NPPB and cardiac hypertrophy: In HFD + L-NAME mice, the expression of HDAC6 protein was also increased (Fig. 2c), correlated with the upregulation of Nppb and Col3a1, and severity of diastolic dysfunction [based on the early diastolic velocity ratio (E/e’)] and cardiac hypertrophy (based on LVPWd) (Supplementary Fig. 2i, j).