Vitamin E Dietary Supplementation Improves Neurological Symptoms and Decreases c-Abl/p73 Activation in Niemann-Pick C Mice

Niemann-Pick C (NPC) disease is a fatal neurodegenerative disorder characterized by the accumulation of free cholesterol in lysosomes. We have previously reported that oxidative stress is the main upstream stimulus activating the proapoptotic c-Abl/p73 pathway in NPC neurons. We have also observed accumulation of vitamin E in NPC lysosomes, which could lead to a potential decrease of its bioavailability. Our aim was to determine if dietary vitamin E supplementation could improve NPC disease in mice. NPC mice received an alpha-tocopherol (alpha-TOH) supplemented diet and neurological symptoms, survival, Purkinje cell loss, alpha-TOH and nitrotyrosine levels, astrogliosis, and the c-Abl/p73 pathway functions were evaluated. In addition, the effect of alpha-TOH on the c-Abl/p73 pathway was evaluated in an in vitro NPC neuron model. The alpha-TOH rich diet delayed loss of weight, improved coordination and locomotor function and increased the survival of NPC mice. We found increased Purkinje neurons and alpha-TOH levels and reduced astrogliosis, nitrotyrosine and phosphorylated p73 in cerebellum. A decrease of c-Abl/p73 activation was also observed in the in vitro NPC neurons treated with alpha-TOH. In conclusion, our results show that vitamin E can delay neurodegeneration in NPC mice and suggest that its supplementation in the diet could be useful for the treatment of NPC patients.