Project description:We used single-cell RNA-sequencing to investigate the role of brain-resident microglia versus infiltrating cells in a mouse model of breast cancer brain metastasis (BCBM). We generated brain metastases with a cardiac-injection of the human triple-negative breast cancer cell line MDA-MB-231BR2 (231BR) into Foxn1 nu/nu mice and allowed tumors to grow in the brain for four weeks. We then compared astrocytes (ASCA2+CD45-) and myeloid cells (CD11b+CD45+) from these mice verses control Foxn1 nu/nu brains to find transcriptional changes associated with BCBM.
Project description:Normal thymic T cell development is enabled by a stromal microenvironment most importantly composed of distinct epithelial cell populations in cortex and medulla. Their differentiation, growth and function require the expression of the transcription factor Foxn1. Direct targets of Foxn1 have, however, remained largely undefined. Utilizing newly created static and inducible genetic model systems, we now provide a genome wide map of Foxn1 target genes and the sequences bound by this master regulator. Foxn1 controls not only essential steps early in intrathymic lymphoid development including T cell lineage commitment but is also indispensable for later stages in T cell maturation such as the selection of CD4 and CD8 T cells. Thus, Foxn1 function critically choreographs both early and late events in thymic lympho-stromal cross-talk. Foxn1 ChIP-seq and RNA-seq in mouse models of hypofunctional or conditional knock-out of Foxn1 Brief sample descriptions are shown below: Foxn1 ChIP-seq (GSM1945905) - chromatin immunoprecipitated using an antibody against FOXN1-FLAG (wt*); 2 samples Input ChIP-seq (GSM1945906) - input chromatin; 2 samples 42cT (GSM1945907) - RNA-seq on wt*/-::nu/nu cTEC; 3 samples 42mT (GSM1945908) - RNA-seq on wt*/-::nu/nu mTEC; 2 samples 96cT (GSM1945909) - RNA-seq on wt*/wt*::nu/nu cTEC; 3 samples 96mT (GSM1945910) - RNA-seq on wt*/wt*::nu/nu mTEC; 2 samples NcT (GSM1945911) - RNA-seq on Dox-treated TetO- iFoxn1(del7,8) cTEC; 5 samples PcT (GSM1945912) - RNA-seq on Dox-treated TetO+ iFoxn1(del7,8) cTEC; 5 samples C57BL/6 mice (GSM1945913) - ATAC-seq on wild-type cTEC; 1 sample Please see each sample for more detailed information.
Project description:Purpose: we aimed at identify and compare the transcriptional changes of ALDH- and ALDH+ DU145 xenografts upon radiotherapy treatment. Method: Xenografts were generated by injection of ALDH- and ALDH+ DU145 cells in male NMRI-Foxn1 nu/nu immune-deficient mice and subjected to fractionated irradiation to a final dose of 50 Gy. Tumors were excised and processed for total RNA extraction and RNAseq analysis.
Project description:Traumatic spinal cord injury (SCI) triggers a neuro-inflammatory response dominated by tissue-resident microglia and monocyte derived macrophages (MDMs). Since activated microglia and MDMs are morphologically identical and express similar phenotypic markers in vivo, identifying injury responses specifically coordinated by microglia has historically been challenging. Here, we pharmacologically depleted microglia and use anatomical, histopathological, tract tracing, bulk and single cell RNA sequencing to reveal the cellular and molecular responses to SCI controlled by microglia. We show that microglia are vital for SCI recovery and coordinate injury responses in CNS-resident glia and infiltrating leukocytes. Depleting microglia exacerbates tissue damage and worsens functional recovery. Conversely, restoring select microglia-dependent signaling axes, identified through sequencing data, in microglia depleted mice prevents secondary damage and promotes recovery. Additional bioinformatics analyses reveal that optimal repair after SCI and likely other forms of neurological disease, might be achieved by co-opting key ligand-receptor interactions between microglia, astrocytes and MDMs.
Project description:The transcription factor FOXN1 is a master regulator of thymic epithelial cell development and function. Here we demonstrate that FOXN1 expression is differentially regulated during organogenesis and participates in multi-molecular nuclear condensates essential for the factor's transcriptional activity. FOXN1's C-terminal sequence regulates the diffusion velocity within these aggregates and modulates the binding to proximal gene regulatory regions. These dynamics are significantly altered in a patient's FOXN1 mutant modified in its C-terminal sequence. This mutant is transcriptionally inactive and acts as a dominant negative factor displacing wild-type FOXN1 from condensates and causing athymia and severe lymphopenia in heterozygotes. Expression of the mutated mouse ortholog, Foxn1, selectively impairs mouse thymic epithelial cell (TEC) differentiation, revealing a gene dose dependency for individual TEC subtypes. We have therefore identified the cause for a primary immunodeficiency disease and determined the mechanism by which this FOXN1 gain-of-function mutant mediates its dominant negative effect.
Project description:FOXN1 is a transcription factor critical for the development of both thymic epithelial cell (TEC) and hair follicle cell (HFC) compartments. However, mechanisms controlling its expression remain poorly understood. To address this question, we performed thorough analyses of the conservation and chromatin status of the Foxn1 locus in different tissues and states, and identified several putative cis-regulatory regions unique to TEC vs. HFC. Furthermore, experiments using genetically modified mice with specific deletions in the Foxn1 locus and additional bioinformatic analyses helped us identify key regions and transcription factors involved in either positive or negative regulation of Foxn1 in both TEC and HFC. Specifically, we identified SIX1 and FOXN1 itself, as key factors inducing Foxn1 expression in embryonic and neonatal TECs. Together, our data provide important mechanistic insights into the transcriptional regulation of the Foxn1 gene in TEC vs. HFC and highlight the role of FOXN1 in its autoregulation
Project description:FOXN1 is a transcription factor critical for the development of both thymic epithelial cell (TEC) and hair follicle cell (HFC) compartments. However, mechanisms controlling its expression remain poorly understood. To address this question, we performed thorough analyses of the conservation and chromatin status of the Foxn1 locus in different tissues and states, and identified several putative cis-regulatory regions unique to TEC vs. HFC. Furthermore, experiments using genetically modified mice with specific deletions in the Foxn1 locus and additional bioinformatic analyses helped us identify key regions and transcription factors involved in either positive or negative regulation of Foxn1 in both TEC and HFC. Specifically, we identified SIX1 and FOXN1 itself, as key factors inducing Foxn1 expression in embryonic and neonatal TECs. Together, our data provide important mechanistic insights into the transcriptional regulation of the Foxn1 gene in TEC vs. HFC and highlight the role of FOXN1 in its autoregulation
Project description:FOXN1 is a transcription factor critical for the development of both thymic epithelial cell (TEC) and hair follicle cell (HFC) compartments. However, mechanisms controlling its expression remain poorly understood. To address this question, we performed thorough analyses of the conservation and chromatin status of the Foxn1 locus in different tissues and states, and identified several putative cis-regulatory regions unique to TEC vs. HFC. Furthermore, experiments using genetically modified mice with specific deletions in the Foxn1 locus and additional bioinformatic analyses helped us identify key regions and transcription factors involved in either positive or negative regulation of Foxn1 in both TEC and HFC. Specifically, we identified SIX1 and FOXN1 itself, as key factors inducing Foxn1 expression in embryonic and neonatal TECs. Together, our data provide important mechanistic insights into the transcriptional regulation of the Foxn1 gene in TEC vs. HFC and highlight the role of FOXN1 in its autoregulation