ABSTRACT
Abstract Angiogenesis plays a key role in tumor growth, invasion and metastasis of cancer diseases and therefore, the inhibition of angiogenesis can provide an important therapeutic approach in cancer diseases. This study was designed to compare the anti-angiogenic activities of the ethanolic extract of Artemisia sieberi Besser, Asteraceae, and its active substance, artemisinin in both in vitro and in vivo models. To compare cytotoxicity level of ethanolic extract of A. sieberi with artemisinin, different concentrations (1–100 µg/ml) were tested using MTT assay on human umbilical vein endothelial cells. The anti-angiogenic properties of serial concentrations of ethanolic extract of A. sieberi and artemisinin were examined on human umbilical vein endothelial cells using a three-dimensional angiogenesis assay (in vitro model) and in the chick chorioallantoic membrane assay as in vivo model. The effects of ethanolic extract of A. sieberi and artemisinin were also tested on the expression of VEGFR-1, VEGFR-2 and CD34 genes using real-time PCR. Ethanolic extract of A. sieberi and artemisinin significantly (p < 0.001) inhibited the angiogenesis in the human umbilical vein endothelial cells culture whilst the ethanolic extract of A. sieberi showed higher effect in a concentration-dependent fashion (p < 0.001). The chick chorioallantoic membrane angiogenesis was also completely inhibited by ethanolic extract of A. sieberi at concentration of 33 ng/100 µl/egg. The gene expression analysis showed that the ethanolic extract of A. sieberi and artemisinin reduced the transcription of VEGFR-1, VEGFR-2 and CD34 genes in a concentration-dependent manner. This study demonstrated that the ethanolic extract of A. sieberi is strongly able to inhibit the angiogenesis in human umbilical vein endothelial cells and chick chorioallantoic membrane models compared to the artemisinin.
ABSTRACT
The adhesion of leukocytes to vascular endothelium is crucial for the generation of inflammatory responses. The selectinsand β2-integrin (Mac-1) play a major role in the process. Recently, it was reported that RO-heparin can inhibit selectin-mediated leukocyte adhesion. The effect of RO-heparin on the Mac-1-mediated neutrophils adhesion were further tested. The results showed that RO-heparin could effectively inhibit neutrophils binding to ICAM-1, adhering to COS-7 cells expressing human ICAM-1, and adheringto human umbilical vein endothelial cells (HUVECs) under static and flow conditions. The findings suggest that the effect of RO-heparin on leukocyte adhesion is mainly due to its inhibition on the interaction between selectins or Mac-1 and their ligands and that RO-heparin might be useful in preventing inflammation diseases.
ABSTRACT
The adhesion of leukocytes to vascular endothelium is crucial for the generation of inflammatory responses. The selectins and ?2-integrin (Mac-1) play a major role in the process. Recently, it was reported that RO-heparin can inhibit selectin-mediated leukocyte adhesion. The effect of RO-heparin on the Mac-1-mediated neutrophils adhesion were further tested. The results showed that RO-heparin could effectively inhibit neutrophils binding to ICAM-1, adhering to COS-7 cells expressing human ICAM-1, and adhering to human umbilical vein endothelial cells (HUVECs) under static and flow conditions. The findings suggest that the effect of RO-heparin on leukocyte adhesion is mainly due to its inhibition on the interaction between selectins or Mac-1 and their ligands and that RO-heparin might be useful in preventing inflammation diseases.
ABSTRACT
BACKGROUND: We examined an ex vivo expansion system for cord blood (CB) hematopoietic progenitor cells, which is based upon a co-culture of CD34+cells with human umbilical endothelial cells (HUVECs) in the presence of stromal cell-derived factor-1 (SDF-1) and hematopoietic growth factors. METHODS: Cord blood CD34+cells were either incubated a liquid suspension culture or co-cultured on HUVEC monolayers with hematopoietic growth factors in the presence or absence of SDF-1. After 7~14 days of culture, cells were harvested and analyzed for fold-increase in nucleated cells, CD34+ cells, and colony-forming cells (CFCs) and apoptosis. RESULTS: Seven-day suspension culture of CD34+ cells in the presence of a cytokine combination consisting of throbmopoietin, flk-2 ligand, and kit-ligand (TFK) led to a 43-fold increase of nucleated cells, a 19-fold increase of CD34+ cells, and 14-fold increase of CFCs, respectively. The addition of SDF-1 to TFK slightly further increased this expansion. A co-culture of CD34+ cells with HUVECs significantly enhanced the expansion of both CD34+ cells and CFCs compared with a liquid suspension culture. This was further increased by the addition of SDF-1. A co-culture of CD34+ cells on HUVECs transfected with null-adenoviral vector led to a better fold increase of haemtopoietic progenitor cells compared with a culture with non-transfected HUVECs. Adding SDF-1 to the co-culture diminished the annexn V-positive cells both in the supernatant and adherent cell layers. CONCLUSION: A co-culture of cord blood cells with HUVECs in the presence of hematopoietic growth factors and SDF-1 could be a new model for the efficient expansion of hematopoietic progenitors.
Subject(s)
Humans , Apoptosis , Coculture Techniques , Endothelial Cells , Fetal Blood , Hematopoietic Stem Cells , Human Umbilical Vein Endothelial Cells , Intercellular Signaling Peptides and Proteins , Stem CellsABSTRACT
The administration of erythropoietin for renal failure patients is frequently associated with a mild-to-marked rise in arterial blood pressure. The erythropoietin-induced hypertension has been variably attributed to the rise in erythrocyte concentration and/or a direct or indirect pressor action of erythropoietin on vascular smooth muscle. Especially erythropoietin-induced hypertension may be mediated by increased production of the potent vasoactive peptide endothelin. This study was designed to determine the effect of erythropoietin to the production of endothelin in human glomerular endothelial cells and human umbilical vein endothelial cells. ELISA method was used to measure the endothelin- 1, after 4 X 10(4) endothelial cells were grown to confluency on 24-well plates, in which erythropoietin 25u/ml was incubated for 24 hours. The results showed that the endothelin production in human glomerular endothelial cells was insignificant (116.0+/-14.0%, P>0.05, mean+/-S.E., n=5, each n means the mean of duplicate experiments), but the endothelin production in human umbilical endothelial cells was increased after 25u/ml erythropoietin treatment(126.5+/-15.2%, P<0.05, mean+/-S.E., n=4). In glomerular endothelial cells, TGF-beta(0.5ng/ml) increased the production of endothelin(218.8+/-57.2%, P<0.01, mean+/-S.E., n=5), also it looks like that TNF-alpha and thrombin might increase the production of endothelin according to the concentration. In conclusion, the responsiveness of endothelial cells to erythropoietin may be different according to the cell type, and glomerular endothelial cells could increase the production of endothelin, if appropriate stimuli were given.