Role of bone marrow-derived mesenchymal stem cells in reduction of graft-versus-host disease by effecting CD4+CD25+ regulatory T cells in rats / 中国实验血液学杂志

The study was purposed to investigate the effects and mechanism of bone marrow-derived mesenchymal stem cells (MSCs) on graft-versus-host desease (GVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT). The model of GVHD in rat had been established by allo-HSCT with donor derived T cells. The occurence of GVHD in recipients was observed in condition with or without donor derived MSC co-transplantation. Effects of MSCs on GVHD were analyzed by model rat survival rate and pathology. Proportions of CD4+CD25+ regulatory T cells were determined by using label spleen lymphocytes and thymocytes with double fluorescent-labeled antibodies and flow cytometry. The results showed that MSCs inhibited the lethal GVHD after HSC co-transplantation and increased the survival rate. The ratio of CD4/CD8 deceased in GVHD group in different levels, as compared with that in the experimental group. The proportion of CD4+CD25+ regulatory T cells of spleen lymphocytes was 31.55 +/- 7.58% and 20.90 +/- 1.90% in experimental and GVHD groups, respectively. Similarly, the proportion of CD4+CD25+ regulatory T cells of thymocytes was 93.20 +/- 2.69% and 57.17 +/- 6.79% in experimental and the GVHD groups, respectively. Meanwhile the proportion of CD4+CD25+ regulatory T cells was higher in experimental group than that in GVHD group. It is concluded that MSCs may prevent the lethal GVHD after allo-HSC co-transplantation and raise the survival rate of model rats by acting on the CD4+CD25+ regulatory T cells in vivo.

Tumor necrosis factor-alpha induces release of endothelial microparticles from human endothelial cells / 中华心血管病杂志

<p><b>OBJECTIVE</b>The present study was designed to investigate whether Tumor necrosis factor (TNF)-alpha stimulates release of endothelial microparticles (EMPs) by human endothelial cells, and whether EMPs may serve as a promising marker for endothelial injury and dysfunction.</p><p><b>METHODS</b>Human umbilical venous endothelial cells (HUVEC) were incubated with or without TNF-alpha for 24 hours at 37 degrees C. EMPs generated on the surface of HUVEC were observed with a scanning electron microscopy. The CD31 and CD51 positive EMPs in culture supernatants were measured by flow cytometer.</p><p><b>RESULTS</b>Fewer vesicles were observed on cell surface of control group, in TNF-alpha-stimulated one, however, cells manifested a blebby surface (eruption phenomenon) and more vesicles on surface were observed. The levels of EMPs were significantly increased in TNF-alpha stimulated cells compared with controls [CD31 + EMP, (164 +/- 63)/1000 cells vs. (42 +/- 10)/1000 cells, P < 0.05; CD51 + EMP, (260 +/- 108)/1000 cells vs. (19 +/- 4)/1000 cells, P < 0.05].</p><p><b>CONCLUSION</b>TNF-alpha can stimulate HUVEC to release EMPs which may serve as a surrogate marker for endothelial injury and dysfunction.</p>