共查询到20条相似文献,搜索用时 21 毫秒
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Hematopoietic Stem Cells Contribute to Lymphatic Endothelium 总被引:1,自引:0,他引:1
Shuguang Jiang Alexis S. Bailey Devorah C. Goldman John R. Swain Melissa H. Wong Philip R. Streeter William H. Fleming 《PloS one》2008,3(11)
Background
Although the lymphatic system arises as an extension of venous vessels in the embryo, little is known about the role of circulating progenitors in the maintenance or development of lymphatic endothelium. Here, we investigated whether hematopoietic stem cells (HSCs) have the potential to give rise to lymphatic endothelial cells (LEC).Methodology/Principal Findings
Following the transfer of marked HSCs into irradiated recipients, donor-derived LEC that co-express the lymphatic endothelial markers Lyve-1 and VEGFR-3 were identified in several tissues. HSC-derived LEC persisted for more than 12 months and contributed to ∼3–4% of lymphatic vessels. Donor-derived LECs were not detected in mice transplanted with common myeloid progenitors and granulocyte/macrophage progenitors, suggesting that myeloid lineage commitment is not a requisite step in HSC contribution to lymphatic endothelium. Analysis of parabiotic mice revealed direct evidence for the existence of functional, circulating lymphatic progenitors in the absence of acute injury. Furthermore, the transplantation of HSCs into ApcMin/+ mice resulted in the incorporation of donor-derived LEC into the lymphatic vessels of spontaneously arising intestinal tumors.Conclusions/Significance
Our results indicate that HSCs can contribute to normal and tumor associated lymphatic endothelium. These findings suggest that the modification of HSCs may be a novel approach for targeting tumor metastasis and attenuating diseases of the lymphatic system. 相似文献10.
Stem cells: from epigenetics to microRNAs 总被引:11,自引:0,他引:11
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Measurement of Stem Water Potential of Young Plants Using a Hygrometer Attached to the Stem 总被引:3,自引:0,他引:3
A simple method was developed for the continuous non-destructivemeasurement of plant stem water potential. It consists of exposinga small section of stem vascular tissue and attaching to ita standard commercially available dewpoint hygrometer. Excellentagreement was found between water potential determined by thismethod, and that measured with a pressure-chamber on leavescovered with aluminium foil. Stem water potentials respondedwithin minutes to changes in radiation and transpiration. Resistanceto water uptake was found to be independent of the rate of transpiration. 相似文献
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为建立多顺反子质粒载体转染技术获得人脂肪干细胞(adipose stem cells,ASCs)来源的诱导多能干细胞(induced pluripotency stem cells,iPSCs),应用2A元件连接Oct4/Sox2/KLF4/c-Myc四因子基因,构建为单一开放阅读框的多顺反子质粒载体.使用该质粒对ASCs进行转染及重编程为iPSC.采用形态学观察、特异性抗体免疫荧光鉴定、体外拟胚体诱导分化和体内畸胎瘤形成等方法进行鉴定.结果显示,ASCs成功重编程为iPSCs,具有与人胚胎干细胞相似的形态学及多向分化潜能;通过拟胚体和畸胎瘤实验证实iPSCs能在体内外分化成三胚层细胞;DNA印迹实验显示质粒载体序列未整合至iPSCs基因组中.因此,通过多顺反子质粒载体重编程技术成功建立的人iPSCs具有多向分化潜能,可减免发生插入突变和免疫排斥问题,为iPSCs在遗传性或退行性疾病的治疗奠定了实验基础. 相似文献
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Early Responses of Excised Stem Segments to Auxins 总被引:2,自引:0,他引:2
PENNY PAULINE; PENNY DAVID; MARSHALL DAVID; HEYES J. K. 《Journal of experimental botany》1972,23(1):23-36
The elongation rate of lupin hypocotyl and pea stem segmentswas measured every minute after the addition of various auxinsand auxin precursors. After a latent period the growth-rateincreased to a peak, fell to a minimum, and with most compoundsincreased to a second maximum. Compounds used include indol-3yl-aceticacid (IAA), indol-3yl-acetamide, naphth-2yl-oxyacetic acid,naphth- lyl-acetamide, and indol-3yl butyric acid. The extensibilityof the cell walls of the lupin segments was measured with anInstron Universal Testing Instrument at intervals after theaddition of IAA and it was shown that the lag period beforethe extensibility increased was longer than that for the growth-rate. Kinetic studies were made of the effect of Actinomycin D onIAA-induced growth. RNA synthesis during the first 20 and 40min after IAA addition was also examined in segments exposedto labelled RNA precursors during these times. The results supportthe conclusion that RNA synthesis is not necessary for the initialaction of auxin on elongation. 相似文献