N-Acetylcysteine Alleviates Cerebral Ischemia-Reperfusion Injury by Inhibiting the JNK/Caspase-3 Signaling Pathway

Abstract

Background: Cerebral ischemia-reperfusion injury (CIRI) is a common neurological disorder involving pathways such as cell apoptosis and inflammation. N-acetylcysteine (NAC), an antioxidant and anti-inflammatory agent, is widely studied for various diseases. However, its specific mechanism in CIRI remains unclear. Therefore, this study aims to explore the mechanism of action of NAC in CIRI. Methods: In this study, we utilized a Middle Cerebral Artery Occlusion (MCAO) mouse model to investigate the effects of N-acetylcysteine (NAC) on cerebral ischemia-reperfusion injury (CIRI). The experimental mice were divided into two groups: the Model group and the NAC treatment group. The NAC was administered after the induction of MCAO. The therapeutic outcomes were assessed through behavioral tests and neuropathological examinations. Quantitative Reverse Transcription Polymerase Chain Reaction (qRT-PCR) was used to measure the levels of inflammatory factors, specifically tumour necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6). Western blot analysis was employed to assess the expression of apolipoprotein E (APOE) following CIRI. The infarct volume post-CIRI was determined using pathological sections and image analysis. Additionally, the impact of NAC on the c-Jun N-terminal Kinase/Cysteine-aspartic Acid Protease-3 (JNK/Caspase-3) signaling pathway in neuronal cells was examined through immunofluorescence and western blot analysis. Results: NAC treatment improved motor and cognitive functions (p < 0.05), reduced neuronal damage, and increased survival rates (p < 0.05). NAC treatment also led to a decrease in inflammatory factors, including TNF-α, IL-1β, and IL-6 after MCAO (p < 0.01). Furthermore, NAC significantly decreased the expression of APOE (p < 0.01), which contributed to neuroprotection. The administration of NAC also reduced the infarct volume induced by MCAO (p < 0.01) and inhibited cell apoptosis (p < 0.05). Hematoxylin and eosin (HE) staining demonstrated that NAC treatment resulted in reduced structural damage in the hippocampal CA1 region. Immunofluorescence and western blot analyses showed that NAC suppressed the expression of JNK, p-c-Jun, Caspase-3, and Caspase-9 in the oxygen-glucose deprivation (OGD) neuronal cell model (p < 0.01). Conclusions: The findings of this study suggest that NAC alleviates CIRI by inhibiting the JNK and Caspase-3 signaling pathways. This reveals the potential mechanism of NAC in the treatment of CIRI and provides a theoretical basis for its clinical application.