TARGETING AGE-DYSREGULATED MICRORNAS TO RESCUE OLIGODENDROCYTE PROGENITOR CELLS DURING AGING

Aging of the central nervous system is associated with progressive myelin loss and inefficient remyelination, largely due to age-dependent functional impairments of oligodendrocyte progenitor cells (OPCs). Although the decline in OPC proliferative and differentiative potential with age is well documented, the underlying molecular mechanisms remain incompletely understood. MicroRNAs (miRNAs) are key post-transcriptional regulators of oligodendrocyte differentiation, yet how miRNA-mediated control changes in OPCs during normal aging is still poorly defined.
Here, we performed an integrated transcriptomic and miRnomic analysis of OPCs isolated from mice at 2, 6 and 12 months of age, corresponding to young adult, adult and early aging stages. OPCs were purified by immunomagnetic separation and analyzed by RNA sequencing. Integrative analysis revealed age-dependent alterations in miRNA–mRNA regulatory networks, identifying a subset of miRNAs whose expression increases with age and whose predicted targets are involved in pathways relevant to OPC differentiation and maturation.
Based on these findings, selected age-associated miRNAs were functionally targeted using a multiplexed Tough Decoy (TuD) approach. We designed and optimized novel TuD constructs with improved miRNA binding site accessibility and multiplexing capacity within lentiviral vectors, enabling the simultaneous inhibition of multiple dysregulated miRNAs. Preliminary in vitro results indicate that optimized TuDs modulate target miRNA activity and influence OPC differentiation.
Overall, this work proposes combined, structurally optimized miRNA modulation as a potential strategy to counteract age-associated OPC dysfunction and promote remyelination in aging.
Funding: PRIN 2022 - - Missione 4 - Componente 2 - Investimento 1.1, CUP: B53D23018510006; FOE D.M 571/2022; PNRR MNESYS (PE0000006)