Cardiac Nuclear High-Mobility Group Box 1 Ameliorates Pathological Cardiac Hypertrophy by Inhibiting DNA Damage Response.

High-mobility group box 1 (HMGB1) is a deoxyribonucleic acid (DNA)-binding protein associated with DNA repair. Decreased nuclear HMGB1 expression and increased DNA damage response (DDR) were observed in human failing hearts. DNA damage and DDR as well as cardiac remodeling were suppressed in cardiac-specific HMGB1 overexpression transgenic mice after angiotensin II stimulation as compared with wild-type mice. In vitro, inhibition of HMGB1 increased phosphorylation of extracellular signal-related kinase 1/2 and nuclear factor kappa B, which was rescued by DDR inhibitor treatment. DDR inhibitor treatment provided a cardioprotective effect on angiotensin II-induced cardiac remodeling in mice.