Hydrogen mitigates brain injury by prompting NEDD4-CX43- mediated mitophagy in traumatic brain injury

Background

Hydrogen (H₂) has emerged as a potential therapeutic intervention for traumatic brain injury (TBI). However, the precise mechanism underlying H₂'s neuroprotective effects in TBI remain incompletely understood.

Methods

TBI mouse model was induced using the controlled cortical impact (CCI) method, and a cell model was established by exposing astrocytes to lipopolysaccharide (LPS). Cell viability was detected by CCK-8 kits. Cell apoptosis was measured by flow cytometry. ELISA was used to detect cytokine quantification. Protein and gene expression was detected by western blot and RT-PCR analysis. Co-immunoprecipitation (CO-IP) were employed for protein-protein interactions. Morris water maze test and rotarod test were applied for TBI mice.

Results

H₂ treatment effectively inhibited the LPS-induced cell injury and cell apoptosis in astrocytes. NEDD4 expression was increased following H₂ treatment coupled with enhanced mitophagy in LPS-treated astrocytes. Overexpression of NEDD4 and down-regulation of connexin 43 (CX43) mirrored the protective effects of H₂ treatment in LPS-exposed astrocytes. NEDD4 interacts CX43 to regulates the ubiquitinated degradation of CX43. While overexpression of CX43 reversed the protective effects of H₂ treatment in LPS-exposed astrocytes. In addition, H₂ treatment significantly alleviated brain injury in TBI mouse model.

Conclusion

H₂ promoted NEDD4-CX43 mediated mitophagy to protect brain injury induced by TBI, highlighting a novel pathway underlying the therapeutic effects of H₂ in TBI.