Hydrogels to Study Synergistic Effects of Signaling Factors and Matrix Mechanics on Valve Disease Progression

瓣膜间质细胞（VIC）的肌成纤维细胞活化被认为是心脏病的主要驱动因素。 瓣膜纤维化和狭窄。出于这个原因，外部线索，以控制 VIC的肌成纤维细胞表型已经成为本领域相当关注的主题。 越来越多的证据表明，除了受体介导的可溶性生长激活VIC外， 在这一过程中，来自母体的物理线索起着关键作用。不幸的是，传统 用于培养VIC的方法固有地导致它们的肌成纤维细胞活化， 变得难以确定环境刚度对激活的影响， 去激活为了解决这个问题，我们的团队已经证明，独特的水凝胶材料 可用于制造用于维克培养的柔软的非活化基质， 表型更接近于新鲜分离的细胞。现在，我们的目标是研究如何 基质硬度与促炎细胞因子联合影响维克成纤维细胞对 肌成纤维细胞转变，这些细胞随时间推移可能发生的表观遗传变化，以及 可能有助于逆转致病性肌成纤维细胞 表型具体而言，我们建议：1）使用组合方法来研究 促炎细胞因子对维克表型的影响，作为微环境刚度的函数2） 确定机械和炎症因素对成纤维细胞到肌成纤维细胞的影响 使用具有动态可调机械性能的水凝胶的转变及其逆转，以及3） 发现新的分子靶点用于治疗以缓和致病性维克肌成纤维细胞 在炎症条件下活化。在这些目标范围内完成的工作 将为纤维化主动脉瓣狭窄的进展提供独特的见解。建立 可调的细胞培养平台将使我们能够回答关于 可逆性（一过性，伤口愈合状态）和不可逆性（持续性，致病状态）维克 肌成纤维细胞不能用传统方法充分解决。后续 对信号通路和基因的分析将用于确定治疗的新靶点。 逆转维克激活和治疗瓣膜疾病的潜力。此外，圆满完成 这些目的应该是医学领域普遍感兴趣的，因为纤维化的机制是 可能是大多数纤维化相关疾病的共同特征。

Myofibroblast activation of Valvular Interstitial Cells (VICs) is considered to be a primary driver of valvular fibrosis and stenosis. For this reason, the external cues that act to control the myofibroblast phenotype of VICs have been topics of considerable attention in the field. Increasing evidence suggests that beyond receptor-mediated activation of VICs by soluble growth factors, physical cues from the matrix play a critical role in this process. Unfortunately, traditional methods used to culture VICs inherently leads to their myofibroblast activation, such that it becomes difficult to determine the effects of environmental stiffness on activation and especially de-activation. To address this issue, our group has demonstrated that unique hydrogel materials can be used to create soft, non-activating substrates for VIC culture that allow VICs to maintain a phenotype that more closely resembles that of freshly isolated cells. Now, we aim to examine how matrix stiffness in combination with pro-inflammatory cytokines influence the VIC fibroblast-to- myofibroblast transition, the epigenetic changes that may occur to these cells over time, and the pathways in matrix signaling that might be useful in reversing the pathogenic myofibroblast phenotype. Specifically, we propose to: 1) Use a combinatorial approach to study the effect of pro-inflammatory cytokines on VIC phenotypes as a function of microenvironmental stiffness 2) Identify the effects of mechanical and inflammatory cues on the fibroblast-to-myofibroblast transition and its reversal using hydrogels with dynamically tunable mechanical properties, and 3) Discover new molecular targets for therapeutics to temper pathogenic VIC myofibroblast activation under inflammatory conditions. Together, work completed within each of these Aims will provide unique insight into the progression of fibrotic aortic valvular stenosis. The creation of tunable cell culture platforms will allow us to answer questions about differences between reversible (transient, wound healing state) and irreversible (persistent, pathogenic state) VIC myofibroblasts that cannot be adequately addressed with traditional methods. Subsequent analysis of the signaling pathways and genes will be used to identify new targets with therapeutic potential to reverse VIC activation and treat valve disease. Moreover, successful completion of these Aims should be of general interest to the field of medicine, as mechanisms of fibrosis are likely shared among most fibrosis-related diseases.