Integrated multiomic analysis identifies TRIP13 as a mediator of alveolar  epithelial type II cell dysfunction in idiopathic pulmonary fibrosis
Idiopathic pulmonary fibrosis (IPF) is a lethal progressive lung disease urgently needing new therapies. Current treatments only delay disease progression, leaving lung transplant as the sole remaining option. Recent studies support a model whereby IPF arises because alveolar epithelial type II (AT2) cells, which normally mediate distal lung regeneration, acquire airway and/or mesenchymal characteristics, preventing proper repair. Mechanisms driving this abnormal differentiation remain unclear. We performed integrated transcriptomic and epigenomic analysis of purified AT2 cells which revealed genome-wide alterations in IPF lungs. The most prominent epigenetic alteration was activation of an enhancer in thyroid receptor interactor 13 (TRIP13), coinciding with TRIP13 upregulation. TRIP13 is broadly implicated in epithelial-mesenchymal plasticity and transforming growth factor-beta signaling. In cultured human AT2 cells and lung slices, small molecule TRIP inhibitor DCZ0415 prevented acquisition of the mesenchymal gene signature characteristic of IPF, suggesting TRIP13 inhibition as a potential therapeutic approach to fibrotic disease. Overall design: AT2 cells purified from primary human normal and IPF samples underwent bulk RNAseq and bulk ATACseq profiling and data integration to determine the extent and effect of epigenomic remodeling on AT2 biology in IPF. Bulk ATACseq was also performed on primary proximal lung basal cells.