Protein posttranslational modifications play important roles in
cardiovascular diseases. The authors' previous report showed that the abundance of succinylated and glutarylated
proteins was significantly lower in the serum of patients with acute
myocardial infarction (AMI) than in that of healthy volunteers, suggesting a potential relationship between
protein acylation and AMI.
Sirtuin 5 (SIRT5) facilitates the removal of malonyl, succinyl, and glutaryl modification; however, its effects on AMI remain unknown. In this study, the levels of SIRT5 in AMI mouse model was compared. Results showed elevated hepatic SIRT5 after
myocardial infarction. Hepatocyte-specific SIRT5 overexpressing mice (liver SIRT5 OE) were generated to address the possible involvement of hepatic SIRT5 in AMI. The areas of
myocardial infarction, myocardial
fibrosis, and cardiac function in a model of experimental
myocardial infarction were compared between liver SIRT5 OE mice and wild-type (WT) mice. The liver SIRT5 OE mice showed a significantly smaller area of
myocardial infarction and myocardial
fibrosis than the WT mice. The
fibroblast growth factor 21 (
FGF21) in the blood and myocardium of liver SIRT5 OE mice after AMI was markedly elevated compared with that in WT mice. The results of mass spectrometry showed increased levels of
proteins regulating tricarboxylic acid cycle, oxidative phosphorylation, and
fatty acid β-oxidation pathways in the liver mitochondria of liver SIRT5 OE mice. These findings showed that SIRT5 may exhibit a cardioprotective effect in response to acute
ischemia through a liver-cardiac crosstalk mechanism, probably by increasing the secretion of
FGF21 and the improvement of energy metabolism.