Identification of Novel Modulators of Airway Proliferation and Differentiation

Abstract

The human lung’s airway epithelium, compromising of pseudostratified cells, is essential for maintaining respiratory function. These cells proliferate and differentiate into diverse cell types necessary for a functional epithelium. However, the regulatory mechanisms controlling their proliferation, self-renewal, and differentiation are not fully understood, this presents a significant opportunity to develop targeted therapeutic strategies to enhance airway tissue repair and regeneration. To explore this, High- throughput screening methods have identified, a promising compound. One candidate is Leflunomide, inhibits a potential therapeutic agent. Leflunomide exerts its effects by inhibiting dihydroorotate dehydrogenase. This study investigated in vitro the effects of Leflunomide on the expression of Wnt-pathway associated genes LEF1, AXIN2, c- myc, and cyclin D1 in HBECs obtained from various donors. Primary HBECs cultures were optimised, and gene expression analysis was conducted using Quantitative PCR with normalisation to the housekeeping genes RSP13 and GAPDH. Fold changes in gene expression were determined using the 2-∆∆CT method. Leflunomide treatment showed a notable increase in AXIN2 gene expression in the HBEC cell line, suggesting activation of the Wnt signalling pathway. However, other genes, including LEF1, c-myc, and cyclinD1, did not show significant expression changes across different donor cell lines. This suggests that while Leflunomide may influence certain aspects of the Wnt-pathway, its effects are selective rather than broad. Further in vivo studies are needed to fully understand the therapeutic potential of Leflunomide and to evaluate its ability to effectively promote airway epithelial repair by modulating the Wnt pathway, supporting its repurposing for the treatment of airway dysfunction diseases.