Background： Follistatin-like I （FSTL 1） is a novel profibrogenic factor that induces pulmonary fibrosis （PF） through the transforming growth factor-beta 1 （TGF-[B 1 ）/Smad signaling. Little is known about its e...Background： Follistatin-like I （FSTL 1） is a novel profibrogenic factor that induces pulmonary fibrosis （PF） through the transforming growth factor-beta 1 （TGF-[B 1 ）/Smad signaling. Little is known about its effects on PF through the non-Smad signaling, like the mitogen-activated protein kinase （MAPK） pathway. Therefore, this study aimed to investigate the role ofFSTL 1 in PF through the MAPK signaling pathway and its mechanisms in lung fibrogenesis. Methods： PF was induced in Fstll~ and wild-type （WT） C57BL/6 mice with bleomycin. After 14 days, the mice were sacrificed, and lung tissues were stained with hematoxylin and eosin; the hydroxyproline content was measured to confirm PF. The mRNA and protein level of FSTLI and the change of MAPK phosphorylation were measured by quantitative polymerase chain reaction and Western blotting. The effect of Fst11 deficiency on fibroblasts differentiation was measured by Western blotting and cell immunofluorescence. MAPK signaling activation was measured by Western blotting in Fst11＋/ and WT fibroblasts treated with recombinant human FSTLI protein. We pretreated mouse lung fibroblast cells with inhibitors of the extracellular signal-regulated kinase （ERK）, p38, and Jun N-terminal kinase （JNK） signaling and analyzed their differentiation, proliferation, migration, and invasion by Western blotting, 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide analysis, and transwell assays. The Student＇s t-test was used to compare the differences between two groups. Results： Fstll deficiency attenuated phosphorylation of the ERK, p38, and JNK signaling in bleomycin-induced fibrotic lung tissue 14 days after injury （0.67 ± 0.05 vs. 1.22 ± 0.03, t = 14.92, P = 0.0001; 0.41 ± 0.01 vs. 1.15 ± 0.07; t = 11.19; P = 0.0004; and 0.41 ± 0.01 vs. 1.07± 0.07, t = 8.92, P = 0.0009; respectively）, compared with WT lungs at the same time and in primary lung fibroblasts （0.82 ± 0.01 vs. 1.01 ±0.04, t = 4.06, P = 0.0150; 1.04 ±0.03 vs. 1展开更多
文摘Background： Follistatin-like I （FSTL 1） is a novel profibrogenic factor that induces pulmonary fibrosis （PF） through the transforming growth factor-beta 1 （TGF-[B 1 ）/Smad signaling. Little is known about its effects on PF through the non-Smad signaling, like the mitogen-activated protein kinase （MAPK） pathway. Therefore, this study aimed to investigate the role ofFSTL 1 in PF through the MAPK signaling pathway and its mechanisms in lung fibrogenesis. Methods： PF was induced in Fstll~ and wild-type （WT） C57BL/6 mice with bleomycin. After 14 days, the mice were sacrificed, and lung tissues were stained with hematoxylin and eosin; the hydroxyproline content was measured to confirm PF. The mRNA and protein level of FSTLI and the change of MAPK phosphorylation were measured by quantitative polymerase chain reaction and Western blotting. The effect of Fst11 deficiency on fibroblasts differentiation was measured by Western blotting and cell immunofluorescence. MAPK signaling activation was measured by Western blotting in Fst11＋/ and WT fibroblasts treated with recombinant human FSTLI protein. We pretreated mouse lung fibroblast cells with inhibitors of the extracellular signal-regulated kinase （ERK）, p38, and Jun N-terminal kinase （JNK） signaling and analyzed their differentiation, proliferation, migration, and invasion by Western blotting, 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide analysis, and transwell assays. The Student＇s t-test was used to compare the differences between two groups. Results： Fstll deficiency attenuated phosphorylation of the ERK, p38, and JNK signaling in bleomycin-induced fibrotic lung tissue 14 days after injury （0.67 ± 0.05 vs. 1.22 ± 0.03, t = 14.92, P = 0.0001; 0.41 ± 0.01 vs. 1.15 ± 0.07; t = 11.19; P = 0.0004; and 0.41 ± 0.01 vs. 1.07± 0.07, t = 8.92, P = 0.0009; respectively）, compared with WT lungs at the same time and in primary lung fibroblasts （0.82 ± 0.01 vs. 1.01 ±0.04, t = 4.06, P = 0.0150; 1.04 ±0.03 vs. 1
