The genetic pathways of ferroptosis-related processes in multiple sclerosis

Abstract

Multiple sclerosis (MS), a chronic inflammatory and neurodegenerative disease with no current cure, in its aetiology comprehend: susceptibility of central nervous system (CNS) to oxidative damage, mitochondrial dysfunction, impaired iron metabolism, which all lead to ferroptosis. Therapeutic capacities to modulate ferroptosis, recently discovered cell death, have been highlighted, in vitro, and require further both bionformatic and experimental research to complement lack of studies in human neurodegenerative diseases. By investigating entire transcriptome in MS patients, we have identified enrichment of the Ferroptosis pathway in DEGs, before clear experimental evidence of its role in MS were presented. Consequently, the FerroReg project aimed to further investigate transcriptional and post-transcriptional regulation of ferroptosis related processes in MS. There is still a lack of specific molecular/ genetic markers that reflect ferroptosis-related molecular changes. A curated assemblage of the ferroptosis-related genes has been performed to create custom panel of 138 genes for targeted mRNA sequencing. The genes were classified according to their roles in relevant processes: lipid oxidative metabolism, antioxidant defence and iron metabolism, next to their proposed direct/indirect effect on ferroptosis. Additionally, 14 encoded transcription regulators which were associated with ferroptosis were included. Ferroptosis draws attention as a biological pathway that could be modulated, to achieve reduction of both inflammation and neurodegeneration in the central nervous system. Accordingly, gene expression was analysed with regard to disease severity, taking into account the disease modifying therapy. Applied approach overcomes the limitation of previous bioinformatic studies, which lacked the clinical data in existing gene expression data sets. Among identified DEGs, 18 genes were upregulated while 8 genes were downregulated in progressive patients compared to mild phenotype. The enrichment analysis performed on the minimum network confirmed the strong enrichment of the ferroptosis pathway while two DEGs were classified as hub molecules: TP53 and CDKN1A.