Bioenergetics in Hypertrophied and Remodeled Left Ventricle

描述（由申请人提供）：已知左心室壁（ENDO）的内层对氧化应激最敏感。我们假设存在通过肌酸激酶（CK）和ATP酶的ATP生成率储备的跨壁梯度，这在ENDO中是最低的，导致LVH心脏的ENDO脆弱性。尽管对心肌修复的细胞疗法非常感兴趣，但迄今为止的大多数研究报告都旨在修复或预防继发于冠状动脉疾病的心肌梗死心脏的LV功能障碍。鉴于心脏移植患者中有超过50%的病因是非缺血性CHF，在进行大规模临床试验之前，迫切需要使用非缺血性大型动物模型进行研究。细胞疗法的有益作用的机制尚未明确。这是一个一致的发现，植活率低。然而，一致地观察到受体心脏的LV收缩功能的长期改善。因此，除了移植细胞的心肌再生外，左室功能的改善也可能与受体心肌蛋白差异表达的变化有关。比较两种继发于压力超负荷或梗死后LV重构的LVH猪模型，将每两周测量MSC移植对LV收缩功能（MRI）、心肌灌注、心肌氧合水平（1H-MRS）和ATP周转率（31 P-MRS）的影响，持续8周，将通过比较蛋白质组学检查受体心肌差异蛋白表达。具体目标是：SA 1。采用新近发展的T1-nom P-31磁化饱和度转移（MST）方法，检测左室肥厚心脏ENDO时心肌ATP转换率是否通过CK和ATP酶发生最严重的改变，以及其严重程度是否与左室功能障碍的严重程度呈线性相关。SA 2.研究同种异体MSC移植的功能性有益作用是否伴随着伴有或不伴有缺血性冠状动脉疾病的LVH心脏的ENDO中通过CK和ATP酶的ATP产生能力的改善，以及这些功能性有益作用是否伴随着来自移植的MSC以及内源性CPC的心肌再生。SA3：研究细胞治疗的功能性有益作用是否与受体心肌的差异蛋白表达谱有关。我们将采用先进的液相色谱-质谱法为基础的比较蛋白质组学方法来定量确定蛋白质表达的变化，特别强调生长因子家族蛋白质和参与能量代谢的蛋白质。实验结果将首次阐明在体LVH心脏中ATP周转率通过CK和ATP酶的跨壁梯度。这些研究结果将促进我们对细胞治疗心肌修复机制的理解，并为CHF患者提供更好的诊断和治疗方式。

DESCRIPTION (provided by applicant): The inner layers of the left ventricular wall (ENDO) are known to be the most susceptible to oxidative stresses. We hypothesize that there is transmural gradient of reserves of ATP production rate via both creatine kinase (CK) and ATPase, which is the lowest in ENDO that results in the ENDO vulnerability in LVH hearts. Despite the intense interest in cellular therapy for myocardial repair, the majority of research reports to date have been designed to repair or prevent LV dysfunction in hearts with myocardial infarction secondary to coronary arteries diseases. Given the fact that more than 50% of heart transplant CHF patients whose etiology is nonischemic, studies using nonischemic large animal model is urgently needed before pursuing large scale clinical trials. The mechanisms underlying the beneficial effects of cellular therapy are not well defined. It is a consistent finding that the engraftment rate is low. However, the long term improvement of the LV contractile function of the recipient heart is consistently observed. Therefore, in addition to the myocardial regeneration from the engrafted cells the improved LV chamber function is also likely related to the changes of the recipient myocardial protein deferential expression. Comparing two swine models of LVH secondary to pressure overload or to postinfarction LV remodeling, the effects of MSCs transplantation on LV contractile function (MRI); myocardial perfusion, myocardial oxygenation level (1H-MRS); and ATP turnover rate (31P- MRS) will be measured biweekly for 8 weeks, the recipient myocardial differential protein expression will be examined by comparative proteomics. The specific aims are: SA1. Using the recently developed T1-nom P-31 magnetization saturation transfer (MST) methods to examine whether the myocardial ATP turnover rate via CK and ATPase are most severely altered in the ENDO of LVH hearts, and whether the severity of which is linearly related to the severity of the LV dysfunction. SA2. To examine whether the functional beneficial effects of allogenic MSC transplantation are accompanied by the improvement of ATP production capacity via CK and ATPase in the ENDO of LVH hearts with or without ischemic coronary artery diseases, and whether these functional benefits are accompanied by regeneration of myocardium from both engrafted MSCs as well as endogenous CPCs. SA3: To examine whether the functional beneficial effects of cellular therapy are associated with the differential protein expression profle of the recipient myocardium. We will employ cutting edge liquid chromatography mass spectrometry-based comparative proteomics method to quantitatively determine the changes in the protein expression with a special emphasis on growth factors family proteins and proteins involved in energy metabolism. The findings of the experiments will elucidate for the first time, the transmural gradient of ATP turnover rate via both CK and ATPase in the in vivo LVH hearts. The findings of these studies will advance our understanding of the mechanisms of cellular therapy in myocardial repair, and lead to better diagnostic and therapeutic modalities for CHF patients.