Bioenergetics in Hypertrophied and Remodeled Left Ventricle

描述(申请人提供)：众所周知，左室壁(Endo)的内层最容易受到氧化应激的影响。我们假设通过肌酸激酶(CK)和ATPase的ATP产生率的储备存在跨壁梯度，而后者是Endo中最低的，导致LVH心脏的Endo易损性。尽管细胞疗法对心肌修复有着浓厚的兴趣，但到目前为止，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患者的左心功能障碍。鉴于超过50%的心脏移植CHF患者的病因是非缺血性的，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。细胞疗法的有益效果的潜在机制还没有很好的定义。植入率很低，这是一致的发现。然而，受体心脏的左心室收缩功能的长期改善是始终如一的。因此，除了移植细胞的心肌再生外，LV腔功能的改善也可能与受体心肌蛋白表达的变化有关。比较两种压力超负荷或心肌梗死后左室重构所致的猪左室肥厚模型，移植MSCs对左心室收缩功能(MRI)、心肌血流灌注、心肌氧合水平(1H-MRS)和三磷酸腺苷(31P-MRS)的影响，用比较蛋白质组学方法检测受体心肌的差异蛋白表达。具体目标是：SA1。应用新近发展的T1-NOM P-31磁化饱和转移(MST)方法，检测心肌细胞通过CK和ATPase的ATP转换率是否在LVH心脏的内分泌发生了最严重的改变，其严重程度是否与LV功能障碍的严重程度呈线性相关。SA2.目的：探讨同种异体骨髓间充质干细胞移植的功能益处是否伴随有或不伴有缺血性冠状动脉病变的左室肥厚心脏内皮细胞通过CK和ATPase产生三磷酸腺苷能力的提高，以及这些功能益处是否伴随着移植的骨髓间充质干细胞和内源性星形胶质细胞的心肌再生。SA3：研究细胞治疗的功能益处是否与受体心肌的差异蛋白表达有关。我们将利用尖端的液-质联用比较蛋白质组学方法来定量确定蛋白质表达的变化，重点是生长因子、家族蛋白质和参与能量代谢的蛋白质。这些实验结果将首次阐明在体左室肥厚心脏中，通过CK和ATPase实现的ATP转换率的跨壁梯度。这些研究的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法。

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.