Related Experiment Video
Updated: Jun 9, 2026
iPSC-Derived Epithelial, Mesenchymal, Endothelial, and Immune Cell Co-Culture to Model Airway Barrier Integrity in Lung Health and Disease
Published on: December 6, 2024
Apical-out airway organoids as a pathophysiological model to study macrophage-mediated epithelial responses to
Seon Young Choi1, Chae Hwa Kim2, Soyoung Hwang1
1Department of Thoracic and Cardiovascular Surgery, Gachon University Gil Medical Center, College of Medicine, Gachon University, Incheon, 21565, Republic of Korea.
Abstract:
Respiratory exposure to airborne microplastics is increasingly implicated in airway inflammation, but human-relevant in vitro systems that separate direct epithelial particle contact from immune-cell-mediated paracrine effects remain limited. Here, we generated human airway basal stem cells (hABSCs)-derived apical-out airway organoids (AOAOs) with outward-facing ciliated surfaces and used them to evaluate operationally size-fractionated, polydisperse polystyrene microplastic (PS-MP) fractions. PS-MPs were characterized by laser diffraction, SEM, FT-IR, Nile red labeling, endotoxin testing, and culture-media stability/protein-adsorption assays. AOAOs were exposed under two submerged configurations: direct application of PS-MPs to the organoid surface or indirect exposure to conditioned media from PS-MP-treated THP-1-derived macrophages. CCK-8, MTT, and LDH range-finding assays identified 1 and 100 μg/mL as non-cytotoxic nominal submerged doses for macrophage-organoid experiments. Direct exposure of AOAOs to small, medium, or large PS-MP fractions did not induce marked TNF-α expression, mucin secretion, epithelial barrier disruption, or goblet cell hyperplasia. In contrast, the small PS-MP fraction showed the strongest macrophage association and induced extracellular IL-1β release; conditioned media from small PS-MP-exposed macrophages increased TNF-α expression and Muc5ac-positive goblet cell populations in AOAOs. Selective caspase-1 activation in the small 100 μg/mL condition, together with cleaved GSDMD immunoreactivity and LDC7559-sensitive IL-1β release, supported a caspase-1-associated, GSDMD-sensitive component of IL-1β secretion, but did not establish definitive canonical inflammasome activation. This AOAO platform provides a submerged mechanistic proof-of-concept for dissecting macrophage-conditioned airway epithelial remodeling by PS-MPs, while not representing aerosol deposition or inhalation-equivalent dosimetry.
