大鼠骨髓间充质干细胞移植后肝内定居的实验研究

目的探索大鼠骨髓间充质干细胞(MSCs)同种异体移植后在受体大鼠模型肝内定居分布情况。方法利用密度梯度离心法分离、纯化培养大鼠骨髓间充质干细胞。取第三代MSCs经CFSE标记后从门静脉植入同种异体正常组和肝损伤组大鼠体内,于移植后的第14d取出的肝脏,通过冰冻切片行荧光检测,研究MSCs在大鼠肝脏内定居分布情况。结果经门静脉移植的MSCs在正常组和肝损伤组的肝脏内均能定居,且定居的细胞数量上肝损伤组明显多于正常组。结论经门静脉移植的MSCs可以定居于肝脏内,且定于肝脏的干细胞数量与肝脏是否损伤密切相关。     

骨髓间充质干细胞移植对心肌梗死大鼠损伤心肌的修复效果

目的 探讨骨髓间充质干细胞(BMSCs)移植对心肌梗死大鼠损伤心肌的修复效果,为进一步提高BMSCs移植治疗心肌梗死的疗效提供实验依据.方法 将22只大鼠参照Olivette方法制作心肌梗死模型,共16只进入实验终点,随机分为2组:对照组(C组,n=8)梗死区注射P BS;骨髓间充质干细胞移植组(M组,n=8)梗死区注射BMSCs.术后喂养4周,行心脏彩超,取心脏组织,荧光显微镜观察BMSCs的分布、分化及梗死区毛细血管密度.结果 标记CM-Dil和cTnT免疫组织化学染色双重阳性的心肌样细胞在梗死区分布.与C组相比,M组大鼠左室收缩末期内径(LVEDd)、左室舒张末期内径(LVEDs)、射血分数(EF)、左室短轴缩短率(FS)均有明显改善(P＜0.05),毛细血管密度明显增加(P＜0.05).结论 BMSCs可在心肌梗死的大鼠心脏分化为心肌样细胞,提高梗死区毛细血管密度,改善心功能.     

静脉移植骨髓干细胞治疗大鼠急性心肌梗死

目的　探讨急性心肌梗死 (AMI)早期经静脉途径移植骨髓基质干细胞对心功能的影响。方法　大鼠急性心肌梗死模型通过结扎冠状动脉前降支制作。同种异体大鼠骨髓基质干细胞体外培养、扩增、标记 ,并通过尾静脉于心肌梗死后 1d移植入AMI大鼠体内。分别进行心脏超声检查 ,以及组织学和免疫化学检测。结果　心肌梗死3周后 ,免疫组化分析表明部分干细胞迁移至梗死心肌周围并存活下来 ;干细胞移植组大鼠心功能较移植前及对照组明显改善 (P <0 0 5 )。结论　心肌梗死后 1d经静脉移植的骨髓基质干细胞可以归巢至梗死心肌处 ,并且可以改善损伤的心功能。     

移植时机对骨髓间充质干细胞修复梗死心肌的影响

目的:观察心肌梗死后不同炎症微环境对骨髓间充质干细胞(MSCs)移植后在大鼠梗死心肌中的定位、存活及分化情况,探讨细胞治疗的最佳时间窗. 方法:建立大鼠左冠状动脉结扎的心肌梗死模型,心肌梗死后1 h及1,2,4,8 wk分别取心脏进行组织学观察;将经过4',6-二脒-2-苯基吲哚(4',6-diamidino-2-phenylindole, DAPI)标记的同种骨髓间充质干细胞在心肌梗死后1 h及1,2,4,8 wk移植到心肌梗死边缘区(每组n=10),对照组心肌梗死后1 h注射等量培养基(n=10). 心肌梗死后不同时间点采集心脏标本进行HE染色观察炎症反应的变化,细胞移植治疗各组在心肌梗死后8 wk测定心脏功能、心脏瘢痕面积以及免疫组化染色鉴定细胞分化情况. 结果:分离纯化的大鼠MSCs经流式细胞术鉴定为CD44 CD90 /CD34-CD45-CD31-,心肌梗死后1 wk梗死相关区的炎症反应较强,2 wk时减弱, 4～8 wk时瘢痕完全形成并出现左室重塑. 1 wk移植组未发现有移植细胞存活, 左室心功能及瘢痕面积百分比与对照组相似,1 h及2,4 wk细胞移植组心肌组织冰冻切片中可观察到大量标记细胞存在,并向周围迁移分布,免疫组化显示阳性标记细胞desmin, ctnI 阳性,左室血流动力学指标及瘢痕面积百分比与对照组比较均有改善(P<0.05), 2 wk的左室收缩末压力、左室最大上升速率及瘢痕面积百分比的改善优于1 h组和4 wk移植组(P<0.05). 结论:心肌梗死后炎症反应强烈, 不利于移植细胞的存活,而在炎症减弱的瘢痕修复早期尽早进行MSCs移植可能对于细胞的存活及心功能的恢复较为有利.     

骨髓单个核细胞经冠状动脉移植治疗心肌梗死的实验研究

目的:观察同基因骨髓单个核细胞经冠状动脉植入心脏后的分布及分化状况。方法:用雄性近交系Lew is大鼠作为模型动物。首先,在大鼠颈部异位心脏移植模型基础上,以冷冻法制备急性心肌梗死模型。其次,心肌梗死模型建立2 d后,分离、纯化大鼠骨髓单个核细胞,并以PKH26红色荧光染料标记。然后,经移植心脏冠状动脉输注PKH26标记的同基因骨髓单个核细胞(实验组)和DMEM培养液(对照组)。最后,细胞移植7 d后,采集各标本,检测植入细胞分布及分化状况。结果:病理检查证实冷冻区域心肌变性坏死且界线清楚。利用该模型成功的模拟了临床经冠状动脉输注自体骨髓单个核细胞的治疗方法。PKH26红色荧光阳性细胞主要集中于实验组大鼠移植心脏的冷冻梗死区,脾脏、骨髓也可见少量阳性细胞分布,移植心脏的非梗死区及其余脏器组织切片均未见红色荧光阳性细胞;梗死区内PKH26标记的细胞部分表达CD34;梗死区内connexin43的表达明显高于对照组。结论:供者同基因骨髓单个核细胞经冠状动脉移植后,能够存活并定向迁移至心肌损伤区域,并且可能促使梗死区出现心肌再生。     

Y染色体追踪大鼠骨髓间充质干细胞心肌移植的实验研究

目的 利用Y染色体检测雄性大鼠的骨髓间充质干细胞(MSCs)移植到雌性大鼠心肌梗死模型中的存活情况。方法 采用全骨髓贴壁筛选法体外培养雄性大鼠的骨髓间充质干细胞作为移植细胞,选取80只雌性大鼠通过结扎左冠状动脉前降支制备心肌梗死模型,其中45只成功建立模型。成模后2周按以下分组进行细胞移植：将模型动物随机分为心外膜直接注射MSCs组(A组,n=15)、经静脉移植MSCs组(B组,n=15)和经静脉注射等量DMEM培养液组(C组,n=15),通过实时定量PCR检测雄性大鼠Y染色体特有的SRY基因,观察移植后1d、1周、2周及3周时MSCs在梗死心肌的存活情况。结果 经心外膜直接注射组和经静脉移植组通过PCR均可检测出SRY基因的存在,移植后两组的心功能得到明显的改善(P<0.05)。结论 MSCs经心外膜和静脉移植均可分布于心肌梗死周围区域,对梗死后大鼠的心脏具有保护作用。     

大鼠急性心肌梗死区同种异体骨髓单个核细胞移植观察

目的:探讨同种异体骨髓单个核细胞(BM-MNCs)在急性心肌梗死区分化增殖潜能及其修复重建心肌作用,为细胞移植治疗急性心肌梗死提供新种子细胞.方法:健康雄性Wistar大鼠20只,随机分为急性心肌梗死对照组(10只)和急性心肌梗死实验组(10只).用结扎冠状动脉左前降支的方法建立大鼠心肌梗死模型,分别将培养基和制备的BM-MNCs悬液心外膜下植入梗死心肌周围,移植术后4周,观察心肌梗死区及其周边区组织形态学特点、心肌梗死面积变化.结果:移植术后4周,实验组与对照组相比心肌梗死面积缩小(P＜0.01);实验组心肌梗死区内有BrdU标记阳性的BM-MNCs移植细胞存活,向心肌源性细胞分化并且诱导了大量的新生毛细血管.结论:同种异体BM-MNCs在细胞水平完成了对心肌梗死区再心肌化和再血管化过程,是治疗急性心肌梗死的理想种子细胞.     

骨髓单个核细胞移植可影响急性心肌梗死后心室重构

目的 观察同种异体骨髓单个核细胞(bone marrow mononuclear cells, BM-MNCs)移植对大鼠急性心肌梗死后左心室重构的影响.方法 健康雄性Wistar大鼠40只,随机均分为对照组和实验组.分别将制备的培养基和BM-MNCs悬液经心外膜下种植对照组和实验组梗死心肌周围.结果 移植术后4周,实验组左心室非梗死区心肌骨桥蛋白基因(OPN mRNA)、Ⅰ型胶原和AngⅡ含量均显著低于对照组(P均<0.05).Pearson直线相关分析表明,实验组和对照组心肌AngⅡ、Ⅰ型胶原与OPN mRNA三者之间两两均呈正相关(P均<0.05).结论 同种异体骨髓单个核细胞移植可能通过抑制大鼠心肌Ⅰ型胶原合成,下调心肌AngⅡ和OPN基因表达,减轻左心室重构.     

SDF-1/CXCR4轴介导大鼠骨髓间充质细胞向心肌梗死组织迁徙的体外实验研究

目的研究基质细胞衍生因子1（SDF-1）／CXCR4轴在骨髓间充质细胞迁徙到梗死心肌中的作用。方法全骨髓贴壁法培养骨髓间充质细胞，结扎SD大鼠左前降支制作急性心肌梗死模型并制备正常和梗死心肌组织提取液，利用Boyden小室体外迁移体系观察不同浓度SDF-1和心肌组织提取液对骨髓间充质细胞的趋化作用，及AMD3100处理骨髓间充质细胞对心肌组织提取液趋化骨髓间充质细胞的影响。结果成功培养了骨髓间充质细胞并建立了大鼠急性心肌梗死模型。SDF-1对骨髓间充质细胞有剂量依赖性的趋化作用，梗死1周的心肌组织提取液对骨髓间充质细胞有明显的趋化作用，而这种作用可部分被SDF-1受体CXCR4的阻断剂AMD3100抑制。结论梗死心肌组织提取液对骨髓间充质细胞有明显的趋化作用，SDF1／CXCR4可能是梗死心肌组织提取液中趋化骨髓间充质细胞的主要趋化因子／受体对。     

老年骨髓基质细胞移植治疗急性心肌梗死实验研究

目的 :观察老年大鼠骨髓基质细胞 (MSC)能否在急性心肌梗死环境中存活、增殖和向心肌样细胞分化。方法 :选用老年近交系Wistar大鼠 ,取供体鼠MSC ,体外扩增 ,DAPI荧光标记。受体鼠经左冠状动脉结扎建立急性心肌梗死模型。 1周后将标记的MSC用直接注射方式移植到梗死灶中 ,移植后 3、7、14d取材 ,观察梗死灶中MSC分布、扩散及心肌特异性蛋白T(TnT)的表达。结果 :在不同移植时间梗死灶中都发现DAPI阳性的细胞 ,且细胞计数随移植时间延长而增多。部分细胞表达TnT ,其中少数细胞出现心肌样横纹。结论 :老年大鼠MSC可在急性心肌梗死环境中存活、增殖 ,有向心肌样细胞分化的能力。     

骨髓间质干细胞联合抗炎治疗大鼠急性心肌梗死的实验研究

目的 :观察静脉移植骨髓间质干细胞 (MSC)及早期抗炎治疗心肌梗死的可能性及对心肌梗死后心功能的影响。方法 :大鼠骨髓间质干细胞 (rMSC)培养后 ,制备成悬液备用。 3 7只SD大鼠均结扎冠状动脉左前降支 ,建立急性心肌梗死模型后 ,随机分为 4组 :ArMSC加地塞米松组 (n =10 ) ;BrMSC组 (n =10 ) ;C地塞米松组 (n =10 ) ;D心肌梗死对照组 (n =7只 )。 4周后 ,观察心脏的结构、功能改变。结果 :与对照组及地塞米松组相比 ,rMSC加地塞米松组、干细胞组的左室结构与功能明显改善 (P <0 .0 5 ) ,干细胞组低于地塞米松加干细胞组 (P <0 . 0 5 ) ,地塞米松组与对照组无明显差别 (P >0. 0 5 )。结论 :骨髓间质干细胞联合抗炎治疗心肌梗死取得了良好的效果     

心肌球源性心肌干细胞联合心室肌细胞外基质治疗大鼠急性心肌梗死效果

目的拟研究心室肌细胞外基质（ECM）能否促进植入心肌梗死心肌组织内的心肌球源性心肌干细胞（CDC）向心肌细胞, 血管内皮及血管平滑肌细胞分化,改善大鼠心肌梗死后的心脏结构及功能。方法心肌组织块培养法培养CDC,脱细胞法配置 ECM,结扎Wistar 大鼠前降支建立急性心肌梗死模型。分别向心肌梗死心肌组织内注入IMDM（I 组）,ECM悬液（E组）,含 106CDCs的IMDM溶液（IC 组）,含106CDCs的ECM悬液（EC组）,每组心肌梗死大鼠6 只。3 周后心脏彩超评估心脏功能, Masson染色分析心肌纤维化阳性面积百分比,免疫荧光定性分析CDC在体表达vWF,α-SA,α-SMA。结果心肌梗死3周后, EC组左室射血分数及短轴缩率（FS%）最高;EC组心肌梗死后心肌纤维化阳性面积百分比最低;EC组CDC向内皮,心肌及平滑 肌细胞的分化阳性面积百分比较高,P<0.05。结论心肌组织源性的ECM能够促进植入心肌梗死组织内的CDC向心肌,内皮 及平滑肌细胞分化。联合移植CDC及ECM能够取得最佳的心脏结构及功能上的益处。     

Effects of Tongxinluo-facilitated cellular cardiomyoplasty with autologous bone marrow-mesenchymal stem cells on postinfarct swine hearts

Background  Treatment of ischemic heart disease remains an important challenge, though there have been enormous progresses in cardiovascular therapeutics. This study was conducted to evaluate whether Tongxinluo (TXL) treatment around the transplantation of mesenchymal stem cells (MSCs) can improve survival and subsequent activities of implanted cells in swine hearts with acute myocardial infarction (AMI) and reperfusion.
Methods  Twenty-eight Chinese mini-pigs were divided into four groups including a control group (n=7); group 2, administration of low-dose TXL alone from the 3rd day prior to AMI to the 4th day post transplantation (n=7); group 3, MSCs alone (n=7) and group 4, TXL + MSCs (n=7). AMI models were made by occlusion of the left anterior descending coronary artery for 90 minutes. Autologous bone marrow-MSCs (3×10⁷ cells/animal) were then injected into the post-infarct myocardium immediately after AMI and reperfusion. The survival and differentiation of implanted cells in vivo were detected by immunofluorescent analysis. The data of cardiac function were obtained at baseline (1 week after transplantation) and endpoint (6 weeks after transplantation) by single photon emission computed tomography (SPECT) and magnetic resonance imaging (MRI). Apoptosis was detected by TUNEL assay and the oxidative stress level was investigated in the post-infarct myocardium at endpoint.
Results  At endpoint, there was less fibrosis and inflammatory cell infiltration with more surviving myocardium in group 4 than in the control group. In group 4 the survival and differentiation of implanted MSCs were significantly improved more than that seen in group 3 alone (P<0.0001); the capillary density was also significantly greater than in the control group, group 2 or 3 both in the infarcted zone (P<0.0001) and the peri-infarct zone (P<0.0001). MRI showed that parameters at baseline were not significantly different between the 4 groups. At endpoint, regional wall thickening and the left ventricular ejection fraction were increased while the left ventricular mass index, dyskinetic segments and infarcted size were decreased only in group 4 compared with control group (P<0.0001). SPECT showed that the area of perfusion defect was significantly decreased at endpoint only in group 4 compared with control group (P<0.0001). TUNEL assay indicated that TXL administration significantly decreased cell apoptosis in peri-infarct myocardium in groups 2 and 4. Furthermore, superoxide dismutase (SOD) significantly increased and malondialdehyde (MDA) decreased in groups 2 and 4 by the administration of TXL.
Conclusions  Our study demonstrates the following: (1) immediate intramyocardial injection of MSCs after AMI and reperfusion resulted in limited survival and differentiation potential of implanted cells in vivo, thus being incapable of beneficially affecting post-hearts; (2) TXL-facilitation resulted in a significant survival and differentiation potential of implanted cells in vivo via inhibition of apoptosis and oxidative stress, accompanied by significant benefits in cardiac function.

     

Myocardial autophagy variation during acute myocardial infarction in rats: the effects of carvedilol

Background The loss of cardiac myocytes is one of the mechanisms involved in acute myocardial infarction （AMI）-related heart failure. Autophagy is a common biological process in eukaryote cells. The relationship between cardiac myocyte loss and autophagy after AMI is still unclear. Carvedilol, a non-selective α1-and β-receptor blocker, also suppresses cardiac myocyte necrosis and apoptosis induced by ischemia. However, the association between the therapeutic effects of carvedilol and autophagy is still not well understood. The aim of the present study was to establish a rat model of AMI and observe changes in autophagy in different zones of the myocardium and the effects of carvedilol on autophagy in AMI rats. Methods The animals were randomly assigned to a sham group, an AMI group, a chloroquine intervention group and a carvedilol group. The AMI rat model was established by ligating the left anterior descending coronary artery. The hearts were harvested at 40 minutes, 2 hours, 24 hours and 2 weeks after ligation in the AMI group, at 40 minutes in the chloroquine intervention group and at 2 weeks in other groups. Presence of autophagic vacuoles （AV） in the myocytes was observed by electron microscopy. The expression of autophagy-, anti-apoptotic- and apoptotic-related proteins, MAPLC-3, Beclin-1, Bcl-xl and Bax, were detected by immunohistochemical staining and Western blotting. Results AVs were not observed in necrotic regions of the myocardium 40 minutes after ligation of the coronary artery. A large number of AVs were found in the region bordering the infarction. Compared with the infarction region and the normal region, the formation of AV was significantly increased in the region bordering the infarction （P 〈0.05）. The expression of autophagy- and anti-apoptotic-related proteins was significantly increased in the region bordering the infarction. Meanwhile, the expression of apoptotic-related proteins was significantly increased in the infarction region. In the chloroquine intervention group, a large number of initiated AVs （AVis） were found in the necrotic myocardial region. At 2 weeks after AMI, AVs were frequently observed in myocardial cells in the AMI group, the carvedilol group and the sham group, and the number of AVs was significantly increased in the carvedilol group compared with both the AMI group and the sham group （P 〈0.05）. The expression of autophagy- and anti-apoptotic-related proteins was significantly increased in the carvedilol group compared with that in the AMI group, and the positive expression located in the infarction region and the region bordering the infarction. Conclusions AMI induces the formation of AV in the myocardium. The expression of anti-apoptosis-related proteins increases in response to upregulation of autophagy. Carvedilol increases the formation of AVs and upregulates autophagy and anti-apoptosis of the cardiac myocytes after AMI.     

The vascular endothelial growth factor expression and vascular regeneration in infarcted myocardium by skeletal muscle satellite cells

Skeletal satellite cell normally lies in a quiescent state under the basal membrane of skeletal muscular fibers. Once injury occurred, it will rapidly mobilize, proliferate and fuse to repair the damaged fiber.1 Skeletal myoblast transplantation has been shown to improve cardiac function in infarcted myocardium models. Vascular endothelial growth factor (VEGF) is a promising reagent for inducing myocardial angiogenesis and hypoxia is also a major inducer of VEGF expression. Some studies pr…     

骨髓干细胞植入正常或慢性梗死心肌后短期内移植细胞的分布及可利用度

目的采用心肌内注射方法将骨髓间充质干细胞(BMSCs)植入到正常或慢性梗死心肌中后, 研究短期内植入细胞的分布和可利用度。方法采用选择性冠状动脉结扎方法建立大鼠慢性心肌梗死模型( n =9) 。1个月后, 采用心肌内注射方法将 111 铟 - 羟基喹啉 ( 111Indium- oxine, 111In) 同位素标记的自体 BMSCs (2×106/50μL)植入到慢性梗死心肌和正常对照心肌中( n =6) 。采用序列平面针孔闪烁扫描方法测定 BMSCs移植后 2 h、1 d、3 d、7 d 时的心肌 111In 的放射活性, 并计算植入细胞在心肌内的驻留率。于细胞移植术后第 7 天切取制备心脏横断面冷冻切片, 进行组织放射微成像(Micro- imaging)和组织病理学分析, 观察植入细胞在心肌内的分布情况。结果慢性心肌梗死(MI)组的心肌 111In 的放射活性在所有测定的时间点均显著高于正常对照组(P<0.01)。心肌放射强度实测值在经由各相应时间点 BMSCs细胞 111In 的自发泄漏率的体外标定值校正后, 计算得出植入的 BMSCs 细胞在慢性梗死心肌(MI 组)中的驻留率平均为 60%, 而在正常对照组心肌中细胞的驻留率只有 25%(P <0.01), 并在 7 d 的随访期中保持稳定。组织放射微成像和组织病理学分析都证实植入的 BMSCs 主要分布于由注射针头插入损伤或慢性心肌梗死所造成的纤维瘢痕组织中。结论心肌内细胞移植术后 7 d 内,被植入到慢性梗死心肌中的 BMSCs 细胞的可利用度高于被植入在正常心肌中的 BMSCs 细胞的可利用度。植入心肌内的 BMSCs 主要分布于由注射针头插入损伤和慢性心肌梗死导致的纤维瘢痕组织中。     

TIMP-3基因转染血管平滑肌细胞移植对大鼠急性心肌梗死后心脏结构的影响

目的研究基质金属蛋白酶组织抑制因子3（tissue inhibitor-3 of matrix metalloproteinases, TIMP- 3 ）基因转染血管平滑肌细胞（vascular smooth muscle cells,VSMCs）移植,对急性心肌梗死（acute myocardial infarction, AMI）后早期心脏结构变化的影响,并探讨其可能的机制。方法取Wistar大鼠胸主动脉采用组织块贴壁法培养VSMCs。另取54只Wistar雌性大鼠建立左冠状动脉远端结扎的AMI动物模型,随机分三组。冠状动脉结扎后立即向缺血部心室壁内注射含有1×10^6个TIMP-3基因转染VSMCs（A组）,1×10^6个VSMCs（B组）或不舍细胞的DMEM液（C组）,各0．5ml。术后3天,进行心脏形态学检测观察大鼠心脏结构变化,免疫组化染色验证TIMP-3基因转染VSMCs在缺血心肌中的存活情况,RT—PCR法测定大鼠缺血心肌TIMP-3和基质金属蛋白酶9（matrix metalloproteinase 9,MMP-9）mRNA含量。结果成功分离、培养VSMCs,纯度达98％,TIMP-3基因成功转入VSMCs中。术后3天,A组的左心室容积较正常鼠升高（P〈0．01）,但小于B（P〈0．01）组和C组（P〈0．01）,B组小于C组（P〈0．01）。A组的左心室客积指数较正常组有所上升（P〈0．01）,但小于B和C组（P〈0．01）。免疫组化染色见TIMP-3基因转染VSMCs被成功植入缺血心肌并在其中存活。RT—PCR结果显示：各移植组TIMP-3mRNA含量均较对照组显著升高（P〈0．01）,A组较B组、C组明显增高（P〈0．01）,B组较C组增高（P〈0．01）;A组MMP-9mRNA含量较B组、C组明显降低（P〈0．01）,B组较C组降低（P〈0．01）。结论将TIMP-3基因转染的VSMCs移植入心肌缺血区可明显抑制MMP-9的表达,进而抑制AMI后早期心肌重塑,改善心功能。     

骨骼肌干细胞移植抑制缺血心肌纤维化的实验研究

目的 观察自体骨骼肌干细胞移植于缺血心肌纤维化的抑制作用。方法 取12只成年犬臀大肌,分离卫星细胞,培养、传代、用4‘,6-二乙酰基－2－苯基吲哚（DAPI）标记卫星细胞;在已建立的犬急性心肌梗死动物模型基础上;将DAPI标记的卫星细胞,自左冠状动脉前降支灌入缺血心肌中。分别于2、4、8周后取出心脏,对缺血心肌的纤维化程度及植入的卫星细胞进行观察,并设对照组。结果 卫星细胞在缺血心肌中可分化成心肌细胞样细胞;在卫星细胞移植区域,心肌细胞的纤维化被有效抑制;对照组缺血心肌发生玻璃样变性,心肌细胞基本结构紊乱。结论 自体骨骼肌卫星细胞在缺血心肌中可分化成心肌细胞样细胞,并可抑制血心肌的纤维化;骨骼肌干细胞移植有望为心肌损伤提供一样新的治疗途径。     

基质金属蛋白酶组织抑制因子-3基因转染血管平滑肌细胞移植对大鼠心肌梗死的治疗作用

目的 观察基质金属蛋白酶组织抑制因子3(TIMP-3)基因转染血管平滑肌细胞(VSMCs)移植,对大鼠心肌梗死(AMI)的治疗效果,并探讨其可能的机制.方法 取Wistar大鼠胸主动脉,采用组织块法培养VSMCs.左冠状动脉远端结扎方法复制AMI模型.随机分三组:冠状动脉结扎后3d向缺血心室壁内分别注射含有1×106个TIMP-3基因转染的VSMCs(TIMP-3组)、1×106个VSMCs(VSMC组)、不含细胞的DMEM液(DMEM组)各0.5mL.术后第4周,观察大鼠心脏功能变化,免疫组化染色检测TIMP-3和基质金属蛋白酶2(MMP-2)的表达,RT-PCR法检测缺血心肌组织中TIMP-3和MMP-2 mRNA含量.结果 TIMP-3基因成功转入VSMCs中.术后4周,TIMP-3组的LVIDd、LVIDs、EDV和ESV值较正常鼠升高(P＜0.05),但小于VSMC(P ＜0.01)组和DMEM组(P＜0.01).RT-PCR结果显示:各移植组TIMP-3 mRNA含量均较对照组显著升高(P＜0.01),TIMP-3组较VSMC组、DMEM组明显增高(P＜0.01);TIMP-3组MMP-2 mRNA含量较VSMC组、DMEM组明显降低(P＜0.01).结论 将TIMP-3基因转染的VSMCs移植入心肌缺血区可明显抑制MMP-2的表达,进而抑制AMI后早期心肌重塑,改善心功能.