Modeling Dysfunctional Cellular Cross-Talk in Emphysema using a Disease-Relevant Alveolus-on-Chip

Emphysema entails the irreversible loss of the alveoli, resulting in reduced gas exchange. There are no treatments to halt or recover alveolar loss, and drug discovery is hindered by culture systems not replicating the complexity of disease processes. We aim to develop an Alveolus-on-Chip model with disease-relevant cells to study cellular cross-talk related to impaired tissue repair in emphysema. To this end we developed mediator cocktails to promote emphysema associated cellular subsets and hallmark processes. We cultured primary alveolar epithelial type-2 cells (AT2) and MRC-5 fibroblasts with emphysema associated compounds (i.e. TNFα, IL-1β, IFN-γ, and hedgehog (HH) signaling agonists). We then looked at presence of GLI1, IL7 (Wang 2023 Immunity), and levels of inflammatory markers (IL-6/IL-8) in the fibroblast cultures, as well as effects on AT2 survival and proliferation by measuring SP-C and IL-8 via qPCR and Immunofluorescent staining. Exposure of MRC-5 fibroblasts to HH signaling agonist SAG induced GLI1 expression, but pro-inflammatory mediators impaired this expression. IL7 gene expression was upregulated in the presence of pro-inflammatory cytokines, but did not translate to higher protein levels. AT2 cultures were negatively affected by culture with pro-inflammatory proteins, as shown by lower SP-C and elevated IL-8 expression. Culture with emphysema-related mediators results in phenotypical changes, yet optimization is required for pronounced dysfunctional phenotypes. These phenotypes will allow us to develop an Alveolus Chip model to study cellular cross-talk underlying emphysema pathology and test regenerative strategies. Supported by the NWO Perspective grant #P12-14.