Inhibiting the ROCK Pathway Ameliorates Acute Lung Injury in Mice following Myocardial Ischemia/reperfusion.

To clarify the role of Y-27632, a selective inhibitor of Rho-associated coiled-coil forming protein kinase (ROCK), in acute lung injury (ALI) induced by myocardial ischemia/reperfusion (I/R). Mice were randomized into Sham, I/R, and Y-27632 (10, 20 or 30 mg/kg) + I/R groups, and hemodynamics, infarcted area, the protein concentration, neutrophils in bronchoalveolar lavage fluid (BALF), malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) levels were assessed. Pathological changes were evaluated by hematoxylin-eosin (HE) staining; protein and gene expression were measured by Western blotting, enzyme-linked immunosorbent assay (ELISA), immunohistochemistry and quantitative real-time reverse-transcription polymerase chain reaction (qRT-PCR); and apoptosis was assessed by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling (TUNEL) staining. ROCK1 and ROCK2 expression was up-regulated in lung tissues of I/R mice compared to sham mice. Y-27632 decreased the protein concentration and the neutrophils in BALF in I/R mice, improved hemodynamics and reduced infarct size (IS)/area at risk (AAR) ratio. In addition, pathological changes in lung tissues of Y-27632-treated mice were mitigated, and these alterations were accompanied by decreases in MDA levels in lung tissues and increases in SOD and GSH-Px levels. Moreover, in I/R group, the number of apoptotic cells in lung tissue was higher than that in sham group, and p53, Caspase-3 and Bax expression was up-regulated; however, following treatment with Y-27632 (10, 20 and 30 mg/kg), these changes were reversed. Inhibition of ROCK pathway by Y-27632 ameliorated ALI in myocardial I/R mice by mitigating oxidative stress, inflammation and cell apoptosis.

Tanshinone IIA induces cytochrome c-mediated caspase cascade apoptosis in A549 human lung cancer cells via the JNK pathway.

Tanshinone IIA (TSIIA), a natural diterpene quinone in the traditional Chinese medicinal herb Dan-Shen (Salvia miltiorrhiza), has extensively exerted antitumor activity in cellular and animal models. However, the molecular mechanisms underlying the antitumor effects of TSIIA remain largely unknown. The in vitro effects of TSIIA on apoptosis were investigated in A549 non-small cell lung cancer (NSCLC) cells. The data showed that TSIIA significantly suppressed the proliferation of A549 cells in a dose-dependent manner, with IC50 values of 16.0±3.7 and 14.5±3.3 µM at 48 h as determined by Cell Counting Kit-8 (CCK-8) assay and clone formation assay, respectively. The change of mitochondrial morphology and the loss of mitochondrial membrane potential (MMP) were observed during the induction. Furthermore, TSIIA induced A549 cell apoptosis as confirmed by typical morphological changes, with cytochrome c release from the mitochondria and Bax translocation to the mitochondria. Caspase activity data indicated that TSIIA activated caspase-9 and caspase-3 of mitochondria-mediated apoptosis, but not caspase-8 of receptor-mediated apoptosis, which could be largely rescued by SP600125 (JNK inhibitor). Taken together, these findings provide the first evidence that TSIIA inhibits growth of NSCLC A549 cells, induces activation of JNK signaling and triggers caspase cascade apoptosis mediated by the release of cytochrome c, which provides a better understanding of the molecular mechanisms of TSIIA on lung cancer.