Hydrogen inhalation attenuated bleomycin-induced pulmonary fibrosis by inhibiting transforming growth factor-β1 and relevant oxidative stress and epithelial-to-mesenchymal transition.

• What is the central question of this study? The aim was to explore the effects and underlying mechanisms of H2 on bleomycin-induced pulmonary fibrosis. • What are the main findings and its importance? Our results indicate that, in bleomycin-induced pulmonary fibrosis, H2 inhalation attenuated oxidative stress and reversed the pulmonary epithelial-to-mesenchymal transition process by reducing reactive oxygen species production and inhibiting the expression of transforming growth factor-β1, α-smooth muscle actin and collagen I to improve fibrotic injury and exert anti-fibrogenic effects. Thus, H2 inhalation has promising therapeutic potential as a useful adjuvant treatment for patients with idiopathic pulmonary fibrosis, which deserves further study and evaluation. Hydrogen (H2 ) can protect against tissue damage. The effect of H2 inhalation therapy on the pathogenesis of pulmonary fibrosis remains unknown. This study was designed to explore the effects and underlying mechanisms of H2 inhalation on bleomycin (BLM)-induced pulmonary fibrosis. A rat model of pulmonary fibrosis was established with BLM. Rats were randomly divided into control and H2 inhalation groups. Haematoxylin and Eosin staining and Mason's Trichrome staining were performed to evaluate pulmonary fibrosis injury, inflammatory cell infiltration, structural disorder and collagen deposition. qRT-PCR and western blot assays were used to determine the expression of TNF-α, TGF-β1, α-SMA, E-cadherin, N-cadherin, vimentin, VEGF and collagen type I at both mRNA and protein levels. The contents of reactive oxygen species, TGF-β1, TNF-α, malondialdehyde and hydroxyproline were determined with biochemical test kits or ELISA kits. Bleomycin-stimulated rats exhibited typical symptoms of pulmonary fibrosis, which featured an increase in collagen deposition, alveolitis, fibrosis and parenchymal structural disorder in the lung. However, BLM-induced oxidative stress was attenuated by H2 inhalation therapy, which reduced the contents of reactive oxygen species, malondialdehyde and hydroxyproline, enhanced the activity of glutathione peroxidase and decreased the expression of TGF-β1 and TNF-α. In addition, H2 inhalation also inhibited BLM-induced epithelial-to-mesenchymal transition by inhibiting TGF-β1, increasing the expression level of the epithelial cell marker E-cadherin, and decreasing the expression level of the mesenchymal cell marker vimentin in a time-dependent manner. In addition, H2 inhalation downregulated α-SMA expression and suppressed collagen I generation, exerting anti-fibrogenic effects. Hydrogen inhalation therapy attenuates BLM-induced pulmonary fibrosis by inhibiting TGF-β1, relevant oxidative stress and epithelial-to-mesenchymal transition.

Gao L ，Jiang D ，Geng J ，Dong R ，Dai H ... -  《-》

Mangiferin attenuates bleomycin-induced pulmonary fibrosis in mice through inhibiting TLR4/p65 and TGF-β1/Smad2/3 pathway.

Investigating the antipulmonary fibrosis effect of mangiferin from Mangifera indica and the possible molecular mechanism. In vivo, bleomycin (BLM)-induced pulmonary fibrosis experimental model was used for evaluating antipulmonary fibrosis effect of mangiferin. Histopathologic examination and collagen deposition were investigated by HE and Masson staining as well as detecting the content of hydroxyproline. The expression of transforming growth factor-β1 (TGF-β1), α-smooth muscle actin (α-SMA), TLR4 and p-P65 in lung tissue was analysed through immunofluorescence. Leucocytes and inflammatory cytokines including IL-1β, IL-6, TNF-α and MCP-1 in bronchoalveolar lavage fluid were detected by cell counting and enzyme-linked immunosorbent assay. In vitro, TGF-β1-induced A549 epithelial-mesenchymal transition (EMT) cell model was used for investigating the possible molecular mechanism. Reactive oxygen species (ROS) generation was detected by DCFH-DA assay. Expression of all proteins was examined by Western blot. Oral administration of mangiferin could attenuate the severity of BLM-induced pulmonary fibrosis through increasing the survival rate, improving histopathological lesion and body weight loss as well as decreasing pulmonary index visibly. Pulmonary hydroxyproline content, TGF-β1, and α-SMA levels were reduced significantly. The molecular mechanism of mangiferin for inhibiting pulmonary fibrosis is that it could obviously inhibit the occurrence of inflammation and the secretion of inflammatory cytokine through inhibiting activation of TLR4 and phosphorylation of p65. Meanwhile, EMT process was suppressed obviously by mangiferin through blocking the phosphorylation of Smad2/3 and reducing MMP-9 expression. Besides, mangiferin could significantly inhibit the process of oxidant stress through downregulating the intracellular ROS generation. Mangiferin attenuates BLM-induced pulmonary fibrosis in mice through inhibiting TLR4/p65 and TGF-β1/Smad2/3 pathway.

Jia L ，Sun P ，Gao H ，Shen J ，Gao Y ，Meng C ，Fu S ，Yao H ，Zhang G ... -  《-》

Sulforaphane attenuates pulmonary fibrosis by inhibiting the epithelial-mesenchymal transition.

Kyung SY ，Kim DY ，Yoon JY ，Son ES ，Kim YJ ，Park JW ，Jeong SH ... -  《BMC Pharmacology & Toxicology》

Tanshinone IIA ameliorates bleomycin-induced pulmonary fibrosis and inhibits transforming growth factor-beta-β-dependent epithelial to mesenchymal transition.

Epithelial to mesenchymal transition (EMT) of alveolar epithelial cells occurs in lung fibrotic diseases. Tanshinone IIA (Tan IIA) has been reported to exert anti-inflammatory effects in pulmonary fibrosis. Nonetheless, whether Tan IIA affects lung fibrosis-related EMT remains unknown and requires for further investigations. A single intratracheal instillation of saline containing bleomycin (BLM; 5 mg/kg body weight) was performed to induce pulmonary fibrosis in Sprague-Dawley rats. Rats receiving an instillation of equivoluminal normal saline served as controls. Then, these rats were given a daily intraperitoneal administration of Tan IIA (15 mg/kg body weight) for 28 d before sacrifice. In vitro, recombinant transforming growth factor-beta 1 (TGF-β1; 10 ng/mL) was used to treat human alveolar epithelial A549 cells for 48 h. Tan IIA (10 μM) or control DMSO was used to pretreat cells for 2 h before TGF-β1 stimulation. Rat lung tissue samples and A549 cells were then subjected to further assessments. Tan IIA was noted to alleviate BLM-induced pulmonary collagen deposition and macrophage infiltration in rats. Epithelial-cadherin expression was decreased after BLM stimulation, whereas α-smooth muscle actin, fibronectin, and vimentin were increased. These expression alterations were partially reversed by Tan IIA. Moreover, Tan IIA suppressed BLM-induced increases in TGF-β1, phosphorylated Smad-2, and -3 in rats. Additionally, pretreatment of Tan IIA inhibited TGF-β1-triggered EMT, reduced collagen Ⅰ production, and blocked TGF-β signal transduction in A549 cells. Our research suggests that Tan IIA mitigates BLM-induced pulmonary fibrosis and suppresses TGF-β-dependent EMT of lung alveolar epithelial cells.

Tang H ，He H ，Ji H ，Gao L ，Mao J ，Liu J ，Lin H ，Wu T ... -  《-》

[Aqueous extract of Epimedium sagittatum mitigates pulmonary fibrosis in mice].

Wang R ，Hou FY ，Zeng MN ，Zhang BB ，Zhang QQ ，Xie SS ，Feng WS ，Zheng XK ... -  《-》