Ntoco Promotes Ferroptosis via Hnrnpab-Mediated NF-κB/Lcn2 Axis Following Traumatic Brain Injury in Mice

Emerging evidence highlights the involvement of long non-coding RNAs (lncRNAs) and ferroptosis in the pathogenesis of traumatic brain injury (TBI). However, the regulatory role of lncRNAs in TBI-induced ferroptosis remains poorly understood. This study aims to investigate the role of a specific lncRNA, noncoding transcript of chemokine (C-C motif) ligand 4 (Ccl4) overlapping (Ntoco), in the regulation of ferroptosis following TBI and explore its potential as a therapeutic target.

The expression levels of Ntoco following controlled cortical injury (CCI) in mice were measured using real-time PCR. Behavioral tests post-injury were assessed using the rotarod test and Morris water maze, and lesion volume was evaluated using micro-MRI. Ntoco binding proteins were identified using RNA pull-down and RNA immunoprecipitation. RNA sequencing was employed to identify Ntoco-related pathways. Western blotting and co-immunoprecipitation were used to measure protein levels and ubiquitination processes.

Ntoco upregulation was observed in CCI mice. Ntoco knockdown inhibited neuron ferroptosis, reduced lesion volume, and improved spatial memory following TBI. Ntoco overexpression promoted ferroptosis in neurons. Mechanistically, Ntoco facilitated K48-linked ubiquitination and degradation of proteins by binding to Hnrnpab, suppressing the NF-κB/Lcn2 signaling pathway. This included reduced phosphorylation of IkBα, increased phosphorylation of IKKα/β, nuclear translocation of the NF-κB p65 subunit, and elevated Lcn2 expression.

Our findings suggest that Ntoco plays a crucial role in TBI-induced ferroptosis by modulating the NF-κB/Lcn2 signaling pathway. Targeting Ntoco may provide a promising therapeutic strategy to mitigate ferroptosis and improve outcomes following TBI.