Autologous Cardiomyocytes from Masseter Muscles to Repair Myocardial Infarction (MI)

摘要 心肌梗死(MI)是由于缺乏足够的血液流向心脏而导致终末期死亡。 心肌细胞(CM)。心肌梗死及其相关并发症是全球主要的死亡原因。这个 寻找可以修复或取代丢失的CM的再生疗法仍然是一个令人生畏的挑战。这个 最重要的问题是难以获得可行的替代细胞。异源资源没有吸引力 因为有可能出现免疫排斥反应。从患者受损的心脏中采集祖细胞是 具有侵入性，并构成严重风险。对来自其他自体来源的体细胞进行重新编程可能导致 由于遗传或表观遗传障碍，产量非常低。然而，最近的一系列研究表明， 咬肌来源的祖细胞具有共同的来源和重叠的基因 心肌的表达模式。可从高度可及的咬肌中分离出基质金属蛋白酶 而我们的初步数据显示，在没有下颌运动障碍的情况下，基质金属蛋白酶的产率最高 与四肢肌祖细胞相比，肌层分化程度较高。重要的是，基质金属蛋白酶可以引起功能性 CM表型包括在特定条件下的心室、心房和起搏器CM。因此，基质金属蛋白酶 代表了一种理想的治疗方案，可最大限度地提高细胞后的心源性分化效率 移植，以便用自体CM重新填充梗塞的心脏区域。在 同时，基质金属蛋白酶避免了与免疫排斥、肿瘤形成和 回复到另一种表观遗传前体。目标1由体外研究组成，以分离和 确定基质金属蛋白酶(包括发育起源、表面标志和增殖潜能)的特征，以便 使用新的排序方法获得所需的CM种群。AIM 2旨在确定 MicroRNAs和转录因子网络调节小鼠血统承诺的机制 由miR-128调节的基质金属蛋白酶和基质金属蛋白酶的潜在心脏电位。最后，目标3侧重于 基质金属蛋白酶衍生细胞片植入对小鼠和猪心肌梗死心功能的影响 模特们。实验将检测基质金属蛋白酶在体内的细胞命运，并确定 这是缺血条件下细胞植入和功能整合的结果。这些研究将提供 在基础心脏发育生物学和细胞再生医学方面的新见解。这 该方法为新兴的个性化医疗领域带来了巨大的希望，并大力支持 从人咬肌中获取并体外扩增的自体基质金属蛋白酶可能会 作为CM的主要来源，对MI后患者的治疗将是非常有效的。

Abstract Myocardial infarction (MI) is caused by lack of adequate blood flow to the heart and results in terminal loss of cardiomyocytes (CM). MI and its related complications are a leading cause of death worldwide. The search for regenerative therapy that can repair or replace lost CM remains a daunting challenge. The foremost issue is the difficulty in procuring viable replacement cells. Heterologous sources are unattractive due to the potential for immunorejection. Harvesting progenitor cells from a patient's damaged heart is invasive and poses severe risks. Reprogramming somatic cells from other autologous sources can result in very low yields due to genetic or epigenetic barriers. A series of recent studies, however, has revealed that masseter muscle derived progenitor (MMP) cells share a common origin and have overlapping gene expression patterns with heart muscle. MMP can be isolated from highly accessible masseter muscles without mandible motor dysfunction and our preliminary data has shown that MMP yield the highest rate of CM differentiation as compared with limb muscle progenitors. Importantly, MMP can give rise to functional CM phenotypes including ventricular, atrial, and pacemaker CM under defined conditions. Therefore, MMP represent an ideal therapeutic candidate to maximize cardiogenic differentiation efficiency after cell transplantation in order to repopulate an infarcted heart region with a supply of autologous CM. At the same time, MMP avoid the common pitfalls associated with immunorejection, tumor formation, and reversion to an alternative epigenetic precursor. Aim 1 consists of in vitro studies to isolate and characterize MMP (including developmental origin, surface markers, and proliferation potential) in order to gain the desired CM population using novel sorting approaches. Aim 2 is designed to determine the mechanism by which microRNAs and transcription factor networks mediate the lineage commitments of MMP and the underlying cardiac potential of MMP as regulated by miR-128. Finally, Aim 3 focuses on the effects of implantation of MMP-derived cell sheets on the cardiac functions in mouse and porcine MI models. Experiments will examine the in vivo cell fate of MMP and determine any beneficial effects that result from cell engraftment and functional integration under ischemic conditions. These studies will provide new insights in both basic heart developmental biology and cell-based regenerative medicine. This approach holds great promise for the emerging field of personalized medicine and strongly supports the possibility that autologous MMP harvested from human masseter muscles and expanded in vitro will serve as a major source of CM that will be highly effective for treatment of patients after MI.