Type 1 diabetes (T1D) is an autoimmune disease in which pancreatic islet β-cells are attacked by the immune system, resulting in insulin deficiency and hyperglycemia. One of the top non-synonymous single-nucleotide polymorphisms (SNP) associated with T1D is in the interferon-induced helicase C domain-containing protein 1 (), which encodes an anti-viral cytosolic RNA sensor. This SNP results in an alanine to threonine substitution at amino acid 946 () and confers an increased risk for several autoimmune diseases, including T1D.
View Article and Find Full Text PDFType 1 diabetes (T1D) is an autoimmune disease in which pancreatic islet β-cells are attacked by the immune system, resulting in insulin deficiency and hyperglycemia. One of the top non-synonymous single-nucleotide polymorphisms (SNP) associated with T1D is in the interferon-induced helicase C domain-containing protein 1 ( ), which encodes an anti-viral cytosolic RNA sensor. This SNP results in an alanine to threonine substitution at amino acid 946 (IFIH1 ) and confers an increased risk for several autoimmune diseases, including T1D.
View Article and Find Full Text PDFThe single-nucleotide polymorphism (SNP) rs3184504 is broadly associated with increased risk for multiple autoimmune and cardiovascular diseases. Although the allele is uniquely enriched in European descent, the mechanism for the widespread selective sweep is not clear. In this study, we find the rs3184504*T allele had a strong association with reduced mortality in a human sepsis cohort.
View Article and Find Full Text PDFSAMD9L is an interferon-induced tumor suppressor implicated in a spectrum of multisystem disorders, including risk for myeloid malignancies and immune deficiency. We identified a heterozygous de novo frameshift variant in SAMD9L in an infant with B cell aplasia and clinical autoinflammatory features who died from respiratory failure with chronic rhinovirus infection. Autopsy demonstrated absent bone marrow and peripheral B cells as well as selective loss of Langerhans and Purkinje cells.
View Article and Find Full Text PDFTYK2 is a JAK family member that functions downstream of multiple cytokine receptors. Genome wide association studies have linked a SNP (rs34536443) within encoding a Proline to Alanine substitution at amino acid 1104, to protection from multiple autoimmune diseases including systemic lupus erythematosus (SLE) and multiple sclerosis (MS). The protective role of this SNP in autoimmune pathogenesis, however, remains incompletely understood.
View Article and Find Full Text PDFThe single-nucleotide polymorphism rs1990760 in the gene encoding the cytosolic viral sensor IFIH1 results in an amino-acid change (A946T; IFIH1) that is associated with multiple autoimmune diseases. The effect of this polymorphism on both viral sensing and autoimmune pathogenesis remains poorly understood. Here we found that human peripheral blood mononuclear cells (PBMCs) and cell lines expressing the risk variant IFIH1 exhibited heightened basal and ligand-triggered production of type I interferons.
View Article and Find Full Text PDFMacroautophagy is an evolutionarily conserved cellular process involved in the clearance of proteins and organelles. Although the cytoplasmic machinery that orchestrates autophagy induction during starvation, hypoxia, or receptor stimulation has been widely studied, the key epigenetic events that initiate and maintain the autophagy process remain unknown. Here we show that the methyltransferase G9a coordinates the transcriptional activation of key regulators of autophagosome formation by remodeling the chromatin landscape.
View Article and Find Full Text PDFThe Arp2/3-activator Wiskott-Aldrich syndrome protein and Scar homologue (WASH) is suggested to regulate actin-dependent membrane scission during endosomal sorting, but its cellular roles have not been fully elucidated. To investigate WASH function, we generated tamoxifen-inducible WASH-knockout mouse embryonic fibroblasts (WASHout MEFs). Of interest, although EEA1(+) endosomes were enlarged, collapsed, and devoid of filamentous-actin and Arp2/3 in WASHout MEFs, we did not observe elongated membrane tubules emanating from these disorganized endomembranes.
View Article and Find Full Text PDFThe Ras GTPase-activating-like protein IQGAP1 is a multimodular scaffold that controls signaling and cytoskeletal regulation in fibroblasts and epithelial cells. However, the functional role of IQGAP1 in T cell development, activation, and cytoskeletal regulation has not been investigated. In this study, we show that IQGAP1 is dispensable for thymocyte development as well as microtubule organizing center polarization and cytolytic function in CD8(+) T cells.
View Article and Find Full Text PDFTo identify physiologically relevant WT1 transcriptional target genes in prostate cancer cells, we have established stably transfected LNCaP cell lines expressing either WT1(A), its mutant counterpart DDS(R384W), or vector control. Microarray analyses of these cells revealed that vascular endothelial growth factor (VEGF) was differentially expressed in the engineered lines. Regulation of VEGF by WT1 likely contributes to kidney angiogenesis during development and WT1 mutants such as DDS(R384W) are associated with the Denys-Drash syndrome (DDS), characterized by renal abnormalities.
View Article and Find Full Text PDFUnderstanding angiogenesis and growth control is central for elucidating prostate tumorigenesis. However, the mechanisms of activation of the angiogenic gene, vascular endothelial growth factor (VEGF) are complex and its regulation in prostate cancer is not well understood. In previous studies, VEGF expression levels were correlated with altered levels of the zinc finger transcription factor, WT1.
View Article and Find Full Text PDFThe zinc finger transcription factor, WT1, regulates many growth control genes, repressing or activating transcription depending on the gene and cell type. Based on earlier analyses of the effect of WT1 on androgen responsive genes, we hypothesized that there may be an interaction between the androgen signaling pathway and WT1, such that the commonly used Renilla luciferase control vectors were activated in LNCaP prostate cancer cells. Using cotransfection assays we tested the effects of WT1 and/or the androgen analog, R1881, on two Renilla luciferase vectors, pRL-SV40 and the promoter-less pRL-null.
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