Project description:Purpose: Identify zebrafish control and csf1r-mutant brain transcriptomes Methods: RNA sequencing was performed on whole brain of control (3x), csf1ra-/- microglia (3x) and csf1ra-/-;b+/- microglia (3x) and csf1ra-/-;b-/- zebrafish. 10-20 million reads per sample were obtained. Reads were mapped to zebrafish genome GRC10. Results: We identified that microglia gene expression was reduced in csf1ra-/-;b+/- and csf1ra-/-;b-/;- mutant transcriptomes.
Project description:Purpose: Identify zebrafish control and csf1r-mutant microglia transcriptomes Methods: RNA sequencing was performed on FACS-sorted control microglia (3x), csf1ra-/- microglia (3x) and csf1ra-/-;b+/- microglia (3x). 10-20 million reads per sample were obtained. Reads were mapped to zebrafish genome GRC10. Results: We identified that csf1ra-/- or csf1ra-/-;b+/- microglia transcriptomes retain most of the microglia gene expression signature but mostly show changes in chemoklines expression.
Project description:Zebrafish wildtype adult brain and rb1-embryonal brain tumor transcriptomes were used to identify candidate rb1-interacting chromatin remodelers and epigenetic regulators altered in rb1- transformed brain tumor cells. The data was also used for comparative analysis with zebrafish rb1-/- mutant transcriptome, to identify molecular pathways that distinguish transformed rb1- tumor cells from non-transformed rb1-/- mutant cells.
Project description:Macrophage colony-stimulating factor receptor (M-CSFR/CSF1R) signaling is crucial for the differentiation, proliferation, and survival of myeloid cells. Therapeutic targeting of the CSF1R pathway is a promising strategy in many human diseases, including neurological disorders or cancer. Zebrafish are commonly used for human disease modeling and preclinical therapeutic screening. Therefore, it is necessary to understand the proper function of cytokine signaling in zebrafish to reliably model human-related diseases. Here, we investigate the roles of zebrafish csf1ra and csf1rb in adult myelopoiesis using single-cell RNA sequencing. Our analysis of adult whole kidney marrow (WKM) hematopoietic cells suggests that csf1rb is expressed mainly by blood and myeloid progenitors and that the expression of csf1ra and csf1rb is non-overlapping. We point out differentially expressed genes important in hematopoietic cell differentiation and immune response in selected WKM populations. Our findings could improve the understanding of myeloid cell function and lead to the further study of CSF1R pathway deregulation in disease, mostly in cancerogenesis.
Project description:Microglia are the resident myeloid cell in the central nervous system (CNS). Like other terminally differentiated myeloid cells, microglia rely on Csf1r signaling for survival and maintenance. Surprisingly, a small subset of microglia in the murine brain can survive without Csf1r signaling, as shown in Csf1r KO mice as well as in mice that have been treated with Csf1r inhibitor PLX5622. The nature of such Csf1r independent microglial population has not been fully characterized. Here we applied single-cell RNA-seq to examine the remaining microglia in C57/BL6J mice that were treated with PLX5622 diet (1200 mg/kg, 14 days), which results >90% microglial removal.
Project description:Tumor microenvironment-targeted therapies are emerging as promising treatment options for different tumor types. Tumor-associated macrophages/microglia (TAMs) represent the most abundant non-malignant cell type in brain metastasis and are known to support metastatic colonization and outgrowth. We used the colony-stimulating factor 1 receptor (Csf1r) inhibitor BLZ945 to target TAMs at distinct stages of the metastatic cascade in experimental breast-to-brain metastasis and demonstrate that Csf1r inhibition leads to anti-tumor responses in prevention and intervention trails. However, compensatory Csf2-mediated pro-inflammatory TAM activation blunts long-term efficacy of Csf1r inhibition by inducing signatures associated with neuroinflammation followed by wound repair responses that foster tumor recurrence. Combined blockade of Csf1r and Csf2rb-Stat5 signaling leads to sustained tumor control and a normalization of microglial activation states.
Project description:Microglia are long-lived myeloid cells in the central nervous system that are implicated in many neurological diseases. The differentiation of pluripotent stem cells provides an opportunity to develop in vitro human cellular models carrying disease gene mutations complementing existing animal models of disease. Microglia are particularly sensitive to their cellular environment and can adopt a variety of reactive states depending on different pathological conditions which may be difficult to mimic in vitro. Therefore, to best investigate human microglia in vivo, it would be helpful to generate mice whose endogenous microglia are exchanged with human cells without the need of genetic manipulation of donor cells which could alter microglia function. Colony stimulating factor 1 receptor (CSF1R) signaling is critical for microglial survival in mice, and humans with CSF1R mutations are born with fewer microglia. We made the surprising discovery that transplanted human pluripotent stem cell-derived microglia (hMG) survive pharmacological CSF1R inhibition unlike endogenous mouse microglia. Cellular assays confirmed that CSF1R signaling is necessary for human microglia survival and revealed differential CSF1R signaling with species-specific ligands. Moreover, receptor ligands and small molecule inhibitors acted in a competitive fashion. Based on these insights, we found that transient CSF1R inhibition after cell transplantation led to near-complete and wide-spread repopulation of hMGs into the mouse brain of immunodeficient mice with humanized CSF1 ligand. This approach allows the facile generation of mice whose brain microglia are replaced with genetically unmodified human cells.