{'fraction_non_alphanumeric': 0.04010416666666667, 'fraction_numerical': 0.018229166666666668, 'mean_word_length': 5.117834394904459, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
HIF-1α Contributes to the Progression of Chronic Obstructive Pulmonary Disease

Background Hypoxia-inducible factor-1α (HIF-1α) plays an important regulatory role in inflammatory and hypoxic diseases. Higher HIF-1α level was found in lungs of chronic obstructive pulmonary disease (COPD) patients, however, its role in cigarette smoke (CS)-induced COPD has not been fully studied. Digoxin has been showed to inhibit HIF-1α translation and block HIF-1α activity and thus is often used as the HIF-1α inhibitor. Therefore, in the present study, we chose digoxin as the inhibitor to investigate whether HIF-1α contributes to the progression of COPD and possible mechanism. Methods CS-exposed mice were intragastrically treated with different doses of digoxin, and COPD-associated phenotypes such as pathological changes in lungs, inflammation, lung function and mucus secretion in airways were evaluated. Meanwhile, CSE-treated A549 cells were administrated with digoxin or S7959. Moreover, EMT-associated markers together with HIF-1α\TGF-β1\Smad3 signaling pathway were detected both in vivo and in vitro. Results The level of HIF-1α was significantly increased in lungs of COPD mice and CSE-exposed A549 cells, which was markedly suppressed by digoxin. Moreover, digoxin inhibited CS-induced inflammatory responses, lung function decline, and mucus hyper-secretion in COPD mouse model. In in vitro studies, digoxin decreased CSE-induced pro-inflammatory cytokine release. Importantly, CS-induced or CSE-induced EMT and up-regulation of HIF-1α/TGF-β1/Smad pathway was inhibited by digoxin. Additionally, S7959 mitigated CSE-induced EMT in A549 cells. Conclusions Digoxin can protect CS-induced COPD and prevent CS-induced EMT possibly through HIF-1α/TGF-β1/Smad3 signaling pathway. This study suggests HIF1-α could be a potential intervention target for COPD prevention and treatment, especially for EMT in CS-induced COPD.