Stimulation of Na⁺/K⁺-ATPase with an Antibody against Its 4^th Extracellular Region Attenuates Angiotensin II-Induced H9c2 Cardiomyocyte Hypertrophy via an AMPK/SIRT3/PPARγ Signaling Pathway

Figure 4

Effect of DR-Ab on myocyte hypertrophy and intracellular ROS generation in Ang II-treated H9c2 in the presence and absence of compound C (40 μM, a selective AMPK inhibitor), 3-TYP (50 μM, a selective Sirt3 inhibitor), or GW9662 (10 μM, a PPARγ antagonist). Cells were treated with these inhibitors for 30 min before DR-Ab (2 μM, 30 min) and Ang II (100 nM, 48 h). (a, b) Representative immunofluorescence staining (a) and group data (b) showing that blockade of AMPK, Sirt3, or PPARγ abolished the effect of DR-Ab on cell size. Red: α-actinin. Blue: DAPI. Scale bar, 25 μm. . (c–f) Representative image (c, e) and group data (d, f) showing that blockade of AMPK, Sirt3, or PPARγ promoted the intracellular ROS which were decreased by DR-Ab in Ang II-induced cells. (c) Red: DHE relative fluorescence density. Scale bar, 100 μm. (e) Green: DCFH-DA staining. Scale bar, 50 μm. . versus control, versus Ang II alone group, ^‡ versus Ang II+DR-Ab group.

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