Research Progress on Immunomodulatory Activity and Clinical Application of Mesenchymal Stem Cells-Derived Extracellular Vesicles--Review / 中国实验血液学杂志

Mesenchymal stem cells (MSC) have been widely used in tissue regeneration and treatment graft versus host disease (GVHD) and immune diseases due to their self-renewal, multi-differentiation and immunoregulatory potential. However, more and more scholars begin to put weight on the MSC -derived extracellular vesicles (MSC-EV) for its regulation of inflammation and immunity. MSC-EV can activate the relevant signal pathways and regulate the function and biological behaviors of cells via acting on target cells and mediating communication between cells. MSC-EV has important potential clinical applications for its powerful immunomodulatory and hematopoietic regulatory functions. It is considered as a potential therapeutic tool to treat autoimmune diseases and GVHD. This paper reviewed the immunomodulatory activity of MSC-EV as well as the research progress of MSC-EV in hematopoietic stem cell transplantation, and discussed its potential clinical applications in the future.

A multicenter investigation and analysis on anemia in lymphoma patients in Shanghai / 中华血液学杂志

Objective: To investigate the occurrence and influencing factors of anemia in lymphoma patients and its effect on treatment. Methods: A total of 501 lymphoma patients, who were hospitalized in four general hospitals in Shanghai from January 2017 to June 2018, were followed up for six months. The clinical data about anemia were collected and statistically analyzed. Results: Among all the enrollment patients, there were 178 patients (35.5%) had anemia. Among 289 patients whom were initially treated for lymphoma, there were 99 patients (34.3%) with anemia. In the following-up time, there were 136 new cases (42.1%) of anemia. The total prevalence of anemia was 62.7%. The univariate analysis indicated that the anemia incidence for initially treated lymphoma patients was significantly related to their age, pathological type, bone marrow infiltration, IPI scores and Ann Arbor stage. The response to initially treatment in lymphoma patients with anemia was inferior to those without anemia. The multivariate analysis indicated that IPI scores 3-5 points (P<0.001, OR=4.230, 95%CI 2.339-7.650) and chemotherapy treatment (P<0.001, OR=11.049, 95%CI 5.149-23.711) were the independent influential factors to the emerging anemia incidence. PS score used to evaluate patient physical condition was obviously related to the anemia occurrence. Conclusion: Lymphoma patients have a high prevalence and incidence of anemia. The occurrence and severity of anemia are closely related to the efficacy and physical condition of lymphoma patients.

Down-regulation of transcription factor PU.1 via abnormal epigenetic modification in chronic myeloid leukemia / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the underlying mechanism and clinical significance of PU.1 down-expression in chronic myeloid leukemia (CML) patients.</p><p><b>METHODS</b>Different methylation status of PU.1 promoter region containing 20 CpG islands in normal individuals, CML chronic phase and blast crisis patients, complete cytogenetic remission patients after imatinib treatment, and blast crisis bone marrow K562 CML cells was detected by bisulfite sequencing. Semi-quantitative PCR was used to detect the PU.1 mRNA expression in normal controls, CML chronic phase and blast crisis patients, and blast crisis bone marrow K562 CML cells. Indirect immune fluorescence and Western blot were used to analyze the exprtession of PU.1 protein in normal individuals, CML chronic phase and blast crisis patients, and blast crisis bone marrow K562 CML cells.</p><p><b>RESULTS</b>Aberrant methylation in the promoter region of transcription factor PU.1 was found in both CML chronic phase and blast crisis phase bone marrow cells, as well as in CML blast K562 cells. Down-expression of PU.1 mRNA and protein levels was found in above cells. No methylation in the promoter region of PU.1 was observed in normal individuals, and the PU.1 mRNA and protein expressions were not reduced at all. Furthermore, high methylation status of bone marrow cells was even observed in the CML patients who acquired complete cytogenetic remission.</p><p><b>CONCLUSIONS</b>The results of our study indicate that the epigenetic modification of PU.1 in CML patients and K562 cell line might be responsible for the down-expression of PU.1. The data suggest that aberrant methylation of PU.1 plays a role in CML pathogenesis, therefore, it might serve as a useful biomarker and potential target in therapy for chronic myeloid leukemia.</p>

Effect of TGF-beta1 on biological characteristics of umbilical cord blood hematopoietic progenitor cells during ex-vivo expansion / 中国实验血液学杂志

To investigate the effects of TGF-beta1 on biological characteristics of hematopoietic progenitor cells (HPC) in umbilical cord blood (UCB) during ex-vivo expansion and feasibility of using it for expansion of UCB HPC, different concentrations of TGF-beta1 were added in the serum-free medium containing a combination of hematopoietic growth factors for expansion of UCB CD133(+) cells and enumeration of nucleated cells (NC), progenitor colonies, immunophenotyping, cell cycle and expression of adhesion molecules of the NC were monitored at every interval. The results showed that total number and expansion of NC from all groups of TGF-beta1 were remarkably less than those in control at each interval. However the content and total numbers as well as expansion of CD34(+), CD133(+), CD34(+)CD38(-) and CD34(+)CD133(+) cells from all groups of TGF-beta1 were more than those in control at each interval during expansion; the plating efficiency and expansion of CFU-GM, CFU-mix and HPP-CFC from NC of TGF-beta1 group were more than those in control at each interval. The contents of cells in G(0)/G(1) phase of NC of TGF-beta1 group at every interval were high. Meanwhile, TGF-beta1 could elevate the expression of some adhesion molecules on NC during expansion such as CD54, CD49d and CD11a, and the contents of CD34(+) cells coexpressing these adhesion molecules in NC of TGF-beta1 group were significantly more than those in control at each interval. In conclusion appropriate dose of TGF-beta1 could accelerate expansion of CD133(+) cells, delay and decrease over-differentiation of HPC, increase the content of HPC in expanded products, upregulate the expression of adhesion molecules on expanded HPC, thus it could promote engraftment of expanded progenitor cells and advantage the ex-vivo expansion of UCB HPC.

Studies on the dynamics of biological characteristics of CD133+ cells from human umbilical cord blood during short-term culture / 中国实验血液学杂志

This study was to investigate dynamics of biological properties of CD133(+) cells from human umbilical cord blood (UCB) during short-term culture containing the combination of hematopoietic growth factors and the feasibility of in vitro expansion of CD133(+) cells. The biology activities including analysis of cell cycle, immunophenotype, telomerase activity, expression of adhesion molecules and expansion potential of CD133(+) cells were monitored during ex-vivo expansion, and compared with those of CD34(+) cells. The results showed that the contents of CD133(+) and CD34(+) cells in fresh UCB were (1.05 +/- 0.73)% and (1.40 +/- 0.56)% respectively. About 79.62% of CD34(+) cells expressed CD133, and more than 97% of CD133(+) cells were CD133(+)CD34(+), markedly higher than that in CD34(+) fraction (P < 0.01). No significant differences were observed in content of cells expressing CD38, CD13, CD14, CD61 and glycophorin-A between the two fractions. Expansion of CD133(+), CD133(+)CD34(+) and CD34(+)CD38(-) cells at 10 days and those of CFU-mix, HPP-CFC and CD34(+)CD38(-) cells at 6 days from CD133(+) cells group were significantly higher than those from the CD34(+) cell group (P < 0.05). Analysis of immunophenotype showed that CD133(+)CD34(+) cells declined gradually while CD133(-)CD34(+) and CD133(-)CD34(-) cells increased during ex-vivo expansion; basal telomerase activities of fresh UCB CD133(+) and CD34(+) cells were low but significantly exceeded that of CD34(-) fraction (P < 0.05). At first week of expansion, telomerase activity was significantly upregulated, after two weeks, telomerase activity remarkably declined, and decreased to baseline or below the limits of detection in day 20. More than 90% of CD133(+) cells expressed CD49d and CD11a, and, more than 85% of the cells expressed CD54, about 50% of cells expressed CD62L. At the early stage of expansion, expression of CD49d was upregulated, expression of CD11a remaining no change, while as expression of CD54 and CD62L was downregulated. Expression of all adhesion molecules was decreased gradually with extend of culture. But expression of these adhesion molecules on CD34(+) subsets were not affected significantly during expansion. It is concluded that CD133(+) population may be a more primitive hematopoietic stem/progenitor cells (HSPC) than CD34(+) cells, CD133(+) cells have great expansion potential for ex-vivo expansion and is a suitable target cell for ex-vivo expansion of HSPC. Downregulation of adhesion molecules and telomerase activity may be one of the reasons for delayed engraftment of expanded products.