Both cigarette smoking and obesity have been implicated in increased risk of clear cell renal cell carcinoma (ccRCC); however, there are limited data regarding the molecular mechanisms that underlie these associations. We used a multi-stage design to identify and validate specific molecular targets that are associated with smoking or obesity-related ccRCC.
ANKS1B is a smoking-related molecular alteration in clear cell renal cell carcinoma.
Specimen part, Subject
View SamplesThe liver circadian clock is reprogrammed by nutritional challenge through the rewiring of specific transcriptional pathways. As the gut microbiota is tightly connected to host metabolism, whose coordination is governed by the circadian clock, we explored whether gut microbes influence circadian homeostasis and how they distally control the peripheral clock in the liver. Using fecal transplant procedures we reveal that, in response to high fat diet, the gut microbiota drives PPAR-mediated activation of newly oscillatory transcriptional programs in the liver. Moreover, antibiotics treatment prevents PPAR-driven transcription in the liver, underscoring the essential role of gut microbes in clock reprogramming and hepatic circadian homeostasis. Thus, a specific molecular signature characterizes the influence of the gut microbiome in the liver, leading to the transcriptional rewiring of hepatic metabolism.
Gut microbiota directs PPARγ-driven reprogramming of the liver circadian clock by nutritional challenge.
Specimen part
View SamplesThe circadian clock orchestrates rhythms in physiology and behavior, allowing the organism to adapt to daily environmental changes. Recently, efforts have been made to unravel the connection between the circadian clock and metabolism and to understand how the peripheral clock in different organs coordinates circadian responses to maintain metabolic homeostasis. It is becoming clear that diet can influence diurnal rhythms, however, the molecular mechanisms responsible for alterations in daily oscillations and how tissue-specific clocks interpret a nutritional challenge are not well understood. Here, we reveal tissue-specific circadian plasticity in response to a ketogenic diet (KD) in both the liver and intestine and a remarkable deviation within these two tissues following subsequent carbohydrate supplementation. KD caused a dramatic change in the circadian transcriptome in both liver and intestine in a tissue-specific fashion. In particular, both the amplitude of clock genes as well as specific BMAL1 recruitment was profoundly altered by KD while the intestinal clock was devoid of such plasticity. While PPARG nuclear accumulation was circadian in both tissues, it showed substantial phase specificity as did downstream targets. Finally, the gut and liver clocks had distinct responses to carbohydrate supplementation to KD composition, suggesting a higher plasticity in the ileum whose gene expression was almost restored to control baseline. For the first time our results demonstrate how nutrients modulate clock function in a tissue-specific manner, suggesting that a food stress arouses unique circadian molecular signatures in distinct peripheral tissues.
Distinct Circadian Signatures in Liver and Gut Clocks Revealed by Ketogenic Diet.
Specimen part
View SamplesA complex interplay between ethylene, ETP1/ETP2 F-box proteins, and degradation of EIN2 is essential for triggering ethylene responses in plants.
Interplay between ethylene, ETP1/ETP2 F-box proteins, and degradation of EIN2 triggers ethylene responses in Arabidopsis.
Age, Treatment
View SamplesEvaluation of differential expression between CLL patients in a chemoimmunotherapy trial with age-matched controls
LEF-1 is a prosurvival factor in chronic lymphocytic leukemia and is expressed in the preleukemic state of monoclonal B-cell lymphocytosis.
Specimen part, Disease, Disease stage
View SamplesThe Skeletal muscle is a metabolic active tissue that secretes various proteins. These so called myokines act auto-, para- and endocrine affecting muscle physiology and exert systemic effects on other tissues and organs. Myokines are also described to play a crucial role in the pathophysiology of metabolic diseases.
Secretome profiling of primary human skeletal muscle cells.
Sex, Specimen part, Subject
View SamplesCircadian and metabolic processes are codependent. This experiment was designed to understand how a high fat diet affects circadian gene expression in the liver. Circadian gene expression in the liver is necessary for energy balance.
Reprogramming of the circadian clock by nutritional challenge.
Specimen part
View SamplesChronic low dose inorganic arsenic (iAs) exposure leads to changes in gene expression and epithelial-to-mesenchymal transformation. During this transformation, cells adopt a fibroblast-like phenotype accompanied by profound gene expression changes. While many mechanisms have been implicated in this transformation, studies that focus on the role of epigenetic alterations in this process are just emerging. DNA methylation controls gene expression in physiologic and pathologic states. Several studies show alterations in DNA methylation patterns in iAs-mediated pathogenesis, but these studies focused on single genes. We present a comprehensive genome-wide DNA methylation analysis using methyl-sequencing to measure changes between normal and iAs-transformed cells. Additionally, these differential methylation changes correlated positively with changes in gene expression and alternative splicing. Interestingly, most of these differentially methylated genes function in cell adhesion and communication pathways. To gain insight into how genomic DNA methylation patterns are regulated iAs-mediated carcinogenesis, we show that iAs probably targets CTCF binding at the promoter of DNA methyltransferases, regulating their expression. These findings reveal how transcription factor binding regulates DNA methyltransferase to reprogram the methylome in response to an environmental toxin.
Genome-wide DNA methylation reprogramming in response to inorganic arsenic links inhibition of CTCF binding, DNMT expression and cellular transformation.
Specimen part, Cell line, Treatment
View SamplesIt is unknown if gene expression profiles from primary RCC tumors differ from patient-matched metastatic tumors. Thus, we sought to identify differentially expressed genes between patient-matched primary and metastatic RCC tumors in order to understand the molecular mechanisms underlying the development of RCC metastases.
Differential gene expression profiling of matched primary renal cell carcinoma and metastases reveals upregulation of extracellular matrix genes.
Specimen part, Subject
View SamplesThe molecular regulation of zygotic genome activation (ZGA) in mammals remains poorly understood. Primed mouse embryonic stem cells contain a rare subset of “2C-like” cells that are epigenetically and transcriptionally similar to the two cell embryo and thus represent an ideal system for studying ZGA transcription regulation. Recently, the transcription factor Dux, expressed exclusively in the minor wave of ZGA, was described to activate many downstream ZGA transcripts. However, it remains unknown what upstream maternal factors initiate ZGA either in a Dux dependent or independent manner. Here we performed a candidate-based overexpression screen, identifying, amongst others, Developmental Pluripotency Associated 2 (Dppa2) and 4 (Dppa4) as positive regulators of 2C-like cells and ZGA transcription. In the germ line, promoter DNA demethylation coincides with upregulation of Dppa2 and Dppa4 which remain expressed until E7.5 when their promoters are remethylated. Furthermore, Dppa2 and Dppa4 are also expressed during iPSC reprogramming at the time 2C-like ZGA transcription transiently peaks. Through a combination of overexpression, knockdown, knockout and rescue experiments, together with transcriptional analyses, we show that Dppa2 and Dppa4 directly regulate the 2C-like cell population and associated transcripts, including Dux and the Zscan4 cluster. Importantly, we tease apart the molecular hierarchy in which the 2C-like transcriptional program is initiated and stabilised. Dppa2 and Dppa4 require Dux to initiate 2C-like ZGA transcription, suggesting they act upstream by directly regulating Dux. Supporting this, ChIP-seq analysis revealed Dppa2 and Dppa4 bind to the Dux promoter and gene body and drive its expression. Zscan4c is also able to induce 2C-like cells in wild type cells, but, in contrast to Dux, can no longer do so in Dppa2/4 double knockout cells, suggesting it may act to stabilise rather than drive the transcriptional network. Our findings suggest a model in which Dppa2/4 binding to the Dux promoter leads to Dux upregulation and activation of the 2C-like transcriptional program which is subsequently reinforced by Zscan4c. Overall design: RNA sequencing of screen hits (3 biological replicates of GFP+ and GFP- sorted cells for each of 12 candidates).
Dppa2 and Dppa4 directly regulate the Dux-driven zygotic transcriptional program.
Specimen part, Cell line, Subject
View Samples