Downregulation of PFN1 exerts neuroprotective effects in epilepsy by stabilizing calcium homeostasis and suppressing oxidative stress via regulating RhoA/ROCK2 signaling pathway

Epilepsy is one of the most common neurological disorders worldwide, with pathogenesis involving abnormal neuronal networks and oxidative damage. Effective interventions remain limited, highlighting the importance of exploring novel targets. This study aimed to investigate how downregulation of profilin-1 (PFN1) exerts neuroprotective effects by stabilizing calcium homeostasis and suppressing oxidative stress in hippocampal neurons via the RhoA/ROCK2 signaling pathway in epilepsy.

Bioinformatics analysis was performed using the Gene Expression Omnibus (GEO) and the Human Protein Atlas (THPA) databases to identify key differentially expressed genes in temporal lobe epilepsy. For in vivo experiments, 82 male C57 BL/6 mice (aged 8 to 10 weeks, weighting 20 to 25 g) were divided into control, epileptic model, vector control, and PFN1-interfered groups. The vector control and PFN1-interfered groups received stereotactic injections of siCon or siPFN1 complexes, respectively, followed by kainic acid (KA)-induced epilepsy modeling 72 h later; the other 2 groups received saline and KA only. RT-qPCR and Western blotting validated PFN1 expression in hippocampal neurons. Electroencephalogram and Racine scores were used to evaluate seizure characteristics and electroencephalographic features. Open field tests assessed spontaneous locomotion and exploratory behavior. RT-qPCR, Western blotting, immunohistochemistry, and histological staining analyzed PFN1's protective effects against hippocampal neuronal injury. For in vitro experiments, HT22 cells were pretreated with PFN1 interference before establishing the epileptic cell models using Mg²⁺-free extracellular fluid under identical conditions, with calcium imaging, reactive oxygen species(ROS) probes, and flow cytometry assessing calcium homeostasis and oxidative stress. Co-immunoprecipitation and Western blotting verified PFN1's interaction with the RhoA/ROCK2 pathway.

Bioinformatic analyses revealed significant upregulation of PFN1 expression in epileptic models. Results from characterization demonstrated elevated PFN1 transcription and protein expression (P<0.01) in epileptic model, with PFN1 co-localized with NeuN in the cytoplasm of hippocampal CA1/CA3 neurons. PFN1 knockdown significantly reduced Racine scores (P<0.001), prolonged seizure latency (P<0.001), improved epileptiform discharges and neuronal morphology, and increased NeuN-positive cells and Nissl bodies (P<0.01). Mechanistically, PFN1 formed a complex with RhoA and ROCK2; Its knockdown suppressed pathway protein expression (P<0.05), downregulated CaMK2 levels (P<0.05), and inhibited calcium influx (P<0.001) and ROS generation (P<0.001).

Downregulation of PFN1 may protect neurons in epilepsy by stabilizing calcium homeostasis and suppressing oxidative stress through the RhoA/ROCK2 signaling pathway.