PDF(Pubmed)
Abstract：
Hereditary Hemorrhagic Telangiectasia (HHT) is a rare congenital disease in which fragile vascular malformations (VM) - including small telangiectasias and large arteriovenous malformations (AVMs) - focally develop in multiple organs. There are few treatment options and no cure for HHT. Most HHT patients are heterozygous for loss-of-function mutations affecting Endoglin (ENG) or Alk1 (ACVRL1); however, why loss of these genes manifests as VMs remains poorly understood. To complement ongoing work in animal models, we have developed a fully human, cell-based microphysiological model based on our Vascularized Micro-organ (VMO) platform (the HHT-VMO) that recapitulates HHT patient VMs. Using inducible ACVRL1 -knockdown, we control timing and extent of endogenous Alk1 expression in primary human endothelial cells (EC). Resulting HHT-VMO VMs develop over several days. Interestingly, in chimera experiments AVM-like lesions can be comprised of both Alk1-intact and Alk1-deficient EC, suggesting possible cell non-autonomous effects. Single cell RNA sequencing data are consistent with microvessel pruning/regression as contributing to AVM formation, while loss of PDGFB implicates mural cell recruitment. Finally, lesion formation is blocked by the VEGFR inhibitor pazopanib, mirroring positive effects of this drug in patients. In summary, we have developed a novel HHT-on-a-chip model that faithfully reproduces HHT patient lesions and that can be used to better understand HHT disease biology and identify potential new HHT drugs.
摘要：
遗传性出血性毛细血管扩张症（HHT）是一种罕见的先天性疾病，其中脆性血管畸形（VM）-包括小毛细血管扩张和大动静脉畸形（AVM）-在多个器官中发生。很少有治疗选择，也没有治愈HHT的方法。大多数HHT患者是影响Endoglin（ENG）或Alk1（ACVRL1）的功能丧失突变的杂合子；然而，为什么这些基因的丢失表现为VM仍然知之甚少。为了补充正在进行的动物模型工作，我们已经开发了一个完全的人类，基于我们的血管化微器官（VMO）平台（HHT-VMO）的基于细胞的微生理模型，该模型概括了HHT患者的VM。使用诱导型ACVRL1敲低，我们控制了原代人内皮细胞（EC）中内源性Alk1表达的时间和程度。所得的HHT-VMOVM在几天内发展。有趣的是,在嵌合体实验中，AVM样病变可由完整的Alk1和缺乏Alk1的EC组成，提示可能的细胞非自主效应。单细胞RNA测序数据与微血管修剪/回归一致，有助于AVM形成。而PDGFB的丢失涉及壁细胞募集。最后,VEGFR抑制剂帕唑帕尼阻断病变形成，反映了这种药物对患者的积极作用。总之,我们开发了一种新型芯片上HHT模型,该模型能够忠实地再现HHT患者的病变,并可用于更好地了解HHT疾病生物学特性和鉴定潜在的新型HHT药物.字数：213分类。生物科学,细胞生物学。
