Project description:Genome wide expression profiling to determine the overlap of Affymetrix-signals with SOLID sequencing RNA was extracted using the Qiagen RNeasy kit following the manufacturers guidelines, arrays were prepared and hybridized following the Affymetrix protocol. Mus musculus samples from small intestine and colon, to be compared to transcript data aquired with other techniques
Project description:The ketogenic diet has been successful in promoting weight loss among patients that have struggled with weight gain. This is due to the cellular switch in metabolism that utilizes liver-derived ketone bodies for the primary energy source rather than glucose. Fatty acid transport protein 2 (FATP2) is highly expressed in liver, small intestine, and kidney where it functions in both the transport of exogenous long chain fatty acids (LCFA) and in the activation to CoA thioesters of very long chain fatty acids (VLCFA). We have completed a multi-omic study of FATP2-null (Fatp2-/-) mice maintained on a ketogenic diet (KD) or paired control diet (CD), with and without a 24-hour fast (KD-fasted and CD-fasted) to address the impact of deleting FATP2 under high-stress conditions. Control (wt/wt) and Fatp2-/- mice were maintained on their respective diets for 4-weeks. Afterwards, half the population was sacrificed while the remaining were fasted for 24-hours prior to sacrifice. We then performed paired-end RNA-sequencing on the whole liver tissue to investigate differential gene expression. The differentially expressed genes mapped to ontologies such as the metabolism of amino acids and derivatives, fatty acid metabolism, protein localization, and components of the immune system’s complement cascade, and were supported by the proteome and histological staining.
Project description:Background: A recently developed animal model of the genetic disease is the cystic fibrosis (CF) rat, which similar to other animal models of CF exhibits a lethal intestinal phenotype. To begin characterizing the CF rat intestinal phenotype, we investigated global gene expression in the CF rat small intestine. Methods: Total RNA was extracted from full thickness of the entire small intestines of wild type (WT) and CF rats just before weaning. Results: There were 890 genes with significantly different expression levels (1.2-fold cutoff) comparing CF to wild type (WT), including 485 genes increased and 405 decreased in the CF intestine. The major pathways associated with these changes were inflammation, lipid metabolism, cytochrome P450-mediated degradative pathways, and cell growth/death. Comparison of the rat RNA-Seq dataset to earlier microarray analysis using a CFTR knockout mouse showed significant overlap with the CF rat small intestine. Conclusions: The small intestine of the new CF rat model exhibits numerous alterations in gene expression similar to other animal models of CF which indicate this will be an additional new model to study the gut effects CF.
Project description:Background: Cystic fibrosis (CF) is caused by mutations in the CFTR gene that impair function of this cAMP-regulated Cl- channel. In the small intestine, loss of CFTR function creates a dehydrated, acidic luminal environment which is believed to cause an accumulation of mucus, a phenotype characteristic of CF. CF mice have an innate immune response and impaired intestinal transit as well. We investigated whether lubiprostone, which activates the CLC2 Cl- channel, would improve the CF intestinal phenotype. Methods: Cftrtm1UNC (CF) and wildtype (WT) littermate mice on the C57BL/6 background were used. Lubiprostone (10ug/kg-day) was administered by gavage for two weeks. Mucus accumulation was estimated from crypt lumen widths in Carnoy's-fixed, PAS/AB stained sections. Luminal bacterial load was measured by qPCR for the bacterial 16S gene. Gastric emptying and small intestinal transit were assessed by gavage of rhodamine dextran. Gene expression was evaluated by Affymetrix Mouse430 2.0 microarray. Results: Crypt width in control CF mice was 700% that of WT mice (P<0.001). Lubiprostone did not affect WT crypt width but, unexpectedly, increased CF crypt width 22% (P=0.001). Lubiprostone increased bacterial load in WT mice to 490% of WT control levels (P=0.008). Conversely, lubiprostone decreased bacterial overgrowth in CF mice by 60% (P=0.005). Lubiprostone significantly increased gastric emptying at 20 min postgavage in both WT (P<0.001; control=57±3%, treated=81±4%) and CF mice (P<0.001; control=48±4%, treated=75±5%). After lubiprostone small intestinal transit was significantly enhanced in WT mice (P=0.024) but the effect was not significant in CF mice (P=0.377). Among other innate immune markers, expression of mast cell genes was elevated ~20-fold in the control CF intestine and lubiprostone decreased expression to WT control levels. Conclusions: These results indicate that lubiprostone has some benefits for the CF intestinal phenotype, especially on bacterial overgrowth and the innate immune response. The unexpected observation of increased mucus accumulation in the crypts of lubiprostone-treated CF mice suggests the possibility that lubiprostone increases mucus secretion. For each group (control wild type, lubiprostone-treated wild type, contol Cftr null, and lubiprostone-treated cftr null), equal amounts of total RNA extracted from the entire small intestine were pooled for analysis.