LIPIDOMICS OF HUMAN SKIN FIBROBLASTS IN NEIMANN-PICK DISEASE TYPE C

Abstract

Neimann-Pick Disease type C is a hereditary lysosomal storage disease due to mutations of the NPC1 or NPC2 genes. The products of these genes encodes for components of a lysosomal machinery that transport different kinds of lipids across the lysosomal membrane. The main abnormalities of NPC1 de ciency phenotype is the accumulation of free cholesterol (FC) and sphingolipids (GL) in brain, liver and other organs cells. Neurodegeneration and hepato-splenomegaly are common ndings. The NPC disease, in his severe onset, leads to a precocious exitus, though the inhibition of glyco-SL synthesis by miglustat has shown some clinical bene t. Recently the physiopathological mechanism has been partly elucidated, being the rst step represented by the disruption of lysosomal calcium homeostasis due to sphinganine accumulation. NPC1 Human skin broblasts (HSF) accumulate FC, as shown by lipin staining. The exact composition of the whole NPC1-HSF lipidome is currently poor characterized. We developed a fully automated method to resolve individual lipids species from cells extracts by LC-ESI-MS in a Thermo Scienti c Q exactive LC MS/MS apparatus. This methods allowed to obtain relative quanti cation and identi cation of more than ve hundreds of different compounds using both positive and negative ionization modes. We used this method to compare the lipidome pro ling of free living NPC-HSF with healthy control-HSF. Hopefully the results will add useful information to support the understanding of the NPC pathophysiology.