Mitophagy: The Cell's Self-Cleaning System for Damaged Mitochondria
Mitophagy — the selective autophagy of damaged or dysfunctional mitochondria — is the cell's primary quality control mechanism for maintaining a healthy, high-functioning mitochondrial network, preventing the accumulation of defective organelles that would otherwise generate excessive ROS, impair ATP synthesis, and trigger apoptotic signalling. This process, regulated primarily by the PINK1-Parkin pathway, detects mitochondria with collapsed membrane potential and tags them for lysosomal degradation, effectively recycling their molecular components and preventing the propagation of mitochondrial damage. Critically, mitophagy is impaired by the very conditions that cause mitochondrial damage in the first place — heavy metal accumulation, chronic inflammation, and insulin resistance — creating a vicious cycle in which toxic exposure both damages mitochondria and impairs the cell's capacity to remove them, a central mechanism in the pathogenesis of Parkinson's disease and other neurodegenerative conditions.
