Integrating phosphoproteome and proteome to reveal key processes through which apocynin protects from lethal ventricular arrhythmias-sudden cardiac death in early myocardial ischemia

  • Toxicol Appl Pharmacol. 2025 Sep:502:117434. doi: 10.1016/j.taap.2025.117434.
Danya Zhou  1 ,  Huishan Liang  2 ,  Xiaojun Zhang  3 ,  Mengxuan Zhang  2 ,  Wei Zhang  2 ,  Ye Zhang  2 ,  Junyao Lv  2 ,  Xudong Xiao  2 ,  Guanghui Zhu  2 ,  Xiaojun Yu  2 ,  Minchao Lai  4 ,  Dian Wang  5
Affiliations
  • 1. School of Forensic Medicine, Xinxiang Key Laboratory of Forensic Toxicology, Xinxiang Medical University, Xinxiang, Henan 453003, China; Department of Forensic Medicine, Shantou University Medical College (SUMC), Shantou, Guangdong 515041, China.
  • 2. Department of Forensic Medicine, Shantou University Medical College (SUMC), Shantou, Guangdong 515041, China.
  • 3. Institute of Marine Sciences and Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, Guangdong 515041, China.
  • 4. Department of Neurology, the First Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong 515041, China. Electronic address: [email protected].
  • 5. Department of Forensic Medicine, Shantou University Medical College (SUMC), Shantou, Guangdong 515041, China. Electronic address: [email protected].
PMID: 40472975 DOI: 10.1016/j.taap.2025.117434
Abstract

The specific role of NADPH oxidases (NOX)-dependent Reactive Oxygen Species (X-ROS) in the development of lethal ventricular arrhythmias (LVA)-sudden cardiac death (SCD) during the early stage of myocardial ischemia (MI) remains poorly understood. Herein, we investigated the impact of X-ROS on LVA-SCD in early MI. The mouse model of MI-induced LVA-SCD and the apocynin (a NOX inhibitor)-pretreated control groups were established. Survival and the electrophysiological parameters were analyzed, and mitochondrial membrane potential (MMP), superoxide dismutase (SOD) activity, ratio of reduced and oxidized glutathione (GSH/GSSG), and ROS and CA2+ levels were assessed. Additionally, cardiac phosphoproteome and proteome analyses were conducted to explore the phosphorylation-related mechanisms by which apocynin protects against LVA-SCD. Our findings revealed that apocynin reduced the incidence of LVA-SCD in early MI and corrected the ECG alterations associated with LVA. Apocynin also mitigated elevated levels of ROS and CA2+ both in mitochondria and cytosol, and decreased GSH/GSSG ratio, SOD activity, and MMP in SCD. After adjusting for proteome data, 548 proteins showed significant changes in their phosphorylation levels in SCD mice. The up-regulated phosphorylated proteins normalized by apocynin were mainly linked to the tricarboxylic acid cycle (TCA), electron transport chain (ETC) function, and calcium signal pathways. The down-regulated phosphorylated proteins normalized by apocynin were mainly relevant to arrhythmogenic right ventricular cardiomyopathy and AMPK signaling pathway. Collectively, our data suggest that X-ROS promotes LVA-SCD in early MI, with CA2+ imbalance and mitochondrial dysfunction, primarily mediated by phosphorylation changes in mitochondrial proteins, playing a crucial role.

Keywords
Apocynin; Mitochondrial function; Myocardial ischemia; NADPH oxidase -independent ROS (X-ROS); Oxidative stress; Phosphorylation.
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