# Establishing an Ex Vivo Culture Model of Human Proximal Airway Tissue

## TL;DR

Researchers developed a new ex vivo model to culture human airway tissue, which could help study airway diseases and test therapies.

## Contribution

A reproducible ex vivo culture method for human proximal airway tissue that maintains viability and function for three days.

## Key findings

- The new culture method preserved epithelial viability and morphology better than standard methods.
- The model showed active glycoprotein synthesis in the epithelium, indicating cellular activity.
- Control tissues showed acidosis and epithelial damage, highlighting the model's superiority.

## Abstract

Background: Developing clinically relevant experimental models of the human airway can significantly advance our understanding of the mechanisms underlying airway diseases and aid in translating potential therapies to clinical settings. The aim of this study is to establish an ex vivo human airway tissue culture model. Methods: Human donor airway tissues were obtained from clinical cases of lung transplantation. Our established method is based on the concept of scavenging metabolic activity and controlling bacterial growth and includes increased media volume, frequent media exchange, and antifungal additives to efficiently maintain the homeostatic culture environment. After a 3-day culture period, the airway was investigated, and its viability and function were compared with a standard cell culture method. Results: Control tissue exhibited significant acidosis after 3 days, suggesting high metabolic activity of airway tissue and bacterial contamination. The airway epithelial viability—after culturing in our established method for 3 days—was better than that of the controls. We only performed an acute but early investigation of the cultures as airway complications have been known to start early at the proximal bronchus after transplantation. H&E and alcian blue staining showed intact morphology of the epithelium of airway tissue and mucus layers after 3 days in our model, while controls showed remarkable damage to the epithelial layer. Newly synthesized glycoproteins were detected in the epithelial layer using metabolic labeling and the click chemistry technique, suggesting cellular protein synthesis of the airway tissue in our established ex vivo model. Conclusions: We successfully established a reproducible model of human ex vivo airway tissue culture (n = 3 independent biological samples) that may be useful for investigating airway complications and developing their therapies.