title: Extensive characterization of human tear fluid collected using different techniques unravels the presence of novel lipid amphiphiles.
abstract: The tear film covers the anterior eye and the precise balance of its various constituting components is critical for maintaining ocular health. The composition of the tear film amphiphilic lipid sublayer, in particular, has largely remained a matter of contention due to the limiting concentrations of these lipid amphiphiles in tears that render their detection and accurate quantitation tedious. Using systematic and sensitive lipidomic approaches, we validated different tear collection techniques and report the most comprehensive human tear lipidome to date; comprising more than 600 lipid species from 17 major lipid classes. Our study confers novel insights to the compositional details of the existent tear film model, in particular the disputable amphiphilic lipid sublayer constituents, by demonstrating the presence of cholesteryl sulfate, O-acyl-ω-hydroxyfatty acids, and various sphingolipids and phospholipids in tears. The discovery and quantitation of the relative abundance of various tear lipid amphiphiles reported herein are expected to have a profound impact on the current understanding of the existent human tear film model.
authors.affiliation: State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Sin Man
authors.initials: SM
authors.lastname: Lam
authors.forename: Louis
authors.initials: L
authors.lastname: Tong
authors.forename: Xinrui
authors.initials: X
authors.lastname: Duan
authors.forename: Andrea
authors.initials: A
authors.lastname: Petznick
authors.forename: Markus R
authors.initials: MR
authors.lastname: Wenk
authors.forename: Guanghou
authors.initials: G
authors.lastname: Shui
mesh_terms: D002851:Chromatography, High Pressure Liquid; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008055:Lipids / Q000032:analysis* / Q000737:chemistry* / Q000302:isolation & purification; D013058:Mass Spectrometry; D008537:Meibomian Glands / Q000737:chemistry; D011934:Reagent Strips / Q000737:chemistry; D015203:Reproducibility of Results; D013666:Tears / Q000737:chemistry*; D013997:Time Factors
chemical_list: D008055:Lipids; D011934:Reagent Strips
keywords: O-acyl-ω-hydroxy fatty acids; cholesteryl sulfates; dry eye syndrome; lipidomics; mass spectrometry; meibum; tear lipidome