体外培养慢性粒细胞白血病患者骨髓间充质干细胞的生物学特性

背景：课题组从胎儿骨髓间充质干细胞的培养体系中鉴定出一类贴壁细胞,已证实此类细胞在单细胞水平可以向造血及内皮细胞分化。 目的：检测骨髓间充质干细胞的生物学特性,为慢性粒细胞白血病的治疗提供相关的依据。 方法：以慢性粒细胞白血病患者骨髓为研究对象,体外培养并扩增原始间充质干细胞,检测其BCR/ABL融合基因的表达、免疫学特性和生长曲线,使用RT-PCR和FISH的方法检测其BCR/ABL融合基因的表达情况。 结果与结论：慢性粒细胞白血病患者骨髓来源的间充质干细胞呈成纤维样生长,大部分细胞处于G0/G1期,并且高表达Flk1,CD13,CD29,CD44,用RT-PCR和FISH的方法能够检测出BCR/ABL融合基因的表达。提示慢性粒细胞白血病的白血病基因转化可能发生在比造血干细胞更高的骨髓间充质干细胞水平上,对慢性粒细胞白血病的疾病起源及干细胞移植治疗有重要的意义。     

红细胞生成素对慢性肾衰竭大鼠外周血内皮祖细胞的影响

目的 探讨红细胞生成素（EPO）对慢性肾衰竭大鼠外周血内皮祖细胞（EPC）数量和功能的影响。 方法 采用分阶段5/6肾切除制备大鼠慢性肾衰竭模型。实验动物按数字随机表法分为4组（均n = 7）：假手术组、慢性肾衰竭组（模型组）、30 U/kg EPO干预组（小剂量组）和50 U/kg EPO干预组（大剂量组）。大鼠皮下注射EPO 6周后,取其外周血分离培养EPC,并检测EPC数量及其增殖、黏附和形成血管结构的能力。 结果 与假手术组比较,慢性肾衰竭大鼠外周血EPC数量及其增殖、黏附与形成血管结构的能力均显著下降（均P < 0.05）。应用EPO治疗能显著增加慢性肾衰竭大鼠外周血EPC数量（P < 0.05）,改善外周血EPC增殖、黏附及形成血管结构的能力（均P < 0.05）,并且呈剂量依赖性。 结论 EPO可改善慢性肾衰竭大鼠外周血EPC的数量和功能。     

Tunica Interna Endothelial Cell Kinase Expression and Hematopoietic and Angiogenic Potentials in Cord Blood CD34+ Cells

Tunica interna endothelial cell kinase (TEK) is expressed in both hematopoietic and endothelial cells and plays a crucial role in hematopoiesis and angiogenesis in mouse development. In humans, however, little is known about the hematopoietic and angiogenic potentials of TEK-expressing cells in umbilical cord blood (CB) cells, which originate during the human fetal period. We therefore compared the hematopoietic and angiogenic abilities of CB CD34+TEK+ and CD34+TEK- cells by using a clonogenic assay and xenotransplantation into immunodeficient NOD/SCID mice. The results showed that colony-forming cells and cells capable of repopulating in NOD/SCID mice were present in both CD34+TEK+ and CD34+TEK- cells and that the hematopoietic activities of the cell types were similar. In contrast, the potential to differentiate into endothelial cells in vivo was greater in the CD34+TEK+ cells. All NOD/SCID mice engrafted with CD34+TEK+ cells had human CD31-expressing and VE-cadherin-expressing endothelial cells in the vessels of the ischemic muscles and/ or human endothelial cells expressing CD31, kinase-insert domain-containing receptor, and endothelial nitric oxide synthase in liver sinusoidal cells, whereas such endothelial cells were detected in only 3 of the 7 recipients engrafted with CD34+TEK- cells. This result has important implications in cell therapy using CB cells for treating hematopoietic disorders and vascular diseases.     

Sonic hedgehog信号通路对AGM区来源的成血-血管细胞增殖、迁移和分化作用

目的探讨Sonichedgehog（Shh）信号通路对小鼠主动脉-中肾-肾上腺（AGM）区来源的成血．血管细胞增殖、分化和迁移的影响。方法联合应用抗小鼠CD34、Flkl单克隆抗体（单抗）的磁珠，从孕11dBALB／c鼠胚胎AGM区分离培养成血-血管干细胞，并同时培养AGM区来源基质细胞，用流式细胞术对所分离细胞进行表型鉴定。用免疫组织化学法检测基质细胞表达Shh蛋白的情况；借助TransweU细胞共培养体系，观察在AGM的基质细胞共培养体系中，不同浓度的Shh活性肽及其单抗对成血．血管干细胞增殖、细胞周期、迁移及向内皮细胞定向分化的影响。结果AGM区基质细胞高表达Shh蛋白（阳性率高达90％以上），并可促进成血-血管干细胞增殖，其增殖效应可被10．00μg／mlShh单抗阻断；0．10-10．00μg／ml外源性Shh活性蛋白与AGM区基质细胞共培养的成血-血管干细胞，可使成血．血管干细胞长时间增殖，并促进细胞迁移，但并不诱导细胞凋亡与分化；而当0．10-10．00μ／ml外源性Shh活性蛋白作用于单独培养的成血-血管干细胞，细胞经过短时间增殖后，随后发生凋亡并向内皮细胞分化。结论Shh信号通路参与了成血-血管干细胞的增殖、分化、凋亡及迁移等生物学特性的调控，但其具体作用存在时空的差异，AGM区微环境对Shh信号通路具有整合和调试的作用。     

胚胎干细胞体外诱导分化为成血管血液干细胞的研究进展

成血管血液干细胞的概念早在20世纪就已经有人提出来,如今它的存在已经在小鼠和人的胚胎干细胞分化形成的类胚体中得到证实.在胚胎正常发育过程中,原始成血管血液干细胞具有分化形成血管内皮细胞和造血细胞2个谱系的双向分化潜能,是它们共同的前体细胞;而体外诱导分化胚胎干细胞形成成血管血液干细胞的模型为研究血管内皮细胞及造血细胞发育、分化过程和调控以及之间的关系提供了有效的途径.就近年这方面的一些研究成果作一综述. Abstract： The concept of hemangioblast was proposed a century ago. The existence of hemangioblasts has been demonstrated recently in vitro by differentiation of mouse and human embryonic stem (ES) cell into em-bryoid bodies(EBs). In the developing embryo, a common progenitor, termed "hemangioblast", generates both hematopoietic and endothelial cell lineages. The in vitro differentiation of embryonic stem cells to hemangioblast is a powerful approach for studying the commitment of the hematopoietic and endothelial lineages. This review will summarize recent development in the studies on hemangioblast.     

Origin of Hematopoietic Progenitors during Embryogenesis

It has been widely accepted that hematopoietic and endothelial cell lineages diverge from a common progenitor referred to as the hemangioblast. Recently, analyses of the potential of progenitor cells purified from mouse embryos as well as embryonic stem cells differentiating in vitro resolved intermediate stages between mesodermal cells and committed precursors for hematopoietic and endothelial cell lineages. There are two distinct hematopoietic cell lineages which have different origins, i.e., primitive hematopoietic lineage derived from mesoderm or hemangioblasts and definitive hematopoietic lineage derived from endothelial cells. The endothelium is suggested to provide a milieu in which the definitive hematopoietic lineage acquires multiple potentials.     

成血管血液干细胞特化形成相关基因的研究进展

在鼠和人的胚胎发生过程中,血细胞紧邻内皮细胞发育.在卵黄囊血岛、胚内腹侧中胚层-副主动脉层/主动脉性腺-中肾(para aortic splanchnopleura/aorta gonad mesonephros,PAS/AGM)     

Bcr/Abl融合基因阳性、Flk1+CD34-慢性粒细胞性白血病干细胞的分离纯化及其生物学特性的研究

目的分离慢性粒细胞白血病(ChronicMyelogenousLeukemia,CML)患者骨髓中表达BCR/ABL肿瘤基因的细胞亚群,并研究其生物学特性。方法淋巴细胞分离液分离CML患者骨髓单个核细胞,免疫磁珠分选CD45-、GlyA-及CD34-细胞,极限稀释法获得单克隆细胞,流式细胞术鉴定其免疫表型,体外定向诱导分化检测其干细胞特性,并检测其Bcr/Abl融合基因的表达情况。结果CML患者骨髓源单克隆扩增细胞不表达造血细胞和内皮细胞的特征性表型,但Bcr/Abl融合基因阳性;诱导后的细胞能同时向造血细胞及血管内皮细胞分化。结论Bcr/Abl融合基因的产生至少发生在比造血干细胞更为早期的血液血管干细胞水平上,即CML至少起源于血液血管干细胞。