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:MicroRNAs (miRNAs) play important roles by regulating the expression of target genes in plant and animal. However, little known about mechanism of fungal miRNA-like RNAs (milRNAs) regulating target gene restricts their functional exploration. In this study, multiple omics were used to identify the milRNAs and their target genes in a phytopathogenic fungus Valsa mali. Many candidate pathogenic factors were found to be regulated by milRNA-directed cleavage way. Absence or downregulated expression of Vm-milRNAs promote expression of candidate pathogenic factors during V. mali infection. Vm-milR16 is a significantly downregulated milRNA during V. mali infection, resulting in significantly upregulated expression of three target genes: VmSNF1, VmDODA, and VmHy1. Overexpression of Vm-milR16 significantly reduces the pathogenicity of V. mali. And all the three target genes of Vm-milR16 are required for the full pathogenicity of V. mali. Further analysis revealed that VmSNF1 regulates the pathogenicity by affecting the expression of pectinase genes during V. mali infection. And all the three target genes are essential for oxidative stress response during V. mali-host interaction. Vm-milRNAs may help V. mali to intelligently use limited resources and adaptively regulate pathogenicity by enhancing expression of pathogenic factors and fitness during infection.