Figure 3
From: Pleiotropic Effects of Myocardial MMP-9 Inhibition to Prevent Ventricular Arrhythmia
MMP-9 deficiency prevents RyR2 phosphorylation in cardiomyocytes.
(A) Expression of RyR2 receptor phosphorylated at serine 2808 (pS2808) and 2814 (pS2814) in mouse ventricular tissue. The increased level of pS2808 in the WT mice after Ang II treatment that correlated with a ventricular arrhythmia attack was prevented in the MMP-9−/− mice (n = 6, *P < 0.05 vs. WT + vehicle; #P < 0.05 vs. WT + Ang II). (B) Corresponding changes in PKA and CaMKII in mouse ventricular tissue (n = 6, *P < 0.05 vs. WT + vehicle; #P < 0.05 vs. WT + Ang II). (C) Representative Western blot showing phosphorylated RyR2 and PKA in mouse ventricular tissue. (D to G) MMP-9 expression was knocked down by siRNA in HL-1 cardiomyocytes (D), which prevented RyR2 hyperphosphorylation (E) and regulated PKA and CaMKII expression (F). (G) Representative Western blot in HL-1 cardiomyocytes. (D) to (G), (n = 4–6, *P < 0.05 vs. WT + vehicle, #P < 0.05 vs. WT + Ang II). Data are presented as the mean ± SEM.
