Investigating sex differences in persistent valvular myofibroblast activation using hydrogel culture substrates

项目摘要 主动脉瓣狭窄（AVS）是一种进行性疾病，其中成纤维细胞样瓣膜间质细胞（VIC）变得 持续激活的肌成纤维细胞，其导致病理性主动脉瓣叶硬化。AVS治疗 如果能够确定小分子药物组合， 以抑制持续的肌成纤维细胞活化。然而，调节持久性的分子机制， 肌成纤维细胞活化是未知的，可能因患者和/或性别而异。我的建议R 00 研究试图继续描述导致持续性的性别和患者特异性差异， 肌成纤维细胞活化，并优化药物组合，以抑制肌成纤维细胞活化， 患者特异性提示的功能。我们假设（i）男性和女性VIC反应的性别相关差异 机械线索和（ii）在AVS患者血清中发现的患者特异性生化线索有助于持续的 活化和随后的肌成纤维细胞对小分子药物的反应。在目标1（已完成）中，我们有 特征性基因逃避X染色体失活，调节肌成纤维细胞活化独特， 接种在PEG水凝胶上的雌性VIC。在目标2（进行中）中，我们将生成持续激活的 检测人AVS患者血清中的肌成纤维细胞并确定维克中的改变（例如开放染色质区域 由于患者特异性血清因子导致的表观基因组，使用转座酶可降解染色质测定， 测序（ATAC-seq）。在目标3（拟定）中，我们将确定小分子药物的最佳组合， 在存在AVS患者血清的情况下使用差异进化抑制持续的肌成纤维细胞活化 算法总之，拟议的研究将解决对性别特异性和精确性的迫切而未满足的需求。 用于确定肌成纤维细胞持久性的分子机制的医学方法，这可能提供一个 为非手术AVS治疗搭建桥梁。

PROJECT SUMMARY Aortic valve stenosis (AVS) is a progressive disease where fibroblast-like valvular interstitial cells (VICs) become persistently activated myofibroblasts, which contribute to pathologic aortic valve leaflet stiffening. AVS is treated with valve replacement surgeries, which may be avoided if small molecule drug combinations could be identified to inhibit persistent myofibroblast activation. However, the molecular mechanisms regulating persistent myofibroblast activation are unknown and may vary from patient-to-patient and/or by sex. My proposed R00 research seeks to continue characterizing the sex- and patient-specific differences that lead to persistent myofibroblast activation during AVS and optimize drug combinations to inhibit myofibroblast activation as a function of patient-specific cues. We hypothesize (i) sex-linked differences in how male and female VICs respond to mechanical cues and (ii) patient-specific biochemical cues found in AVS patient sera contribute to persistent activation and subsequent myofibroblast response to small molecule drugs. In Aim 1 (completed), we have characterized genes that escape X-chromosome inactivation that regulate myofibroblast activation uniquely in female VICs seeded on PEG hydrogels. In Aim 2 (in progress), we will generate persistently activated myofibroblasts in human AVS patient sera and determine alterations (e.g. open chromatin regions) in the VIC epigenome due to patient-specific serum factors using Assay for Transposase-Accessible Chromatin with sequencing (ATAC-seq). In Aim 3 (proposed), we will identify optimal combinations of small molecule drugs to inhibit persistent myofibroblast activation in the presence of AVS patient serum using a differential evolution algorithm. In sum, the proposed research will address an urgent, unmet need for sex-specific and precision medicine approaches for identifying molecular mechanisms of myofibroblast persistence, which may provide a bridge toward non-surgical AVS therapies.