The gastrointestinal (GI) tract can have significant impact on the regulation of the whole body metabolism and may contribute to the development of obesity and diabetes. To systemically elucidate the role of the GI tract in obesity, we performed a transcriptomic analyses in different parts of the GI tract of two obese mouse models: ob/ob and high-fat diet (HFD) fed mice. Compared to their lean controls, both obese mouse groups had significant amount of gene expression changes in the stomach (ob/ob: 959; HFD: 542), much more than the number of changes in the intestine. Despite the difference in genetic background, the two mouse models shared 296 similar gene expression changes in the stomach. Among those genes, some had known associations to obesity, diabetes and insulin resistance. In addition, the gene expression profile strongly suggested an increased gastric acid secretion in both obese mouse models, probably through an activation of the gastrin pathway. In conclusion, our data reveal a previously unknown dominant connection between the stomach and obesity.
Significant obesity-associated gene expression changes occur in the stomach but not intestines in obese mice.
Specimen part
View SamplesCholecystokinin (CCK) is a satiety hormone produced by discrete enteroendocrine cells scattered among absorptive cells of the small intestine. CCK is released into blood following a meal; however, the mechanisms inducing hormone secretion are largely unknown. Ingested fat is the major stimulant of CCK secretion. We recently identified a novel member of the lipoprotein remnant receptor family known as immunoglobulin-like domain containing receptor 1 (ILDR1) in intestinal CCK cells and postulated that this receptor conveyed the signal for fat-stimulated CCK secretion. In the intestine, ILDR1 is expressed exclusively in CCK cells. Orogastric administration of fatty acids elevated blood levels of CCK in wild type but not ILDR1-deficient mice, although the CCK secretory response to trypsin inhibitor was retained. The uptake of fluorescently labeled lipoproteins in ILDR1-transfected CHO cells and release of CCK from isolated intestinal cells required a unique combination of fatty acid plus HDL. CCK secretion secondary to ILDR1 activation is associated with increased [Ca2+]i consistent with regulated hormone release. These findings demonstrate that ILDR1 regulates CCK release through a mechanism dependent on fatty acids and lipoproteins and that absorbed fatty acids regulate gastrointestinal hormone secretion.
Immunoglobulin-like domain containing receptor 1 mediates fat-stimulated cholecystokinin secretion.
Specimen part
View SamplesWe developed a mouse model that captures radiation effects on host biology by transplanting unirradiated Trp53 null mammary tissue to sham or irradiated hosts. Gene expression profiles of tumors that arose in irradiated mice are distinct from those that arose in nave hosts.
Murine microenvironment metaprofiles associate with human cancer etiology and intrinsic subtypes.
Specimen part
View SamplesThe transcription factor Nkx2.5 is required for specification of pharyngeal arch second heart field (SHF) progenitors that contribute to outflow tract (OFT) and right ventricle (RV) formation. Multiple sets of microarray data were analyzed to identify genes that are candidate targets of Nkx2.5 in the second heart field. These sets are: 1) publicly available data for cardiothoracic tissue from E9.5 Nkx2.5 wild-type, heterozygous and homozygous embryos; 2) an analysis of mouse E10.5 pharyngeal arch tissue; 3) an analysis of mouse E12.5 heart tissue; and 4) a temporal analysis of the cardiogenic cell line P19CL6. This combined analysis identified 11 genes (Lrrn1, Elovl2, Safb, Slc39a6, Khdrbs1, Hoxb4, Fez1, Ccdc117, Jarid2, Nrcam, and Enpp3) expressed in SHF-containing pharyngeal arch tissue whose regulation is dependent on Nkx2.5 expression.
Jarid2 is among a set of genes differentially regulated by Nkx2.5 during outflow tract morphogenesis.
Specimen part, Cell line
View SamplesPluripotent P19CL6 embryonic carcinoma cells can be differentiated to a cardiac lineage by culture in the presence of DMSO. The goal of this study was to characterize temporal gene expression patterns associated with cardiogenic differentiation. Gene expression analysis was conducted on differentiating P19CL6 cells at several time points following induction with 1% DMSO. Samples were processed for analysis by Affymetrix GeneChip.
Jarid2 is among a set of genes differentially regulated by Nkx2.5 during outflow tract morphogenesis.
Cell line
View SamplesWe propose comparing liver gene expression of WT and female ERKO mice early in the high-fat feeding period to animals fed a regular chow diet. Analyzing liver tissue before the fatty liver disease phenotype becomes severe will allow identification of target genes which may be causal.
Hormone signaling and fatty liver in females: analysis of estrogen receptor α mutant mice.
Sex, Specimen part
View SamplesUnderstanding the response of memory CD8 T cells to persistent antigen re-stimulation and the role of CD4 T cell help is critical to the design of successful vaccines for chronic diseases. However, studies comparing the protective abilities and qualities of memory and nave cells have been mostly performed in acute infections, and little is known about their roles during chronic infections. Herein, we show that memory cells dominate over nave cells and are protective when present in large enough numbers to quickly reduce infection. In contrast, when infection is not rapidly reduced, memory cells are quickly lost, unlike nave cells. This loss of memory cells is due to (i) an early block in cell proliferation, (ii) selective regulation by the inhibitory receptor 2B4, and (iii) increased reliance on CD4 T cell help. These findings have important implications towards the design of T cell vaccines against chronic infections and tumors.
Tight regulation of memory CD8(+) T cells limits their effectiveness during sustained high viral load.
Specimen part
View SamplesThe Toll-like receptor 4 (TLR4) pathway is important for tumor-initiating cells. We used microarrays to obtain gene profiling data in order to increase understanding of the pathways.
Reciprocal regulation by TLR4 and TGF-β in tumor-initiating stem-like cells.
Sex, Specimen part
View SamplesThe role of the renin-angiotensin system in chronic kidney disease involves multiple peptides and receptors. Exerting antipodal pathophysiological mechanisms, renin inhibition and AT1 antagonism ameliorate renal damage.
AT1 antagonism and renin inhibition in mice: pivotal role of targeting angiotensin II in chronic kidney disease.
Age, Specimen part, Treatment
View SamplesAffymetrix Human Gene 1.1 ST Array profiling of 285 primary medulloblastoma samples.
Subgroup-specific structural variation across 1,000 medulloblastoma genomes.
Sex, Age
View Samples