3.3 | Hedgehog-Gli1 signaling was activated in hypertrophic LF and highly associated with LF fibrosis
To elucidate the molecular pathway involved in LF fibrosis, we focused on Hedgehog-Gli1 signaling, as this pathway was previously reported to be involved in fibrosis of various diseases (Edeling et al., 2016). As expected, gene enrichment analysis indicated that Hedgehog signaling-related proteins including Gli1 and Shh were highly elevated in fibroblasts from LSCS, suggesting the activation of Hedgehog signaling in LF (Figure 3A-B). Furthermore, PCR and western blot analyses were performed to analyze the expression of Hedgehog signaling-related proteins in LF tissues from two groups. Consistently, both the mRNA (Figure 3C) and protein (Figure 3D and 3E) expression levels of Gli1 and Shh were more higher in LF samples from LSCS group than those in the LDH group (P<0.05). Meanwhile, we assessed the cellular source of Gli1 and Shh on the cell by immunohistochemical analysis of LF tissues. It was found that the number of cells positive for Gli1 and Shh were significantly elevated in the LSCS group as compared to LDH group (Figure 3F). Moreover, Gli1 mRNA and protein expression was positively correlated with the LF thickness (Figure 3G, P<0.05) and fibrosis score, respectively (Figure 3G, P<0.05). Collectively, these data suggested the activation of Sonic Hedgehog signaling in hypertrophic LF.