NOX2, p22phox and p47phox are Targeted to the Nuclear Pore Complex in Ischemic Cardiomyocytes Colocalizing with Local Reactive Oxygen Species

Cellular Physiology and Biochemistry

关键词: Cardiomyocytes;    NADPH oxidase;    Reactive oxygen species;    Nuclear pore complex;    Apoptosis;   

DOI  :  10.1159/000329968

学科分类：分子生物学，细胞生物学和基因

来源: S Karger AG

【 摘 要 】

Background NADPH oxidases play an essential role in reactive oxygen species (ROS)-based signaling in the heart. Previously, we have demonstrated that (peri)nuclear expression of the catalytic NADPH oxidase subunit NOX2 in stressed cardiomyocytes, e.g. under ischemia or high concentrations of homocysteine, is an important step in the induction of apoptosis in these cells. Here this ischemia-induced nuclear targeting and activation of NOX2 was specified in cardiomyocytes. Methods The effect of ischemia, mimicked by metabolic inhibition, on nuclear localization of NOX2 and the NADPH oxidase subunits p22^phox and p47^phox, was analyzed in rat neonatal cardiomyoblasts (H9c2 cells) using Western blot, immuno-electron microscopy and digital-imaging microscopy. Results NOX2 expression significantly increased in nuclear fractions of ischemic H9c2 cells. In addition, in these cells NOX2 was found to colocalize in the nuclear envelope with nuclear pore complexes, p22^phox, p47^phox and nitrotyrosine residues, a marker for the generation of ROS. Inhibition of NADPH oxidase activity, with apocynin and DPI, significantly reduced (peri)nuclear expression of nitrotyrosine. Conclusion We for the first time show that NOX2, p22^phox and p47^phox are targeted to and produce ROS at the nuclear pore complex in ischemic cardiomyocytes.

【 授权许可】

CC BY-NC-ND