Analysis of hematopoietic stem cells (HSC, LSK Flt3-) and myeloid progenitors (MP, LK CD34+) sorted from wildtype and Dnmt1 hypomorph mice
DNA methylation protects hematopoietic stem cell multipotency from myeloerythroid restriction.
Specimen part
View SamplesThe endocytic receptor megalin constitutes the main pathway for clearance of plasma proteins from the glomerular filtrate in the proximal tubules. However, little is know about the mechanisms that control receptor activity. A widely discussed hypothesis states that the intracellular domain (ICD) of megalin, released upon ligand binding, acts as a transcription regulator to suppress receptor expression - a mechanism proposed to safeguard the proximal tubules from protein overload. Here, we have put this hypothesis to the test by generating a mouse model co-expressing the soluble ICD and the full-length receptor. Despite pronounced expression in the proximal tubules, the ICD failed to exert any effects on renal proximal tubular function such as megalin expression, protein retrieval, or renal gene transcription. Thus, our data argue that the ICD does not play a role in regulation of megalin activity in vivo in the proximal tubules.
The soluble intracellular domain of megalin does not affect renal proximal tubular function in vivo.
Sex, Age, Specimen part
View SamplesWe aimed to define epithelial-specific genes in the kidney. In the developing mouse kidney at E12.5 epithelial cells are restricted to the ureteric bud, while mesenchymal cells surrounding the ureteric bud are non-epithelial. The mouse renal epithelial cell line mIMCD-3 was used to represent kidney epithelia in vitro. Gene expression was analyzed using Affymetrix microarrays in ureteric bud stalks, ureteric bud tips, and mIMCD-3 cells and compared to metanephric mesenchyme.
The transcription factor grainyhead-like 2 regulates the molecular composition of the epithelial apical junctional complex.
Specimen part, Cell line
View SamplesAims: We investigate sex differences and the role of oestrogen receptor beta (ERbeta) in a mouse model of pressure overload-induced myocardial hypertrophy. Methods and results: We performed transverse aortic constriction (TAC) or sham surgery in male and female wild-type (WT) and ERbeta knockout (ERbeta-/-) C57Bl6 mice. All mice were characterised by echocardiography and haemodynamic measurements and were sacrificed nine weeks after surgery. Left ventricular (LV) samples were analysed by microarray profiling, real-time RT-PCR and histology. After nine weeks, WT males showed more hypertrophy and heart failure signs than WT females. Notably, WT females developed a concentric form of hypertrophy, while males developed eccentric hypertrophy. These sex differences were abolished in ERbeta-/- mice. ERbeta deletion augmented the TAC-induced increase in cardiomyocyte diameter in both sexes. Gene expression profiling revealed that male WT hearts had a stronger induction of matrix-related genes and a stronger repression of mitochondrial genes than female hearts. ERbeta-/- mice exhibited a different transcriptome. Induction of pro-apoptotic genes after TAC occurred in ERbeta-/- mice of both sexes with a stronger expression in ERbeta-/- males. Histological analysis revealed, that cardiac fibrosis was more pronounced in male WT TAC than in female mice. This was abolished in ERbeta-/- mice. Apoptosis was significantly induced in both sexes of ERbeta-/- TAC mice, but it was most prominent in males. Conclusion: Female sex offers protection against ventricular chamber dilation in the TAC model. Both the female sex and ERbeta attenuate the development of fibrosis and apoptosis; thus slowing the progression to heart failure.
Female sex and estrogen receptor-beta attenuate cardiac remodeling and apoptosis in pressure overload.
Sex, Age, Specimen part
View SamplesMechanisms controlling the proliferative activity of neural stem/progenitor cells (NSPCs) play a pivotal role to ensure life-long neurogenesis in the mammalian brain. How metabolic programs are coupled with NSPC activity remains unknown. Here we show that fatty acid synthase (FASN), the key enzyme of de novo lipogenesis, is highly active in adult NSPCs and that conditional deletion of FASN in NSPCs impairs adult neurogenesis. The rate of de novo lipid synthesis and subsequent proliferation of NSPCs is regulated by Spot14, a gene we found to be selectively expressed in low proliferating adult NSPCs. Spot14 reduces the availability of malonyl-CoA, which is an essential substrate for FASN to fuel lipogenesis. Thus, we here identified a functional coupling between the regulation of lipid metabolism and adult NSPC proliferation.
No associated publication
Specimen part
View SamplesIn order to identify the genes regulated in mouse embryonic stem cells (mESC) by the effect of low concentrations of nitric oxide (NO), we analysed the transcriptome of cells treated with NO and compared it to those of cells cultured in the absence of leukemia inhibitory factor (LIF), and in the presence of LIF. We used the cell line D3-pOct4, which carries the enhanced Green Fluorescence Protein gene (eGFP) under the control of the Oct-4 promotor. This line is continuously maintained in the undifferentiated state in the presence of LIF, in comparison with the wild type line .
No associated publication
No sample metadata fields
View SamplesIn order to study the consequences of the loss of Icsbp expression in hematopoiesis Granulocyte-Monocyte Progenitors from bone marrow were isolated from Icsbp wild type and deficient mice by flow cytometry. Global gene expression was performed using Affymetrix gene chip technology.
No associated publication
No sample metadata fields
View SamplesBeyond the DNA sequence difference between humans and closely related apes, there are large differences in the environments that these species experience. One prominent example for this is diet. The human diet diverges from those of other primates in various aspects, such as having a high calorie and protein content, as well as being cooked. Here, we used a laboratory mouse model to identify gene expression differences related to dietary differences.
Human and chimpanzee gene expression differences replicated in mice fed different diets.
Sex, Age
View SamplesIn development, timing is of the utmost importance, and the timing of various developmental processes are often changed during evolution.
Transcriptional neoteny in the human brain.
Sex, Age, Specimen part
View SamplesLoss 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.
Smad2 and 3 transcription factors control muscle mass in adulthood.
Specimen part, Time
View Samples