Project description:Human bone marrow stromal cells (BMSCs) are key elements of the hematopoietic environment and they play a central role in bone and bone marrow physiology. However, how key BMSC functions are regulated is largely unknown. We analyzed the role of the immediate early response transcription factor EGR1 as key BMSC regulator and found that EGR1 was highly expressed in prospectively-isolated primary BMSCs, downregulated upon culture, and lower in non-CFU-F-containing CD45neg BM cells. Furthermore, EGR1 expression was lower in proliferative regenerating adult and fetal primary cells compared to adult steady-state BMSCs. Accordingly, EGR1 overexpression markedly decreased BMSC proliferation but considerably improved hematopoietic stroma support function as indicated by an increased production of transplantable CD34+CD90+ hematopoietic stem cells in expansion co-cultures. The improvement of BMSC stroma support function was mediated by increased expression of hematopoietic supporting genes, such as VCAM1 and CCL28. On the other hand, EGR1 knockdown increased ROS-mediated BMSC proliferation, and clearly reduced BMSC hematopoietic stroma support potential. These findings thus show that EGR1 is a key BMSC transcription factor with a dual role in regulating proliferation and hematopoietic stroma support function that is controlling a genetic program to coordinate the specific functions of BMSC in their different biological contexts.
Project description:We found that the bone marrow microenvironment of Crebbp+/- mice was unable to properly maintain the immature stem - and progenitor pools. Instead, it stimulates myeloid differentiation that progresses into a myeloproliferative-like disease. Since CREBBP is a transcriptional co-activator, we used gene expression analysis to globally assess functional deficiencies in Crebbp+/- bone marrow stroma cells at a molecular level. Ep300 encodes a protein which is highly similar in structure and function to CREBBP; nevertheless, Ep300+/- mice suffer neither excessive myeloid differentiation nor loss of HSCs. Therefore, to identify expression changes specifically related to Crebbp heterozygosity, we focused on genes that showed significant differences in expression levels between Crebbp+/- and wild-type bone marrow stroma but no difference between Ep300+/- and wild-type. Bone marrow stroma was established from wild-type, Crebbp+/- and Ep300+/- mice that were 3-4 months old for RNA extraction and hybridization on Affymetrix microarrays. There are 4 biological replicates for each genotype used.
Project description:We found that the bone marrow microenvironment of Crebbp+/- mice was unable to properly maintain the immature stem - and progenitor pools. Instead, it stimulates myeloid differentiation that progresses into a myeloproliferative-like disease. Since CREBBP is a transcriptional co-activator, we used gene expression analysis to globally assess functional deficiencies in Crebbp+/- bone marrow stroma cells at a molecular level. Ep300 encodes a protein which is highly similar in structure and function to CREBBP; nevertheless, Ep300+/- mice suffer neither excessive myeloid differentiation nor loss of HSCs. Therefore, to identify expression changes specifically related to Crebbp heterozygosity, we focused on genes that showed significant differences in expression levels between Crebbp+/- and wild-type bone marrow stroma but no difference between Ep300+/- and wild-type.
Project description:The transcriptome changes of breast cancer cell SUM1315, with or without co-culture with bone marrow stroma cells, upon cisplatin (CDDP) treatment.
Project description:Gene expression profiling by cDNA microarray of bone marrow stromal cells from three healthy donors treated as follows: vehicle control; or stimulated with 10 nM substance P. Hematopoiesis is tightly regulated by the bone marrow (BM) niche. The niche is robust, allowing for the return of hematopoietic homeostasis after insults such as infection. Hematopoiesis is partly regulated by soluble factors such as neuropeptides, substance P (SP) and neurokinin A (NK-A), which mediate hematopoietic stimulation and inhibition, respectively. The hematopoietic effects of SP and NK-A are mostly mediated via BM stroma. Array analyses with 2400 genes indicated distinct changes in SP-stimulated BM stroma.