Interrogation and control of cellular fate and function using optogenetics is providing revolutionary insights into biology. Optogenetic control of cells is achieved by coupling genetically encoded photoreceptors to cellular effectors and enables unprecedented spatiotemporal control of signaling processes. Here, a fast and reversibly switchable photoreceptor is used to tune the mechanical properties of polymer materials in a fully reversible, wavelength-specific, and dose- and space-controlled manner. By integrating engineered cyanobacterial phytochrome 1 into a polyethylene glycol matrix, hydrogel materials responsive to light in the cell-compatible red/far-red spectrum are synthesized. These materials are applied to study in human mesenchymal stem cells how different mechano-signaling pathways respond to changing mechanical environments, and to control the migration of primary immune cells in 3D. This optogenetics-inspired matrix allows addressing fundamental questions of how cells react to dynamic mechanical environments. Further, remote control of such matrices could create new opportunities for tissue engineering or provide a basis for optically stimulated drug depots. Overall design: Analysis of global gene expression changes due to differences in the mechanical properties of the phytochrome-based hydrogels
Phytochrome-Based Extracellular Matrix with Reversibly Tunable Mechanical Properties.
Subject
View SamplesThe transcription factor Evi1 is essential for the formation and maintenance of hematopoietic stem cells, and induces clonal dominance with malignant progression upon constitutive activation by chromosomal rearrangements or transgene integration events. To understand the immediate and adaptive response of primary murine hematopoietic cells to the transcriptional upregulation of Evi1, we developed an inducible lentiviral vector system with a robust expression switch. We found that Evi1 delays differentiation and promotes survival in myeloid culture conditions, orchestrating a battery of genes involved in stemness (Aldh1a1, Ly6a [Sca1], Abca1, Epcam, among others). Importantly, Evi1 suppresses Cyclins and Cyclin-dependent kinases (Cdk), while it upregulates Cdk inhibitors, inducing quiescence in various proliferation-inducing cytokine conditions and operating in a strictly dose-dependent manner. Hematopoietic cells with persisting Evi1-induction tend to adopt a relatively low expression level. We thus classify Evi1 as a dormancy-inducing oncogene, likely requiring epigenetic and genetic compensation for cell expansion and malignant progression.
Activation of Evi1 inhibits cell cycle progression and differentiation of hematopoietic progenitor cells.
Specimen part
View SamplesThe transcription factor Evi1 is essential for the formation and maintenance of hematopoietic stem cells, and induces clonal dominance with malignant progression upon constitutive activation by chromosomal rearrangements or transgene integration events. To understand the immediate and adaptive response of primary murine hematopoietic cells to the transcriptional upregulation of Evi1, we developed an inducible lentiviral vector system with a robust expression switch. We found that Evi1 delays differentiation and promotes survival in myeloid culture conditions, orchestrating a battery of genes involved in stemness (Aldh1a1, Ly6a [Sca1], Abca1, Epcam, among others). Importantly, Evi1 suppresses Cyclins and Cyclin-dependent kinases (Cdk), while it upregulates Cdk inhibitors, inducing quiescence in various proliferation-inducing cytokine conditions and operating in a strictly dose-dependent manner. Hematopoietic cells with persisting Evi1-induction tend to adopt a relatively low expression level. We thus classify Evi1 as a dormancy-inducing oncogene, likely requiring epigenetic and genetic compensation for cell expansion and malignant progression.
Activation of Evi1 inhibits cell cycle progression and differentiation of hematopoietic progenitor cells.
No sample metadata fields
View SamplesMicroRNA-520f regulates EMT, as it activates CDH1 (mRNA) and E-cadherin (protein) expression, and it suppresses tumor cell invasion. We have characterized miR-520f target genes through whole genome transcriptional profiling of miRNA transfected pancreas cancer cells (PANC-1).
miRNA-520f Reverses Epithelial-to-Mesenchymal Transition by Targeting <i>ADAM9</i> and <i>TGFBR2</i>.
Cell line, Treatment
View SamplesStudies investigating the causes of autism spectrum disorder (ASD) point to genetic as well as epigenetic mechanisms of the disease. Identification of epigenetic processes that contribute to ASD development and progression is of major importance and may lead to the development of novel therapeutic strategies. Here we identify the bromodomain and extra-terminal domain containing transcriptional regulators (BETs) as epigenetic drivers of an ASD-like disorder in mice. We found that the pharmacological suppression of the BET proteins by a novel, highly selective and brain-permeable inhibitor, I-BET858, leads to selective suppression of neuronal gene expression followed by the development of an autism-like syndrome in mice. Many of the I-BET858 affected genes have been linked to ASD in humans thus suggesting the key role of the BET-controlled gene network in ASD. Our studies also suggest that environmental factors controlling BET proteins or their target genes may contribute to the epigenetic mechanism of ASD.
Autism-like syndrome is induced by pharmacological suppression of BET proteins in young mice.
Specimen part
View SamplesE47 represses Foxp3 transcription, albeit indirectly through the activation of unknown negative regulatory of Foxp3 transcription.
Id3 Maintains Foxp3 Expression in Regulatory T Cells by Controlling a Transcriptional Network of E47, Spi-B, and SOCS3.
Age, Specimen part
View SamplesIn chicks, the avian homologue of the early growth response protein-1 (ZENK) has been shown to be increased in a special cell type of the retina, the glucagonergic amacrine cells, under conditions that lead to a reduction in eye growth (myopic defocus, recovery of myopia) and decreased under conditions that enhance ocular growth (hyperopic defocus, form-deprivation). The investigation of Egr-1 knock-out mice showed that homozygous knock-out mice with no functional Egr-1 protein developed relative axial myopia at the age of 42 and 56 days, compared to heterozygous- and wildtype Egr-1 knock-out mice.
Microarray analysis of retinal gene expression in Egr-1 knockout mice.
Sex, Age, Specimen part
View SamplesThe retina plays an important regulatory role in ocular growth. To screen for new retinal candidate genes that could be involved in the inhibition of ocular growth, we used chick microarrays to analyze the changes in retinal mRNA expression after myopic defocus was imposed by positive lens-wear.
Microarray analysis of retinal gene expression in chicks during imposed myopic defocus.
Sex, Age
View SamplesIntegrated microarray and multiplex cytokine analyses of Kaposi's Sarcoma Asssociated Herpesvirus viral FLICE Inhibitory Protein K13 affected genes and cytokines in human blood vascular endothelial cells. The KSHV-encoded K13 protein is one of the few proteins to be expressed in latently-infected spindle cells and the ectopic expression of K13 in human vascular endothelial cells is sufficient to transform them into spindle cells.
Integrated microarray and multiplex cytokine analyses of Kaposi's Sarcoma Associated Herpesvirus viral FLICE Inhibitory Protein K13 affected genes and cytokines in human blood vascular endothelial cells.
Specimen part
View SamplesTransplanting renal allografts represents the major curative treatment of chronic renal failure. Despite recent advances in immunosuppressive therapy, long-term survival of allografts remains a major clinical problem. Kidney function depends in part on transport proteins such as MRP2 (ABCC2) which facilitates renal secretion of amphiphilic exogenous and endogenous compounds. Inherited variants of genes not related to the immune system have been shown to modify the outcome after renal transplantation. We investigated whether ABCC2 gene variants in the donor kidney affect renal graft function.
Multidrug resistance-related protein 2 genotype of the donor affects kidney graft function.
Sex
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