Phosphorylation of cAMP-Activated Exchange Protein-1 Participates in Neuroprotection and Ferroptosis Regulation...

Intracerebral hemorrhage (ICH) is a severe condition characterized by elevated mortality and disability rates. The cAMP-activated exchange protein-1 (EPAC-1) is implicated in various cytoprotective mechanisms; however, its specific role in ICH remains unclear.

A rat model of ICH was established by injecting autologous blood, while the in vitro primary neuronal model was stimulated using oxyhemoglobin (OxyHb). The construction of EPAC-1 overexpression wild-type (WT) and phosphorylated mutant plasmids (S108A or S108E), as well as lentiviruses, was performed for in vitro and in vivo studies.

The cAMP signaling pathway was found to be significantly enriched following ICH by high-throughput sequencing analysis. Our findings showed that while EPAC-1 protein levels remained relatively unchanged after ICH, RabGEF activity was conspicuously upregulated. This was accompanied by a marked decrease in EPAC-1 phosphorylation levels. Mutations that activate EPAC-1 phosphorylation led to significant improvements in neuronal survival and behavioral outcomes after ICH. Bioinformatics analysis revealed that ferroptosis was significantly enriched after ICH and showed a positive correlation with EPAC-1 serine phosphorylation. EPAC-1 phosphorylation activating mutations inhibit neuronal ferroptosis, whereas inactivating mutations exacerbate it.

The phosphorylation of EPAC-1 is essential for maintaining neuronal survival, which may be related to ferroptosis inhibition after ICH.