ABSTRACT
OBJECTIVE@#To investigate the effect of microvascular endothelial cells (MEC) on the proliferation of hematopoictic stem cells (HSC) under different culture conditions in vitro.@*METHODS@#The MEC from lung tissue of C57BL/6 mice and the HSC from bone marrow of GFP mice were used for non-contact co-culture, 2 D contact co-culture, at same time the single MEC and single HSC culture were seted up and were used as control group. The cell counting and CCK-8 method were used to detect and compare the proliferation levels of suspension cells in different groups on day 1, 3, 5 and 7.@*RESULTS@#MEC presented adherent growth. In process of cell culture in vitro, the number of suspension cells in MEC and HSC co-culture group and single HSC culture group increased, the suspension cells in 2D contact and non-contact co-culture groups more early gated into logarithmic growth phase as compared with suspension cells in control group, the proliferation level of suspention cells in 2D contact culture group was higher than that in non-contact co-culture group and single HSC culture group (P<0.05), the proliferation level of suspension cells in non-contact co-culture group was higher than that in single HSC culture group (P<0.05).@*CONCLUSION@#The culture of HSC in vitro can proliferate HSC, MEC can promote the proliferation of HSC, MEC also can promote the HSC proliferation by non-contact co-culture in vitro, which relates with the effect of cytokines secreted from MEC; the effect of MEC and HSC contact co-culture on the proliferation of HSC is stronger than that of non-contact co-culture, which relates with the regulation of cell-cell contact.
Subject(s)
Animals , Mice , Bone Marrow , Bone Marrow Cells , Cell Proliferation , Endothelial Cells , Hematopoietic Stem Cells , Mice, Inbred C57BLABSTRACT
<p><b>OBJECTIVE</b>To study the effect and mechanism of shh and mesenchymal stem cell（MSC）synergism on the proliferation of hematopoietic stem cells in noninvasive co-culture system in vitro.</p><p><b>METHODS</b>The mesenchymal stem cells were cultured in vitro，CD34 cells were sorted by mini MACS magnetic bead separator，flow cytometry was used to identify the purity of 2 cells. CD34 cells and MSCs were seeded to upper and low of transwell respecibely for non-contact coculture，and add exogenous shh protein for intervenece. The number of MSCs and HSCs，the total amount of RNA，the expression of ki67 and Tie-2 mRNA of HSC，the expression of VEGF and Ang-1 mRNA of MSC were detected for investigating the condition of cell proliferation and the expression of angiogenic factors.</p><p><b>RESULTS</b>The total number of cells，the total amount of RNA and the relative expression of ki67, Tie-2, VEGF and Ang-1 in non-contact co-culture group increased and showed the following trends on the 7th day：the above-mentioned indexes in group MSC + HSC, group shh + HSC were higher than those in group HSC, while those in MSC + shh + HSC Group was higher than those in MSC + HSC and shh + HSC group.</p><p><b>CONCLUSION</b>Angiogenic factors help MSC to proliferate HSC and amplify the CD34 hematopoietic stem/progenitor cells by shh and MSC synergism in vitro coculture system which may be related with angiogenic factors.</p>
ABSTRACT
BACKGROUND: Although a large number of related studies have been carried out, there is still a lack of practical methods to amplify hematopoietic stem cells(HSCs)in vitro.Mesenchymal stem cells(MSCs)secrete a variety of cytokines that promote the HSCs proliferation and inhibit their differentiation. These cytokines play an important role in maintaining the hematopoietic microenvironment and regulating HSCs function. OBJECTIVE:To investigate the effect of bone marrow MSCs on the proliferation of HSCs in vitro under different coculture modes. METHODS:Mesenchymal stem cells from the bone marrow of C57BL/6 mice were cultured in vitro using the whole bone marrow adherent culture. CD117+cells (HSCs) were sorted from passage 3 cells by using miniMACS magnetic beads sorting. Then, CD117+cells were co-cultured with MSCs under different coculture models, including single culture of HSCs (control group), Transwell coculture (upper chamber, HSCs; lower chamber, MSCs) and two-dimensional contact coculture (coculturing HSCs and MSCs in 24-well plates). The morphology of HSCs was observed under phase contrast microscope and fluorescence microscope, and the number of active cells of HSCs was counted at 1, 3, 5, and 7 days after coculture. RESULTS AND CONCLUSION: During the coculture of 1-7 days, the number of HSCs in the two groups was increased with culture time (P <0.05). After 3 days of coculture, HSCs in each group was grown into the logarithmic growth phase, and morphological changes in some HSCs were detected at 5 days of coculture. At 7 days of coculture, the viabilities of HSCs in different culture models were ranked as follows: single culture model < Transwell coculture model < two-dimensional contact coculture model (P < 0.05). These findings suggest that MSCs can effectively promote the proliferation of HSCs in vitro,and the promotion effect is increased under contact coculture conditions.
ABSTRACT
<p><b>OBJECTIVE</b>To re-evaluate and compare the research design and the use of statistical methods in Chinese Journal of Cardiology.</p><p><b>METHOD</b>Summary the research design and statistical methods in all of the original papers in Chinese Journal of Cardiology all over the year of 2011, and compared the result with the evaluation of 2008.</p><p><b>RESULTS</b>(1) There is no difference in the distribution of the design of researches of between the two volumes. Compared with the early volume, the use of survival regression and non-parameter test are increased, while decreased in the proportion of articles with no statistical analysis. (2) The proportions of articles in the later volume are significant lower than the former, such as 6(4%) with flaws in designs, 5(3%) with flaws in the expressions, 9(5%) with the incomplete of analysis. (3) The rate of correction of variance analysis has been increased, so as the multi-group comparisons and the test of normality. The error rate of usage has been decreased form 17% to 25% without significance in statistics due to the ignorance of the test of homogeneity of variance.</p><p><b>CONCLUSION</b>Many improvements showed in Chinese Journal of Cardiology such as the regulation of the design and statistics. The homogeneity of variance should be paid more attention in the further application.</p>