Modeling Marfan Syndrome with iSMC-based Tissue-engineered Blood Vessel

摘要 血管平滑肌细胞（SMC）在包括马凡氏综合征（MFS）在内的主要血管疾病的进展中起着关键作用，MFS是一种由FBN 1基因突变引起的遗传性疾病，发生率为1/5000 [1]。MFS可导致危及生命的胸主动脉瘤（TAA）[2]。SMC在收缩表型和合成增殖表型之间的转换中显示出独特的可塑性，使其能够调节血管张力和血压。此外，SMC功能与TGFOB信号传导密切相关，TGFOB信号传导是参与MFS的主要途径。因此，了解SMC在MFS中的作用将是制定MFS有效治疗策略的富有成效的方法。然而，这通常是困难的，因为SMC具有有限的增殖能力并且在培养中迅速衰老[5]。利用NHLBI生物样本和数据库中来自多个MFS患者的外周血单核细胞（PBMC），我们建议将从PBMC分离的内皮祖细胞（EPC）转分化为诱导的SMC（iSMC）用于MFS的疾病建模。本项目的目的是（i）建立一个强大的系统，从MFS患者的PBMC中产生iSMC，以及（ii）制造基于内皮化iSMC的组织工程血管（TEBViSMC），可以重现MFS血管的病理生理学。我们将评估在灌注下对MFS相关药物反应的血管活性功能。我们还将评估iSMC的表观遗传稳定性，以了解细胞来源和供体依赖性遗传变异对血管疾病模型系统保真度的潜在影响。如果成功的话，这种患者特异性的体外血管模型可以帮助研究MFS，筛选潜在的药物，并为MFS制定有效的治疗策略。

Abstract Vascular smooth muscle cells (SMC) play a key role in the progression of major vascular diseases including Marfan syndrome (MFS), which is a genetic disorder caused by a mutation in the FBN1 gene that occurs in 1 in 5000 people [1]. MFS can lead to thoracic aortic aneurysm (TAA) that is life threatening [2]. SMC display unique plasticity in switching between a contractile phenotype and a synthetic proliferative phenotype, allowing them to regulate the vessel tone and blood pressure. In addition, SMC function is closely linked with TGFOB signaling, which is a major pathway involved in MFS. Thus, understanding the role of SMC in MFS would be a fruitful approach to develop effective therapeutic strategies for MFS. However, it is often difficult because SMC have limited proliferative capacity and acquire senescence rapidly in culture [5]. Leveraging on access to peripheral blood mononuclear cells (PBMC) from multiple MFS patients at the NHLBI Biologic Specimen and Data Repository, we propose to transdifferentiate endothelial progenitor cells (EPC) isolated from PBMC into induced SMC (iSMC) for disease modeling of MFS. The objectives of this project are (i) to establish a robust system to generate iSMC from the PBMC of MFS patient, and (ii) to fabricate endothelialized iSMC-based tissue-engineered blood vessels (TEBViSMC) that can recapitulate the pathophysiology of MFS blood vessels. We will assess the vasoactive function in response to MFS-related drugs under perfusion. We will also evaluate the epigenetic stability of iSMC to understand the potential impact of cell origin and donor-dependent genetic variants on the fidelity of the vascular disease model system. If successful, this patient-specific in vitro vascular model can help study MFS, screen for potential drugs, and develop effective therapeutic strategies for MFS.