Multi-Omics Approach to Identify Cardiokines in Human iPSC Models

人类心脏主动地将蛋白质信使释放到细胞外空间。最近的研究表明 这些被称为心脏激活素的分泌蛋白可以介导起重要作用的细胞串扰 在心肌病和心力衰竭的发展中起重要作用。尽管一些经典的心脏激动剂，如 利钠肽已经得到了广泛的表征，但很少有人努力系统地 对人类心脏细胞分泌的蛋白质进行分类。利用蛋白质组学和人类诱导多能性 干细胞(HiPSC)模型，我们最近通过以下方式创建了人类心脏分泌组的草图 鉴定和对比来自HiPSC来源的心肌细胞，心脏成纤维细胞， 和内皮细胞。结果显示，释放的候选心脏激动素数量惊人地多 来自每种细胞类型，包括许多在心血管中具有未知功能的分泌蛋白 系统。此外，我们发现心肌细胞携带扩张剂的分泌模式发生了广泛的变化。 心肌病的因果变异高于正常细胞。在这些发现的基础上，我们在R00阶段的目标 现在正致力于(I)：识别在成纤维细胞串扰中起作用的心肌细胞分泌蛋白，并预测 它们调节的生物过程；以及(2)优先考虑与疾病相关的心脏因子，并确认其效果 对受体成纤维细胞基因表达的影响。为达致这些目标，我们会综合运用 以HiPSC模型为基础的计算、单细胞测序和蛋白质组学策略 基金会。如果成功，这项拟议的研究有可能揭开一些新的秘密 蛋白质及其在人类心肌细胞中的功能，并阐明了细胞通讯在 心肌病的发展和进展。

The human heart actively releases protein messengers into the extracellular space. Recent work suggests that these secreted proteins, termed cardiokines, can mediate cellular crosstalk that plays important roles in the development of cardiomyopathies and heart failure. Although several classical cardiokines such as the natriuretic peptides have been extensively characterized, there have been few efforts to systematically catalog the proteins secreted by human cardiac cells. Using proteomics and human induced pluripotent stem cell (hiPSC) models, we recently created a draft map of the human cardiac secretome through identifying and contrasting secreted molecules from hiPSC-derived cardiomyocytes, cardiac fibroblasts, and endothelial cells. The results revealed a surprisingly large number of candidate cardiokines released from each cell type including many secreted proteins with uncharacterized function in the cardiovascular system. Moreover, we found broad changes in the secretome patterns of cardiomyocytes carrying dilated cardiomyopathy causal variants over normal cells. Building on these findings, our aims in the R00 phase are now to (i): identify cardiomyocyte secreted proteins that function in fibroblast crosstalk and predict the biological processes they regulate; and (ii) prioritize disease-relevant cardiokines and validate their effects on recipient fibroblast gene expression. To achieve these aims, we will employ a combination of computational, single-cell sequencing, and proteomics strategies building on hiPSC models as our foundation. If successful, the proposed research has the potential to uncover a number of novel secreted proteins and their function in human cardiac cells, and shed light on the role of cellular communications in the development and progression of cardiomyopathies.