百里醌对血管生成及胰腺癌生长的影响

目的: 探讨百里醌对血管生成和胰腺癌生长的影响及其机制。方法: 采用贴壁选择法培养人脐血内皮祖细胞(EPCs),细胞免疫组化检验细胞中血管内皮生长因子受体-2(VEGFR-2)、VIII因子和 CD34表达,证实细胞属性;观察不同浓度(10 nmol/L、20 nmol/L和40 nmol/L)百里醌对EPCs小管形成的影响;不同浓度(20 μmol/L、40 μmol/L和80 μmol/L)百里醌作用人胰腺癌细胞株PANC-1后,Western blotting检测胰腺癌细胞中血管内皮生长因子(VEGF)表达的变化;建立裸鼠胰腺癌原位移植瘤模型,分成对照组和百里醌组,实验结束后观察百里醌对裸鼠胰腺癌生长的抑制作用;免疫组织化学法检测裸鼠胰腺肿瘤组织中Ki-67、CD34和VEGF的阳性表达。结果: 体外成功培养出人脐血EPCs,百里醌可显著抑制体外EPCs小管形成;并抑制体外人胰腺癌PANC-1细胞中VEGF的表达;与对照组相比较,百里醌可明显抑制荷瘤裸鼠中胰腺肿瘤生长,并下调Ki-67、CD34和VEGF在胰腺肿瘤组织中的阳性表达。结论: 百里醌可抑制体内外血管生长,有望作为治疗胰腺癌的血管抑制药物。     

脐血血管内皮祖细胞的分离和诱导分化

目的 从脐血中分离内皮祖细胞，诱导其向内皮细胞分化，研究内皮祖细胞的生物学特性和诱导分化条件。方法 从新鲜脐血中纯化的CD133^ 细胞接种于添加了VEGF、bFGF、IGF—1的M199培养液中，观察梭形贴壁细胞的出现时间和特异性细胞标志。结果 培养3—4d可观察到梭形贴壁细胞，14d左右可形成索条状结构，贴壁细胞表达血管内皮细胞特异性标志VE-cadherin,vWF,UEA-1和VEGFR-2。结论 脐血中含有内皮祖细胞，在一定的条件下，可分化为内皮样细胞。     

CD133+卵巢癌干细胞样细胞在血管内皮细胞中的分化

背景：大量研究证实,新生血管形成在肿瘤的生长、浸润以及转移过程中发挥重要作用。 目的：探讨CD133+卵巢癌干细胞样细胞向血管内皮细胞分化的特点。 方法：通过无血清培养方法从卵巢癌A2780细胞株中成功诱导出CD133⁺卵巢癌干细胞样细胞,在体外接种于铺或不铺Matrigel基质胶的96孔板内,观察不同时间点CD133⁺卵巢癌干细胞样细胞和人脐静脉内皮细胞形成管腔样结构能力。通过裸鼠皮下移植实验,免疫荧光法观察CD133⁺卵巢癌干细胞样细胞在卵巢癌血管新生中的作用。 结果与结论：CD133⁺卵巢癌干细胞样细胞和人脐静脉内皮细胞(阳性对照)在未铺 Matrigel基质胶上并不能形成相应的管腔结构,且不表达内皮细胞标志物CD31,在Matrigel基质胶上能够形成相对稳定的管腔结构,CD31表达明显。CD133⁺卵巢癌干细胞样细胞接种裸鼠皮下成瘤后,可观察到肿瘤组织中有人源性CD31的表达。结果表明CD133⁺卵巢癌干细胞样细胞能够分化为血管内皮细胞,参与肿瘤血管重建。中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程     

大鼠骨髓内皮祖细胞促进神经胶质瘤生长

目的:探讨骨髓内皮祖细胞( EPCs)对神经胶质瘤的作用,为深入研究神经胶质瘤提供基础资料.方法:建立荷瘤裸鼠动物模型,裸鼠设计同体对照,实验组注射胶质瘤C6细胞与大鼠EPCs的等比混合细胞悬液,对照组注射C6细胞悬液,每隔2d观测并记录肿瘤生长情况;第27天处死动物,剥离肿瘤,观测肿瘤大小和质量,H-E及免疫组织化学显色,检测肿瘤组织内含CD31阳性细胞的管腔样结构的数目,反映肿瘤组织内微血管密度(MVD);免疫荧光观测EPCs是否参与神经胶质瘤血管新生.结果:细胞接种后第9天肉眼观察裸鼠皮下肿物,实验组肿物大小为(0.1±0.029)cm3,对照组(0.09±0.024)cm3,两组差异无统计学意义;之后肿瘤逐渐增大,第15天时实验组肿瘤(0.21±0.042)cm3大于对照组(0.17±0.026)cm3;第27天时处死动物,实验组肿瘤质量(17.56±1.30)g大于对照组(11.24±1.16)g.H-E染色显示,两组神经胶质瘤细胞较为密集,局部有血管样结构.免疫组织化学显色结果显示,实验组MVD值(30±1.2)个/视野多于对照组(18±1.01)个/视野.免疫荧光显示,肿瘤组织局部有大鼠骨髓EPCs.结论:骨髓EPCs能促进C6胶质瘤生长.     

血管内皮生长因子诱导的胶质瘤源性微血管内皮细胞体外三维成型特性

目的比较人脑胶质瘤源性微血管内皮细胞（GDMEC）和内皮细胞样细胞ECV304三维培养血管生成特性,探讨GDMEC在血管生成研究中的意义。方法采用免疫磁珠分选系统获得纯化的人脑GDMEC,以胶原为介质建立内皮细胞三维培养模型,比较观察GDMEC与ECV304细胞三维培养小管样结构（TLS）形成及不同浓度血管内皮生长因子（VEGF）对两种细胞TLS形成的诱导作用。结果所获GDMEC细胞纯度达98％,可连续传代培养。GDMEC的TLS形成数显著多于同数量、同时相点ECV304细胞的TLS形成数量。VEGF在体外对GDMEC有显著的促进TLS形成作用,且呈量-效和时-效关系;VEGF对ECV304细胞形成小管样结构的诱导作用弱。结论GDMEC在体外保持了内皮细胞特征和活跃的血管生成特性,对VEGF的反应性较ECV304好,因而GDMEC更适合体外血管生成研究。     

人脂肪干细胞促进小鼠随意型皮瓣血管的新生

背景：脂肪干细胞是从脂肪组织中分离提取的一种具有多向分化潜能的干细胞,对缺血性疾病的治疗有积极作用。 目的：观察局部移植人来源脂肪干细胞对小鼠随意型皮瓣成活能力及血管新生效应的影响。 方法：体外经分离、培养及传代健康成人脂肪干细胞。于SPF小鼠背部设计蒂在头侧的随意型皮瓣设为实验组,随后于皮瓣蒂部、中部、远端分3次注射脂肪干细胞悬液、并设置以同法注射等量PBS的小鼠作对照组。移植后7 d,计算各组皮瓣成活率。移植后14 d,取皮瓣组织,随机作冰冻切片CD31免疫荧光染色,荧光显微镜下观察皮瓣组织微血管分布情况,并对CM-Dil标记的脂肪干细胞示踪;ELISA法检测皮瓣组织中血管内皮生长因子水平;Western blot法检测皮瓣组织中基质细胞衍生因子1蛋白的表达。 结果与结论：与对照组相比,实验组小鼠背部随意皮瓣成活率明显提高,皮瓣组织中微血管数目明显增多,血管内皮生长因子分泌水平明显升高,基质细胞衍生因子1蛋白表达明显增多(P < 0.05)。结果证实,人脂肪干细胞局部移植到随意型皮瓣后,可上调血管内皮生长因子和基质细胞衍生因子1的表达,促进皮瓣的血管新生。中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程全文链接：     

内皮祖细胞在体外培养成血管样结构的初步观察

目的：探索体外培养脐血、外周血内皮祖细胞（EPCs）的方法，观察其形成血管样结构的可能性及条件。 方法： 采用贴壁选择法培养人脐血及兔外周血内皮祖细胞，光镜下观察细胞形态，用荧光显微镜、流式细胞仪分析贴壁细胞CD34、VEGFR-2、AC133、血管内皮钙粘素（VE-cadherin）的表达，DiI-ac-LDL 吞噬试验及Ⅷ因子免疫组化证实细胞属性。 结果： 体外成功培养出人脐血及兔外周血内皮祖细胞，形成条索状、管状结构，兔外周血EPCs分化较成熟，形成典型铺路石形状及血管样结构。 结论： 脐血、兔外周血内皮祖细胞可在体外培养成功并表现成血管倾向，可能是血管组织工程的潜在资源。     

内皮祖细胞与肿瘤血管新生

血管内皮祖细胞（EPCs）是内皮细胞的前体细胞,特异性表达CD34,CD133和VEGFR-2,具有向血管内皮细胞分化的潜能。EPCs主要位于骨髓和外周血。肿瘤的生长和转移依赖于肿瘤血管新生。肿瘤细胞可合成和释放多种细胞因子,在不同因子的趋化作用下EPCs从骨髓动员至外周血循环,然后迁移和定居到肿瘤组织,经细胞因子诱导分化为成熟内皮细胞,参与肿瘤血管新生。VEGF/VEGFR-2信号途径在EPCs参与的肿瘤血管新生方面起重要作用。     

人胶质瘤干细胞趋化因子受体CXCR4活化促进血管生成的作用

目的从人恶性胶质瘤细胞系U87中分离、培养和鉴定胶质瘤干细胞,观测其CXCR4表达情况及其活化后促血管生成因子分泌的变化。方法通过流式细胞术检测U87细胞中CD133阳性细胞的比例。使用CD133免疫磁珠分离试剂盒通过磁性细胞分选系统分离胶质瘤干细胞。采用间接免疫荧光标记、激光共聚焦扫描显微术观测胶质瘤干细胞中神经巢蛋白（nestin）、胶质纤维酸性蛋白（GFAP）、趋化因子受体CXCR4的表达;以CXCR4配体刺激通过钙流试验检测受体功能,采用酶联免疫吸附试验（EIJSA）检测培养上清中血管内皮生长因子（VEGF）和白细胞介素-8（IL-8）的含量。建立裸鼠皮下移植瘤模型,观察胶质瘤干细胞成瘤情况及瘤体内VEGF表达情况。结果U87细胞系中CD133阳性细胞的比例为0．5％,这些细胞具有干细胞增殖和生长特性;它们表达CXCR4,用其相应配体激活后导致胞内钙流增加、分泌VEGF和IL-8增多。与CD133阴性细胞相比,CD133阳性细胞在体外分泌VEGF、IL-8多,在体内成瘤率高,形成的移植瘤生长迅速,表达更多VEGF。结论人恶性胶质细胞瘤细胞系U87中含有极少量胶质瘤干细胞,表达功能性CXCR4、分泌更多促血管生成因子,提示这些干细胞也直接参与胶质瘤血管生成。     

人外周血与脐血内皮祖细胞生物学特性的比较

背景：内皮祖细胞可从外周血与脐血中获取,是修复各种疾病所致损伤的血管内皮细胞不可或缺的细胞来源。 目的：比较人外周血与脐血来源的内皮祖细胞经体外培养后生物学特性的差异。 方法：通过密度梯度离心法和6%羟乙基淀粉结合密度梯度离心法分别分离人外周血与脐血中的单个核细胞,分别设为脐血源组和外周血源组,计数各组单个核细胞数量,按1.0×106/cm2接种于大鼠尾胶包被的培养皿中,用内皮细胞培养基进行诱导,共培养7 d。 结果与结论：外周血与脐血体外培养分离出内皮祖细胞具有类似的形态学特征。光学显微镜下观察,随着培养天数的增加,大多数细胞由早期的贴壁圆形转变为梭形。外周血源组内皮祖细胞有细胞集落形成,脐血源组可见梭形细胞自行排列生长为典型的线样结构。锥虫蓝染色及绘制细胞生长曲线后发现,外周血源组单个核细胞及内皮祖细胞数量、内皮祖细胞活率及增殖能力均低于脐血源组(P < 0.05)。外周血源组和脐血源组内皮祖细胞在接种后第3天增殖速度达到峰值,在随后的培养中细胞增殖呈衰减态。流式细胞仪及免疫荧光染色检测结果显示,外周血源组和脐血源组内皮祖细胞均可表达具有内皮祖细胞表型的CD133、CD34和血管内皮细胞因子受体2表面标志物,两组既摄取Dil标记乙酰化低密度脂蛋白,也能标记体外内皮祖细胞的标志物荆豆凝集素Ⅰ。结果证实,脐血来源的内皮祖细胞与外周血来源的内皮祖细胞生物学特性相近,脐血来源的内皮祖细胞增殖能力更强。     

人脐带血淋巴管内皮祖细胞的分化及其生物学特征

目的研究脐带血中CD34^＋／CD133^＋／VEGFR-3^＋淋巴管内皮祖细胞经VEGF—C诱导向内皮细胞分化过程中生物学特征的变化,并探讨其分化的机制。方法取脐带血,用PercoU密度梯度离心法分离单形核细胞,再用流式细胞仪分选CD34^＋／CD133^＋／VEGFR-3^＋细胞,然后用VEGF—C诱导分化。在扫描电镜和透射电镜下观察细胞表面形态和细胞内结构的变化,并在激光扫描共焦显微镜下观察特征性标志物的表达变化。结果脐带血中的淋巴管内皮祖细胞表达CD34、CD133和VEGFR-3。CD34^＋／CD133^＋／VEGFR-3^＋细胞经VEGF-C诱导后7d,呈长梭形,细胞伸出板状伪足和丝状伪足,出现较多短的微绒毛。表面可见细胞小凹,细胞质中含有丰富的线粒体和粗面内质网。诱导后14d,细胞已具有内皮细胞的特征,表达淋巴管内皮特异性标志物LYVE-1和5-核苷酸酶,CD133表达消失,细胞质中可见Weibel-Palade小体。结论脐带血中存在CD34^＋／CD133^＋／VEGFR-3^＋淋巴管内皮祖细胞,这些细胞在VEGF—C诱导作用下可能通过VEGF—C／VEGFR-3信号途径分化为淋巴管内皮细胞。     

Hypoxic preconditioning augments efficacy of human endothelial progenitor cells for therapeutic neovascularization

A subset of human peripheral blood mononuclear cells (PB-MNCs) differentiate into endothelial progenitor cells (EPCs) that participate in postnatal neovascularization. Although tissue ischemia can mobilize EPCs from bone marrow, the effects of hypoxia on differentiation and angiogenic function of EPCs are little known. We examined whether hypoxic conditioning would modulate differentiation and function of human PB-MNC-derived EPCs. A subset of PB-MNCs gave rise to EPC-like attaching (AT) cells under either normoxic or hypoxic conditions. However, hypoxia much enhanced the differentiation of AT cells from PB-MNCs compared with normoxia. AT cells released vascular endothelial growth factor (VEGF) protein and expressed CD31 and kinase insert domain receptor/VEGFR-2, endothelial lineage markers, on their surface, which were also enhanced by hypoxia. Both a neutralizing anti-VEGF mAb and a KDR-specific receptor tyrosine kinase inhibitor, SU1498, suppressed PB-MNC differentiation into EPC-like AT cells in a dose-dependent manner. Migration of AT cells in response to VEGF as examined by a modified Boyden chamber apparatus was also enhanced by hypoxia. Finally, in vivo neovascularization efficacy was significantly enhanced by in vitro hypoxic conditioning of AT cells when cells were transplanted into the ischemic hindlimb of immunodeficient nude rats. In conclusion, hypoxia directly stimulated differentiation of EPC-like AT cells from human PB-MNC culture. Moreover, hypoxic preconditioning of AT cells before in vivo transplantation is a useful means to enhance therapeutic vasculogenesis.     

人脐带血内皮祖细胞与血管内皮生长因子和碱性成纤维细胞生长因子共培养及其增殖和迁移能力

背景：目前组织工程心脏瓣膜再内皮化种子细胞主要来源于成熟内皮细胞,内皮祖细胞作为内皮细胞的前体细胞越来越受到人们的关注。 目的：分离和扩增人脐带血内皮祖细胞,观测其体外生物学特性。 方法：密度梯度离心法分离新鲜的脐血中单个核细胞,在含血管内皮生长因子和碱性成纤维细胞生长因子的培养液中培养扩增,通过形态学、免疫荧光和流式细胞仪等对贴壁细胞进行鉴定;并与脐静脉内皮细胞进行增殖和迁移能力比较。 结果与结论：随着培养和诱导时间延长,贴壁细胞形态发生明显的改变,从小圆形变成梭形,逐渐分化成典型成熟内皮细胞的鹅卵石样形态,并可形成特征性的克隆;体外诱导7 d后90%以上贴壁细胞呈Dil-ac-LDL和FITC-UEA-I双阳性;贴壁细胞流式细胞仪分析显示：培养7 d的细胞VEGFR-2、CD34和CD133表达分别占(77.4±4.9)%、(52.4±6.6)%和(19.4±2.1)%,培养28 d的细胞VEGFR-2和CD34表达分别占(81.1±7.4)%和(7.6±3.1)%,而未检测到CD133表达;人内皮祖细胞增殖和迁移能力明显高于人脐静脉内皮细胞(P < 0.05),并且细胞数量可扩增达10⁹ L^-1。结果显示用密度梯度离心法和贴壁筛选法,可从人脐带血分离、纯化内皮祖细胞;内皮祖细胞可诱导分化为内皮细胞,增殖和迁移能力都很强。     

Measuring angiogenic cytokines, circulating endothelial cells, and endothelial progenitor cells in peripheral blood and cord blood: VEGF and CXCL12 correlate with the number of circulating endothelial progenitor cells in peripheral blood

Circulating endothelial cells (CECs) and endothelial progenitor cells (EPCs) are thought to play an important role in the vascularization of damaged tissues and cancers. These cells are also required for tissue-engineered blood vessels and to help skin substitutes revascularize more efficiently. A standard approach to the phenotyping and enumeration of CEC and EPC is key to the development of new therapies, and the identification of biomarkers within the blood that regulate their levels may be important for the treatment of cancer. We have devised an improved multiparameter flow cytometric assay for CEC and circulating EPC enumeration. This assay uses antibodies recognizing CD133 and CD34 to identify EPC and CEC, respectively, and incorporates specific markers CD144 and vascular endothelial growth factor receptor 2 (VEGFR-2) for both CEC and EPC cells. In peripheral blood (PB), mean CEC numbers were 55 +/- 95 mL(-1) and mean EPC numbers were 44 +/- 58 mL(-1) (n = 60). We also found a significant correlation of both plasma VEGF (r = 0.90, p < 0.001) and CXCL12 (r = 0.84, p < 0.001) with EPCs, but not CECs. The cytokines also correlated with each other (r = 0.85, p < 0.001). In umbilical cord blood (UCB) we found on average 13 times more CEC (719 +/- 338 mL(-1)) and 7 times more EPC (299 +/- 245 mL(-1)) than in PB. However, serum VEGF and CXCL12 levels in UCB did not correlate with either EPC or CEC numbers. These results suggest a major role for VEGF and CXCL12 in the control of marrow-derived EPCs in adult PB and provide normal data for comparison with patient populations.     

Bone marrow-derived endothelial progenitor cells are a major determinant of nascent tumor neovascularization

Tumors build vessels by cooption of pre-existing vasculature and de novo recruitment of bone marrow (BM)-derived endothelial progenitor cells (EPCs). However, the contribution and the functional role of EPCs in tumor neoangiogenesis are controversial. Therefore, by using genetically marked BM progenitor cells, we demonstrate the precise spatial and temporal contribution of EPCs to the neovascularization of three transplanted and one spontaneous breast tumor in vivo using high-resolution microscopy and flow cytometry. We show that early tumors recruit BM-derived EPCs that differentiate into mature BM-derived endothelial cells (ECs) and luminally incorporate into a subset of sprouting tumor neovessels. Notably, in later tumors, these BM-derived vessels are diluted with non-BM-derived vessels from the periphery, which accounts for purported differences in previously published reports. Furthermore, we show that specific ablation of BM-derived EPCs with alpha-particle-emitting anti-VE-cadherin antibody markedly impaired tumor growth associated with reduced vascularization. Our results demonstrate that BM-derived EPCs are critical components of the earliest phases of tumor neoangiogenesis.     

The Rho kinase inhibitor fasudil augments the number of functional endothelial progenitor cells in ex vivo cultures

Rho kinase (ROCK) has been implicated in the regulation of vascular tone, endothelial dysfunction, inflammation and remodeling. Endothelial progenitor cells (EPC) have been proven to have the efficacy of therapeutic neovascularization in ischemia. However, the scarcity of EPCs limits cell therapy. Using an in vitro EPC culture assay, Y27632 was found to increase the number of adherent EPCs. In this study, we investigated the effect of fasudil, another ROCK inhibitor being used in the clinic, on EPC number and examined whether EPCs expanded by fasudil are functional in vitro and in vivo. In ex vivo cultures of EPCs, fasudil effectively increased the number of ac-LDL/UEA-1 positive cells as well as adherent cells, in contrast to H89, a less selective ROCK inhibitor. Fasudil also increased EPC numbers in culture up to 10 μM, in a dose-dependent manner. When EPCs expanded with fasudil were examined for the migratory activity toward stromal cell-derived factor-1 and vascular endothelial growth factor, these cells retained functional properties in migration, albeit with some decrease. Fasudil-cultured EPCs labeled with PKH26 showed an activity similar to non-treated EPCs for cellular adhesion into an endothelial cell (EC) monolayer and incorporation into capillary-like structures formed by ECs. Finally, when EPCs cultured with fasudil (106 cells/mouse) were injected into ischemic limbs, these cells showed a blood flow recovery at a level comparable to non-treated control EPCs and increased neovascularization. Therefore, these data suggest that the ROCK inhibitor fasudil can provide a beneficial effect in the treatment of ischemic diseases by increasing EPC numbers.     

CD133(+) human umbilical cord blood stem cells enhance angiogenesis in experimental chronic hepatic fibrosis

The in vivo angiogenic potential of transplanted human umbilical cord blood (UCB) CD133(+) stem cells in experimental chronic hepatic fibrosis induced by murine schistosomiasis was studied. Enriched cord blood-derived CD133(+) cells were cultured in primary medium for 3 weeks. Twenty-two weeks post-Schistosomiasis infection in mice, after reaching the chronic hepatic fibrotic stage, transplantation of stem cells was performed and mice were sacrificed 3 weeks later. Histopathology and electron microscopy showed an increase in newly formed blood vessels and a decrease in the fibrosis known for this stage of the disease. By immunohistochemical analysis the newly formed blood vessels showed positive expression of the human-specific angiogenic markers CD31, CD34 and von Willebrand factor. Few hepatocyte-like polygonal cells showed positive expression of human vascular endothelial growth factor and inducible nitric oxide synthase. The transplanted CD133(+) human stem cells primarily enhanced hepatic angiogenesis and neovascularization and contributed to repair in a paracrine manner by creating a permissive environment that enabled proliferation and survival of damaged cells rather than by direct differentiation to hepatocytes. A dual advantage of CD133(+) cell therapy in hepatic disease is suggested based on its capability of hematopoietic and endothelial differentiation.