To clarify the hematopoietic potential of various sub-classes of human hematopoietic progenitor cells, we used a multicolor staining protocol in conjunction with anti-CD34 and -CD38 McAb. We characterized two cell fra...To clarify the hematopoietic potential of various sub-classes of human hematopoietic progenitor cells, we used a multicolor staining protocol in conjunction with anti-CD34 and -CD38 McAb. We characterized two cell fractions in CD34+cells with or without CD38 expression. A clonogenic assay showed that most CFC were present in CD34+CD38+ population. Morphologic analysis showed that blast-like cells were more enriched in the CD34+CD38 fraction. To clarify the biologic differences between both fractions, we examined the more primitive progenitor cell function by assessing long-term culture-initiating cells (LTC-IC) on the stromal cells. At the first two weeks, more CF.C harvested from the culture in the fractions initiated with both populations. However, more LTC-IC were present during weeks 4 to 12 in the CD34+CD38- population. These results indicate the primitive progenitors are more enriched in CD34+CD38 population than in CD34+CD38+ cells.展开更多
Human adipose tissue obtained by liposuction is easily accessible and an abundant potential source of autologous cells for regenerative medicine applications. After digestion of the tissue and removal of differentiate...Human adipose tissue obtained by liposuction is easily accessible and an abundant potential source of autologous cells for regenerative medicine applications. After digestion of the tissue and removal of differentiated adipocytes, the so-called stromal vascular fraction (SVF) of adipose, a mix of various cell types, is obtained. SVF contains mesenchymal fibroblastic cells, able to adhere to culture plastic and to generate large colonies in vitro , that closely resemble bone marrow-derived colony forming units-fibroblastic, and whose expanded progeny, adipose mesenchymal stem/stromal cells (ASC), show strong similarities with bone marrow mesenchymal stem cells. The sialomucin CD34, which is well known as a hematopoietic stem cell marker, is also expressed by ASC in native adipose tissue but its expression is gradually lost upon standard ASC expansion in vitro . Surprisingly little is known about the functional role of CD34 in the biology and tissue forming capacity of SVF cells and ASC. The present editorial provides a short introduction to the CD34 family of sialomucins and reviews the data from the literature concerning ex- pression and function of these proteins in SVF cells and their in vitro expanded progeny.展开更多
Circulating endothelial progenitor cells(EPCs) have been demonstrated to correlate negatively with vascularendothelial dysfunction and cardiovascular risk factors. However, translation of basic research into the clini...Circulating endothelial progenitor cells(EPCs) have been demonstrated to correlate negatively with vascularendothelial dysfunction and cardiovascular risk factors. However, translation of basic research into the clinical practice has been limited by the lack of unambiguous and consistent definitions of EPCs and reduced EPC cell number and function in subjects requiring them for clinical use. This article critically reviews the definition of EPCs based on commonly used protocols, their value as a biomarker of cardiovascular risk factor in subjects with cardiovascular disease, and strategies to enhance EPCs for treatment of ischemic diseases.展开更多
Summary： The characteristics for the ex vivo expansion of the endothelial progenitor cells （EPCs） were explored, CD34^＋ cells were selected from umbilical cord blood mononuclear cells （MNC） by MiniMACS system, e...Summary： The characteristics for the ex vivo expansion of the endothelial progenitor cells （EPCs） were explored, CD34^＋ cells were selected from umbilical cord blood mononuclear cells （MNC） by MiniMACS system, expanded under the same conditions as those for total MNC, coincubation of CD34^＋ and CD34 from the same donor for EPCs. In addition, the effects of vessel endothelial growth factor （VEGF） and passage on cell differentiation, expansion kinetics and apoptosis were examined, EPCs were determined and quantified by immunocytochemistry and flow cytometry, The results showed that both coculture of CD346＋ and CD34^- and total MNC led to a significant increase in the expansion of CD34^＋ cells as compared with CD34 enrichment （P〈0.05）. There was a tendency toward decreased apoptosis in cultures when early passage was performed immediately after cord like structures appeared. VEGF had no significant effect on apoptosis （P〉0.05）, These differentiated EPCs were positive for CD34^＋, von Willebrand factor （vWF）, KDR, CD31 staining and phagocytized acetylated low-density lipoprotein （LDL）. CD34^＋ cells accounted for （68.2±6,3） % of attaching （AT） cells at day 7 of culture. It was suggested the most efficient method to ex vivo expansion of EPCs was coculture of CD34^＋ and CD34^- or total MNC. Early passage makes cell apoptosis rate decrease. VEGF had no significant effect on ex vivo expansion of EPCs.展开更多
In this paper,experimental findings concerning the kinetics of hematopoietic reconstitution are compared to corresponding clinical data.Although not clearly apparent,the transplantation practice seems to confirm the b...In this paper,experimental findings concerning the kinetics of hematopoietic reconstitution are compared to corresponding clinical data.Although not clearly apparent,the transplantation practice seems to confirm the basic proposals of experimental hematology concerning hematopoietic reconstitution resulting from successive waves of repopulation stemming from different subpopulations of progenitor and stem cells.One of the "f irst rate" parameters in clinical transplantations in hematology;i.e.the CD34+ positive cell dose,has been discussed with respect to the functional heterogeneity and variability of cell populations endowed by expression of CD34.This parameter is useful only if the relative proportion of stem and progenitor cells in the CD34+ cell population is more or less maintained in a series of patients or donors.This proportion could vary with respect to the source,pathology,treatment,processing procedure,the graft ex vivo treatment and so on.Therefore,a universal dose of CD34+ cells cannot be def ined.In addition,to avoid further confusion,the CD34+ cells should not be named "stem cells" or "progenitor cells" since these denominations only concern functionally characterized cell entities.展开更多
文摘To clarify the hematopoietic potential of various sub-classes of human hematopoietic progenitor cells, we used a multicolor staining protocol in conjunction with anti-CD34 and -CD38 McAb. We characterized two cell fractions in CD34+cells with or without CD38 expression. A clonogenic assay showed that most CFC were present in CD34+CD38+ population. Morphologic analysis showed that blast-like cells were more enriched in the CD34+CD38 fraction. To clarify the biologic differences between both fractions, we examined the more primitive progenitor cell function by assessing long-term culture-initiating cells (LTC-IC) on the stromal cells. At the first two weeks, more CF.C harvested from the culture in the fractions initiated with both populations. However, more LTC-IC were present during weeks 4 to 12 in the CD34+CD38- population. These results indicate the primitive progenitors are more enriched in CD34+CD38 population than in CD34+CD38+ cells.
基金Supported by The Swiss National Science Foundation, SNF grants No. 310030-120432 and No. 310030-138519, to Scherberich Agrants from The AllerGen NCE, The Canadian Institutes for Health Research and The Heart and Stroke Foundation of BC and Yukon, to McNagny KM
文摘Human adipose tissue obtained by liposuction is easily accessible and an abundant potential source of autologous cells for regenerative medicine applications. After digestion of the tissue and removal of differentiated adipocytes, the so-called stromal vascular fraction (SVF) of adipose, a mix of various cell types, is obtained. SVF contains mesenchymal fibroblastic cells, able to adhere to culture plastic and to generate large colonies in vitro , that closely resemble bone marrow-derived colony forming units-fibroblastic, and whose expanded progeny, adipose mesenchymal stem/stromal cells (ASC), show strong similarities with bone marrow mesenchymal stem cells. The sialomucin CD34, which is well known as a hematopoietic stem cell marker, is also expressed by ASC in native adipose tissue but its expression is gradually lost upon standard ASC expansion in vitro . Surprisingly little is known about the functional role of CD34 in the biology and tissue forming capacity of SVF cells and ASC. The present editorial provides a short introduction to the CD34 family of sialomucins and reviews the data from the literature concerning ex- pression and function of these proteins in SVF cells and their in vitro expanded progeny.
文摘Circulating endothelial progenitor cells(EPCs) have been demonstrated to correlate negatively with vascularendothelial dysfunction and cardiovascular risk factors. However, translation of basic research into the clinical practice has been limited by the lack of unambiguous and consistent definitions of EPCs and reduced EPC cell number and function in subjects requiring them for clinical use. This article critically reviews the definition of EPCs based on commonly used protocols, their value as a biomarker of cardiovascular risk factor in subjects with cardiovascular disease, and strategies to enhance EPCs for treatment of ischemic diseases.
基金This project was supported by a grant from Hubei Provin-cial Bureau of Health (No. WI01532).
文摘Summary： The characteristics for the ex vivo expansion of the endothelial progenitor cells （EPCs） were explored, CD34^＋ cells were selected from umbilical cord blood mononuclear cells （MNC） by MiniMACS system, expanded under the same conditions as those for total MNC, coincubation of CD34^＋ and CD34 from the same donor for EPCs. In addition, the effects of vessel endothelial growth factor （VEGF） and passage on cell differentiation, expansion kinetics and apoptosis were examined, EPCs were determined and quantified by immunocytochemistry and flow cytometry, The results showed that both coculture of CD346＋ and CD34^- and total MNC led to a significant increase in the expansion of CD34^＋ cells as compared with CD34 enrichment （P〈0.05）. There was a tendency toward decreased apoptosis in cultures when early passage was performed immediately after cord like structures appeared. VEGF had no significant effect on apoptosis （P〉0.05）, These differentiated EPCs were positive for CD34^＋, von Willebrand factor （vWF）, KDR, CD31 staining and phagocytized acetylated low-density lipoprotein （LDL）. CD34^＋ cells accounted for （68.2±6,3） % of attaching （AT） cells at day 7 of culture. It was suggested the most efficient method to ex vivo expansion of EPCs was coculture of CD34^＋ and CD34^- or total MNC. Early passage makes cell apoptosis rate decrease. VEGF had no significant effect on ex vivo expansion of EPCs.
文摘In this paper,experimental findings concerning the kinetics of hematopoietic reconstitution are compared to corresponding clinical data.Although not clearly apparent,the transplantation practice seems to confirm the basic proposals of experimental hematology concerning hematopoietic reconstitution resulting from successive waves of repopulation stemming from different subpopulations of progenitor and stem cells.One of the "f irst rate" parameters in clinical transplantations in hematology;i.e.the CD34+ positive cell dose,has been discussed with respect to the functional heterogeneity and variability of cell populations endowed by expression of CD34.This parameter is useful only if the relative proportion of stem and progenitor cells in the CD34+ cell population is more or less maintained in a series of patients or donors.This proportion could vary with respect to the source,pathology,treatment,processing procedure,the graft ex vivo treatment and so on.Therefore,a universal dose of CD34+ cells cannot be def ined.In addition,to avoid further confusion,the CD34+ cells should not be named "stem cells" or "progenitor cells" since these denominations only concern functionally characterized cell entities.
