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1.
Stem Cell Res Ther ; 10(1): 376, 2019 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-31806004

RESUMO

BACKGROUND: The umbilical cord blood (UCB) has been widely accepted as an alternative source of hematopoietic stem/progenitor cells (HSPCs) for transplantation, and its use in adults is still restricted because of low absolute numbers. To overcome this obstacle, expansion of UCB-HSPCs under feeder cell-based coculture is a promising possibility. In this study, we explored UCB-CD34+ cells ex vivo expansion using Wharton's jelly mesenchymal stem cells (WJ-MSCs) or umbilical vein endothelial cells (UVECs) as feeder layer-based serum-free coculture system with a cocktail of cytokines. METHODS: UCB-CD34+ cells were cultured in five different coculture conditions composed of umbilical cord stromal cells (WJ-MSCs or UVECs) with or without a cocktail of cytokines (SCF, FLT3L, and TPO). The cultured cells were harvested at day 10 and analyzed for phenotypes and functionalities, including total nuclear cells (TNCs), CD34+ cells, CD34+CD38- cells, colony-forming unit (CFU) for committed progenitors, and long-term culture initiating cells (LTC-ICs) for HSPCs. RESULTS: Our work showed the numbers of TNC cells, CD34+ cells, and CD34+CD38- cells were expanded under five coculture conditions, and the feeder layer-based cocultures further promoted the expansion. The numbers of colonies of CFU-GM, CFU-E/BFU-E, and CFU-GEMM in the cocultures with cytokines were significantly higher than their counterparts at day 0 (p < 0.05), while no significant difference (p > 0.05) in those without the addition of cytokines. The numbers of LTC-ICs were increased both under the WJ-MSCs and UVECs with cytokine cocultures, but only in the UVECs group showed a significant difference (p < 0.05), and were decreased under conditions without cytokine (p < 0.05). CONCLUSION: Our data demonstrate that both WJ-MSCs and UVECs as feeder layer could efficiently support the expansion of UCB-CD34+ cells in synergy with SCF, FLT3L, and TPO under serum-free culture condition. The UVECs combined with the 3GF cytokine cocktail could maintain the growth of LTC-ICs derived from UCB-CD34+ cells and even expand to some extent.

2.
Stem Cell Res Ther ; 9(1): 158, 2018 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-29895317

RESUMO

BACKGROUND: The physiological approach suggests that an environment associating mesenchymal stromal cells with low O2 concentration would be most favorable for the maintenance of hematopoietic stem/progenitor cells (HSPCs). To test this hypothesis, we performed a coculture of cord blood CD34+ cells with Wharton's jelly mesenchymal stem cells (WJ-MSCs) under different O2 concentration to simulate the growth of HSPCs in vivo, and assessed the impacts on stemness maintenance and proliferation of cord blood HSPCs in vitro. METHODS: CD34+ cells derived from cord blood were isolated and cocultured under 1%, 3%, or 20% O2 concentrations with irradiated WJ-MSCs without adding exogenous cytokines for 7 days. The cultured cells were harvested and analyzed for phenotype and functionality, including total nuclear cells (TNC), CD34+Lin- cells, colony forming unit (CFU) for committed progenitors, and long-term culture initiating cells (LTC-ICs) for HSPCs. The cytokine levels in the medium were detected with Luminex liquid chips, and the mRNA expression of hypoxia inducible factor (HIF) genes and stem cell signal pathway (Notch, Hedgehog, and Wnt/ß-catenin) downstream genes in cord blood HSPCs were confirmed by quantitative real-time polymerase chain reaction (qRT-PCR). RESULTS: Our results showed that the number of TNC cells, CD34+Lin- cells, and CFU were higher or similar with 20% O2 (normoxia) in coculture and compared with 1% O2 (hypoxia). Interestingly, a 1% O2 concentration ensured better percentages of CD34+Lin- cells and LTC-IC cells. The hypoxia tension (1% O2) significantly increased vascular endothelial growth factor (VEGF) secretion and decreased interleukin (IL)-6, IL-7, stem cell factor (SCF), and thrombopoietin (TPO) secretion of WJ-MSCs, and selectively activated the Notch, Wnt/ß-catenin, and Hedgehog signaling pathway of cord blood HSPCs by HIF-related factors, which may play an important role in stemness preservation and for sustaining HSPC quiescence. CONCLUSIONS: Our data demonstrate that cord blood HSPCs maintain stemness better under hypoxia than normoxia with WJ-MSC coculture, partially due to the increased secretion of VEGF, decreased secretion of IL-6 by WJ-MSCs, and selective activation of stem cell signal pathways in HSPCs. This suggests that the oxygenation may not only be a physiological regulatory factor but also a cell engineering tool in HSPC research, and this may have important translational and clinical implications.


Assuntos
Antígenos CD34/metabolismo , Hipóxia Celular/fisiologia , Técnicas de Cocultura/métodos , Sangue Fetal/metabolismo , Células-Tronco Mesenquimais/metabolismo , Geleia de Wharton/metabolismo , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Humanos
3.
Clin Lab ; 63(10): 1639-1645, 2017 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-29035454

RESUMO

BACKGROUND: Increasing numbers of studies have been carried out on the association of MDM2 T309G polymorphism with susceptibility to leukemia and have generated conflicting results. This meta-analysis updated and revaluated the possible associations between MDM2 T309G polymorphism and leukemia in the Chinese population. METHODS: The PubMed, Springer Link, Ovid, Chinese Wanfang Data Knowledge Service Platform, Chinese National Knowledge Infrastructure, and Chinese Biology Medicine were searched up to February 2017. Fixed-effect and random-effect meta-analytical techniques were conducted for the outcome measure and subgroup analyses. RESULTS: Overall, the meta-analysis demonstrated significant associations between the MDM2 T309G polymorphism and increased risk for leukemia in the Chinese population. Subgroup analyses indicated similar results in South China. As for subgroup analysis by clinical types, data suggested increased risk for chronic myeloid leukemia (CML). CONCLUSIONS: Our study suggested that MDM2 T309G polymorphism might be a low-penetrant risk factor for leukemia among Chinese.


Assuntos
Leucemia/genética , Proteínas Proto-Oncogênicas c-mdm2/genética , Grupo com Ancestrais do Continente Asiático/genética , Predisposição Genética para Doença , Humanos , Polimorfismo Genético
4.
Indian J Hematol Blood Transfus ; 30(Suppl 1): 227-31, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25332585

RESUMO

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired hematopoietic stem cell clinical disease, which has been reported associated with T cell monoclonal expansion and plasma cell dyscrasias. There we reported a case with a 20-year clinical history of PNH. Lately diagnosis of Waldenström macroglobulinemia with the offered evidences of bone marrow examination, flow cytometry and immunofixation electrophoresis. T cell monoclonal expansion was established by polymerase chain reaction. Meanwhile the decreased expression of CD55 and CD59 on neutrophils and erythrocyte were obvious observed. Here we describe the diagnostic evaluation of this patient and provide a brief review of such clonal disorder.

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