Analysis of phospholipid molecular species in brains from patients with infantile and juvenile neuronal‐ceroid lipofuscinosis using liquid chromatography‐electrospray ionization mass spectrometry

Abstract

Phospholipids (PL) in cerebral cortex from patients with infantile (INCL or CLN1) and juvenile (JNCL or CLN3) forms of neuronal ceroid-lipofuscinosis (NCL) and controls were analysed by normal phase HPLC and on-line electrospray ionization ion-trap mass spectrometric detection (LC-ESI-MS). The method provided quantitative data on numerous molecular species of different PL classes, which are not achieved by using the conventional chromatographic methods. Compared with the controls, the INCL brains contained proportionally more phosphatidylcholine (PC), and less phosphatidylethanolamine (PE) and phosphatidylserine (PS). Different molecular species of PC, PE, PS, phosphatidylinositol and sphingomyelin were quantified using multiple internal PL standards that differed in fatty acyl chain length and thus allowed correction for chain length dependency of instrument response. In INCL cortex, which had lost 65% of the normal PL content, the proportions of polyunsaturated molecular species, especially the PS and PE that contained docosahexaenoic acid (22:6n-3), were dramatically decreased. The membranes may have adapted to this alteration by increasing the proportions of PL molecules substituted with monounsaturated and short-chain fatty acids. Lysobisphosphatidic acid was highly elevated in the INCL brain and consisted mostly of polyunsaturated species. It is possible that changes in the composition of PL membranes accelerate progression of INCL by altering signalling and membrane trafficking in neurons.

Bis(monoacylglycero)phosphate: a secondary storage lipid in the gangliosidoses

“…Although BMP comprises a small portion of total phospholipids in normal tissues, BMP levels increase in many LSDs, such as Niemann-Pick, neuronal ceroid lipofuscinoses, mucopolysaccharidosis (MPS I and II), Fabry disease, and Gaucher disease ( 16,17,(19)(20)(21)(22)(23)(24)(25). However, no detailed studies of BMP content and composition have been conducted in the brains of ganglioside storage diseases ( 28 ).…”

Electrospray Ionization Mass Spectrometry and Exogenous Heavy Isotope-labeled Lipid Species Provide Detailed Information on Aminophospholipid Acyl Chain Remodeling

“…S-BEL and R-BEL were from Cayman Europe (Tallinn, Estonia) and the solvents (HPLC-grade) from Merck. The PE and PS species with a deuterium-labeled head group were synthesized from corresponding phosphatidylcholine species and D 4 -ethanolamine or D 3 -serine, respectively, using phospholipase D-mediated transphosphatidylation as described previously for unlabeled lipids (27) except that the reaction volume was reduced 5-fold. The products were purified by normal phase HPLC (28), and their purity was confirmed by mass spectrometry.…”

PNPLA3 mediates hepatocyte triacylglycerol remodeling

“…Immediately before MS, 1% NH 4 OH was added along with an internal standard mixture containing polar and neutral lipid species. The samples were infused into an ion trap ESI mass spectrometer (Esquire-LC, BrukerFranzen Analytik, Bremen, Germany) and spectra recorded by employing both positive and negative ionization mode in the range of m / z 500-1,000 ( 26 ( 27 ). In addition, FA composition of total lipids was determined by GC as detailed in Käkelä et al ( 28 ).…”