人脐静脉内皮细胞用于构建组织工程心脏瓣膜的实验研究

目的：以人脐静脉血管内皮细胞(HUVECs)为种子细胞，体外构建组织工程心脏瓣膜(TEHV)，并对其分泌纤溶物质——组织型纤溶酶原激活物(t-PA)及其抑制物(PAI-1)的作用进行观察。方法：获取并扩增HUVECs，种植在猪脱细胞主动脉瓣叶上，体外静态构建TEHV。观察内皮细胞的形态学变化和生长状况。收集瓣膜培养液，采用发色底物法检测瓣膜内皮细胞分泌的t-PA和PAI-1活性。结果：以猪脱细胞主动脉瓣叶作支架，HUVECs做种子细胞，体外成功构建TEHV，种植的HUVECs在瓣膜表面长成一层连续的细胞层，生长状态良好。瓣膜表面的内皮细胞能够分泌纤溶物质t-PA和PAI-1。结论：HUVECs种植在猪脱细胞瓣膜支架上可以构建TEHV，且瓣膜内皮细胞能够分泌t-PA和PAI-1。     

Fabrication of a novel hybrid scaffold for tissue engineered heart valve

The aim of this study was to fabricate biomatrix/polymer hybrid scaffolds using an electrospinning technique. Then tissue engineered heart valves were engineered by seeding mesenchymal stromal cells （MSCs） onto the scaffolds. The effects of the hybrid scaffolds on the proliferation of seed cells, formation of extracellular matrix and mechanical properties of tissue engineered heart valves were investigated. MSCs were obtained from rats. Porcine aortic heart valves were decellularized, coated with poly（3-hydroxybutyrate-co-4-hydroxybutyrate） using an electrospinning technique, and reseeded and cultured over a time period of 14 days. In control group, the decellularized valve scaffolds were reseeded and cultured over an equivalent time period. Specimens of each group were examined histologically （hematoxylin-eosin [HE] staining, immunohistostaining, and scanning electron microscopy）, biochemically （DNA and 4-hydroxyproline） and mechanically. The results showed that recellularization was comparable to the specimens of hybrid scaffolds and controls. The specimens of hybrid scaffolds and controls revealed comparable amounts of cell mass and 4-hydroxyproline （P〉0.05）. However, the specimens of hybrid scaffolds showed a significant increase in mechanical strength, compared to the controls （P〈0.05）. This study demonstrated the superiority of the hybrid scaffolds to increase the mechanical strength of tissue engineered heart valves. And compared to the decellularized valve scaffolds, the hybrid scaffolds showed similar effects on the proliferation of MSCs and formation of extracellular matrix. It was believed that the hybrid scaffolds could be used for the construction of tissue engineered heart valves.     

环氧氯丙烷对组织工程心脏瓣膜构建中MMP-9表达的影响

目的探讨环氧氯丙烷对组织工程心脏瓣膜构建中基质金属蛋白酶-9(Matrix metalloproteinase-9;MMP-9)表达的影响。方法采用去垢剂和胰蛋白酶消化制备脱细胞猪主动脉瓣膜支架,用3%环氧氯丙烷处理48h的去细胞支架材料作为实验组;用0.2%戊二醛处理48h的去细胞支架材料作为对照组。将培养的人骨髓基质干细胞(human bone marrow mesenchy-mal stem cells;hBMSCs)种植于脱细胞支架上构建组织工程心脏瓣膜(tissue engineered heart valves;TEHV),分别行石蜡包埋切片HE染色和扫描电镜观察TEHV的组织结构,免疫组化检测MMP-9表达的阳性率。结果hBMSCs在实验组脱细胞瓣膜表面生长良好,MMP-9的表达比对照组降低。结论环氧氯丙烷处理的脱细胞猪主动脉瓣膜支架,可以抑制hBMSCs的MMP-9表达,对防止组织工程心脏瓣膜钙化的形成有一定作用。     

Human umbilical cord-derived endothelial progenitor cells promote growth cytokines-mediated neorevascularization in rat myocardial infarction

Background Cell-based vascular therapies of endothelial progenitor cells （EPCs） mediated neovascularization is still a novel but promising approach for the treatment of ischemic disease. The present study was designed to investigate the therapeutic potentials of human umbilical cord blood-derived EPCs （hUCB-EPCs） in rat with acute myocardial infarction. Methods Human umbilical cord blood （hUCB） mononuclear cells were isolated using density gradient centrifugation from the fresh human umbilical cord in healthy delivery woman, and cultured in M199 medium for 7 days. The EPCs were identified by double-positive staining with 1,1＇-dioctadecyl-3,3,3＇,3＇-tetramethylindocarbocyanine percholorate-labeled acetylated low-density lipoprotein （DiI-Ac-LDL） and fluorescein isothiocyanate-conjugated Ulex europaeus lectin （FITC-UEA-I）. The rat acute myocardial infarction model was established by the ligation of the left anterior descending artery. The hUCB-EPCs were intramyocardially injected into the peri-infarct area. Four weeks later, left ventricular function was assessed by a pressure-volume catheter. The average capillary density （CAD） was evaluated by anti-VIII immunohistochemistry staining to reflect the development of neovascularization at the peri-infarct area. The graft cells were identified by double immunofluorescence staining with human nuclear antigen （HNA） and CD31 antibody, representing human origin of EPCs and vascular endothelium, respectively. Expressions of cytokines, proliferating cell nuclear angigen （PCNA）, platelet endothelial cell adhesion molecule （PECAM） and vascular endothelial growth factor （VEGF） were detected to investigate the underlying mechanisms of cell differentiation and revascularization. Results The donor EPCs were detectable and integrated into the host myocardium as confirmed by double-positive immunofluorescence staining with HNA and CD31. And the anti-VIII staining demonstrated a higher degree of microvessel formation in EPCs transplanted rats, associated with a significant improvement of global heart function in terms of the increase of left ventricular end-systolic pressure （LVESP）, ＋dp/dtmax and -dp/dtmax as well as the decrease of LVEDP in rats with EPCs therapy comparing to the control rats （P〈0.05）. Moreover, the expression of the rat PCNA mRNA and PECAM were both enhanced in the EPCs group compared with that of the control group. Conclusions The human umbilical cord blood-derived EPCs could incorporate into new-born capillaries in rat myocardium, induce revascularization and improve the proliferation activity in the peri-infarct area, resulting in the improvement of global heart function. This may indicate a promising stem cell resource in cell-based therapy for ischaemic diseases.     

人脐血内皮祖细胞的体外培养

目的从人脐带血中分离内皮祖细胞（endothelial progenitor cells,EPCs）,建立人脐血内皮祖细胞体外培养的方法,为实现内皮祖细胞的移植及实验研究提供足量的细胞来源。方法采用密度梯度离心法分离人脐带血内皮祖细胞,在EGM-2培养基中培养,采用流式细胞仪、免疫组化和免疫荧光鉴定EPCs。结果脐带血单个核细胞在经EGM-2培养过程中出现梭形贴壁和铺路石样等形态;1周后既分化成EPCs,细胞免疫荧光CD133染色率在培养第7天为（67.2±2.12）%,免疫组化CD34染色率为（89.67±2.05）%,流式细胞仪鉴定该种细胞CD133与KDR的双阳性率达87.8%。可确定该细胞为EPSc。结论采用本培养方法可获得良好的内皮祖细胞用于实验研究。     

骨膜去细胞生物支架在骨缺损小鼠体内的血管化机制

目的：观察骨膜去细胞生物支架对小鼠股骨骨缺损的修复作用及支架内血管形成过程,探讨其血管形成的可能机制。方法：采用物理冻融、化学和生物酶试剂等序贯处理获得骨膜去细胞生物支架。体外实验方面,通过细胞划痕试验观察骨膜去细胞支架浸提液对人脐静脉内皮细胞（HUVEC）迁移的影响以评价骨膜去细胞支架中是否存在促血管化的生物因子,同时通过酶联免疫吸附试验（ELISA）检测支架中的血管内皮生长因子（VEGF）。在体动物实验方面,通过建立小鼠股骨骨缺损模型评价骨膜去细胞生物支架通过促血管化诱导骨修复的可能性。在小鼠股骨远端制备0.5 mm直径的单皮质骨缺损后,于骨缺损处植入骨膜去细胞支架后逐层缝合切口,对照组小鼠骨缺损处不放置材料。分别在术后第7天、第14天、第21天和第28天,取材、固定、脱钙、包埋和切片,通过HE染色评价骨缺损区骨修复情况,通过免疫荧光染色观察血管性血友病因子（vWF）以评价缺损区血管化情况。结果：体外细胞实验表明,去细胞骨膜支架浸提液对HUVEC的增殖没有明显的抑制作用;细胞划痕实验结果显示,与对照组相比,支架浸提液组细胞的迁移面积更大,去细胞骨膜支架浸提液能够有效促进HUVEC的迁移并且在支架浸提液中检测到VEGF,其浓度为210 pg/mL。动物实验方面,HE染色证明去细胞骨膜支架可以促进骨缺损区域血管的生长和新骨形成,免疫荧光染色进一步证明去细胞骨膜支架对骨缺损的修复活动伴随血管化的发生过程,且去细胞骨膜支架中血管的密度随时间延长呈现先增多后减小的趋势。结论：去细胞骨膜支架可以血管化,并且促进骨缺损的愈合。VEGF可能是其血管形成过程中的关键因素。     

Immobilization of decellularized valve scaffolds with Arg-Gly-Asp-containing peptide to promote myofibroblast adhesion

The cell adhesive properties of decellularized valve scaffolds were promoted by immobilization of valve scaffold with arginine-glycine-aspartic acid （RGD）-containing peptides. Porcine aortic valves were decellularized with trypsin/EDTA, and detergent Triton X-100. With the help of a coupling reagent Sulfo-LC-SPDP, the valve scaffolds were immobilized with glycine-arginine-glycine-aspartic acid-serine-proline-cysteine （GRGDSPC） peptide. X-ray photoelectron spectroscopy （XPS） was used for surface structure analysis. Myofibroblasts harvested from rats were seeded onto the valve scaffolds. Cell count by using microscopy and modified MTT assay were performed to assess cell adhesion. Based on the spectra of XPS, the conjugation of GRGDSPC peptide with decellularized valve scaffolds was confirmed. Both cell count and MTT assay showed that myofibroblasts were much easier to adhere to the modified valve scaffolds, which was also confirmed histologically. Our findings suggest that it is feasible to immobilize RGD-containing peptides onto decellularized valve scaffolds. And the technique can effectively promote cell adhesion, which is beneficial for in vitro tissue engineering of heart valves.     

Transplantation of human umbilical cord-derived endothelial progenitor cells promotes re-endothelialization of the injured carotid artery after balloon injury in New Zealand white rabbits

Background Cell transplantation has great potential for promoting endothelial repair and reducing the complications of percutaneous coronary intervention (PCI).The aim of this study was to investigate ...     

内皮祖细胞在胶质瘤新生血管中的募集和整合作用

目的 探讨内皮祖细胞(EPCs)在胶质瘤血管新生化过程中的作用.方法 采用密度梯度离心法分离人脐血EPCs.应用人脑胶质瘤细胞系U87细胞建立原位移植动物模型,于瘤细胞接种后第7天将EPCs经尾静脉注入荷瘤鼠,并分别于尾静脉注射后7、14、21d观察EPCs植入后在移植瘤血管新生过程中的募集、整合作用以及对肿瘤生长的影响.结果 胶质瘤原位移植模型成瘤率为100%.在EPCs植入后14、21d被募集和整合到肿瘤血管中的EPCs数量显著多于第7天(P＜0.05),肿瘤微血管密度和移植瘤体积也显著高于对照组(P＜0.05).结论 人脐血EPCs能够被募集并整合到肿瘤血管中促进胶质瘤生长,提示其在胶质瘤血管新生化过程中可能具有重要作用.     

去细胞组织工程心脏瓣膜构建的实验研究

目的:探讨人脐静脉内皮细胞(HUVECs)种植在去细胞瓣叶上构建组织工程心脏瓣膜的可行性。方法:测定瓣叶去细胞前、后的生物力学性能;观察去细胞瓣叶上内皮细胞生长情况。结果:瓣叶去细胞可获得完整无细胞的纤维支架,瓣叶去细胞前、后的生物力学性能无差异;内皮细胞在去细胞瓣叶表面生长,形成一层基本连续的细胞层。结论:去细胞瓣叶组织是一种良好的纤维支架,可以用于构建组织工程瓣膜;内皮细胞种植在去细胞瓣叶上构建组织工程心脏瓣膜是可行的。     

人脐带血内皮祖细胞的分离、培养与鉴定

目的:分离、培养、鉴定人脐带血内皮祖细胞（EPCs）,为获取大量血管内皮祖细胞提供方法。方法:脐带血采集后,采用6%羟乙基淀粉沉降法和密度梯度离心法获取脐带血单核细胞,再将单核细胞接种于铺设有纤维连接蛋白的培养瓶中,经过体外诱导、培养、分化,完成传代扩增;通过免疫组织化学、免疫荧光染色、流式细胞术对细胞进行鉴定。结果:细胞培养第5天呈现集落样生长,单个细胞呈圆形或梭形,2周后细胞长满瓶底,呈鹅卵石样外观。免疫组织化学检测显示,CD31兔抗人单克隆抗体阳性率91.5%,Anti-Von Willebrand factor antibody（vWF）相关抗原兔抗人单克隆抗体的阳性表达率为72.4%;细胞免疫荧光染色检测显示,吞噬Dil标记的乙酰低密度脂蛋白（+）,发出红色荧光;结合FITC标记的荆豆凝集素Ⅰ（+）,发出绿色荧光;双染（+）,呈黄色荧光。流式细胞术检测CD34阳性率93%,血管内皮细胞生长因子受体2阳性率88.5%,CD133阳性率84.8%。结论:从脐带血中可获取大量CD34+、VEGFR-2+及CD133+血管内皮祖细胞。     

脐血血管内皮祖细胞移植对心肌梗死血管形成的影响

目的 探讨犬脐血血管内皮祖细胞(EPCs) 移植对心肌梗死血管形成的影响.方法 取妊娠犬脐血,体外分离、培养、扩增EPCs,免疫组化鉴定.建立成年杂种犬梗死模型,经BrdU标记的EPCs灌注移植入梗死区域,1、4、8周后处死动物,取心肌标本HE染色确认梗死模型、免疫组化染色BrdU观察EPCs参与梗死心肌血管形成、vW因子染色观察梗死心肌血管并计数以观察EPCs移植组与对照组血管形成差异.结果 免疫组化检测结果表明培养的细胞为EPCs;HE染色示心肌梗死区有大量瘢痕组织、成纤维细胞及小血管形成;免疫组化检测显示梗死心肌区域标本内小血管上存在BrdU阳性细胞;EPCs移植组与对照组心肌梗死后第1、4、8周的心肌缺血区和梗死区的血管计数均无显著差异.结论 犬脐血EPCs梗死心肌移植可参与血管形成,但不能促进心肌的血管再生.     

金黄色葡萄球菌超抗原样蛋白-5抑制人脐血源性内皮祖细胞黏附功能及其机制研究

目的 研究金黄色葡萄球菌超抗原样蛋白-5 (staphylococcal superantigen-like protein-5,SSL5)与人脐血源性内皮祖细胞(endothelial progenitor cells,EPCs)表面P-选择素糖蛋白配体-1 (P-selectin glycoprotein liga...     

胎儿生长受限孕妇外周血及新生儿脐血中内皮祖细胞数量与功能的变化

目的:观察胎儿生长受限(FGR)孕妇外周血及新生儿脐血中内皮祖细胞(EPCs)数量与功能的变化.方法:选择FGR孕妇及新生儿15例和对照组健康孕妇及新生儿15例,密度梯度离心法收集外周血及脐血中单个核细胞(MNCs),接种在人纤维连接蛋白包被的培养板,诱导分化培养9 d后收集贴壁细胞进行细胞化学分析.激光共聚焦显微镜下...     

内皮祖细胞的生物学特性研究进展

内皮祖细胞在体内外能分化为成熟内皮细胞。目前,内皮祖细胞已被证实存在于成年人外周血,骨髓和人脐带血中。本综述总结了近年来内皮祖细胞的生物学研究进展,并讨论了其在心血管疾病中的潜在的治疗作用。     

百里醌对内皮祖细胞的抑制作用

目的探讨百里醌对人脐血来源的内皮祖细胞血管生成的抑制作用及其可能机制。方法采用贴壁选择法培养人脐血内皮祖细胞(EPCs),DiI-ac-LDL吞噬试验及VEGFR-2、Ⅷ因子和CD34细胞免疫组化证实细胞属性;百里醌作用EPCs后,CCK-8法检测细胞增殖;Transwell小室实验测定EPCs体外侵袭能力;小管形成实验检测EPCs体外小管形成能力;Western blotting检测EPCs中MMP-2和MMP-9蛋白表达。结果体外成功培养出人脐血内皮祖细胞,百里醌可显著抑制体外EPCs增殖,IC50=51.2nmol/L;百里醌可抑制体外EPCs侵袭和小管形成,呈浓度依赖性;百里醌可显著下调EPCs中MMP-2和MMP-9的表达。结论百里醌可能通过抑制EPCs中MMP-2和MMP-9的表达从而抑制EPCs参与的血管生长,从而有望作为有效的血管生成抑制药物。     

Gd-BOPTA标记对人脐血内皮祖细胞生物学特性的影响与MR成像研究

目的探讨Gd-BOPTA标记人脐血内皮祖细胞(endothelial progenitor cells,EPCs)的方法和对标记EPCs生物活性的影响,观察标记EPCs的体外磁共振成像特点。方法应用密度梯度离心法结合贴壁筛选法分离培养EPCs。采用jetPEITM-FluoF介导Gd-BOPTA标记EPCs,比较不同标记浓度和标记时间对EPCs生物活性的影响,收集未标记细胞和标记24 h的细胞进行体外MR成像,比较不同浓度标记的细胞在不同扫描序列中的信号强度变化。结果荧光显微镜下观察,标记的EPCs胞质内可见绿色荧光颗粒,透射电镜可见胞质内散在分布许多Gd颗粒,颗粒主要位于胞质的细胞器如高尔基体周围以及附着在细胞膜内层上。Gd-BOPTA标记规律呈"抛物线"样,即随着标记浓度增高和标记时间的延长,细胞内聚集的Gd颗粒增多,细胞的标记率也增高,但在浓度为25μg/ml标记24 h标记率达峰值[(88.2±1.6)%]后,标记率逐渐降低。在标记浓度低于25μg/ml标记24 h时,对细胞的黏附能力、迁移能力及增殖能力均无影响(P>0.05)。在T1 WI序列最大相对信号强度出现在浓度为25μg/ml时,而后信号降低,与对照管相比差异显著(P<0.05),在T2 WI和T2*WI序列上相对信号强度变化无显著性差异(P>0.05)。结论 jetPEITM-FluoF可介导Gd-BOPTA有效地标记EPCs,对MR信号的影响主要为T1WI正性效应,最适标记浓度和最佳标记时间分别为25μg/ml、24 h。     

环氧氯丙烷在组织工程心脏瓣膜构建中对基质金属蛋白酶-1表达的影响

目的探讨环氧氯丙烷对组织工程心脏瓣膜构建中基质金属蛋白酶－1（matrix metalloproteinase-1 MMP-1）表达的影响。方法采用去垢剂和胰蛋白酶消化制备的脱细胞猪主动脉瓣膜支架作为对照组,用加用3％环氧氯丙烷处理24小时的去细胞支架材料作为实验组。将培养的人骨髓基质干细胞（human bone maiTow derived stroma cells BMSCs）种植于脱细胞支架上构建组织工程心脏瓣膜（tissue engineering heart valve 1EHV）,分别行石蜡包埋切片、HE染色和扫描电镜观察TEHV的组织结构,并行逆转录-聚合酶链反应（RT—PCR）测定BMSCs分泌MMP-1的功能。结果BMSCs在实验组脱细胞瓣膜表面生长良好,MMP-1的表达比对照组降低。结论环氧氯丙烷处理的脱细胞猪主动脉瓣膜支架,可以抑制BMSCs的MMP-1表达。     

体外构建组织工程心脏瓣膜动物实验初步研究

目的探讨应用去细胞猪主动脉支架(decellularized porcine aortic valve scaffold，APAVS)与兔骨髓干细胞(rabbit bone marrow stromal cells，RBMSCs)体外构建组织工程心脏瓣膜的可行性。方法采用去垢剂-核酸酶消化法处理，去除猪主动脉瓣细胞成分，并做去细胞前后的形态学检查和生物力学测定；在去细胞支架上种植兔骨髓干细胞，行形态学检查和免疫组化测定。结果光镜及电镜证实，猪主动脉瓣膜中的细胞成分可完全去除，获得完整无细胞的纤维网状支架；瓣叶去细胞前后的断裂强度和断裂伸长率无明显变化；种植的RBMSCs可在ACPAV表面形成一层连续的细胞层。结论种植RBMSCs于ACPAV上，可体外构造组织工程人工心脏瓣膜。