ABSTRACT
To explore the protective mechanism of simvastatin in acute lung injury (ALI), the lipopolysaccharide (LPS) induced (5â¯mg/kg) ALI rat model was used to examine the effects of simvastatin. Following simvastatin treatment, the histopathological evaluation of lung tissues was made using hematoxylin and eosin (H&E) staining. Also, myeloperoxidase (MPO) activity and the levels of tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1ß), and IL-10 were determined by ELISA. Blood gas analyses of arterial blood samples were performed to assess the pulmonary gas exchange. Moreover, the neutrophil count and total protein content were determined in the bronchoalveolar lavage (BAL) fluid. The ratio of wet lung to dry lung (W/D) and the alveolar fluid clearance (AFC) were calculated to estimate the severity of edema. Lastly, the levels of A2BAR, CFTR, claudin4, and claudin18 were also measured by qRT-PCR and Western blotting. Simvastatin treatment, in a dose-related manner, markedly improved the lung histological injury and decreased the levels of TNF-α, IL-1ß, and increased IL-10 in LPS induced ALI. Also, pulmonary neutrophil count was alleviated. Besides, a decreased ratio of W/D lung also confirmed the simvastatin intervention. Notably, simvastatin reduced the levels of A2BAR, CFTR, and claudin18 but upregulated claudin4 in lung tissues. Additionally, treatment with PSB1115, an antagonist of A2BAR, countered the protective effect of simvastatin in ALI. Our study demonstrates that simvastatin has a protective effect against LPS-induced ALI by activating A2BAR and should be exploited as a novel therapeutic target for the treatment of ALI.
Subject(s)
Acute Lung Injury/prevention & control , Adenosine A2 Receptor Agonists/pharmacology , Lung/drug effects , Receptor, Adenosine A2B/drug effects , Simvastatin/pharmacology , Acute Lung Injury/chemically induced , Acute Lung Injury/metabolism , Acute Lung Injury/pathology , Animals , Claudin-4/metabolism , Claudins/metabolism , Cystic Fibrosis Transmembrane Conductance Regulator/metabolism , Cytokines/metabolism , Disease Models, Animal , Inflammation Mediators/metabolism , Lipopolysaccharides , Lung/metabolism , Lung/pathology , Male , Neutrophil Infiltration/drug effects , Pulmonary Edema/chemically induced , Pulmonary Edema/metabolism , Pulmonary Edema/pathology , Pulmonary Edema/prevention & control , Rats, Sprague-Dawley , Receptor, Adenosine A2B/metabolism , Signal TransductionABSTRACT
BACKGROUND: Molecular targeted therapy for non-small cell lung carcinoma (NSCLC) is restricted due to resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs). This study evaluated the effects of dual targeting of MEK and PI3K in human EGFR-TKI resistant NSCLC cell lines. METHODS: EGFR-TKI resistant NSCLC cell lines H1975, H460, and A549, with different mutation and amplification status in EGFR, K-RAS, PIK3CA, and MET genes, were treated with a MEK162 (MEK inhibitor) and BKM120 (PI3K inhibitor) combination or a BIBW2992 (EGFR inhibitor) and ARQ197 (MET inhibitor) combination and assayed for cell proliferation, apoptosis, and cell cycle distribution. RESULTS: Dual targeting of MEK and PI3K efficiently inhibited the cell proliferation, induced apoptosis and the G0/G1 cell cycle, and decreased the phosphorylation of ERK1/2, AKT, S6, and 4E-BP1. H460 cells with K-RAS and PIK3CA mutation were most sensitive to MEK162 and BKM120 combinations. H1975 cells with EGFR and PIK3CA mutation and MET amplification were sensitive to BIBW2992 and ARQ197 combinations. CONCLUSION: Dual targeting regulated the proliferation of EGFR-TKI-resistant NSCLC cells, especially mutants in K-RAS and PIK3CA that are promising for EGFR-TKI-resistant NSCLC therapeutics.