Project description:To investigate the altered gene expression levels in MSR1 knockout and wild type macrophages in co-culture with BMSCs. Each group had a biological repeat (n=3). Results provide insight into the role of MSR1 in macrophages in a co-culture system.
Project description:To characterize the genetic basis of hybrid male sterility in detail, we used a systems genetics approach, integrating mapping of gene expression traits with sterility phenotypes and QTL. We measured genome-wide testis expression in 305 male F2s from a cross between wild-derived inbred strains of M. musculus musculus and M. m. domesticus. We identified several thousand cis- and trans-acting QTL contributing to expression variation (eQTL). Many trans eQTL cluster into eleven ‘hotspots,’ seven of which co-localize with QTL for sterility phenotypes identified in the cross. The number and clustering of trans eQTL - but not cis eQTL - were substantially lower when mapping was restricted to a ‘fertile’ subset of mice, providing evidence that trans eQTL hotspots are related to sterility. Functional annotation of transcripts with eQTL provides insights into the biological processes disrupted by sterility loci and guides prioritization of candidate genes. Using a conditional mapping approach, we identified eQTL dependent on interactions between loci, revealing a complex system of epistasis. Our results illuminate established patterns, including the role of the X chromosome in hybrid sterility.
Project description:Bone marrow derived stromal cells (BMSCs) are a multipotent population that supports angiogenesis, wound healing, immunomodulation and plays an active role in the hematopoietic niche. On the other hand, they are also involved in the nurturing of bone marrow tumors and metastasis, showing a pro-tumorigenic behavior. BMSCs secrete a wide range of cytokines, growth factors and matrix proteins that are likely responsible for many of these effects. However, it is not clear whether this pro-tumorigenic behavior of BMSCs is induced by the tumor cells, neither in what extent the tumor cells affect the type and quantity of factors produced by BMSCs. To determine how tumor cells that arise from bone marrow affect the BMSCs, we selected three myeloid leukemia cell lines (TF-1, TF-1alpha and K562) and co-cultured them with BMSCs from healthy donors. We found that, under co-culture condition, the gene expression profiling of BMSCs revealed up-regulation of many pro-inflammatory signaling related genes, mainly IL-17 signaling-related genes. Moreover, IL-17 signaling-related cytokines CCL2 and IL8, were increased in co-culture supernatants. We conclude that BMSCs react to the presence of leukemia cells undergoing changes in the cytokine and chemokine secretion profile. Thus, BMSCs and leukemia cells both contribute to the creation of a competitive niche more favorable to leukemia stem cells. BMSCs from healthy donors were transwell co-cultured with three different myeloid leukemia cell lines: TF-1 (n=3), TF-1alpha (n=3) and K562 (n=3). A 1-um Transwell system (BDBiosciences, San Jose, CA USA) was used to maintain the cultured BMSC and leukemia cell populations separate from each other. As a control BMSCs were also transwell co-cultured under the same conditions with CD34+ cells (n=9) isolated from G-CSF-mobilized peripheral blood stem cells from healthy donors. An alternative co-culture method was used to analyze BMSCs and leukemia cells in direct contact: TF-1 (n=3), TF-alpha (n=3) and K562 (n=3). The two populations were cultured together in the same well without any membrane separation. BMSCs (n=18), TF-1 (n=3), TF-1alpha (n=3), K562 (n=3) and CD34+ (n=9) cells cultured alone (mono-cultures) were used as controls. Cells from both mono- and co-culture conditions were harvested at 4h, 10h, and 24h.
Project description:Lupus nephritis (LN), a severe complication of systemic lupus erythematosus (SLE), is driven by immune complex deposition and inflammatory renal injury. This study uncovers a novel mechanism in which podocyte-derived angiopoietin-like protein 3 (ANGPTL3) exacerbates LN pathogenesis through macrophage scavenger receptor 1 (MSR1)-mediated activation. Protein interaction screening revealed direct binding between ANGPTL3 and MSR1, a macrophage-enriched receptor. Clinical analyses demonstrated elevated glomerular expression of ANGPTL3 and MSR1 in LN patients, correlating with reduced renal function and histopathological damage. In vitro, ANGPTL3-overexpressing podocytes activated macrophages in an MSR1-dependent manner. RNA sequencing of ANGPTL3-stimulated bone marrow-derived macrophages (BMDMs) identified robust activation of interferon signaling pathways, with key genes (Tnip3, Isg20). Silencing Msr1 abolished these effects, suppressing interferon-related gene expression. In the pristane-induced lupus model, ANGPTL3 and MSR1 co-localized with infiltrating macrophages in injured glomeruli, mirroring human LN pathology. These findings establish the ANGPTL3-MSRI axis as a critical driver of macrophage activation and interferon signaling in LN, highlighting ANGPTL3 as a promising therapeutic target to mitigate immune-mediated renal injury in SLE.
