Division of Pulmonary and Critical Care Medicine.
Department of Integrative Biology and Physiology.
Am J Respir Crit Care Med. 2021 Apr 15;203(8):1006-1022. doi: 10.1164/rccm.202006-2169OC.
The cellular and molecular landscape and translational value of commonly used models of pulmonary arterial hypertension (PAH) are poorly understood. Single-cell transcriptomics can enhance molecular understanding of preclinical models and facilitate their rational use and interpretation. To determine and prioritize dysregulated genes, pathways, and cell types in lungs of PAH rat models to assess relevance to human PAH and identify drug repositioning candidates. Single-cell RNA sequencing was performed on the lungs of monocrotaline (MCT), Sugen-hypoxia (SuHx), and control rats to identify altered genes and cell types, followed by validation using flow-sorted cells, RNA hybridization, and immunofluorescence. Relevance to human PAH was assessed by histology of lungs from patients and via integration with human PAH genetic loci and known disease genes. Candidate drugs were predicted using Connectivity Map. Distinct changes in genes and pathways in numerous cell types were identified in SuHx and MCT lungs. Widespread upregulation of NF-κB signaling and downregulation of IFN signaling was observed across cell types. SuHx nonclassical monocytes and MCT conventional dendritic cells showed particularly strong NF-κB pathway activation. Genes altered in SuHx nonclassical monocytes were significantly enriched for PAH-associated genes and genetic variants, and candidate drugs predicted to reverse the changes were identified. An open-access online platform was developed to share single-cell data and drug candidates (http://mergeomics.research.idre.ucla.edu/PVDSingleCell/). Our study revealed the distinct and shared dysregulation of genes and pathways in two commonly used PAH models for the first time at single-cell resolution and demonstrated their relevance to human PAH and utility for drug repositioning.
常用肺动脉高压（PAH）模型的细胞和分子景观及其转化价值尚未被充分理解。单细胞转录组学可以增强对临床前模型的分子理解，并促进其合理使用和解释。为了确定和优先考虑 PAH 大鼠模型肺部中失调的基因、途径和细胞类型，以评估其与人类 PAH 的相关性，并确定药物再定位候选物。对单克隆毒素（MCT）、苏根低氧（SuHx）和对照大鼠的肺部进行单细胞 RNA 测序，以鉴定改变的基因和细胞类型，然后使用流式分选细胞、RNA 杂交和免疫荧光进行验证。通过对患者肺部的组织学评估以及与人类 PAH 遗传基因座和已知疾病基因的整合，评估其与人类 PAH 的相关性。使用连接图谱预测候选药物。在 SuHx 和 MCT 肺中鉴定出许多细胞类型中基因和途径的明显变化。在各种细胞类型中观察到 NF-κB 信号的广泛上调和 IFN 信号的下调。SuHx 非经典单核细胞和 MCT 传统树突状细胞表现出特别强烈的 NF-κB 途径激活。SuHx 非经典单核细胞中改变的基因在 PAH 相关基因和遗传变异中显著富集，并且确定了预测能够逆转这些变化的候选药物。开发了一个共享单细胞数据和候选药物的开放访问在线平台（http://mergeomics.research.idre.ucla.edu/PVDSingleCell/）。我们的研究首次以单细胞分辨率揭示了两种常用 PAH 模型中基因和途径的独特和共同失调，并证明了它们与人类 PAH 的相关性及其在药物重定位中的实用性。
