Soluble epoxide hydrolase inhibitor AUDA decreases bleomycin-induced pulmonary toxicity in mice by inhibiting the p38/Smad3 pathways.

Bleomycin (BLM) has potent tumor cell-killing properties that have given it an important place in cancer chemotherapy, but pulmonary toxicity is its major adverse effect. Soluble epoxide hydrolase (sEH) inhibitors have been reported to have protective effects in fibrosis models, but the effects of AUDA, an sEH inhibitor of BLM-induced pulmonary toxicity and fibrosis, remain to be researched. In this study, we assessed the effects of AUDA on the BLM-induced pulmonary fibrosis in a mouse model, and transforming growth factor (TGF)-β1-induced epithelial proliferation and epithelial-mesenchymal transition (EMT) in vitro by monitoring changes in pulmonary function, inflammatory response, fibrotic remodeling, and signaling pathways. AUDA was administered by intragastric administration (i.g) daily for three weeks, starting at seven days after intratracheal instillation of BLM. All examinations were performed 24h after the last i.g. In vivo, AUDA significantly improved BLM-induced decline in lung function and body weight, and inhibited inflammatory cell accumulation and the mRNA and protein expression of interleukin (IL)-1β, TGF-β1, and matrix metalloproteinase 9 (MMP-9) in lung tissue. Moreover, AUDA attenuated BLM-induced deposition of collagen fibers, destruction of alveolar structures, and pulmonary parenchyma. Additionally, AUDA regulated the expression of α-smooth muscle actin (α-SMA) and E-cadherin by inhibiting the Smad3/p38 signaling pathway. In vitro, AUDA significantly inhibited TGF-β1-induced epithelial cells and fibroblast proliferation, reduced sEH expression and α-SMA expression, and increased epoxyeicosatrienoic acid (EET) levels and E-cadherin expression in epithelial cells. These effects were blocked by AUDA by downregulating the Smad3 and p38 signaling pathways. Taken together, these data indicate that treatment with sEH inhibitors may improve BLM-induced pulmonary toxicity.

Dong XW ，Jia YL ，Ge LT ，Jiang B ，Jiang JX ，Shen J ，Jin YC ，Guan Y ，Sun Y ，Xie QM ... -  《-》

Inhibition of soluble epoxide hydrolase attenuates airway remodeling in a chronic asthma model.

Airway remodeling in asthma is difficult to treat because of its complex pathophysiology that involves proinflammatory cytokines, as well as the arachidonic acid cytochrome P-450 (CYP) pathway; however, it has received little attention. In this study, we assessed the efficacy of a soluble epoxide hydrolase (sEH) on airway remodeling in a mouse model of chronic asthma. The expression of sEH and CYP2J2 and the level of 14,15-epoxyeicosatrienoic acid (14,15-EET), airway remodeling and hyperresponsiveness (AHR) were analyzed to determine the level of sEH inhibition. AUDA, a sEH inhibitor, was given daily for 9 weeks orally, which significantly increased the level of 14,15-EET by inhibiting the expression of sEH and increasing the expression of CYP2J2 in lung tissues. The inhibition of sEH reduced the expression of remodeling-related molecular markers, such as interleukin (IL)-13, IL-17, matrix metalloproteinase 9, N-cadherin, α-smooth muscle actin (α-SMA), S100A4, Twist, epithelial goblet cell metaplasia, and collagen deposition in bronchoalveolar lavage fluid (BAL fluid) and lung tissues. Moreover, remodeling-related eosinophil accumulation in the BAL fluid and infiltration into the lung tissue were improved by AUDA. Finally, AUDA alleviated AHR, which is a functional indicator of airway remodeling. The effect of AUDA on airway remodeling was related to the downregulation of extracellular-regulated protein kinases (Erk1/2), c-Jun N-terminal kinases (JNK) and signal transducer and activator of transcription 3 (STAT3). To our knowledge, this is the first report to demonstrate that inhibition of sEH exerts significant protective effects on airway remodeling in asthma.

Jiang JX ，Guan Y ，Shen HJ ，Jia YL ，Shen J ，Zhang LH ，Liu Q ，Zhu YL ，Xie QM ... -  《-》

Soluble epoxide hydrolase inhibition ameliorates proteinuria-induced epithelial-mesenchymal transition by regulating the PI3K-Akt-GSK-3β signaling pathway.

Soluble epoxide hydrolase (sEH) plays an essential role in chronic kidney disease by hydrolyzing renoprotective epoxyeicosatrienoic acids to the corresponding inactive dihydroxyeicosatrienoic acids. However, there have been few mechanistic studies elucidating the role of sEH in epithelial-mesenchymal transition (EMT). The present study investigated, in vitro and in vivo, the role of sEH in proteinuria-induced renal tubular EMT and the underlying signaling pathway. We report that urinary protein (UP) induced EMT in cultured NRK-52E cells, as evidenced by decreased E-cadherin expression, increased alpha-smooth muscle actin (α-SMA) expression, and the morphological conversion to a myofibroblast-like phenotype. UP incubation also resulted in upregulated sEH, activated phosphatidylinositol 3-kinase (PI3K)-protein kinase B (PKB/Akt) signaling and increased phosphorylated glycogen synthase kinase-3β (GSK-3β). The PI3K inhibitor LY-294002 inhibited phosphorylation of Akt and GSK-3β as well as blocking EMT. Importantly, pharmacological inhibition of sEH with 12-(3-adamantan-1-yl- ureido)-dodecanoic acid (AUDA) markedly suppressed PI3K-Akt activation and GSK-3β phosphorylation. EMT associated E-cadherin suppression, α-SMA elevation and phenotypic transition were also attenuated by AUDA. Furthermore, in rats with chronic proteinuric renal disease, AUDA treatment inhibited PI3K-Akt activation and GSK-3β phosphorylation, while attenuating levels of EMT markers. Overall, our findings suggest that sEH inhibition ameliorates proteinuria-induced renal tubular EMT by regulating the PI3K-Akt-GSK-3β signaling pathway. Targeting sEH might be a potential strategy for the treatment of EMT and renal fibrosis.

Liang Y ，Jing Z ，Deng H ，Li Z ，Zhuang Z ，Wang S ，Wang Y ... -  《-》

Grape seed extract ameliorates bleomycin-induced mouse pulmonary fibrosis.

Pulmonary fibrosis is common in a variety of inflammatory lung diseases, such as interstitial pneumonia, chronic obstructive pulmonary disease, and silicosis. There is currently no effective clinical drug treatment. It has been reported that grape seed extracts (GSE) has extensive pharmacological effects with minimal toxicity. Although it has been found that GSE can improve the lung collagen deposition and fibrosis pathology induced by bleomycin in rat, its effects on pulmonary function, inflammation, growth factors, matrix metalloproteinases and epithelial-mesenchymal transition remain to be researched. In the present study, we studied whether GSE provided protection against bleomycin (BLM)-induced mouse pulmonary fibrosis. ICR strain mice were treated with BLM in order to establish pulmonary fibrosis models. GSE was given daily via intragastric administration for three weeks starting at one day after intratracheal instillation. GSE at 50 or 100mg/kg significantly reduced BLM-induced inflammatory cells infiltration, proinflammatory factor protein expression, and hydroxyproline in lung tissues, and improved pulmonary function in mice. Additionally, treatment with GSE also significantly impaired BLM-induced increases in lung fibrotic marker expression (collagen type I alpha 1 and fibronectin 1) and decreases in an anti-fibrotic marker (E-cadherin). Further investigation indicated that the possible molecular targets of GSE are matrix metalloproteinases-9 (MMP-9) and TGF-β1, given that treatment with GSE significantly prevented BLM-induced increases in MMP-9 and TGF-β1 expression in the lungs. Together, these results suggest that supplementation with GSE may improve the quality of life of lung fibrosis patients by inhibiting MMP-9 and TGF-β1 expression in the lungs.

Liu Q ，Jiang JX ，Liu YN ，Ge LT ，Guan Y ，Zhao W ，Jia YL ，Dong XW ，Sun Y ，Xie QM ... -  《-》

Ajulemic acid exerts potent anti-fibrotic effect during the fibrogenic phase of bleomycin lung.

Lucattelli M ，Fineschi S ，Selvi E ，Garcia Gonzalez E ，Bartalesi B ，De Cunto G ，Lorenzini S ，Galeazzi M ，Lungarella G ... -  《RESPIRATORY RESEARCH》