Contrasting roles of NADPH oxidase isoforms in cardiac remodeling

Early research demonstrated that NADPH oxidase was important in cardiac remodeling induced by angiotensin II(AngII).In later studies,a total of five NOX enzymes and two related enzymes were discovered and two main isoforms,Nox2 and Nox4,were found expressed in the heart.Nox2 could promote the development of cardiac remodeling induced by AngII,myocardial infarction and chemotherapeutic agent doxorubicin,whereas Nox4 mRNA increased significantly in pressure-overload left ventricular hypertrophy.Therefore,Nox2 and Nox4 play different roles in cardiac remodeling.A better understanding of these enzymes as well as their roles in cardiac remodeling may lead to new therapeutic targets based on modulation of Nox activity.