Integrating weighted gene co-expression network analysis and machine learning reveal that NDUFA4L2 alleviates KA-induced HT22 cell neurotoxicity, apoptosis, oxidative stress, and mitochondrial dysfunction.

Temporal lobe epilepsy (TLE) is one of the most common types of epilepsy, with frequent seizures often leading to cognitive, emotional, and psychiatric issues. A prominent pathological change associated with TLE is hippocampal sclerosis (HS), characterized by neuronal loss, gliosis, and increased neuron fibre density. However, the pathogenesis of Temporal lobe epilepsy with hippocampal sclerosis (TLE-HS) remains unclear. This study aimed to investigate the abnormal expression and regulatory mechanism of hub genes in TLE-HS. The source data were obtained from the epilepsy dataset (GSE256068) of the Gene Expression Omnibus GEO database. Then, differential expression gene (DEG) analysis and weighted gene coexpression network analysis (WGCNA) were employed to screen for module-related DEGs in TLE-HS, followed by gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Subsequently, these intersected targets were subjected to cross-validation using three machine learning algorithms- LASSO regression, SVM-RFE, and RF, ultimately identifying three hub genes. Finally, CIBERSORT and ssGSEA algorithms were used to analyze the infiltration status of different immune cell populations in TLE-HS patients, followed by assessing the association between hub genes and immune cell populations. The expression of hub genes was determined using RT-qPCR and western blot. Functional experiments were performed using CCK-8, flow cytometry, and special kits. Results indicated that three hub genes, NADH dehydrogenase (ubiquinone) 1 alpha subcomplex subunit 4-like 2 (NDUFA4L2), Protein-tyrosine Phosphatase 4A3 (PTP4A3), and Zinc-alpha-2-glycoprotein (AZGP1), were identified in TLE-HS, which are associated with the infiltration of specific immune cells. Besides, NDUFA4L2 expression was reduced in kainic acid (KA)-induced HT22 cells compared to the other two hub genes. Thus, NDUFA4L2 was selected for this research. Moreover, NDUFA4L2 overexpression alleviated KA‑induced HT22 cell neurotoxicity, apoptosis, oxidative stress, and mitochondrial dysfunction. In conclusion, NDUFA4L2 upregulation could alleviate KA-induced neurotoxicity oxidative stress, which provided a theoretical foundation and a potential therapeutic target for epilepsy.