Project description:Endothelial-to-mesenchymal transition (EndMT) in which endothelial cells lose their characteristics and acquire mesenchymal property has recently been recognized as a driver of disease progression in wide range of pathologies. However, the regulatory mechanism of EndMT has not been fully understood. Here, we found that combined knockdown of two ETS family transcription factors, ERG and FLI1, induced EndMT. Hence, we analyzed functions of ERG and FLI1 using gene expression microarray and ChIP-seq to elucidate the regulatory mechanism of EndMT.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:Endothelial-to-mesenchymal transition (EndMT) in which endothelial cells lose their characteristics and acquire mesenchymal property has recently been recognized as a driver of disease progression in wide range of pathologies. However, the regulatory mechanism of EndMT has not been fully understood. Here, we found that combined knockdown of two ETS family transcription factors, ERG and FLI1, induced EndMT. Hence, we analyzed functions of ERG and FLI1 using gene expression microarray and ChIP-seq to elucidate the regulatory mechanism of EndMT.
Project description:ERG and FLI1 are important regulators of angiogenesis, but their role in lymphatic vasculature is less known. The goal of this study was to determine the role of ERG and FLI1 in postnatal lymphangiogenesis and their involvement in SSc lymphatic system defects. IF were used to detect ERG and FLI1 in SSc and healthy controls (HC) skin biopsies. Human lymphatic endothelial cells (LECs) were used in cell culture experiments. Transcriptional and chromatin analysis of ERG or FLI1 silenced LECs was performed using microarrays and ATAC-seq, respectively. Effects of ERG and FLI1 deficiency on in vitro tubulogenesis was examined using Matrigel assay. Erg and Fli1 endothelial specific knockouts (ErgCKO and Fli1CKO) and lymphatic specific knockouts (ProxErgCKO and ProxFli1CKO) were generated to examine vessel regeneration. ERG and FLI1 protein levels were reduced in blood and lymphatic vasculature in SSc skin biopsies. ERG and FLI1 were shown to regulate genes involved in lymphatic vessel specification, including VEGFR3/FLT4, LYVE-1, and PROX1, and this effect was, at least in part, due to chromatin remodeling. ERG/FLT4 pathway regulated in vitro tubulogenesis in LECs. Deficiency of Erg and Fli1 impaired function of blood and lymphatic vessel during wound healing. ERG and FLI1 are essential regulators of blood and lymphatic vessel regeneration. Deficiency of ERG and FLI1 in SSc endothelial cells, may contribute to rarefaction of blood and lymphatic vasculature in SSc patients. Microarray analysis was performed at The Boston University Microarray Core Facility. Affymetrix CEL files were normalized to produce gene-level expression values using the implementation of the Robust Multiarray Average (RMA) in the affy package (version 1.36.1) included within in the Bioconductor software suite (version 2.12) and an Entrez Gene-specific probe set mapping from BrainArray (version 16.0.0). RLE and NUSE quality metrics were computed using the affy PLM Bioconductor package (version 1.34.0). All microarray analyses were performed using the R environment for statistical computing (version 2.15.1).
Project description:Translocations of ETS transcription factors are driver mutations in diverse cancers. We investigated the genomic network of the ETS fusion EWS/FLI1 in Ewing's sarcoma (ESFT) as a model of ETS-driven tumorigenesis. ChIP-Seq and transcriptional analysis identified E2F3 as a principle co-factor of EWSFLI1 defining functionally distinct gene sets. While EWS/FLI1 binding independent of E2F3 predominantly associated with repressed differentiation genes, significant co-localization with E2F3 was discovered at proximal promoters of activated growth-related genes. Thus, EWS/FLI1 promotes oncogenesis by simultaneously perturbing differentiation state and augmenting the expression of genes co-regulated by E2F3. Integration of additional E2F3 and ERG localization data from prostate cancer containing TMPRSS2/ERG verified that the ETS-E2F module is also found in prostate cancer and may be of general relevance to ETS driven cancers. Timecourse with 6 timepoints of a doxicyclin inducible EWS-FLI1 knockdown in the A673 Ewing's Sarcoma celline
Project description:Transcriptional profiling of human mesenchymal stem cells comparing normoxic MSCs cells with hypoxic MSCs cells. Hypoxia may inhibit senescence of MSCs during expansion. Goal was to determine the effects of hypoxia on global MSCs gene expression.
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs. One-condition experment, gene expression of 3A6