Bard1-Mediated Regulation of Hnrnpa2b1 Ubiquitination and Protein Stability Contributes to Neuronal Ferroptosis and Cognitive Dysfunction Following Ischemic Stroke.

AIMS: N6-methyladenosine (m6A) facilitates functional recovery following ischemic stroke (IS). This study investigated the role of Sptbn2 in post-stroke cognitive impairment (PSCI) and the mechanisms regarding m6A. METHODS: HT-22 cell damage and ferroptosis were analyzed following OGD exposure. pMCAO surgery was performed to establish an IS mouse model. We assessed neurological deficits and cognitive impairment in mice using the mNSS, adhesive removal test, rotarod test, novel object recognition test, and Y-maze test. Adeno-associated viral vectors with overexpression of Sptbn2 combined with pMCAO surgery were used to analyze cognitive dysfunction and ferroptosis. RESULTS: Sptbn2 was reduced in neurons of PSCI mice. Sptbn2 overexpression alleviated ferroptosis-induced neuronal damage by promoting the membrane translocation of Slc7a11. Hnrnpa2b1 promoted Sptbn2 stability through an m6A-related mechanism. Knockdown of Sptbn2 reversed the mitigation of ferroptosis by Hnrnpa2b1 and exacerbated the neuronal injury. Under OGD, Bard1 knockdown reduced the Hnrnpa2b1 ubiquitination, slowed Hnrnpa2b1 degradation, and restored Sptbn2 expression. Knockdown of Bard1 alleviated neuronal ferroptosis, thereby reducing the development of cognitive impairment in mice, a phenotype reversed by Hnrnpa2b1 or Sptbn2 knockdown. CONCLUSION: In IS, Bard1-associated regulation of Hnrnpa2b1 ubiquitination is accompanied by reduced Sptbn2 expression and impaired Slc7a11 membrane translocation, and is involved in neuronal ferroptosis-related damage.