Effect of valproic acid (VPA) on acetylated histone H3 (Ac-H3) expression in lung tissue. VPA up-regulated Ac-H3 expression in a dose-dependent manner in ischemia–reperfusion (I/R) lung injury. TATA served as loading controls for nuclear proteins. A representative blot is shown. Data are expressed as mean ± SD (n = 3 per group). ***P < 0.001 compared with the control group; +++P < 0.001 compared with the I/R–vehicle group. *P < 0.05; **P < 0.01; ++P < 0.01.