Mitochondrial changes and oxidative stress in a mouse model of Zellweger syndrome neuropathogenesis

- Expanded mitochondrial compartment in brains of mice lacking PEX13.
- Associated oxidative damage in brain.
- Indicators of mitochondrial oxidative stress in PEX13-deficient embryonic fibroblasts.
- Model of brain pathology involving a pronounced mitochondrial response to oxidative stress.

Zellweger syndrome (ZS) is a peroxisome biogenesis disorder that involves significant neuropathology, the molecular basis of which is still poorly understood. Using a mouse model of ZS with brain-restricted deficiency of the peroxisome biogenesis protein PEX13, we demonstrated an expanded and morphologically modified brain mitochondrial population. Cultured fibroblasts from PEX13-deficient mouse embryo displayed similar changes, as well as increased levels of mitochondrial superoxide and membrane depolarization; this phenotype was rescued by antioxidant treatment. Significant oxidative damage to neurons in brain was indicated by products of lipid and DNA oxidation. Similar overall changes were observed for glial cells. In toto, these findings suggest that mitochondrial oxidative stress and aberrant mitochondrial dynamics are associated with the neuropathology arising from PEX13 deficiency.