Despite significant advances in our understanding of the biology determining systemic energy homeostasis, the treatment of obesity remains a medical challenge. Activation of AMP-activated protein kinase (AMPK) has been proposed as an attractive strategy for the treatment of obesity and its complications. AMPK is a conserved, ubiquitously expressed, heterotrimeric serine/threonine kinase whose short-term activation has multiple beneficial metabolic effects. Whether these translate into long-term benefits for obesity and its complications is unknown. Here, we observe that mice with chronic AMPK activation, resulting from mutation of the AMPK ?2 subunit, exhibit ghrelin signalling-dependent hyperphagia, obesity and impaired pancreatic islet insulin secretion. Humans bearing the homologous mutation manifest a congruent phenotype. Our studies highlight that long-term AMPK activation can have adverse metabolic consequences with implications for pharmacological strategies seeking to chronically activate AMPK systemically to treat metabolic disease. Overall design: Transcriptomic profiling of the hypothalamic arcuate nucleus from AMPK ?2 R299Q knock-in mice
Chronic Activation of γ2 AMPK Induces Obesity and Reduces β Cell Function.
Specimen part, Cell line, Subject
View SamplesAnalysis of adult and childhood tumors reveals activation of an E2F3 signature unique to Wilms tumors.
The E2F3-Oncomir-1 axis is activated in Wilms' tumor.
Sex, Age
View SamplesDespite the frequent detection of circulating tumor antigen-specific T cells, either spontaneously or following active immunization or adoptive transfer, immune-mediated cancer regression occurs only in the minority of patients. One theoretical rate-limiting step is whether effector T cells successfully migrate into metastatic tumor sites. Affymetrix gene expression profiling performed on a series of metastatic melanoma biopsies revealed a major segregation of samples based on the presence or absence of T cell-associated transcripts. The presence of lymphocytes correlated with the expression of defined chemokine genes. A subset of 6 chemokines (CCL2, CCL3, CCL4, CCL5, CXCL9, and CXCL10) was confirmed by protein array and/or quantitative RT-PCR to be preferentially expressed in tumors that contained T cells. Corresponding chemokine receptors were found to be upregulated on human CD8+ effector T cells, and transwell migration assays confirmed the ability of each of these chemokines to promote migration of CD8+ effector cells in vitro. Screening by chemokine protein array identified a subset of melanoma cell lines produced a similar broad array of chemokines. These melanoma cells more effectively recruited human CD8+ effector T cells when implanted as xenografts in NOD/scid mice in vivo. Chemokine blockade with specific antibodies inhibited migration of CD8+ T cells. Our results suggest that lack of critical chemokines in a subset of melanoma metastases may limit the migration of activated T cells, which in turn could limit the effectiveness of anti-tumor immunity.
Chemokine expression in melanoma metastases associated with CD8+ T-cell recruitment.
No sample metadata fields
View SamplesSummary:
HCaRG increases renal cell migration by a TGF-alpha autocrine loop mechanism.
No sample metadata fields
View SamplesHEK293 cells were transfected with control plasmid (pcDNAI/Neo;Invitrogen) or with the plasmid encoding HCaRG. Stable transfectants were synchronized and grown in the presence of 10% FBS for 48 h. Total RNAs were purified with the mini RNeasy kit (Qiagen).
HCaRG increases renal cell migration by a TGF-alpha autocrine loop mechanism.
No sample metadata fields
View SamplesTo investigate the response of Arabidopsis thaliana plants to non-freezing, cool temperatures, we subjected four week old plants to various chilling temperatures at defined times during the diurnal cycle to control for diurnal effects on transcription. From the same plants, metabolites and enzyme activities were measured as well. Interestingly a gradual change could be observed over a wide range of temperatures. Some of which could be attributed to the CBF program.
Multilevel genomic analysis of the response of transcripts, enzyme activities and metabolites in Arabidopsis rosettes to a progressive decrease of temperature in the non-freezing range.
Specimen part
View SamplesThe SCL and LMO1 oncogenic transcription factors reprogram thymocytes into self-renewing pre-leukemic stem cells (pre-LSCs). Here we report that SCL directly interacts with LMO1 to activate the transcription of a self-renewal program coordinated by LYL1.
SCL, LMO1 and Notch1 reprogram thymocytes into self-renewing cells.
Age, Specimen part
View SamplesThe Drosophila TRIM-NHL protein Brain tumor (Brat) plays important roles during early embryogenesis, in cell fate decisions, during neurogenesis and in mature neurons. Brat is an RNA-binding protein and functions as translational repressor. However, which RNAs Brat regulates and how RNA-binding specificity is achieved, is unknown. Using RNA-Immunoprecipitation we identify Brat-bound mRNAs in Drosophila embryos and define a consensus binding motif.
The Crystal Structure of the NHL Domain in Complex with RNA Reveals the Molecular Basis of Drosophila Brain-Tumor-Mediated Gene Regulation.
Specimen part
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 SamplesFoxl2 is a forkhead transcription factor expressed only in the female, but not in the male gonad. We have created mice homozygous mutant for the Foxl2 gene (KO) as well as mice carrying a conditional mutant Foxl2 allele (floxed).
Somatic sex reprogramming of adult ovaries to testes by FOXL2 ablation.
Specimen part
View Samples