Recent studies have shown that tissue macrophages (MF) arise from embryonic progenitors of the yolk sac (YS) and fetal liver and colonize the tissues before birth. Further studies have proposed that developmentally distinct tissue MF can be identified based on the differential expression of F4/80 and CD11b, but whether a characteristic transcriptional profile exists is largely unknown. Here, we established an inducible fate mapping system that facilitated the identification of A2 progenitors of the YS as source of F4/80hi but not CD11bhi MF. Large-scale transcriptional profiling of MF precursors from the YS until adulthood allowed the description of a complex MF pedigree. We further identified a distinct molecular signature of F4/80hi and CD11bhi MF and found that Irf8 was vital for MF maturation and the innate immune response. Our data provide new cellular and molecular insights into the origin and developmental pathways of tissue MF.
Transcriptome-based profiling of yolk sac-derived macrophages reveals a role for Irf8 in macrophage maturation.
Specimen part
View SamplesBiallelic 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. Overall design: 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.
Loss of Trex1 in Dendritic Cells Is Sufficient To Trigger Systemic Autoimmunity.
Specimen part, Subject
View SamplesMicroglia are tissue macrophages of the central nervous system (CNS) that control tissue homeostasis, and as such they are crucially important for organ integrity. Microglia dysregulation is thought to be causal for a group of neuropsychiatric, neurodegenerative and neuroinflammatory diseases, called microgliopathies. However, how the intracellular stimulation machinery in microglia is controlled is poorly understood. By using expression studies, we identified the ubiquitin-specific protease (Usp) 18 in white matter microglia that essentially contributes to microglial quiescence under homeostatic conditions. We further found that microglial Usp18 negatively regulated the activation of STAT1 and concomitant induction of interferon-induced genes thereby disabling the termination of IFN signalling. Unexpectedly, the Usp18-mediated feedback loop was independent from the catalytic domain of the protease but instead required the interacting region of Ifnar2. Additionally, the absence of Ifnar1 completely rescued microglial activation indicating a tonic IFN signal mediated by receptor interactions under non-diseased conditions. Finally, conditional depletion of Usp18 only in myeloid cells significantly enhanced the disease burden in a mouse model of CNS autoimmunity, increased axonal and myelin damage and determined the spatial distributions of CNS lesions that shared the same STAT1 signature as myeloid cells found in active multiple sclerosis (MS) lesions. These results identify Usp18 as novel negative regulator of microglia activation, demonstrate a protective role of the IFNAR pathway for microglia and establish Usp18 as potential therapeutic target for the treatment of MS.
USP18 lack in microglia causes destructive interferonopathy of the mouse brain.
Specimen part
View SamplesMicroglia are tissue macrophages of the central nervous system (CNS) that control tissue homeostasis, and as such they are crucially important for organ integrity. Microglia dysregulation is thought to be causal for a group of neuropsychiatric, neurodegenerative and neuroinflammatory diseases, called microgliopathies. However, how the intracellular stimulation machinery in microglia is controlled is poorly understood. By using expression studies, we identified the ubiquitin-specific protease (Usp) 18 in white matter microglia that essentially contributes to microglial quiescence under homeostatic conditions. We further found that microglial Usp18 negatively regulated the activation of STAT1 and concomitant induction of interferon-induced genes thereby disabling the termination of IFN signalling. Unexpectedly, the Usp18-mediated feedback loop was independent from the catalytic domain of the protease but instead required the interacting region of Ifnar2. Additionally, the absence of Ifnar1 completely rescued microglial activation indicating a tonic IFN signal mediated by receptor interactions under non-diseased conditions. Finally, conditional depletion of Usp18 only in myeloid cells significantly enhanced the disease burden in a mouse model of CNS autoimmunity, increased axonal and myelin damage and determined the spatial distributions of CNS lesions that shared the same STAT1 signature as myeloid cells found in active multiple sclerosis (MS) lesions. These results identify Usp18 as novel negative regulator of microglia activation, demonstrate a protective role of the IFNAR pathway for microglia and establish Usp18 as potential therapeutic target for the treatment of MS.
USP18 lack in microglia causes destructive interferonopathy of the mouse brain.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
USP18 lack in microglia causes destructive interferonopathy of the mouse brain.
Specimen part
View SamplesTo analyze expression differences between Trp53 pro-and deficient as well as Atm pro- and deficient murine CLL tumors developing in the E-TCL1 mouse model, we analyzed splenocytes isolated from heavily infiltrated spleens of sick mice.
Two mouse models reveal an actionable PARP1 dependence in aggressive chronic lymphocytic leukemia.
Specimen part
View SamplesWe have analysed the activity of the nuclear exosome during meiosis by deletion of TRF4, which encodes a key component of the exosome targeting complex TRAMP. We find that TRAMP mutants produce high levels of CUTs during meiosis that are undetectable in wild-type cells, showing that the nuclear exosome remains functional for CUT degradation. Lack of TRAMP activity stabilises ~1600 CUTs in meiotic cells, which occupy 40% of the binding capacity of the nuclear cap binding complex (CBC). Overall design: One sample each of Cbc2-associated RNA from wild-type and trf4-deleted cells at 6 hours of meiosis
The nuclear exosome is active and important during budding yeast meiosis.
Subject, Time
View SamplesParadoxical cryptococcosis-associated immune reconstitution inflammatory syndrome
Transcriptomic Predictors of Paradoxical Cryptococcosis-Associated Immune Reconstitution Inflammatory Syndrome.
Specimen part
View SamplesThere are a few markers available to distinguish hepatic stellate cells (HSCs), portal fibroblasts (PFs), and mesothelial cells (MCs) in the adult mouse liver.
Characterization of hepatic stellate cells, portal fibroblasts, and mesothelial cells in normal and fibrotic livers.
Specimen part
View SamplesAberrant activation of FGFR3 via overexpression or mutation is a frequent feature of bladder cancer; however, its molecular and cellular consequences and functional relevance to carcinogenesis are not well understood. In this study with a bladder carcinoma cell line expressing inducible FGFR3 shRNAs, we sought to identiy transcriptional targets of FGFR3 and investigate their contribution to bladder cancer development.
FGFR3 stimulates stearoyl CoA desaturase 1 activity to promote bladder tumor growth.
Cell line
View Samples