Wang Joanna Y, Michki Sylvia N, Sitaraman Sneha, Banaschewski Brandon J, Jamal Reshma, Gokey Jason J, Lin Susan M, Katzen Jeremy B, Basil Maria C, Cantu Edward, Kropski Jonathan A, Zepp Jarod A, Frank David B, Young Lisa R
bioRxiv. 2024 Dec 14:2023.06.17.545390. doi: 10.1101/2023.06.17.545390.
Hermansky-Pudlak syndrome (HPS) is a genetic disorder of endosomal protein trafficking associated with pulmonary fibrosis in specific subtypes, including HPS-1 and HPS-2. Single mutant HPS1 and HPS2 mice display increased fibrotic sensitivity while double mutant HPS1/2 mice exhibit spontaneous fibrosis with aging, which has been attributed to HPS mutations in alveolar epithelial type II (AT2) cells. We utilized HPS mouse models and human lung tissue to investigate mechanisms of AT2 cell dysfunction driving fibrotic remodeling in HPS. Starting at 8 weeks of age, HPS mice exhibited progressive loss of AT2 cell numbers. HPS AT2 cell function was impaired and . Incorporating AT2 cell lineage tracing in HPS mice, we observed aberrant differentiation with increased AT2-derived alveolar epithelial type I cells. Transcriptomic analysis of HPS AT2 cells revealed elevated expression of genes associated with aberrant differentiation and p53 activation. Lineage tracing and organoid modeling studies demonstrated that HPS AT2 cells were primed to persist in a Krt8 reprogrammed transitional state, mediated by p53 activity. Intrinsic AT2 progenitor cell dysfunction and p53 pathway dysregulation are novel mechanisms of disease in HPS-related pulmonary fibrosis, with the potential for early targeted intervention before the onset of fibrotic lung disease.
赫尔曼斯基-普德拉克综合征(HPS)是一种内体蛋白运输的遗传性疾病,在特定亚型(包括HPS-1和HPS-2)中与肺纤维化相关。单突变的HPS1和HPS2小鼠表现出更高的纤维化敏感性,而双突变的HPS1/2小鼠随着年龄增长会出现自发性纤维化,这被认为是由于肺泡II型上皮(AT2)细胞中的HPS突变所致。我们利用HPS小鼠模型和人类肺组织来研究AT2细胞功能障碍驱动HPS纤维化重塑的机制。从8周龄开始,HPS小鼠的AT2细胞数量逐渐减少。HPS的AT2细胞功能受损,并且……在HPS小鼠中进行AT2细胞谱系追踪,我们观察到异常分化,源自AT2的肺泡I型上皮细胞增多。对HPS的AT2细胞进行转录组分析发现,与异常分化和p53激活相关的基因表达升高。谱系追踪和类器官建模研究表明,HPS的AT2细胞倾向于以由p53活性介导的Krt8重编程过渡状态持续存在。内在的AT2祖细胞功能障碍和p53通路失调是HPS相关肺纤维化疾病的新机制,在纤维化肺病发病前有进行早期靶向干预的潜力。