Hypoxia-ischemia-induced Ntoco promotes ferroptosis via the Hnrnpab-mediated NF κB/Lcn2 axis following traumatic brain injury in mice

Evidence supports the contribution of long non-coding RNAs (lncRNAs) and ferroptosis to traumatic brain injury (TBI) pathogenesis. However, lncRNA regulation in TBI-induced ferroptosis remains poorly understood. Herein, we identified an lncRNA, named noncoding transcript of chemokine (C-C motif) ligand 4 (Ccl4) overlapping (Ntoco), which was upregulated in TBI mice. The upregulation was initiated by hypoxia ischemia induced lower enrichment of H3K27me3 on the Ntoco promoter. Ntoco knockdown inhibited neuron ferroptosis, ameliorated spatial memory and lesion volume following TBI. Ntoco overexpression promoted neuron ferroptosis and recruited microglia to provoke an inflammatory response via Ccl4. Mechanistically, Ntoco facilitated K48-linked ubiquitination and protein degradation by binding to Hnrnpab, which suppressed NF-κB/Lcn2 signal axis activation, including decreased phosphorylation of IkBα, increased phosphorylation of IKKα/β, nuclear translocation of the NF-κB p65 subunit, and elevated Lcn2 expression. These data indicated that targeting Ntoco to mitigate ferroptosis might be a potential therapeutic strategy for TBI.