m6A-Mediated epitranscriptomic control of mitochondrial dysfunction in neurodegeneration.

Mitochondrial dysfunction is a common pathology of neurodegenerative diseases, which contributes to neuronal vulnerability via excessive oxidative stress, impaired bioenergetics, and dysregulated apoptosis. Emerging studies highlighted the critical role of epitranscriptomic RNA modifications, particularly N6-methyladenosine (m6A), in mitochondrial gene expression regulation and cellular stress responses. m6A modifications are installed by methyltransferases ("writers," METTL3/METTL14), recognized by reader proteins (YTH domain family proteins, IGF2BPs), and removed by demethylases ("erasers," FTO, ALKBH5), collectively orchestrating mRNA splicing, localization, stability, and translation. Recent evidence demonstrates that m6A modifications modulate both nuclear-encoded and mitochondrially encoded transcripts and regulate key mitochondrial processes, including fission/fusion dynamics, oxidative phosphorylation, mitophagy, and apoptosis. Dysregulation of m6A machinery disrupts mitochondrial homeostasis, exacerbates oxidative stress and neuroinflammation, and promotes neuronal loss. Importantly, pharmacological or genetic modulation of m6A regulators can restore mitochondrial function, inhibit caspase activation, and dampen pro-inflammatory signaling, underscoring their therapeutic potential. This review consolidates current insights into mitochondrial epitranscriptomics, emphasizing how m6A modifications act as central regulators of mitochondrial stress responses and neurodegeneration.