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Aim of the Study: Obstructive sleep apnea (OSA) is a common disease associated with significant morbidity and mortality. Sleep quality is an important issue; some patients with acute lung injury (ALI) have underlying OSA. However, the potential influences of OSA on ALI have not been reported until now. In this study, we evaluated the impact of preceding intermittent hypoxia (IH), a typical characteristic of OSA, on lipopolysaccharide (LPS)-induced ALI in a mouse model., Methods: C57BL/6J mice were randomly divided into four groups: room air-control (RA-CTL), intermittent hypoxia-control (IH-CTL), room air-lipopolysaccharide (RA-LPS), and intermittent hypoxia-lipopolysaccharide (IH-LPS) groups. The mice were exposed to RA or IH (20 cycles/h, FiO 2 nadir 7 ± 0.5%, 8 h/day) for 30 days. The LPS groups received intratracheal LPS on day 28., Results: The IH-LPS group tended to exhibit more severe inflammation, fibrosis, and oxidative stress compared to the other groups, including the RA-LPS group. Total cell, neutrophil, and eosinophil counts in bronchoalveolar lavage fluid increased significantly in the IH-LPS group compared to the RA-LPS group. Compared to the RA-LPS group, the hydroxyproline level increased significantly in the IH-LPS group. In addition, the IH-LPS group exhibited significantly more terminal deoxynucleotidyl transferase dUTP nick end labeled-positive cells compared to the RA-LPS group., Conclusions: We found that prior IH may negatively impact LPS-induced ALI in a mouse model. This result suggests that ALI in patients with OSA may be more of a concern. Further research into the mechanisms underlying the effects of IH on ALI is needed.

Purpose/Aim of the study: Prolonged exposure to hyperoxia can cause injury to normal lung tissue. However, patients with acute hypoxic respiratory failure are frequently exposed to very high oxygen levels. This study investigated the effects of long term normobaric hyperoxia exposure in a mouse model of acute severe lung injury (SLI). Meterials and Methods: C57BL/6J mice were injected intratracheally with lipopolysaccharide (LPS, 4 mg/kg) to induce acute lung injury. After 2 h, mice were divided into two groups, and then exposed to room air or hyperoxic conditions for 48 h. Animals in the hyperoxia group were placed within their cages in a Plexiglass chamber with an atmosphere of 95% O 2 maintained constant using an oxygen analyzer. After exposure to normoxia (N) or hyperoxia (H) for 48 h, the left lungs were collected for tissue paraffin block or oxidative stress assay. One lobe of the right lung was collected for lung/body weight ratio. The lung injury score and the mean linear intercept were evaluated in hematoxylin and eosin -stained lungs. The biochemical tests were performed by using ELISA assay. Results: Lung injury scoring, lung/body weight, and mean linear intercept were not significantly different between the N + LPS (NLPS) and H + LPS (HLPS) groups. Similar trends were observed in hydroxyproline and transforming growth factor-β (TGF-β) levels. Total cell and neutrophil counts in bronchoalveolar lavage fluid showed no significant differences between NLPS and HLPS groups. Histological analyses demonstrated more severe lung injury and fibrosis in the NLPS group than in the HLPS group. In addition, interleukin (IL)-1β was significantly decreased in the HLPS group compared to the NLPS group. Other inflammatory cytokines, such as tumor necrosis factor-α (TNF-α) and IL-6, showed similar trends. The malondialdehyde (MDA) level was significantly lower in the HLPS group than in the NLPS group. Conclusions: Exposure to hyperoxia did not augment lung injury in the LPS-induced lung injury model, and some indicators even showed better outcomes. These results suggest that long-term high-oxygen therapy in patients with SLI has low risk of lung injury.

Purpose: The aim of the present study was to demonstrate the role of insulin-like growth factor-1 receptor (IGF-1R) tyrosine kinase inhibitors (TKIs) in IGF-1R expressed epidermal growth factor receptor (EGFR) mutant cells., Materials and Methods: Human lung adenocarcinoma PC9, HCC827, and H1975 cells were exposed to a combination of IGF-1, gefitinib, or linsitinib. Cell viability was assessed by the MTT assay. The expression of EGFR, IGF-1R, AKT, extracellular regulated kinases 1 and 2 (ERK1/2), cleaved poly ADP ribose polymerase (PARP), cleaved caspase 3, and hypoxia-inducible factor (HIF)-1α were measured by Western blot. The concentrations of vascular endothelial growth factor (VEGF) were measured using an enzyme-linked immunosorbent assay kit., Results: Cell growth in PC9 and HCC827 cells was synergistically suppressed by co-treatment with gefitinib and linsitinib. Gefitinib did not affect H1975 cell growth; however, linsitinib suppressed cell proliferation. Co-treatment with gefitinib and linsitinib inhibited pAKT and pERK, and linsitinib treatment profoundly reduced IGF-1-induced pIGF-1R expression in PC9 and HCC827 cells. Dual treatment increased the number of Annexin-V-positive HCC827 and H1975 cells, and expression of cleaved caspase 3 and cleaved PARP increased in H1975 cells following linsitinib treatment. Gefitinib inhibited HIF-1α and VEGF expression in HCC827 cells, and linsitinib inhibited VEGF production in H1975 cells., Conclusion: IGF-1R TKIs had modest anti-tumor efficacy and their effects were explained by blocking the EGFR and IGF-1R pathway in IGF-1R expressing EGFR-sensitive cells. IGF-1R TKI had pro-apoptotic activity and inhibited cellular growth in EGFR-resistant cells.

Purpose: Statins are known to have pleiotropic effects that induce cell death in certain cancer cells. BIM is a member of the bcl-2 gene family, which promotes apoptotic cell death. This study investigated the hypothesis that simvastatin has pro-apoptotic effects in epidermal growth factor receptor (EGFR)-mutated lung cancer cell lines via the upregulation of the expression of the BIM protein., Materials and Methods: The cytotoxic effects of simvastatin on gefitinib-sensitive (HCC827, E716-A750del) and -resistant (H1975, T790M + L858R) nonsmall cell lung cancer (NSCLC) cells were compared. Cell proliferation and expression of apoptosis-related and EGFR downstream signaling proteins were evaluated. Expression of BIM was compared in H1975 cells after treatment with simvastatin or gefitinib. SiRNA-mediated BIM depletion was performed to confirm whether the cytotoxicity of simvastatin was mediated by the expression of BIM., Results: H1975 cells showed significantly reduced viability compared with HCC827 cells after treatment with simvastatin (2 μM) for 48 hours. In simvastatin-treated H1975 cells, expression of pro-apoptotic proteins was increased and the phosphorylation of ERK 1/2 (p-ERK 1/2) was reduced. Expression of BIM was suppressed by gefitinib (1 μM) treatment in H1975 cells, but it was significantly increased by treatment with simvastatin. BIM depletion by siRNA transfection enhanced the viability of H1975 cells that received simvastatin treatment and increased their expression of anti-apoptotic proteins., Conclusions: Simvastatin restored the expression of BIM to induce apoptotic cell death in NSCLC cells harboring an EGFR-resistant mutation. Our study suggests the potential utility of simvastatin as a BIM-targeted treatment for NSCLC.

Purpose: Cigarette smoking increases chronic airway inflammation, oxidative stress, and epithelial mesenchymal transition (EMT), which may result in chronic obstructive pulmonary disease (COPD) and tumor growth in the lung. Phosphodiesterase 4 (PDE4) inhibitors are known to reduce inflammation, and they have recently been introduced for the treatment of COPD. We assessed the impact of rolipram, a selective PDE4 inhibitor, on chemoprevention in benzo(a)pyrene-induced lung cancer in mice., Materials and Methods: Female A/J mice were given a single dose of benzo(a)pyrene. Intraperitoneal administration of rolipram began 2 weeks post-carcinogen treatment and continued tri-weekly for 28 weeks. Tumor load was determined by averaging the total tumor volume in each group., Results: Benzo(a)pyrene induced an average tumor size of 10.4 ± 1.7 tumors per mouse, with an average tumor load of 25.9 ± 3.8 mm(3). Rolipram significantly decreased tumor number, by 45.1%, and tumor load, by 52.9%, compared with the benzo(a)pyrene group. Ki67 staining was reduced in rolipram-treated mice compared with benzo(a)pyrene-treated mice. The increased expression of EMT markers caused by benzo(a)pyrene was inhibited by rolipram. Rolipram significantly attenuated NF-κB and Nrf2 expression in benzo(a)pyrene-induced lung cancer tissues., Conclusions: In vivo experiments in the benzo(a)pyrene-induced model of lung cancer show that PDE4 inhibition significant inhibits lung carcinogenesis. Our results provide evidence that PDE4 inhibitors may be suitable for the prevention of the lung cancer in high-risk groups, for example, heavy smokers and patients with COPD.

Although neutropenia recovery is associated with deterioration of preexisting acute lung injury (ALI), there are few reports of the preventive strategies. Statins have been found to attenuate inflammatory responses in murine models of lipopolysaccharide (LPS)-induced ALI. The aim of this study was to determine whether pravastatin could attenuate ALI during neutropenia recovery in mice. Cyclophosphamide was administered to mice to induce neutropenia. Mice were given intratracheal LPS 7 days after cyclophosphamide administration, after which pravastatin was administered by intraperitoneal injection. In order to study the effects of pravastatin, mice were killed on day 5. Pravastatin attenuated the pulmonary edema and histopathological changes of LPS-induced lung injury. The accumulation of neutrophils and the concentrations of TNF-α, IL-1β, IL-6, and MPO in BAL fluids were also effectively inhibited by pravastatin. The expression levels of Toll-like receptor 4, nuclear factor kappa B, tumor growth factor-β and matrix metalloproteinase-9 were significantly reduced by pravastatin. Taken together, pravastatin significantly attenuated LPS-induced ALI during neutropenia recovery. These results provide evidence for the potential of pravastatin in the treatment of ALI during neutropenia recovery.