Gene expression analysis identified a specific signature of differentially expressed genes discriminating TTLshort and TTLlong phenotypes.
Early relapse in ALL is identified by time to leukemia in NOD/SCID mice and is characterized by a gene signature involving survival pathways.
Specimen part
View SamplesThe most common oncogenic mutations in multiple myeloma (MM) affect N- and K-RAS leading to constitutive activation of RAS-dependent signaling. Signal transduction via RAS, Raf and MAPK has been well described as a canonical pathway. In accordance with this assumption, we showed that the activity of the MEK/ERK module is strictly dependent on pan-Raf activity. However, inhibition of MEK/ERK has no or only minor effects on MM cell survival, whereas oncogenic Ras and pan-Raf critically contribute to survival of multiple myeloma cells. Therefore, we aimed to learn more about Raf-dependent but MEK-independent signaling effectors.
Pan-Raf co-operates with PI3K-dependent signalling and critically contributes to myeloma cell survival independently of mutated RAS.
Cell line
View SamplesResveratrol is a naturally occurring compound that profoundly affects energy metabolism and mitochondrial function and serves as a calorie restriction mimetic, at least in animal models of obesity. Here we treated 10 healthy, obese men with placebo and 150 mg/day resveratrol in a randomized double-blind cross-over study for 30 days. Resveratrol supplementation significantly reduced sleeping- and resting metabolic rate. In muscle, resveratrol activated AMPK, increased SIRT1 and PGC-1alpha protein levels, increased citrate synthase activity, and improved muscle mitochondrial respiration on a fatty acid-derived substrate. Furthermore, resveratrol elevated intramyocellular lipid levels, and decreased intrahepatic lipid content, circulating glucose, triglycerides, alanine-aminotransferase, and inflammation markers. Systolic blood pressure dropped and HOMA index improved after resveratrol. In the postprandial state, adipose tissue lipolysis and plasma fatty acid and glycerol decreased. In conclusion, we demonstrate that 30 days of resveratrol supplementation induces profound metabolic changes in obese subjects, mimicking the effects of calorie restriction.
Calorie restriction-like effects of 30 days of resveratrol supplementation on energy metabolism and metabolic profile in obese humans.
Sex, Specimen part
View SamplesBackground: Exercise has a positive effect on overall health. This study was performed to get an overview of the effects of mixed exercise training on skeletal muscl
Identification of human exercise-induced myokines using secretome analysis.
Sex, Age, Race
View SamplesJoMa1 cells are pluripotent precursor cells, derived from the neural crest of mice transgenic for tamoxifen-inducible c-Myc. Following transfection with a cDNA encoding for MYCN, cells become immortlized even in the absence of tamoxifen.
MYCN and ALKF1174L are sufficient to drive neuroblastoma development from neural crest progenitor cells.
Specimen part, Cell line
View SamplesBackground: Exercising is know to have an effect on exercising skeletal muscle, but unkown is the effect on non-exercising skeletal muscle. Gene expression changes in the non-exercising skeletal muscle would point to a signalling role of skeletal muscle
Pronounced effects of acute endurance exercise on gene expression in resting and exercising human skeletal muscle.
Sex, Age, Specimen part, Race, Subject, Time
View SamplesChronic cold exposure causes white adipose tissue (WAT) to adopt features of brown adipose tissue, a process known as browning. Previous studies have hinted at a possible role for the transcription factor Peroxisome Proliferator-Activated Receptor alpha (PPAR) in cold-induced browning. Here we aimed to investigate the importance of PPAR in driving transcriptional changes during cold-induced browning in mice. Male wildtype and PPAR/ mice were housed at thermoneutrality (28 C) or cold (5 C) for 10 days. Whole genome expression analysis was performed on inguinal WAT. In addition, other analyses were carried out. Whole genome expression data of livers of wildtype and PPAR/ mice fasted for 24 h served as positive control for PPAR-dependent gene regulation.Cold exposure increased food intake and decreased weight of BAT and WAT to a similar extent in wildtype and PPAR/ mice. Except for plasma non-esterified fatty acids, none of the cold-induced changes in plasma metabolites were dependent on PPAR genotype. Histological analysis of inguinal WAT showed clear browning upon cold exposure but did not reveal any morphological differences between wildtype and PPAR/ mice. Transcriptomics analysis of inguinal WAT showed a marked effect of cold on overall gene expression, as revealed by principle component analysis and hierarchical clustering. However, wildtype and PPAR/ mice clustered together, even after cold exposure, indicating a similar overall gene expression profile in the two genotypes. Pathway analysis revealed that cold upregulated pathways involved in energy usage, oxidative phosphorylation, and fatty acid -oxidation to a similar extent in wildtype and PPAR/ mice. Furthermore, cold-mediated induction of genes related to thermogenesis such as Ucp1, Elovl3, Cox7a1, Cox8, and Cidea, as well as many PPAR target genes, was similar in wildtype and PPAR/ mice. Finally, pharmacological PPAR activation had a minimal effect on expression of cold-induced genes in murine WAT.Cold-induced changes in gene expression in inguinal WAT are unaltered in mice lacking PPAR, indicating that PPAR is dispensable for cold-induced browning.
The Peroxisome Proliferator-Activated Receptor α is dispensable for cold-induced adipose tissue browning in mice.
Sex
View SamplesType 2 diabetes is characterized by excessive lipid storage in skeletal muscle. Excessive intramyocellular lipid storage exceeds intracellular needs and induces lipotoxic events ultimately contributing to the development of insulin resistance. Lipid droplet (LD)-coating proteins may control proper lipid storage in skeletal muscle. Perilipin 2 (PLIN2/ADRP) is one of the most abundantly expressed LD-coating proteins in skeletal muscle. Here we examined the role of PLIN2 in myocellular lipid handling and insulin sensitivity by investigating the effects of in vitro PLIN2 knockdown and in vitro and in vivo overexpression. PLIN2 knockdown decreased LD formation and triacylglycerol storage, marginally increased FA oxidation, and increased incorporation of palmitate into diacylglycerols and phospholipids. PLIN2 overexpression in vitro increased intramyocellular TAG storage paralleled with improved insulin sensitivity. In vivo muscle-specific PLIN2 overexpression resulted in increased LD accumulation and blunted the high-fat diet-induced increase of OXPHOS protein content. Diacylglycerol levels were unchanged, while ceramide levels were increased. Despite the increased intramyocellular lipid accumulation, PLIN2 overexpression improved skeletal muscle insulin sensitivity. We conclude that PLIN2 is essential for lipid storage in skeletal muscle by enhancing the partitioning of excess FAs towards triacylglycerol storage in LDs thereby blunting lipotoxicity-associated insulin resistance.
Perilipin 2 improves insulin sensitivity in skeletal muscle despite elevated intramuscular lipid levels.
Cell line
View SamplesAims/hypothesis: While lipid deposition in skeletal muscle is considered to be involved in obesity-associated insulin resistance, neutral intramyocellular lipid (IMCL) accumulation per se does not necessarily induce insulin resistance. We previously demonstrated that overexpression of the lipid droplet coat protein perilipin 2 augments intramyocellular lipid content while improving insulin sensitivity. Another member of the perilipin family, perilipin 5 (PLIN5), is predominantly expressed in oxidative tissues like skeletal muscle. Here we investigated the effects of PLIN5 overexpression in comparison with effects of PLIN2 on skeletal muscle lipid levels, gene expression profiles and insulin sensitivity. Methods: Gene electroporation was used to overexpress PLIN5 in tibialis anterior muscle of rats fed a high fat diet. Eight days after electroporation, insulin-mediated glucose uptake in skeletal muscle was measured by means of a hyperinsulinemic euglycemic clamp. Electron microscopy, fluorescence microscopy and lipid extractions were performed to investigate IMCL accumulation. Gene expression profiles were obtained using microarrays. Results: TAG storage and lipid droplet size increased upon PLIN5 overexpression. Despite the higher IMCL content, insulin sensitivity was not impaired and DAG and acylcarnitine levels were unaffected. In contrast to the effects of PLIN2 overexpression, microarray data analysis revealed a gene expression profile favoring FA oxidation and improved mitochondrial function. Conclusions/interpretation: Both PLIN2 and PLIN5 increase neutral IMCL content without impeding insulin-mediated glucose uptake. As opposed to the effects of PLIN2 overexpression, overexpression of PLIN5 in skeletal muscle promoted expression of a cluster of genes under control of PPAR and PGC1 involved in FA catabolism and mitochondrial oxidation.
Overexpression of PLIN5 in skeletal muscle promotes oxidative gene expression and intramyocellular lipid content without compromising insulin sensitivity.
Sex, Age, Specimen part, Treatment
View SamplesThe right ventricle (RV) differs in several aspects from the left ventricle (LV) including its embryonic origin, physiological role and anatomical design. In contrast to LV hypertrophy, little is known about the molecular circuits, which are activated upon RV hypertrophy (RVH). We established a highly reproducible model of RVH in mice using pulmonary artery clipping (PAC), which avoids detrimental RV pressure overload and thus allows long-term survival of operated mice. Magnetic resonance imaging revealed pathognomonic changes with striking similarities to human congenital heart disease- or pulmonary arterial hypertension- patients. Comparative, microarray based transcriptome analysis of right- and left-ventricular remodeling identified distinct transcriptional responses to pressure-induced hypertrophy of either ventricle, which were mainly characterized by stronger transcriptional responses of the RV compared to the LV myocardium. Hierarchic cluster analysis revealed a RV- and LV-specific pattern of gene activity after induction of hypertrophy, however, we did not find evidence for qualitatively distinct regulatory pathways in RV compared to LV. Data mining of nearly three thousand RV-enriched genes under PAC disclosed novel potential (co)-regulators of long-term RV remodeling and hypertrophy. We reason that specific inhibitory mechanisms in RV restrict excessive myocardial hypertrophy and thereby contribute to its vulnerability to pressure overload.
Identification of right heart-enriched genes in a murine model of chronic outflow tract obstruction.
Sex, Age, Specimen part
View Samples