Fig. 5

TNF-α increased lumican expression in HLF and lumican triggered fibroblast-to-myofibroblast transition and epithelial-mesenchymal transition. (A) Lumican mRNA levels were assessed by real-time reverse transcription polymerase chain reaction. (B) Lumican protein level was measured using enzyme-linked immunosorbent assay in cell culture supernatants. When lumican was incubated with HLF, expression levels of α-SMA, COL1A1, and COL3A1 mRNA were higher than those in control cells (C), as were the levels of α-SMA, Slug, and phosphorylated ERK protein (D). After culture with lumican for 24 h, SAECs changes to a spindle-like morphology (E). Scale bar, 50 μm. E-cadherin, α-SMA, and COL3A1 mRNA expression in lumican-treated SAECs are shown in (F). Representative protein levels in control cells and lumican-treated SAECs are shown as Western blots (G). Three independent experiments were conducted with triplicate wells per treatment in each experiment. The difference between two groups was examined using the unpaired t-test (n = 3). Values are expressed as the mean and standard deviation. The significance of between-group differences was examined using one-way analysis of variance followed by Tukey's multiple comparisons test to analyse the means of multiple samples. p < 0.05 was considered statistically significant. *p < 0.05, **p < 0.01, ***p < 0.005. α-SMA alpha-smooth muscle actin, COL1A1 alpha-1 type I collagen, COL3A1 alpha-1 type III collagen, HLF primary human lung fibroblasts, SAECs small airway epithelial cells, TNF-α tumour necrosis factor-alpha