Peroxiredoxin-5 Knockdown Accelerates Pressure Overload-Induced Cardiac Hypertrophy in Mice

Abstract

A recent study showed that peroxiredoxins (Prxs) play an important role in the development of pathological cardiac hypertrophy. However, the involvement of Prx5 in cardiac hypertrophy remains unclear. Therefore, this study is aimed at investigating the role and mechanisms of Prx5 in pathological cardiac hypertrophy and dysfunction. Transverse aortic constriction (TAC) surgery was performed to establish a pressure overload-induced cardiac hypertrophy model. In this study, we found that Prx5 expression was upregulated in hypertrophic hearts and cardiomyocytes. In addition, Prx5 knockdown accelerated pressure overload-induced cardiac hypertrophy and dysfunction in mice by activating oxidative stress and cardiomyocyte apoptosis. Importantly, heart deterioration caused by Prx5 knockdown was related to mitogen-activated protein kinase (MAPK) pathway activation. These findings suggest that Prx5 could be a novel target for treating cardiac hypertrophy and heart failure.

Figure 1

Prx5 expression is increased in hypertrophic hearts and isolated NRCMs. (a) The expression of Prx5 in heart tissues was measured by Western blotting and RT-PCR (n = 4, ^∗P < 0.05 vs. the sham group). (c) The expression of Prx5 in heart tissues was measured by Western blotting and RT-PCR (n = 4, ^∗P < 0.05 vs. the PBS group).

Figure 2

Prx5 knockdown accelerates pressure overload-induced cardiac hypertrophy. (a) The levels of Prx5 after injection with AAV9-shPrx5 (n = 4). (b) Results for the HW/BW ratio, HW/TL ratio, LW/BW ratio, LW/TL ratio, and CSA of each group (n = 6). (c) HE and WGA staining were performed in each group (n = 6; scale bar, 50 μm). (d) The expression of ANP, BNP, β-MHC, and Myh7 was measured by RT-PCR in each group (n = 5). ^∗P < 0.05 vs. the sham group; ^#P < 0.05 vs. the TAC group.

Figure 3

Prx5 knockdown accelerates pressure overload-induced cardiac fibrosis. (a) PSR staining was performed in each group (n = 6; scale bar, 50 μm). (b) The expression of collagen I, collagen III, TGF-β, and CTGF was measured by RT-PCR in each group (n = 6). ^∗P < 0.05 vs. the sham group; ^#P < 0.05 vs. the TAC group.

Figure 4

Prx5 knockdown accelerates pressure overload-induced oxidative stress and apoptosis. (a) DHE staining was performed in each group (n = 5; scale bar, 100 μm). (b) Quantitative results of SOD activity and GSH, MDA, and H₂O₂ levels in the hearts of each group (n = 6). ^∗P < 0.05 vs. the sham group; ^#P < 0.05 vs. the TAC group.

Figure 5

Prx5 knockdown accelerates pressure overload-induced apoptosis in mice. (a) TUNEL staining was performed in each group (n = 4; scale bar, 50 μm). (b) The expression of Bax and Bcl-2 was measured by Western blot in each group (n = 4). ^∗P < 0.05 vs. the sham group; ^#P < 0.05 vs. the TAC group.

Figure 6

Prx5 knockdown accelerates AngII-induced cardiomyocyte hypertrophy in vitro. (a) The levels of Prx5 were measured by Western blot (n = 4). (b) Immunofluorescence staining for α-actinin was performed in each group (n = 4; scale bar, 25 μm). (c) The expression of ANP, BNP, β-MHC, and Myh7 was measured by RT-PCR in each group (n = 6). ^∗P < 0.05 vs. the PBS group; ^#P < 0.05 vs. the AngII group.

Figure 7

Prx5 knockdown accelerates AngII-induced oxidative stress and apoptosis in vitro. (a) Quantitative results of SOD activity and GSH, MDA, and H₂O₂ levels in the hearts of each group (n = 6). (c) TUNEL staining was performed in each group (n = 4; scale bar, 50 μm). ^∗P < 0.05 vs. the PBS group; ^#P < 0.05 vs. the AngII group.

Figure 8

Effect of Prx5 on the MAPK signaling pathway. (a) The expression of p-ERK, t-ERK, p-JNK, t-JNK, p-p38, and p38 in the heart was measured by Western blotting (n = 4). (b) The expression of p-ERK, ERK, p-JNK, JNK, p-p38, and p38 in NVCMs was measured by Western blotting (n = 4). ^∗P < 0.05 vs. the sham or PBS group; ^#P < 0.05 vs. the TAC or AngII group.