基因修饰的生物可降解人工骨修复骨缺损的血管化研究

目的评价转染骨形成蛋白2（bone morphogenetic protein 2，BMP-2）基因的骨髓间充质干细胞（marrow mesenchymal stem cells，MSCs）复合生物可降解人工骨修复兔桡骨缺损的血管化过程，观察BMP-2基因对促进移植骨血管化的影响。方法利用携带BMP-2基因的腺病毒载体（adenovirus carrying BMP-2 gene，Ad—BMP-2）转染MSCs及复合人工骨制备。取新西兰大耳白兔60只制成双侧桡骨中段1．5cm骨缺损模型，随机分为4组，每组15只（30侧）。各组采用不同材料植入缺损，A组：Ad—BMP-2转染MSCs＋聚乳酸／聚己内酯（polylactic acid／polycaprolactone，PLA／PCL）；B组：β-半乳糖酐酶基因的重组腺病毒转染MSCs＋PLA／PCL；C组：未转染MSCs＋PI，A／PCL；D组：单纯PLA／PCL。分别于术后4、8和12周各组处死5只动物，行X线片、微血管分布、组织学、透射电镜观察，并行血管内皮生长因子（vascular endothelial growth factor，VEGF）表达检测及微血管计数。结果A组4周时见移植骨内片状成骨影，有较多新生血管长入，支架孔隙内充满软骨痂，功能活跃的成骨细胞围绕微血管生长，VEGF表达及微血管数均明显高于其它各组，且差异有统计学意义（P〈0．01）；8周时移植骨内成骨逐渐增多，微血管迂曲扩张并相互连接，软骨痂转变为小梁骨；12周时皮质骨连续，髓腔再通，微血管呈规则地纵向排列。B、C组成骨能力较弱，血管再生缓慢，12周时骨缺损得到初步修复，微血管沿新生骨小梁孔隙分布。D组各时间点新生血管少见，12周时骨端硬化，缺损区被纤维组织填充。结论BMP-2基因转染可通过上调VEGF表达，间接诱导移植骨血管化，促进种子细胞成活，加速新骨形成。     

血管内皮生长因子基因转染骨髓间充质干细胞移植于梗塞心肌的实验研究

目的 探讨骨髓间充质干细胞（MSCs）移植联合血管内皮生长因子（VEGF）基因转染对大鼠梗塞心肌组织的修复重建、血管再生及梗塞后心功能的影响。方法 体外分离、培养、纯化SD大鼠的MSCs，以BrdU标记MSCs，腺病毒介导VEGF基因转染MSCs。建立大鼠急性心肌梗死模型4周后，随机分为4组（每组10只），分别行梗塞心肌内注射：转染VEGF基因的MSCs移植组（组Ⅰ）、单纯MSCs移植组（组Ⅱ）、单纯VEGF基因治疗组（组Ⅲ）和以注射无血清IMDM培养液为对照组（组Ⅳ）。移植4周后观察移植细胞的分化和新生血管的形成，并通过超声多普勒检测心功能变化。结果 组Ⅰ和组Ⅱ中，梗塞心肌处可见BrdU标记的移植细胞，cTnT染色阳性。超声心动图检查发现，组Ⅰ和组Ⅱ的左室射血分数（LVEF）的改善显著高于对照组（P均〈0．01），而组Ⅰ的LVEF改善程度要明显高于组Ⅱ；部分BrdU染色阳性的细胞可以分化成为内皮细胞，参与构成了梗塞区域的新生毛细血管。相对于对照组，组Ⅰ和组Ⅲ都有明显的血管新生（P均〈0．01）。结论 MSCs移植联合VEGF基因转染可以通过促进心肌再生和新生血管的形成来重建缺血心肌，显著改善心功能。     

血管内皮生长因子基因转染血管内皮祖细胞治疗肢体缺血的实验研究

目的利用血管内皮生长因子（vascular endothelial growth factor,VEGF-165）基因转染体外诱导的血管内皮祖细胞（endothelial progenitor cells,EPCs）,并移植到下肢缺血的新西兰兔体内,观测其促进血管新生,改善肢体缺血的效果。方法（1）梯度离心法分离兔骨髓单个核细胞,然后用含有VEGF、bFGF、IGF-1的M199培养液诱导培养EPCs。并以免疫荧光、透射电镜等方法进行鉴定。（2）用携带VEGF165基因的腺病毒质粒（Adv-GFP-VEGF165）转染所培养的细胞,ELISA法检测上清液中VEGF蛋白的表达。（3）制作兔下肢缺血模型,并将其随机分为A、B、C 3组,分别移植EPCs、VEGF165基因转染后的EPCs、M199培养基,多种方法检测移植效果及局部整合情况。结果（1）自兔骨髓诱导出梭形贴壁细胞,免疫荧光及电镜检测证实为EPCs。（2）Adv-GFP-VEGF165成功转染EPCs,ELISA法检测转染VEGF165后的EPCs其上清液中VEGF蛋白浓度明显升高。（3）Brdu示踪显示移植细胞整合到缺血局部,CTA及免疫组化检查显示VEGF-165基因转染后的EPCs移植后其改善肢体缺血效果优于其他两组。结论VEGF基因转染EPCs后能改进EPCs质量,移植后促血管新生能力增强,其效果优于未转染组。     

骨髓间质干细胞移植梗死心肌后细胞因子分泌及对血管新生的影响

目的研究骨髓间质干细胞(MSCs)移植梗死心肌后细胞因子的分泌及其对血管新生的作用.方法贵州香猪24只,按照计算器随机数法随机分为对照组、实验组.抽取骨髓液3 ml,按照Wakitani的方法培养出骨髓间质干细胞,经5-氮胞苷(5-aza)诱导后,5-溴脱氧尿苷(BrdU)标记备用.开胸结扎左冠状动脉前降支,自体骨髓间质干细胞分别经局部注射和结扎的左冠状动脉前降支远端灌注移植入自体急性心肌梗死区域,对照组以DMEM作对照.术后3周、6周取标本,免疫组织化学法、计算机图象分析检测组织血管内皮生长因子(VEGF)、碱性成纤维细胞生长因子(bFGF)和Ⅷ因子表达.结果实验组梗死区3周、6周bFGF、VEGF灰度值明显高于对照组(P<0.01),微血管计数明显增多(P<0.01).结论自体骨髓间质干细胞移植梗死心肌后能分泌VEGF、bFGF,诱导血管新生.     

血管内皮生长因子165基因转染的骨髓基质细胞异位成骨的初步研究

目的：将血管内皮生长因子165（VEGF165）基因转染的大鼠骨髓基质细胞（MSCs）和β-磷酸三钙复合后,植入原大鼠肌肉中,探索转染外源基因的MSCs异位成骨能力。方法：SD大鼠12只,在全麻及无菌条件下取其左侧股骨的骨髓基质细胞,并用矿化液诱导培养。在脂质体介导下将构建成功的真核表达载体pcDNA3.1-VEGF165转染到诱导培养的MSCs,G-418筛选阳性细胞克隆,将阳性克隆细胞和未转染的MSCs共同接种于β-磷酸三钙上,体外培养7天后,植入原大鼠肌肉内。分别于4周、8周和12周处死动物,观察异位成骨情况。结果：骨髓基质细胞-β-磷酸三钙复合体植入肌肉后,材料周围血管生长较多,随着植入时间的延长,小的骨岛逐渐融合为大的骨块,并有骨髓腔样结构,表现出较好的异位成骨能力。结论：应用VEGF165基因转染MSCs作为种子细胞植入体内后,有利于发挥VEGF165的血管化作用,同时促进组织工程骨的成骨速度,将会成为组织工程骨血管化探索的方向。     

微囊化重组CHO细胞移植促进大鼠心肌梗死后血管新生的实验研究

目的在大鼠心肌梗死部位植入微囊化重组中华仓鼠卵巢（chinese hamster ovary，CHO）细胞，观察其分泌的血管内皮细胞生长因子（VEGF）是否可以促进心肌梗死部位的血管新生，改善心功能。方法通过质粒转染的方法构建可以分泌VEGF的重组CHO细胞系，用微囊包裹，观察微囊内细胞的生长及分泌情况。制备大鼠心肌梗死模型，随机将48只8周龄SD雄性大鼠分成微囊化细胞移植组（MC—CHO组）、单纯细胞移植组（CHO组）、空微囊移植组（MC组）和无血清培养基移植组（对照组），每组12只。移植3周后检测心功能改善情况，病理切片观察微囊结构及囊内细胞存活情况，注射部位微血管计数比较促血管新生效果。结果体外检测可见重组CHO细胞在微囊生长迅速，第8d时培养上清中VEGF达3852pg／ml；移植3周后MC—CHO组左心室大小和心功能明显好于其它3组，差异有统计学意义（P〈0．05）；局部微血管密度MC—CHO组较CHO组、MC组和对照组明显增加（22．3±3．1vs．15．6±2．8，11．4±2．5和13．2±2．7个／每高倍视野，P〈0．05）；组织学检查可见微囊结构完整，内有存活且具有分泌功能的CHO细胞。结论微囊化重组CHO细胞移植可促进大鼠心肌梗死后血管新生，改善心功能。     

hTGF-β1基因转染骨髓间充质干细胞椎间盘移植术后的表达

目的 检测腺病毒介导的hTGF-β1基囚转染骨髓间充质干细胞椎间盘移植后hTGF-β1基因的表达。方法 兔骨髓间充质干细胞体外分离培养扩增，Ad-hTGF-β1转染后采用组织工程方法自体移植于椎间盘中，在术后1周、2周、4周、6周、8周取材，RT-PCR和免疫组化方法检测hT-GF-β1的表达。结果 在Ad-hTGF-β1转染MSCs移植组，RT-PCR可检测到hTGF-β1mRNA的表达，对照组未检测到hTGF-β1mRNA的表达，免疫组织化学染色结果显示，与对照组比较Ad-hT-GF-β1转染MSCs移植各组阳性细胞数量和灰度值均有非常显著性差异（P〈0．01）。结论 腺病毒介导的hTGF-β1基因转染骨髓间充质干细胞椎间盘移植后hTGF-β1基因的可高表达。     

肝细胞生长因子基因转染骨髓间充质干细胞对脂肪颗粒移植存活率的影响

目的研究携带人肝细胞生长因子基因的重组腺病毒（Ad—HGF）修饰骨髓间充质干细胞（MSCs）对大鼠脂肪颗粒移植存活率的影响。方法用携带绿色荧光蛋白的重组腺病毒（Ad-GFP）、Ad—HGF转染雄性Wistar大鼠MSCs,测定转染效率与感染上清中肝细胞生长因子（HGF）的表达。用雌性Wistar大鼠150只,随机分为5组：空白对照组（A组）、Ad—HGF组（B组）、MSCs组（C组）、Ad—GFP感染MSCs组（D组）和Ad—HGF感染MSCs组（E组）,每组30只。各组均匀振动5分钟,将颗粒脂肪移植于自体背部皮下;移植后3、5、7、14、28、60d,每组各取5只大鼠脱颈处死,取出移植物;测体积、HE、Masson染色观察病理改变,免疫组织化学法测定组织中HGF表达和血管生成。结果积分吸光度＝100时,Ad—GFP转染MSCs效率可达89．6％;移植后3、5、7、14d,E组移植物中HGF的表达高于其他各组（P〈0．05）;移植后5、7、14、28、60d,E组血管数量也多于其他各组（P〈0．05）;28d和60d时,E组脂肪颗粒体积保持率明显好于其他4组（P〈0．05）。结论携带HGF基因的MSCs在移植物中能够持续表达HGF,有效地减少脂肪颗粒移植后的吸收,从而提高移植颗粒脂肪的存活率。     

骨髓间充质干细胞移植联合透壁心肌打孔复合缓释支架在急性心肌梗死血运重建中的作用

目的探讨骨髓间充质干细胞（MSCs）移植联合透壁心肌打孔复合缓释支架对急性心肌梗死后血运重建的作用,为临床外科治疗心肌梗死提供依据。方法建立猪急性心肌梗死模型后,将24只猪采用随机数字表法分为4组,每组6只,对照组：单纯建立心肌梗死模型;MSCs组：心肌梗死后移植MSCs;透壁打孔再生血管术（TMDR）加支架组：心肌梗死后打孔加复合碱性生长因子（bFGF）肝素化缓释抗凝支架置入;MSCs联合TMDR加支架组：心肌梗死后打孔加复合bFGF的肝素化缓释抗凝支架置入联合MSCs移植。实验后3个月检测、分析4组的梗死区域心肌梗死面积和血管密度。结果术后3个月,病理组织学检测显示,MSCs组、TMDR加支架组和MSCs联合TMDR加支架组梗死面积均较对照组明显减少（27.9%±3.1%vs.48.9%±2.7%,P=0.000;20.3%±1.7%vs.48.9%±2.7%,P=0.000;12.5%±1.9%vs.48.9%±2.7%,P=0.000）,血管密度均有不同程度的增加（8.4±1.2个/高倍视野vs.4.5±1.4个/高倍视野,P=0.001;11.5±2.6个/高倍视野vs.4.5±1.4个/高倍视野,P=0.001;15.6±1.4个/高倍视野vs.4.5±1.4个/高倍视野,P=0.000）;其中MSCs联合TMDR加支架组梗死面积的减少和血管密度增加的程度较MSCs组和TMDR加支架组更明显（P=0.010,0.020）。结论MSCs移植联合TMDR加复合bFGF的肝素化缓释抗凝支架置入能减少心肌梗死面积,增加心肌梗死区域血管密度,从而提高MSCs移植在急性心肌梗死中的治疗作用,为临床外科治疗心肌梗死提供了新的治疗思路。     

同时携带人血管内皮生长因子和血管生成素基因的内皮祖细胞血管再生研究

目的用腺相关病毒（adeno-associated virus,AAV）载体将人血管内皮生长因子165 （vascular endothelial growth factors,VEGF165）和血管生成素-1（angiopoietin-1,Angl）基因同时转入骨髓源性内皮祖细胞（endothelial progenitor cells,EPCs）中,观察外源基因的表达并评价其促血管再生的能力。方法用同时携带人VEGF165和Angl基因的AAV载体AAV2-hAngl/VEGF165转染体外培养的兔骨髓源EPCs,用RT-PCR和细胞免疫化学法检测外源基因的表达。实验用新西兰大白兔24只,制作成右下肢缺血模型,随机分成3组：PBS、EPC和EPC/AV组。造模后第10天,向缺血肌组织中分别注射PBS、EPCs和AAV2-hAngl/VEGF165转染的EPCs,用免疫组织化学法评价其血管再生效应。结果EPCs可高效地被AAV2-hAngl/VEGF165转染而表达Angl和VEGF165。细胞移植4周后,EPC/AV组存活的EPCs密度（283±137）/mm^-2明显高于EPC组（191±88）/mm^-2;EPC/AV组的毛细血管密度（856±212）/mm^-2明显高于EPC组（564±177/mm^-2）和PBS组（308±112）/mm^-2;α-SMA阳性血管密度（6.9±3.0）/mm^-2明显高于PBS组（3.6±1.8）/mm^-2,P〈0.05。结论AAV载体可同时将人VEGF165和Angl基因转入EPCs中,转染后的EPCs具有更强的促血管再生能力。     

Mesenchymal stem cells participate in angiogenesis and improve heart function in rat model of myocardial ischemia with reperfusion.

OBJECTIVE: The effect of transplanted mesenchymal stem cells (MSCs) on the left ventricular (LV) function and morphology in a rat myocardial infarct heart with reperfusion model were analyzed. METHODS: One week after 60 min of myocardial ischemia and reperfusion by left anterior descending artery (LAD) occlusion, 1.0x10(7) 6-diamidino-2-phenylindole (DAPI)-labeled MSCs were injected into the infarcted myocardium and compared with controls, and sham-operated rats, in which a cell-free serum medium was injected into the infarcted region or the myocardial wall, respectively. Measurement of vascular endothelial growth factor (VEGF) expression 1 week after MSC injection using Western blot analysis (n=5), and immunohistochemical staining using HE staining and fluorescent microscopy of the DAPI-positive regions from MSC implantation, cTnT immunostaining of potential myocardial-like cells, and SM-actin and CD31 immunostaining demonstrating neovascular transformation of implanted MSCs 1 week, 2 weeks and 4 weeks after transplantation (n=5). Hemodynamic measurements were performed after 4 weeks in vivo. Subsequently, hearts were quickly removed and cut for histological analysis using HE staining with measurement of the infarcted LV-area, the LV-wall thickness within the scar segment compared to non-infarcted scar segments, and the capillary density counting capillary vessels with 400x light microscopy (n=10). RESULTS: Measurement of hemodynamics 4 weeks after transplantation in vivo showed LV function to be significantly greater in MSCs than in the control group. Semi-quantitative histomorphometric examinations showed a significantly lower infract size, a greater LV-wall thickness, and a lower Hochman-Choo expansion index in the MSC-treated group compared to the control group. Immunofluorescence demonstrated that transplanted MSCs were positive for cTnT, suggesting that a small number of transplanted MSCs can differentiate into cardiomyocytes. Other MSCs were positive for CD31 and SM-actin. The transplanted MSCs in MI area had significantly higher expression rates of cTnT, CD31 and SM-actin 2 weeks after transplantation. HE staining showed marked augmentation of neovascularization in the MSC group. Semi-quantitative analysis demonstrated that capillary density was significantly higher in the MSC group than in the control group. CONCLUSION: Implanted MSCs could improve cardiac structure and function through the combined effect of myogenesis and angiogenesis.     

磁性靶向材料介导骨髓间充质干细胞经静脉移植修复梗死心肌

目的探讨用磁性靶向材料介导骨髓间充质干细胞（MSCs）经静脉移植时到达心肌梗死部位的程度以及对心肌梗死修复的影响。方法取体外扩增的第4代MSCs，先测定MSCs的表面标记，用含10μmol的5-氮杂胞苷诱导后，将MSCs细胞核DAPI（4，6-联脒-2-苯基吲哚）染色后备用移植。将28只SD大鼠分为3组，A组：10只，磁性靶向材料和MSCs接触结合后经大鼠尾静脉移植，将磁石接触心肌梗死部位皮肤表面30min后继续饲养；B组：9只，未与磁性靶向材料结合的MSCs经大鼠尾静脉移植；C组：9只，将MScs直接移植心肌梗死部位。于移植2d后检查MSCs在梗死部位聚集的情况，30d后检查心肌梗死部位的功能及形态的改变。结果在透射电子显微镜下观察可见3～5个磁性靶向材料分子和MSCs的细胞膜结合。A组MSCs归巢率为38％，B组6％，C组53％，A组和C组聚集MSC数目明显多于B组（P〈0．01）。A组和C组移植后左心室射血分数（LVEF）、左心室短轴缩短率（LVFS）较移植前明显改善（LVEF46％±6％VS．38％±8％，51％±5％ vs．35％±4％；LVFS28％±6％vs．20％±7％，32％±4％vs．20％±5％，P〈0．05）；光学显微镜下观察梗死心肌内均可找到标记DAPI的移植细胞。B组移植后左心室收缩功能各项指标无明显改善，光学显微镜下在梗死心肌内未找到标记了DAPI的移植细胞（MSCs归巢率为38％）。C组与A组结果比较差异无统计学意义，但实验过程中死亡率较高。结论磁性靶向材料介导MSCs经静脉移植方法能聚集更多的MSCs于梗死心肌部位，减小梗死区面积，有效改善心肌梗死后的心功能。     

Optimal temporal delivery of bone marrow mesenchymal stem cells in rats with myocardial infarction.

OBJECTIVE: This study was designed to determine the optimal time point for bone marrow mesenchymal stem cell (MSC) transplantation after myocardial infarction (MI). METHODS: MSCs from donor rats were labeled with DAPI before transplantation. The animals underwent MI by ligation of left anterior descending coronary artery, and received intramyocardial injection of MSCs at 1h, 1 week and 2 weeks after MI, respectively. Sham-operated and MI control groups received equal volume phosphate buffered saline. Cardiac function, histological analysis and immunoblot for troponin T were performed 4 weeks after cell transplantation. RESULTS: MSC transplantation attenuated left ventricular chamber dilation, reduced infarct size, and improved cardiac function in rats after MI. The greatest benefit was achieved in rats that received cells 1 week after MI, engrafted MSC survival, angiogenesis and functional cardiomyocytes in the injured hearts were more abundant in these rats than that in other transplantation groups. CONCLUSIONS: The optimal functional benefit of MSC transplantation was observed in 1-week transplantation group. At this time point scar formation has not occurred and the inflammation is reduced, which should facilitate integration of transplanted cells and functional recovery.     

Angiogenic pretreatment improves the efficacy of cellular cardiomyoplasty performed with fetal cardiomyocyte implantation

BACKGROUND: Cell implantation into areas of myocardial infarction (cellular cardiomyoplasty) may be limited in efficacy because of the lack of blood supply to these areas of myocardium, resulting in early loss of transplanted cells. We therefore tested the hypothesis that pretreatment of infarcted myocardium with angiogenic therapy, followed by cell transplant, would be more effective than the application of either strategy alone. METHODS: Fischer 344 rats underwent left coronary artery ligation and injection of an adenovirus encoding VEGF 121, an empty expression cassette control vector, or saline solution. Capillary density in the infarcted region was determined in preliminary studies. Cardiomyocytes harvested from syngeneic Fischer rat fetuses were prelabeled and then injected directly into the infarct area 3 weeks after vector administration. Exercise treadmill testing was performed 2 weeks after cell transplantation, after which a cell viability index was calculated as the number of implanted (prelabeled) nuclei divided by the number of coadministered microspheres detected in sections of implanted myocardium. RESULTS: Capillary density in the area of infarction was significantly greater in adenovirus encoding VEGF 121 compared with rats injected with saline solution (P =.001). The cell survival index was also greater in adenovirus encoding VEGF 121 compared with animals injected with empty expression cassette control or saline solution (P =.0045). Exercise tolerance was nearly doubled in animals receiving adenovirus encoding VEGF 121 3 weeks prior to cell implantation compared with animals receiving adenovirus encoding VEGF 121 or cells alone or those receiving adenovirus encoding VEGF 121 at the time of cell implantation (P <.001). CONCLUSIONS: Pretreatment of an infarcted region of the heart with angiogenic mediators such as VEGF can enhance the efficacy of cellular cardiomyoplasty, presumably by creating a more favorable environment for the survival of transplanted cells.     

Significant improvement of heart function by cotransplantation of human mesenchymal stem cells and fetal cardiomyocytes in postinfarcted pigs

BACKGROUND: Viable cardiomyocytes after myocardial infarction (MI) are unable to repair the necrotic myocardium due to their limited capability of regeneration. The present study investigated whether intramyocardial transplantation of human mesenchymal stem cells (hMSCs) or cotransplantation of hMSCs plus human fetal cardiomyocytes (hFCs; 1:1) reconstituted impaired myocardium and improved cardiac function in MI pigs. METHODS AND RESULTS: Cultured hMSCs were transfected with green fluorescent protein (GFP). Six weeks after MI induction and cell transplantation, cardiac function was significantly improved in MI pigs transplanted with hMSCs alone. However, the improvement was even markedly greater in MI pigs cotransplanted with hMSCs plus hFCs. Histological examination demonstrated that transplantation of hMSCs alone or hMSCs plus hFCs formed GFP-positive engrafts in infarcted myocardium. In addition, immunostaining for cardiac alpha-myosin heavy chain and troponin I showed positive stains in infarcted regions transplanted with hMSCs alone or hMSCs plus hFCs. CONCLUSIONS: Our data demonstrate that transplantation of hMSCs alone improved cardiac function in MI pigs with a markedly greater improvement from cotransplantation of hMSCs plus hFCs. This improvement might result from myocardial regeneration and angiogenesis in injured hearts by engrafted cells.     

Long-term improvement of cardiac function in rats after infarction by transplantation of embryonic stem cells

OBJECTIVE: This study was designed to investigate the feasibility of and potential functional improvement with embryonic stem cell transplantation in rats 32 weeks after myocardial infarction. METHODS: Before cell transplantation, cultured embryonic stem cells were transfected with the complementary DNA of green fluorescent protein to identify engrafted cells in myocardium. Myocardial infarction was induced by ligation of the left coronary artery. Either 3 x 10(5) mouse embryonic stem cells or an equivalent volume of cell-free medium was injected into injured myocardium within 20 minutes after induction of myocardial infarction. RESULTS: Embryonic stem cell transplantation significantly increased the survival rate in rats undergoing myocardial infarction during the experimental period of 32 weeks. Hemodynamic and echocardiographic data showed that embryonic stem cell transplantation significantly improved ventricular function relative to the myocardial infarction plus medium control group. Tissue positive for green fluorescent protein was found in the injured myocardium with cell transplantation. The proportion of myocardium positively immunostained by antibodies against alpha-myosin heavy chain and cardiac troponin I was greater in the infarcted area with embryonic stem cell transplantation than in the injured myocardium with medium injection. Single green fluorescent protein-positive cells with a rod shape and clear striations were observed in cardiomyocytes isolated from infarcted hearts with embryonic stem cell transplantation. In addition, the number of blood vessels in injured myocardium was greater in the cell-transplanted myocardial infarction group than in the medium-injected myocardial infarction group. CONCLUSIONS: Engrafted embryonic stem cells differentiated into cardiomyocytes in injured myocardium, caused an angiogenetic effect, and subsequently improved cardiac function during the 32-week observation period.     

人VEGF165基因在狗骨髓基质细胞中的表达

目的 :检测转染 pcDNA3 hVEGF165狗骨髓基质细胞的VEGF165mRNA表达。方法 :用脂质体介导转染狗骨髓基质细胞 ,用免疫组化及RT PCR检测VEGFmRNA的表达。结果 :重组质粒 pcDNA3 hVEGF165转染骨髓基质细胞后 ,免疫组化及RT PCR检测有VEGFmRNA的表达。结论 :采用脂质体介导的方法可将hVEGF165基因转染至狗骨髓基质细胞并表达外源性基因     

Allopurinol/uricase and ibuprofen enhance engraftment of cardiomyocyte-enriched human embryonic stem cells and improve cardiac function following myocardial injury.

OBJECTIVE: A major limitation of stem cell transfer is early donor-cell death. Here, we seek to enhance myocardial repair following injury through transplantation of cardiomyocyte-enriched human embryonic stem cells (hESC) and recipient treatment with cytoprotective (allopurinol+uricase) and anti-inflammatory (ibuprofen) agents. METHODS: We injected 10(6) (15% hESC-derived cardiomyocytes) green fluorescent protein (GFP+) hESC in the infarcted area following left anterior descending artery (LAD)-ligation in SCID-beige mice. In Group I, 1.6 mg allopurinol and 0.2 mg of uricase were injected i.p. for 3 days prior to cell transplantation. In Group II, 0.35 mg/ml of ibuprofen were added to the drinking water before and after cell implantation. In Group III, the LAD was ligated and allopurinol/uricase was administered without cell treatment. In Group IV, ibuprofen was added to the drinking water and the LAD was ligated without additional cell treatment. In Group V, only cells were transplanted. Group VI involved infarcted controls and Group VII involved sham-operated mice (all groups: n=5). We evaluated heart function (ejection fraction (EF)) by MRI (4.7 T) 3 weeks later. The hearts were harvested for histology. RESULTS: Differentiated hESC formed clusters and expressed alpha-sarcomeric actin and Connexin 43. Cell treatment improved heart function, which was best in the ibuprofen- and allopurinol-treated groups (+cell transfer), compared to the infarcted controls [EF: Group I: 76.6+/-8.6%, Group II: 78.6+/-7.3%, Group III: 58.1+/-5.7%, Group IV: 53.9+/-5.2%, Group V: 57.7+/-7.5%, Group VI: 43.5+/-4.3%, and Group VII: 66.3+/-7.8%]. We did not observe tumors in any group. CONCLUSIONS: Allopurinol/uricase and ibuprofen enhance differentiated hESC-engraftment and myocardial restoration following transplantation into the injured heart.     

Purified human bone marrow multipotent mesenchymal stem cells regenerate infarcted myocardium in experimental rats

Recent findings suggest the feasibility of cardiac repair by transplantation of bone marrow mesenchymal stem cell (MSCs). However, it remains controversial regarding which cell type is the best source for transplanting into the ischemic heart because of lack of well-defined cell markers. In this study, we investigated the in vitro and in vivo effects of the novel multipotent marrow mesenchymal stem cells (MMSCs) from human bone marrow. Pluripotent markers (Oct4, Bmi1, and Abcg2) and vascular endothelial growth factor (VEGF) were detected by RT-PCR and immunofluorescence in MMSCs. Myocardial differentiation was induced in the expanded MMSC cultures by treatment with 5-azacyline. Expressions of VEGF in the animals transplanted with MMSCs were markedly increased in comparison with the animals injected with fibroblasts or saline at both mRNA and protein levels. VEGF expression was observed in both transplanted MMSCs and recipient cardiomyocytes by immunofluorescence. Confocal immunofluorescence microscopy revealed the specific markers for cardiomyocytes and endothelial cells in transplanted MMSCs 14 days after transplantation. Vessel count was increased and left ventricular function improved post-MMSC transplantation. These results indicate that transplantation of purified MMSCs from human bone marrow upregulated VEGF expression, enhanced angiogenesis, and improved the functional recovery following myocardial infarction in rats.