling. PDGF-α and PDGF-α receptor (PDGFR-α) expression was determined using Real Time PCR. Western blotting was used to determine p-ERK, Akt1/2/3, bax and bcl-2 protein levels. SBS rats demonstrated a significant increase in PDGF-α and PDGFR-α expression in jejunum and ileum compared to sham animals. SBS-PDGF-α rats demonstrated a significant increase in bowel and mucosal weight, villus height and crypt depth in jejunum and ileum compared to SBS animals. PDGF-α expression in crypts increased in SBS rats (vs sham) and was accompanied by increased cell proliferation following PDGF-α administration. A significant decrease in cell apoptosis in this group was correlated with lower bax protein levels. In conclusion, in a rat model of SBS, PDGF-α stimulates enterocyte turnover, which is correlated with up-regulated PDGF-α receptor expression in the remaining small intestine. Animals were divided randomly into two experimental groups of 6 rats each. Group A rats underwent bowel transection and re-anastomosis (Sham), Group B animals underwent 75% bowel resection (SBS). Due to the quality of DNA, we performed final analysis from 5 jejunal samples (1 sham and 4 resected rats) and from 7 ileal samples (3 sham and 4 resected rats). Illumina's Digital Gene Expression (DGE) analysis using Illumina Rat Quad BeadChips was used to determine PDGF-related gene expression profiling.
Project description:Numerous cytokines have been shown to affect epithelial cell differentiation and proliferation through epithelial-mesenchymal interaction. Growing evidence suggests that platelet-derived growth factor (PDGF) signaling is an important mediator of these interactions. The purpose of this study was to evaluate the effect of PDGF-α on enterocyte turnover in a rat model of short bowel syndrome (SBS). Male rats were divided into four groups: Sham rats underwent bowel transection, Sham-PDGF-α rats underwent bowel transection and were treated with PDGF-α, SBS rats underwent a 75% bowel resection, and SBS-PDGF-α rats underwent bowel resection and were treated with PDGF-α. Parameters of intestinal adaptation, enterocyte proliferation and apoptosis were determined at sacrifice. Illumina's Digital Gene Expression (DGE) analysis was used to determine PDGF-related gene expression profiling. PDGF-α and PDGF-α receptor (PDGFR-α) expression was determined using Real Time PCR. Western blotting was used to determine p-ERK, Akt1/2/3, bax and bcl-2 protein levels. SBS rats demonstrated a significant increase in PDGF-α and PDGFR-α expression in jejunum and ileum compared to sham animals. SBS-PDGF-α rats demonstrated a significant increase in bowel and mucosal weight, villus height and crypt depth in jejunum and ileum compared to SBS animals. PDGF-α expression in crypts increased in SBS rats (vs sham) and was accompanied by increased cell proliferation following PDGF-α administration. A significant decrease in cell apoptosis in this group was correlated with lower bax protein levels. In conclusion, in a rat model of SBS, PDGF-α stimulates enterocyte turnover, which is correlated with up-regulated PDGF-α receptor expression in the remaining small intestine.
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:Long-term dietary intake influences the structure and activity of the trillions of microorganisms residing in the human gut, but it remains unclear how rapidly and reproducibly the human gut microbiome responds to short-term macronutrient change. Here we show that the short-term consumption of diets composed entirely of animal or plant products alters microbial community structure and overwhelms inter-individual differences in microbial gene expression. The animal-based diet increased the abundance of bile-tolerant microorganisms (Alistipes, Bilophila and Bacteroides) and decreased the levels of Firmicutes that metabolize dietary plant polysaccharides (Roseburia, Eubacterium rectale and Ruminococcus bromii). Microbial activity mirrored differences between herbivorous and carnivorous mammals, reflecting trade-offs between carbohydrate and protein fermentation. Foodborne microbes from both diets transiently colonized the gut, including bacteria, fungi and even viruses. Finally, increases in the abundance and activity of Bilophila wadsworthia on the animal-based diet support a link between dietary fat, bile acids and the outgrowth of microorganisms capable of triggering inflammatory bowel disease. In concert, these results demonstrate that the gut microbiome can rapidly respond to altered diet, potentially facilitating the diversity of human dietary lifestyles. RNA-Seq analysis of the human gut microbiome during consumption of a plant- or animal-based diet.