Lovastatin promotes myelin formation in NPC1 mutant oligodendrocytes

Niemann-Pick Type C (NPC) disease is a rare neurovisceral disorder caused by mutations of either NPC1 or NPC2 gene and characterized by defective intracellular transport of cholesterol and glycosphingolipids, leading to neuron loss and myelin aberration in the central nervous system. In this study, by comparing protein expression in the cortical white matter tracts from mice at different postnatal days, we identified that in the NPC1 mutant (NPC1^-/-) mice, the onset of myelination is delayed and the amount of the major myelin protein MBP and PLP, and oligodendrocyte regulatory factor Olig1 and Olig2, but not NG2 and Sox10, decreased significantly, suggesting a disruption of oligodendrocyte differentiation. Furthermore, in in vitro oligodendrocyte cultivation, NPC1^-/- oligodendrocytes showed less response to the stimulation of neuron-conditioned medium (CdM), indicating a defect of oligodendrocyte per se. Interestingly, lovastatin restores the number of mature myelin-forming oligodendrocytes by increasing Olig1 and Olig2 expressions. Our data suggest a potential strategy for improving myelination using lovastatin in NPC disease.