Surface topography impacts on cell growth and differentiation, but it is not trivial to generate homogeneous surface structures and to define the specific morphological parameters of relevance. In this study, we have compared gene expression profiles of mesenchymal stem cells (MSCs) on nanostructured groove/ridge surfaces. Patterns were generated in polyimide using multi beam laser interference. These structures affected cell size and orientation of human MSCs. Furthermore, the nano-patterns with a periodicity of 650 nm increased differentiation towards osteogenic and adipogenic lineages. However, in absence of differentiation media the surface structures did neither induce differentiation, nor lineage-specific gene expression changes as assessed by genome wide gene expression profiles with Affymetrix microarray technology. Our results demonstrate that grooves and ridges at a periodicity of 650 nm enhance the propensity of MSCs to differentiate towards adipogenic and/or osteogenic lineages but they do not directly govern lineage-specific gene expression changes.
Surface topography enhances differentiation of mesenchymal stem cells towards osteogenic and adipogenic lineages.
Specimen part, Subject
View SamplesEwing Sarcoma is the second most common solid pediatric malignant neoplasm of the bone and soft tissue. Driven by EWS/Ets, or rarely variant, oncogenic fusions, Ewing Sarcoma is a biologically and clinically aggressive disease with a high propensity for metastasis. Our laboratory has previously identified the Jumonji-domain H3K9 me 1/2 histone demethylase KDM3A as a novel oncogene downstream of EWS/Fli1, the most common oncofusion in Ewing Sarcoma. Herein, we uncover a role for KDM3A in the promotion of Ewing Sarcoma metastasis.
The histone demethylase KDM3A, and its downstream target MCAM, promote Ewing Sarcoma cell migration and metastasis.
Cell line
View SamplesThe role of topographic cues in controlling commitment of induced pluripotent stem cells (iPSCs) is largely unknown. Here we demonstrate that groove-ridge nanostructures induce the elongation of iPSC colonies, guide the orientation of apical actin fibers and direct the polarity of cell division. Elongation of iPSC colonies impacts also on the intrinsic molecular patterning which seems to be orchestrated starting from the rim of the colonies. We followed the hypothesis that nanotopography directly modulates the transcriptional program of iPSC, further to guiding the overall spatial organization of the colonies. Single iPSC were seeded on flat (PI flat) and nanostructured polyimide (PI 650) and gene expression profiles were analyzed after three days. No significant differences were observed when cells were kept under culture conditions that sustained pluripotency. Then, we analyzed gene expression changes upon two weeks of multi-lineage differentiation. Many genes revealed significant expression changes in the course of differentiation and this was more pronounced on PI flat as compared to PI 650. Comparison of iPSC that were either differentiated on flat or nanostructured biomaterials revealed differential expression of several genes. Noteworthy, among significantly regulated genes, the biggest fold change on PI 650 versus PI flat after differentiation was observed in ANKRD1, which is one of the best readouts of YAP/TAZ activity. Our study suggests that nanotopography impacts on orientation and organization of iPSC colonies and highlight a possible interaction between mechanosensors and mechanotransducers.
Surface Topography Guides Morphology and Spatial Patterning of Induced Pluripotent Stem Cell Colonies.
Specimen part, Subject
View SamplesParietal epithelial cells (PECs) are crucially involved in the pathogenesis of rapidly progressive glomerulonephritis (RPGN) as well as in focal and segmental glomerulosclerosis (FSGS). In this study, transgenic mouse lines were used to isolate pure, genetically tagged primary cultures of PECs or podocytes using FACsorting. By this approach, the morphology of primary glomerular epithelial cells in culture could be resolved: Primary podocytes formed either large cells with intracytoplasmatic extensions or smaller spindle shaped cells, depending on specific culture conditions. Primary PECs were small and exhibited a spindle-shaped or polygonal morphology. In the very early phases of primary culture, rapid changes in gene expression (e.g. of WT-1 and Pax-2) were observed. However, after prolonged culture primary PECs and podocytes still segregated clearly in a transcriptome analysis - demonstrating that the origin of primary cell cultures is important. Of the classical markers, synaptopodin and podoplanin expression were differentially regulated the most in primary PEC and podocyte cultures. However, no expression of any endogenous gene allowed to differentiate between the two cell types in culture. Finally, we show that the transcription factor WT1 is also expressed by PECs. In summary, genetic tagging of PECs and podocytes is a novel and necessary tool to derive pure primary cultures with proven origin. These cultures will be a powerful tool for the emerging field of parietal epithelial cell biology.
Primary cultures of glomerular parietal epithelial cells or podocytes with proven origin.
Specimen part
View SamplesTranscriptomes of differentiated cells of the conditionally immortalized mouse podocyte cell line SVI (Schiwek et al., Kidney Int. 66: 91-101, 2004) were determined as described in Kabgani et al. (PLoS One 7:e34907, 2012).
Primary cultures of glomerular parietal epithelial cells or podocytes with proven origin.
Specimen part, Cell line
View SamplesComparing the transcriptome of wildtype and kdm5 mutant flies in normal conditions revealed a total of 4787 genes that were significantly downregulated and thus require KDM5 for their activation, and 3269 upregulated genes that are normally repressed by KDM5 (p<0.05, FDR <0.05). Because kdm5 mutants are sensitive to the oxidizer paraquat, we also carried out RNA-seq from wildtype and kdm5 mutant adults in oxidative stress conditions. Paraquat treatment of wildtype flies lead to the upregulation of 2481, and downregulation of 3103 genes Overall design: adult mRNA profiles of 1-3-days old wild type (WT) and kdm5 mutant under normal condition and oxitative stress were generated by deep sequencing, using Illumina HisSeq 2000.
The Histone Demethylase KDM5 Activates Gene Expression by Recognizing Chromatin Context through Its PHD Reader Motif.
Sex, Specimen part, Subject
View SamplesEmbolism and the refilling of xylem vessels are intrinsic to the ability of plants to handle the transport of water under tension. While the formation of an embolized vessel is an abiotic process, refilling against the pressure gradient requires biological activity to provide both the energy and the water needed to restore xylem transport capacity.
Transcriptome response to embolism formation in stems of Populus trichocarpa provides insight into signaling and the biology of refilling.
Specimen part, Treatment
View SamplesThe present study was designed to identify Mkl1 target genes whose expression requires either the B1 site of Mkl1 and serum response factor (SRF), respectively, or the SAP domain of Mkl1. For this purpose, we obtained the transcriptomes of four stable 4T1 cell lines that either overexpress full length Mkl1-RFP (4T1-FL), Mkl1-RFP with a mutated SRF-interaction site (4T1-mutB1), Mkl1-RFP with a deletion of the SAP domain (4T1-SAP) or an empty vector encoding RFP alone (4T1 control).
Mechanism of irradiation-induced mammary cancer metastasis: A role for SAP-dependent Mkl1 signaling.
Specimen part, Cell line
View SamplesThe present study was designed to identify genes induced by irradiation in the 4T1 breast cancer model mimicking aggressive local relapse after radiotherapy. For this purpose, we obtained the transcriptomes of 4T1 tumors grown in either preirradiated (IRR+4T1) or non-irradiated (4T1) mammary tissue.
Mechanism of irradiation-induced mammary cancer metastasis: A role for SAP-dependent Mkl1 signaling.
Specimen part
View SamplesInteractions between human keratinocytes and secreted factors from Staphylococcus aureus biofilm and planktonic cultures were investigated using microarray analysis.
Staphylococcus aureus Biofilm and Planktonic cultures differentially impact gene expression, mapk phosphorylation, and cytokine production in human keratinocytes.
Treatment
View Samples