Project description:Nfatc1 short isoform-specific KO mice are embryonic lethal. This isoform is essential for osteoclast differentiation and is responsible for the gene expression of various osteoclast markers, including the isoform itself. We used clariom s assay to explore genes showing altered expresssion during osteoclast differentiation in cultured hematopoietic progenitor cells from KO mice.
Project description:Cullin proteins are scaffolds that coordinate assembly of cullin-RING E3 ubiquitin (Ub) ligases (CRL), complexes that control post-translational ubiquitin modification and degradation of cellular proteins. Cullin-5 (Cul5) coordinates assembly of CRL complexes containing the RING E3 ligase Rbx1/2, the adapter proteins Elongins B and C, and a Suppressor of Cytokine Signalling (SOCS) box-containing substrate recognition protein. To explore potential roles for Cul5, we generated mice lacking Cul5 in the in hematopoietic system. Analyses included biological and molecular studies including proteomic analysis of differential expression of proteins in primary purified hematopoietic stem/progenitor (LSK) cells lacking Cul5.
Project description:The formation of hematopoietic cells relies on the chromatin remodeling activities of ISWI ATPase SMARCA5 (SNF2H) and its complexes. The Smarca5 null and conditional alleles have been used to study its functions in embryonic and organ development in mice. These mouse model phenotypes vary from embryonic lethality of constitutive knockout to less severe phenotypes observed in tissue-specific Smarca5 deletions, e.g., in the hematopoietic system. Here we show that, in a gene dosage-dependent manner, the hypomorphic allele of SMARCA5 (S5tg) can rescue not only the developmental arrest in hematopoiesis in the hCD2iCre model but also the lethal phenotypes associated with constitutive Smarca5 deletion or Vav1iCre-driven conditional knockout in hematopoietic progenitor cells. Interestingly, the latter model also provided evidence for the role of SMARCA5 expression level in hematopoietic stem cells, as the Vav1iCre S5tg animals accumulate stem and progenitor cells. Furthermore, their hematopoietic stem cells exhibited impaired lymphoid lineage entry and differentiation. This observation contrasts with the myeloid lineage which is developing without significant disturbances. Our findings indicate that animals with low expression of SMARCA5 exhibit normal embryonic development with altered lymphoid entry within the hematopoietic stem cell compartment.
Project description:Fus is the gene for a member of the FET family of RNA-binding proteins often involved in chromosomal translocations to generate oncogenic fusion genes in human cancers. Fus participates in multiple cellular functions, including RNA processing and transport, transcriptional regulation, and genome integrity. We uncovered its critical role in the maintenance of hematopoietic stem cells (HSCs). Fus-/- fetal livers developed normally except for a mild reduction in numbers of colony-forming cells compared to the wild type. The proliferation and differentiation of Fus-/- hematopoietic progenitors were normal in vitro. However, the number of colony-forming cells present in long-term cocultures of Fus-/- hematopoietic progenitors and stromal cells was significantly reduced. Fus-/- HSCs had an impaired long-term repopulating capacity and failed to repopulate in tertiary recipient mice. Fus-/- HSCs were highly susceptible to radiation both in vitro and in vivo and showed retardation of radiation-induced DNA damage repair. These findings define Fus as a novel regulator of HSCs and implicate it in stress-resistance and maintenance of the genomic integrity of HSCs. Therefore, it would be of importance to analyze the gene expression profiles of Fus-knockout hematopoietic stem/progenitor cells to understand its role in HSCs. Purified wild-type and Fus–/– KSL cells from BM of recipient mice repopulated with wild-type and Fus–/– fetal liver cells were subjected to RNA extraction and hybridization on Affymetrix microarrays. Data were obtained from dublicate samples.