阿尔茨海默病患者尿液细胞向诱导多能干细胞及神经细胞的诱导转化

目的:获得阿尔茨海默病(Alzheimer disease,AD)患者来源的诱导多能干细胞(induced pluripotent stem cells,i PSCs)。方法:选取3例临床诊断明确的AD病例,收集病人尿液,分离出尿路上皮细胞,对所得细胞进行原代培养。利用电转染的方法将带有Oct4、Sox2、Klf4和SV40LT的质粒导入原代细胞内,将其重编程为i PS细胞。随后利用双向抑制Smad通路的方式继续诱导其神经分化。结果:AD病人尿液来源的细胞(以下称为尿液细胞)均成功诱导成i PS细胞,其诱导效率与正常人来源的细胞无明显差异。且病人的i PS细胞可成功分化为神经细胞,分化效率亦与正常人来源细胞相近。结论:阿尔茨海默症患者来源的尿液细胞可重编程为i PS细胞,所得到的i PS细胞可成功分化成有功能的神经元以及神经胶质细胞。     

诱导多能性干细胞技术的进展

将人类体细胞诱导成为多能性干细胞(induced pluripotent stem cells,iPS cells)的研究成果为生物医学研究提供了广泛的前景,建立了一种全新的体细胞核重编程的方法,这种方法相对容易操作,而且比较稳定、安全,点燃了再生医学应用的新希望,本文从体细胞重编程的研究历程、iPS细胞技术的诱导因子、转录因子、载体及其应用价值方面进行了综述.     

成体干细胞诱导多能干细胞的研究进展

通过存在于卵母细胞中的一些未确定的因子,以成年细胞对动物进行克隆证实成年细胞能被重编程为胚胎干细胞(ESCs).近年来,某些转录因子被发现具有诱导体细胞且有多潜能性的特性,从而可以在不使用卵母细胞的情况下获得性能上与胚胎干细胞大体一致的诱导多能干细胞(iPS).iPS细胞为细胞多能性机制的研究、特定疾病模型的建立以及在...     

诱导多能干细胞的研究进展

人类组织工程的最终目的 是细胞在体外生长、分化为功能组织和器官以替代、修复、维持或者增强受损组织和器官功能.胚胎干细胞由于具有体外无限扩增的能力以及分化为机体各种类型细胞的潜能而成为组织工程中首选的细胞来源.主要就应用不同转录因子Oct3/4、Sox2、c-myc、Klf4、Nanog和LIN28经逆病毒导入未经遗传修改的成纤维细胞,从而使该类细胞去分化与重编程成具有分化为其它各种类型细胞的多能干细胞的研究进展作一综述.     

诱导多能干细胞在骨外科组织再生修复中：如何尽快实现临床应用？

背景：干细胞结合替代材料修复骨科组织缺损具有良好的应用前景,其中诱导多能干细胞有着比其他干细胞更优的来源及细胞特性,已成为干细胞领域的研究热点。 目的：综述诱导多能干细胞的研究历史、制备方法、细胞特性及目前在骨科领域的研究进展。 方法：利用计算机检索中国知网、PubMed等数据库1999至2014年间关于诱导多能干细胞及其应用于骨科领域研究的文献,选取具有代表性、创新性的研究成果进行内容论证。 结果与结论：研究表明诱导性多能干细胞在骨组织修复工程中表现出了相当有应用前景的优势,诱导性多能干细胞与各种支架材料都有着良好的相容性,在不同的支架中都保持着良好的成骨分化潜能。软骨再生方面的各种检测技术、小分子化合物等已逐步被发现,但如何有效地将诱导性多能干细胞向软骨方向诱导分化并实现临床应用仍需进一步研究。 中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程     

诱导多能干细胞:细胞疗法的未来生力军

该文就再生医学细胞疗法的潜力之星——诱导多能干细胞(ips)的相关技术、学术进展进行综合述评,包括诱导多能干细胞的诞生和特点、评价方法、靶向ips细胞株的建立及其价值等等,并展望了今后发展方向。     

诱导性多能干细胞体外定向诱导分化的研究进展

胚胎干细胞体外定向诱导分化的研究已成为发育生物学和细胞移植治疗学的研究热点,但伦理及免疫排斥问题一直阻碍胚胎干细胞（ES）的研究和临床应用。近两年,科学家成功地从多种成体细胞获得了诱导性多能干细胞（iPS细胞）,iPS细胞具有和胚胎干细胞相似的特性,由于其可来自自体成体细胞,因而可避开伦理及免疫排斥问题,是胚胎干细胞良好的替代材料,具有广阔的应用前景。iPS只有诱导分化为成熟的功能细胞才能用于疾病的治疗。主要介绍iPS细胞向成熟细胞分化的研究现状及目前存在的一些问题。     

多能干细胞制备方法的研究进展及问题

多能干细胞为研究疾病的分子机制、药物筛选及再生医学应用提供理想的细胞来源,然而,当前多能干细胞的来源或制备方法面临众多瓶颈和挑战,本文回顾了多能干细胞制备方法的最新研究进展,为多能干细胞的后续研究提供思路。     

诱导多能干细胞建系及体外造血祖细胞定向分化体系的建立

背景：目前,大量文献报道了诱导多能性干细胞系的建立,但大规模体外诱导分化造血祖细胞的研究还缺乏深入的探讨。 目的：建立诱导多能性干细胞体外定向诱导形成造血祖细胞的方法。 方法：采用慢病毒感染的方法将含有Oct4、Sox2、Nanog和Lin28全能性基因的慢病毒颗粒转导人皮肤成纤维细胞,获得了诱导多能性干细胞;在诱导分化体系中添加了Y-27632,克服干细胞扩增中的凋亡现象;运用OP9细胞产生的条件培养液建立诱导多能性干细胞体外定向分化形成造血祖细胞的分化体系。 结果与结论：①前3代细胞克隆传代时,诱导多能性干细胞发生凋亡的现象很多,很难大规模扩增培养。培养基中添加阻断ROCK活化的抑制剂,能够明显抑制胚胎干细胞的凋亡。②诱导多能性干细胞在OP9细胞条件培养液作用下,经过体外诱导分化,形成CD34+造血祖细胞。中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程全文链接：     

乙醇诱导小鼠导致骨髓多能干细胞成脂分化

实验证明乙醇可引起股骨头内脂肪积聚,导致骨坏死,其作用机制尚不清楚。本研究旨在观察乙醇对骨髓多能干细胞（D1细胞）的直接作用,进一步阐明乙醇性骨坏死的发病机制。     

In vivo liver regeneration potential of human induced pluripotent stem cells from diverse origins

Human induced pluripotent stem cells (iPSCs) are a potential source of hepatocytes for liver transplantation to treat end-stage liver disease. In vitro differentiation of human iPSCs into hepatic cells has been achieved using a multistage differentiation protocol, but whether these cells are functional and capable of engrafting and regenerating diseased liver tissue is not clear. We show that human iPSC-derived hepatic cells at various differentiation stages can engraft the liver in a mouse transplantation model. Using the same differentiation and transplantation protocols, we also assessed the ability of human iPSCs derived from each of the three developmental germ layer tissues (that is, ectoderm, mesoderm, and endoderm) to regenerate mouse liver. These iPSC lines, with similar but distinct global DNA methylation patterns, differentiated into multistage hepatic cells with an efficiency similar to that of human embryonic stem cells. Human hepatic cells at various differentiation stages derived from iPSC lines of different origins successfully repopulated the liver tissue of mice with liver cirrhosis. They also secreted human-specific liver proteins into mouse blood at concentrations comparable to that of proteins secreted by human primary hepatocytes. Our results demonstrate the engraftment and liver regenerative capabilities of human iPSC-derived multistage hepatic cells in vivo and suggest that human iPSCs of distinct origins and regardless of their parental epigenetic memory can efficiently differentiate along the hepatic lineage.     

Residual undifferentiated cells during differentiation of induced pluripotent stem cells in vitro and in vivo

Induced pluripotent stem (iPS) cells are a potential cell source for regenerative medicine. However, the tumorigenicity of iPS cells is a big concern for clinical application. In addition to the genetic manipulation of the reprogramming process and the greater risk of tumor formation, it is unclear whether iPS cells with normal development potential are still tumorigenic. Here, we investigated 3 mouse iPS cell lines, including one line that is able to generate full-term mice via tetraploid blastocyst complementation. We found that a small number of undifferentiated iPS cells could be steadily isolated and expanded after long-term differentiation of cells in vitro or in vivo. The residual undifferentiated iPS cells could be expanded and redifferentiated, and undifferentiated pluripotent stem cells could again be isolated after further rounds of differentiation, suggesting that residual undifferentiated iPS cells could not be eliminated by extended cell differentiation. The residual undifferentiated cells could form teratomas in vivo, indicating that they are a potential tumorigenic risk during transplantation. These findings prompt us to reconsider the strategies for solving the tumorigenic problem of iPS cells, not only focusing on improving the reprogramming process.     

Development of rat antigen-presenting cells from pluripotent ecto-mesenchymal stem cells in vitro and in vivo

Dendritic cells (DC) are specialized cells that capture and present antigen to T cells. Recent advances have been made in understanding their origin, heterogeneity, and the signals that induce their migration and maturation resident microglia are antigen-presenting cells (APC) involved in stimulation or reactivation of CNS-targeted T cells. Generation of DC from microglia, as demonstrated ex vivo, may support GM-CSF-driven differentiation of brain DC from local, likely, microglial progenitors. Here, we report the establishment of long-term cultures of rat ecto-mesenchymal stem cells (EMSCs) using specific supplemented media for induction. These EMSCs share some morphological characteristics and the allostimulatory capacity of classical DCs, and when transplanted into the brain using a rat glioma model survive within the cortex, and are morphologically and phenotypically similar to microglia over 7 days. Our findings related to the development and differentiation of microglial progenitors support the view that microglia are derived prenatally from mesodermal progenitors that are distinct from monocytes.     

Patient-specific cardiovascular progenitor cells derived from integration-free induced pluripotent stem cells for vascular tissue regeneration

Tissue-engineered blood vessels (TEBVs) are promising in regenerating a live vascular replacement. However, the vascular cell source is limited, and it is crucial to develop a scaffold that accommodates new type of vascular progenitor cells and facilitates in vivo lineage specification of the cells into functional vascular smooth muscle cells (VSMCs) to regenerate vascular tissue. In the present study, integration-free human induced pluripotent stem cells (hiPSCs) were established from patient peripheral blood mononuclear cells through episomal vector nucleofection of reprogramming factors. The established hiPSCs were then induced into mesoderm-originated cardiovascular progenitor cells (CVPCs) with a highly efficient directed lineage specification method. The derived CVPCs were demonstrated to be able to differentiate into functional VSMCs. Subcutaneous implantation of CVPCs seeded on macroporous nanofibrous poly(l-lactide) scaffolds led to in vivo VSMC lineage specification and matrix deposition inside the scaffolds. In summary, we established integration-free patient-specific hiPSCs from peripheral blood mononuclear cells, derived CVPCs through directed lineage specification, and developed an advanced scaffold for these progenitor cells to further differentiate in vivo into VSMCs and regenerate vascular tissue in a subcutaneous implantation model. This study has established an efficient patient-specific approach towards in vivo regeneration of vascular tissue.     

诱导多能性干细胞研究进展

人类诱导多能性干细胞（iPS细胞）的出现被誉为生命科学领域里新的里程碑,它建立了一种全新的、相对易操作而较稳定的体细胞核重编程方法,在生物学基础研究和临床应用方面具有潜在的价值;然而,iPS细胞的高癌变率和极低的重编程效率大大限制了它的应用。目前iPS细胞技术正在被不断完善,就iPS细胞的研究历程及在诱导iPS细胞上的最新研究进展进行综述。     

Concise review: induced pluripotent stem cells and lineage reprogramming: prospects for bone regeneration

Bone tissue for transplantation therapies is in high demand in clinics. Osteodegenerative diseases, in particular, osteoporosis and osteoarthritis, represent serious public health issues affecting a respectable proportion of the elderly population. Furthermore, congenital indispositions from the spectrum of craniofacial malformations such as cleft palates and systemic disorders including osteogenesis imperfecta are further increasing the need for bone tissue. Additionally, the reconstruction of fractured bone elements after accidents and the consumption of bone parts during surgical tumor excisions represent frequent clinical situations with deficient availability of healthy bone tissue for therapeutic transplantations. Epigenetic reprogramming represents a powerful technology for the generation of healthy patient-specific cells to replace or repair diseased or damaged tissue. The recent generation of induced pluripotent stem cells (iPSCs) is probably the most promising among these approaches dominating the literature of current stem cell research. It allows the generation of pluripotent stem cells from adult human skin cells from which potentially all cell types of the human body could be obtained. Another technique to produce clinically interesting cell types is direct lineage reprogramming (LR) with the additional advantage that it can be applied directly in vivo to reconstitute a damaged organ. Here, we want to present the two technologies of iPSCs and LR, to outline the current states of research, and to discuss possible strategies for their implementation in bone regeneration.     

人诱导性多能干细胞定向分化为神经干细胞的实验研究

目的 观察人诱导性多能干细胞（iPS细胞）定向分化为神经干细胞（NSCs）的潜能。方法 用维甲酸（RA）诱导人iPS细胞向NSCs分化。倒置显微镜下观察iPS细胞的形态变化,RT-PCR检测NANOG, OCT4, SOX2的表达;免疫组织化学方法检测NESTIN、SOX2、β-TUBULIN Ш和GFAP的表达。结果RA诱导后第4天,贴壁的拟胚体出现了早期神经祖细胞特有的神经管样结构并不断增多,细胞表达神经巢蛋白NESTIN,而对照组未观察到神经管样结构。神经管样结构内的细胞能分化为β-TUBULIN Ш阳性的神经元,但GFAP阳性的星形胶质细胞少见。结论 人iPS细胞具有定向分化为NSCs的潜能,并能模拟神经发育过程。     

人多能干细胞的冷冻与保存

背景：人多能干细胞的出现与发展是近年来生物医学研究领域的重大突破。但其在基础/临床研究中的广泛应用还有诸多限制,建立安全有效标准化的冷冻保存方案是人多能干细胞广泛应用面临的重大挑战。 目的：回顾人多能干细胞冷冻领域的研究进展,探索造成冷冻损伤的原因和机制及改进方式,致力于促进新的更有效的冷冻方案形成。 方法：以“人多能干细胞、人胚胎干细胞、人诱导多能干细胞、玻璃化、程序化冷冻、慢冻法、冷冻保存”为中文检索词,以“human pluripotent stem cells,human embryonic stem cell,human introduced pluripotent stem cell,vitrification,programmed cryopreservation,slow-freezing,cryopreservation”为英文检索词,应用计算机检索中国知网全文数据库、万方全文数据库、维普(VIP)期刊全文数据库、PubMed数据库有关人多能干细胞冷冻保存技术的文献,排除与研究目的无关及重复文献,保留58篇文献进一步总结分析。 结果与结论：了解人多能干细胞冷冻过程中造成冷冻损伤的原因和机制,是寻找高效的冻存方案的关键。需要更清晰的了解冷冻过程中损伤的原理,改进和创新低温生物技术来避免各种冷冻损伤的发生并致力于探讨可重复的,高效的,符合GMP要求的,能大规模冻人多能干细胞的方案。中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程全文链接：