Loss of Trex1 in dendritic cells is sufficient to trigger systemic autoimmunity
ABSTRACT: Biallelic defects of the gene encoding for the intracellular enzyme 3’ repair exonuclease (Trex)1 cause Aicardi-Goutières syndrome (AGS), a rare monogenic, lupus-like autoimmune disease, while heterozygous Trex1 loss of function alleles are associated with systemic lupus erythematosus (SLE). Trex1-/- mice develop lethal autoimmune multi-organ inflammation, which results from a chronic type I IFN response triggered by intracellular accumulation of a putative nucleic acid substrate of Trex1. This pathogenic nucleic acid is detected by the broadly, but not ubiquitously, expressed cytosolic DNA sensor cGAS, raising the question whether there are specific cell types that respond to Trex1 deficiency by production of IFN and induce autoimmunity. We generated mice with conditional knock out of the Trex1 gene and demonstrated that loss of Trex1 throughout the hematopoietic system and even selective loss in dendritic cells is sufficient to cause IFN release and autoimmunity. B cells showed no transcriptional response to Trex1 deficiency. Trex1-/- keratinocytes produced IFN but did not induce skin inflammation, whereas loss of Trex1 in cardiomyocytes triggered neither IFN response nor pathology. Trex1-deficient neurons and astrocytes did not release IFN in the CNS. In contrast, mice with selective inactivation of Trex1 in long-living CNS macrophages such as microglia locally produced IFN but did not reproduce the mild encephalitis seen in Trex1-/- mice. Collectively, individual cell types differentially respond to the loss of Trex1 and dendritic cells seem promising candidates for experiments addressing the molecular pathomechanism in Trex1 deficiency. We sorted CD19-positive B cells from spleens of Trex1fl/fl CD19-Cre+ and Trex1fl/fl CD19-Cre- mice and isolated total RNA for library construction to perform mRNA deep sequencing.
Project description:Histone acetylation is sensitive to metabolic cues, however interplay between histone acetyl transferases and cellular metabolism remains poorly understood. Here we report the localization of a classical nuclear HAT- MOF and members of Non-Specific Lethal complex in mitochondria. MOF regulates expression of oxidative phosphorylation (OXPHOS) genes, residing in both nuclear and mitochondrial genomes, selectively in aerobically respiring cells. Furthermore, MOF/KANSL1 depletion causes impaired mitochondrial translation and reduced respiration. MOF loss is catastrophic for tissues with high-energy consumption. In mouse hearts, Mof knockout causes hypertrophic cardiomyopathy, compromised ventricular contractility/ stroke volume and ultimately leads to cardiac failure within three weeks of birth. RNA-seq analysis of the cardiomyocytes revealed deregulation of mitochondrial nutrient metabolism and OXPHOS pathways. Consistently, electron microscopy on affected tissues revealed mitochondrial deterioration with high tissue heterogeneity, commonly observed in mitochondrial diseases. Thus, we reveal a novel function of MOF in mitochondrial homeostasis and propose MOF as a sensor connecting epigenetic regulation to metabolism. We generated mRNA-seq profile of Mof depleted HeLa cells adapted in glucose or galactose media. We also present nuclear RNA seq profile from Mof deleted cardiomyocytes.
Project description:Background: Niemann-Pick type C is a rare autosomal recessive lysosomal storage disorder presenting aggravating neurologic symptoms due degeneration of specific types of CNS neurons. At present, it is not well understood how neurons react to NPC1 deficiency and why some neuronal cell types are more vulnerable than others. Purpose: We took aimed to uncover how a specific type of CNS neuron that can be highly purified reacts to NPC1 deficiency based on changes in gene expression. Methods: Retinal ganglion cells were purified from individual one-week old Balb/c mice homozygous for a mutant NPC1 allele (NPC1m1N) and wildtype littermates (n = 4 mice each genotype) using immunopanning. Total RNA was isolated from acutely isolated neurons and subjected to RNAseq using 4 biological replicates for each genotype. Results: Our analysis revealed a strong downregulation of transcripts known to be decreased in mutant mice including Npc1 and Calb1 thus validating our approach. We observed a strong upregulation of genes for cellular cholesterol accretion and the downregulation of those for cholesterol release. Other changes including downregulation genes involved in the immune response and synaptic components. Conclusions: The observed changes suggest that neurons already at one week of age sense a cholesterol deficit because lipids accumulate in the endosomal-lysosomal system and cannot be redistributed intracellularly. Gene expression analysis by RNAseq in retinal ganglion cells acutely purified from eight-days-old NPC1-deficient mice and wildtype littermates
Project description:We have ablated TAF10 in the erythroid compartment only by crossing the TAF10lox mice with the EpoR-Cre mice and we have studied the development of the erythroid cells in vivo. TAF10 ablation led to embryonic death at E13.5 while at E12.5 there was a clear developmental defect which was reflected in the transcriptional profile of the fetal liver cells. Gata1-target genes were mostly affected and were responsible for the lethal phenotype. mRNA from E12.5 fetal livers of TAF10lox/KO:EpoR-Cre+/- (TAF10KO) mice, TAF10HET and WT mice was profiled by NGS (Illumina).
Project description:We analyzed the role of MOF in primary MEFs and differentiated podocytes in response to Adriamycin. Mof was deleted in MEFs using the Cre-ERT2 trasgene, while Mof was knockdown in podocytes using shRNA infection. Samples were treated with Adriamycin for 24 hours and gene expression changes analysed. Analysis of gene expression changes upon Mof depletion in two cell lines, MEFs and podocytes, with and without Adriamycin
Project description:We compare the performance of two library preparation protocols (poly(A) and exome capture) in in vitro degraded RNA samples VcaP cell were grown, and treated with MDV3100 (enzalutamide) or DHT (dihydrotestosterone), intact RNA was isolated and samples were prepared in technical triplicates using two library preparation protocol. Also cells were subject to in vitro degradation through incubation of the whole cell lysate in 37C for increasing amounts of time. Following incbation paired capture and poly(A) libraries were prepared.
Project description:The IgH 3’ regulatory region (3’RR) controls class switch recombination (CSR) and somatic hypermutation (SHM) in B cells. The mouse 3’RR contains four enhancer elements with hs1,2 flanked by inverted repeated sequences and the center of a 25-kb palindrome bounded by two hs3 enhancer inverted copies (hs3a and hs3b). hs4 lies downstream of the palindrome. Evolution maintained in mammals this unique palindromic arrangement suggesting that it is functionally significant. We report that deconstructing the palindromic IgH 3’RR strongly impacts its function even when enhancers are preserved. CSR and IgH transcription appear poorly dependent from the 3’RR architecture and are more or less preserved provided 3’RR enhancers are present. By contrast, an “architectural effect” significantly lowers VH germline transcription, AID recruitment and SHM. In conclusion, this work indicates that the IgH 3’RR does not simply pile up enhancer units but also optimally expose them into a functional architecture of crucial importance. RNAseq analysis of B-cell splenocytes with (S=stimulated) or without (R=resting) LPS activation from wt, delta2leftPAL, and deltaIRIS mice.
Project description:We evaluated by RNA-seq obveral transcripts in B cells (resting and activated for 2 days with LPS) sorted from several KO mice models devoid of portion or all the IgH 3' Regulatory Region One RNA-seq point was realized per condition (resting or stimulated) and per genotype. Each point corresponds to a pool of equivalent number of B cells sorted from 4 animals
Project description:We constructed a polycistronic lentiviral vector to overexpress 3 germ cell specific genes (Stella, Oct4 and Nanos2) in mouse embryonic fibroblast (MEFs) and evaluated the transcriptome portrait in partially reprogrammed cells.We sequenced RNA samples from bulk cell population of two biological duplicates of MEF-GFP (control) and MEF-SON (overexpressed) 21 days post infection. Differential expression analysis of 50 M pair-end read per samples showed overexpression of neurogenesis, blood vessel and proliferation related genes and downregulation of chondroitin sulphate metabolic process, nitric oxide production and innate immune response genes. Examination of whole transcriptome following concurrent overexpression of Stella, Oct4 and Nanos2 in MEFs.
Project description:Differentiation of naïve CD4+ T cells into effector (Th1, Th2 and Th17) and induced regulatory (iTreg) T cells requires lineage-specifying transcription factors and epigenetic modifications that allow appropriate repression or activation of gene transcription. The epigenetic silencing of cytokine genes is associated with the repressive H3K27 trimethylation mark, mediated by Ezh2 or Ezh1 methyltransferase components of the polycomb repressive complex 2 (PRC2). EZH2 over-expression and activating mutations are implicated in tumorigenesis and correlate with poor prognosis in several tumor types 35. This spurred the development of EZH2 inhibitors which, by inducing tumor cell growth arrest and cell death, show therapeutic promise in cancer. A role for Ezh2 in suppressing Th1 and Th2 cytokine production and survival has recently been reported. It is not entirely clear whether Ezh2-PRC2 plays a role in H3K27me3 in cytokine loci in naïve CD4+ T cells and whether H3K27me3 has a non-redundant role in T helper cell lineage differentiation and survival. Here, we investigate the effects of T cell-specific Ezh2 deletion to determine the role that Ezh2-PRC2 plays in regulating the fate of differentiating naïve CD4+ T cells. Loss of Ezh2 altered the expression of 1328 genes in Th0 and 1979 genes in iTreg cells. Gene expression changes were positively correlated in both cell types, indicating that Ezh2 targets similar genes in these cells. As expected, Ifng was one of the genes most increased in expression by following loss of Ezh2. In addition, expression of Tbx21 homolog Eomes, a transcription factor that regulates IFNG production, was also significantly increased. We then performed H3K27me3 ChIP-seq on Ezh2fl/fl and Ezh2fl/fl.CD4Cre Th0 cells. Consistent with cellular phenotype and RNA-seq data, we observed a loss of the H3K27me3 at Eomes, Il4 and Il10 loci . Very low levels of H3K27me3 marks were present at Ifng and Tbx21 loci in differentiated Ezh2fl/fl Th0 cells, suggesting that upon differentiation, upregulation or activation of transcription factors accounts for IFNG overproduction. A significant loss of H3K27me3 was observed >2kb upstream of Gata3 locus , however this did not result in increased transcription . Of the 22381 genes tested for changes in H3K27me3, 1360 showed a statistically significant decrease in Ezh2fl/fl.CD4Cre Th0 cells, compared to wildtype. Furthermore, 404 of these genes also showed a concomitant gain in expression in Ezh2fl/fl.CD4Cre Th0 cells, suggesting that these loci are likely direct Ezh2-PRC2 targets. There are 3 biological replicates each of Ezh2fl/fl.CD4Cre and Ezh2fl/fl in both Th0 and iTreg cells for the RNA-seq experiment. There are 2 biological replicates each of Ezh2fl/fl.CD4Cre and Ezh2fl/fl in Th0 cells for the ChIP-seq experiment.
Project description:Physiologically relevant concentrations of retinoic acid are added to Mouse ES cells and a time course (0-72 hours) is examined with expression tiling arrays and RNA-seq to characterize the early dynamics of expression of coding and non-coding RNAs in and around the Hox clusters. Gene expression is examined at various timepoints (0-72 hrs) after retinoic acid induced neuronal differentiation