Major causes of lipid accumulation in liver are increased import, synthesis or decreased catabolism of fatty acids. The latter is caused by dysfunction of cellular organelle controlling energy homeostasis, i.e. mitochondria. However, peroxisomes appear to be an important organelle in lipid metabolism of hepatocytes, but little is known about their role in the development of non-alcoholic fatty liver disease (NAFLD). To investigate the role of peroxisomes next to mitochondria in excessive hepatic lipid accumulation we used the leptin resistant db/db mice on C57BLKS background, a mouse model that develops hyperphagia induced diabetes with obesity and NAFLD.
Peroxisomes compensate hepatic lipid overflow in mice with fatty liver.
Sex, Age, Specimen part
View SamplesPurpose: MetS consist of five risk factors: elevated blood pressure and fasting glucose, visceral obesity, dyslipidemia and hypercholesterinemia. The physiological impact of lipid metabolism indicated as visceral obesity and hepatic lipid accumulation is still under debate. One major cause of disturbed lipid metabolism might be dysfunction of cellular organelles controlling energy homeostasis, i.e. mitochondria and peroxisomes.
Alteration of Liver Peroxisomal and Mitochondrial Functionality in the NZO Mouse Model of Metabolic Syndrome.
Sex, Age, Specimen part
View SamplesLipodystrophies resemble syndromes of disturbed adipocyte biology or development and severe congenital forms (CGL) lack adipose tissue. The ubiquitous immediate-early gene c-fos is one essential transcription factor to initiate adipocyte differentiation. In a CGL patient we identified a single homozygous point mutation in the promoter of c-fos gene. The mutation facilitates the formation of a novel specific protein/ DNA complex and ubiquitously reduces basal and inducible c-fos transcription activity.
A mutation in the c-fos gene associated with congenital generalized lipodystrophy.
No sample metadata fields
View SamplesEmbryonic stem cells (ESCs) cells run a self-renewal gene expression program, requiring the expression of certain transcription factors accompanied by a particular chromosome organization to maintain a balance between pluripotency and the capacity for rapid differentiation. However, how transcriptional regulation is linked to chromosome organization in ESCs remains enigmatic. Here we show that Cohesin exhibits a functional role in maintaining ESC identity through association with the pluripotency transcriptional network. ChIP-seq analyses of the cohesin subunit Rad21 reveal an ESC specific cohesin binding pattern that is characterized by a CTCF independent colocalization of cohesin with pluripotency related transcription factors. Upon ESC differentiation, these binding sites disappear and instead new CTCF independent Rad21 binding sites emerge, which are enriched for binding sites of transcription factors implicated in early differentiation. Furthermore, knock-down of cohesin subunits causes expression changes that are reminiscent of the depletion of key pluripotency transcription factors, demonstrating the functional relevance of the cohesin - pluripotency transcriptional network association. Finally, we show that Nanog physically interacts with the cohesin interacting proteins Stag1 and Wapl, further substantiating this association. Based on these findings we propose that a dynamic placement of cohesin by pluripotency transcription factors contributes to a chromosome organization supporting the ESC expression program.
RAD21 cooperates with pluripotency transcription factors in the maintenance of embryonic stem cell identity.
Specimen part
View SamplesLong non-coding RNAs (lncRNAs) regulate diverse biological pathways. Unlike protein coding genes, where methods to comprehensibly study their functional roles in cellular systems are available, techniques to systematically investigate lncRNAs have largely remained unexplored. Here, we report a technology for combined Knockdown and Localization Analysis of Non-coding RNAs (c-KLAN) that merges phenotypic characterization and localization approaches to study lncRNAs. Using a library of endoribonuclease prepared short interfering RNAs (esiRNAs) coupled with a pipeline for synthesizing labeled riboprobes for RNA fluorescence in situ hybridization (FISH), we demonstrate the utility of c-KLAN by identifying a novel transcript Panct1 (Pluripotency associated non-coding transcript 1) that regulates embryonic stem cell identity. We postulate that c-KLAN should be generally useful in the discovery of lncRNAs implicated in various biological processes.
Combined RNAi and localization for functionally dissecting long noncoding RNAs.
Specimen part
View SamplesIn order to define the transcriptional network functionally regulated by Pax8 as well as infer its direct targets, we performed RNAi to knock-down Pax8 gene in FRTL-5 thyroid cells. Expression data from three independent silencing experiments were analyzed by microarray technology unraveling 2815 genes differentially expressed between silenced cells and controls. Of these, 1421 genes were down-regulated and 1394 genes were up-regulated 72hrs after Pax8 silencing.
Identification of novel Pax8 targets in FRTL-5 thyroid cells by gene silencing and expression microarray analysis.
Cell line
View SamplesIn contrast to the migration of leukocytes from blood vessels into tissues, and the involvement of adhesion molecules and chemokines in this process, the migration of leukocytes from the tissue into lymphatic vessels is much less well understood. This can, in part be explained by the fact that murine lymphatic endothelial cells (LECs) have proven particularly hard to isolate and propagate in culture. Hence, it has been difficult to establish suitable models to study this process in vitro. Combining magnetic bead-based purification and fluorescence-activated cell sorting (FACS), we have isolated LECs (immorto-LECs) from the skin of mice which express a temperature-sensitive SV40 large T antigen (H-2Kb-tsA58 mice; ImmortoMice) in all cell types under the control of the MHC-class-I-promotor, H-2Kb. The isolated cells are viable for more than 30 passages when cultured at 33 C, the temperature at which the large T antigen is stably expressed. Furthermore, immorto-LECs tolerate several days of culture at 37 C, but become senescent if continuously cultured at this temperature. All cells stably express endothelial and lymphatic markers like CD31, podoplanin, Prox-1 and VEGFR-3 up to passage 30. When cultured in presence of tumor necrosis factor-alpha (TNF-a), immorto-LECs upregulate adhesion molecules, such as ICAM-1, VCAM-1 and E-selectin, similarly to what has been reported to occur under inflammatory conditions in vivo. Overall, our findings establish immorto-LECs as a useful and handy tool for the in vitro investigation of immune cell transmigration across lymphatic endothelium.
Tissue inflammation modulates gene expression of lymphatic endothelial cells and dendritic cell migration in a stimulus-dependent manner.
Specimen part
View SamplesTo monitor global transcript changes after Paf1C depletion we transfected ESCs with esiRNA targeting Ctr9 and control esiRNA (Luc).
A genome-scale RNAi screen for Oct4 modulators defines a role of the Paf1 complex for embryonic stem cell identity.
No sample metadata fields
View SamplesThe AIL transcription factor BABY BOOM (BBM) is required together with the related PLETHORA proteins for embryo and root meristem development and its expression is sufficient to confer pluripotency and totipotency to somatic tissues. We show that BBM and other AIL proteins interact with multiple members of the L1/epidermal-expressed HD-ZIP class IV / HOMEODOMAIN GLABROUS (HDG) transcription factor family. Ectopic overexpression of HDG1, HDG11 and HDG12 genes induces a reduced growth phenotype, and analysis of HDG1 overexpression lines shows that this growth reduction is due to both root and shoot meristem arrest. To understand how HDG1 controls cell proliferation, as well as its functional relationship with BBM, we performed microarray experiments to identify candidate genes that are directly regulated by HDG1, and compared these to the set of genes that are directly regulated by BBM expression.
AIL and HDG proteins act antagonistically to control cell proliferation.
Specimen part, Treatment
View SamplesTranscriptional profiling revealed that murine VH11 and non-VH11 CLL differed in the upregulation of specific pathways implicated in cell signaling and metabolism. We identified a gene expression signature (including Ccdc88a, Clip3, Zcchc18, Chd3 and Itm2a) that was significantly upregulated in T cell-dependent non-VH11 CLL compared with T cell-independent VH11/Vk14 or mutated IgH.TEµ CLL. Overall design: biological replicate (n=3-4) RNA-Seq experiments Please note that the ''countTable_exons_def_norm_rpkm_all.txt'' contains the ''FPKM'' column headers (as a default output setting for the HOMER software package). However, the .txt file contains RPKM value as described in the sample data processing field.
Identification of Distinct Unmutated Chronic Lymphocytic Leukemia Subsets in Mice Based on Their T Cell Dependency.
Specimen part, Cell line, Subject
View Samples