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GSE17841
Mus musculus
18 Downloadable Samples
Affymetrix Mouse Gene 1.0 ST Array (mogene10st)
Description
Background and aims: The transcription factor Stat3 has been considered to promote progression and metastasis of intestinal cancers.
Publication Title
Stat3 is a negative regulator of intestinal tumor progression in Apc(Min) mice.
Sample Metadata Fields
Sex, Specimen part
View Samples- Mus musculus
- 8 Downloadable Samples
- Affymetrix Mouse Gene 2.1 ST Array (mogene21st)
Description
In the intestine, Hedgehog (Hh) signalling orchestrates epithelial homeostasis in a bidirectional loop. Differentiated enterocytes secrete the ligand leading to active downstream signaling exclusively in the stroma. In turn, Hh-driven stromal factors contribute to the control of intestinal stem cell numbers and induce epithelial differentiation.
Publication Title
Stromal Hedgehog signalling is downregulated in colon cancer and its restoration restrains tumour growth.
Sample Metadata Fields
Sex, Specimen part
View Samples- Mus musculus
- 12 Downloadable Samples
- Affymetrix Mouse Gene 1.0 ST Array (mogene10st)
Description
Background and aims: Signal transducer and activator of transcription 3 (Stat3) is the main mediator of interleukin-6 type cytokine signaling required for hepatocyte proliferation and hepatoprotection but its role in sclerosing cholangitis (SC) and other cholestatic liver diseases remains unresolved. Methods: We investigated the role of Stat3 in inflammation-induced cholestatic liver injury and used mice lacking the multidrug resistance gene 2 (mdr2-/-) as a model for SC. Results: We demonstrate that conditional inactivation of stat3 in hepatocytes and cholangiocytes (stat3hc) of mdr2-/- mice strongly aggravated bile acid-induced liver injury and fibrosis. Similarly, stat3hc mice are more sensitive to cholic acid feeding than control mice. Global gene expression analysis demonstrated that hepatoprotective signals via epidermal growth factor and insulin-like growth factor 1 are affected upon loss of Stat3. Conclusions: Our data suggest that Stat3 protects cholangiocytes and hepatocytes from bile acid-induced damage thereby preventing liver fibrosis in cholestatic diseases.
Publication Title
Signal transducer and activator of transcription 3 protects from liver injury and fibrosis in a mouse model of sclerosing cholangitis.
Sample Metadata Fields
Age, Specimen part
View Samples- Mus musculus
- 4 Downloadable Samples
Illumina HiSeq 4000
Description
Lgr6-positive cells have been shown to label stem/progenitors cells in several tissues including tongue and skin. However their role in mammary gland has never been investigated. Here we used Lgr6-eGFP-IRES-CreER2 mice to isolate and characterize Lgr6-positive population in mammary gland of 5-week old female mice. Overall design: Examination of transcriptional differences between Lgr6 positive and negative cells
Publication Title
Lgr6 labels a rare population of mammary gland progenitor cells that are able to originate luminal mammary tumours.
Sample Metadata Fields
Sex, Specimen part, Subject
View Samples- Mus musculus
- 3 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Loss of muscle mass occurs in a variety of diseases including cancer, chronic heart failure, AIDS, diabetes and renal failure, often aggravating pathological progression. Preventing muscle wasting by promoting muscle growth has been proposed as a possible therapeutic approach. Myostatin is an important negative modulator of muscle growth during myogenesis and myostatin inhibitors are attractive drug targets. However, the role of the myostatin pathway in adulthood and the transcription factors involved in the signaling are unclear. Moreover recent results confirm that other TGF members control muscle mass. Using genetic tools we perturbed this pathway in adult myofibers, in vivo, to characterize the downstream targets and their ability to control muscle mass. Smad2 and Smad3 are the transcription factors downstream of myostatin/TGF and induce an atrophy program which is MuRF1 independent and requires FoxO activity. Furthermore Smad2/3 inhibition promotes muscle hypertrophy independent of satellite cells but partially dependent of mTOR signalling. Thus myostatin and Akt pathways cross-talk at different levels. These findings point to myostatin inhibitors as good drugs to promote muscle growth during rehabilitation especially when they are combined with IGF1-Akt activators.
Publication Title
Smad2 and 3 transcription factors control muscle mass in adulthood.
Sample Metadata Fields
Specimen part, Time
View Samples- Homo sapiens
- 56 Downloadable Samples
- Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
Dietary fat quality may influence skeletal muscle lipid handling and fat accumulation, thereby modulating insulin sensitivity. Objective: To examine acute effects of meals with various fatty acid (FA) compositions on skeletal muscle FA handling and postprandial insulin sensitivity in obese insulin resistant men. Design: In a single-blinded randomized crossover study, 10 insulin resistant men consumed three high-fat mixed-meals (2.6MJ). Meals were high in saturated FA (SFA), in monounsaturated FA (MUFA) or in polyunsaturated FA (PUFA). Fasting and postprandial skeletal muscle FA handling were examined by measuring arterio-venous concentration differences across forearm muscle. [2H2]-palmitate was infused intravenously to label endogenous triacylglycerol (TAG) and FFA in the circulation and [U-13C]-palmitate was added to the meal to label chylomicron-TAG. Skeletal muscle biopsies were taken to assess intramuscular lipid metabolism and gene expression. Results: Insulin and glucose responses (AUC) after SFA meal were significantly higher compared with PUFA meal (p=0.003 and 0.028, respectively). Uptake of TAG-derived FA was significantly lower in the early postprandial phase after PUFA meal as compared with other meals (AUC60-120, p<0.001). The PUFA meal induced less transcriptional downregulation of oxidative pathways compared with other meals. The fractional synthetic rate was higher in DAG and PL fraction after MUFA and PUFA meal. Conclusion: Intake of a PUFA meal reduced TAG-derived skeletal muscle FA uptake, which was accompanied by higher postprandial insulin sensitivity and a tendency towards a higher muscle lipid turnover. These data suggest that the effects of replacement of SFA by PUFA may contribute to less muscle lipid uptake and may be therefore protective against the development of insulin resistance.
Publication Title
PUFAs acutely affect triacylglycerol-derived skeletal muscle fatty acid uptake and increase postprandial insulin sensitivity.
Sample Metadata Fields
Sex, Age, Time
View Samples- Homo sapiens
- 18 Downloadable Samples
- Affymetrix Human Gene 1.1 ST Array (hugene11st)
Description
Polyphenolic compounds, such as resveratrol, have recently received widespread interest due to their ability to mimic effects of calorie restriction. The objective of the present study was to gain more insight into the effects of 30 days resveratrol supplementation on adipose tissue morphology and underlying processes. Nine healthy obese men were supplemented with placebo and 150mg/day resveratrol for 30 days, separated by a 4-week washout period. A postprandial abdominal subcutaneous adipose tissue biopsy was collected to assess adipose tissue morphology and gene expression using microarray analysis. Resveratrol significantly decreased adipocyte size, with a shift towards a reduction in the proportion of large and very large adipocytes and an increase in small adipocytes. Microarray analysis revealed downregulation of Wnt, Notch and BMP/TGF- signaling pathways and upregulation of pathways involved in cell cycle after resveratrol supplementation, suggesting enhanced adipogenesis. Furthermore, the lysosomal/phagosomal pathway and the transcription factor EB were upregulated, reflecting an alternative pathway of lipid breakdown by autophagy. These data suggest that adipose tissue is an important target tissue for the effects of resveratrol in humans, but further research is necessary to investigate whether it translates into an improved adipose tissue function.
Publication Title
The effects of 30 days resveratrol supplementation on adipose tissue morphology and gene expression patterns in obese men.
Sample Metadata Fields
Sex, Age, Specimen part, Disease, Treatment, Race, Subject
View Samples- Homo sapiens
- 52 Downloadable Samples
- Affymetrix Human Transcriptome Array 2.0 (hta20)
Description
The obese, insulin resistant state is characterized by impairments in lipid metabolism. Dietary polyphenols might improve these deteriorations. We have previously shown that 3-days supplementation of combined Epigallocatechin-gallate and Resveratrol (E+R) increased energy expenditure, which was accompanied by improved metabolic flexibility after a high-fat mixed-meal (HFMM) in men. The present study aimed to investigate whether these short-term effects translate into longer-term improvement of insulin sensitivity and lipid metabolism. In this randomized, double-blind study, 42 overweight subjects (21 male, 382 yrs, BMI 29.70.5 kg/m2, HOMA-IR 2.10.2) received either E+R (300 and 80 mg/d, respectively) or placebo (PLA) for 12 weeks (3 months). Before (t0) and after (t3) intervention, tissue-specific insulin sensitivity was assessed by a hyperinsulinemic-euglycemic clamp with stable isotope infusion. Fasting and postprandial (HFMM) lipid metabolism was assessed using indirect calorimetry and blood sampling. Adipose tissue and skeletal muscle lipolysis was measured using microdialysis in men and skeletal muscle biopsies were collected to assess mitochondrial function and gene expression alterations via microarray analysis. E+R supplementation increased fasting (P=0.06) and postprandial (P=0.03) fat oxidation but did not alter energy expenditure compared to PLA. This was accompanied by an E+R-induced increase in oxidative capacity in permeabilized muscle fibers (p<0.05). Moreover, E+R supplementation attenuated the increase in plasma triacylglycerol concentration that was observed in the PLA group (AUC, p<0.05), and tended to decrease visceral fat mass (P=0.09). Finally, insulin-stimulated glucose disposal and suppression of endogenous glucose production were not affected by E+R supplementation. 12 weeks E+R supplementation increased whole-body fat oxidation and skeletal muscle oxidative capacity, but this did not translate into increased tissue-specific insulin sensitivity in overweight and obese subjects.
Publication Title
Combined epigallocatechin-3-gallate and resveratrol supplementation for 12 wk increases mitochondrial capacity and fat oxidation, but not insulin sensitivity, in obese humans: a randomized controlled trial.
Sample Metadata Fields
Sex, Age, Specimen part, Treatment, Time
View Samples- Mus musculus
- 4 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Under stress conditions mammalian cells activate compensatory mechanisms to survive and maintain cellular function. During catabolic conditions, such as low nutrients, systemic inflammation, cancer or infections, protein breakdown is enhanced and aminoacids are released from muscles to sustain liver gluconeogenesis and tissues protein synthesis. Proteolysis in muscle is orchestrated by a set of genes named atrophy-related genes. A system that is activated both in short and prolonged stress conditions is the family of Forkhead Box (Fox) O transcription factors. Here, we report that muscle-specific deletion of FoxO members resulted in protection from muscle loss because FoxO family is required for induction of autophagy-lysosome and ubiquitin-proteasome systems. Importantly, FoxOs are required for Akt activity but not for mTOR signalling underlining the concept that FoxOs are upstream mTOR for the control of protein breakdown when nutrients are lacking. Moreover, FoxO family controls the induction of critical genes belonging to several fundamental stress response pathways such as unfolded protein response, ROS detoxification and translational regulation. Finally, we identify a set of novel FoxO-dependent ubiquitin ligases including the recent discovered MUSA11 and a new one, which we named Specific of Muscle Atrophy and Regulated by Transcription (SMART). Our findings identify the critical role of FoxO in regulating a variety of genes belonging to pathways important for stress-response under catabolic conditions.
Publication Title
Regulation of autophagy and the ubiquitin-proteasome system by the FoxO transcriptional network during muscle atrophy.
Sample Metadata Fields
Sex
View Samples- Rattus norvegicus
- 12 Downloadable Samples
- Affymetrix Rat Genome 230 2.0 Array (rat2302)
Description
The myogenic regulatory factor MRF4 is expressed at high levels in myofibers of adult skeletal muscle, but its function is unknown. Here we show that knockdown of MRF4 in adult muscle causes hypertrophy and prevents denervation-induced atrophy. This effect is accompanied by increased protein synthesis and the widespread activation of genes involved in muscle contraction, excitation-contraction coupling and energy metabolism, many of which are known targets of MEF2 transcription factors. Genes regulated by MEF2 represent the top-ranking gene set enriched after Mrf4 RNAi, and a MEF2 reporter is inhibited by co-transfected MRF4 and activated by Mrf4 RNAi. The role of MEF2 in mediating the effect of MRF4 knockdown is supported by the finding that Mrf4 RNAi-dependent increase in fiber size is prevented by dominant negative MEF2, while constitutively active MEF2 is able to induce myofiber hypertrophy. The nuclear localization of the MEF2 co-repressor HDAC4 is impaired by Mrf4 knockdown, suggesting that MRF4 acts by stabilizing a repressor complex that controls MEF2 activity. The demonstration that fiber size in adult skeletal muscle is controlled by the MRF4-MEF2 axis opens new perspectives in the search for therapeutic targets to prevent muscle wasting, in particular sarcopenia and cachexia.
Publication Title
MRF4 negatively regulates adult skeletal muscle growth by repressing MEF2 activity.
Sample Metadata Fields
Specimen part
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