Production of mature red blood cell by using peripheral blood mononuclear cells / 中国实验血液学杂志

Most protocols for in vitro producing red blood cells (RBC) use the CD34(+) cells or embryonic stem cells from cord blood, bone marrow or peripheral blood as the start materials. This study was purposed to produce the mature RBC in vitro by using peripheral blood mononuclear cells as start material. The peripheral blood mononuclear cells (PBMNC) were isolated from buffy coat after blood leukapheresis, the mature red blood cells (RBC) were prepared by a 4-step culture protocol. The results showed that after culture by inducing with the different sets of cytokines and supporting by mouse MS-5 cell line, the expansion of PBMNC reached about 1000 folds at the end of the culture. About 90% of cultured RBC were enucleated mature cells which had the comparable morphological characteristics with normal RBC. Colony-forming assays showed that this culture system could stimulate the proliferation of progenitors in PBMNC and differentiate into erythroid cells. The structure and function analysis indicated that the mean cell volume of in vitro cultured RBC was 118 ± 4 fl, which was slight larger than that of normal RBC (80-100 fl); the mean cell hemoglobin was 36 ± 1.2 pg, which was slight higher than that of normal RBC (27-31 pg); the maximal deformation index was 0.46, which approachs level of normal RBC; the glucose-6-phosphate dehydrogenase and pyrurvate kinase levels was consistant with young RBC. It is concluded that PBMNC are feasble, convenient and low-cost source for producing cultured RBC and this culture system is suitable to generate the RBC from PBMNC.

Influence of cytokine combinations on proliferation and differentiation of umbilical cord blood CD34(+) cells into megakaryocytes/platelets in vitro / 中国实验血液学杂志

In order to investigate the influence of cytokine combinations on proliferation and differentiation of human umbilical cord blood CD34(+) cells into megakaryocytes/platelets in vitro, the CD34(+) cells from human umbilical cord blood were amplified in serum-free medium StemSpan(SFEM) supplemented with several cytokine combinations by three-phase culture system. The effects of the cytokine combinations were compared. The results showed that at day 14 of the first culture phase, the CD34(+) cells cultured with cytokine combinations SCF + TPO + FL + IL-3 were amplified (11 000 ± 1 000) times, which were significantly higher than that of cells cultured with SCF + TPO + FL, but were not significantly different from that of cells cultured with SCF + TPO + IL-3 or SCF + TPO + FL + IL-3+ hydroxyl-corticosteroids. At day 7 of the second culture phase, the CD34(+) cells cultured with cytokine combination SCF + TPO + FL + IL-11 were amplified by (204666.7 ± 11718.9) times, which were significantly higher than that of cells cultured with SCF + TPO + FL + IL-3, but were not significantly different from that of cells cultured with SCF + TPO + FL + IL-11 + BMP4 + VEGF. At day 3 and day 6, the CD34(+) platelet-like cells accounted for about (39.8 ± 1.9)%, (39.7 ± 2.6)% and (25.5 ± 1.4)%, (23.1 ± 3.5)% cultured with SCF + TPO + FL + IL-11 and SCF + TPO + FL + IL-11 + BMP4 + VEGF, and significantly higher than that of the cells cultured with SCF + TPO + FL + IL-3. It is concluded that the cytokine combination of SCF + TPO + FL + IL-3 is most suitable cytokines combination for the amplification of CD34(+) hematopoietic progenitor cells. The cytokine combination of SCF + TPO + FL + IL-11 is preferred for the proliferation and differentiation of megakaryocytes, this study lays an experimental basis for investigating the proliferation and differentiation of CD34(+) into megakaryocytes/platelets in vitro.

Investigation on induced expansion of erythroid cells from cord blood CD34(+) cells in vitro / 中国实验血液学杂志

This study was aimed to investigate a beneficial approach for resolving the deficiency of blood source, preventing the infection resulting from blood transfusion and overcoming the knotty match of patients with rare blood group by using massive expansion of erythroid cells from cord blood CD34(+) cells in vitro. The CD34(+) cells from human cord blood were cultured in serum-free medium supplemented with stem cell factor (SCF), interleukin-3 (IL-3) and erythropoietin (EPO) for 1 week, then expansion and differentiation of CD34(+) cells into erythroid cells were supported by co-culture with human mesenchymal stem cells (MSCs) derived from bone marrow for 2 weeks. The results indicated that after culture for 23 days, the expansion multiple of total cell number reached 2.52 x 10(5), and over 95% of these cells were erythroid cells as compared with less than 1% of myelomonocytic (CD14(+) or CD15(+)) cells and megakaryocytic (CD41(+)) cells. However, the culture system without MSC support was significantly disadvantaged both in expansion ability and ratio of erythroid cells when compared with MSC supporting system. It is concluded that the erythroid cells can be produced from CD34(+) cells in large scale by culturing in the system comprised of cytokine sets and MSC feeders, in which MSCs can support the proliferation and differentiation of erythroid cells.

INFLUENCE OF HEAT STRESS ON AMPK ACTIVITY AND LIPID METABOLITES OF / 营养学报

Objective: To study the influence of high cell incubating temperature on AMP-activated protein kinase(AMPK) activity and lipid metabolites of piglets hepatocytes in vitro.Method: Primary hepatocytes of piglets about age 55d were separated and cultured under 37 ℃(control) or 42 ℃(heat stress).The anabolic and catabolic products of [14C]-oleic acid were detected for hepatocytes and culture media at 60min,120min and 180min.There were 9 replicates per time point.Result: Heat stress activated AMPK activity and enhanced fatty acid oxidation.The production of [14C]-CO2 and [14C]-acid soluble metabolites(ASM) was higher in heat stress group than in the control.At the same time,heat stress depressed the incorporation of [14C]-oleate into phospholipids,monoglycerides,triglycerides,cholesterol and cholesteryl ester.Conclusion: Heat stress activated AMPK activity and enhanced the formation of anabolic products and depressed catabolic products in piglets hepatocytes in vitro.