Increased OPN expression in the heart induces oxidative stress, and increases expression of NOX−4 and BIK Left ventricular lysates, prepared 4 weeks after doxycycline withdrawal, were analyzed by oxyblot assay (a), or by western blots using anti-NOX−4 (b) and anti-BIK (c) antibodies. a The right panel depicts oxyblot image obtained from SHAM and MHC-OPN samples, while the left panel depicts the mean data normalized to SYPRO ruby staining, *p < 0.05 versus SHAM; n = 3–4. The lower panels in b and c exhibit the mean data normalized to GAPDH, *p < 0.05 versus SHAM; n = 3–4