ABSTRACTHuman placenta-derived mononuclear cells (MNC) were isolated by a Percoll density gradient and cultured in mesen-chymal stem cell (MSC) maintenance medium. The homogenous layer of adherent cells exhibited a ty...ABSTRACTHuman placenta-derived mononuclear cells (MNC) were isolated by a Percoll density gradient and cultured in mesen-chymal stem cell (MSC) maintenance medium. The homogenous layer of adherent cells exhibited a typical fibroblast-like morphology, a large expansive potential, and cell cycle characteristics including a subset of quiescent cells. In vitrodifferentiation assays showed the tripotential differentiation capacity of these cells toward adipogenic, osteogenic andchondrogenic lineages. Flow cytometry analyses and immunocytochemistry stain showed that placental MSC was ahomogeneous cell population devoid of hematopoietic cells, which uniformly expressed CD29, CD44, CD73, CD105,CD166, laminin, fibronectin and vimentin while being negative for expression of CD31, CD34, CD45 and α-smoothmuscle actin. Most importantly, immuno-phenotypic analyses demonstrated that these cells expressed class I majorhistocompatibility complex (MHC-I), but they did not express MHC-II molecules. Additionally these cells could sup-press umbilical cord blood (UCB) lymphocytes proliferation induced by cellular or nonspecific mitogenic stimuli. Thisstrongly implies that they may have potential application in allograft transplantation. Since placenta and UCB arehomogeneous, the MSC derived from human placenta can be transplanted combined with hematopoietic stem cells(HSC) from UCB to reduce the potential graft -versus-host disease (GVHD) in recipients.展开更多
This study was designed using c-myc antisense transcripts to evaluate how alteration of c-myc expression in human myeloid leukemic HL-60 cells could influence the myelomonocytic differentiation and induction of apopto...This study was designed using c-myc antisense transcripts to evaluate how alteration of c-myc expression in human myeloid leukemic HL-60 cells could influence the myelomonocytic differentiation and induction of apoptosis. The recombinant plasmid pDACx expressing antisense transcripts to c-myc fragment containing a part of intron 1 and 137 nt exon 2 was constructed. pDACx was transfected into HL-60 cell line by lipofectin reagent.Cytochemical stainings including NBT reduction, peroxidase and α -NAE as well as detection of CD13 and CD33 antigens by flow cytometric analysis indicated occurrence of myelomonocytic differentiation in cells expressing antisense transcripts to c-myc. DNA degradation measured by DNA gel electrophoresis and typical morphological changes observed under electron microscope proved the switchon of apoptosis in terminally differentiating HL-60 cells.展开更多
基金This study was supported by a grant from National Natural Science Foundation of China(No.30271245)Hi-Tech Research and Development Program of China(863 Program)(No.2003AA205170)+1 种基金National Basic Research Program of China(973 Program)(No.G 1999054302)a grant from Bejing Gynecology and Obstetrics Hospital Affiliate of Capital University of Medical Sciences.
文摘ABSTRACTHuman placenta-derived mononuclear cells (MNC) were isolated by a Percoll density gradient and cultured in mesen-chymal stem cell (MSC) maintenance medium. The homogenous layer of adherent cells exhibited a typical fibroblast-like morphology, a large expansive potential, and cell cycle characteristics including a subset of quiescent cells. In vitrodifferentiation assays showed the tripotential differentiation capacity of these cells toward adipogenic, osteogenic andchondrogenic lineages. Flow cytometry analyses and immunocytochemistry stain showed that placental MSC was ahomogeneous cell population devoid of hematopoietic cells, which uniformly expressed CD29, CD44, CD73, CD105,CD166, laminin, fibronectin and vimentin while being negative for expression of CD31, CD34, CD45 and α-smoothmuscle actin. Most importantly, immuno-phenotypic analyses demonstrated that these cells expressed class I majorhistocompatibility complex (MHC-I), but they did not express MHC-II molecules. Additionally these cells could sup-press umbilical cord blood (UCB) lymphocytes proliferation induced by cellular or nonspecific mitogenic stimuli. Thisstrongly implies that they may have potential application in allograft transplantation. Since placenta and UCB arehomogeneous, the MSC derived from human placenta can be transplanted combined with hematopoietic stem cells(HSC) from UCB to reduce the potential graft -versus-host disease (GVHD) in recipients.
文摘This study was designed using c-myc antisense transcripts to evaluate how alteration of c-myc expression in human myeloid leukemic HL-60 cells could influence the myelomonocytic differentiation and induction of apoptosis. The recombinant plasmid pDACx expressing antisense transcripts to c-myc fragment containing a part of intron 1 and 137 nt exon 2 was constructed. pDACx was transfected into HL-60 cell line by lipofectin reagent.Cytochemical stainings including NBT reduction, peroxidase and α -NAE as well as detection of CD13 and CD33 antigens by flow cytometric analysis indicated occurrence of myelomonocytic differentiation in cells expressing antisense transcripts to c-myc. DNA degradation measured by DNA gel electrophoresis and typical morphological changes observed under electron microscope proved the switchon of apoptosis in terminally differentiating HL-60 cells.
