Ketogenic diet ameliorates axonal defects and promotes myelination in Pelizaeus-Merzbacher disease

Area of Science:

• Neuroscience
• Biochemistry
• Genetics

Background:

• Pelizaeus-Merzbacher disease (PMD) is a fatal leukodystrophy characterized by impaired myelination.
• Previous studies suggested cholesterol supplementation could promote myelin growth in PMD models with compromised blood-brain barriers.

Purpose of the Study:

• To investigate the efficacy of dietary cholesterol and ketogenic diets in treating Pelizaeus-Merzbacher disease.
• To explore therapeutic strategies that can bypass the blood-brain barrier for CNS myelin repair.

Main Methods:

• Assessed the impact of dietary cholesterol in two PMD patients.
• Utilized a PMD mouse model with intact blood-brain barrier integrity.
• Administered a high-fat/low-carbohydrate ketogenic diet to the PMD mouse model.
• Evaluated oligodendrocyte integrity, CNS myelination, axonal degeneration, and motor function recovery.

Main Results:

• Dietary cholesterol did not significantly improve hypomyelination in PMD patients, likely due to an intact blood-brain barrier.
• Ketogenic diet restored oligodendrocyte integrity and increased CNS myelination in the PMD mouse model.
• The ketogenic diet ameliorated axonal degeneration and normalized motor functions in affected mice.
• Ketogenic diet also facilitated remyelination and attenuated axon damage in an adult remyelination paradigm.

Conclusions:

• Dietary cholesterol is ineffective for PMD treatment when the blood-brain barrier is intact.
• Ketogenic diets represent a promising therapeutic strategy for PMD by promoting myelination and neuroprotection.
• Lipid-based therapies, such as ketone bodies, can potentially treat myelin diseases by circumventing the blood-brain barrier.