Tiotropium discontinuation in patients with early-stage COPD: a prospective observational cohort study

Background Tiotropium improves lung function and ameliorates the annual decline in forced expiratory volume in 1 s (FEV1) after bronchodilator use in patients with mild to moderate chronic obstructive pulmonary disease (COPD). However, whether these benefits persist in patients with early-stage COPD after tiotropium discontinuation is unknown. Methods In this prospective cohort observational follow-up study, patients who had completed the Tiotropium in Early-Stage COPD (Tie-COPD) trial were followed for a maximum of 3 years, continuing or discontinuing treatment according to their willingness. The outcomes measured were spirometry parameters, COPD exacerbations, COPD Assessment Test (CAT) scores, Clinical COPD Questionnaire (CCQ) scores, modified Medical Research Council (mMRC) scores and the use of respiratory medications. Results Out of 376 patients, 262 (126 in the post-placebo group and 136 in the post-tiotropium group) completed the maximum 3-year follow-up after the study medication was withdrawn. After discontinuation, the decrease in FEV1 and forced vital capacity (FVC) did not differ significantly between the two groups, and neither did their annual decline. In addition, the frequency of acute COPD exacerbations and the mMRC scores were similar between the two groups after medication withdrawal. Both the mean CAT and CCQ scores were significantly lower in the post-tiotropium group than in the post-placebo group (p<0.05 for all comparisons) at the 1-year follow-up after withdrawal, but they were not different at the next follow-up. Conclusion Withdrawal of tiotropium treatment in early-stage COPD resulted in difference reduction of both FEV1 and FVC, indicating that treatment should be continued

MiR-194-5p enhances the sensitivity of nonsmall-cell lung cancer to doxorubicin through targeted inhibition of hypoxia-inducible factor-1

Abstract Background Despite chemotherapy being a common treatment, an increase in chemoresistance over time is unavoidable. We therefore investigated the role of miR-194-5p in regulating chordoma cell behavior and examined the downstream effectors of miR-194-5p. Methods In this study, NSCLC cell lines A549 and H460 were cultured under hypoxic conditions for 1 week to induce drug resistance to doxorubicin (DOX). The connection between miR-194-5p and HIF-1 was revealed by reverse transcription and real-time polymerase chain reaction (RT-qPCR), western blot, and dual-luciferase assays. We used TUNEL staining and the CCK-8 test to assess the sensitivity of NSCLC cells to DOX. Results We found that hypoxia-induced NSCLC cells enhanced resistance to DOX. MiR-194-5p was substantially reduced, and HIF-1 was increased in hypoxia-induced drug-resistant NSCLC cells. Moreover, miR-194-5p successfully induced NSCLC cell apoptosis by directly inhibiting HIF-1, thereby enhancing DOX sensitivity. Conclusions MiR-194-5p enhanced the sensitivity of NSCLC cells to DOX by directly inhibiting HIF-1. This work provides insights into underlying treatments for drug-resistant NSCLC

PM2.5 promotes human bronchial smooth muscle cell migration via the sonic hedgehog signaling pathway

Abstract Background The contribution of airway remodeling in chronic obstructive pulmonary disease (COPD) has been well documented, with airway smooth muscle cell proliferation and migration playing a role in the remodeling process. Here, we aimed to verify the effects of fine particulate matter (PM2.5) on human bronchial smooth muscle cell (HBSMC) migration and to explore the underlying signaling pathways. Methods HBSMC apoptosis, proliferation and migration were measured using flow cytometry, cell counting and transwell migration assays, respectively. The role of the hedgehog pathway in cell migration was assessed by western blotting to measure the expression of Sonic hedgehog (Shh), Gli1 and Snail. Furthermore, siRNA was used to knock down Gli1 or Snail expression. Results PM2.5 induced HBSMC apoptosis in a dose-dependent manner, although certain concentrations of PM2.5 did not induce HBSMC proliferation or apoptosis. Interestingly, cell migration was stimulated by PM2.5 doses far below those that induced apoptosis. Additional experiments revealed that these PM2.5 doses enhanced the expression of Shh, Gli1 and Snail in HBSMCs. Furthermore, PM2.5-induced cell migration and protein expression were enhanced by recombinant Shh and attenuated by cyclopamine. Similar results were obtained by knocking down Gli1 or Snail. Conclusions These findings suggest that PM2.5, which may exert its effects through the Shh signaling pathway, is necessary for the migration of HBSMCs. These data define a novel role for PM2.5 in airway remodeling in COPD

Nicotine-Induced Airway Smooth Muscle Cell Proliferation Involves TRPC6-Dependent Calcium Influx Via α7 nAChR

Background/Aims: The proliferation of human bronchial smooth muscle cells (HBSMCs) is a key pathophysiological component of airway remodeling in chronic obstructive pulmonary disease (COPD) for which pharmacotherapy is limited, and only slight improvements in survival have been achieved in recent decades. Cigarette smoke is a well-recognized risk factor for COPD; however, the pathogenesis of cigarette smoke-induced COPD remains incompletely understood. This study aimed to investigate the mechanisms by which nicotine affects HBSMC proliferation. Methods: Cell viability was assessed with a CCK-8 assay. Proliferation was measured by cell counting and EdU immunostaining. Fluorescence calcium imaging was performed to measure intracellular Ca2+ concentration ([Ca2+]i). Results: The results showed that nicotine promotes HBSMC proliferation, which is accompanied by elevated store-operated calcium entry (SOCE), receptor-operated calcium entry (ROCE) and basal [Ca2+]i in HBSMCs. Moreover, we also confirmed that canonical transient receptor potential protein 6 (TRPC6) and α7 nicotinic acetylcholine receptor (α7 nAChR) are involved in nicotine-induced upregulation of cell proliferation. Furthermore, we verified that activation of the PI3K/Akt signaling pathway plays a pivotal role in nicotine-enhanced proliferation and calcium influx in HBSMCs. Inhibition of α7 nAChR significantly decreased Akt phosphorylation levels, and LY294002 inhibited the protein expression levels of TRPC6. Conclusion: Herein, these data provide compelling evidence that calcium entry via the α7 nAChR-PI3K/Akt-TRPC6 signaling pathway plays an important role in the physiological regulation of airway smooth muscle cell proliferation, representing an important target for augmenting airway remodeling

Self-gating in semiconductor electrocatalysis

The semiconductor-electrolyte interface dominates the behaviours of semiconductor electrocatalysis, which has been modelled as a Schottky-analogue junction according to classical electron transfer theories. However, this model cannot be used to explain the extremely high carrier accumulations in ultrathin semiconductor catalysis observed in our work. Inspired by the recently developed ion-controlled electronics, we revisit the semiconductor-electrolyte interface and unravel a universal self-gating phenomenon through microcell-based in situ electronic/electrochemical measurements to clarify the electronic-conduction modulation of semiconductors during the electrocatalytic reaction. We then demonstrate that the type of semiconductor catalyst strongly correlates with their electrocatalysis; that is, n-type semiconductor catalysts favour cathodic reactions such as the hydrogen evolution reaction, p-type ones prefer anodic reactions such as the oxygen evolution reaction and bipolar ones tend to perform both anodic and cathodic reactions. Our study provides new insight into the electronic origin of the semiconductor-electrolyte interface during electrocatalysis, paving the way for designing high-performance semiconductor catalysts.NRF (Natl Research Foundation, S’pore)ASTAR (Agency for Sci., Tech. and Research, S’pore)MOE (Min. of Education, S’pore)Accepted versio

Additional file 1: of PM2.5 promotes human bronchial smooth muscle cell migration via the sonic hedgehog signaling pathway

Figure S1A–D. Effects of PM2.5 on the migration of HBFs. (A) HBF migration in the control group. (B) Effects of TAPM2.5 on HBF migration. (C) Effects of WSPM2.5 on HBF migration. (D) Quantitative analysis of HBF migration. *, P < 0.05 compared with the control. (TIFF 9170 kb