Coenzyme Q10 deficiency is classically associated with impaired mitochondrial respiratory chain function, altered ATP production, and oxidative stress. However, emerging evidence suggests that mitochondrial dysfunction may also have important secondary effects on lysosomal biology. Lysosomes require an acidic lumen for optimal degradative activity, and disruption of lysosomal pH may compromise autophagy, macromolecular recycling, and cellular homeostasis.

This presentation will introduce the relationship between CoQ10 deficiency and lysosomal dysfunction, building on previous work showing altered lysosomal acidification in a neuronal model of CoQ10 deficiency. The talk will then present new flow cytometry data using a DQ-BSA assay to investigate whether these lysosomal pH changes are associated with altered lysosomal proteolytic function following PABA-induced CoQ10 deficiency. Together, the work explores whether lysosomal impairment may represent an underappreciated contributor to pathology in primary mitochondrial disease.