The Establishment of Embryonic Cardiac Stem Cell Lines

1 IntroductionIt is critical to seek ideal seed cells for the development of cardiovascular tissue engineering (CvTE). Currently autologous vascular wall cells (AVWCs) and marrow stromal cells (MSCs) represent established cell sources for CvTE. However, the invasive harvesting of vessel segments or bone marrow, a wound brought to body, are required duing cells isolation. Furthermore, these autologous cells was greatly limited in clinical applications, because the fussy experiment in vitro culture can be per...     

The Practical Consequences of a National Human Embryonic Stem Cell Registry

The executive order and issuance of federal guidelines for human embryonic stem cell research are positive developments and will produce long-term benefits by creating a new registry for hESC lines. But there may be short-term costs caused by regulatory uncertainty, procedural delay, and knock-on effects as national policies are adopted at state and local jurisdictions. Policymakers must ensure that national mechanisms of oversight for a new hESC registry are adequately funded, properly organized, transparent, and free of bureaucratic detail.     

Epigenetic Control of Embryonic Stem Cell Differentiation

Pluripotent embryonic stem cells can give rise to almost all somatic cell types but this characteristic requires precise control of their gene expression patterns. The necessity of keeping the entire genome “poised” to enter into any of a number of developmental possibilities requires a unique and highly plastic chromatin organisation based around specific patterns of histone modifications although this state of affairs is normally short lived during embryonic development. By deriving embryonic stem cells from the early embryo, we can preserve the highly specialised genome organisation and this has permitted several detailed investigations into the molecular basis of pluripotency.     

The Race Is On: Human Embryonic Stem Cell Research Goes Global

More nations are joining the human embryonic stem cell (hESC) ??race?? by aggressively publishing in the peer-reviewed journals. Here we present data on the international use and distribution of hESC using a dataset taken from the primary research literature. We extracted these papers from a comprehensive dataset of articles using hESC and human induced pluripotent stem cells (hiPSC). We find that the rate of publication by US-based authors is slowing in comparison to international labs, and then declines over the final year of the period 2008?C2010. Non-US authors published more frequently and at a significantly higher rate, significantly increasing the number of their papers. In addition, international labs use a more diverse set of hESC lines and Obama-era additions are used more in non-US locations. Even considering the flood of new lines in the US and abroad, we see that researchers continue to rely on a few lines derived before the turn of the century. These data suggest ??embargo?? effects from restrictive policies on the US stem cell field. Over time, non-US labs have freely used lines on the US registries, while federally funded US scientists have been limited to using those lines approved by the NIH.     

胚胎干细胞定向分化的研究进展

胚胎干细胞已成为组织工程、发育生物学、药物开发及基因研究的热点。本文仅就胚胎干细胞定向分化的机制、研究进展和应用前景作一综述 ,旨在进一步推动胚胎干细胞的研究工作。     

MicroRNA对干细胞生物学行为的调控

目的：随着人类基因组计划的完成,对于RNA在生物体内功能的研究日益受到重视。自1993年的第一个microR—NA（miRNA）,lin-4,发现以来,人们逐渐意识到生物体内有这样一些非编码的RNA,它们对基因的表达调控起着非常重要的作用。研究表明,在生物界存在着一个庞大的miRNA家族,参与调控生物体生长发育等许多复杂的生命过程,并且与干细胞的自我更新和多向分化存在着紧密关联。miRNA通过与靶位点结合快速有效地降解靶基因miRNA或抑制蛋白质的翻译,下调CDK,cyclin,p21,p27等关键的细胞周期调控因子的表达,调控各种类型干细胞的更新与分化;miRNA还可以决定干细胞的命运,促进ips。本文主要论述了干细胞中miRNA作用通路及其对干细胞生物学行为的调控。     

Porcine Embryonic Stem Cells: A Possible Source for Cell Replacement Therapy

The development of porcine embryonic stem cell lines (pESC) has received renewed interest given the advances being made in the production of immunocompatible transgenic pigs. However, difficulties are evident in the production of pESCs in-vitro. This may largely be attributable to differences in porcine pre-implantation development compared to the mouse and human. Expression of oct4, nanog and sox2 differs in the zona-enclosed porcine blastocyst compared to its mouse and human counterparts, which may suggest that other factors may be responsible for maintaining porcine pluripotency in the early blastocyst. In addition, the epiblast forms considerably later, at days 7 to 8 when the porcine blastocyst begins to hatch and is maintained for 4 days before completely differentiating. This review covers an outline of the known molecular profile during porcine pre-implantation development and provides a history in the development of putative pESCs to date. Greater knowledge on the molecular mechanisms that underlie porcine pluripotency and pre-implantation development may aid in improving the development of pESCs.     

Optimized Protocol for Derivation of Human Embryonic Stem Cell Lines

For the past 12 years, the biology and applications of human embryonic stem cells (hESCs) have received great attention from the scientific community. Derivatives of the first hESC line obtained by J. Thomson's group (Science 282(5391):1145-1147, 1998) have been used in clinical trials in patients with spinal cord injury, and other hESC lines have now been used to generate cells for use in treating blindness (Lancet 379(9817):713-720, 2012). In addition to the classical protocol based on mouse or human feeder layers using open culture methods (In Vitro Cellular & Developmental Biology - Animal 46(3-4):386-394, 2010; Stem Cells 23(9):1221-1227, 2005; Nature Biotechnology 24(2):185-187, 2006; Human Reproduction 21(2):503-511, 2006; Human Reproduction 20(8):2201-2206, 2005; Fertility and Sterility 83(5):1517-1529, 2005), novel hESC lines have been derived xeno-free (without using animal derived reagents) (PLoS One 5 (4):1024-1026, 2010), feeder-free (without supporting cell monolayers) (Lancet 365(9471):1601-1603, 2005), in microdrops under oil (In Vitro Cellular & Developmental Biology - Animal 46(3-4):236-41, 2010) and in suspension with ROCK inhibitor (Nature Biotechnology 28(4):361-4, 2010). Regardless of the culture system, successful hESC derivation usually requires optimization of embryo culture, the careful and timely isolation of its inner cell mass (ICM), and precise culture conditions up to the establishment of pluripotent cell growth during hESC line derivation. Herein we address the crucial steps of the hESC line derivation protocol, and provide tips to apply quality control to each step of the procedure.     

Publishing SNP Genotypes of Human Embryonic Stem Cell Lines: Policy Statement of the International Stem Cell Forum Ethics Working Party

Novel methods and associated tools permitting individual identification in publicly accessible SNP databases have become a debatable issue. There is growing concern that current technical and ethical safeguards to protect the identities of donors could be insufficient. In the context of human embryonic stem cell research, there are no studies focusing on the probability that an hESC line donor could be identified by analyzing published SNP profiles and associated genotypic and phenotypic information. We present the International Stem Cell Forum (ISCF) Ethics Working Party's Policy Statement on "Publishing SNP Genotypes of Human Embryonic Stem Cell Lines (hESC)". The Statement prospectively addresses issues surrounding the publication of genotypic data and associated annotations of hESC lines in open access databases. It proposes a balanced approach between the goals of open science and data sharing with the respect for fundamental bioethical principles (autonomy, privacy, beneficence, justice and research merit and integrity).     

胚胎干细胞用于药物及其他化合物筛选的研究进展

胚胎干细胞 (Em bryonic stem cell,ES cell)用于药物及其他化合物的体外筛选 ,称为胚胎干细胞体外测试 (Embryonic stem cell test,EST) ,通过 EST可以把药物等化合物分为三类 :无毒性、弱毒性和强毒性。与其他方法相比 ,EST具有很大优点 :(1)无须牺牲大量怀孕动物。(2 )不用担心对动物或人体的巨大副作用。(3)由于胚胎干细胞在体外分化成多种细胞的潜能 ,EST可用于分化过程中药物或其他化合物对发育过程造成的毒理学研究。(4)可与计算机等分析方法结合 ,因而具有更高的准确率和敏感性。 (5 )可以进行分子水平的定量研究。这些都使得EST在药物筛选中显示出巨大的发展前景。本文综述了 EST的发展、研究方法、现状及其展望。     

Lessons from the Embryonic Neural Stem Cell Niche for Neural Lineage Differentiation of Pluripotent Stem Cells

Pluripotent stem cells offer an abundant and malleable source for the generation of differentiated cells for transplantation as well as for in vitro screens. Patterning and differentiation protocols have been developed to generate neural progeny from human embryonic or induced pluripotent stem cells. However, continued refinement is required to enhance efficiency and to prevent the generation of unwanted cell types. We summarize and interpret insights gained from studies of embryonic neuroepithelium. A multitude of factors including soluble molecules, interactions with the extracellular matrix and neighboring cells cooperate to control neural stem cell self-renewal versus differentiation. Applying these findings and concepts to human stem cell systems in vitro may yield more appropriately patterned cell types for biomedical applications.     

HTS/HCS to Screen Molecules Able to Maintain Embryonic Stem Cell Self-Renewal or to Induce Differentiation: Overview of Protocols

Embryonic stem (ES) cells, combining self-renewal ability with wide range tissue-specific cell differentiation, represent one of the most powerful model systems in basic research, drug discovery and biomedical applications. In the field of drug development, ES cells are instrumental in high-throughput/content screening (HTS/HCS) for the evaluation of large compound libraries to test biological activity and toxic properties. Since it is a high priority to test new compounds in vitro, before starting animal and human treatments, there is an increasing demand for new in vitro models that can be used in HTS/HCS to facilitate drug development. In order to achieve this objective, several methods for ES cell self-renewal or differentiation have been evaluated to assess their compatibility with HTS/HCS. This review describes protocols used to screen molecules able to maintain self-renewal or to induce differentiation in ectodermal, mesodermal, endodermal, and their derivative cell lines.     

胚胎干细胞移植治疗缺血性心脏疾病的研究进展

缺血性心脏疾病是威胁人类健康的头号杀手之一。冠状动脉阻塞引起心肌梗死,伴随心肌细胞大量死亡,损失的心肌细胞将被没有收缩功能的疤痕组织所替代,最终导致心力衰竭。近年来,移植外源性干细胞替代受损心肌的治疗策略得到人们越来越多的关注,并取得诸多进展。其中,胚胎干细胞具有无限增殖和多向分化的特点,在向心肌细胞分化、与宿主心肌细胞整合和心肌电信号传导方面具有优势,因此,在移植治疗心肌梗死方面具有广阔的应用前景。然而,胚胎干细胞最终应用于临床治疗晚期心脏疾病仍面临许多问题。本文就胚胎干细胞及其来源的细胞移植应用于缺血性心脏疾病治疗的研究进展作一综述。