Project description:The cytosolic protein Sharpin is as a component of the linear ubiquitin chain assembly complex (LUBAC), which regulates NF-κB signaling in response to specific ligands. Its inactivating mutation in Cpdm (chronic proliferative dermatitis mutation) mice causes multi-organ inflammation, yet this phenotype is not transferable into wildtype mice by hematopoietic stem cell transfer. Recent evidence demonstrated that Cpdm mice additionally display low bone mass, but the cellular and molecular causes of this phenotype remained to be established. Here we have applied non-decalcified histology together with cellular and dynamic histomorphometry to perform a thorough skeletal phenotyping of Cpdm mice. We show that Cpdm mice display trabecular and cortical osteopenia, solely explained by impaired bone formation, whereas osteoclastogenesis is unaffected. We additionally found that Cpdm mice display a severe disturbance of articular cartilage integrity in the absence of joint inflammation, supporting the concept that Sharpin-deficiency affects mesenchymal cell differentiation. Consistently, Cpdm mesenchymal cells displayed reduced osteogenic capacitiy ex vivo, yet this defect was not associated with impaired NF-κB signaling. A molecular comparison of wildtype and Cpdm bone marrow cell populations further revealed that Cpdm mesenchymal cells produce higher levels of Cxcl5 and lower levels of IL1ra. Collectively, our data demonstrate that skeletal defects of Cpdm mice are not caused by chronic inflammation, but that Sharpin is as a critical regulator of mesenchymal cell differentiation and gene expression. They additionally provide an alternative molecular explanation for the inflammatory phenotype of Cpdm mice and the absence of disease transfer by hematopoetic stem cell transplantation. Unsorted bone marrow cells from wildtype and Cpdm mice were cultured for 10 days in the presence of ascorbic acid and ß-glycerophosphate to induce osteogenic differentiation
Project description:Our systems analysis reported here demonstrates that TLR-responses in macrophages are markedly impaired by SHARPIN deficiency, and that SHARPIN controls expression of a subset of TLR2-induced, NF-kB and AP-1 dependent genes that overlaps with those affected by the hypomorphic panr2 mutation in NEMO. 46 total RNA samples from murine bone marrow derived macrophages were analyzed (32 by Agilent array, 14 by Affymetrix Exon array) On Agilent array, the responses of macrophages to 12hr stimulation with the TLR2 ligand PAM3CSK4 (300ng/mL) were analyzed in biological duplicates for five mutant mouse strains and respective controls: Sharpin(cpdm), Ikbkg(panr2), Atf3(KO), Il10(KO), and Nfkb1(KO).
Project description:The cytosolic protein Sharpin is as a component of the linear ubiquitin chain assembly complex (LUBAC), which regulates NF-κB signaling in response to specific ligands. Its inactivating mutation in Cpdm (chronic proliferative dermatitis mutation) mice causes multi-organ inflammation, yet this phenotype is not transferable into wildtype mice by hematopoietic stem cell transfer. Recent evidence demonstrated that Cpdm mice additionally display low bone mass, but the cellular and molecular causes of this phenotype remained to be established. Here we have applied non-decalcified histology together with cellular and dynamic histomorphometry to perform a thorough skeletal phenotyping of Cpdm mice. We show that Cpdm mice display trabecular and cortical osteopenia, solely explained by impaired bone formation, whereas osteoclastogenesis is unaffected. We additionally found that Cpdm mice display a severe disturbance of articular cartilage integrity in the absence of joint inflammation, supporting the concept that Sharpin-deficiency affects mesenchymal cell differentiation. Consistently, Cpdm mesenchymal cells displayed reduced osteogenic capacitiy ex vivo, yet this defect was not associated with impaired NF-κB signaling. A molecular comparison of wildtype and Cpdm bone marrow cell populations further revealed that Cpdm mesenchymal cells produce higher levels of Cxcl5 and lower levels of IL1ra. Collectively, our data demonstrate that skeletal defects of Cpdm mice are not caused by chronic inflammation, but that Sharpin is as a critical regulator of mesenchymal cell differentiation and gene expression. They additionally provide an alternative molecular explanation for the inflammatory phenotype of Cpdm mice and the absence of disease transfer by hematopoetic stem cell transplantation.
Project description:ATAC-seq profiling of Nfat5 KO and wild type macrophages derived from bone marrow (primary cells), treated or not with Lipopolysaccharide (LPS).
Project description:Our systems analysis reported here demonstrates that TLR-responses in macrophages are markedly impaired by SHARPIN deficiency, and that SHARPIN controls expression of a subset of TLR2-induced, NF-kB and AP-1 dependent genes that overlaps with those affected by the hypomorphic panr2 mutation in NEMO. 46 total RNA samples from murine bone marrow derived macrophages were analyzed (32 by Agilent array, 14 by Affymetrix Exon array) On Affymetrix Exon array, the responses of macrophages to 12hr stimulation with the TLR2 ligand PAM3CSK4 (300ng/mL) were analyzed in biological duplicates for the Map3k8(sluggish) mutant and respective controls and in singlet for the Tnf(KO) mutant compared to two respective WT controls.
Project description:Pathological processes like osteoporosis or steroid-induced osteonecrosis of the hip are accompanied by increased bone marrow adipogenesis. Such disorder of adipogenic/osteogenic differentiation, which affects also bone marrow derived mesenchymal stem cells (BMSCs) contributes to bone loss during aging. Therefore, we investigated the effects of extracellular vesicles (EVs) isolated from human (h)BMSCs during different stages of osteogenic differentiation on osteogenic and adipogenic differentiation capacity of naïve hBMSCs.
Project description:Introgressed variants from other species can be an important source of genetic variation because they may arise rapidly, can include multiple mutations on a single haplotype, and have often been pretested by selection in the species of origin. Although introgressed alleles are generally deleterious, several studies have reported introgression as the source of adaptive alleles-including the rodenticide-resistant variant of Vkorc1 that introgressed from Mus spretus into European populations of Mus musculus domesticus. Here, we conducted bidirectional genome scans to characterize introgressed regions into one wild population of M. spretus from Spain and three wild populations of M. m. domesticus from France, Germany, and Iran. Despite the fact that these species show considerable intrinsic postzygotic reproductive isolation, introgression was observed in all individuals, including in the M. musculus reference genome (GRCm38). Mus spretus individuals had a greater proportion of introgression compared with M. m. domesticus, and within M. m. domesticus, the proportion of introgression decreased with geographic distance from the area of sympatry. Introgression was observed on all autosomes for both species, but not on the X-chromosome in M. m. domesticus, consistent with known X-linked hybrid sterility and inviability genes that have been mapped to the M. spretus X-chromosome. Tract lengths were generally short with a few outliers of up to 2.7 Mb. Interestingly, the longest introgressed tracts were in olfactory receptor regions, and introgressed tracts were significantly enriched for olfactory receptor genes in both species, suggesting that introgression may be a source of functional novelty even between species with high barriers to gene flow.
Project description:Aged hematopoietic stem cells (HSCs) display myeloid-biased differentiation and reduced regenerative potential. In this study, we uncover that P-selectin (Selp) marks a subset of aged HSCs with reduced repopulation capacity. This population of HSCs expresses a prominent aging transcriptome. Overexpression of Selp in young HSCs impaired long-term reconstitution potential and repressed erythropoiesis. We show that IL-1β is elevated in aged bone marrow and administration of IL-1β induces expression of Selp and other aging-associated genes in HSCs. Finally, we demonstrate that transplantation of aged HSCs into young recipients restores a young-like transcriptome, specifically by repressing pro-inflammatory pathways, highlighting the important role of the bone marrow microenvironment in HSC aging.