Lipidomes

The lipidome is the complete set of lipids present in a given biological system, such as a cell, tissue, organism, or environmental sample. Lipids are central to membrane structure, energy storage, and signaling, and the lipidome reflects physiological state, development, diet, and disease. Lipidomes are highly diverse, comprising thousands of distinct lipid species organized into major families that differ in headgroups, backbones, and acyl substituents.

Common lipid classes include glycerophospholipids (phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, phosphatidylserine, among others); sphingolipids (ceramides, sphingomyelins, glycosphingolipids); glycerolipids (triacylglycerols, diacylglycerols); sterols (cholesterol and cholesteryl esters); fatty acyls; prenol lipids; and saccharolipids. Within each class, species vary by fatty acyl chain length, degree of unsaturation, and other structural features, creating extensive combinatorial diversity. Lipidomics seeks to characterize and quantify this diversity in a given sample.

Analytical approaches in lipidomics use mass spectrometry in targeted and untargeted modes, often coupled with liquid chromatography. Typical workflows involve lipid extraction (Bligh and Dyer or Folch methods), separation, internal standards, and data processing. Challenges include distinguishing isomeric species, achieving wide dynamic range, and harmonizing data across studies.

Applications span basic biology and medicine, including mapping lipid metabolism, studying membrane biophysics and signaling, and understanding disease processes. Lipidome alterations are associated with obesity, diabetes, cardiovascular disease, neurodegenerative disorders, and cancer. Public resources such as LIPID MAPS, LipidomicsDB, and LipidBank support standardized nomenclature, classification, and data sharing for the research community.