Inhibition of Connexin43 Improves the Recovery of Spinal Cord Injury Against Ferroptosis via the SLC7A11/GPX4 Pathway

• Published in: Neuroscience Vol. 526; pp. 121 - 134
• Main Authors: Huang, Qun, Sha, Weiping, Gu, Qi, Wang, Jin, Zhu, Yi, Xu, Tianli, Xu, Zhenhua, Yan, Fei, Lin, Xiaolong, Tian, Shoujin
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 21.08.2023
• Subjects: connexin43; ferroptosis; neuroprotection; P-mTOR; spinal cord injury; spinal cord injury; OCT; ferroptosis; BBB; connexin43; CX43; MDA; CT; 4-HNE; neuroprotection; P-mTOR; ROS; SCI; Fer-1; GSH
• ISSN: 0306-4522; 1873-7544
• DOI: 10.1016/j.neuroscience.2023.06.017

•Inhibition of CX43 decreased P-mTOR/mTOR and reversed the decreasing of SLC7A11.•Inhibition of CX43 increased the levels of GPX4 and GSH.•Inhibition of CX43 suppressed the levels of 4-HNE and MDA.•Inhibition of CX43 reduced ferroptosis and therefore improved the functional recovery after SCI. Ferroptosis plays a key role in the process of spinal cord injury (SCI). As a signal amplifier, connexin 43 (CX43) participates in cell death signal transduction and aggravates the propagation of injury. However, it remains unclear whether CX43 plays a regulatory role in ferroptosis after SCI. The SCI rat model was established by an Infinite Vertical Impactor to investigate the role of CX43 in SCI-induced ferroptosis. Ferrostatin-1 (Fer-1), an inhibitor of ferroptosis, and a CX43-specific inhibitor (Gap27) were administered by intraperitoneal injection. Behavioral analysis was assessed according to the Basso-Beattie-Bresnahan (BBB) Motor Rating Scale and the inclined plate test. The levels of ferroptosis-related proteins were estimated by qRT-PCR and western blotting, while the histopathology of neuronal injury induced by SCI was evaluated by immunofluorescence, Nissl, FJB and Perl’s Blue staining. Meanwhile, transmission electron microscopy was used to observe the ultrastructural changes characteristic of ferroptosis. Gap27 strongly inhibited ferroptosis and therefore improved the functional recovery of SCI, which was similar to the treatment of Fer-1. Notably, the inhibition of CX43 decreased P-mTOR/mTOR expression and reversed the decrease in SLC7A11 induced by SCI. As a result, the levels of GPX4 and glutathione (GSH) increased, while the levels of the lipid peroxidation products 4-hydroxynonenal (4-HNE) and malondialdehyde (MDA) decreased. Together, inhibition of CX43 could alleviate ferroptosis after SCI. These findings reveal a potential mechanism of the neuroprotective role of CX43 after SCI and provide a new theoretical basis for clinical transformation and application.