Age-associated decline of MondoA drives cellular senescence through impaired autophagy and mitochondrial homeostasis

Accumulation of senescent cells affects organismal aging and the prevalence of age-associated disease. Emerging evidence suggests that activation of autophagy protects against age-associated diseases and promotes longevity, but the roles and regulatory mechanisms of autophagy in cellular senescence are not well understood. Here we identified the transcription factor, MondoA, as a novel regulator of cellular senescence, autophagy and mitochondrial homeostasis. MondoA protected against cellular senescence by activating autophagy partly through the suppression of an autophagy negative regulator, Rubicon. In addition, we identified peroxiredoxin 3 (Prdx3) as another downstream regulator of MondoA essential for mitochondrial homeostasis and autophagy. Rubicon and Prdx3 worked independently to regulate senescence. Furthermore, we found that MondoA knockout mice had exacerbated senescence during ischemic acute kidney injury (AKI), and a decrease of MondoA in the nucleus was correlated with human aging and ischemic AKI. Our results suggest that retaining MondoA activity protects from senescence and age-associated disease. Overall design: MondoA or Mlx knockdown treated with or without doxorubicin (DXR) in RPE-1 cells