科研之友
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摘要
Aldose reductase (AR), a glucose-metabolizing enzyme, reduces lipid aldehydes and their glutathione conjugates with more than 1000-fold efficiency (K-m aldehydes 5-30 mu M) relative to glucose. Acrolein, a major endogenous lipid peroxidation product as well as a component of environmental pollutants and cigarette smoke, is known to be involved in various pathologies including atherosclerosis, airway inflammation, COPD, and age-related disorders, but the mechanism of acrolein-induced cytotoxicity is not clearly understood. We have investigated the role of AR in acrolein-induced cytotoxicity in primary human small airway epithelial cells (SAECs). Exposure of SAECs to varying concentrations of acrolein caused cell death in a concentration- and time-dependent manner. AR inhibition by fidarestat prevented the low-dose (5-10 mu M) but not the high-dose ( %26gt; 10 mu M) acrolein-induced SAEC death. AR inhibition protected SAECs from low-dose (5 mu M) acrolein-induced cellular reactive oxygen species (ROS). Inhibition of acrolein-induced apoptosis by fidarestat was confirmed by decreased condensation of nuclear chromatin, DNA fragmentation, comet tail moment, and annexin V fluorescence. Further, fidarestat inhibited acrolein-induced translocation of the proapoptotic proteins Bax and Bad from the cytosol to the mitochondria and that of Bc12 and Bc1(xL) from the mitochondria to the cytosol. Acrolein-induced cytochrome c release from mitochondria was also prevented by AR inhibition. The mitogen-activated protein kinases (MAPKs), such as extracellular signal-regulated kinases 1 and 2, stress-activated protein kinase/c-Jun NH2-terminal kinase, and p38MAPK, and c-Jun were transiently activated in airway epithelial cells by acrolein in a concentration- and time-dependent fashion, which was significantly prevented by AR inhibition. These results suggest that AR inhibitors could prevent acrolein-induced cytotoxicity in the lung epithelial cells.
- 出版日期2013-12
