RNA Sequencing Provides Insight Into Idiopathic Subglottic Stenosis.

OBJECTIVES

Determination of differential gene expression in idiopathic subglottic stenosis.

METHODS

Subglottic and tracheal tissues were collected from 19 prospectively recruited patients with laryngotracheal stenosis undergoing surgery: 11 patients with idiopathic subglottic stenosis (iSGS) and 8 patients with post-intubation laryngotracheal stenosis (iLTS). Total RNA was extracted from specimens. Bulk RNA sequencing (RNAseq) was done. Differential gene expression analyses were carried out using DESeq2. Bioinformatic approaches were utilized to gain insight into pathways significant for iSGS.

RESULTS

There were 68 differentially expressed genes (DEGs) between iSGS females and iLTS females. Gene Set Enrichment Analysis (GSEA) revealed that epithelial-mesenchymal transition (EMT) was the most upregulated pathway in iSGS pathogenesis compared to iLTS. The most downregulated pathway in iSGS compared to iLTS was TNFα signaling via NF-κB. Candidate DEGs in iSGS were selected based on GSEA of Hallmark gene sets. Gene Ontology enrichment analysis of these 32 candidate DEGs revealed that significant biological pathways included cell-cell adhesion and neutrophil aggregation. KEGG database identified IL-17 signaling to be the most enriched pathway among the candidate genes.

CONCLUSIONS

This pilot study corroborated the significance of EMT as the most upregulated pathway in iSGS. Inflammatory pathways were more upregulated in the pathogenesis of iLTS compared to iSGS. Candidate DEGs encoding integral membrane proteins were downregulated in iSGS compared to iLT. IL-17 signaling played an important role in both iSGS and iLTS. The roles of innate immunity remain to be defined in iSGS.