骨骼肌卫星细胞移植治疗心肌梗死的研究进展

成熟的心肌细胞虽然不是终末分化细胞,但也只有有限的分裂、增殖能力[1],因此心肌梗死(M I)后,心肌不能完全修复而留下坏死区,坏死心肌逐渐被纤维疤痕所替代,具有收缩功能的心肌细胞减少,周围心肌的工作负荷将随之发生改变,产生不同程度的结构和功能异常,导致相当一部分患者在远期发生充血性心力衰竭,并成为致死的主要原因。现在用于M I治疗的方法通常只能改善心肌供血,不能使坏死心肌复生,心脏移植虽可替代受损心脏,但经常受到一些特定条件的限制而难以广泛推广应用。近年来,随着分子生物学的发展,用正常的肌细胞取代疤痕组织,增加梗死部…     

骨骼肌卫星细胞移植到大鼠体内生长发育的初步研究

目的探讨胶体金标记方法的可行性以及卫星细胞移植到正常大鼠左心室心肌后的生长分化情况.方法将胶体金标记的骨骼肌卫星细胞移植到正常大鼠心肌中,用免疫组化、共聚焦免疫荧光双标染色及透射电镜多种方法观察卫星细胞的增殖分化情况.结果移植细胞可以在宿主心肌中生长分化.在移植后1月,有多核的肌管和骨骼肌纤维形成,但移植细胞与心肌细胞之间未见连接.结论胶体金标记方法适用于光镜、电镜研究.卫星细胞移植到正常大鼠左心室心肌后能够增殖分化为骨骼肌纤维,但没有与宿主心肌产生连接.     

bFGF基因修饰骨骼肌卫星细胞移植对心肌梗死兔心功能的影响

目的:观察bFGF基因修饰骨骼肌卫星细胞在心肌梗死区存活情况以及对心功能的影响。方法:分离培养兔骨骼肌卫星细胞,构建bFGF基因修饰骨骼肌卫星细胞。建立急性心肌梗死兔模型,随机分为骨骼肌卫星细胞组、bFGF基因修饰骨骼肌卫星细胞组和对照组,每组6只,在各组动物梗死心肌内分别注射骨骼肌卫星细胞、bFGF基因修饰骨骼肌卫星细胞及等量的细胞培养液。造模前及细胞移植4周后,心脏超声测定兔左室舒张末期内径(LVEDD)、左室收缩末期内径(LVESD)、短轴缩短率(FS)和射血分数(EF),观察移植4周后心脏病理切片中心肌梗死边缘区骨骼肌卫星细胞存活情况、bFGF表达情况及新生血管形成情况。结果:细胞移植4周后病理学检查提示骨骼肌卫星细胞在心肌梗死边缘区存活,bFGF基因修饰骨骼肌卫星细胞组可见大量EGFPbFGF融合蛋白表达。与对照组相比,骨骼肌卫星细胞组和bFGF基因修饰骨骼肌卫星细胞组心肌梗死边缘区微血管密度均有增加(78.3±5.2和98.5±8.6对25.2±4.6,P均0.05),且bFGF基因修饰骨骼肌卫星细胞组微血管密度较骨骼肌卫星细胞组明显增加(P0.05)。与造模前相比,移植4周后对照组和骨骼肌卫星细胞组均出现LVESD和LVEDD增大,FS和EF降低(P均0.05),bFGF基因修饰骨骼肌卫星细胞组各指标与造模前相比差异无统计学意义。移植4周后,骨骼肌卫星细胞组和bFGF基因修饰骨骼肌卫星细胞组LVESD及LVEDD均小于对照组,FS和EF均高于对照组(P均0.05);与骨骼肌卫星细胞组相比,bFGF基因修饰骨骼肌卫星细胞组LVESD及LVEDD减小,FS和EF升高(P均0.05)。结论:bFGF基因修饰骨骼肌卫星细胞自体移植可增加急性心肌梗死兔心肌梗死边缘区新生血管形成,改善心功能。     

骨骼肌卫星细胞移植后心肌梗死区血管内皮因子表达及血管新生作用

目的:研究骨骼肌卫星细胞移植后心肌梗死(MI)区血管内皮因子(VEGF)表达及血管新生作用。方法:成年Louis近交系大鼠,结扎前降支建立急性MI模型,将骨骼肌卫星细胞移植到梗死区,2W后应用免疫组化方法鉴定梗死区VEGF的表达及新生血管密度。结果:骨骼肌卫星细胞在梗死区增殖、分化良好,梗死区VEGF表达移植组明显高于对照组(P<0.05),新生血管密度移植组也高于对照组(P<0.05)。结论:移植区卫星细胞可以分泌生长因子,促进血管形成,改善梗死区细胞的生存环境。     

小鼠成体骨骼肌卫星细胞提取及纯化方法的改进

目的建立一种快速高效的小鼠成体骨骼肌卫星细胞的提取、纯化的实验方法。方法通过布比卡因预处理激活肌卫星细胞,48小时后,以混合酶一步消化法及改良纯化法从成年骨骼肌中分离高纯度卫星细胞,并与普通差速贴壁法、反复差速贴壁法及Percoll非连续密度梯度离心法等纯化方法相比较。结果通过改良提取、纯化法所得到的骨骼肌卫星细胞纯度可达到(82.53±3.16)%,明显高于普通差速贴壁法、反复差速贴壁法及Percoll非连续密度梯度离心法(P<0.05),并具有很好的增殖及分化能力。结论通过采用改良成体骨骼肌卫星细胞提取及纯化法,能快速高效地获取高纯度肌卫星细胞。     

细胞移植治疗心肌梗死的研究进展

急性心肌梗死 (ＡＭＩ)作为冠心病中最危重的临床类型 ,是造成冠心病患者死亡的主要原因。近年来随着介入治疗、冠状动脉 (冠脉 )旁路移植术等在临床的应用 ,ＡＭＩ的急性期病死率有了一定程度的下降 ,但患者最终死于心力衰竭的远期病死率并未下降。其原因在于心肌梗死 (ＭＩ)后残留的心肌由于代偿而肥厚 ,引起心室重构 ,进而促使心力衰竭发生 ,最终造成患者死亡。故此 ,如何促进梗死区内心肌细胞再生 ,提高心肌细胞数目 ,防止心室重构 ,是防止ＭＩ后心力衰竭发生及降低ＭＩ后远期病死率的关键。用细胞移植替代治疗 ,有可能从根本上解决这一…     

骨骼肌卫星细胞在组织工程与运动损伤修复中的应用

<正>从骨骼肌的发生上看,骨骼肌纤维是一种终末分化的细胞类型,由胚胎的生肌节和各处的间充质细胞分化而成〔1〕。而成熟的骨骼肌细胞属于一种有丝分裂后细胞,不能进行有丝分裂。在成年动物骨骼肌纤维与基膜之间,有一种体积较小的扁平或立方形细胞,排列在肌纤维表面,称为肌卫星细胞(MSC)。MSC是具有增殖和自我更新能力的成肌前体细胞或单能成肌干细胞,自被发现以来,这种组织特异的祖细胞在组织工程、基因治疗、运动医学等领域展示了良好的应用前景。本文围绕MSC在组织工程与运动创伤修复中的应用作一综述。     

细胞移植治疗心肌梗死后心力衰竭的研究进展

溶栓和急诊经皮经腔冠状动脉血管成形术 (ＰＴＣＡ)等血运重建技术 ,可以使急性心肌梗死的梗死区早期再灌注 ,减少梗死面积 ,保护心功能 ,提高患者的生存率 ,但是却不能逆转已经坏死的心肌。成体心肌细胞是分化完全的细胞 ,缺乏再生能力 ,坏死后由无收缩能力的纤维组织填充 ,梗死区扩张、变薄 (即延展 ) ,非梗死区则出现离心性肥厚 ,心脏发生重构 ,心腔扩大 ,最终导致心力衰竭。尽管血管紧张素转换酶抑制剂及 β 受体阻滞剂等药物使心力衰竭患者的预后得以改善 ,但是并不能改变心肌细胞数量减少这一心力衰竭的根本原因。因此 ,心力衰竭已成…     

衰老个体骨骼肌卫星细胞的研究进展

<正>骨骼肌是由单核成肌细胞融合而成的多核肌纤维组成,肌纤维组织通过收缩产生力量和运动。骨骼肌中含有大量处于静息状态的肌源性干细胞(MDSCs),位于肌纤维质膜和基底膜之间,被称为卫星细胞,这些细胞对于骨骼肌的再生能力至关重要^[1]。一旦机体发生损伤,卫星细胞就会停止静息状态,开始增殖,并产生大量肌源性祖细胞,这些祖细胞进一步参与肌源性活动,生成新的肌纤维并取代受损的组织^[2]。肌纤维的生长、稳态和修复都依赖于卫星细胞,     

骨骼肌成肌细胞移植治疗急性心肌梗死的研究进展

骨骼肌成肌细胞具有来源广泛、易于获得,自体移植不受供体来源限制,增殖能力及抗缺血、缺氧能力强大,易在梗死区内存活等多种优点,是干细胞治疗的重要来源。该文主要阐述骨骼肌成肌细胞移植治疗急性心肌梗死的研究进展。     

成年犬自体骨骼肌成肌细胞移植于急性心肌梗死区的实验研究

目的观察心肌内和冠状动脉内注射法移植自体骨骼肌成肌细胞于急性心肌梗死区的生长分化特点。方法以改良成年犬骨骼肌成肌细胞培养方法进行细胞分离及扩增。结扎冠状动脉前降支中段,建立急性心肌梗死模型。分为直接注射对照、移植,冠状动脉内注射对照、移植4组,每组5只。不开通冠状动脉,分别向梗死心肌内和梗死相关冠状动脉内注射自体骨骼肌成肌细胞(1·0~1·4×108个)或等量生理盐水。移植4周后通过HE染色、PTH染色、骨骼肌特异性慢肌球蛋白抗体免疫组化染色和透射电镜寻找梗死区内存在新生肌组织的证据并观察其生长特点。结果经心肌内直接注射和冠状动脉内注射移植自体骨骼肌成肌细胞4周后,透射电镜及HE染色下均可在梗死区内找到新生幼稚肌原性细胞存在,PTH染色证实有新生的横纹肌组织形成,骨骼肌特异性慢肌球蛋白抗体免疫组化染色发现有骨骼肌原性的成熟肌组织存在;成肌细胞直接注射组内新生的肌组织排列较为密集,而冠状动脉内成肌细胞注射组内的新生肌组织排列较分散。结论通过心肌内直接注射和经梗死相关冠状动脉注射将自体骨骼肌成肌细胞移植到急性心肌梗死区后均能形成成熟的肌组织,为以骨骼肌成肌细胞进行急性心肌梗死的细胞心肌成形治疗提供了组织学依据。     

Autologous intramyocardial injection of cultured skeletal muscle-derived stem cells in patients with non-acute myocardial infarction.

AIM: Experimental animal studies suggest that the use of skeletal myoblast in patients with myocardial infarction may result in improved cardiac function. The aim of the study was to assess the feasibility and safety of this therapy in patients with myocardial infarction. METHODS AND RESULTS: Twelve patients with old myocardial infarction and ischaemic coronary artery disease underwent treatment with coronary artery bypass surgery and intramyocardial injection of autologous skeletal myoblasts obtained from a muscle biopsy of vastus lateralis and cultured with autologous serum for 3 weeks. Global and regional cardiac function was assessed by 2D and ABD echocardiogram. 18F-FDG and 13N-ammonia PET studies were used to determine perfusion and viability. Left ventricular ejection fraction (LVEF) improved from 35.5+/-2.3% before surgery to 53.5+/-4.98% at 3 months (P=0.002). Echocardiography revealed a marked improvement in regional contractility in those cardiac segments treated with skeletal myoblast (wall motion score index 2.64+/-0.13 at baseline vs 1.64+/-0.16 at 3 months P=0.0001). Quantitative 18F-FDG PET studies showed a significant (P=0.012) increased in cardiac viability in the infarct zone 3 months after surgery. No statistically significant differences were found in 13N-ammonia PET studies. Skeletal myoblast implant was not associated with an increase in adverse events. No cardiac arrhythmias were detected during early follow-up. CONCLUSIONS: In patients with old myocardial infarction, treatment with skeletal myoblast in conjunction with coronary artery bypass is safe and feasible and is associated with an increased global and regional left ventricular function,improvement in the viability of cardiac tissue in the infarct area and no induction of arrhythmias.     

Skeletal myoblasts and cardiac repair

The seminal experiments showing that cells transplanted in infarcted hearts could effect myocardial tissue repair have provided the proof of concept that cell therapy might be an effective means of improving the outcome of patients with severe heart failure. Because of their appealing characteristics (autologous origin, in vitro scalability, high resistance to ischemia), skeletal myoblasts have undergone extensive preclinical testing that has consistently demonstrated their ability to preserve postinfarct left ventricular function and to limit remodelling. As this functional efficacy occurs despite a poor long-term engraftment rate and the inability of myoblasts to convert into cardiomyocytes, the hypothesis has been raised that the predominant mechanism of action could involve paracrine signalling rather than a direct contractile effect of the graft. These preclinical data have paved the way for the early human trials which have confirmed the feasibility and safety of this approach. The mixed results in terms of efficacy should not be discouraging; they only reflect that the field is still in infancy and have yet been helpful in identifying some key issues like the limited efficiency of current cell transfer techniques and the high rate of early posttransplantation cell death. It is clear, however, that myoblasts and, more generally, adult stem cells cannot truly repair infarcted myocardium through the generation of new cardiomyocytes. This first wave of clinical studies thus delineates the research pathways that need to be followed for overcoming these hurdles and consequently allow myoblast transplantation to become a potentially effective adjunct to current heart failure therapies.     

低氧诱导因子-1α基因修饰后的成肌细胞移植治疗心肌梗死的研究

目的评价低氧诱导因子-1α(HIF-1α)基因修饰骨骼肌成肌细胞(SkMs)治疗心肌梗死的可行性及其疗效。方法将71只Wister大鼠采用结扎冠状动脉左前降支制备心肌梗死模型,通过局部注射法将细胞植入心肌梗死区域。其中将制膜成功的42只成活大鼠随机分为假手术组(SO组,6只)、注射培养液组(DMEM组,6只)、移植SkMs组(SkMs组,10只)、移植感染了携带HIF-1α空载体腺病毒的SkMs组(Ad/GFP组,10只)和移植感染了携带HIF-1α基因腺病毒的SkMs组(Ad/HIF-1α组,10只)。术后28天用免疫组织化学法和血流动力学评价治疗效果。结果28天后SkMs组、Ad/GFP组和Ad/HIF-1α组大鼠梗死心肌周围血管新生明显,以Ad/HIF-1α组最为显著(P<0.05),且胶原沉积最少;SkMs组、Ad/GFP组和Ad/HIF-1α组大鼠左心室收缩功能好转,Ad/HIF-1α组最为显著(P<0.05)。结论HIF-1α基因修饰后的SkMs移植较单纯成肌细胞移植是治疗心肌缺血更为有效的方法。     

自体骨骼肌成肌细胞移植对心肌梗死兔心室重构和血管新生的影响

目的观察经冠状动脉途径移植自体骨骼肌成肌细胞(SMs)对急性心肌梗死兔心室重构和血管新生的影响。方法取日本大耳白兔45只,随机分为3组:经冠状动脉注射SMs移植组(移植组)、对照组和假手术组,每组15只。术后4周,检测各组免左心室质量及左心室质量指数,并以免疫组织化学法和ELISA法分别检测各组兔新生血管数目和血管内皮生长因子(VEGF)浓度。结果术后4周,与假手术组比较,移植组和对照组左心室质量及左心室质量指数明显增加(P0.01);与对照组比较,移植组左心室质量及左心室质量指数明显降低(P0.01)。与假手术组比较,对照组和移植组新生血管数目、梗死心肌组织中VEGF浓度明显增多,而移植组较对照组增多更明显(P0.05,P0.01)。结论经冠状动脉途径自体SMs移植可增加VEGF表达,诱导血管新生,改善心肌梗死后心室重构。     

急性前壁心肌梗死心电图ΣR、ΣQ、ΣST演变特点

目的　探讨急性前壁心肌梗死Q波、R波及ST段演变规律。方法　采用单极胸导联心电图在胸部进行体表标测 ,分别计算∑R、∑Q、∑ST。结果　∑R在胸痛发作后 12h内下降速度最快 ,12h后下降速度较慢 ,两者比较差异有非常显著性 (P <0 .0 1) ;∑Q在 2 4h内与 2 4h后形成对比差异有非常显著性 (P <0 .0 1) ;∑ST在 2 4h内下降速度比 2 4h后下降速度显著增快 ,两者比较差异有显著性 (P <0 .0 5 )。结论　观察心肌梗死急性期心电图∑R、∑Q、∑ST演变规律 ,以便采取急救措施 ,及时挽救濒死心肌。     

Benefit of stem cells and skeletal myoblast cells in dilated cardiomyopathies

Although some authors suggest that there is mitotic division in the heart,most cardiomyocytes do not have the capacity to regenerate after myocardial infarction and when this occurs there is a deterioration of contractile function,and if the area of infarction is extensive ventricular remodeling may occur,leading to the development of heart failure.Cell transplantation into the myocardium with the goal of recovery of cardiac function has been extensively studied in recent years. The effects of cell therapy are based directly on the cell type used and the type of cardiac pathology.For myocardial ischemia in the hibernating myocardium, bone marrow cells have functional benefits,however these results in transmural fibrosis are not evident. In these cases there is a benefit of implantation with skeletal myoblasts,for treating the underlying cause of disease,the loss of cell contractility.     

经冠状动脉注射法移植成年犬自体骨骼肌成肌细胞于急性心肌梗死区的病理研究

目的观察冠状动脉内注射法移植自体骨骼肌成肌细胞到无再灌注急性心肌梗死区后的生长分化特点。方法结扎犬冠状动脉前降支中段,建立急性心肌梗死模型;杂种成年犬10只,分为对照组和经冠状动脉注射移植组,各5只。经梗死相关冠状动脉内注射自体骨骼肌成肌细胞悬液10 ml(1.0~1.4×108个)或等量生理盐水;4周后通过HE染色、PTH染色、骨骼肌特异性慢肌球蛋白抗体免疫组织化学染色和透射电镜评价移植细胞病理转归。结果经冠状动脉内注射移植自体骨骼肌成肌细胞4周后,透射电镜及HE染色下可在梗死区内找到新生幼稚肌源性细胞存在,PTH染色证实有新生的横纹肌组织形成,骨骼肌特异性慢肌球蛋白抗体免疫组织化学染色发现有骨骼肌源性的成熟肌组织存在且新生肌组织排列较分散。结论通过经梗死相关冠状动脉注射将自体骨骼肌成肌细胞移植到急性心肌梗死区后能形成成熟的肌组织。     

Skeletal myoblast transplantation through a catheter-based coronary sinus approach: an effective means of improving function of infarcted myocardium.

AIMS: This study was designed to assess the functional effects of a transvenous coronary sinus technique of skeletal myoblast delivery in infarcted myocardium. METHODS AND RESULTS: An anterior myocardial infarction was created percutaneously in 14 sheep. Simultaneously, a muscle biopsy was harvested and expanded. Two weeks later, sheep were instrumented percutaneously with a dedicated catheter incorporating an extendable needle for puncture of the venous wall and, under endovascular ultrasound guidance, a microcatheter was advanced through the needle into the target scar for cell delivery. Following the baseline echocardiographic assessment of left ventricular (LV) function, sheep were randomly allocated to receive four-staged in-scar injections of either autologous cells (n=7) or culture medium (n=7). Two months later, LV function was reassessed blindly and hearts were explanted for subsequent histological and immunohistochemical analysis. There were no acute procedural complications. Baseline LV ejection fraction (EF) was significantly lower in transplanted sheep than in controls [38% (35-48) vs. 51% (38-55), respectively, P=0.03; median (range)]. Two months later, LVEF was significantly higher in the transplanted group than in controls [50% (47-56) vs. 39% (36-47), respectively, P=0.002]. Clusters of myoblasts were identified by histology and immunohistochemistry in three of the seven transplanted sheep. CONCLUSION: These data suggest the functional efficacy of the transvenous coronary sinus technique as a less invasive means of cell delivery to infarcted myocardium.