间充质干细胞促进脐带血干细胞体外扩增的研究进展

非亲缘脐带血移植是治疗造血系统疾病的重要移植方式之一,但脐带血移植面临的最大挑战是造血干细胞(HSCs)数量不足,特别是成人患者受到脐带血干细胞数量的限制,导致造血及免疫恢复延迟,非复发死亡率升高。体外扩增脐带血HSCs(UCB-HSCs)是解决该问题的途径之一。研究发现可以通过模拟骨髓造血龛(niche)这一生态位使HSCs在体外进行自我更新增殖,而间充质干细胞(MSCs)正是造血龛的重要的组成细胞之一。本文将探讨MSCs在UCB-HSCs体外扩增中的应用。重点以MSCs促造血的特点、机制,促进脐带血干细胞增殖的各种策略以及其临床应用和前景做一综述。     

脐带血造血干细胞治疗糖尿病的研究进展

脐带血造血干细胞具有极强的自我更新和多向分化潜能,为治疗糖尿病开辟了新的途径,造血干细胞在生成胰岛素分泌细胞前需要经过诱导分化、细胞选择和细胞成熟三个阶段。目前,脐带血造血干细胞在治疗糖尿病中已取得一定进展,将造血干细胞定向分化为胰岛β细胞成为了治疗的关键。本文通过对脐带血的特征、造血干细胞的制备和移植、糖尿病的治疗以及脐带血造血干细胞移植的利与弊等方面进行的归纳总结,分析脐带血造血干细胞在治疗糖尿病方面的进展和应用前景。     

脐带血来源干细胞神经分化的研究进展

中枢神经系统损伤后的自身修复能力有限,因而研究者致力于寻找一种合适的细胞进行移植以代替受损的神经细胞修复神经损伤。近年来的研究表明,脐带血干细胞能够在体外诱导条件下向神经样细胞分化,并在动物体内实验中促进神经损伤的恢复,有可能作为一种有效的细胞资源,应用于人类中枢神经系统疾病的细胞替代治疗以及神经保护与支持。     

脐带血来源间充质干细胞体外分离培养条件的优化

脐带血间充质干细胞（umbilical cord blood mesenchymal stem cells,UCB-MSCs）不仅可以作为滋养层细胞支持造血干细胞在体外的大规模扩增,在造血移植过程中还能够降低并发症的发生率以及加速造血重建功能的恢复．但是,目前UCB-MSCs的原代分离培养成功率一般只有30％左右,为进一步提高该成功率,利用正交实验方法对UCB-MSCs体外培养的主要影响因素：细胞的接种密度、细胞因子的组合及用量、是否添加血清和滋养层细胞,进行逐层筛选,并对培养出的间充质干细胞进行了流式细胞分析和向成骨、软骨及脂肪方向的诱导分化检测,以期获得UCB-MSCs培养的最佳方法．实验结果表明,细胞的接种密度是UCB-MSCs培养最显著的影响因素（P〈0．1）,接种密度越大,MSCs越容易生长,能够培养出MSCs的几率就越大,其次为细胞因子,添加细胞因子能有效地刺激MSCs的生长．在高接种密度的基础上,添加细胞因子IL-3（15μg／L）和GM-CSF（5μg/L）,可大大提高UCB-MSCs体外原代培养的成功率,从30％左右提高到90％以上．流式细胞检测结果显示,所分离培养的细胞表达间充质干细胞的抗原（CD13^＋、CD29^＋、CD44^＋、CD105^＋、CD166^＋）,不表达造血细胞的抗原（CD34^-、CD45^-、HLA-DR^-）,并能够向成骨、软骨及脂肪方向分化,这与源于骨髓的间充质干细胞相一致．所建立的培养方法能够为UCB-MSCs的临床应用提供大量优质的种子细胞．     

脐带血干细胞的基础与应用研究

作为造血干/祖细胞(hematopoieticstemcells/hematopoieticprogenitorcells,HSCs/HPCs)的另一来源,脐带血已经应用于临床治疗多种恶性和非恶性疾病。脐带血中HSCs/HPCs的质与量是决定其临床应用效果的最重要因素。同时,脐带血中还存在多种非造血的干细胞和前体细胞,如间充质干细胞(mesenchymalstemcells,MSCs)、内皮前体细胞(endothelialprogenitorcells,EPCs)和非限制性体干细胞(unrestrictedsomaticstemcells,USSCs)等,这些细胞可能会在未来的细胞治疗和再生医学中发挥重要作用。本综述还讨论了脐带血的临床应用及HSCs/HPCs的体外扩增、增加HSCs归巢和再植能力等提高其临床应用能力的相关研究。     

造血干/祖细胞的体外扩增和临床应用

介绍造血干 / 祖细胞的体外培养和扩增取得的显著进展 :包括各种生物反应器的应用 ,三维培养系统的建立。扩增后的造血细胞在动物模型和临床上的应用已取得了初步成效。     

UM171和SR1对不同来源造血干/祖细胞体外扩增的作用研究

目的探讨小分子化合物UM171和SR1对脐带血、供者动员外周血和淋巴瘤患者自体动员外周血3种来源的造血干/祖细胞(HSPCs)体外扩增的作用。方法将3种来源的CD34+细胞分别予以UM171、SR1干预后进行体外扩增培养,记为对照组、UM171组、SR1组和UM171+SR1组。通过细胞计数检测各组总有核细胞的数量,流式细胞术检测HSPCs的比例、各谱系分化细胞的比例和HSPCs上归巢相关因子CXCR4的表达水平。多组数据若满足方差齐性,采用单因素方差分析,组间两两比较采用LSD-t检验;若方差不齐,多组间比较以及两两比较均采用Kruskal-Wallis检验。结果与对照组比较,UM171和SR1均能促进3种来源HSPCs的比例升高,同时UM171能够增加3种来源HSPCs的扩增倍数。与对照组比较,UM171处理后脐带血来源的CD33^+(髓系)细胞的比例升高,CD41^+(巨核)细胞的比例降低;SR1处理后3种来源的CD3-CD56^+(自然杀伤)细胞的比例均升高。体外扩增48 h后各组HSPCs上CXCR4的表达较培养前增加。结论UM171能够有效扩增3种来源HSPCs的数量,促进脐带血来源HSPCs分化为髓系细胞并抑制其分化为巨核细胞。SR1能够促进3种来源HSPCs分化为自然杀伤细胞。体外扩增培养可以提高3种来源HSPCs上CXCR4的表达水平。     

造血干细胞的研究进展

干细胞研究是一门新兴的学科。经过50多年的努力,造血干细胞的研究已经成为当今生物医学领域中发展最快的领域。介绍了造血干细胞的来源、分离纯化和检测方法以及“可塑性”等方面的研究情况,并详细说明了一些主要的造血干细胞表面标志以及造血干细胞在干细胞移植、细胞治疗和基因治疗等方面的临床应用和前景。     

造血干细胞体外培养模式的研究进展

造血干细胞(hematopoietic stem cells,HSC)的体外培养可为造血干细胞移植提供大量的造血干细胞,具有重要的临床意义。HSC体外培养方式从二维培养发展到三维培养,从静态培养发展到动态培养,其培养技术及效果日趋成熟,其中以生物反应器为主的动态三维培养具有明显的优势。本文就HSC体外培养的研究进展作一综述。     

造血干细胞体外培养模式的研究进展

造血干细胞（hematopoietic stem cells,HSC）的体外培养可为造血干细胞移植提供大量的造血干细胞,具有重要的临床意义。HSC体外培养方式从二维培养发展到三维培养,从静态培养发展到动态培养,其培养技术及效果日趋成熟,其中以生物反应器为主的动态三维培养具有明显的优势。本文就HSC体外培养的研究进展作一综述。     

Initial CD34+ cell-enrichment of cord blood determines hematopoietic stem/progenitor cell yield upon ex vivo expansion

Since umbilical cord blood (UCB), contains a limited hematopoietic stem/progenitor cells (HSC) number, successful expansion protocols are needed to overcome the hurdles associated with inadequate numbers of HSC collected for transplantation. UCB cultures were performed using a human stromal‐based serum‐free culture system to evaluate the effect of different initial CD34⁺ cell enrichments (Low: 24 ± 1.8%, Medium: 46 ± 2.6%, and High: 91 ± 1.5%) on the culture dynamics and outcome of HSC expansion. By combining PKH tracking dye with CD34⁺ and CD34⁺CD90⁺ expression, we have identified early activation of CD34 expression on CD34^? cells in Low and Medium conditions, prior to cell division (35 ± 4.7% and 55 ± 4.1% CD34⁺ cells at day 1, respectively), affecting proliferation/cell cycle status and ultimately determining CD34⁺/CD34⁺CD90⁺ cell yield (High: 14 ± 1.0/3.5 ± 1.4‐fold; Medium:22 ± 2.0/3.4 ± 1,0‐fold; Low:31 ± 3.0/4.4 ± 1.5‐fold) after a 7‐day expansion. Considering the potential benefits of using expanded UCB HSC in transplantation, here we quantified in single UCB units, the impact of using one/two immunomagnetic sorting cycles (corresponding to Medium and High initial progenitor content), and the average CD34⁺ cell recovery for each strategy, on overall CD34⁺ cell expansion. The higher cell recovery upon one sorting cycle lead to higher CD34⁺ cell numbers after 7 days of expansion (30 ± 2.0 vs. 13 ± 1.0 × 10⁶ cells). In particular, a high (>90%) initial progenitor content was not mandatory to successfully expand HSC, since cell populations with moderate levels of enrichment readily increased CD34 expression ex‐vivo, generating higher stem/progenitor cell yields. Overall, our findings stress the importance of establishing a balance between the cell proliferative potential and cell recovery upon purification, towards the efficient and cost‐effective expansion of HSC for cellular therapy. J. Cell. Biochem. 112: 1822–1831, 2011. © 2011 Wiley‐Liss, Inc.     

Preclinical transplantation and safety of HS/PCs expanded from human umbilical cord blood

AIM: To expand hematopoietic/progenitor stem cells (HS/PCs) from umbilical cord blood (UCB) and prepare the HS/PC product, and analyze preclinical transplantation and safety of HS/PC product. METHODS: Human bone marrow-derived mesenchymal stem cells (MSCs) were used as feeder cells to expand HS/PCs from UCB in a serum-free culture system. The proliferation potential of HS/PCs was analyzed. The expanded HS/PCs were suspended in the L-15 medium to prepare the HS/PC product. The contamination of bacteria, fungi and mycoplasmas, the infection of exogenous virus, the concentration of bacterial endotoxin, and the SCF residual in HS/PC product were determined. Finally, cells from the HS/PC product with or without bone marrow-derived mesenchymal stem cells (BM-MSCs) were transplanted into the irradiated NOD/SCID mice to determine the in vivo engraftment potential. RESULTS: After co-culture for 10 d, the total nuclear cells (TNCs) increased 125-fold, and CD34 + cells increased 43-fold. The granulocyte-macrophage colonyforming cells (GM-CFCs) and erythroid colony-forming cells (E-CFCs) increased 3.3and 4.7-fold respectively. The expanded cells were collected and prepared as the expanded product of HS/PCs by re-suspending cells in L-15 medium. For preclinical safety, the HS/PC product was analysed for contamination by bacteria, fungi and mycoplasmas, the bacterial endotoxin concentration and the SCF content. The results showed that the HS/PC product contained no bacteria, fungi or mycoplasmas. The bacterial endotoxin concentration was less than the detection limit of 6 EU/mL, and residual SCF was 75 pg/mL. Based on clinical safety, the HS/PC product was qualified for clinical transplantation. Finally, the HS/PC product was transplanted the irradiated mice where it resulted in rapid engraftment of hematopoietic cells. CONCLUSION: HSPC product prepared from UCB in the serum-free culture system with hMSCs as feeder cells should be clinically safe and effective for clinical transplantation.     

Human mesenchymal stem cells from the umbilical cord matrix: Successful isolation and ex vivo expansion using serum-/xeno-free culture media

Mesenchymal stem cells (MSC) could potentially be applied in therapeutic settings due to their multilineage differentiation ability, immunomodulatory properties, as well as their trophic activity. The umbilical cord matrix (UCM) represents a promising source of MSC for biomedical applications. The number of cells isloated per umbilical cord (UC) unit is limited and ex vivo expansion is imperative in order to reach clinically meaningful cell numbers. The limitations of poorly defined reagents (e.g. fetal bovine serum, which is commonly used as a supplement for human MSC expansion) make the use of serum-/xeno-free conditions mandatory. We demonstrated the feasibility of isolating UCM-MSC by plastic adherence using serum-/xeno-free culture medium following enzymatic digestion of UCs, with a 100% success rate. 2.6 ± 0.21 × 10⁵ cells were isolated per UC unit, of which 1.9 ± 0.21 × 10⁵ were MSC-like cells expressing CD73, CD90, and CD105. When compared to adult sources (bone marrow-derived MSC and adipose-derived stem/stromal cells), UCM-MSC displayed a similar immunophenotype and similar multilineage differentiation ability, while demonstrating a higher expansion potential (average fold increase of 7.4 for serum-containing culture medium and 11.0 for xeno-free culture medium (P3-P6)). The isolation and expansion of UCM-MSC under defined serum-/xeno-free conditions contributes to safer and more effective MSC cellular products, boosting the usefulness of MSC in cellular therapy and tissue engineering.     

Mesenchymal stem cells from cryopreserved human umbilical cord blood

Umbilical cord blood (UCB) is well known to be a rich source of hematopoietic stem cells with practical and ethical advantages, but the presence of mesenchymal stem cells (MSCs) in UCB has been disputed and it remains to be validated. In this study, we examined the ability of cryopreserved UCB harvests to produce cells with characteristics of MSCs. We were able to obtain homogeneous plastic adherent cells from the mononuclear cell fractions of cryopreserved UCB using our culture conditions. These adherent cell populations exhibited fibroblast-like morphology and typical mesenchymal-like immunophenotypes (CD73+, CD105+, and CD166+, etc.). These cells presented the self-renewal capacity and the mesenchymal cell-lineage potential to form bone, fat, and cartilage. Moreover, they expressed mRNAs of multi-lineage genes including SDF-1, NeuroD, and VEGF-R1, suggesting that the obtained cells had the multi-differentiation capacity as bone marrow-derived MSCs. These results indicate that cryopreserved human UCB fractions can be used as an alternative source of MSCs for experimental and therapeutic applications.     

脐血造血细胞体外保存及扩增的研究

研究了脐血造血细胞在4℃冰箱保存过程中单核细胞活力、造血性能的变化以及细胞因子种类、组合、不同培养基添加成分对造血细胞扩增的影响。研究表明脐血在4℃冰箱保存应不超过3d;细胞因子组合SCF IL-6 FL TPO扩增CFU—C的效果最佳;培养基体系中添加脐血混合血浆对扩增CFU—C作用明显,脐血混合血浆的最佳浓度为25％。     

Experimental study on ex vivo expanded hematopoietic stem/progenitor in the two step culture from human umbilical cord blood transplanted into NOD/SCID mice

The effects of hematopoietic stem/progenitor cells (HSPCs) expanded in the two step coculture with human bone marrow mesenchymal stem cells (hMSCs) on the hematopoietic reconstruction of irradiated NOD/SCID mice were studied. Mononuclear cells (MNCs) were isolated from human umbilical cord blood (UCB) and cultured in the non-coculture scheme of rhSCF + rhG-CSF + rhMDGF combination and the coculture scheme of rhSCF + rhG-CSF + rhMDGF + hMSCs. Sublethally-irradiated NOD/SCID mice were transplanted with ex vivo expanded HSPCs with the dose of 8.5 × 10⁶ cells per mouse. After transplantation, the dynamics of WBC in the transplanted mice was measured periodically, and the Alu sequence fragment special for human in the transplanted mice was inspected by PCR. Results showed that the coculture scheme increased proliferation of UCB-derived HSPCs. After transplantation with expanded HSPCs, the population of WBC in the transplanted mice increased in 12 d and reached the first peak in 25 d, then showed the second increasing of WBC in 45∼55 d. Expanded cells from the coculture scheme appeared to be favorable for the second increasing of WBC in the transplanted mice. After 85 d, the Alu sequence fragment was detected in the probability of 87.5% (7/8) for the non-coculture scheme and 88.9% (8/9) for the coculture scheme. __________ Translated from Journal of Zhejiang University (Science Edition), 2005, 32 (4) [译自: 浙江大学学报 (理学版), 2005, 32 (4)]     

Experimental study on ex vivo expanded hematopoietic stem/progenitor in the two step culture from human umbilical cord blood transplanted into NOD/SCID mice

The effects of hematopoietic stem/progenitor cells(HSPCs)expanded in the two step coculture with human bone marrow mesenchymal stem cells(hMSCs)on the hematopoietic reconstruction of irradiated NOD/SCID mice were studied.Mononuclear cells(MNCs)were isolated from human umbilical cord blood(UCB)and cultured in the non-coculture scheme of rhSCF+rhG-CSF +rhMDGF combination and the coculture scheme of rhSCF+rhG-CSF+rhMDGF+hMSCS.Sublethally-irradiated NOD/SCID mice were transplanted with ex vivo expanded HSPCS with the dose of 8.5×106 cells per mouse.After transplantation.the dynamics of WBC in the transplanted mice was measured periodically,and the Alu sequence fragment special for human in the transplanted mice was inspected by PCR.Results showed that the coculture scheme increased proliferation of UCB-derived HSPCs.After transplantation with expanded HSPCS,the population of WBC in the transplanted mice increased in 12 d and reached the first peak in 25 d,then showed the second increasing of WBC in 45～55 d.Expanded cells from the coculture scheme appeared to be favorable for the second increasing of WBC in the transplanted mice.After 85 d,the Alu sequence fragment was detected in the probability of 87.5%(7/8)for the non-coculture scheme and 88.9%(8/9)for the coculture scheme.     

用悬浮搅拌培养体系体外大量扩增人脐血造血干/祖细胞

目的 :建立一种简便、有效的脐血造血干 /祖细胞体外大量扩增培养体系。方法 :淋巴细胞分离液分离的脐血单个核细胞在SCF ,IL - 3,IL - 6三种细胞因子的作用下 ,于悬浮搅拌培养体系中培养 ,分析其总细胞数、CFU -GM、CD34+ 细胞的扩增倍数。结果 :脐血单个核细胞在悬浮搅拌培养体系中培养 12天后 ,其总细胞数、CFU -GM、CD34+ 细胞的扩增倍数分别为 6 .31± 1.5 2 ,2 0 .6 3± 1.5 4和 7.11± 1.12。结论 :悬浮搅拌培养体系是脐血造血干 /祖细胞体外大量扩增的有效培养体系。