Acute kidney injury (AKI) is associated with an abrupt loss of kidney function that results in significant morbidity and mortality. Considerable effort has focused around the identification of diagnostic biomarkers and the analysis of molecular events. Most studies have adopted organ-wide approaches that do not fully capture the interplay among different cell types in the pathophysiology of AKI. To extend our understanding of molecular and cellular events in AKI, we developed a mouse line that enables the identification of translational profiles in specific cell types by CRE recombinase-dependent activation of an eGFP-tagged L10a ribosomal protein subunit, and consequently, translating ribosome affinity purification (TRAP) of mRNA populations. By utilizing cell-type specific CRE-driver lines, in this study we identify distinct cellular responses in an ischemia reperfusion injury (IRI) model of AKI. Cell-specific translational expression profiles were uncovered 24 hours after IRI from four populations enriched for distinct anatomical and cellular subgroups: nephron, interstitial cell populations, vascular endothelium, and macrophages/monocytes by Affymetrix microarray.
Cell-specific translational profiling in acute kidney injury.
Sex, Age, Specimen part, Treatment
View SamplesThe long term goal is to define the transcriptional changes that accompany pericyte-to-myofibroblast transition in fibrotic kidney disease. Medullary pericytes are identified by their expression of a eGFPL10a fusion protein whose expression is driven by a Col1a1 promoter. Pericyte-specific RNA is generated by eGFP-affinity purification of polysomes from medullary lysates and then subject to microarray analysis.
Translational profiles of medullary myofibroblasts during kidney fibrosis.
Sex, Specimen part, Time
View SamplesWe used high density oligonucleotide arrays to identify molecular correlates of genetically and clinically distinct subgroups of B-cell chronic lymphocytic leukemia (B-CLL). Gene expression profiling was used to profile the five most frequent genomic aberrations, namely deletions affecting chromosome bands 13q14, 11q22-q23, 17p13 and 6q21, and gains of genomic material affecting chromosome band 12q13. A strikingly high degree of correlation between loss or gain of genomic material and the amount of transcripts from the affected regions leads to the hypothesis of gene dosage as a significant pathogenic factor. Furthermore, the influence of the immunoglobulin variable heavy chain (VH) mutation status was determined. A clear distinction in the expression profiles of unmutated and mutated VH samples exists, which can be discovered using unsupervised learning methods. However, when samples were separated by gender, this separation could only be detected in samples from male patients.
Microarray gene expression profiling of B-cell chronic lymphocytic leukemia subgroups defined by genomic aberrations and VH mutation status.
No sample metadata fields
View SamplesRecently, the p53-miR-34a network was identified to play an important role in tumorigenesis. As in acute myeloid leukemia with complex karyotype (CK-AML) TP53 alterations are the most common known molecular lesion, we further analyzed the p53-miR-34a axis in CK-AML with known TP53 status. Clinically, low miR-34a expression and TP53 alterations predicted for chemotherapy resistance and inferior outcome. Notably, in TP53unaltered CK-AML high miR-34a expression predicted for inferior overall survival (OS), whereas in TP53biallelic altered CK-AML high miR-34a expression pointed to better OS.
Altered miRNA and gene expression in acute myeloid leukemia with complex karyotype identify networks of prognostic relevance.
Disease
View SamplesAbstract: Histones are small proteins that form the core of nucleosomes, around which eukaryotic DNA wraps to ultimately form the highly organized and compressed structure known as chromatin. The N-terminal tails of histones are highly modified, and the modification state of these proteins dictates whether chromatin is permissive or repressive to processes that require physical access to DNA, including transcription and DNA replication and repair. The enzymes that add and remove histone modifications are known to be exquisitely sensitive to endogenous small molecule metabolite availability. In this manner, chromatin can adapt to changes in environment, particularly diet-induced metabolic state. Importantly, gut microbiota contribute to robust host metabolic phenotypes, and produce a myriad of metabolites that are detectable in host circulation. Further, gut microbial community composition and metabolite production are regulated by host diet, as a major source of carbon and energy for the microbiota. While prior studies have reported robust host metabolic associations with gut microbiota, the mechanisms therein remain largely unknown. Here we demonstrate that microbial colonization regulates global histone acetylation and methylation in multiple host tissues including colon, adipose tissue, and liver. This regulatory relationship is altered by diet: a “Western-type” diet leads to a general suppression of the microbiota-dependent chromatin changes observed in a polysaccharide rich diet. Finally, we demonstrate that supplementation of germ-free mice with major products of gut bacterial fermentation (i.e., short-chain fatty acids acetate, propionate, and butyrate) is sufficient to recapitulate many of the effects of colonization on host epigenetic states. These findings have profound implications for understanding the complex functional interactions between diet, gut microbiota, and host health. Overall design: 15 samples in total (biological n=3 per for each of 5 conditions; 19kw old male C57BL/6J mouse liver): (1) GF mouse liver on chow diet, (2) ConvR mouse liver on chow diet, (3) ConvD mouse liver on chow diet, (4) GF mouse liver on HF/HS diet, (5) ConvR mouse liver on HF/HS diet
Diet-Microbiota Interactions Mediate Global Epigenetic Programming in Multiple Host Tissues.
Cell line, Subject
View SamplesAbstract: Histones are small proteins that form the core of nucleosomes, around which eukaryotic DNA wraps to ultimately form the highly organized and compressed structure known as chromatin. The N-terminal tails of histones are highly modified, and the modification state of these proteins dictates whether chromatin is permissive or repressive to processes that require physical access to DNA, including transcription and DNA replication and repair. The enzymes that add and remove histone modifications are known to be exquisitely sensitive to endogenous small molecule metabolite availability. In this manner, chromatin can adapt to changes in environment, particularly diet-induced metabolic state. Importantly, gut microbiota contribute to robust host metabolic phenotypes, and produce a myriad of metabolites that are detectable in host circulation. Further, gut microbial community composition and metabolite production are regulated by host diet, as a major source of carbon and energy for the microbiota. While prior studies have reported robust host metabolic associations with gut microbiota, the mechanisms therein remain largely unknown. Here we demonstrate that microbial colonization regulates global histone acetylation and methylation in multiple host tissues including colon, adipose tissue, and liver. This regulatory relationship is altered by diet: a “Western-type” diet leads to a general suppression of the microbiota-dependent chromatin changes observed in a polysaccharide rich diet. Finally, we demonstrate that supplementation of germ-free mice with major products of gut bacterial fermentation (i.e., short-chain fatty acids acetate, propionate, and butyrate) is sufficient to recapitulate many of the effects of colonization on host epigenetic states. These findings have profound implications for understanding the complex functional interactions between diet, gut microbiota, and host health. Overall design: 9 samples in total (biological n=3 per for each of 3 conditions; 14kw old male C57BL/6J mouse liver): (1) GF mouse liver on chow diet, (2) ConvD mouse liver on chow diet, (3) GF mouse liver on chow diet + supplemented drinking water with short chain fatty acids
Diet-Microbiota Interactions Mediate Global Epigenetic Programming in Multiple Host Tissues.
Cell line, Subject
View SamplesA previously predictive CEBPA double mutant (CEBPAdm) signature was hampered by the recently reported CEBPA silenced AML cases that carry a similar gene expression profile (GEP). Two independent AML cohorts were used to train and evaluate the predictive value of the CEBPAdm signature in terms of sensitivity and specificity. A predictive signature was created, containing 25-probe sets by using a logistic regression model with Lasso regularization, which selects discriminative probe sets between the classes, CEBPAdm and all other AML cases, CEBPA wild type (CEBPAwt) and CEBPA single mutant (CEBPAsm). Subsequently, a classifier was trained on the entire HOVON-SAKK cohort based on a two-class approach; CEBPAdm versus all other cases (CEBPAwt and CEBPAsm). This trained classifier subsequently classified 16 candidate CEBPAdm cases in the AMLSG-cohort out of 154 AML cases. This approach showed perfect sensitivity and specificity (both 100%). In addition, we have performed a classification between CEBPAdm ,CEBPAsm, and CEBPAwt to infer if we were able to accurately classify CEBPAsm cases. We observed that all CEBPAsm cases were classified as CEBPAwt, thus CEBPAsm cases do not have a consistent gene expression pattern and are different from the CEBPAdm group.
Prognostic impact, concurrent genetic mutations, and gene expression features of AML with CEBPA mutations in a cohort of 1182 cytogenetically normal AML patients: further evidence for CEBPA double mutant AML as a distinctive disease entity.
No sample metadata fields
View SamplesTranscriptional responses to stimuli are regulated by tuning rates of transcript production and degradation. Here we show that stimulation-induced changes in transcript production and degradation rates can be inferred from simultaneously measured precursor mRNA (pre-mRNA) and mature mRNA profiles. Our studies on the transcriptome-wide responses to extracellular stimuli in different cellular model systems revealed hitherto unanticipated dynamics of transcript production and degradation rates. Intriguingly, genes with similar mRNA profiles often exhibit marked differences in the amplitude and onset of their production. Moreover, we identify a group of genes, which take advantage of the unexpectedly large dynamic range of production rates to expedite their induction by a transient production overshoot. These findings provide an unprecedented quantitative view on processes governing transcriptional responses, and may have broad implications for understanding their regulation at the transcriptional and post-transcriptional levels.
Coupled pre-mRNA and mRNA dynamics unveil operational strategies underlying transcriptional responses to stimuli.
Cell line, Treatment
View SamplesBackground: Humans with metabolic and inflammatory diseases frequently harbor lower levels of butyrate-producing bacteria in their gut. However, it is not known whether variation in the levels of these organisms is causally linked with disease development and whether diet modifies the impact of these bacteria on health. Results: We use germ-free apolipoprotein E-deficient mice colonized with synthetic microbial communities that differ in their capacity to generate butyrate to demonstrate that Roseburia intestinalis interacts with dietary components to (i) impact gene expression in the intestine, directing metabolism away from glycolysis and toward fatty acid utilization, (ii) improve intestinal barrier function, (iii) lower systemic inflammation and (iv) ameliorate atherosclerosis. Furthermore, intestinal administration of butyrate improves gut barrier function and reduces atherosclerosis development. Conclusions: Altogether, our results illustrate how modifiable diet-by-microbiota interactions impact cardiovascular disease, and suggest that interventions aimed at increasing the representation of butyrate-producing bacteria may provide protection against atherosclerosis. Overall design: Intestinal mRNA profiles of gnotobiotic ApoE KO mice colonized with "core" community or "core plus Roseburia intestinalis" were generated by deep sequencing using Illumina HiSeq.
Interactions between Roseburia intestinalis and diet modulate atherogenesis in a murine model.
Age, Specimen part, Subject
View SamplesInterleukin-10 (IL-10) is a pleiotropic anti-inflammatory cytokine produced and sensed by most hematopoietic cells. Genome wide association studies and experimental animal models point at a central role of the IL-10 axis in Inflammatory Bowel Diseases. Here we investigated the importance of intestinal macrophage production of IL-10 and their IL-10 exposure, as well as the existence of an IL-10-based autocrine regulatory loop in the gut. Specifically, we generated mice harboring IL-10 or IL-10 receptor (IL-10R) mutations in intestinal lamina propria-resident chemokine receptor CX3CR1hi-expressingmacrophages. We found macrophage-derived IL-10 dispensable for gut homeostasis and maintenance of colonic T regulatory cells. In contrast, loss of IL-10 receptor expression impaired the critical conditioning of these monocyte-derived macrophages, but resulted in spontaneous development of severe colitis. Collectively, our results highlight IL-10 as a critical homeostatic macrophage-conditioning factor in the colon and define intestinal CX3CR1hi macrophages as a decisive factor that determines gut health or inflammation.
Macrophage-restricted interleukin-10 receptor deficiency, but not IL-10 deficiency, causes severe spontaneous colitis.
Age, Specimen part
View Samples