Transcriptome analysis of freshly isolated young and aged rat oligodendrocyte progenitor cells (OPCs)

The age-related failure to regenerate lost oligodendrocytes from oligodendrocyte progenitor cells (OPCs) is associated with irreversible neurodegeneration in multiple sclerosis. Consequently, regenerative therapies for chronic demyelinating diseases remain a long sought after but elusive goal. Here we show that adult OPCs lose their inherent differentiation potential with increasing age. Moreover, aged OPCs do not remain responsive to pro-differentiation signals, posing significant constraints on the effectiveness of remyelination therapies based on the enhancement of OPC differentiation. We show that this reduced regenerative capacity is associated with hallmarks of cellular ageing, including reduced metabolic function and increased DNA damage. We find that fasting or treatment with metformin can reverse these changes and restore the regenerative capacity of aged OPCs, improving remyelination in aged animals following white matter injury. Importantly, aged OPCs treated with metformin regain their responsiveness to pro-differentiation factors, suggesting a potential for synergistic effects of rejuvenation and pro-differentiation therapies. Our findings have direct implications for understanding oligodendrocyte regeneration failure with ageing and how it might be reversed therapeutically.