Post-transcriptional Regulatory Networks in Cuprizone Demyelination and Remyelination: Identification of RBM45 as a Novel Cross-Species Candidate RNA Binding Protein

Abstract Remyelination the regenerative process by which oligodendrocytes restore myelin sheaths following demyelinating injury is regulated at multiple levels, yet the post-transcriptional mechanisms governing this transition remain poorly understood. RNA-binding proteins (RBPs) control mRNA stability, localization, splicing, and translation through interactions with 3' untranslated region (3'UTR) sequence motifs, but a systematic analysis of RBP regulatory networks across the demyelination-remyelination axis has not previously been performed. Here, we analyzed publicly available bulk RNA-seq data from the cuprizone mouse model of demyelination and remyelination (GSE255368; control n = 5, demyelination n = 4, recovery n = 4) using DESeq2 differential expression analysis, identifying 682 differentially expressed genes (DEGs) during peak demyelination and 459 DEGs during the remyelination transition. Three biologically distinct gene sets were defined: neuroinflammatory transcripts upregulated during demyelination (n = 611), transcripts suppressed during recovery (n = 395), and myelin-associated transcripts activated during remyelination (n = 64). 3'UTR sequences were extracted for each gene set and submitted to RBPmap for motif enrichment analysis against a database of 132 human and mouse RBP binding motifs. We identify a core post-transcriptional regulatory network of seven RBPs — RBM45, PUF60, PCBP2, HNRNPDL, RBM6, FUBP3, and HNRNPL consistently enriched across all three gene sets, with mean enrichment scores of 47–80% of sequences per gene set. Network analysis reveals that canonical myelin transcripts Mbp, Plp1, Mal, Opalin , and Cldn11 serve as convergence hubs targeted by all 15 top RBPs simultaneously, suggesting combinatorial post-transcriptional regulation of the remyelination gene program. Cross-species analysis with human MS transcriptomic data (GSE138614) identified 161 conserved demyelination genes between mouse and human (r = 0.286 fold-change correlation), and RBP motif analysis confirmed 7 of the top 20 mouse RBP candidates, including RBM45 as the lead hit are also detected in human MS active lesions, providing the first cross-species evidence for RBM45 involvement in demyelinating disease. These findings establish a translatable post-transcriptional regulatory framework for CNS demyelination and identify RBM45 as a high-priority experimental target across both mouse and human demyelinating disease.