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BM Stromal Cells (bm + stromal_cell)
Selected AbstractsHaematopoietic progenitor cells from the common marmoset as targets of gene transduction by retroviral and adenoviral vectorsEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 4 2001Hitoshi Hibino Abstract: To establish a new non-human primate model for human cytokine and gene therapy, we characterized lymphocytes and haematopoietic progenitor cells of the small New World monkey, the common marmoset. We first assessed the reactions of marmoset bone marrow (BM) and peripheral blood (PB) cells to mouse anti-human monoclonal antibodies (mAbs) for the purpose of isolating marmoset lymphocytes and haematopoietic progenitor cells. Both cell fractions stained with CD4 and CD8 mAbs were identified as lymphocytes by cell proliferation assay and morphological examination. Myeloid-specific mAbs such as CD14 and CD33 did not react with marmoset BM and PB cells. No available CD34 and c-kit mAbs could be used to purify the marmoset haematopoietic progenitor cells. Furthermore, we studied the in vitro transduction of the bacterial ,-galactosidase (LacZ) gene into CFU-GM derived from marmoset BM using retroviral and adenoviral vectors. The transduction efficiency was increased by using a mixed culture system consisting of marmoset BM stromal cells and retroviral producer cells. It was also possible to transduce LacZ gene into marmoset haematopoietic progenitor cells with adenoviral vectors as well as retroviral vectors. The percentage of adenovirally transduced LacZ-positive clusters was 15% at day 4 (multiplicity of infection=200), but only 1,2% at day 14. The differential use of viral vector systems is to be recommended in targeting different diseases. Our results suggested that marmoset BM progenitor cells were available to examine the transduction efficiency of various viral vectors in vitro. [source] Microenvironmental influences on human B-cell developmentIMMUNOLOGICAL REVIEWS, Issue 1 2000F. E. Bertrand Summary: Mammalian B-cell development can be viewed as a developmental performance with several acts. The acts are represented by checkpoints centered around commitment to the B-lineage and functional Ig gene rearrangement , culminating in expression of the pre-B-cell receptor (pre-BCR) and the BCR. Progression of cells through these checkpoints is profoundly influenced by the fetal liver and adult bone marrow (BM) stromal cell microenvironments. Our laboratory has developed a model of human B-cell development that utilizes freshly isolated/non-transformed human BM stromal cells as an in vitro microenvironment. Human CD34+ hematopoietic stem cells plated in this human BM stromal cell microenvironment commit to the B lineage and progress through the pre-BCR and BCR checkpoints. This human BM stromal cell microenvironment also provides survival signals that prevent apoptosis in human B-lineage cells. Human B-lineage cells exhibit differential expression of Notch receptors and human BM stromal cells express the Notch ligand Jagged-1. These results suggest a potential role for Notch in regulating B-lineage commitment and/or progression through the pre-BCR and BCR checkpoints. [source] Regulation of global gene expression in the bone marrow microenvironment by androgen: Androgen ablation increases insulin-like growth factor binding protein-5 expressionTHE PROSTATE, Issue 15 2007Chang Xu Abstract BACKGROUND Prostate cancer frequently metastasizes to bone. Androgen suppression treatment is initially highly effective, but eventually results in resistant cancer cells. This study evaluates the effects of androgen suppression on the bone and bone marrow (BM). In particular we questioned whether the androgen therapy could adversely facilitate prostate cancer progression through an increase growth factor secretion by the bone microenvironment. METHODS Global gene expression is analyzed on mPEDB DNA microarrays. Insulin-like growth factor binding protein-5 (IGFBP5) is detected by immunohistochemistry in mouse tissues and its regulation measured by qPCR and Western blotting in human BM stromal cells. Effects of extracellular matrix-associated IGFBP5 on human prostate epithelial cells are tested in an MTS cell-growth assay. RESULTS Castration increases expression of 159 genes (including 4 secreted cytokines) and suppresses expression of 84 genes. IGFBP5 is most consistently increased and the increase in expression is reversed by testosterone administration. IGFBP5 protein is detected in vivo in osteoblasts, BM stromal cells, and endothelial cells. Primary human stromal cell cultures secrete IGFBP5. In vitro, treatment of immortalized human marrow stromal cells with charcoal-stripped serum increases IGFBP5 mRNA expression, which is reversed by androgen supplementation. IGFBP5 is incorporated into the extracellular matrix. Further, IGFBP5 immobilized on extracellular matrices of stromal cells enhances the growth of immortalized prostate epithelial cells. CONCLUSIONS Androgen suppressive therapy increases IGFBP5 in the BM microenvironment and thereby may facilitate the progression of prostate cancer. Prostate 67: 1621,1629, 2007. © 2007 Wiley-Liss, Inc. [source] Increased expression of CD40 on bone marrow CD34+ hematopoietic progenitor cells in patients with systemic lupus erythematosus: Contribution to Fas-mediated apoptosisARTHRITIS & RHEUMATISM, Issue 2 2009Katerina Pyrovolaki Objective Patients with systemic lupus erythematosus (SLE) display increased apoptosis of bone marrow (BM) CD34+ hematopoietic progenitor cells. This study was undertaken to evaluate the expression of CD40 and CD40L in the BM of SLE patients, and to explore the possible involvement of these molecules in apoptosis of CD34+ cells. Methods The proportion and survival characteristics of CD40+ cells within the BM CD34+ fraction from SLE patients and healthy controls were evaluated by flow cytometry. The production of CD40L by BM stromal cells was assessed using long-term BM cultures, and the effect of CD40L on the survival characteristics and clonogenic potential of CD34+ cells was evaluated ex vivo by flow cytometry and clonogenic assays. Results SLE patients displayed an increased proportion of CD40+ cells within the CD34+ fraction as compared with controls. The CD34+CD40+ subpopulation contained an increased proportion of apoptotic cells compared with the CD34+CD40, fraction in patients and controls, suggesting that CD40 is involved in the apoptosis of CD34+ cells. Stimulation of patients' CD34+ cells with CD40L increased the proportion of apoptotic cells and decreased the proportion of colony-forming cells as compared with untreated cultures. The CD40L-mediated effects were amplified following treatment with recombinant Fas ligand, suggesting that the effects of these ligands are synergistic. CD40L levels were significantly increased in long-term BM culture supernatants and adherent layers of BM cells from SLE patients as compared with controls. Conclusion These data reveal a novel role for the CD40/CD40L dyad in SLE by demonstrating that up-regulation and induction of CD40 on BM CD34+ cells from patients with SLE contribute to the amplification of Fas-mediated apoptosis of progenitor cells. [source] Gene expression of anti- and pro-apoptotic proteins in malignant and normal plasma cellsBRITISH JOURNAL OF HAEMATOLOGY, Issue 1 2009Michel Jourdan Summary The survival of malignant plasma cells is a key event in disease occurrence, progression and chemoresistance. Using DNA-microarrays, we analysed the expression of genes coding for 58 proteins linked with extrinsic and intrinsic apoptotic pathways, caspases and inhibitor of apoptosis proteins. We considered six memory B cells (MBC), seven plasmablasts (PPC), seven bone marrow plasma cells (BMPC) and purified myeloma cells (MMC) from 92 newly-diagnosed patients. Forty out of the 58 probe sets enabled the separation of MBC, PPC and BMPC in three homogeneous clusters, characterized by an elevated expression of TNFRSF10A, TNFRSF10B, BCL2A1, CASP8, CASP9 and PMAIP1 genes for MBC, of FAS, FADD, AIFM1, BIRC5, CASP CASP2, CASP3 and CASP6 for PPC and of BCL2, MCL1, BID, BIRC3 and XIAP for BMPC. Thus, B cell differentiation was associated with change of expression of pro-apoptotic and anti-apoptotic genes. Regarding MMC, the major finding was TRAIL upregulation that might be counteracted by a high osteoprotegerin production by BM stromal cells and a decreased expression of FAS, APAF1 and BNIP3 compared to normal BMPC. Out of the 40 genes, CASP2 and BIRC5 expression in MMC had adverse prognosis in two independent series of previously-untreated patients. [source] Inhibition of Akt induces significant downregulation of survivin and cytotoxicity in human multiple myeloma cellsBRITISH JOURNAL OF HAEMATOLOGY, Issue 6 2007Teru Hideshima Summary Akt mediates growth and drug resistance in multiple myeloma (MM) cells in the bone marrow (BM) microenvironment. We have shown that a novel Akt inhibitor Perifosine induces significant cytotoxicity in MM cells in the BM milieu. This study further delineated molecular mechanisms whereby Perifosine triggered cytotoxicity in MM cells. Neither the intensity of Jun NH2 -terminal kinase phosphorylation nor caspase/poly (ADP-ribose) polymerase cleavage correlated with Perifosine-induced cytotoxicity in MM.1S, INA6, OPM1 and OPM2 MM cells. However, survivin, which regulates caspase-3 activity, was markedly downregulated by Perifosine treatment, without changes in other anti-apoptotic proteins. Downregulation of survivin by siRNA significantly inhibited OPM1 MM cell growth, confirming that survivin mediates MM cell survival. Perifosine significantly downregulated both function and protein expression of ,-catenin. Co-culture with BM stromal cells (BMSCs) upregulated both ,-catenin and survivin expression in MM cells, which was blocked by Perifosine. Importantly, Perifosine treatment also downregulated survivin expression in human MM cells grown in vivo in a severe combined immunodeficient mouse xenograft model. Finally, Perifosine inhibited bortezomib-induced upregulation of survivin, associated with enhanced cytotoxicity of combined bortezomib and Perifosine treatment. These preclinical studies provide the framework for clinical trials of bortezomib with Perifosine to improve patient outcome in MM. [source] Human thymic epithelial cells maintain long-term survival of clonogenic myeloid and erythroid progenitor cells in vitroBRITISH JOURNAL OF HAEMATOLOGY, Issue 1 2000Katsuto Takenaka Precursor cells that migrate into the thymus are still multipotent. Therefore, thymic epithelial cells (TECs) may provide microenvironments not only for T-cell development, but also for maintenance of multipotent precursor cells until they undergo T-cell commitment. In the present study, we performed long-term cultures of CD34+ bone-marrow (BM) cells on TEC lines that were derived from cortical epithelial cells of post-natal thymus, to investigate whether human TECs could maintain long-term non-lymphoid haematopoiesis. Haematopoietic cells maintained in direct contact with established TEC lines were able to generate clonogenic progeny to both myeloid and erythroid cells for periods in excess of 5 weeks. Their abilities to support colony-forming units of granulocytes,macrophages (CFU-GM) and burst-forming units of erythroids (BFU-E) were almost equal to those of BM stromal cells. We observed similar results by using cloned TEC lines derived by limiting dilution, as well as those by using parental TEC lines. Colony-forming activities were maintained even when haematopoietic progenitor cells were physically separated from TEC lines and cultured on microporous membrane. These observations indicate that haematopoiesis maintained in TEC-contact long-term cultures may depend on soluble factors produced by TEC lines. Our results suggest that thymic cortical epithelial cells have the ability to support not only the differentiation of haematopoietic cells, but also long-term survival of clonogenic myeloid/erythroid progenitor cells. [source] | ||||||||||