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

项目总结 主动脉瓣狭窄(AVS)是一种进行性疾病，其特征是成纤维细胞样瓣膜间质细胞(VIC) 持续激活的肌成纤维细胞，导致病理性的主动脉瓣叶僵硬。AVS治疗 瓣膜置换手术，如果能确定小分子药物组合，就可以避免这种情况 以抑制持续的肌成纤维细胞激活。然而，调节持久性的分子机制 肌成纤维细胞的激活是未知的，可能因患者而异和/或因性别而异。我建议的R00 研究试图继续表征导致持续性的性别和患者特定差异 动静脉曲张时肌成纤维细胞的激活及抑制肌成纤维细胞激活的最佳药物组合 患者特定提示的功能。我们假设(I)男性和女性受害者反应的性别相关差异 机械线索和(Ii)在AVS患者血清中发现的特定于患者的生化线索有助于持续 小分子药物的激活和随后的肌成纤维细胞反应。在目标1(完成)中，我们有 特征基因逃脱X染色体失活，调节肌成纤维细胞的激活 女性受害者被植入了聚乙二醇水凝胶。在目标2(正在进行中)中，我们将生成持续激活的 人AVS患者血清中的肌成纤维细胞并确定VIC中的变化(例如，开放的染色质区域) 利用转座酶可及染色质检测患者特定血清因子引起的表观基因组 测序(ATAC-seq)。在目标3(建议)中，我们将确定小分子药物的最佳组合，以 利用差异进化抑制AVS患者血清存在下的持续性肌成纤维细胞激活 算法。总而言之，拟议的研究将解决对性别和精确度的迫切需求，这一需求尚未得到满足 识别肌成纤维细胞持久性的分子机制的医学方法，可能提供一种 通向非手术AVS治疗的桥梁。

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.