静脉及心肌注射骨髓间充质基质细胞未能改善慢性心肌梗死大鼠的心脏功能

背景：有多项研究证明,经静脉或经心肌表面注射移植间充质基质细胞促进了急性心肌梗死后心功能的改善。然而,目前尚缺乏有关经静脉联合经心肌注射移植间充质基质细胞对慢性心肌梗死心脏功能影响的研究。 目的：探讨静脉联合心肌注射骨髓间充质基质细胞对慢性心肌梗死模型大鼠心脏功能的影响及其机制。 方法：体外培养扩增Lewis大鼠的骨髓间充质基质细胞。将3×10⁶ BrdU标记过的骨髓间充质基质细胞分别经股静脉和经心肌表面注射移植于慢性心肌梗死模型大鼠,对照组注射等量PBS。4周后检测两组大鼠心功能的变化,并对大鼠心脏组织行免疫组化染色,观察细胞分化情况及毛细血管数量。 结果与结论：骨髓间充质基质细胞移植4周后,细胞移植组与对照组心功能无明显差别,免疫组化染色提示存留于心肌组织内的移植细胞未分化为心肌细胞,心梗瘢痕区血管密度在细胞移植组和对照组间没有明显差别。结果表明经静脉联合经心肌注射骨髓间充质基质细胞未能改善慢性心肌梗死模型大鼠的心脏功能。 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：     

肾上腺髓质素基因转染增强骨髓间充质干细胞移植对心肌梗死大鼠心室重构及心功能的影响

目的： 研究肾上腺髓质素（ADM）基因转染增强骨髓间充质干细胞（MSCs）移植对心肌梗死大鼠心室重构及心功能的治疗作用。方法：贴壁法体外分离、扩增培养大鼠骨髓间充质干细胞,用X-gal染色测含ADM基因的重组腺病毒(Ad-ADM)对MSCs感染率,ELISA检测Ad-ADM转染后细胞上清液ADM的含量。通过结扎左冠状动脉前降支制备大鼠心肌梗死模型;以DAPI标记细胞通过心肌局部注射移植MSCs;采用生理记录仪测量大鼠的心功能,荧光显微镜观察移植细胞在心脏存活及分布,免疫组化检测ADM在心肌梗死区的表达及心梗区血管密度;天狼猩红染色检测胶原含量,用偏振光显微镜分析Ⅰ/Ⅲ型胶原比率。结果：重组腺病毒对MSCs的转染率与病毒感染复数（MOI）具有量效关系,MOI为150时细胞的感染率达95.4%;转染Ad-ADM后,MSCs可有效表达ADM,7 d时达到表达高峰,与对照组相比明显增加［(26.53±1.42 vs 1.34±0.08) ng/L,P＜0.05］,15 d后与空白对照组无差别［（2.20±1.44 vs 1.52±0.33) ng/L,P＞0.05］;在受体大鼠的心脏切片上有DAPI标记的移植细胞的存活;与对照组及其它组相比,ADM基因修饰的MSCs组心肌梗死区ADM的表达增加;与对照组比较,单纯细胞移植组心梗区新生血管密度增高（P＜0.01）;而与单纯MSCs移植组及单纯Ad-ADM注射组比较,ADM基因修饰的MSCs移植组梗死区血管密度增高更明显（P＜0.05）;单纯MSCs移植组能降低梗死区Ⅰ/Ⅲ型胶原比率（P＜0.01）,并能改善左室功能;与单纯细胞组比较ADM基因修饰的MSCs移植组梗死区Ⅰ/Ⅲ型胶原比率降低更明显（P＜0.05）,而左室功能改善更多。结论：ADM转染的MSCs移植可能通过局部ADM表达的增加,增强MSCs移植的血管新生作用及降低梗死区Ⅰ/Ⅲ型胶原比率,从而增强单纯MSCs细胞移植改善心功能的作用。     

同种异体脂肪组织源性间质干细胞移植治疗大鼠急性心肌梗死

目的：建立体外分离扩增脂肪组织源性间质干细胞方法，并探讨同种异体脂肪干细胞移植治疗大鼠心肌梗死的效果及可行性。方法: 18只雄性SD大鼠随机分为假手术组、急性心肌梗死对照组（AMI组）及AMI+细胞移植组。分离大鼠腹部脂肪组织干细胞，体外扩增，BrdU标记后于结扎左冠状动脉前降支后1h移植入梗死心肌，移植后4周进行血流动力学检测心功能并取出心脏进行病理切片观察和免疫组织化学染色检测移植细胞在梗死心脏中的定居、存活情况。结果: 大鼠腹部脂肪组织可分离培养出大量间质干细胞。细胞移植治疗组左心室收缩压高于AMI对照组（P＜0.01），舒张末压显著降低（P＜0.01），左心室内压最大上升、下降速率明显加快（P＜0.05）；病理组织切片显示梗死边缘区心肌面毛细血管计数明显增加，梗死区心肌组织内及毛细血管壁中均可见移植标记细胞。结论: 脂肪组织可作为干细胞又一新的来源，同种异体脂肪干细胞移植治疗AMI有效、可行。     

同种异体移植骨髓间质干细胞治疗大鼠心梗后心室重构

目的： 观察骨髓间质干细胞（MSCs）移植对大鼠心梗后心室重构和心功能的影响，比较成年大鼠MSCs与乳鼠MSCs移植疗效，初步探讨同种异体移植的可行性。方法: 分别取大鼠和乳鼠的骨髓，体外分离、扩增培养MSCs，Brdu标记。在结扎冠脉后1-2 h 分别将大鼠MSCs和乳鼠MSCs分点注射到异体大鼠心脏梗死边缘区，6周后，采用超声心动图和解剖直测法获得大鼠心功能、心室重构和病理学资料。结果: 细胞移植组左室舒张末期内径和收缩末期内径短于、室壁厚于对照组，重量指数和心室腔都明显小于对照组。组织病理表现细胞移植组心梗区心肌数目多于、血管密度大于对照组，细胞外基质胶原的形成和血管周围胶原沉积均明显少于对照组，心梗区可见Brdu阳性细胞。但大鼠MSCs移植组和乳鼠MSCs移植组间无明显差异。结论: 同种异体骨髓间质干细胞可以在心梗区定植，减少胶原形成，促进心肌和血管生成，从而延缓心梗后心室重构，提高左室收缩和舒张功能。成年鼠干细胞移植与乳鼠干细胞移植具有相似的效果。     

大鼠脂肪干细胞联合碱性成纤维生长因子治疗大鼠心肌梗死

目的 探讨脂肪干细胞（ADSC）联合碱性成纤维生长因子（bFGF）提高心肌梗死大鼠心脏功能的可能机制.方法 SD大鼠50只,先行脂肪干细胞提取手术,分离、培养、鉴定脂肪干细胞,行干细胞成脂、成骨诱导分化,建立大鼠心肌梗死模型,选择缩短分数（FS）＜40％的SD大鼠（36只）,完全随机分4组：单纯注射PBS组（n=9）、单纯注射bFGF组（n=9）、PBS＋ADSC组（n=9）以及ADSC＋bFGF组（n=9）,以bFGF胶为可注射性载体,ADSC为种子细胞,1周后进行大鼠心梗部位移植.移植4周后对心梗面积、左心室室壁厚度、心梗部位微血管密度、ADSC在心梗部位分化情况等指标进行检测,并利用心脏超声对心梗大鼠的心脏功能进行测定.应用免疫组织化学、免疫荧光等方法评价其改善心脏功能可能机制.结果 成功分离ADSC并且通过流式细胞术表明大多数分离的脂肪干细胞CD90抗体阳性、CD29抗体阳性、CD45抗体和CD34抗体阴性.脂肪干细胞能够经过诱导分化成成脂、成骨细胞.PBS＋ADSC组以及ADSC＋bFGF组在室壁厚度、梗死面积、梗死区域微血管形成能力与PBS组相比,差异均有统计学意义,且以ADSC＋bFGF组最为显著（P＜0.01）.ADSC移植到大鼠心脏4周后,可以分化为cTnT阳性细胞、SMA阳性细胞以及vWAg阳性细胞.心功能检测结果表明PBS＋ADSC组同ADSC＋bFGF组一样,具有心梗修复能力.结论 移植ADSC的同时增加bFGF能促进梗死区的心肌再生以及血管化,并能显著改善心脏功能.     

移植转染ADM或HGF基因的骨髓间充质干细胞治疗大鼠心肌梗死

目的探讨移植转染两种不同基因的骨髓间充质干细胞移植治疗大鼠心肌梗死的作用。方法分离、扩增培养大鼠骨髓间充质干细胞;ELISA检测细胞上清液ADM或HGF的含量;制备大鼠心肌梗死模型,心肌局部注射移植经DAPI标记的MSCs;多普勒超声检测大鼠心功能;荧光显微镜观察细胞存活及分布;免疫组化检测新生血管密度及移植细胞在心梗区的分化。结果转染Ad-ADM或Ad-HGF后,MSCs可有效表达ADM或HGF;与单纯MSCs组相比,两基因组细胞均表达TNI,均有connexin 43的表达增加(P<0.05),心梗区新生血管密度增高(P<0.01),左室射血分数(EF)增加(P<0.01);两组间各指标无差别。结论不同基因修饰的MSCs移植均可增强单纯MSCs对心肌梗死大鼠的治疗作用。     

血管内皮生长因子基因转染的心肌细胞移植对心肌梗死大鼠心功能的影响

目的：探讨腺病毒介导血管内皮生长因子165基因（AdVEGF165）转染乳鼠心肌细胞后血管内皮生长因子（VEGF）的表达及移植于大鼠急性心肌梗死（MI）模型后对心功能的影响。方法:体外培养新生大鼠心室肌细胞、标记BrdU、共培养法转染AdVEGF165基因；收集培养液上清，ELISA法检测转染细胞VEGF的表达。结扎同种大鼠前降支建立心肌梗死模型，4周后将心肌梗死大鼠随机分为4组，分别注射移植转染心肌细胞(组Ⅰ)、单纯心肌细胞（组Ⅱ）、AdVEGF165（组Ⅲ）和DMEM培养基（组Ⅳ）。超声心动图检测移植前及移植4周后的心功能。处死大鼠，留取心脏标本作HE病理染色及免疫组化检测，并计数血管密度。结果:AdVEGF165基因转染的心肌细胞表达VEGF高于对照组(P<0.01)；超声检测心功能提示转染细胞组(组Ⅰ)心功能障碍轻于其它3组（P<0.01）；免疫组化检测显示，移植细胞在移植区存活；HE染色血管计数显示转染组(组Ⅰ)有更多的新生血管形成（P<0.01） 。结论：AdVEGF165基因转染心肌细胞后表达分泌VEGF增加，可促进梗死区新生血管形成，改善心肌血供，有利于移植细胞的存活，能更好地减轻心功能障碍。     

自体骨髓单个核细胞移植治疗大鼠后肢缺血

目的　探讨自体骨髓单个核细胞（BM-MNC）移植用于大鼠缺血后肢的治疗后实现血管再生的能力。方法　建立大鼠后肢缺血动物模型,将取于自体的BM-MNC制成细胞悬液注射于缺血部位,分别在移植后2和30d时行动脉造影,用免疫组化方法检测内皮祖细胞（EPC）,毛细血管密度以及测定血管内皮生长因子(VEGF)的表达。结果　缺血肌组织中的EPC含量增高（P<0.01）。BM-MNC移植组在移植早期VEGF表达显著增高（P<0.01）。细胞移植后30dBM-MNC移植组毛细血管密度明显高于其他组（P<0.01）,血管造影可见侧支循环建立。结论　自体骨髓单个核细胞移植于大鼠后肢缺血区能促进血管新生,改善侧支循环,可望成为一种简单有效的治疗下肢缺血的方法。     

胰岛素样生长因子1基因转染胚胎干细胞诱导分化的心肌细胞移植治疗心肌梗死

目的:探讨经逆转录病毒载体介导的胰岛素样生长因子1(IGF-1)基因转染胚胎干细胞(ESC)诱导分化的心肌细胞IGF-1的表达及移植于大鼠慢性心梗模型后对心功能的影响.方法:建立大鼠心梗模型后将心梗大鼠随机分为3组,分别注射移植转染心肌细胞(心肌细胞组)、转染IGF-1基因(IGF-1基因组)和DMEM培养基(DMEM组).取心标本作H-E染色及免疫组织化学检测,并计数血管密度.结果:IGF-1基因转染的心肌细胞表达IGF-1增高,与对照组比较差异有统计学意义;免疫组织化学检测显示,移植细胞在移植区存活;H-E染色血管计数显示转染心肌细胞组有更多的新生血管形成.结论:IGF-1基因转染心肌细胞后表达分泌IGF-1增加,可促进梗死区新生血管形成,有利于移植细胞的存活,能更好地改善心功能.     

经bcl-2基因修饰的骨髓间充质干细胞移植对缺血性心功能不全兔心功能及血管新生的影响

目的:探讨经bcl-2基因修饰的骨髓间充质干细胞(BMSCs)移植对急性心肌梗死家兔心肌细胞凋亡、血管再生及心功能的影响。方法:体外分离、培养、纯化兔BMSCs,分别转染腺病毒及重组腺病毒-Bcl-2。结扎兔冠状动脉前降支制作心肌梗死(MI)模型,2周后于心梗边缘区分别注射等量的腺病毒-Bcl-2-BMSCs(MI+Bcl-2-BMSCs组)、腺病毒-BMSCs(MI+BMSCs组)及DMEM液(MI组)。细胞移植4周后经超声测定心功能;荧光显微镜观察BMSCs的存活及分布;TUNEL法检测心肌细胞凋亡;real-time PCR检测VEGF mRNA表达;免疫组化染色法检测CD31表达,计算新生毛细血管密度。以上数据分别与心功能进行相关性分析。结果:与MI组相比,MI+Bcl-2-BMSCs组和MI+BMSCs组的心功能改善、细胞凋亡率降低、VEGF mRNA表达增多、毛细血管密度增加,其中MI+Bcl-2-BMSCs组的变化更为显著(P0.05)。相关性分析显示左室射血分数与心肌细胞凋亡率呈负相关;与VEGF mRNA的表达量及毛细血管密度呈正相关(P0.01)。结论:经bcl-2基因修饰的BMSCs移植可显著减少缺血性心功能不全兔心肌细胞凋亡、促进血管再生、改善心功能。     

参术冠心颗粒对心肌梗死大鼠冠脉微循环的影响*

 目的：探讨参术冠心颗粒（SSGX）对大鼠心肌梗死(MI)模型冠脉微循环作用。方法：健康SPF级SD大鼠50只,随机分成假手术(sham)组、MI组、SSGX高剂量、中剂量和低剂量治疗组,每组10只。后4组结扎冠状动脉建立MI大鼠模型,假手术组只穿线不进行结扎。造模3 d后超声检查淘汰不合格大鼠,药物干预4周,测定4周后各组大鼠血清心肌损伤标志物、梗死区中小血管平均血管面密度（MVC值）、梗死边缘区血小板内皮细胞黏附分子1(PECAM-1)和血管内皮生长因子(VEGF)表达。结果：MI组与sham组比较,光学显微镜见MI组死亡的心肌纤维间空隙变宽,密集的中型多形核白细胞浸润,肉芽组织增生,坏死心肌纤维被致密的胶原纤维取代。超声可见MI组左室室璧活动异常,射血分数减低。心肌钙蛋白T（cTnT）、MVC、PECAM-1和VEGF各指标与sham组比较均有显著差异（P<0.01）,证明造模成功。大鼠心肌梗死区中小血管的MVC、梗死边缘区PECAM-1及VEGF的表达,SSGX各剂量组与MI组相比表达明显增加,差异有统计学意义（P<0.01）,呈量效关系。但各SSGX组大鼠和MI组大鼠之间,心肌标志物差异无统计学意义（P>0.05）。结论:参术冠心颗粒能改善心肌梗死大鼠冠脉微循环状态,其机制可能与增加PECAM-1和VEGF表达、促进中小血管新生有关。     

Infarct stabilization and cardiac repair with a VEGF-conjugated, injectable hydrogel

Injectable scaffolds made of biodegradable biomaterials can stabilize a myocardial infarct and promote cardiac repair. Here, we describe the synthesis of a new, temperature-sensitive, aliphatic polyester hydrogel (HG) conjugated with vascular endothelial growth factor (VEGF) and evaluate its effects on cardiac recovery after a myocardial infarction (MI). Seven days after coronary ligation in rats, PBS, HG, or HG mixed or conjugated with VEGF (HG + VEGF or HG-VEGF, respectively) was injected around the infarct (n = 8-11/group). Function was evaluated by echocardiography at multiple time points. Pressure-volume measurements were taken and infarct morphometry and blood vessel density were assessed at 35 days after injection. HG-VEGF provided localized, sustained VEGF function. Compared with outcomes in the PBS group, fractional shortening, ventricular volumes, preload recruitable stroke work, and end-systolic elastance were all preserved (p < 0.05) in the HG and HG + VEGF groups, and further preserved in the HG-VEGF group. Conjugated VEGF also produced the highest blood vessel density (p < 0.05). The infarct thinned and dilated after PBS injection, but was smaller and thicker in hearts treated with HG (p < 0.05). Our temperature-sensitive HG attenuated adverse cardiac remodeling and improved ventricular function when injected after an MI. VEGF delivery enhanced these effects when the VEGF was conjugated to the HG.     

Synergistic effect of adipose-derived stem cell therapy and bone marrow progenitor recruitment in ischemic heart

Human multipotent adipose-derived stem cells (hMADSCs) have recently been isolated featuring extensive expansion capacity ex vivo. We tested the hypothesis that hMADSC transplantation might contribute to cardiac functional recovery by its direct or indirect effect on myocardial infarction (MI). Nude rats were either transplanted with hMADSCs or PBS (control) in ischemic myocardium immediately following MI. Echocardiographical assessment of cardiac function after MI with hMADSCs showed significant improvement of each parameter compared to that with PBS. Histological analysis also showed significantly reduced infarct size and increased capillary density in peri-infarct myocardium by hMADSC treatment. However, remarkable transdifferentiation of hMADSCs into cardiac or vascular lineage cells was not observed. Despite the less transdifferentiation capacity, hMADSCs produced robust multiple pro-angiogenic growth factors and chemokines, such as vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and stromal cell-derived factor-1α (SDF-1α). Specifically, hMADSC-derived SDF-1α had a crucial role for cooperative angiogenesis, with the paracrine effect of hMADSCs and Tie2-positive bone marrow (BM) progenitor recruitment in ischemic myocardium. hMADSCs exhibit a therapeutic effect on cardiac preservation following MI, with the production of VEGF, bFGF, and SDF-1α showing paracrine effects and endogenous BM stem/progenitor recruitment to ischemic myocardium rather than its direct contribution to tissue regeneration.     

Isosorbide dinitrate improves the efficacy of bone mesenchymal stem cell transplantation via endothelial nitric oxide synthase-dependent mechanism

This study investigated the effect of treatment wientry isosorbide dinitrate (Isoket) on bone mesenchymal stem cell (BMSC) transplantation in a rat model of myocardial infarction (MI) and its possible mechanism. Sprague-Dawley (SD) rats were randomized to a sham operation group, MI control group, BMSC transplantation group, and Isoket-BMSCs transplantation group. Isosorbide dinitrate (Isoket, 5?μg/m) was administered by intraperitoneal injection (10?ml/kg) at 0, 12, and 24?hours following ischemia/reperfusion induction of MI models. Left ventricular function, myocardial infarct size (MIS), the survival of engrafted BMSCs, and expression of vascular endothelial growentry factor (VEGF), inducible nitric oxide synthase (iNOS), and endothelial nitric oxide synthase (eNOS) proteins were detected 2?weeks post-transplantation. The results showed isosorbide dinitrate attenuated cardiac dysfunction, increased the survival of engrafted cells in the ischemic heart and promoted iNOS, eNOS, and VEGF protein expression. It is suggested that isosorbide dinitrate enhances mesenchymal stem cell therapy for MI via an eNOS-dependent mechanism.     

不同时间移植人脐血CD34+细胞可影响心肌梗死大鼠心功能及血管内皮细胞生长因子的分泌

背景：干细胞移植可以改善心脏功能,改善预后。 目的：观察不同时间经静脉移植人脐血CD34+细胞对心肌梗死大鼠心功能及细胞因子分泌的影响。 方法：结扎冠状动脉左前降支制备Wistar大鼠心肌梗死模型,于梗死后1,5,10 ,30 d经尾静脉注入0.5 mL人脐血CD34+细胞(实验组)或磷酸盐缓冲溶液(对照组)。 结果与结论：与对照组相比,梗死后5,10 d实验组大鼠左室射血分数明显升高(P < 0.05),左室收缩末内径明显减小(P < 0.05),左室后壁增厚率更高(P < 0.05),毛细血管密度明显增加(P < 0.05),且以梗死后10 d移植大鼠心功能改善效果最明显(P < 0.05)。梗死后10 d实验组心肌局部血管内皮细胞生长因子最高(P < 0.05)。说明大鼠心肌梗死后5,10 d经静脉移植脐血CD34⁺细胞可明显改善心功能,梗死后10 d移植血管内皮细胞生长因子分泌更多,血管生成更多,对心功能的改善更明显;同时说明脐血单个核细胞移植可能是通过增加血管内皮细胞生长因子分泌,提高毛细血管密度来改善心功能的。     

The T-type calcium channel blocker mibefradil reduced interstitial and perivascular fibrosis and improved hemodynamic parameters in myocardial infarction-induced cardiac failure in rats

Fibrillar collagen accumulates within the interstitium and around coronary arteries following cardiac failure and is responsible for abnormal myocardial stiffness and reduced coronary performance associated with impaired cardiac function. The aim of the study was to determine the effects of long-term treatment with the T-type calcium channel antagonist mibefradil on myocardial remodeling and cardiac function after chronic myocardial infarction (MI). MI was induced by permanent ligation of the left coronary artery in male Wistar rats. Animals were assigned to sham-operated, placebo-treated or mibefradil-treated (10 mg/kg per day p.o.) MI groups. Treatment with mibefradil was started either 7 days before, 24 h after, or 7 days after ligation and continued for 6 weeks after MI. At this time point, mean arterial blood pressure (MAP), heart rate (HR), left ventricular end-diastolic pressure (LVEDP) and cardiac contractility (dP/dt_max) were measured in conscious rats. Morphometric parameters were determined in picrosirius red-stained hearts: total heart weight (THW), interstitial and perivascular collagen volume fraction (ICVF, PCVF), myocardial infarct size (IS), vascular perimeter (VP), inner vascular diameter (IVD) and media thickness (MT). Six weeks after MI, MAP and dP/dt_max were decreased, and LVEDP was increased in placebo-treated animals. In mibefradil-treated animals whose treatment started 7 days before or 24 h after MI, MAP and dP/dt_max were higher, and LVEDP was lower than in placebo-treated controls. THW, ICVF, PCVF and MT were higher in placebo-treated animals. Mibefradil treatment resulted in higher ICVF and IS, higher VP and IVD (when started 7 days before MI) and lower PCVF and MT (when started 7 days before or 24 h after MI) than were observed in placebo-treated controls. Chronic treatment with mibefradil reduced interstitial and perivascular fibrosis and improved cardiac function in MI-induced heart failure in rats. Cardiac remodeling was best prevented when treatment was begun before the ischemic event. Received: 16 March 1999 / Accepted: 23 August 1999     

Human dental pulp stem cells improve left ventricular function, induce angiogenesis, and reduce infarct size in rats with acute myocardial infarction

Human dental pulp contains precursor cells termed dental pulp stem cells (DPSC) that show self-renewal and multilineage differentiation and also secrete multiple proangiogenic and antiapoptotic factors. To examine whether these cells could have therapeutic potential in the repair of myocardial infarction (MI), DPSC were infected with a retrovirus encoding the green fluorescent protein (GFP) and expanded ex vivo. Seven days after induction of myocardial infarction by coronary artery ligation, 1.5 x 10(6) GFP-DPSC were injected intramyocardially in nude rats. At 4 weeks, cell-treated animals showed an improvement in cardiac function, observed by percentage changes in anterior wall thickening left ventricular fractional area change, in parallel with a reduction in infarct size. No histologic evidence was seen of GFP+ endothelial cells, smooth muscle cells, or cardiac muscle cells within the infarct. However, angiogenesis was increased relative to control-treated animals. Taken together, these data suggest that DPSC could provide a novel alternative cell population for cardiac repair, at least in the setting of acute MI.     

骨髓间充质干细胞膜微粒促进大鼠心肌梗死后血管新生

目的:观察骨髓间充质干细胞膜微粒(MSC-MPs)对大鼠心肌梗死后血管新生以及心功能的影响。方法:提取Sprague-Dawley大鼠MSCs并培养,在低氧低营养条件下培养72 h,以诱导细胞凋亡释放MSC-MPs。将培养上清液超速离心获取MSC-MPs,透射电镜下观察其大小及形态,并用流式细胞术分析其表型。建立SD大鼠心肌梗死模型,心肌梗死边缘区注射膜微粒及对照试剂。超声心动图检测心功能,Masson染色检测心梗面积,免疫组织化学染色技术检测梗死边缘区血管α-平滑肌肌动蛋白和von Willebrand因子以确定血管新生情况,real-time PCR检测心梗组织中血管内皮生长因子(VEGF)表达变化。结果:MSCs凋亡后可以释放膜微粒,MSC-MPs来自MSCs,直径为100~1 000 nm。心肌梗死大鼠心肌内注射MSC-MPs后,第7天和第28天时心功能明显改善,第28 d时心梗面积比对照组减小,新生血管密度明显增加,第7天时心梗组织VEGF的表达增加。结论:MSC-MPs可以促进大鼠心肌梗死后的血管新生,改善心功能。     

血红素氧合酶-1修饰的骨髓间充质干细胞心肌移植对梗死后心肌细胞凋亡及左心室功能的影响

目的： 探讨血红素氧合酶-1(HO-1)修饰的骨髓间充质干细胞(MSCs)对心肌梗死后心肌细胞凋亡及左心室功能的影响。方法: 取大鼠骨髓,体外分离扩增培养MSCs,HO-1腺病毒转染。结扎左前降支1 h后,分别将HO-1-MSCs、MSCs多点注射到大鼠心脏梗死区周边,对照组注射等量PBS。移植后第4 d,Western blotting检测梗死区周边HO-1蛋白、促凋亡蛋白Bax的表达;ELISA检测梗死区周边组织细胞因子血管内皮生长因子(VEGF)、b-成纤维生长因子(bFGF)的表达,第7 d超声心动图检测各组大鼠心功能变化。4周后,取梗死区周边心肌行Masson染色和免疫组化CD34因子染色。结果: Adv-HO-1转染MSCs后获稳定表达;HO-1蛋白在HO-1-MSCs组的表达明显高于MSCs组和对照组(P<0.01);促凋亡蛋白Bax的表达明显低于其它2组(P<0.01);细胞因子VEGF、bFGF的表达不同程度地高于其它2组(P<0.01)。HO-1-MSCs组左室收缩功能各项指标明显优于其它2组(P<0.01)。移植4周后,HO-1-MSCs组梗死区周边毛细血管密度明显高于MSCs组和对照组(P<0.01),HO-1-MSCs组心室壁变厚,心室腔明显缩小,胶原蛋白沉积减少。结论: HO-1修饰的MSCs分泌细胞因子协同HO-1蛋白抑制心肌细胞凋亡,促血管新生,抑制心室重构,改善心功能。