Southern California Stem Cell Seminar series, Dr. Le Xu, presents "A Tale of Two Barriers: Plasticity of Lung Epithelium and Mesothelium." 

Le Xu, PhD, Research: Two barrier tissues in the lung, the epithelium on the surface of the airway and mesothelium outlining the organ boundary, sandwich the rest of the cells in between. Many lung diseases manifest and progress from these barrier tissues or space adjacent to them, such as COPD and IPF.

In this talk, Dr. Xu will present his recent findings on the cellular and molecular mechanisms underlying the control of cell fate, behavior, and plasticity of these two barrier tissues. In airway epithelium, he found that mitochondria controlled epithelial cell proliferation, survival or migration in a context-dependent manner. Impaired mitochondrial function led to progressive airway remodeling recapitulating COPD pathology. In mesothelium, he found that this quiescent, single-cell layer tissue underwent ectopic expansion and differentiation during lung regeneration post-pneumonectomy (PNX). Multimodal single cell deconvolution revealed that this activated cells at organ boundary function as a signaling hub that orchestrates lung regeneration. Cells with conserved spatial and molecular signatures are identified in human IPF, suggesting its disease relevance. Future directions, including new mouse models of lung regeneration, spatial omics, and translational medicine, will be further discussed.