{"owner": "ArrayExpress Uploader", "pop_total": 0, "id": 7941, "factors": [{"GSE9188GSM232046": {}}, {"GSE9188GSM232047": {}}, {"GSE9188GSM232048": {}}, {"GSE9188GSM232049": {}}, {"GSE9188GSM232050": {}}], "ownerprofile_id": "arrayexpress_sid", "platform": 6, "summary_wrapped": "Self-renewal is a defining characteristic of stem cells, however the molecular pathways underlying its regulation are poorly understood....", "pubmed_id": 18462698, "geo_gse_id": "E-GEOD-9188", "owner_profile": "/profile/8773/arrayexpressuploader", "factor_count": 0, "sample_count": 5, "tags": ["bone", "bone marrow", "cell", "compartment", "stem cell"], "lastmodified": "Dec.12, 2014", "is_default": false, "geo_gds_id": "", "slug": "transcription-profiling-of-mouse-long-term-hsc-fro", "geo_id_plat": "E-GEOD-9188_A-AFFY-45", "name": "Transcription profiling of mouse long term HSC from control or Pbx1-null mice", "created": "Nov.18, 2014", "summary": "Self-renewal is a defining characteristic of stem cells, however the molecular pathways underlying its regulation are poorly understood.  Here we demonstrate that conditional inactivation of the Pbx1 proto-oncogene in the hematopoietic compartment results in a progressive loss of long-term hematopoietic stem cells (LT-HSCs) that is associated with concomitant reduction in their quiescence, leading to a defect in the maintenance of self-renewal as assessed by serial transplantation.  Transcriptional profiling revealed that multiple stem cell maintenance factors are perturbed in Pbx1-deficient LT-HSCs, which prematurely express a large subset of genes, including cell cycle regulators, normally expressed in non-self-renewing multipotent progenitors.  A significant proportion of Pbx1-dependent genes are associated with the Tgf-b pathway, which serves a major role in maintaining HSC quiescence.  Pbx1-deficient LT-HSCs are unable to up-regulate the cyclin dependent kinase inhibitor p57 in response to Tgf-b, providing a mechanism through which Pbx1 maintenance of stem cell self-renewal is achieved.  Experiment Overall Design: Highly efficient Pbx1 deletion was induced with poly(I:C) in 3 young MxCre+.Pbx1f/f mutant or 2 MxCre-.Pbx1f/f control mice. LT-HSC (Lin-cKit+Sca1+CD34-CD135-) cells were prospectively sorted from bone marrow of individual mice harvested 4 weeks after the last injection of poly(I:C).", "source": "http://www.ebi.ac.uk/arrayexpress/experiments/E-GEOD-9188", "species": "mouse", "sample_source": "http://www.ebi.ac.uk/arrayexpress/experiments/E-GEOD-9188/samples/"}