Anti-fibrotic effect of ciglitazone in HRV-induced airway remodelling cell model

Fibrosis is an important phenomenon as it can occur early in the pathogenesis of asthma; it may be associated with disease severity and resistance to therapy. There is a strong evidence that infection caused by human rhinovirus (HRV) contributes to remodelling process, but there is lack of studies clearly explaining this pathway. Synthetic peroxisome proliferator-activated receptor (PPAR) γ presents immunomodulatory and anti-inflammatory features. In this study, we examined immunomodulatory properties of ciglitazone - PPAR-γ agonist, in development and modulation of airway remodelling. Epithelial cells (NHBE) and two lines of fibroblasts (WI-38, HFL1) were stimulated with ciglitazone and rhinovirus. The expression of genes related to airway remodelling process were analysed in the cells; moreover NF-κB, c-Myc and STAT3 were silenced in order to estimate potential pathways involved. Ciglitazone decreased mRNA expression of MMP-9 and TGF-β. It also modified the expression of α-SMA and collagen after rhinovirus infection. Transcription factors knockdown altered the levels of expression. The results suggest possible anti-fibrotic activity of PPAR-γ agonist in human airway cells. Ciglitazone has been shown to be dependent on NF-κB- and STAT3-related pathways, thus, the PPAR-γ agonist may have therapeutic potential for the treatment of airway remodelling in asthma.