Lipidomics

The full complement of various chemically distinct covalent entities in cellular lipids is referred to as the lipidome. Lipidomics is the field of study that 

Another approach, data-dependent acquisition (jyDPi)-driven lipid profiling [67], analyzes an unfractionated sample using a Q-TOF instrument. The lipid extract is infused directly into a nanospray chip ion source of a Q-TOF 

Lipids occur widely in nature. For examples, phospholipids are the main building blocks of biological membranes. Lipids exist in a variety of distinct forms, such as fatty acids, acylglycerols, phospholipids, sphingomyelins, glycosphingolipids, gangliosides, steroids, bile acids, prostaglandins, and leukotrienes. Some of lipids are structurally simple molecules, but others are complex molecules. Many are amphiphilic compounds. 

Phospholipids are structurally diverse amphiphilic molecules. A complete characterization of phospholipids requires the identity of fatty acyl groups and the polar head group. FAB, ESI, and MALDl, either alone or in conjunction with CID-MS/MS, have been highly successful in analyzing phospholipids. CID-MS/MS of the lithiated adducts of phospholipids, especially, can reveal the identity of the fatty acyl groups. The neutral-loss and precursor-ion scans of specific polar head group marker ions are useful in identifying phospholipids in complex lipid mixtures. 

Structurally, glycosphingolipids and gangliosides are distinct from other classes of lipids they are made of a hydrophobic ceramide lipid tail to which an oligosaccharide head group is attached. Characterization of glycosphingolipids and gangliosides is achieved by CID-MS/MS of the FAB-, ESI-, and MALDI-produced [M - - H]+ and [M — H] ions. Structural information on ceramide and carbohydrate portions can be also derived. 

As spokeslipid, let me tell you that we are way too complicated. You have no chance of analyzing us, with our hydra heads and medusa s hair tails  

The strategy in focused lipidomics is to utilize specific fragment ions, obtained via product, precursor, or neutral loss scanning (Section 3.3.3.1), to categorize all lipids in a particular class. Specificity can be unproved with appropriate chromatographic separation, such as reversed- and normal- (hydrophilic liquid interaction chromatography (HILIC)) phase LC, as well as GC. 

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FATP5 KO mice have been characterized in two studies focusing on the role of FATP5 in hepatic lipid and bile metabolism. LCFA uptake in primary hepato-cytes isolated from FATP5 KO mice was reduced by 50% and hepatic lipid content in the KO mice was significantly reduced despite an increased fatty acid de novo biosynthesis. Detailed analysis of the hepatic lipidome of FATP5 KO mice revealed significant... 

Schmitz G, Liebisch G, Langmann T (2006) Lipidomic strategies to study structural and functional defects of ABC-transpoiters in cellular lipid tr afficking. FEBS Lett 9 5 80(23) 5597-610. Review... 

Volume 432. Lipidomics and Bioactive Lipids Mass-Spectrometry—Based Lipid Analysis (in preparation)... 

Shevchenko A, Simons K (2010) Lipidomics coming to grips with lipid diversity. Nat Rev Mol Cell Bio 11 593-598... 

Han, X. and Gross, R.W. Global analysis of cellular lip-idomes directly from crude biological samples by ESI mass spectrometry a bridge to lipidomics. /. Lipid Res. 44 1071-1079, 2003. 

The knowledge evolving from lipidomic neurobiology will be potentiated by multidisciplinary approaches, such as multiphoton confocal analysis 588... 

D1 (10,17S-docosatriene) from DHA using tandem liquid chromatography-photodiode array-electrospray ionization-tandem mass spectrometry (LC-PDA-ESI-MS-MS)-based lipidomic analysis have been documented in ischemic brain [4] and retinal pigment epithelium [5], This new lipid is called neuroprotectin D1 (1) because of its neuro-protectiveproperties in brain ischemia-reperfusion [4] and in oxidative stress-challenged retinal pigment epithelial cells [5] (2) because of its potent ability to inactivate proapoptotic signaling (see apoptosis, Ch. 35) [5] and (3) because it is the first identified neuroprotective mediator derived from DHA. 

Tan B, Bradshaw HB, Rimmerman N et al. Targeted lipidomics Discovery of new fatty acyl amides. AAPS Journal 8, E461-E465, 2006. 

Adibhatla R. M., Hatcher J. F., and Dempsey R. J. (2006). Lipids and lipidomics in brain injury and diseases. AAPS J. 8 E314-E321. 

Bowers-Gentry R. C., Deems R. A., Harkewicz R., and Dennis E. A. (2006). Eicosanoid lipidomics. In Feng L. and Prestwich G. D. (eds.), Functional Lipidomics. CRC Press-Taylor Francis Group, Boca Raton, pp. 79-100. 

Serhan C. N. (2005a). Mediator lipidomics. Prostaglandins Other Lipid Mediat. 77 4-14. 

Serhan C. N., Hong S., and Lu Y. (2006). Lipid mediator informatics-lipidomics Novel pathways in mapping resolution. AAPS J. 8 E284-E297. 

Watson A. D. (2006). Lipidomics a global approach to lipid analysis in biological systems. J. Lipid Res. 47 2101-2111. 

X. L. Han and R. W. Gross, Shotgun lipidomics Electrospray ionization mass spectrometric analysis and quantitation of cellular lipidomes directly from crude extracts of biological samples, Mass Spectrom. Rev., 24 (2005) 367-412. 

X. L. Han and H. Cheng, Characterization and direct quantitation of cerebroside molecular species from lipid extracts by shotgun lipidomics, J. Lipid Res., 46 (2005) 163-175. 

Volume 433. Lipidomics and Bioactive Lipids Specialized Analytical Methods and... 

Volume 434. Lipidomics and Bioactive Lipids Lipids and Cell Signaling Edited by H. Alex Brown... 

The lipidome profile of mice liver homogenates of free cholesterol, low cholesterol, and high cholesterol diets showed the influence between dietary cholesterol intake and atherosclerosis (17). To get individual metabolite fingerprints, they measured near 300 metabolites such as di- and triglycerides, phosphatidylcholines, LPCs, and cholesterol esters in plasma samples by LC-MS/MS. It was observed that when dietary cholesterol intake was increased, the liver compensated for elevations in plasma cholesterol by adjusting metabolic and transport processes related to lipid metabolism, which... 

Advanced analytical techniques, particularly mass spectrometry (MS), often combined with liquid chromatography (LC) or gas chromatography (GC), are requisite for lipid analysis and they have played the crucial role in the emergence as well as the progresses of lipidomics. MS is the principal choice for the lipid analysis, particularly using electrospray ionization (ESI) and sometimes also atmospheric pressure chemical ionization or laser-based MS methods for surface analysis. The MS-based techniques are the best choice for lipidomics due to their superior sensitivity and molecular specificity, and because they provide the ability to resolve the extensive compositional and structural diversity of lipids in biological systems. 

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