Peroxiredoxin 3 Inhibits Cardiac Fibrosis in Mice via NOX4-P38 Signalling

OBJECTIVE: Peroxiredoxin-3 (Prx-3) is widely acknowledged as an antioxidant that protects against mitochondrial reactive oxygen species. Nonetheless, its role in cardiac fibrosis has not been elucidated. We aim to explore the role and mechanism of Prx-3 in cardiac fibrosis. MATERIALS AND METHODS: In this experimental study, mice received subcutaneous injections of isoproterenol (ISO) for 14 consecutive days (10 mg/kg/d for three days, followed by 5 mg/kg/d for 11 days) to establish a cardiac fibrosis model. The mice were subsequently injected with adenovirus-Prx-3 (ad-Prx-3) to enable Prx-3 overexpression. Echocardiography was used to evaluate cardiac function. Mice heart fibroblasts were isolated and stimulated with transforming growth factor β1 (TGFβ1) to induce fibrosis in vitro. Cells were also transfected with ad-Prx-3 for overexpression of Prx-3. RESULTS: Echocardiographic diameters and fibrosis markers indicated that Prx-3 could inhibit ISO-induced cardiac dysfunction and fibrosis. Fibroblasts with Prx-3 overexpression exhibited reduced activation, proliferation, and collagen transcription. We found that Prx-3 reduced the expression of NADPH oxidase 4 (NOX4) and reduced P38 levels. After treatment with a P38 inhibitor, the Prx-3 overexpression-induced anti-fibrosis effect was mitigated. CONCLUSION: Prx-3 could protect against ISO-induced cardiac fibrosis by inhibiting the NOX4-P38 pathway.