Bioenergetics in Hypertrophied and Remodeled Left Ventricle

描述（由申请人提供）：已知左心室壁（ENDO）的内层是最容易受到氧化应激的。我们假设通过肌酸激酶（CK）和ATP酶存在ATP生成速率储备的跨壁梯度，其中在ENDO中最低，导致LVH心脏的ENDO易感性。尽管人们对细胞治疗心肌修复的兴趣浓厚，但迄今为止，大多数研究报告都是为了修复或预防继发于冠状动脉疾病的心肌梗死心脏的左室功能障碍。考虑到50%以上的心脏移植CHF患者病因为非缺血性，在进行大规模临床试验之前，迫切需要使用非缺血性大动物模型进行研究。细胞治疗有益作用的机制尚未明确。移植率低是一个一致的发现。然而，长期观察到受体心脏左室收缩功能的改善。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表达的改变有关。比较两种继发于压力过载或梗死后左室重构的猪左室h模型，MSCs移植对左室收缩功能的影响（MRI）心肌灌注、心肌氧合水平（1H-MRS）；每两周检测一次ATP周转率（31P- MRS），连续8周，比较蛋白质组学检测受体心肌差异蛋白表达。具体目标是：采用最新开发的T1-nom P-31磁化饱和转移（MST）方法，检测LVH心脏ENDO中心肌ATP通过CK和ATP酶的周转率是否发生最严重的改变，其严重程度是否与左室功能障碍的严重程度呈线性相关。SA2。研究同种异体间充质干细胞移植的功能益处是否伴随着伴有或不伴有缺血性冠状动脉疾病的LVH心脏ENDO中通过CK和ATP酶产生ATP能力的改善，以及这些功能益处是否伴随着移植的间充质干细胞和内源性心肌细胞的心肌再生。目的：探讨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。我们将采用基于液相色谱质谱的比较蛋白质组学方法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。本实验结果将首次阐明体内LVH心脏中CK和ATP酶的ATP周转率的跨壁梯度。这些研究结果将促进我们对细胞治疗在心肌修复中的机制的理解，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.