DJ-1 administration exerts cardioprotection in a mouse model of acute myocardial infarction

Abstract

Cardiovascular diseases, and particularly acute myocardial infarction (MI), are the most common causes of death worldwide. Infarct size is the major predictor of clinical outcomes in MI. The Parkinson's disease associated protein, DJ-1 (also known as PARK7), is a multifunctional protein with chaperone, redox sensing and mitochondrial homeostasis activities. Previously, we provided the evidence for a central role of endogenous DJ-1 in the cardioprotection of post-conditioning. In the present study, we tested the hypothesis that systemic administration of recombinant DJ-1 exerts cardioprotective effects in a mouse model of MI and also explored the associated transcriptional response. We report a significant treatment-induced reduction in infarct size, leukocyte infiltration, apoptosis and oxidative stress. Effects potentially mediated by G-protein-coupled receptor signaling and modulation of the immune response. Collectively, our results indicate a protective role for the exogenously administrated DJ-1 upon MI, and provide the first line of evidence for an extracellular activity of DJ-1 regulating cardiac injury in vivo.

Keywords: DJ-1; PARK7; cardioprotection; ischemia; ischemia/reperfusion injury; myocardial infarction; reperfusion.

FIGURE 1

Effects of systemic DJ-1 administration on infarct size in a mouse model of MI. (A). Representative images of infarcted heart sections. Infarct area is outlined in black. (B). Infarct size quantification after ischemia and ischemia/reperfusion, in the presence and the absence of a systemic administration of DJ-1. Infarct measures are expressed as percentage of left ventricle area. (C). Representative immunohistochemical acquisitions of DJ-1 in the myocardium after ischemia and ischemia/reperfusion, in the presence and the absence of a systemic administration of DJ-1. A sham-operated group was included as baseline. (D). DJ-1 myocardium content quantification across groups. Scale bar: 100 µm; *p < 0.05, Kruskal-Wallis; †p < 0.05 vs. ischemia without DJ-1, ‡p < 0.05 vs. ischemia + DJ-1, #p < 0.05 vs. I/R without DJ-1, Dunn’s test. LV, Left Ventricle; Isch., Ischemia; I/R, Ischemia/Reperfusion.

FIGURE 2

Differential gene expression profile after ischemia/reperfusion, in the presence and the absence of a systemic administration of DJ-1. (A). Heat-map representation of differentially expressed genes. (B). Top ten up- and down-regulated genes after ischemia/reperfusion in the presence of DJ-1 systemic administration. (C). Gprc5a transcript analysis by qPCR. (D). Gene-set enrichment analysis result. Gene-set collections from Wikipathways, Molecular Signature, and Panther databases were considered. *p < 0.05, Mann-Whitney. I/R, Ischemia/Reperfusion; logFC, log-Fold Change.

FIGURE 3

Effects of DJ-1 systemic administration on myocardial leukocyte infiltration after ischemia and ischemia/reperfusion. (A). Representative immunohistochemical acquisitions of myocardial neutrophils (upper panel) and macrophages (lower panel) after ischemia and ischemia/reperfusion in the presence and the absence of a systemic administration of DJ-1. A sham-operated group was included as baseline. (B) and (C) quantification of infiltrated leukocytes. Scale bar: 100 µm; *p < 0.05, Kruskal-Wallis; §p < 0.05 vs. sham, †p < 0.05 vs. ischemia without DJ-1, ‡p < 0.05 vs. ischemia + DJ-1, #p < 0.05 vs. I/R without DJ-1, Dunn’s test. Isch., Ischemia; I/R, Ischemia/Reperfusion.

FIGURE 4

Effects of DJ-1 systemic administration on myocardial apoptosis after ischemia/reperfusion. (A) Casp3 transcript analysis by qPCR. (B) Representative acquisitions of myocardial cleaved Casp-3 immunohistochemistry (upper panel) and TUNEL assay (lower panel) after ischemia/reperfusion. (C) myocardial cleaved Casp-3 immunohistochemistry and TUNEL positive cells quantification. Scale bar: 100 µm; *p < 0.05, Mann-Whitney. I/R, Ischemia/Reperfusion.

FIGURE 5

Systemic DJ-1 administration effects on oxidative stress after ischemia and ischemia/reperfusion. (A) Inos transcript analysis by qPCR. (B) Representative immunohistochemical acquisitions of myocardial iNOS (upper panel) and 8-OHdG (lower panel) after ischemia and ischemia/reperfusion in the presence and the absence of a systemic administration of DJ-1. A sham-operated group was included as baseline. (C) Myocardial iNOS content quantification. (D) Myocardial 8-OHdG content quantification. (E–G) Correlation analyses between iNOS and DJ-1 (E), 8-OHdG and DJ-1 (F), and iNOS and 8-OHdG (G) staining signals. Scale bar: 100 µm; *p < 0.05, Kruskal-Wallis; §p < 0.05 vs. sham, †p < 0.05 vs. ischemia without DJ-1, ‡p < 0.05 vs. ischemia + DJ-1, #p < 0.05 vs. I/R without DJ-1, Dunn’s test; rho, Spearman rank correlation coefficient. Isch., Ischemia; I/R, Ischemia/Reperfusion.