"Glycoprotein involvement in cardiac fibrobiast-myocyte communication "

冠状动脉的阻塞可导致心脏病发作（急性心肌梗塞; MI）， 心肌组织的永久性丧失。对复杂心脏结构的破坏， 疤痕组织的形成和心肌重塑增加了死亡风险。心脏最初的反应 损伤是同步的，并且部分涉及心脏成纤维细胞和 肌细胞，这两种主要细胞类型构成心脏。最近的研究表明，可溶性蛋白质 由心脏成纤维细胞和肌细胞分泌的，也称为分泌体，可以调节梗死 微环境（细胞外基质，ECM）。正是细胞表面不仅作为物理屏障 但感觉到局部ECM微环境，启动内在的细胞保护机制， 损伤因此，细胞-环境界面是这种相互作用的主要场所。我们假设 成纤维细胞是关键，它们对损伤的反应启动伤口愈合，同时也促进肌细胞 生存成纤维细胞通过改变肌细胞周围的ECM微环境来实现这一点， 尤其是存在于梗塞边缘区的那些。构成细胞环境的许多蛋白质 界面被糖基化。在这份提案中，我们将运用多项创新方法，有针对性地丰富、 定量（相对和绝对）和表征细胞-环境界面的糖蛋白质组， 单独的肌细胞和成纤维细胞以及在有和没有H2 O2诱导的损伤的情况下的共培养。这包括使用 共培养时的新转折，其中来自一种细胞类型的蛋白质具有共价定量标记， 其提供了质谱友好的标记物以区分每种蛋白质的细胞来源。我们 假设构成细胞-环境界面细胞特异性糖蛋白质组负责 与成纤维细胞相比，肌细胞对H2 O2的固有易感性（SA 1）。此外， 在共培养物中升高的成纤维细胞特异性分泌蛋白诱导肌细胞保护， 当成纤维细胞自身受到损伤时，保护性表型通过作用而增强（SA-2）。最后， 我们假设，存在于微环境中的糖蛋白， H2 O2的反应将在心肌损伤（缺血）患者的循环中检测， 心肌肌钙蛋白（MI的金标准标志物）升高。总而言之， 对于心脏成纤维细胞或肌细胞，细胞-环境界面尚未完全阐明。这 知识是开发保护心脏的临床方法的基础， 稳健的临床生物标志物 相关性（参见说明）; 这是第一次系统地分析糖蛋白，这些糖蛋白包括分泌组和细胞表面， 心肌细胞和成纤维细胞，心脏的两种主要细胞类型，它们的相互作用是协同的， 导致肌细胞保护。这些保护性糖蛋白可能是适合治疗的靶点。 干预此外，心肌和心脏成纤维细胞特异性低氧刺激分泌蛋白 来自心肌缺血患者循环和升高的心脏成纤维细胞和肌细胞

The blockage of coronary arteries can result in a heart attack (acute myocardial infarction; Ml) and permanent loss of cardiac muscle tissue. The resulting destruction of the complex cardiac architecture, formation of scar tissue, and myocardial remodeling increases risk of death. The heart's initial response to injury is synchronous and involves, in part, the reciprocal interaction between cardiac fibroblasts and myocytes, the two primary cell types comprising the heart. Recent findings suggest that soluble proteins secreted from cardiac fibroblasts and myocytes, also called the secretome, can modulate the infarct microenvironment (extracellular matrix, ECM). It is the cell surface that not only acts as a physical barrier but senses of the local ECM microenvironment that initiates the intrinsic cellular protective mechanisms upon injury. Thus, the cell-environment interface is the main site of this interplay. We hypothesize that fibroblasts are the linchpin and their respond to injury launches wound healing while also promoting myocyte survival. Fibroblasts accomplish this by altering the ECM microenvironment surrounding myocytes, especially those present in the infarct border zone. Many of the proteins comprising cell-environment interface are glycosylated. In this proposal, we will use a number of innovative methods to target, enrich, quantify (relative and absolute) and characterize the glycoproteome of the cell-environment interface of myocytes and fibroblasts alone and in co-culture with and without injury induced by H2O2. This includes using a novel twist when co-culturing, in which the proteins from one cell type have a covalent quantitative labeled which provides a mass spectrometry friendly marker to distinguishing the cell origin of each protein. We hypothesize that cell-specific glycoproteome comprising the cell-environment interface is responsible to the intrinsic susceptibility to H2O2 of myocytes compared to fibroblasts (SA 1). Furthermore, that a subset of the fibroblast-specific secreted proteins which are elevated in co-culture induces myocyte-protection and this protective phenotype is enhanced by the action of when fibroblast, themselves are injured (SA-2). Finally, we hypothesize that glycoproteins present in the microenvironment which are exclusively elevated in response of H2O2 will be detected in the circulation of patients with myocardial injury (ischemia) prior to the elevation of cardiac troponins (gold standard markers for Ml). In summary, the protein complement of the cell-environment interface has not been fully elucidated for either cardiac fibroblasts or myocytes. This knowledge is fundamental to developing clinical approaches to protect the heart and potentially provide robust clinical biomarkers RELEVANCE (See instructions); This is the first systematic analysis of the glycoproteins which comprise the secretome and cell surface of myocytes and fibroblast, two major cell types of the heart, for which their interaction is synergetic and can results in myocyte protection. These protective glycoproteins could be targets suitable for therapeutic intervention. As well, the myocardial and cardiac fibroblast specific hypoxic stimulated secreted proteins from cardiac fibroblasts and myocytes that circulating and are elevated in patients with myocardial ischemia