The heterogeneity of fibroblasts in laryngotracheal stenosis and skin hypertrophic scar in pediatric patients

Objectives: To investigate the heterogeneity between the laryngotracheal stenosis and hypertrophic scar derived fibroblasts. Methods: Human laryngotracheal stenosis (LTS) and skin hypertrophic scar (HTS) specimens were obtained during the tracheal resection and T-shaped tracheal stent implantation surgery. Fibroblasts were isolated and cultured. Cell proliferation and migration were analyzed by cell count, EdU proliferation and wound-healing assays. The expressions of COL1a1, alpha-SMA, TGF-beta 1 signaling pathway, chemokines and receptors were analyzed by qRT-PCR, western blotting, and immunohistochemistry. Results: Cell proliferation and migration of LTS derived fibroblasts were significantly faster than HTS fibroblasts, with no significant difference of the percentage of apoptotic cells. COL1a1, alpha-SMA, and Integrins were downregulated in LTS fibroblasts, but TGFB1 and chemokine receptor CXCR7 were up-regulated in LTS fibroblasts. However, the expressions of SMAD4 and phospho-SMAD2/3 were not significantly different. Conclusions: Human LTS and HTS derived fibroblasts differ in cell proliferation and migration. Different expressions of COL1a1, alpha-SMA, and CXCR7 were found between the two fibroblasts.