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c-Kit Receptor (c-kit + receptor)
Selected AbstractsC-Kit receptor (CD117) expression on myeloblasts and white blood cell counts in acute myeloid leukemiaCYTOMETRY, Issue 1 2004Jolanta Wo Abstract Background The c-Kit receptor is considered to play a crucial role in hematopoiesis. Induction of mobilization of hematopoietic cells in the bone marrow requires cooperative signaling through c-Kit and c-Kit ligand pathway, and these interactions are important in the retention of stem cells within the bone marrow. Therefore, we analyzed c-Kit density on the leukemic myeloblasts of patients with acute myeloid leukemia (AML) in relation to white blood cell count (WBC) in the peripheral blood. Methods Bone marrow aspirates collected from patients with AML and bone marrow aspirates and leukapheresis products after granulocyte colony-stimulating factor blood mobilization from adult volunteers were studied. To determine the level of c-Kit receptor expression, we applied quantitative (relative fluorescence intensity and antibody binding per cell) cytometric methods. Results Our data showed negative correlation between the level of c-Kit expression intensity on myeloblasts and the number of leukocytes in blood of AML patients. The c-Kit receptor density on myeloblasts in patients with low WBC was significantly stronger than that on myeloblasts in patients with high WBC. In the latter patient group, the density c-Kit receptor on myeloblasts was similar to that on CD34+ cells in mobilized peripheral blood. Conclusions The obtained data suggest an involvement of c-Kit receptor in the regulation of leukemic myeloblasts egress to the peripheral blood. © 2004 Wiley-Liss, Inc. [source] Bone morphogenetic protein 4 modulates c-Kit expression and differentiation potential in murine embryonic aorta-gonad-mesonephros haematopoiesis in vitroBRITISH JOURNAL OF HAEMATOLOGY, Issue 2 2007Caroline J. Marshall Summary The transforming growth factor- , -related factor bone morphogenetic protein 4 (BMP4) is expressed in the human embryonic aorta-gonad-mesonephros (AGM) coincident with the emergence of haematopoietic cells and influences postnatal mammalian haematopoietic stem cells in vitro. To investigate the role of BMP4 in mammalian embryonic haematopoiesis, cells were isolated from murine AGM and two populations of CD34+ cells with different levels of c-Kit expression and multipotency were identified. CD34+/c-Kithigh cells express CD45 and are haematopoietic-restricted progenitors. In contrast, CD34+/c-Kitlow cells are Flk1+/CD45neg and generate adherent colonies in ex vivo culture that resemble haemangioblast colonies identified in other systems. The addition of BMP4 to AGM cells resulted in expansion of the CD34+/c-Kitlow cell pool within 48 h, via a combination of down modulation of the c-Kit receptor in CD34+/c-Kithigh cells and proliferation. In long-term culture, BMP4 increased the growth/survival of CD34+/c-Kithigh haematopoietic progenitors, effects that were blocked by BMP inhibitors. CD34+/c-Kithigh progenitors cultured with BMP4 also generated adherent colonies typical of c-Kitlow cells. These results suggest that BMP4 regulates c-Kit expression and differentiation potential in CD34+ AGM cells and supports a role for BMP signalling in the maintenance of multipotency during embryonic haematopoiesis, providing an insight into stem cell homeostasis within the mammalian haematopoietic niche. [source] Adhesion molecule expression by bone marrow CD34-positive cells in aplastic anemia before and after immunosuppressive therapyINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 6 2003K. Kaito Summary Appropriate adhesion between bone marrow stem cells and the marrow microenvironment is necessary for hematopoiesis, since signals that promote maturation or apoptosis are transmitted from stromal cells to stem cells. In aplastic anemia (AA), interferon- , produced by stromal cells has more influence on the pathogenesis of marrow failure than interferon- , produced by lymphocytes. We evaluated the expression of cell adhesion molecules, such as very late antigen-4 (CD49d), and -5 (CD49e) or c-kit receptor (CD117), by CD34-positive bone marrow cells in patients with AA who achieved hematological complete remission after immunosuppressive therapy. Before treatment, CD34-positive cells showed markedly higher expression of CD49d and CD49e than cells from healthy controls, indicating the strong adhesion of stem cells to the bone marrow stroma. Expression of CD49d and CD49e was significantly decreased, reaching normal levels, after hematological recovery. These findings suggest that changes in adhesion molecule expression by stem cells are important in the pathology of AA. [source] Effects of imatinib mesylate (Glivec®) as a c-kit tyrosine kinase inhibitor in the guinea-pig urinary bladderNEUROUROLOGY AND URODYNAMICS, Issue 3 2006Yasue Kubota Abstract Aims In the gastrointestinal tract, slow wave activity in smooth muscle is generated by the interstitial cells of Cajal (ICC). Detrusor smooth muscle strips of most species show spontaneous contractions which are triggered by action potential bursts, however, the pacemaker mechanisms for the detrusor are still unknown. Recently, ICC-like cells have been found in guinea-pig bladder, using antibodies to the c-kit receptor. We have investigated the effects of Glivec, a c-kit tyrosine kinase inhibitor, on spontaneous action potentials in guinea-pig detrusor and intravesical pressure of isolated guinea-pig bladders. Methods Changes in the membrane potential were measured in guinea-pig detrusor smooth muscle using conventional microelectrode techniques. Pressure changes in the bladder were recorded using whole organ bath techniques. Results Smooth muscle cells in detrusor muscle bundles exhibited spontaneous action potentials, and spontaneous pressure rises occurred in isolated bladders. Glivec (10 ,M) converted action potential bursts into continuous firing with no effects on the shape of individual action potentials. Glivec (>50 ,M) reduced the amplitude of spontaneous pressure rises in the whole bladder in a dose dependent manner and abolished spontaneous action potentials in detrusor smooth muscle cells. Conclusions The results suggest that ICC-like cells may be responsible for generating bursts of action potentials and contractions in detrusor smooth muscle. Drugs inhibiting the c-kit receptor may prove useful for treating the overactive bladder. Neurourol. Urodynam. © 2006 Wiley-Liss, Inc. [source] Growth suppression of human mast cells expressing constitutively active c-kit receptors by JNK inhibitor SP600125GENES TO CELLS, Issue 9 2006Bin Wang First page of article [source] Solitary mastocytoma occurring at a site of traumaAUSTRALASIAN JOURNAL OF DERMATOLOGY, Issue 2 2009Alana Jane Tuxen ABSTRACT We describe a patient with a solitary mastocytoma arising at a site of trauma. The patient was born with the umbilical cord wrapped around her right thigh and subsequently developed a solitary mastocytoma in the exact site and distribution of this injury. The pathogenesis of mast cell proliferation in solitary mastocytoma is not completely understood. Cytokines released after injury, such as stem cell factor, may stimulate the proliferation of mast cells, as well as fibroblasts and melanocytes to form a mastocytoma. Mast cells in a newborn may be more sensitive to stem cell factor in the presence of cytokines released after injury due to an increased density of c-kit receptors. We present our patient and review the literature to support a hypothesis that this condition represents a reactive, and not neoplastic, process. [source] | |||||||||||||