M6A RNA Methylation-Mediated TUG1 Stability Maintains Mitochondrial Homeostasis during Kidney Aging by Epigenetically Regulating PGC1-α Expression

Background: Aging is a significant risk factor for the increased incidence of acute kidney injury and chronic kidney disease, posing significant challenges to global public health. The role of N6-methyladenosine (m6A) in the development of chronic kidney disease has been reported, but the regulatory mechanism of m6A in kidney aging remains unclear. Results: In this study, we identified a long noncoding RNA (lncRNA), called taurine up-regulated 1 (TUG1), which exhibited a significantly decreased level of m6A modification in human aged kidney through the m6A-lncRNA epitranscriptome microarray. Bioinformatics analysis and machine learning predicted that TUG1 had potentially strong interaction with PGC1-α. RNA immunoprecipitation and chromatin immunoprecipitation analysis showed that TUG1 promoted proliferator-activated receptor γ coactivator-1α (PGC1-α) expression by directly interacting with its TUG-1 binding element region, thereby impacting mitochondrial quality control (MQC), cellular senescence, and renal fibrosis. Silencing the RNA m6A methylase methyltransferase 14 (METTL14) or the reader protein insulin-like growth factor 2 mRNA-binding proteins (IGF2BP2) resulted in the weakened stability of lncRNA TUG1, contributing to an imbalance in MQC. Conclusion: Our study demonstrated that the m6A modification and stability of TUG1 were mediated by METTL14 in an IGF2BP2-dependent manner, and modulate the mitochondrial homeostasis in kidney aging by direct targeting PGC-1α. These findings provide a new perspective on potential therapeutic targets for kidney aging. Antioxid. Redox Signal. 41, 993-1013.