iPS细胞研究的新进展及应用

通过导入特定的转录因子可将分化的体细胞重编程为诱导性多能干细胞(Induced pluripotent stem cells,iPS cells),这项技术避免了干细胞研究领域的免疫排斥和伦理道德问题,是生命科学领域的一次巨大革命。与胚胎干细胞(Embryonic stem cells,ES cells)一样,iPS细胞能够自我更新并维持未分化状态,在体内可分化为3个胚层来源的所有细胞,进而参与形成机体所有组织和器官。在体外,iPS细胞可定向诱导分化出多种成熟细胞。因此,iPS细胞在理论研究和临床应用等方面都极具应用价值。文章对iPS细胞诱导的最新研究进展、iPS细胞诱导的不同方法,如何提高iPS细胞的制备效率和安全性,iPS细胞在基础研究以及临床研究等方面的应用进行了全面综述,并探讨了iPS细胞研究领域面临的问题以及该技术在转基因动物研究中的发展前景。     

诱导性多能干细胞向神经细胞分化的研究进展

诱导性多能干细胞(induced pluripotent stem cell,iPS cell)是通过转染外源特定的基因组合来诱导成体细胞重编程为类似于胚胎干细胞的一种多潜能干细胞,iPS细胞与胚胎干细胞不仅在形态上相似,而且在功能方面几乎相同.另外,iPS细胞的诞生克服了胚胎干细胞在临床应用时涉及的移植免疫排斥与伦理道德问题,因此具有重要的临床应用价值.目前iPS在治疗中枢神经系统性疾病方面的研究已取得很大进展,包括iPS细胞向神经细胞诱导分化方法的改进、分化机理的探索以及iPS细胞分化来源神经细胞在神经系统疾病模型中治疗作用的研究等.从iPS细胞的创建及特点、iPS细胞向神经细胞分化的诱导方法及研究新进展方面予以综述.     

诱导性多潜能干细胞(iPS cells)——现状及前景展望

主要从 iPS细胞发展历程、获得 iPS细胞的几个关键步骤 (如基因导入方式、诱导 iPS细胞所需因子组合与小分子化合物运用和体细胞种类选择等)、病人或疾病特异性 iPS细胞、iPS细胞体内外诱导分化与其衍生物的临床应用和制备无遗传修饰的(genetic modification-free) iPS细胞的可行性与前景等方面对 iPS细胞最新研究进展做评述．日本和美国研究小组先后用4种基因将小鼠(2006年8月)和人(2007年11～12月)的体细胞在体外重编程为诱导性多潜能干细胞(induced pluripotent stem cells,iPS cells),此后在短短两年多时间内,iPS 细胞的研究和关注度呈爆炸式增长．体细胞重编程、去分化和多潜能干细胞来源等一系列热点问题再次成为干细胞和发育生物学等研究的热点和焦点．与胚胎干细胞(embryonic stem cells,ES cells)一样,iPS细胞在体内可分化为3个胚层来源的所有细胞,进而参与形成机体所有组织和器官．迄今,在体外已由 iPS细胞定向诱导分化出功能性的多种成熟细胞．因此,iPS细胞研究不仅具有重要理论意义,而且在再生医学、组织工程和药物发现与评价等方面极具应用价值．     

诱导性多能干细胞的研究进展及其在再生医学上的应用

通过特定转录因子的过表达使体细胞重编程为诱导性多能干细胞(induced pluripotent stem cells,iPS细胞),这一成果引起了整个生命科学领域的广泛关注.由于iPS细胞不仅具有与人类胚胎干细胞(embryonicstem cell,ES细胞)相似的基本特征,而且与ES细胞相比,不存在免疫排斥和伦理道德问题,因此,具有重要的临床应用潜能.目前,iPS细胞主要用于细胞分化和移植,并可提供体外的疾病模型,以便于研究疾病形成的机制、筛选新药以及开发新的治疗方法.从iPS细胞的产生、诱导方法、生物学特征和在再生医学中的应用作以综述.     

诱导多能干细胞研究进展

人类诱导多能干细胞（induced pluripotent stem cells,iPS细胞）的建立被公认为目前最重要的科技进展之一。iPS细胞在动物疾病模型上的成功治疗,病患特异性iPS细胞的研究及iPS细胞的定向分化研究将有可能使人们避开治疗性克隆的伦理和技术障碍,给人类疾病的干细胞治疗带来光明的前景。本文从iPS细胞的诱导策略和方法,来源细胞及筛选、重编程机制的研究现状、应用前景以及研究中存在的问题等方面对其作一综述和讨论。     

体细胞重编程为诱导多能干细胞

诱导多功能性干细胞（induced pluripotent stem cells,iPS细胞）是通过导入特定的转录因子（如Oct3/4、Sox2、c-Myc和Klf4等）将体细胞诱导重编程为多能性干细胞,其功能与胚胎干细胞相似.iPS细胞的建立,在生命科学领域引起了新的轰动.目前,iPS细胞的研究领域在转录因子的优化、iPS细胞的筛选、载体的运用、体细胞种类的选择和iPS细胞的应用等方面取得突破进展,但仍然存在致癌性、效率低等一系列急需解决的问题.     

诱导多能干细胞的研究进展

体细胞诱导成为多能性干细胞(induced pluripotent stem cell,iPS cell)的研究成果被国际生命科学界誉为具有里程碑意义的创新之举.在短短3年多的时间里,这项研究已经在细胞重编程的机理研究、探索疾病的发生发展机制以及临床医学的应用等领域引发了很多突破性的进展,而且,这一非克隆干细胞技术的诞生,成功地避开了长期以来争论不休的伦理问题,极大地推动该领域和相关科学领域的发展.从iPS细胞的研究历程、iPS细胞的构建机理、iPS细胞研究的最新应用成果以及iPS细胞的发展前景和研究方向等方面进行了评.     

疾病特异诱导多能干细胞研究进展

通过病毒或非病毒转导体系,在小鼠和人的体细胞中人为表达几个与细胞多能性相关的转录因子,从而使细胞达到类似于胚胎干细胞（embryonic stem cells,ESCs）状态,是近年来新发展起来的体细胞重编程技术。这些被重编程的细胞称为诱导多能干细胞（induced pluripotent stem cells,iPS细胞）。这项技术为获得患者和疾病特异的多能干细胞提供了新的途径。患者和疾病特异的iPS细胞的获得,不仅在避免免疫排斥的宿主特异的细胞移植治疗上有广泛前景,并对了解疾病发生机理、药物筛选和毒性研究有着重要的意义。该文综述从iPS细胞技术的发明入手,着重讨论疾病iPS细胞的研究进展及其在应用于治疗时亟需解决的问题。     

诱导多能干细胞在心血管疾病研究和治疗中的应用

诱导多能干细胞（induced pluripotent stem cells,iPS细胞）不仅具有与胚胎干细胞（embryonic stem cell,ESC）相似的各项特性,相对于ESC,iPS细胞,尤其患者特异性iPS细胞还具有来源方便、不存在免疫排斥和伦理问题以及可以保留特定个体基因型等优点,为再生医学提供了可能的细胞来源。该文主要从心血管药物的筛选、疾病模型的建立、iPS细胞应用于心脏移植研究等方面入手,探讨了iPS细胞在心血管疾病研究和治疗中的现状和未来。     

直接重整细胞核程序的诱导性多能干细胞研究进展

诱导性多能干细胞（induced pluripotent stem cells, iPS）是分化细胞在外源性因子作用下,经直接细胞核程序重整而重新获得分化潜能的干细胞,具有很重要的应用前景。介绍了iPS诱导方法从转录因子、RNA结合蛋白、小分子化合物、到信号传导通路的发展过程,以及在提高生物安全性方面的改进。iPS的生成在细胞学上表现为渐进的、时间依赖的过程,同细胞的分化状态密切相关;然而,iPS同胚胎干细胞表遗传特征并非完全相同。iPS的进展结合基因治疗和细胞治疗的成果已应用到动物疾病模型的治疗。     

Human amniotic epithelial cell feeder layers maintain human iPS cell pluripotency via inhibited endogenous microRNA-145 and increased Sox2 expression

Currently, human induced pluripotent stem (iPS) cells were generated from patient or disease-specific sources and share the same key properties as embryonic stem cells. This makes them attractive for personalized medicine, drug screens or cellular therapy. Long-term cultivation and maintenance of normal iPS cells in an undifferentiated self-renewing state are a major challenge. Our previous studies have shown that human amniotic epithelial cells (HuAECs) could provide a good source of feeder cells for mouse and human embryonic stem cells, or spermatogonial stem cells, but the mechanism for this is unknown. Here, we examined the effect of endogenous microRNA-145 regulation on Sox2 expression in human iPS cells by HuAECs feeder cells regulation, and in turn on human iPS cells pluripotency. We found that human IPS cells transfected with a microRNA-145 mutant expressed Sox2 at high levels, allowing iPS to maintain a high level of AP activity in long-term culture and form teratomas in SCID mice. Expression of stem cell markers was increased in iPS transfected with the microRNA-145 mutant, compared with iPS was transfected with microRNA-145. Besides, the expression of Drosha proteins of the microRNA-processor complex, required for the generation of precursor pre-miRNA, was significantly increased in human iPS cells cultured on MEF but not on HuAECs. Taken together, these results suggest that endogenous Sox2 expression may be regulated by microRNA-145 in human iPS cells with HuAECs feeder cells, and Sox2 is a crucial component required for maintenance of them in an undifferentiated, proliferative state capable of self-renewal.     

(Re)defining stem cells

Stem-cell nomenclature is in a muddle! So-called stem cells may be self-renewing or emergent, oligopotent (uni- and multipotent) or pluri- and totipotent, cells with perpetual embryonic features or cells that have changed irreversibly. Ambiguity probably seeped into stem cells from common usage, flukes in biology's history beginning with Weismann's divide between germ and soma and Haeckel's biogenic law and ending with contemporary issues over the therapeutic efficacy of adult versus embryonic cells. Confusion centers on tissue dynamics, whether stem cells are properly members of emerging or steady-state populations. Clarity might yet be achieved by codifying differences between cells in emergent populations, including embryonic stem and embryonic germ (ES and EG) cells in tissue culture as opposed to self-renewing (SR) cells in steady-state populations.     

Rapid micropatterning of cell lines and human pluripotent stem cells on elastomeric membranes

Tissue function during development and in regenerative medicine completely relies on correct cell organization and patterning at micro and macro scales. We describe a rapid method for patterning mammalian cells including human embryonic stem cells (HESCs) and induced pluripotent stem cells (iPSCs) on elastomeric membranes such that micron‐scale control of cell position can be achieved over centimeter‐length scales. Our method employs surface engineering of hydrophobic polydimethylsiloxane (PDMS) membranes by plasma polymerization of allylamine. Deposition of plasma polymerized allylamine (ppAAm) using our methods may be spatially restricted using a micro‐stencil leaving faithful hydrophilic ppAAm patterns. We employed airbrushing to create aerosols which deposit extracellular matrix (ECM) proteins (such as fibronectin and Matrigel?) onto the same patterned ppAAm rich regions. Cell patterns were created with a variety of well characterized cell lines (e.g., NIH‐3T3, C2C12, HL1, BJ6, HESC line HUES7, and HiPSC line IPS2). Individual and multiple cell line patterning were also achieved. Patterning remains faithful for several days and cells are viable and proliferate. To demonstrate the utility of our technique we have patterned cells in a variety of configurations. The ability to rapidly pattern cells at high resolution over macro scales should aid future tissue engineering efforts for regenerative medicine applications and in creating in vitro stem cell niches. Biotechnol. Bioeng. 2012; 109: 2630–2641. © 2012 Wiley Periodicals, Inc.     

动物胚胎干细胞诱导分化的研究进展

胚胎干细胞 (ES细胞 )是从动物早期胚胎的内细胞团或原始生殖细胞分离出来的具有发育全能性的一种未分化的无限增殖细胞系 ,ES细胞能体外诱导分化为神经细胞、肌肉细胞、成纤维细胞等各种细胞。综述了动物的ES细胞的分化诱导机理及目前体外诱导分化的研究现状     

Cell differentiation lineage in the prostate

Prostatic epithelium consists mainly of luminal and basal cells, which are presumed to differentiate from common progenitor/stem cells. We hypothesize that progenitor/stem cells are highly concentrated in the embryonic urogenital sinus epithelium from which prostatic epithelial buds develop. We further hypothesize that these epithelial progenitor/stem cells are also present within the basal compartment of adult prostatic epithelium and that the spectrum of differentiation markers of embryonic and adult progenitor/stem cells will be similar. The present study demonstrates that the majority of cells in embryonic urogenital sinus epithelium and developing prostatic epithelium (rat, mouse, and human) co-expressed luminal cytokeratins 8 and 18 (CK8, CK18), the basal cell cytokeratins (CK14, CK5), p63, and the so-called transitional or intermediate cell markers, cytokeratin 19 (CK19) and glutathione-S-transferase-pi (GSTpi). The majority of luminal cells in adult rodent and human prostates only expressed luminal markers (CK8, CK18), while the basal epithelial cell compartment contained several distinct subpopulations. In the adult prostate, the predominant basal epithelial subpopulation expressed the classical basal cell markers (CK5, CK14, p63) as well as CK19 and GSTpi. However, a small fraction of adult prostatic basal epithelial cells co-expressed the full spectrum of basal and luminal epithelial cell markers (CK5, CK14, CK8, CK18, CK19, p63, GSTpi). This adult prostatic basal epithelial cell subpopulation, thus, exhibited a cell differentiation marker profile similar to that expressed in embryonic urogenital sinus epithelium. These rare adult prostatic basal epithelial cells are proposed to be the progenitor/stem cell population. Thus, we propose that at all stages (embryonic to adult) prostatic epithelial progenitor/stem cells maintain a differentiation marker profile similar to that of the original embryonic progenitor of the prostate, namely urogenital sinus epithelium. Adult progenitor/stem cells co-express both luminal cell, basal cell, and intermediate cell markers. These progenitor/stem cells differentiate into mature luminal cells by maintaining CK8 and CK18, and losing all other makers. Progenitor/stem cells also give rise to mature basal cells by maintaining CK5, CK14, p63, CK19, and GSTpi and losing K8 and K18. Thus, adult prostate basal and luminal cells are proposed to be derived from a common pleuripotent progenitor/stem cell in the basal compartment that maintains its embryonic profile of differentiation markers from embryonic to adult stages.     

人类及小鼠胚胎干细胞的不同多能性状态

胚胎干细胞(embryonic stem cells,ESCs)是来源于早期胚胎的全能性细胞,在合适条件下具有分化为任何一类成体细胞的潜力。在小鼠中,根据细胞来源的胚胎发育时间,ESCs可以被分为原始态多能性(na(?)ve pluripotency)和始发态多能性(primed pluripotency)两种状态。这两种状态的细胞在发育上相互联系,具有不同的形态、信号依赖、发育性质、基因表达及表观遗传学性质,并且在特定的条件下可以相互转化。人类胚胎干细胞(human embryonic stem cells,hESCs)的发育潜能曾一度被认为低于小鼠胚胎干细胞(mouse embryonic stem cells,mESCs),直到人类原始态胚胎干细胞的发现证明了hESCs可以表现出与mESCs相似的性质。这对于人类胚胎发育的研究及ESCs在临床治疗上的实际应用都具有重要的意义。     

Diploid,but not haploid,human embryonic stem cells can be derived from microsurgically repaired tripronuclear human zygotes

Human embryonic stem cells have shown tremendous potential in regenerative medicine, and the recent progress in haploid embryonic stem cells provides new insights for future applications of embryonic stem cells. Disruption of normal fertilized embryos remains controversial; thus, the development of a new source for human embryonic stem cells is important for their usefulness. Here, we investigated the feasibility of haploid and diploid embryo reconstruction and embryonic stem cell derivation using microsurgically repaired tripronuclear human zygotes. Diploid and haploid zygotes were successfully reconstructed, but a large proportion of them still had a tripolar spindle assembly. The reconstructed embryos developed to the blastocyst stage, although the loss of chromosomes was observed in these zygotes. Finally, triploid and diploid human embryonic stem cells were derived from tripronuclear and reconstructed zygotes (from which only one pronucleus was removed), but haploid human embryonic stem cells were not successfully derived from the reconstructed zygotes when two pronuclei were removed. Both triploid and diploid human embryonic stem cells showed the general characteristics of human embryonic stem cells. These results indicate that the lower embryo quality resulting from abnormal spindle assembly contributed to the failure of the haploid embryonic stem cell derivation. However, the successful derivation of diploid embryonic stem cells demonstrated that microsurgical tripronuclear zygotes are an alternative source of human embryonic stem cells. In the future, improving spindle assembly will facilitate the application of triploid zygotes to the field of haploid embryonic stem cells.     

人胚胎干细胞建系和鉴定

人胚胎干细胞是一种取自人囊胚内细胞团且具有形成所有三个胚层细胞能力的全能细胞。建立一个理想的人胚胎干细胞培养系统是研究和利用这种具有巨大潜力细胞的首要条件。本文讨论了目前建立的人胚胎干细胞培养系统,阐述了其有利的和不利的一面,并着重讨论其体外培养方法和鉴定策略。