PDCD5, upregulated by SMAD3, ameliorated progressive cardiac fibrosis and cardiac dysfunction post-myocardial infarction by promoting HDAC3 ubiquitination and inhibition.
Does PDCD5 overexpression reduce cardiac fibrosis and improve cardiac function post-myocardial infarction?
PDCD5 acts as a negative feedback factor on fibrotic signaling pathways and may be a potential therapeutic target to suppress cardiac fibrosis post-myocardial infarction.
BACKGROUND: Progressive cardiac fibrosis leads to ventricular wall stiffness, cardiac dysfunction, and eventually heart failure, but the underlying mechanism remains unexplored. PDCD5 (programmed cell death 5) ubiquitously expresses in tissues, including the heart; however, the role of PDCD5 in cardiac fibrosis is largely unknown. Therefore, this study aims at exploring the possible role and underlying mechanisms of PDCD5 in the pathogenesis of cardiac fibrosis. METHODS AND RESULTS: PDCD5 levels were found to be elevated in the serum obtained from patients with cardiac fibrosis, in fibrotic mice heart tissues after myocardial infarction, and in cardiac fibroblasts stimulated by Ang II (angiotensin II)- or TGF-β1 (transforming growth factor-β1). Overexpression of PDCD5 in cardiac fibroblasts or treatment with PDCD5 protein reduced the expression of profibrogenic proteins in response to TGF-β1 stimulation, while knockdown of PDCD5 increased fibrotic responses. It has been demonstrated that SMAD3, a protein that is also known as mothers against decapentaplegic homolog 3, directly upregulated PDCD5 during cardiac fibrosis. Subsequently, the increased PDCD5 promoted HDAC3 (histone deacetylase 3) ubiquitination, thus, inhibiting HDAC3 to reduce fibrotic responses. Fibroblast-specific knock-in of PDCD5 in mice ameliorated cardiac fibrosis after myocardial infarction and enhanced cardiac function, and these protective effects were eliminated by AAV9-mediated HDAC3 overexpression. CONCLUSIONS: The findings of this study demonstrated that PDCD5 is upregulated by SMAD3 during cardiac fibrosis, which subsequently ameliorated progressive fibrosis and cardiac dysfunction through HDAC3 inhibition. Thus, this study suggests that PDCD5 functions as a negative feedback factor on fibrotic signaling pathways and might serve as a potential therapeutic target to suppress the progression of fibrotic responses.
Weng et al. (Thu,) conducted a other in Cardiac fibrosis post-myocardial infarction. PDCD5 overexpression or knock-in vs. Control, PDCD5 knockdown, or HDAC3 overexpression was evaluated on Cardiac fibrosis and cardiac function. PDCD5, upregulated by SMAD3, ameliorated progressive cardiac fibrosis and cardiac dysfunction post-myocardial infarction by promoting HDAC3 ubiquitination and inhibition.