转染组织纤溶酶原激活物及内皮型一氧化氮合酶基因的内皮细胞和平滑肌细胞共同种植于人工血管对内膜增生的影响

背景：前期研究表明,双层细胞种植能有效提高内皮细胞保留率,将组织纤溶酶原激活物基因转染到内皮细胞中能提高其细胞溶解纤维蛋白的能力。目的：采用双细胞种植及修饰内皮的组织纤溶酶原激活物基因提高内皮细胞保留率和抗栓能力,通过内皮型一氧化氮合酶基因调控平滑肌细胞的增殖,观察对小口径人工血管通畅率的影响。方法：以4种不同组合细胞（内皮细胞＋平滑肌细胞SMC,内皮细胞/组织纤溶酶原激活物＋平滑肌细胞,内皮细胞＋平滑肌细胞/内皮型一氧化氮合酶,内皮细胞/组织纤溶酶原激活物＋平滑肌细胞/内皮型一氧化氮合酶）种植在PTFE管腔面。将新西兰大白兔随机分成4组,4种人工血管经旁路分别移植在4组兔的腹主动脉上。结果与结论：移植后60d,种植内皮细胞＋平滑肌细胞组和内皮细胞＋平滑肌细胞/内皮型一氧化氮合酶组内膜厚度无明显差异（P〉0.05）。与内皮细胞/组织纤溶酶原激活物＋平滑肌细胞/内皮型一氧化氮合酶组相比,未转染内皮型一氧化氮合酶组（内皮细胞/组织纤溶酶原激活物＋平滑肌细胞）内膜明显增厚（P〈0.05）;未转染组织纤溶酶原激活物组（内皮细胞＋平滑肌细胞/内皮型一氧化氮合酶）内膜较薄（P〈0.05）。提示组织纤溶酶原激活物基因转染可以促进血管内膜增生导致血管狭窄,但同时转入内皮型一氧化氮合酶基因可以抑制组织纤溶酶原激活物的促进平滑肌细胞增殖及内膜增生的作用。     

内皮型一氧化氮合酶基因转染对移植人工血管内膜增生的作用

目的:平滑肌细胞增殖移行和血小板激活导致血栓形成是移植血管再狭窄的主要原因,一氧化氮可以抑制上述生物反应,但内皮型一氧化氮合酶基因转染是否抑制种植了平滑肌细胞的人工血管内膜增生还未得到证实.实验拟进一步观察内皮型一氧化氮合酶基因转染对种植平滑肌细胞的人工血管内膜增生的影响.方法:实验于2006-04/2007-05在西安交通大学医学院中心实验室及分子生物学实验室完成.①实验材料:1月龄新西兰大白兔1只,用来获取平滑肌细胞.成年新西兰大白兔18只,随机数字表法分成3组,每组6只.正常细胞组移植未种植细胞的人工血管;LacZ转染组移植种植转染lacZ的平滑肌细胞的人工血管,内皮型一氧化氮合酶转染组移植种植内皮型一氧化氮合酶的平滑肌细胞的人工血管.②实验方法:构建含有报道基因lacZ和内皮型一氧化氮合酶基因的假型反转录病毒载体小鼠白血病病毒/疱疹性口炎病毒G糖蛋白,并转染平滑肌细胞.将转染了基因的细胞种植在人工血管上,并用血管旁路移植的方法植入兔腹主动脉.③实验评估:测定转染内皮型一氧化氮合酶基因及LacZ基因细胞培养上清中一氧化氮含量.血管植入30,100 d 后X-gal染色及苏木精-伊红染色观察人工血管上的平滑肌细胞,同时显微镜下测量每段血管内膜增生的厚度.结果:纳入成年新西兰大白兔18只,均进入结果分析.①内皮型一氧化氮合酶转染组一氧化氮含量明显高于未转染的正常细胞组(P ＜ 0.05).平滑肌细胞转染lacZ基因后经X-gal染色,倒置显微镜下可见转染了基因的细胞被染成蓝色.②血管植入30 d,与正常细胞组比较,LacZ转染组和内皮型一氧化氮合酶转染组内膜厚度差异无显著性(P ＞ 0.05);100 d后,内皮型一氧化氮合酶转染组内膜厚度与正常细胞组无明显差异,与LacZ转染组相比较,差异显著(P ＜ 0.05).结论:内皮型一氧化氮合酶基因转染抑制了种植平滑肌细胞的人工血管内膜增生.     

内皮型一氧化氮合酶基因转染对移植人工血管内膜增生的作用

背景：平滑肌细胞增殖移行和血小板激活导致血栓形成是移植皿管再狭窄的主要原因，一氧化氮可以抑制上述生物反应，但内皮型一氧化氮合酶基因转染是否可以抑制种植平滑肌细胞的人工血管内膜增生还未得到证实。 目的：拟进一步观察内皮型一氧化氮合酶基因转染对种植平滑肌细胞的人工血管内膜增生的影响。 设计、时间及地点：重复观察测量，于2006-04／2007-05在西安交通大学医学院中心实验室及分子生物学实验室完成。 材料：1月龄新西兰大白兔1只，用来获取平滑肌细胞。成年新西兰大白兔18只．随机分成3组，正常对照组植入未转染的人工血管．LacZ转染组植入种植转染lacZ的平滑肌细胞的人工血管，内皮型一氧化氮合酶转染组植入种植内皮型一氧化氮合酶的平滑肌细胞的人工血管。6只/组。 方法：构建含有报道基因lacZ和内皮型一氧化氮合酶基因的假型反转录病毒载体小鼠白血病病毒/疱疹性口炎病毒G糖蛋白，并转染平滑肌细胞。将转染了基因的细胞种植在人工血管上，并用血管旁路移植的方法植入兔腹主动脉。 主要观察指标：瓜氨酸法检测细胞培养上清中一氧化氮含量。移植血管内膜X-gal染色观察，种植的平滑肌细胞为蓝色，而内源性细胞为红色。显微镜下测量血管内膜增生厚度。 结果：18只兔均进入结果分析。内皮型一氧化氮合酶转染组一氧化氮含量明显高于正常对照组（P〈0．05）。转染lacZ基因的平滑肌细胞经X-gal染色呈蓝色。血管平滑肌细胞植入30d，各组内膜厚度基本相似（P〉0．05）：植入100d．正常对照组与内皮型一氧化氮合酶转染组内膜厚度基本相似（P〉0．05），两组明显均低于lacZ转染组（P〈0．05）。 结论：内皮型一氧化氮合酶基因转染可抑制种植平滑肌细胞的人工血管内膜增生。     

内皮型一氧化氮合酶基因转染对移植人工血管内膜增生的作用

目的：平滑肌细胞增殖移行和血小板激活导致血栓形成是移植血管再狭窄的主要原因，一氧化氮可以抑制上述生物反应，但内皮型一氧化氮合酶基因转染是否抑制种植了平滑肌细胞的人工血管内膜增生还未得到证实。实验拟进一步观察内皮型一氧化氮合酶基因转染对种植平滑肌细胞的人工血管内膜增生的影响。 方法：实验于2006-04／2007—05在西安交通大学医学院中心实验室及分子生物学实验室完成。①实验材料；1月龄新西兰大白兔1只，用来获取平滑肌细胞。成年新西兰大白兔18只，随机数字表法分成3组，每组6只。正常细胞组移植未种植细胞的人工血管；LacZ转染组移植种植转染lacZ的平滑肌细胞的人工血管，内皮型一氧化氮合酶转染组移植种植内皮型一氧化氮合酶的平滑肌细胞的人工血管。②实验方法：构建含有报道基因lacZ和内皮型一氧化氮合酶基因的假型反转录病毒载体小鼠白血病病毒，疱疹性口炎病毒G糖蛋白，并转染平滑肌细胞。将转染了基因的细胞种植在人工血管上，并用血管旁路移植的方法植入兔腹主动脉。③实验评估：测定转染内皮型一氧化氮合酶基因及LacZ基因细胞培养上清中一氧化氮含量。血管植入30，100d后X—gal染色及苏木精一伊红染色观察人工血管上的平滑肌细胞，同时显微镜下测量每段血管内膜增生的厚度。 结果：纳入成年新西兰大白兔18只，均进入结果分析。①内皮型一氧化氮合酶转染组一氧化氮含量明显高于未转染的正常细胞组（P〈0．05）。平滑肌细胞转染lacZ基因后经X—gal染色，倒置显微镜下可见转染了基因的细胞被染成蓝色。②血管植入30d，与正常细胞组比较，LacZ转染组和内皮型一氧化氮合酶转染组内膜厚度差异无显著性（P〉0．05）；100d后，内皮型一氧化氮合酶转染组内膜厚度与正常细胞组?     

双细胞种植改善人工血管内皮细胞的保留率

背景: 前期研究表明,在人工血管内壁种植内皮细胞,使其早期快速内皮化,可以改善移植血管的通畅性,但种植的单层内皮细胞往往黏附力差,在血流的冲击下容易脱落.目的: 采用血管内皮细胞和平滑肌细胞双层种植方法,提高人工血管腔面内皮细胞的保存率.方法: 采用标准酶分离技术和细胞培养技术分离培养兔内皮细胞.采用组织贴块法分离培养兔平滑肌细胞.并分别以lacZ和GFP基因转染内皮细胞及平滑肌细胞.双层细胞种植组在聚四氟乙烯人工血管管腔面先后种植平滑肌细胞和内皮细胞,以单纯种植血管内皮细胞为对照.在体外将受试的人工血管接入作者设计的灌流模型下灌注2 h,计算比较灌注前后受试标本内皮细胞密度.体内实验,将人工血管植入兔子体内7 d,分别测定内皮细胞保留率.结果与结论: 灌注2 h后,单纯内皮细胞种植组细胞保留率为0.39±0.04,而双层细胞种植组内皮细胞保留率为0.73±0.07,双层细胞种植组细胞保存率明显高于单纯内皮细胞种植组(P<0.01).人工血管植入兔体内7 d,单纯内皮细胞种植组内皮细胞保留率为0.63±0.10,双层细胞种植组内皮细胞保留率为0 95±0.06,两组间差异有显著性意义(P<0.05).结果证实在内皮细胞和人工血管壁之间种植平滑肌细胞在体外和体内均可提高内皮细胞的保存率.     

组织型纤溶酶原激活因子构建及其在人脐静脉内皮细胞的表达活性

背景组织型纤溶酶原激活因子被认为是血管系统内初期血栓清除的关键酶.目的构建pcDNA3.1(+)组织型纤溶酶原激活因子真核表达载体转染人脐静脉内皮细胞,观察外源性组织型纤溶酶原激活因子的表达情况.设计随机对照实验.单位中南大学湘雅二医院及中国医学遗传学国家重点实验室.材料实验于2002-09/2003-06在中国医学遗传学国家重点实验室完成.脐静脉内皮细胞取自中南大学湘雅二医院健康产妇分娩后胎盘脐带,pcDNA3.1为SmithKline Beecham公司赠送.方法构建真核表达载体pcDNA3.1(+)组织型纤溶酶原激活因子,并将pcDNA3.1(+)组织型纤溶酶原激活因子转入人脐静脉内皮细胞,用酶联免疫吸附法定量检测转基因后组织型纤溶酶原激活因子蛋白表达情况、发色底物法检测外源性组织型纤溶酶原激活因子活性.以转pcDNA3.1(+)组织型纤溶酶原激活因子基因人脐静脉内皮细胞为观察对象,未转pcDNA3.1(+)组织型纤溶酶原激活因子基因人脐静脉内皮细胞作为对照.主要观察指标组织型纤溶酶原激活因子蛋白定量及活性测定结果.结果①组织型纤溶酶原激活因子蛋白定量表达结果为568.6 ng/106细胞/24 h,未转pcDNA3.1(+)组织型纤溶酶原激活因子的人脐静脉内皮细胞测得为17.8 ng/106细胞/24 h.②组织型纤溶酶原激活因子活性为108.8 IU/106细胞/24 h,未转pcDNA3.1(+)组织型纤溶酶原激活因子的人脐静脉内皮细胞测得为5.6IU/106细胞/24 h.结论pcDNA3.1(+)组织型纤溶酶原激活因子转染人脐静脉内皮细胞后,外源性组织型纤溶酶原激活因子基因获有效表达,为pcDNA3.1(+)组织型纤溶酶原激活因子转入人体细胞确立了有效依据.     

内皮型一氧化氮合酶基因转染对血管损伤后新生内膜增生的影响

背景:一氧化氮能够抑制血管平滑肌细胞的迁移和增殖,而一氧化氮合酶是其合成的关键酶,有关一氧化氮合酶基因体内转染对平滑肌细胞及动脉粥样硬化血管损伤后内膜增生影响少有报道。目的:观察内皮型一氧化氮合酶(endothelial nitric oxide synthase,eNOS)基因体内局部转染对动脉粥样硬化大鼠血管损伤后新生内膜增生的抑制作用。方法:建立动脉粥样硬化Wistar大鼠颈动脉球囊损伤模型,建模后随机分成空白对照组、AdCMV-lacz对照组和AdCMV-eNOS组,分别将PBS,AdCMV-lacz和AdCMV-eNOS体内转染至以上3组大鼠的损伤血管壁。转染2周后培养并鉴定损伤局部平滑肌细胞,并用RT-PCR法检测各组损伤及转染后血管平滑肌细胞eNOS mRNA的表达,同时观察转染后不同时期新生内膜增生的影响。结果与结论:AdCMV-eNOS组的颈总动脉血管平滑肌细胞可表达eNOS mRNA。3组大鼠转染后1和3个月,AdCMV-eNOS组内膜/中膜面积比值低于空白对照组和AdCMV-lacz对照组(P<0.01)。结果显示,eNOS基因体内转染损伤后血管可以抑制血管新生内膜增生,减少再狭窄发生率。     

内皮型一氧化氮合酶基因转染对血管损伤后新生内膜增生的影响

背景：一氧化氮能够抑制血管平滑肌细胞的迁移和增殖,而一氧化氮合酶是其合成的关键酶,有关一氧化氮合酶基因体内转染对平滑肌细胞及动脉粥样硬化血管损伤后内膜增生影响少有报道。目的：观察内皮型一氧化氮合酶（endothelial nitric oxide synthase,eNOS）基因体内局部转染对动脉粥样硬化大鼠血管损伤后新生内膜增生的抑制作用。方法：建立动脉粥样硬化Wistar大鼠颈动脉球囊损伤模型,建模后随机分成空白对照组、AdCMV-lacz对照组和AdCMV-eNOS组,分别将PBS,AdCMV-lacz和AdCMV-eNOS体内转染至以上3组大鼠的损伤血管壁。转染2周后培养并鉴定损伤局部平滑肌细胞,并用RT-PCR法检测各组损伤及转染后血管平滑肌细胞eNOS mRNA的表达,同时观察转染后不同时期新生内膜增生的影响。结果与结论：AdCMV-eNOS组的颈总动脉血管平滑肌细胞可表达eNOS mRNA。3组大鼠转染后1和3个月,AdCMV-eNOS组内膜/中膜面积比值低于空白对照组和AdCMV-lacz对照组（P〈0.01）。结果显示,eNOS基因体内转染损伤后血管可以抑制血管新生内膜增生,减少再狭窄发生率。     

三七总皂甙对血管内皮产生组织型纤溶酶原激活物的影响

三七总皂甙对血管内皮产生组织型纤溶酶原激活物的影响刘青，邓漪平血管内皮细胞（ＥＣ）合成和分泌的组织型纤溶酶原激活物（ｔ－ＰＡ）能激活血液中的纤溶酶原转变为纤溶酶，后者降解构成血栓骨架的纤维蛋白，从而防止血栓生成，ｔ－ＰＡ是机体溶纤机制的关键酶。曾报道...     

内皮型一氧化氮合酶与血管结构及功能的相关性

目的:应用内部核糖体进入位点构建携带内皮型一氧化氮合酶和血管内皮生长因子的双基因表达载体,研究外源性基因内皮型一氧化氮合酶和血管内皮生长因子在人脐静脉内皮细胞ECV304中的转染表达,探讨内皮型一氧化氮合酶与血管结构及功能的相关性。方法:实验于2003-12/2004-12在南京鼓楼医院科研部完成。将Phcmvsp1a-enos中内皮型一氧化氮合酶基因和PcDNA-vegf中血管内皮生长因子基因定向克隆到真核表达载体PcDNA-ires中,构建重组质粒PcDNA-enos-ires-vegf,经酶切,聚合酶链反应扩增和部分DNA测序分析证实后,转染人脐静脉内皮细胞,硝酸还原酶法检测转染后细胞中一氧化氮和一氧化氮合酶活性,免疫组化和荧光双标记及westernblotting检测转染后细胞蛋白水平的表达,Trizol提取总RNA,反转录-聚合酶链反应测定转染后细胞mRNA水平的表达。结果:成功构建携带内皮型一氧化氮合酶和血管内皮生长因子的双基因表达载体PcDNA-enos-ires-vegf,双基因内皮型一氧化氮合酶和血管内皮生长因子在人脐静脉内皮细胞基因组中获得整合及表达。重组基因PcDNA-enos-ires-vegf组与对照组PcDNA-enos在一氧化氮含量和一氧化氮合成酶活性的表达差异无显著性意义。PcDNA-enos-ires-vegf转染细胞后转染效率为30%～40%。结论:双基因表达载体PcD     

Phenotypic overlap between hematopoietic cells with suggested angioblastic potential and vascular endothelial cells

The existence of angioblast-like circulating endothelial progenitor cells (EPC) in adult humans has been suggested recently. Their role in postnatal angiogenesis is under intensive investigation. Discrimination between the supposed angioblasts (AC133(+)/FLK-1(+)/CD34(+)) and mature endothelial cells (ECs) is complicated by the fact that subsets of hematopoietic cells express markers similar to those of ECs. Among these, monocytes/macrophages and monocyte-derived dendritic cells (DCs) are more differentiated hematopoietic cell populations. They show a wide phenotypic overlap with particularly sinusoidal and microvascular ECs. Furthermore, under local angiogenic growth conditions, monocytes or monocyte precursors or immature DCs may differentiate into endothelial-like cells (ELC). Initial evidence suggests an endothelium-independent revascularization potential carried by macrophages. These macrophages have been shown to form "tunnel-like structures" in ischemic regions. Future studies will need to address the question of whether monocyte-/dendritic cell-derived ELC can develop a similar functional behavior in vasoregulation, coagulation, and fibrinolysis, as described for vascular ECs, and thus may contribute to neoangiogenesis by a direct vessel-forming role.     

In vitro differentiation of bone marrow derived porcine mesenchymal stem cells to endothelial cells

Mesenchymal stem cells (MSCs) hold potential for the regeneration of damaged tissues in cardiovascular diseases. In this study, we investigated the potential of porcine MSCs to differentiate into endothelial cells (ECs) in vitro. The cultured bone marrow‐derived cells were CD11b^–CD34^–CD44⁺CD45^–CD90⁺ and showed mesodermal lineage differentiation, which is characteristic of MSCs. The MSCs were induced to differentiate into ECs using endothelial growth medium (EGM), with and without high concentrations of VEGF (EGM + VEGF; 50 ng/ml). Endothelial basal medium (EBM) without growth factors served as the control. The EC differentiation was assessed by the presence of vWF, ability to take up acetylated LDL, in vitro angiogenesis assay, flow cytometry and qPCR of EC markers vWF, VE‐cadherin, PECAM‐1, VEGF‐R1 and VEGF‐R2 after 10 days of stimulation. Cells cultured in EGM + VEGF medium demonstrated higher amounts of DiI‐AcLDL‐positive cells and enhanced the presence of vWF (90%), VE‐Cadherin‐ (60%) and PECAM‐1 (48%)‐positive cells, than in EBM. These cells showed profuse sprouting of capillary tubes and closed polygon formation in the angiogenesis assay. There was 1.5–2‐fold increase in the mRNA expression of endothelial markers in the cells stimulated with EGM + VEGF medium when compared to control. The results demonstrate the ability of porcine MSCs to differentiate into ECs under in vitro inducing conditions. The differentiated cells would provide new options for re‐endothelialization following interventional procedures and tissue engineering. Copyright © 2012 John Wiley & Sons, Ltd.     

Vascular endothelial growth factor overexpression increases vascularization by murine but not human endothelial cells in cultured skin substitutes grafted to athymic mice

Cultured skin substitutes (CSS) consisting of fibroblasts, keratinocytes, and biopolymers are an adjunctive treatment for large burns. Because CSS lack a vascular plexus, they vascularize more slowly than split-thickness autografts. Previously, CSS were prepared with dermal microvascular endothelial cells (ECs), which formed vascular analogs at a low frequency but did not contribute to increased vascularization after grafting. The present study addressed whether keratinocytes genetically modified to overexpress vascular endothelial growth factor (VEGF), an endothelial cell mitogen, could improve the persistence and organization of ECs in CSS. CSS were prepared with control or VEGF-modified keratinocytes, with (CSS + ECs) or without added ECs, and were grafted to full-thickness wounds in athymic mice. Elevated VEGF expression was detected in VEGF-modified CSS and CSS + ECs compared with controls, but no significant difference in EC density in vitro was observed. After grafting, VEGF-modified CSS and CSS + ECs showed enhanced vascularization, and organization of human ECs into multicellular structures in CSS + ECs was observed. However, VEGF overexpression did not significantly enhance the proliferation of human ECs, suggesting that other factors may be required. Improved persistence and organization of human ECs in vitro will likely be required for their participation in vascularization of CSS + ECs after grafting.     

血管内皮祖细胞鉴定及其促血管新生机制的研究进展

血管内皮细胞(endothelial cells, ECs)既往被认为在出生后血管新生中发挥主要作用。1997年Asahara等从外周血分离出表达CD34抗原的单个核细胞,即血管内皮祖细胞(endothelial progenitor cells,EPCs)。EPCs是一类具有促血管生成能力的干细胞总称,尚未发现特异性免疫表型,故主要根据具有形成血管的功能鉴定。目前一般认为,EPCs来源于骨髓和外周血管壁,其中能分化为ECs者被称为内皮集落形成细胞(endothelial colony forming cells,ECFCs)。当组织缺血或损伤时,来自骨髓的EPCs被组织释放的损伤信号动员后进行迁移和归巢。活化的EPCs通过旁分泌作用招募更多的局部ECFCs和ECs来形成微血管,进而促进组织修复。因此,对EPCs的深入研究有助于临床上治疗性血管新生相关研究的进行和方法的发展。     

Corneal endothelial cells are protected from apoptosis by gene therapy

Corneal grafting is the most prevalent form of transplantation. Corneal endothelial cells (ECs), which form a monolayer of the cornea with minimal proliferative potential, are pivotal for maintenance of corneal clarity. Loss of EC viability and apoptosis leads to graft failure posttransplantation and reduces the quality of donor corneas in storage, such that up to 30% do not meet selection criteria and must be discarded. The current study investigates antiapoptotic effects of transduced mammalian Bcl-x(L) and baculoviral p35 on human ECs. Multiple apoptotic cell features are observed while inducing apoptosis either via the extrinsic (death receptor) or intrinsic (mitochondrial) apoptotic pathway. Human ECs were studied under three experimental conditions: (1) as an immortalized cell line, (2) as primary cells, and (3) in an intact cornea. Interestingly, in primary EC suspensions, Bcl-x(L) was protective against apoptosis mediated via both pathways. However, p35 was significantly more protective against apoptosis mediated via the intrinsic pathway compared with Bcl-x(L). Our results provide critical insight into the role of apoptotic pathways in the maintenance of EC viability and the efficacy with which these protective proteins exert their effect. These observations could form the basis for future applications of antiapoptotic gene therapy to corneal preservation aiming to reduce both graft failure after transplantation as well as donor corneal damage during storage.     

Co‐transplantation of Wharton's jelly mesenchymal stem cell‐derived osteoblasts with differentiated endothelial cells does not stimulate blood vessel and osteoid formation in nude mice models

A major challenge in bone tissue engineering is the lack of post‐implantation vascular growth into biomaterials. In the skeletal system, blood vessel growth appears to be coupled to osteogenesis—suggesting the existence of molecular crosstalk between endothelial cells (ECs) and osteoblastic cells. The present study (performed in two murine ectopic models) was designed to determine whether co‐transplantation of human Wharton's jelly mesenchymal stem cell‐derived osteoblasts (WJMSC‐OBs) and human differentiated ECs enhances bone regeneration and stimulates angiogenesis, relative to the seeding of WJMSC‐OBs alone. Human WJMSC‐OBs and human ECs were loaded into a silicate‐substituted calcium phosphate (SiCaP) scaffold and then ectopically implanted at subcutaneous or intramuscular sites in nude mice. At both subcutaneous and intramuscular implantation sites, we observed ectopic bone formation and osteoids composed of host cells when WJMSC‐OBs were seeded into the scaffold. However, the addition of ECs was associated with a lower level of osteogenesis, and we did not observe stimulation of blood vessel ingrowth. in vitro studies demonstrated that WJMSC‐OBs lost their ability to secrete vascular endothelial growth factor and stromal cell‐derived factor 1—including when ECs were present. In these two murine ectopic models, our cell‐matrix environment combination did not seem to be optimal for inducing vascularized bone reconstruction.     

Human progenitor‐derived endothelial cells vs. venous endothelial cells for vascular tissue engineering: an in vitro study

The isolation of endothelial progenitor cells from human peripheral blood generates a great hope in vascular tissue engineering because of particular benefit when compared with mature endothelial cells. We explored the capability of progenitor‐derived endothelial cells (PDECs) to line fibrin and collagen scaffolds in comparison with human saphenous and umbilical cord vein endothelial cells (HSVECs and HUVECs): (a) in a static situation, allowing definition of the optimal cell culture conditions with different media and cell‐seeding densities to check cell behaviour; (b) under shear stress conditions (flow chambers or tubular vascular constructs), allowing investigation of cell response and mRNA expression on both substrates by oligonucleotide microarray analysis and quantitative real‐time PCR. Well characterized PDECs: (a) could not be expanded adequately with the usual mature ECs culture media; (b) were able to colonize and grow on fibrin glue; (c) exhibited higher resistance to oxidative stress than HSVECs and HUVECs; (d) withstood physiological shear stress when lining both substrates in flow chambers, and their gene expression was regulated; (e) colonized a collagen‐impregnated vascular prosthesis and were able to sense mechanical forces. Our results provide an improved qualification of PDECs for vascular tissue engineering. Copyright © 2010 John Wiley & Sons, Ltd.