Comparing gene expression across primary human airway models for cystic fibrosis precision medicine

Rationale:Cultured human bronchial epithelia (HBE) are the gold standard model for assessing the efficacy of small molecule therapies in cystic fibrosis (CF). However, these cells are difficult to access, especially in young children. Human nasal epithelia (HNE) are used as a surrogate model although it is unknown whether HNE recapitulate the gene expression properties of HBE Objective: To investigate the similarities and differences in gene expression genome-wide between HBE and HNE with a focus on CF lung disease modifier genes. Methods: RNA-sequencing was conducted on paired cultured and naïve HNE and HBE (n=71 samples) collected from 21 patients with CF who underwent lung transplantation. Gene expression was first compared across cultured and naïve samples to assess the impact of the culturing process, then compared between cultured HNE and HBE. Co-expression relationships of CF modifier genes were compared between cultured HNE and HBE. Results: The culturing process had little impact on the expression level of CF lung disease modifier genes. These genes also showed significant equivalent expression between cultured HNE and HBE. Their co-expression relationships in cultured HNE and HBE overlapped significantly, suggesting the corresponding biological processes are consistent across the two tissues. Conclusions: CF lung disease modifier genes have similar expression profiles across cultured HNE and HBE. This supports the use of HNE as a surrogate airway model to investigate CF lung disease, modifier genes and enable investigation of CF precision medicine. Overall design: mRNA profile of paired human bronchial epithelia (HNE) and human nasal epithelia (HBE), cultured and uncultured