细胞移植中的基因修饰技术

基因治疗的发展已经取得了可喜的成果——将实验研究成果转化为临床治疗。基因修饰技术已被大量运用于细胞移植,但瓶颈是有效的基因传递系统。几种病毒载体已被用于转导终末期的分化细胞,近来的大部分成功的案例都是应用腺病毒相关载体。作为一种替代方法,人类胚胎干细胞和干细胞样体系已被建立用来产生组织特异性的基因修饰细胞。     

骨髓基质细胞在细胞移植与基因治疗中的应用

骨髓基质细胞是研究最广泛的成体干细胞,用于临床细胞移植与基因治疗有诸多优点,论述了具有多向分化潜能的骨髓基质细胞,应用于细胞移植与基因治疗中的研究现状及发展前景 。     

糖尿病治疗新进展——胰岛细胞移植

随着医学科学的发展和生物学技术的进步,胰岛细胞移植已经被认为是治疗1型糖尿病的一种有效方法。技术上首先要解决好移植物的来源、提取和储存。同时,将移植物导入体内的技术也在不断发展,介入放射学技术发挥了非常重要的作用。研究发现．移植后受体的高血糖明显降低,并能在较长时期保持在正常水平。但胰岛细胞移植后,同样面临移植排斥反应,而在应用免疫抑制剂后又可能引起肝小静脉病等不良反应。利用磁共振和光学成像对标记后的胰岛细胞进行显像,对移植后的胰岛细胞在活体内进行追踪．了解其分布和存活,对于长期监测其功能、改进移植技术和免疫调节方法也很重要。目前面临的问题终将逐一得到解决．胰岛细胞移植很有希望成为治愈糖尿病的方法。     

微囊化基因工程细胞移植的研究进展

微囊化基因工程细胞移植是将目的基因通过基因转染技术导入到靶细胞内,再将该细胞微囊化后植入受体体内,具有组织相容性好,避免了机体的排斥反应(免疫隔离),且微囊内的功能细胞可以长期存活,发挥其生物学效应。该技术使得异种组织细胞或基因工程细胞移植成为可能,在神经内分泌及代谢疾病等方面的研究取得了可喜的进展,具有广阔的应用前景。     

细胞移植治疗脑瘫的研究现状

小儿脑性瘫痪(简称脑瘫)是目前小儿时期最主要的神经运动功能伤残疾病,且终生存在。尽管有支持性医护,但是目前并没有效治疗的方法。近几年,许多实验室开展了利用干细胞移植治疗脑瘫动物模型的研究,并且报道说人脐血干细胞和间充质干细胞对于脑瘫是有治疗作用的。而神经干细胞也被用于移植治疗脑瘫动物模型,并被证明这些移植的神经干细胞能迁移至受损脑部并分化为神经元。本文就至今已发表的一些细胞移植治疗脑瘫的研究中所用到的细胞种类做一综述。     

供体细胞与哺乳动物体细胞核移植

哺乳动物体细胞核移植(克隆)技术在转基因动物生产、珍稀动物资源复原与保护、生物学基础研究等方面业已显示出重要的应用价值,而目前该技术还与诱导多能干细胞技术一同被认为是创制患者特异性多能干细胞,为再生医学临床"细胞治疗"提供素材的最佳手段。但是,体细胞克隆的效率仍不理想,关键机制还不清楚,严重制约了该技术的推广。因此,如何提高克隆效率已成为人们普遍关心的首要问题。在体细胞克隆技术所涉及的各环节中,供体细胞是影响克隆效率的最关键因素之一。该文从供体细胞的生物学因素和技术因素两方面进行了回顾,旨在为进一步探寻建立物种或供体细胞个性化准备方案,为提高动物克隆效率提供参考。     

细胞移植治疗脑瘫的研究现状

小儿脑性瘫痪（简称脑瘫）是目前小儿时期最主要的神经运动功能伤残疾病,且终生存在。尽管有支持性医护。但是目前并没有效治疗的方法。近几年,许多实验室开展了利用干细胞移植治疗脑瘫动物模型的研究,并且报道说人脐血干细胞和间充质干细胞对于脑瘫是有治疗作用的。而神经干细胞也被用于移植治疗脑瘫动物模型,并被证明这些移植的神经干细胞能迁移至受损脑部并分化为神经元。本文就至今已发表的一些细胞移植治疗脑瘫的研究中所用到的细胞种类做一综述。     

微流控芯片技术在细胞生物学研究中的应用进展

20世纪90年代以来,微流控芯片技术得到了快速发展。由于具有小型化、集成化、高通量、低消耗、分析快速等特点,微流控芯片作为一种新型的生物学研究平台,能够提供传统方法不具备的精细和可控制的细胞研究条件,在细胞生物学研究领域中得到了广泛关注。该文主要介绍其在细胞培养、分选、裂解、计数、凋亡检测、迁移、单细胞捕获、细胞间作用等方面的研究进展。     

Efficient and Innocuous Live‐Cell Delivery: Making Membrane Barriers Disappear to Enable Cellular Biochemistry

The confluence of protein engineering techniques and delivery protocols are providing new opportunities in cell biology. In particular, techniques that render the membrane of cells transiently permeable make the introduction of nongenetically encodable macromolecular probes into cells possible. This, in turn, can enable the monitoring of intracellular processes in ways that can be both precise and quantitative, ushering an area that one may envision as cellular biochemistry. Herein, the author reviews pioneering examples of such new cell‐based assays, provides evidence that challenges the paradigm that cell penetration is a necessarily damaging and stressful event for cells, and highlights some of the challenges that should be addressed to fully unlock the potential of this nascent field.     

Ultrastructural evidence for two-cell and three-cell neural pathways in the tentacle epidermis of the sea anemone Aiptasia pallida.

Sensory and ganglion cells in the tentacle epidermis of the sea anemone Aiptasia pallida were traced in serial transmission electron micrographs to their synaptic contacts on other cells. Sensory cell synapses were found on spirocytes, muscle cells, and ganglion cells. Ganglion cells, in turn, synapsed on sensory cells, spirocytes, muscle cells, and other neurons and formed en passant axo-axonal synapses. Axonal synapses on nematocytes and gland cells were not traced to their cells of origin, i.e., identified sensory or ganglion cells. Direct synaptic contacts of sensory cells with spirocytes and sensory cells with muscle cells suggest a local two-cell pathway for spirocyst discharge and muscle cell contraction, whereas interjection of a ganglion cell between the sensory and effector cells creates a local three-cell pathway. The network of ganglion cells and their processes allows for a through-conduction system that is interconnected by chemical synapses. Although the sea anemone nervous system is more complex than that of Hydra, it has similar two-cell and three-cell effector pathways that may function in local responses to tentacle contact with food.     

哺乳动物体细胞核移植中供体细胞的研究进展

在哺乳动物体细胞核移植中,供体细胞是影响其效率的主要因素之一。供体细胞的类型、细胞周期、细胞的培养代数、冷藏与冷冻处理,以及供体动物的性别、年龄等都可能影响核移植胚胎的发育。根据现有资料,简要综述了在哺乳动物体细胞核移植中有关供体细胞的研究进展。     

The role of glutamine, serum and energy factors in growth of enterocyte-like cell lines

Background: Glutamine is routinely added to most cell cultures. Glutamine has been found to be the preferential nutrient to the rapidly replicating intestinal mucosa, but whether this is a metabolic effect or due to other properties of this amino acid is not determined. To study the importance of glutamine on the growth of two enterocyte-like cell lines, the effects of depriving the media or supplementing it with glutamine were assessed in media with different serum and energy supplements. Methods: CaCo-2 and HT-29 cells were grown in serum-free medium, with fetal bovine or synthetic serum, and with or without glucose or galactose. The glutamine content was varied between 0 and 4 mM. All growth assays were performed in triplicate by counting in a hemocytometer. Results: Both cell lines were dependent of serum factors for growth, but displayed distinct requirements on glutamine supplementation. Glutamine was an obligate supplement with dose-dependent correlation to growth (r=0.87, p<0.01) for CaCo-2 cells cultured in synthetic, but not in fetal bovine serum. In HT-29 cells, the correlation between glutamine and growth was significant (r=0,68, p<0,05) only in fetal bovine serum in the absence of galactose. Conclusion: This study shows that glutamine has different growth stimulating effects on two enterocyte-like cell lines studied. This could reflect different modes of action of glutamine on proliferation and differentiation in an enterocyte cell population.     

Of mice, frogs and flies: generation of membrane asymmetries in early development

Embryonic development begins with cleavage of the fertilized egg. Cleavage comprises two major processes: cytokinesis and formation of a polarized epithelial cell layer. The focus of this review is comparison of the generation of membrane polarity during embryonic cleavage in three different developmental model systems. In mammalian embryos, as exemplified by analysis of the mouse, generation of distinct membrane domains is uncoupled from cleavage divisions and is initiated in a specific developmental phase, called compaction. In Xenopus laevis embryos, generation of polarized blastomeres occurs simultaneously with cytokinesis. The origin of specific membrane domains of X. laevis polar blastomeres, however, can be traced back to oogenesis. Finally, in Drosophila melanogaster, generation of polarized cells occurs at cellularization. The relevance of cell adhesion, cell junctions and cytocortical scaffolds will be discussed for each of the model systems. Despite enormous morphologic differences, the three models share many common features; in particular, many important molecular interactions are conserved.     

微囊化K562细胞生长周期及代谢特性的研究

以K562细胞为模型,分别进行微囊化和游离培养,运用流式细胞术考察两种培养体系下细胞周期和生长代谢变化;建立数学模型,模拟了两种培养体系下细胞的生长活性和代谢特性。实验发现：微囊化培养过程中的K562细胞处于DNA合成期（S期）的百分含量显著高于游离培养,并且细胞保持较高的增殖活性。模型计算表明,所建模型动力学参数能够很好地描述微囊化和游离两种培养体系下细胞的代谢情况;对细胞活性的理论计算表明,微囊化的细胞具有较高的增殖和代谢活性,同时细胞能够较长时间保持此活性;模型参数表明,两种培养体系下,葡萄糖对细胞生长的影响无显著差别 (k^Free_L≈k^APA_L),乳酸对游离培养细胞的生长具有明显抑制作用,但对微囊化培养细胞抑制作用较小(kFreeL>≈kAPAL)。     

Engineering Cardiac Cell Junctions In Vitro to Study the Intercalated Disc

Abstract

This review article discusses a recent work using engineered cardiac cells to study the function of the intercalated disc putting emphasis on mechanical and electrical coupling.     

Uniform straw-like cell architecture for three-dimensional cell–cell communication assay

ABSTRACT

We fabricated uniform straw-like cell architecture with central lumen using a suture thread within 1 h. The architecture consisting of cancer cells and mature adipocyte was used for cell–cell communication assay, although mature adipocyte could not form spontaneous multi-cellular spheroids. Using the system, it is possible to investigate three-dimensional cell–cell communication as an alternative to animal experiments.     

Perivascular cells for regenerative medicine

Mesenchymal stem/stromal cells (MSC) are currently the best candidate therapeutic cells for regenerative medicine related to osteoarticular, muscular, vascular and inflammatory diseases, although these cells remain heterogeneous and necessitate a better biological characterization. We and others recently described that MSC originate from two types of perivascular cells, namely pericytes and adventitial cells and contain the in situ counterpart of MSC in developing and adult human organs, which can be prospectively purified using well defined cell surface markers. Pericytes encircle endothelial cells of capillaries and microvessels and express the adhesion molecule CD146 and the PDGFRβ, but lack endothelial and haematopoietic markers such as CD34, CD31, vWF (von Willebrand factor), the ligand for Ulex europaeus 1 (UEA1) and CD45 respectively. The proteoglycan NG2 is a pericyte marker exclusively associated with the arterial system. Besides its expression in smooth muscle cells, smooth muscle actin (αSMA) is also detected in subsets of pericytes. Adventitial cells surround the largest vessels and, opposite to pericytes, are not closely associated to endothelial cells. Adventitial cells express CD34 and lack αSMA and all endothelial and haematopoietic cell markers, as for pericytes. Altogether, pericytes and adventitial perivascular cells express in situ and in culture markers of MSC and display capacities to differentiate towards osteogenic, adipogenic and chondrogenic cell lineages. Importantly, adventitial cells can differentiate into pericyte‐like cells under inductive conditions in vitro. Altogether, using purified perivascular cells instead of MSC may bring higher benefits to regenerative medicine, including the possibility, for the first time, to use these cells uncultured.