It shows signs of failure because it is missing another key molecule in mitochondrial quality control. (source.wustl.edu)
Interestingly, these changes are related to the so - called PINK1 - Parkin pathway that is responsible for the mitochondrial quality control system and implicated in Parkinson's disease. (sciencedaily.com)
We have recently proposed an interplay between the myokine Fgf21 and the mitochondrial quality control pathways that greatly contributes to a pro-senescence metabolic shift. (inmg.fr)