骨髓基质干细胞移植与心肌重建研究进展

骨髓基质干细胞是来源于骨髓的多能干细胞,在体、内外能分化成多种起源于中胚层的组织。其分化与其周围环境变化有关,可能需要一系列调控因子的参与。哺乳动物心肌从中胚层发育而来。在出生后早期,心肌细胞的增殖能力丧失,又没有相应的干细胞,损伤后心肌细胞不能再生。因而,心肌损伤后(如心肌梗死),常导致心肌细胞的不可逆性丢失和永久的功能丧失。植入外源性细胞是一个修复损伤心肌的、具有潜在临床应用价值的方法。骨髓基质干细胞在体、内外可诱导分化为肌源性细胞或心肌细胞。骨髓基质干细胞移植可以重建心肌,逆转左室重构,改善心功能,为心肌梗死提供一种新的治疗选择,有广阔的临床应用前景。     

骨髓基质干细胞移植与心肌重建研究进展

骨髓基质干细胞是来源于骨髓的多能干细胞，在体、内外能分化成多种起源于中胚层的组织。其分化与其周围环境变化有关，可能需要一系列调控因子的参与。哺乳动物心肌从中胚层发育而来。在出生后早期，心肌细胞的增殖能力丧失，又没有相应的干细胞，损伤后心肌细胞不能再生。因而，心肌损伤后(如心肌梗死)，常导致心肌细胞的不可逆性丢失和永久的功能丧失。植入外源性细胞是一个修复损伤心肌的、具有潜在临床应用价值的方法。骨髓基质干细胞在体、内外可诱导分化为肌源性细胞或心肌细胞。骨髓基质干细胞移植可以重建心肌，逆转左室重构，改善心功能，为心肌梗死提供一种新的治疗选择，有广阔的临床应用前景。     

心肌营养素1对谷氨酸诱导神经干细胞凋亡的作用

背景：心肌营养素1属于白细胞介素6细胞因子家族,近年发现其可能对中枢神经系统有重要保护作用。目的：探索重组腺病毒心肌营养素1对谷氨酸诱导神经干细胞凋亡的保护作用,为脑损伤提供新的治疗措施。方法：取新生Wistar大鼠海马神经干细胞,第2代培养第5天用于实验,神经干细胞分为3组：谷氨酸组、重组腺病毒心肌营养素1组及对照组,利用四唑蓝比色了解细胞存活情况及原位缺口末端标记技术检测细胞凋亡。结果与结论：谷氨酸组神经干细胞呈现明显形态改变,重组腺病毒心肌营养素1组未见类似改变,在谷氨酸暴露后12,24,48及72hMTT吸光度值均低于心肌营养素1组,而细胞凋亡率均高于心肌营养素1组。与其他两组比较,对照组相同时间点A值增高,细胞凋亡率降低。提示,心肌营养素1对谷氨酸损伤的神经干细胞具有保护作用,可以抑制神经干细胞凋亡,促进其存活和增殖。     

干细胞归巢与缺血心肌组织

由于缺血,特别是急性心肌梗死（AMI）造成的不可逆心肌坏死,导致心肌瘢痕形成,非缺血心肌的进行性心室重构,进一步加重心脏功能损伤。当今的治疗手段无法用具有正常功能的心肌细胞替代心肌瘢痕组织,而干细胞的研究进展为我们带来了一线光明。已经确认,在成人个体中仍存在具有自我复制更新和分化潜能的干细胞。     

心肌营养素1对谷氨酸诱导神经干细胞凋亡的作用

背景:心肌营养素1属于白细胞介素6细胞因子家族,近年发现其可能对中枢神经系统有重要保护作用。目的:探索重组腺病毒心肌营养素1对谷氨酸诱导神经干细胞凋亡的保护作用,为脑损伤提供新的治疗措施。方法:取新生Wistar大鼠海马神经干细胞,第2代培养第5天用于实验,神经干细胞分为3组:谷氨酸组、重组腺病毒心肌营养素1组及对照组,利用四唑蓝比色了解细胞存活情况及原位缺口末端标记技术检测细胞凋亡。结果与结论:谷氨酸组神经干细胞呈现明显形态改变,重组腺病毒心肌营养素1组未见类似改变,在谷氨酸暴露后12,24,48及72hMTT吸光度值均低于心肌营养素1组,而细胞凋亡率均高于心肌营养素1组。与其他两组比较,对照组相同时间点A值增高,细胞凋亡率降低。提示,心肌营养素1对谷氨酸损伤的神经干细胞具有保护作用,可以抑制神经干细胞凋亡,促进其存活和增殖。     

骨髓间充质干细胞与心肌再生的研究进展

心肌受损后，心肌细胞一般无法再生，可导致起搏、传导、或心肌舒缩功能受损。目前，随着对干细胞研究的深人，利用干细胞移植对受损心肌进行再生性治疗成为最有潜力治疗手段。骨髓问充质干细胞（MSCs）获取相对容易，不涉及道德伦理学及法律问题，在体外培养容易大量扩增而仍然保留“于细胞”特性，而成为修复损伤心肌的最佳种子细胞。本文将就目前MSCs对心肌再生治疗的研究进展进行综述。     

在心肌组织工程构建中的心肌干细胞：认识现状与预测未来

背景：长期以来,人们认为成年哺乳动物的心肌是终末分化的组织,没有再生能力。心肌细胞一旦受损将由纤维结缔组织取代。目的：重新认识心肌细胞,对心肌干细胞的相关研究做一综述,以明确心肌干细胞的存在。方法：计算机检索中国期刊网全文数据库以及PubMed数据库2003至2014年期间有关心肌干细胞的文章。检索词分别为“心肌干细胞,干细胞,心脏再生”和“cardiac stem cel s,stem cel s,cardiac regeneration ”。初检得到82篇文献,最终纳入文章40篇。结果与结论：心脏中存在具有再生潜能的心肌干细胞,现已研究出一些心肌干细胞的表面标记物。心肌干细胞的研究为临床治疗某些心肌细胞损伤性疾病开辟了崭新的思路,但心肌干细胞的数量较少,如何分离纯化、培养鉴定,并扩增为满足再生医学和组织工程需要的心肌细胞还有待于进一步研究,心肌干细胞的研究将为心肌组织工程研究开辟崭新的途径。     

诱导间充质干细胞向心肌样细胞的分化

背景:目前很多体内外实验都已表明间充质干细胞具有向心肌样细胞或心肌细胞分化的能力,这使间充质干细胞治疗心脏疾病成为可能。目的:比较诱导间充质干细胞向心肌样细胞分化实验方法的异同及存在的问题。方法:以"mesenchymal stem cells,cardiomyocyte,differentiation;间充质干细胞,心肌细胞,诱导;分化"为检索词,应用计算机检索2000-12/2010-12 PubMed数据库与万方数据库,与间充质干细胞诱导分化为心肌细胞相关的文章。结果与结论:间充质干细胞向心肌细胞分化的方法主要有:①心肌细胞条件培养液:间充质干细胞在体外经药物诱导或模拟体内心肌微环境能定向诱导分化为心肌样细胞。②与希望诱导成的目的细胞共同培养:间充质干细胞可经药物诱导诱导分化为心肌细胞,也可不经任何诱导在心肌微环境中分化为心肌细胞。虽然间充质干细胞在体外心脏病理条件下可分化为心肌细胞,使间充质干细胞治疗心脏疾病成为可能,但其研究有待进一步完善。     

骨髓间充质干细胞向心肌样细胞的诱导分化

骨髓间充质干细胞以其心肌横向分化的可塑性和多重优势,移植至缺血心肌中可分化为心肌细胞,增加有功能心肌细胞数量,在心肌损伤性疾病的治疗上展现着强大潜能,成为心肌再生的种子细胞之一,其向心肌样细胞的体外诱导分化是其中的一个研究热点。     

骨髓间充质干细胞经核转录因子κB途径干预心肌纤维化

背景:骨髓间充质干细胞移植能否直接干预心肌纤维化及其可能的机制尚不完全清楚。目的:观察骨髓间充质干细胞移植干预心肌纤维化的效果并分析其机制。方法:分离培养雄性小鼠骨髓间充质干细胞,经尾静脉输入异丙肾性心肌纤维化雌性小鼠为治疗组,另设未治疗组和正常对照组。5周后处死小鼠,实时荧光定量PCR检测心肌y染色体鉴别基因(SRY)、基质金属蛋白酶9、基质金属蛋白酶组织抑制剂1的表达;天狼猩红染色对比心脏胶原纤维含量;免疫组织化学染色法观察心脏核转录因子κB表达。结果与结论:骨髓间充质干细胞能归巢于纤维化心肌。与未治疗组相比,治疗组的心肌基质金属蛋白酶9、基质金属蛋白酶组织抑制剂1和核转录因子κB表达下调(P<0.05),胶原纤维含量下降(P<0.05)。结果表明,骨髓间充质干细胞移植干预心肌纤维化,其机制可能与抑制核转录因子κB过度活化有关。     

Robust Cardiac Regeneration: Fulfilling the Promise of Cardiac Cell Therapy

PurposeWe review the history of cardiac cell therapy, highlighting lessons learned from initial adult stem cell (ASC) clinical trials. We present pluripotent stem cell–derived cardiomyocytes (PSC-CMs) as a leading candidate for robust regeneration of infarcted myocardium but identify several issues that must be addressed before successful clinical translation.MethodsWe conducted an unstructured literature review of PubMed-listed articles, selecting the most comprehensive and relevant research articles, review articles, clinical trials, and basic or translation articles in the field of cardiac cell therapy. Articles were identified using the search terms adult stem cells, pluripotent stem cells, cardiac stem cell, and cardiac regeneration or from references of relevant articles, Articles were prioritized and selected based on their impact, originality, or potential clinical applicability.FindingsSince its inception, the ASC therapy field has been troubled by conflicting preclinical data, academic controversies, and inconsistent trial designs. These issues have damaged perceptions of cardiac cell therapy among investors, the academic community, health care professionals, and, importantly, patients. In hindsight, the key issue underpinning these problems was the inability of these cell types to differentiate directly into genuine cardiomyocytes, rendering them unable to replace damaged myocardium. Despite this, beneficial effects through indirect paracrine or immunomodulatory effects remain possible and continue to be investigated. However, in preclinical models, PSC-CMs have robustly remuscularized infarcted myocardium with functional, force-generating cardiomyocytes. Hence, PSC-CMs have now emerged as a leading candidate for cardiac regeneration, and unpublished reports of first-in-human delivery of these cells have recently surfaced. However, the cardiac cell therapy field's history should serve as a cautionary tale, and we identify several translational hurdles that still remain. Preclinical solutions to issues such as arrhythmogenicity, immunogenicity, and poor engraftment rates are needed, and next-generation clinical trials must draw on robust knowledge of mechanistic principles of the therapy.ImplicationsThe clinical transplantation of functional stem cell–derived heart tissue with seamless integration into native myocardium is a lofty goal. However, considerable advances have been made during the past 2 decades. Currently, PSC-CMs appear to be the best prospect to reach this goal, but several hurdles remain. The history of adult stem cell trials has taught us that shortcuts cannot be taken without dire consequences, and it is essential that progress not be hurried and that a worldwide, cross-disciplinary approach be used to ensure safe and effective clinical translation.     

Cellular cardiac regenerative therapy in which patients?

Cell-based myocardial regenerative therapy is undergoing experimental and clinical trials in order to limit the consequences of decreased contractile function and compliance of damaged ventricles owing to ischemic and nonischemic myocardial diseases. A variety of myogenic and angiogenic cell types have been proposed, such as skeletal myoblasts, mononuclear and mesenchymal bone marrow cells, circulating blood-derived progenitors, adipose-derived stromal cells, induced pluripotent stem cells, umbilical cord cells, endometrial mesenchymal stem cells, adult testis pluripotent stem cells and embryonic cells. Current indications for stem cell therapy concern patients who have had a left- or right-ventricular infarction or idiopathic dilated cardiomyopathies. Other indications and potential applications include patients with diabetic cardiomyopathy, Chagas heart disease (American trypanosomiasis), ischemic mitral regurgitation, left ventricular noncompacted myocardium and pediatric cardiomyopathy. Suitable sources of cells for cardiac implant will depend on the types of diseases to be treated. For acute myocardial infarction, a cell that reduces myocardial necrosis and augments vascular blood flow will be desirable. For heart failure, cells that replace or promote myogenesis, reverse apoptopic mechanisms and reactivate dormant cell processes will be useful. It is important to note that stem cells are not an alternative to heart transplantation; selected patients should be in an early stage of heart failure as the goal of this regenerative approach is to avoid or delay organ transplantation. Since the cell niche provides crucial support needed for stem cell maintenance, the most interesting and realistic perspectives include the association of intramyocardial cell transplantation with tissue-engineered scaffolds and multisite cardiac pacing in order to transform a passive regenerative approach into a ‘dynamic cellular support’, a promising method for the creation of ‘bioartificial myocardium’.     

基因修饰干细胞治疗心肌梗死：临床前和临床应用中的相关问题

背景：干细胞具有分化为心肌及血管的潜力,可使缺血部位心肌得以组织修复及血运重建。该特性使干细胞移植成为具有发展前景的治疗缺血性心脏病的新型疗法。但干细胞移植后的长期存活以及远期疗效问题仍是难题。基因修饰联合干细胞移植的出现为干细胞研究提供了新思路。目的：就现阶段用于心脏再生治疗的干细胞种类、治疗性基因的选择、移植载体与移植途径的探索及基因修饰干细胞在心血管治疗领域的临床应用进行概述。方法：应用计算机检索PubMed数据库中2006年1月至2013年12月关于干细胞的文章,在标题和摘要中以＂stem cells;genetic therapy;myocardial infarction;regenerative medicine;tissue construction＂为检索词进行检索。选择文章内容与干细胞有关者,同一领域文献则选择近期发表或发表在权威杂志文章。最终选择40篇文献进行综述。结果与结论：干细胞联合基因修饰疗法可显著增强移植后的疗效,骨髓间充质干细胞是目前应用最广泛的种子细胞之一,通过腺病毒及腺相关病毒介导的抗凋亡、促血管生成、抗炎症等基因修饰后的干细胞疗效将显著提高。基因修饰干细胞移植有潜力应用于包括心肌梗死在内的多种临床疾病,但其长期安全性仍有待进一步研究。     

心肌梗死的干细胞治疗

目的:认识国内外在干细胞移植治疗心肌梗死方面的研究现状。资料来源:检索Medline数据库1998-01/2005-12有关干细胞移植治疗心肌梗死的文章,检索词为"stem cells,myocardial infarction,celltransplantation",限定语言种类为英语。资料选择:对资料进行初筛,选择与干细胞移植治疗心肌梗死相关的文章,去除重复性研究和综述类文章。资料提炼:共收集到相关文章106篇,最终纳入30篇,去除76篇。资料综合:心肌梗死是由于冠状动脉闭塞导致心脏血流供应中断而形成的以心肌细胞坏死为特征的疾病。细胞心肌成形术是在干细胞研究的基础上应运而生的,通过干细胞移植促进心肌细胞再生,防止心室重构和改善心脏功能。目前国内外已尝试应用多种类型的干细胞移植治疗心肌梗死,包括骨骼肌卫星细胞、胚胎干细胞和骨髓干细胞等。虽然还有许多尚待解决的问题,但是动物实验乃至临床研究结果都展现了干细胞移植治疗心肌梗死的广阔前景。结论:干细胞移植为治疗心肌梗死提供了一种很有潜力的新手段,但要真正用于临床还需要解决一些应用中的关键问题。     

SDF-1α as a therapeutic stem cell homing factor in myocardial infarction

Myocardial infarction is associated with persistent muscle damage, scar formation and depressed cardiac performance. Recent studies have demonstrated the clinical significance of stem cell-based therapies after myocardial infarction with the aim to improve cardiac remodeling and function by inducing the reconstitution of functional myocardium and formation of new blood vessels. Stem cell homing signals play an important role in stem cell mobilization from the bone marrow to the ischemic cardiac environment and are therefore crucial for myocardial repair. To date, the most prominent stem cell homing factor is the chemokine SDF-1α/CXCL12. This protein was shown to be significantly upregulated in many experimental models of myocardial infarction and in patients suffering from ischemic cardiac diseases, suggesting the involvement in the pathophysiology of these disorders. A number of studies focused on manipulating SDF-1α and its receptor CXCR4 as central regulators of the stem cell mobilization process. Targeted expression of SDF-1α after myocardial infarction was shown to result in increased engraftment of bone marrow-derived stem cells into infarcted myocardium. This was accompanied by beneficial effects on cardiomyocyte survival, neovascularization and cardiac function. Thus, the SDF-1/CXCR4 axis seems to be a promising novel therapeutic approach to improve post-infarction therapy by attracting circulating stem cells to remain, survive and possibly differentiate in the infarct area. This review will summarize clinical trials of stem cell therapy in patients with myocardial infarction. We further discuss the basic findings about SDF-1α in stem cell recruitment and its therapeutic implications in experimental myocardial infarction.     

The potential of embryonic stem cells to treat heart disease

Cell therapy is currently receiving growing interest as a new means of repairing infarcted myocardium. Despite the encouraging experimental results yielded by autologous skeletal myoblasts and bone marrow-derived hematopoietic and mesenchymal stem cells, there is increasing evidence that the plasticity of these adult cells is more limited than initially thought and that, consequently, their conversion into cardiomyocytes is unlikely or, at best, quantitatively very limited. As the engrafted cells should electromechanically interact with host cardiac cells to form a functional syncytium, attention is now increasingly focused on cells that feature a true cardiomyogenic differentiation potential, enabling them to connect with the neighboring cardiomyocytes. In this setting, embryonic stem cells are particularly attractive, since they can be precommitted towards a cardiac lineage and complete their full maturation in vivo, possibly under the influence of host tissue-associated paracrine signaling pathways. Although a potential clinical use of embryonic stem cells is still fraught with difficulty (amplification, purification and immunogenicity), available experimental data suggest a consistent efficacy in repairing infarcted myocardium, which has stimulated efforts to address these issues.     

Cardiac cell therapy: a treatment option for cardiomyopathy

Cardiomyopathy is a common clinical disorder affecting the heart muscle. This disease process frequently leads to congestive heart failure and will often progress to end-stage heart failure. Present standard of care treatment options for cardiomyopathy include medical management, lifestyle changes, and surgical procedures including left ventricular assist devices as a destiny therapy or bridging to heart transplantation. Even despite advances in drug therapy, mechanical assist devices, and organ transplantation, more than half of the persons with cardiomyopathy will die within 5 years of diagnosis. Small uncontrolled clinical trials have demonstrated cardiac stem cells as a treatment option for cardiomyopathy. The theory for the individual or combined mechanism of action for stem cells includes (1) transdifferentiation to blood vessels or myocardium, (2) fusion with the native dysfunctional myocytes to augment function, and (3) homing that may be a systemic or panacrine response for recruiting other cells, and growth factors to help improve oxygen delivery and myocardial function. The field of cardiac cell therapy is rapidly progressing to gather more data with intermediate-size, double-blinded trials that will demonstrate the safety and efficacy of cell therapy.     

Cellular mechanisms underlying cardiac engraftment of stem cells

Introduction: Over the past decade, it has become clear that long-term engraftment of any ex vivo expanded cell product transplanted into injured myocardium is modest and all therapeutic regeneration is mediated by stimulation of endogenous repair rather than differentiation of transplanted cells into working myocardium. Given that increasing the retention of transplanted cells boosts myocardial function, focus on the fundamental mechanisms limiting retention and survival of transplanted cells may enable strategies to help to restore normal cardiac function.

Areas covered: This review outlines the challenges confronting cardiac engraftment of ex vivo expanded cells and explores means of enhancing cell-mediated repair of injured myocardium.

Expert opinion: Stem cell therapy has already come a long way in terms of regenerating damaged hearts though the poor retention of transplanted cells limits the full potential of truly cardiotrophic cell products. Multifaceted strategies directed towards fundamental mechanisms limiting the long-term survival of transplanted cells will be needed to enhance transplanted cell retention and cell-mediated repair of damaged myocardium for cardiac cell therapy to reach its full potential.     

干细胞移植对心肌电活动的影响

背景:离子通道是心肌细胞最重要的电生理特性之一,干细胞向心肌细胞分化过程中离子通道的变化情况,以及干细胞移植到心脏后对心肌组织电生理学特性的影响是心血管疾病研究的新热点。目的:综述干细胞移植对心肌电活动影响的现状及新进展。方法:应用计算机检索维普、PubMed及SpringerLink数据库中2000-01/2011-05关于干细胞移植对心肌电活动影响的文章,在标题和摘要中以"骨髓间充质干细胞、胚胎干细胞、诱导多能干细胞、心肌电活动、离子通道"或"Bone marrow mesenchymal stem cells、Embryonic stem cells、Induced pluripotent stem cells、Cardiac electrical activity、Ion channels"为检索词进行检索。结果与结论:最终选择21篇文献进行分析。目前国内外临床实验均未观察到干细胞移植产生的致命性心律失常,但一些心电活动和离子通道动力学在移植后发生改变,因此干细胞移植对心肌电生理的影响不容小觑。诱导多能干细胞不仅能够分化为心肌细胞,而且具有与心肌类似的电生理活动,在受损心肌进行再生性治疗中必将得到更加广泛的研究及应用。     

High-resolution X-ray microtomography for three-dimensional imaging of cardiac progenitor cell homing in infarcted rat hearts

The recent introduction of stem cells in cardiology provides new tools in understanding the regenerative processes of the normal and pathological heart and has opened a search for new therapeutic strategies. Recent published reports have contributed to identifying possible cellular therapy approaches to generate new myocardium, involving transcoronary and intramyocardial injection of progenitor cells. However, one of the limiting factors in the overall interpretation of clinical results obtained by cell therapy is represented by the lack of three-dimensional (3D) high-resolution methods for the visualization of the injected cells and their fate within the myocardium. This work shows that X-ray computed microtomography may offer the unique possibility of detecting, with high definition and resolution and in ex vivo conditions, the 3D spatial distribution of rat cardiac progenitor cells, labelled with iron oxide nanoparticles, inside the infarcted rat heart early after injection. The obtained 3D images represent a very innovative progress as compared to experimental two-dimensional (2D) histological analysis, which requires time-consuming energies for image reconstruction in order to provide the overall distribution of rat clonogenic cells within the heart. Through microtomography, we were able to observe in 3D the presence of these cells within damaged cardiac tissue, with important structural details that are difficult to visualize by conventional bidimensional imaging techniques. This new 3D-imaging approach appears to be an important way to investigate the cellular events involved in cardiac regeneration and represents a promising tool for future clinical applications.