Cardiac-targeted PIASy gene silencing mediates deSUMOylation of caveolin-3 and prevents ischemia/reperfusion-induced Nav1.5 downregulation and ventricular arrhythmias

• Published in: Military medical research Vol. 9; no. 1; pp. 1 - 58
• Main Authors: Hu, Chen-Chen, Wei, Xin, Liu, Jin-Min, Han, Lin-Lin, Xia, Cheng-Kun, Wu, Jing, You, Tao, Zhu, A.-Fang, Yao, Shang-Long, Yuan, Shi-Ying, Xu, Hao-Dong, Xia, Zheng-Yuan, Wang, Ting-Ting, Mao, Wei-Ke
• Format: Journal Article
• Language: English
• Published: London BioMed Central 14.10.2022; BMC
• Subjects: Antibodies; Biotechnology; Cardiac arrhythmia; Cardiomyocytes; Caveolin-3; Enzymes; Heart; Hypoxia; Ischemia; Kinases; Laboratory animals; Long QT syndrome; Mutation; Nav1.5; Plasmids; Protein inhibitor of activated STAT Y; Proteins; Sodium; SUMOylation; Ventricular arrhythmia; Grand Island New York; United States > US; China; Germany
• ISSN: 2054-9369; 2095-7467; 2054-9369
• DOI: 10.1186/s40779-022-00415-x

Abstract Background Abnormal myocardial Na v 1.5 expression and function cause lethal ventricular arrhythmias during myocardial ischemia–reperfusion (I/R). Protein inhibitor of activated STAT Y (PIASy)-mediated caveolin-3 (Cav-3) SUMO modification affects Cav-3 binding to the voltage-gated sodium channel 1.5 (Na v 1.5). PIASy activity is increased after myocardial I/R, but it is unclear whether this is attributable to plasma membrane Na v 1.5 downregulation and ventricular arrhythmias. Methods Using recombinant adeno-associated virus subtype 9 (AAV9), rat cardiac PIASy was silenced using intraventricular injection of PIASy short hairpin RNA (shRNA). After two weeks, rat hearts were subjected to I/R and electrocardiography was performed to assess malignant arrhythmias. Tissues from peri-infarct areas of the left ventricle were collected for molecular biological measurements. Results PIASy was upregulated by I/R ( P  < 0.01), with increased SUMO2/3 modification of Cav-3 and reduced membrane Na v 1.5 density ( P  < 0.01). AAV9- PIASy shRNA intraventricular injection into the rat heart downregulated PIASy after I/R, at both mRNA and protein levels ( P  < 0.05 vs. Scramble-shRNA + I/R group), decreased SUMO-modified Cav-3 levels, enhanced Cav-3 binding to Na v 1.5, and prevented I/R-induced decrease of Na v 1.5 and Cav-3 co-localization in the intercalated disc and lateral membrane. PIASy silencing in rat hearts reduced I/R-induced fatal arrhythmias, which was reflected by a modest decrease in the duration of ventricular fibrillation (VF; P  < 0.05 vs. Scramble-shRNA + I/R group) and a significantly reduced arrhythmia score ( P  < 0.01 vs. Scramble-shRNA + I/R group). The anti-arrhythmic effects of PIASy silencing were also evidenced by decreased episodes of ventricular tachycardia (VT), sustained VT and VF, especially at the time 5–10 min after ischemia ( P  < 0.05 vs. Scramble-shRNA + IR group). Using in vitro human embryonic kidney 293 T (HEK293T) cells and isolated adult rat cardiomyocyte models exposed to hypoxia/reoxygenation (H/R), we confirmed that increased PIASy promoted Cav-3 modification by SUMO2/3 and Na v 1.5/Cav-3 dissociation after H/R. Mutation of SUMO consensus lysine sites in Cav-3 (K38R or K144R) altered the membrane expression levels of Na v 1.5 and Cav-3 before and after H/R in HEK293T cells. Conclusions I/R-induced cardiac PIASy activation increased Cav-3 SUMOylation by SUMO2/3 and dysregulated Na v 1.5-related ventricular arrhythmias. Cardiac-targeted PIASy silencing mediated Cav-3 deSUMOylation and partially prevented I/R-induced Na v 1.5 downregulation in the plasma membrane of cardiomyocytes, and subsequent ventricular arrhythmias in rats. PIASy was identified as a potential therapeutic target for life-threatening arrhythmias in patients with ischemic heart diseases.