Project description:The efficacy of glucocorticoid receptor modulation is well established in Acute Lymphoblastic Leukemia(ALL) but the response remains heterogeneous and limited by emergence of drug resistance. Here we use, two clonally-derived cell lines (CEM-C1 and CEM-C7) from a 3-year-old T-cell ALL patient, as a model system to understand the mechanisms of drug resistance in these cell lines; the clone CEM-C1 is resistant to dexamethasone-induced apoptosis and CEM-C7 is sensitive. We performed ATACseq and RNAseq to query for TF binding motifs present in the open regions of the chromatin and expression levels of TFs that could recognize the identified motifs. We are experimentally validating our hypothesis that depletion of the TFs identified, either singly or in combination, in CEM-C7 cells will cause dexamethasone resistance in CEM-C7 cells.
Project description:C7 is a novel lytic cycle inducer of Epstein-Barr virus (EBV) in EBV-positive epithelial cells. To analyze the potential signaling pathways that are activated by C7 for induction of EBV lytic cycle, we performed a RNA sequencing to analyze the RNA expression profiles in AGS-BX1 gastric carcinoma cells before and after treatment with C7.
Project description:We have developed a monoclonal antibody (mAb) C7 that reacts with Als3p and enolase present in Candida albicans cell wall and exerts three anti-Candida activities: candidacidal activity and inhibition of both adhesion and filamentation. To investigate the mode of action of mAb C7 on fungal viability, we examined changes in the genome-wide gene expression profile of C. albicans grown in presence of a subinhibitory concentration of mAb C7 (12.5 µg/ml) by using microarrays. A total of 49 genes were found to be differentially expressed upon treatment with mAb C7. Of these, 28 were found to be up-regulated and 21 down-regulated. The categories of up-regulated genes with the largest number of variations were those involved in iron uptake or related to iron homeostasis (42.86%), while the energy-related group accounted for 38.10% of the down-regulated genes (8/21). Results were validated by real Time PCR. Since these effects resembled those found under iron-limited conditions, the activity of mAb C7 on C. albicans mutants with deletions in key genes implicated in the three iron acquisition systems described in this yeast was also assessed. Only mutants lacking TPK1 and TPK2 genes were less sensitive to the candidacidal effect of mAb C7. FeCl3 or hemin at concentrations ≥ 7.8µM reversed the candidacidal effect of mAb C7 on C. albicans, on a concentration dependent manner. The results presented in this study provide evidence that the candidacidal effect of mAb C7 is related to the blockage of the reductive iron uptake pathway of C. albicans. A saturated culture of C. albicans grown overnight was diluted to an optical density at 600 nm of approximately 0.1 and divided in two aliquots. One of them was used untreated as control and the second one was treated with a subinhibitory concentration (12.5 µg/ml) of monoclonal antibody C7 . Both cultures were incubated for 18 h at 37ºC before harvesting cells. Antibody added and control samples were obtained each time. The experiment was repeated once. Dye-swap technique was used for hybridization and four arrays were analyzed to compare the expresion of over six thousands genes in response to antibody C7.
Project description:Background: Dystrophic epidermolysis bullosa (DEB) is a skin blistering disease caused by mutations in COL7A1, which encodes type VII collagen (C7). There is no cure for DEB, but previous work has shown potential therapeutic benefit in increasing production of even partially functional C7. Genome-wide screens using CRISPR-Cas9 have enabled the identification of genes involved in cancer development, drug resistance, and other genetic diseases, suggesting that they could be used to identify novel drivers of C7 production. Methods: A keratinocyte C7 reporter cell line was created by integrating a tdTomato fluorescent marker into the last exon of the endogenous COL7A1 gene. A genome-wide CRISPR activation (CRISPRa) screen was performed with the C7_tdTomato reporter to identify genes and pathways that increase C7 expression. High tdTomato-expressing cells were sorted and sequenced to identify the single guide RNAs (sgRNAs) that became enriched relative to the starting material. Pathway analysis was performed on the corresponding genes to identify regulators and pathways that influence C7 expression. A targeted drug screen was performed in three different keratinocyte cell lines based on the CRISPRa screen results, and C7 upregulation was evaluated. Results: The C7_tdTomato cell line was validated as an effective reporter cell line for detection of C7 upregulation. The CRISPRa screen identified two genes, DENND4B and TYROBP as top hits based on enrichment in the high fluorescence population and representation with multiple sgRNAs. Pathway analysis of the CRISPRa screen showed enrichment of toll-like receptor and interferon-related upstream regulators and functions related to calcium uptake and immune signaling. Several compounds in the targeted drug screen increased C7 expression in at least one keratinocyte line, but only kaempferol, a plant flavonoid, significantly increased C7 mRNA and protein in a DEB patient line. Conclusions: The novel C7_tdTomato reporter cell line can be used to screen compounds for increased C7 expression. The CRISPRa screen combined with a fluorescent reporter cell line can be used to reveal mechanistic regulators of gene expression and therapeutic targets for rare genetic diseases. Kaempferol has shown promising results in increasing C7 production and should be further evaluated as a potential therapeutic for DEB patients.
Project description:We have developed a monoclonal antibody (mAb) C7 that reacts with Als3p and enolase present in Candida albicans cell wall and exerts three anti-Candida activities: candidacidal activity and inhibition of both adhesion and filamentation. To investigate the mode of action of mAb C7 on fungal viability, we examined changes in the genome-wide gene expression profile of C. albicans grown in presence of a subinhibitory concentration of mAb C7 (12.5 µg/ml) by using microarrays. A total of 49 genes were found to be differentially expressed upon treatment with mAb C7. Of these, 28 were found to be up-regulated and 21 down-regulated. The categories of up-regulated genes with the largest number of variations were those involved in iron uptake or related to iron homeostasis (42.86%), while the energy-related group accounted for 38.10% of the down-regulated genes (8/21). Results were validated by real time PCR. Since these effects resembled those found under iron-limited conditions, the activity of mAb C7 on C. albicans mutants with deletions in key genes implicated in the three iron acquisition systems described in this yeast was also assessed. Only mutants lacking TPK1 gene, and TPK2 to a lesser extent were less sensitive to the candidacidal effect of mAb C7. FeCl3 or hemin at concentrations ≥ 7.8µM reversed the candidacidal effect of mAb C7 on C. albicans, on a concentration dependent manner. The results presented in this study provide evidence that the candidacidal effect of mAb C7 is related to the blockage of the reductive iron uptake pathway of C. albicans.
Project description:We identified a rare coding variant (p.K420Q) in the complement component 7 (C7) gene affecting the risk of Alzheimer's disease. To investigate the cellular effects of the mutant, we performed RNA-seq in cell line overexpression wilt-type and mutant C7. U251 glioma cells with stable expression of mutant APP (K670N/M671L) (U251-APP cells), which produce Aβ42 under Dox inducing, were used as the model cell. Total RNA of U251-APP cells overexpressing wild type and mutant C7 proteins were subjected to transcriptome sequencing using Illumina Hiseq 4000 platform.
Project description:We use the zebrafish embryo model to study the innate immune response against Mycobacterium marinum. Therefore, we injected M. marinum into the yolk at the 64 cell stage and took samples at 5 days post injection. This deep sequence study was designed to determine the gene expression profile by Mycobacterium marinum infection. RNA was isolated from embryos at 5 days post injection. Wildtypes zebrafish embryos were micro-injected into the yolk (64 cell stage) with 40 CFU of Mycobacterium marinum E11 mCherry bacteria suspended in PVP (Polyvinylpyrrolidone), or Non-injected as a control. After injections embryos were transferred into fresh egg water and incubated at 28M-BM-0C. At 5 days post injection 50 embryos per group were snap-frozen in liquid nitrogen, and total RNA was isolated using TRIZOL reagent.