Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal disease with no effective treatment. The epithelial-mesenchymal transition (EMT) is a critical stage during the development of fibrosis. To assess the effect of sulforaphane (SFN) on the EMT and fibrosis using an in vitro transforming growth factor (TGF)-β1-induced model and an in vivo bleomycin (BLM)-induced model. In vitro studies, cell viability, and cytotoxicity were measured using a Cell Counting Kit-8. The functional TGF-β1-induced EMT and fibrosis were assessed using western blotting and a quantitative real-time polymerase chain reaction. The lungs were analyzed histopathologically in vivo using hematoxylin and eosin and Masson’s trichrome staining. The BLM-induced fibrosis was characterized by western blotting and immunohistochemical analyses for fibronectin, TGF-β1, E-cadherin (E-cad), and α-smooth muscle actin (SMA) in lung tissues. SFN reversed mesenchymal-like changes induced by TGF-β1 and restored cells to their epithelial-like morphology. The results confirmed that the expression of the epithelial marker, E-cadherin, increased after SFN treatment, while expression of the mesenchymal markers, N-cadherin, vimentin, and α-SMA decreased in A549 cells after SFN treatment. In addition, SFN inhibited TGF-β1-induced mRNA expression of the EMT-related transcription factors, Slug, Snail, and Twist. The SFN treatment attenuated TGF-β1-induced expression of fibrosis-related proteins, such as fibronection, collagen I, collagen IV, and α-SMA in MRC-5 cells. Furthermore, SFN reduced the TGF-β1-induced phosphorylation of SMAD2/3 protein in A549 cells and MRC-5 cells. BLM induced fibrosis in mouse lungs that was also attenuated by SFN treatment, and SFN treatment decreased BLM-induced fibronectin expression, TGF-β1 expression, and the levels of collagen I in the lungs of mice. SFN showed a significant anti-fibrotic effect in TGF-β-treated cell lines and BLM-induced fibrosis in mice. These findings showed that SFN has anti-fibrotic activity that may be considered in the treatment of IPF.

Interleukin-8 (IL-8) is a potent chemo-attractant cytokine responsible for neutrophil infiltration in lungs with idiopathic pulmonary fibrosis (IPF). The IL-8 protein and mRNA expression are increased in the lung with IPF. We evaluated the effect of single nucleotide polymorphisms (SNPs) of the IL-8 gene on the risk of IPF. One promoter (rs4073T>A) and two intronic SNPs (rs2227307T>G and rs2227306C>T) of the IL-8 genes were genotyped in 237 subjects with IPF and 456 normal controls. Logistic regression analysis was applied to evaluate the association of these SNPs with IPF. IL-8 in BAL fluids was measured using a quantitative sandwich enzyme immunoassay, and promoter activity was assessed using the luciferase reporter assay. The minor allele frequencies of rs4073T>A and rs2227307T>G were significantly lower in the 162 subjects with surgical biopsy-proven IPF and 75 subjects with clinical IPF compared with normal controls in the recessive model (OR = 0.46 and 0.48, p = 0.006 and 0.007, respectively). The IL-8 protein concentration in BAL fluids significantly increased in 24 subjects with IPF compared with 14 controls (p = 0.009). Nine IPF subjects homozygous for the rs4073 T>A common allele exhibited higher levels of the IL-8 protein compared with six subjects homozygous for the minor allele (p = 0.024). The luciferase activity of the rs4073T>A common allele was significantly higher than that of the rs4073T>A minor allele (p = 0.002). The common allele of a promoter SNP, rs4073T>A, may increase susceptibility to the development of IPF via up-regulation of IL-8.

Epithelial–mesenchymal transition (EMT), a process by which epithelial cells undergo a phenotypic conversion that leads to myofibroblast formation, plays a crucial role in the progression of idiopathic pulmonary fibrosis (IPF). Recently, it was revealed that hypoxia promotes alveolar EMT and that histone deacetylases (HDACs) are abnormally overexpressed in the lung tissues of IPF patients. In this study, we showed that HDAC3 regulated alveolar EMT markers via the AKT pathway during hypoxia and that inhibition of HDAC3 expression by small interfering RNA (siRNA) decreased the migration ability and invasiveness of diseased human lung fibroblasts. Furthermore, we found that HDAC3 enhanced the migratory and invasive properties of fibroblasts by positively affecting the EMT process, which in turn was affected by the increased and decreased levels of microRNA (miR)-224 and Forkhead Box A1 (FOXA1), respectively. Lastly, we found this mechanism to be valid in an in vivo system; HDAC3 siRNA administration inhibited bleomycin-induced pulmonary fibrosis in mice. Thus, it is reasonable to suggest that HDAC3 may accelerate pulmonary fibrosis progression under hypoxic conditions by enhancing EMT in alveolar cells through the regulation of miR-224 and FOXA1. This entire process, we believe, offers a novel therapeutic approach for pulmonary fibrosis.

Coix lacryma-jobi var. ma-yuen (Rom.Caill.) Stapf has been used in China as an herbal medicine. Many studies of this plant have reported anti-proliferative and apoptotic activities on human cancer cell lines. Therefore, this study of the anti-metastatic effect of Coix lacryma-jobi var. ma-yuen Stapf sprout extract (CLSE) in colorectal cancer cells may provide a scientific basis for exploring anti-cancer effects of edible crops. To evaluate the effect of CLSE on cell proliferation and signaling, we performed a Cell Counting Kit-8 (CCK-8) assay in HCT116 cells and used western blot analysis. Furthermore, scratch-wound healing, transwell migration, matrigel invasion, and adhesion assays were conducted to elucidate the anti-metastatic effects of CLSE under hypoxic conditions in colon cancer cells. First, CLSE decreased deferoxamine (DFO)-induced migration of colon cancer cells by 87%, and blocked colon cancer cell migration by 80% compared with hypoxia control cells. Second, CLSE treatment resulted in a 54% reduction in hypoxia-induced invasiveness of colon cancer cells, and 50% inhibition of adhesive potency through inactivation of the extracellular signal-regulated kinase (ERK) 1/2 and protein kinase b (AKT) pathways. Third, conditioned medium collected from CLSE-treated HCT116 cells suppressed tube formation of human umbilical vein endothelial cells (HUVECs) by 91%. CLSE inhibited migration, invasion, and adhesion of colon cancer cells and tube formation by HUVECs via repression of the ERK1/2 and AKT pathways under hypoxic conditions. Therefore, CLSE may be used to treat patients with colon cancer.