Background: Breastfed human infants are predominantly colonized by bifidobacteria that thrive on human milk oligosaccharides (HMO). The two most predominant species of bifidobacteria in infant feces are Bifidobacterium breve (B. breve) and Bifidobacterium longum subsp. infantis (B. infantis), both avid HMO-consumer strains. Our laboratory has previously shown that B. infantis, when grown on HMO, increase adhesion to intestinal cells and increase the expression of the anti-inflammatory cytokine interleukin-10. The purpose of the current study was to investigate the effects of carbon source—glucose, lactose, or HMO—on the ability of B. breve and B. infantis to adhere to and affect the transcription of intestinal epithelial cells on a genome-wide basis. Results: HMO-grown B. infantis had higher percent binding to Caco-2 cell monolayers compared to B. infantis grown on glucose or lactose. B. breve had low adhesive ability regardless of carbon source. Despite differential binding ability, both HMO-grown strains significantly differentially affected the Caco-2 transcriptome compared to their glucose or lactose grown controls. HMO-grown B. breve and B. infantis both down-regulated genes in Caco-2 cells associated with chemokine activity. Conclusion: The choice of carbon source affects the interaction of bifidobacteria with intestinal epithelial cells. HMO-grown bifidobacteria reduce markers of inflammation, compared to glucose or lactose-grown bifidobacteria. In the future, the design of preventative or therapeutic probiotic supplements may need to include appropriately chosen prebiotics. Overall design: CACO-2 cells incubated with Bifidobacterium longum subsp. infantis grown on (1) glucose, (2) lactose, or (3) human milk oligosaccharides. All experiments were run in triplicate.
Bifidobacteria grown on human milk oligosaccharides downregulate the expression of inflammation-related genes in Caco-2 cells.
No sample metadata fields
View SamplesBackground: Breastfed human infants are predominantly colonized by bifidobacteria that thrive on human milk oligosaccharides (HMO). The two most predominant species of bifidobacteria in infant feces are Bifidobacterium breve (B. breve) and Bifidobacterium longum subsp. infantis (B. infantis), both avid HMO-consumer strains. Our laboratory has previously shown that B. infantis, when grown on HMO, increase adhesion to intestinal cells and increase the expression of the anti-inflammatory cytokine interleukin-10. The purpose of the current study was to investigate the effects of carbon source—glucose, lactose, or HMO—on the ability of B. breve and B. infantis to adhere to and affect the transcription of intestinal epithelial cells on a genome-wide basis. Results: HMO-grown B. infantis had higher percent binding to Caco-2 cell monolayers compared to B. infantis grown on glucose or lactose. B. breve had low adhesive ability regardless of carbon source. Despite differential binding ability, both HMO-grown strains significantly differentially affected the Caco-2 transcriptome compared to their glucose or lactose grown controls. HMO-grown B. breve and B. infantis both down-regulated genes in Caco-2 cells associated with chemokine activity. Conclusion: The choice of carbon source affects the interaction of bifidobacteria with intestinal epithelial cells. HMO-grown bifidobacteria reduce markers of inflammation, compared to glucose or lactose-grown bifidobacteria. In the future, the design of preventative or therapeutic probiotic supplements may need to include appropriately chosen prebiotics. Overall design: CACO-2 cells incubated with Bifidobacterium breve grown on (1) glucose, (2) lactose, or (3) human milk oligosaccharides. All experiments were run in triplicate.
Bifidobacteria grown on human milk oligosaccharides downregulate the expression of inflammation-related genes in Caco-2 cells.
No sample metadata fields
View SamplesThe functioning of a specific tissue depends on the expression pattern of the different genes. We used microarrays to compare gene expression across different murine tissues, to get a better understanding in the expression pattern and functioning of the different tissues. With this analysis, we were not only able to identify genes that were specifically expressed in a spicific tissue but, as important, we also identified genes that were specifically repressed in a tissue, compared to al the other analysed tissues.
Tissue-specific disallowance of housekeeping genes: the other face of cell differentiation.
Sex, Specimen part
View SamplesWe used Affymetrix Gene Arrays (1.0 ST) to compare gene expression across different murine tissues.
Tissue-specific disallowance of housekeeping genes: the other face of cell differentiation.
Specimen part
View SamplesSpiroplasma (Mollicutes) is one of the heritable bacterial endosymbionts of Drosophila species. Several strains like S. poulsonii manipulate host reproduction in a selfish manner. When females of D. melanogaster are infected with natural S. poulsonii strain MSRO (melanogaster sex ratio organism), only male offspring are killed during embryogenesis, and this phenomenon is called male-killing. To understand the molecular mechanism of male-killing, we compared gene expression profiles between MSRO-infected and uninfected embryos of D. melanogaster by using RNA-sequencing (RNA-seq). For embryonic sexing, we employed a transgenic reporter strain Sex-lethal (Sxl)-Pe-EGFP, which expresses GFP only in females. We collected female and male embryos at stage 10-11, when abnormal apoptosis associated with male-killing starts to occur in male progenies. For each sample, we analyzed three biological replicates.
Male-killing symbiont damages host's dosage-compensated sex chromosome to induce embryonic apoptosis.
No sample metadata fields
View SamplesBackground Alternative splicing (AS) is a central mechanism of genetic regulation which modifies the sequence of RNA transcripts in higher eukaryotes. AS has been shown to increase both the variability and diversity of the cellular proteome by changing the composition of resulting proteins through differential choice of exons to be included in mature mRNAs. Results In the present study, alterations to the global RNA splicing landscape of cellular genes upon viral infection were investigated through high-throughput RNA sequencing (RNA-seq) studies using mammalian reovirus as a model. Our study provides the first comprehensive portrait of global changes in the RNA splicing signatures that occur in eukaryotic cells following infection with a human virus. We identify modifications in the AS patterns of 240 cellular transcripts frequently involved in the regulation of gene expression and RNA metabolism. A significant number of the modified transcripts are also encoded by genes with important roles in viral infection/immunity. These modifications are expected to alter the functions of many cellular proteins. Finally, we used RT-PCR analysis in order to experimentally validate differential modifications in alternative splicing patterns that were observed through RNA-seq studies. Conclusion The present study demonstrated that viral infection can extensively modify the splicing patterns of numerous cellular transcripts. These findings provide additional insights into the complexity of virus-host interactions as these splice variants expand proteome diversity and function during viral infection. Finally, these data open new avenues of research for a better understanding of post-transcriptional events during virus infection and possible new targets toward the development of antiviral agents. Overall design: mRNAs were isolated from L929 mouse cell line, 14 hours after infection with T3D-S Reovirus or T3D-S Mutant reovirus at a MOI of 50. Control cells were uninfected. The resulting libraries were multiplexed and paired-end sequenced using Illumina HiSeq. Gene expression and alternative splicing were caracterized using Bowtie and RSEM.
Global Profiling of the Cellular Alternative RNA Splicing Landscape during Virus-Host Interactions.
Specimen part, Cell line, Subject
View SamplesRecently, attenuated Semliki Forest virus vector VA7 completely eliminated type I interferon (IFN) unresponsive human U87 glioma xenografts while IFN responsive mouse GL261 and CT-2A gliomas proved refractory to the oncolytic virotherapy. Here we describe in two clones of a well established Balb/c mouse tumor cell line, CT26 murine colon carcinoma, diametrically opposed IFN responsiveness and sensitivity to oncolytic virus. Both CT26WT and CT26LacZ clones secreted biologically active type I IFN in vitro upon infection but virus replication was self-limiting only in CT26WT cells. Total transcriptome sequencing (RNA-Seq) and western blotting experiments revealed that in sharp contrast to CT26LacZ cells, CT26WT cells had strong constitutive expression of 56 different genes associated with pattern recognition and type I interferon signaling pathways, spanning two reported anti-RNA virus gene signatures and22 genes that have been reported to have direct anti-Alphaviral activity. Correspondingly, only CT26LacZ tumors were infectable in vivo, resulting in rapid central necrosis of the tumors by 96 hours post infection and complete tumor eradication both in immunocompetent and in SCID mice. CT26LacZ tumor eradication by oncolysis induced 100% protective immunity against homologous CT26LacZ challenge but only 50% protection against heterologous CT26WT challenge, indicating LacZ immune dominance over shared antigens. We believe the two clone CT26 system described herein constitutes a challenging yet realistic model for clonally and immunologically heterogeneous cancer where a strong therapy efficacy bias toward sensitive tumor subpopulations might falsely predict therapeutic success on a broad patient scale highlighting the necessity of successful pre-screening for responsive tumors. Overall design: RNA-Seq in CT26 tumor cell line
Clonal variation in interferon response determines the outcome of oncolytic virotherapy in mouse CT26 colon carcinoma model.
No sample metadata fields
View SamplesOrganisms need to assess their nutritional state and adapt their digestive capacity to the demands for various nutrients. Modulation of digestive enzyme production represents a rational step to regulate nutriment uptake. However, the role of digestion in nutrient homeostasis has been largely neglected. In this study, we analyzed the mechanism underlying glucose repression of digestive enzymes in the adult Drosophila midgut. We demonstrate that glucose represses the expression of many carbohydrases and lipases. Our data reveal that the consumption of nutritious sugars stimulates the secretion of the transforming growth factor ß (TGF-ß) ligand, Dawdle, from the fat body. Dawdle then acts via circulation to activate TGF-ß/Activin signaling in the midgut, culminating in the repression of digestive enzymes that are highly expressed during starvation. Thus, our study not only identifies a mechanism that couples sugar sensing with digestive enzyme expression but points to an important role of TGF-ß/Activin signaling in sugar metabolism. Overall design: RNA-sequencing of whole guts from Drosophila melannogaster OregonR adult females was performed under three feeding conditions: Standard medium, glucose, and agar. Three biological repeats were performed for each condition.
Transforming growth factor β/activin signaling functions as a sugar-sensing feedback loop to regulate digestive enzyme expression.
Specimen part, Cell line, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Growth factor independence 1b (gfi1b) is important for the maturation of erythroid cells and the regulation of embryonic globin expression.
Specimen part
View SamplesGrowth factor independence 1b (Gfi1b) is a DNA binding repressor of transcription with vital functions in hematopoiesis. Gfi1b-null embryos die at midgestation very likely due to defects in erythro- and megakaryopoiesis. To analyze the full functionality of Gfi1b in embryonic erythropoiesis, we used conditionally deficient mice that harbor floxed Gfi1b alleles and one EpoR-Cre knock-in allele.
Growth factor independence 1b (gfi1b) is important for the maturation of erythroid cells and the regulation of embryonic globin expression.
Specimen part
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