Bronchial epithelium epithelial-mesenchymal plasticity forms aberrant basaloid-like cells in vitro.

Document Type

Article

Publication Date

6-2022

Publication Title

American journal of physiology. Lung cellular and molecular physiology

Keywords

JGM, JMG, Epithelial Cells, Epithelial-Mesenchymal Transition, Epithelium, Humans, Lung Diseases, RNA, Long Noncoding, Respiratory Mucosa

JAX Source

Am J Physiol Lung Cell Mol Physiol 2022 Jun; 322(6):L822-L841

Volume

322

Issue

6

First Page

822

Last Page

822

ISSN

1522-1504

PMID

35438006

DOI

https://doi.org/10.1152/ajplung.00254.2021

Grant

AI142733, AI133440, AI141609

Abstract

Although epithelial-mesenchymal transition (EMT) is a common feature of fibrotic lung disease, its role in fibrogenesis is controversial. Recently, aberrant basaloid cells were identified in fibrotic lung tissue as a novel epithelial cell type displaying a partial EMT phenotype. The developmental origin of these cells remains unknown. To elucidate the role of EMT in the development of aberrant basaloid cells from the bronchial epithelium, we mapped EMT-induced transcriptional changes at the population and single-cell levels. Human bronchial epithelial cells grown as submerged or air-liquid interface (ALI) cultures with or without EMT induction were analyzed by bulk and single-cell RNA-Sequencing. Comparison of submerged and ALI cultures revealed differential expression of 8,247 protein coding (PC) and 1,621 long noncoding RNA (lncRNA) genes and revealed epithelial cell-type-specific lncRNAs. Similarly, EMT induction in ALI cultures resulted in robust transcriptional reprogramming of 6,020 PC and 907 lncRNA genes. Although there was no evidence for fibroblast/myofibroblast conversion following EMT induction, cells displayed a partial EMT gene signature and an aberrant basaloid-like cell phenotype. The substantial transcriptional differences between submerged and ALI cultures highlight that care must be taken when interpreting data from submerged cultures. This work supports that lung epithelial EMT does not generate fibroblasts/myofibroblasts and confirms ALI cultures provide a physiologically relevant system to study aberrant basaloid-like cells and mechanisms of EMT. We provide a catalog of PC and lncRNA genes and an interactive browser (https://bronc-epi-in-vitro.cells.ucsc.edu/) of single-cell RNA-Seq data for further exploration of potential roles in the lung epithelium in health and lung disease.

Comments

We gratefully acknowledge the contribution of Diane Luo from the Single Cell Biology service and the Genome Technologies service at The Jackson Laboratory for expert assistance with the work described in this publication. The authors thank Professors Wuyts and Vanaudenaerde from KU Leuven for providing the tissues.

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