ZNF503-AS-Pep1 mitigates neuroinflammation and oxidative stress via HMGA2 in a microglia-mediated neuroinflammatory cell model

Abstract

Neuroinflammation and oxidative stress are critical pathological drivers in various neurological and neuropsychiatric disorders, with IL6 and reactive oxygen species (ROS) as key factors. This study investigated the lncRNA-derived peptide ZNF503-AS-Pep1’s role in modulating these pathways in cell model in vitro and its molecular mechanism. In this study, HMC3 cells were used to construct an LPS-induced inflammatory cell model to simulate a neuroinflammatory condition. Oxidative stress was evaluated by measuring ROS, MDA, and SOD levels. Dual-luciferase reporter assays assessed the impact on the transcriptional activity of IL6 promoter. Enzyme-linked immunosorbent assay (ELISA) and RT-qPCR were used to measure IL6 level. DNA pull-down combined with MS was utilized to identify proteins interacting with the IL6 promoter region. Co-immunoprecipitation (Co-IP) and Venn diagram analyses were employed to further determine key intermediate regulatory proteins between ZNF503-AS-Pep1 and IL6. Chromatin immunoprecipitation (ChIP-PCR and ChIP-qPCR) and computational structural modeling were performed to elucidate protein-DNA and peptide-protein interactions, while antisense oligonucleotides (ASOs) were utilized for loss-of-function validation. The results showed that ZNF503-AS-Pep1 markedly reduced IL6 transcription and secretion, effectively mitigating the pro-inflammatory state and oxidative damage in LPS-stimulated HMC3 cells, whereas knockdown of endogenous ZNF503-AS-Pep1 exacerbated these pathological phenotypes. HMGA2 was identified as a key intermediary protein connecting ZNF503-AS-Pep1 and IL6, with ZNF503-AS-Pep1 inhibiting HMGA2’s enhancement of IL6 transcription by physically hindering HMGA2 occupancy at the IL6 promoter. Additionally, ZNF503-AS-Pep1 alleviated HMGA2-induced oxidative damage, as evidenced by reduced ROS and MDA levels and increased SOD activity. In conclusion, ZNF503-AS-Pep1 exerted a protective role in reducing IL6 transcription and oxidative damage by modulating HMGA2 in an inflammatory cell model. These findings suggested that ZNF503-AS-Pep1 could serve as a promising therapeutic candidate for mitigating neuroinflammation and oxidative stress in neuroinflammatory disorders, including schizophrenia.