Project description:Mutations in PSEN1 cause familial Alzheimer’s disease with almost complete penetrance. Age at onset is highly variable between different PSEN1 mutations and even within families with the same mutation. Current research into late onset Alzheimer’s disease implicates inflammation in both disease onset and progression. PSEN1 is the catalytic subunit of gamma-secretase, responsible for regulated intramembrane proteolysis of numerous substrates that include cytokine receptors. For this reason, we tested the hypothesis that mutations in PSEN1 impact inflammatory responses in astrocytes, thereby contributing to disease progression. We developed patient-derived models of iPSC-astrocytes, representing three lines harbouring PSEN1 mutations and six control lines (including two isogenic controls). Transcriptomic and biochemical assays were used to investigate differential inflammatory responses to TNFa, IL1a and C1q. We show that PSEN1 is upregulated in response to inflammatory stimuli, and this upregulation is disrupted by pathological PSEN1 mutations. Using transcriptomic analyses, we demonstrate that PSEN1 mutant astrocytes have an augmented inflammatory profile in their basal state, concomitant with gene expression signatures revealing dysregulated intramembrane proteolysis and JAK-STAT signalling. Detailed investigation of the JAK-STAT2 signalling pathway showed reduced cell surface expression of IFNAR2, lower STAT2 phosphorylation cascades and delayed NFκB nuclear localisation in PSEN1 mutant astrocytes in response to inflammatory stimuli, thereby implicating the notion of altered cytokine signalling cascades. Finally, we use small molecule modulators of gamma-secretase to confirm a role for PSEN1/gamma-secretase in regulating the astrocytic response to inflammatory stimuli. Together, these data suggest that mutations in PSEN1 enhance cytokine signalling via impaired regulated intramembrane proteolysis, thereby predisposing astrocytic inflammatory profiles. These findings support a two-hit contribution of PSEN1 mutations to fAD pathogenesis, not only impacting APP and Abeta processing but also altering the cellular response to inflammation.
Project description:Tyro3 is a member of the TAM (Tyro3, Axl and Mer) receptor family. In this study, we want to know potential association between Tyro3 expression in HCC and the involved signaling pathway.
Project description:The goal of this study is to compare the different biological functions between nuclear (ICD)-TYRO3- and kinase dead (KD)-TYRO3-overexpressed cells by BRD3 occupancy profiling. We revel that ICD-TYRO3-overexpressed cell were particularly enriched in negatively regulate cell death, regulation of cell cycle, regulation of vascular permeability, positively regulation of EMT, cell-cell adhesion, and regulation of phosphorylation.
Project description:Membrane-bound transcription factor CREB3L1 undergoes Regulated Intramembrane Proteolysis (RIP) in response to Hepatitis C infection. RIP activates CREB3L1 so that it can prevent the growth of HCV infected cells through the action of downstream genes. We over-expressed a truncated form of CREB3L1 that does not require RIP to enter the nucleus. Cells over-expressing this truncated form were isolated by Fluorescence Activated Cell Sorting (FACS). We used microarray to determine the downstream genes of CREB3L1 in comparison to a flow sorted empty vector control.
Project description:The goals of this study are to compare transcriptome profiling among four different cell lines including parental cells, resistant cells, Tyro3-overexpression cells, and Tyro3 knockout cells.
Project description:Membrane-bound transcription factor CREB3L1 undergoes Regulated Intramembrane Proteolysis (RIP) in response to Hepatitis C infection. RIP activates CREB3L1 so that it can prevent the growth of HCV infected cells through the action of downstream genes. We over-expressed a truncated form of CREB3L1 that does not require RIP to enter the nucleus. Cells over-expressing this truncated form were isolated by Fluorescence Activated Cell Sorting (FACS). We used microarray to determine the downstream genes of CREB3L1 in comparison to a flow sorted empty vector control. HCV Replicon-containing cells were transfected with a CREB3L1Δ381-519 to determine the downstream genes.
Project description:To better understand the molecular mechanisms underlying TYRO3 oncogenic activity in bladder carcinomas, we made use of MGH-U3, RT112 and UM-UC-5 cell lines, which were derived from a human bladder tumor and endogenously expressed the Tyro3 protein, the growth and transformation of these cell lines being dependent on Tyro3. We carried out a gene expression analysis using Affymetrix DNA arrays in this cell line treated or not withTYRO3 siRNAs.
Project description:Non-Hodgkin’s lymphomas (NHL) make up the majority of lymphoma diagnoses and represent a very diverse set of malignancies. We sought to identify kinases uniquely upregulated in different NHL subtypes. Using Multiplexed Inhibitor Bead-mass spectrometry (MIB/MS), we found Tyro3 was uniquely upregulated and important for cell survival in primary effusion lymphoma (PEL). We developed an inhibitor against Tyro3 named UNC3810A, which inhibited cell growth in PEL but not in other NHL subtypes. UNC3810A also significantly inhibited tumor progression in a PEL xenograft mouse model compared to the vehicle treated animals. Our data suggests Tyro3 may be a therapeutic target for PEL.
Project description:Mutations in PSEN1 predispose inflammation in an astrocyte model of familial Alzheimer’s disease through disrupted regulated intramembrane proteolysis