Deubiquitinase Inhibitor Auranofin Attenuated Cardiac Hypertrophy by Blocking NF-κB Activation

Cardiac hypertrophy is a major outcome and compensatory response of the cardiovascular system to hemodynamic and additional stress responses that ultimately lead to heart failure. Auranofin (Aur) has been used for treating rheumatic arthritis for several decades. Aur is a 19S proteasome-associated deubiquitinase inhibitor, and inhibition of the proteasome is speculated to reverse cardiac hypertrophy. However, the role of the deubiquitinases, especially 19S proteasome-associated deubiquitinases, in the regulation of cardiac remodeling remains poorly understood. The present study investigated the role of Aur in cardiac hypertrophy both in vitro and in vivo.

Male Sprague-Dawley rats underwent abdominal aortic constriction to induce left ventricular hypertrophy. The neonatal rat primary myocardial cell hypertrophy model was induced by Ang II. Echocardiography, hematoxylin-eosin staining, Masson's trichrome staining, immunochemistry, western blot analysis, a cell viability assay, and enzyme-linked immunosorbent assay were performed.

Aur significantly reduced the abdominal aortic constriction that led to left ventricular hypertrophy, reduced heart cavity expansion, and functional disorder, and thereby reduced fetal gene expression and attenuated cardiac fibrosis. Furthermore, Aur caused marked accumulation of ubiquitinated proteins and IκBα, as well as inactivation of NF-κB. This phenomenon was confirmed in the neonatal rat primary myocardial cell hypertrophy model.

The present study indicated that Aur blocks the development of left ventricular hypertrophy induced by abdominal aortic constriction. This phenomenon might be attributed to inhibition of the 19S proteasome-associated deubiquitinase that can lead to aggregation of IκBα and inactivation of the NF-κB pathway. Thus, Aur could be a potential anti-cardiac hypertrophy agent.