Abstract: 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 SamplesIPH-926 is an anticancer drug-resistant tumor cell line derived from a chemo-refractory human infiltrating lobular breast cancer (ILBC). IPH-926 ILBC cells were subjected to gene expression profiling using an Affymetrix HG U133 Plus 2.0 array.
ABCB1/MDR1 contributes to the anticancer drug-resistant phenotype of IPH-926 human lobular breast cancer cells.
Specimen part, Cell line
View SamplesHuman solid tumors contain rare cancer side population (SP) cells, which expel the fluorescencent dye H33342 and display cancer stem cell characteristics. Transcriptional profiling of cancer SP cells isolated by H33342 fluorescence analysis is a newly emerging approach to discover cancer stem cell markers and aberrant differentiation pathways. Using Affymetrix expression microarrays this study investigated differential gene expression between SP and non-SP (NSP) cells isolated from the CAL-51 human mammary carcinoma cell line.
Down-regulation of the fetal stem cell factor SOX17 by H33342: a mechanism responsible for differential gene expression in breast cancer side population cells.
Specimen part
View SamplesWe used transcription-profiling to identify mitogen-activated protein kinase (Mapk) signaling as an important regulator involved in the differentiation of oligodendrocyte progenitor cells (OPCs) into oligodendrocytes. We show in tissue culture that activation of Mapk signaling by elevation of intracellular levels of cAMP using administration of either dibutyryl-cAMP or inhibitors of the cAMP-hydrolyzing enzyme phosphodiesterase-4 (Pde4) enhances OPC differentiation. Finally, we demonstrate that systemic delivery of a Pde4 inhibitor leads to enhanced differentiation of OPCs within focal areas of toxin-induced demyelination and a consequent acceleration of remyelination.
Retinoid X receptor gamma signaling accelerates CNS remyelination.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Characterization of genomic imbalances in diffuse large B-cell lymphoma by detailed SNP-chip analysis.
Sex, Age
View SamplesThe pathogenesis of diffuse large B cell lymphomas (DLBCL) is only partly understood. We analyzed 148 DLBCL by high resolution single nucleotide polymorphism (SNP)-chips to characterize genomic imbalances. Seventy-nine cases were of the germinal center B-cell like (GCB) type of DLBCL, 49 of the activated B-cell like (ABC) subtype and 20 were type 3 DLBCL. Twenty-four regions of recurrent genomic gains and 38 regions of recurrent genomic losses were identified over the whole cohort, with a median of 25 imbalances per case for ABC-DLBCL and 19 per case for GCB-DLBCL. Several recurrent copy number changes showed differential frequencies in the GCB- and ABC-DLBCL subgroups, including gains of HDAC7A predominantly in GCB-DLBCL (38% of cases) and losses of BACH2 and CASP8AP2 predominantly in ABC-DLBCL (35%), hinting at disparate pathogenetic mechanisms in these entities. Correlating gene expression and copy number revealed a strong gene dosage effect in all tumors, with 34% of probesets showing a concordant expression change in affected regions. Two new potential tumor suppressor genes emerging from the analysis, CASP3 and IL5RA, were sequenced in 10 and 16 candidate cases, respectively. However, no mutations were found, pointing to a potential haploinsufficiency effect of these genes, considering their reduced expression in cases with deletions. This work thus describes differences and similarities in the landscape of genomic aberrations in the DLBCL subgroups in a large collection of cases, confirming already known targets, but also discovering novel copy number changes with possible pathogenetic relevance.
Characterization of genomic imbalances in diffuse large B-cell lymphoma by detailed SNP-chip analysis.
Sex, Age
View SamplesHair follicle formation depends on reciprocal epidermal-dermal interactions and occurs during skin development, but not in adult life. This suggests that the properties of dermal fibroblasts change during postnatal development. To examine this, we used a PdgfraEGFP mouse line to isolate GFP-positive fibroblasts from neonatal skin, adult telogen and anagen skin and adult skin in which ectopic hair follicles had been induced (EF skin) by transgenic epidermal activation of beta-catenin. We also isolated epidermal cells from each mouse. The gene expression profile of EF epidermis was most similar to that of anagen epidermis, consistent with activation of beta-catenin signalling. In contrast, adult dermis with ectopic hair follicles more closely resembled neonatal dermis than adult telogen or anagen dermis. In particular, genes associated with mitosis were upregulated and extracellular matrix-associated genes were downregulated in neonatal and EF fibroblasts. We confirmed that sustained epidermal beta-catenin activation stimulated fibroblasts to proliferate to reach the high cell density of neonatal skin. In addition, the extracellular matrix was comprehensively remodelled, with mature collagen being replaced by collagen subtypes normally present only in developing skin. The changes in proliferation and extracellular matrix composition originated from a specific subpopulation of fibroblasts located beneath the sebaceous gland. Our results show that adult dermis is an unexpectedly plastic tissue that can be reprogrammed to acquire the molecular, cellular and structural characteristics of neonatal dermis in response to cues from the overlying epidermis.
Reprogramming adult dermis to a neonatal state through epidermal activation of β-catenin.
No sample metadata fields
View SamplesBefore and after anaerobic Fe(II) shocked WT and ?bqsR of late stationary phase P. aeruginosa PA14 strains Associated publication: Kreamer NN, Costa F, Newman DK. 2015. The ferrous iron-responsive BqsRS two-component system activates genes that promote cationic stress tolerance. mBio 6(1):e02549-14. doi:10.1128/mBio.02549-14. Overall design: Expression profiles of rRNA-depleted total RNA from WT and ?bqsR Fe(II)-shocked (before and after 30 min incubation with 200 µM ferrous ammonium sulfate ) cultures grown anaerobically to deep stationary phase (A500 = 0.8) in Fe-limited (1 µM ferrous ammonium sulfate) MOPS minimal medium containing succinate as the carbon source, in triplicate
The ferrous iron-responsive BqsRS two-component system activates genes that promote cationic stress tolerance.
Cell line, Subject
View SamplesIn deceased donor kidney transplantation, acute kidney injury (AKI) prioir to surgery is a major determinant of delayed graft function (DGF), but AKI is histologically silent and difficult to assess. We hypothesized that a molecular measurement of AKI would add power to conventional risk assessments to predict the early poor allograft function at first week post transplantation.
Comparing molecular assessment of implantation biopsies with histologic and demographic risk assessment.
Specimen part
View Samples