Niemann-Pick type C disease: molecular mechanisms and potential therapeutic approaches

Cholesterol is an important lipid of mammalian cells. Its unique physicochemical properties modulate membrane behavior and it serves as the precursor for steroid hormones, oxysterols and vitamin D. Cholesterol is effluxed from the late endosomes/lysosomes via the concerted action of at least two distinct proteins: Niemann-Pick C (NPC)1 and NPC2. Mutations in these two proteins manifest as NPC disease - a very rare, usually fatal, autosomal, recessive, neurovisceral, lysosomal storage disorder. In this review, we discuss the possible mechanisms of action for NPC1 and NPC2 in mediating cholesterol efflux, as well as the different therapeutic approaches being pursued for the treatment of this lipid storage disorder.