Matrix metalloproteinase-2 and-9 are induced differently by doxorubicin in H9c2 cells: The role of MAP kinases and NAD(P)H oxidase

Objective: Dysregulation of myocardial metalloproteinases (MMPs) is now regarded as an early contributory mechanism for the initiation and progression of heart failure. Doxorubicin is a strongly cardiotoxic anticancer drug. This study investigates the effects of doxorubicin on myocardial MMP-2 and MMP-9 activation. Methods: After pre-treatment with or without carvedilol or dexrazoxane, we exposed H9c2 cardiomyocytes to doxorubicin to evaluate reactive oxygen species (ROS) fort-nation and MMP-2 and MMP-9 expression and activation. To investigate the signaling pathways leading to doxorubicin-induced NIMP activation, we also examined the phosphorylation of three members of the MAPK family (ERK1/2, p38, and JNK), the effects of selective inhibitors of ERK1/2, p38, and INK on MMP transcription and activity, the transcription of the NAD(P)H oxidase subunit Nox1, and the effects of the NAD(P)H oxidase inhibitor DPI on MMP activation. Results: Doxorubicin induces a significant increase in ROS formation and a rapid increase of MMP expression and activation. Pre-treatment with carvedilol or dexrazoxane prevented these effects. We also found that p38 is the MAPK that is mainly responsible for MMP-9 activation through an NAD(P)H-independent mechanism. ERK and JNK modulate the transcription of the NAD(P)H oxidase subunit Nox1, while the JNK/ERK NAD(P)H oxidase cascade is an important pathway that mediates doxorubicin signaling to MMP-2. Inhibition of NAD(P)H oxidase attenuates the increase in MMP-2, but augments the doxorubicin-induced increase in MMP-9. Conclusions: Enhancement of MMP-2 and MMP-9 in cardiac myocytes in response to doxorubicin is mediated by the cooperation of ERK, JNK, and p38 kinase pathways, most of which are redox dependent. (c) 2005 European Society of Cardiology. Published by Elsevier B.V. All rights reserved.