title: Structural identification of skin ceramides containing ω-hydroxy acyl chains using mass spectrometry.
abstract: The stratum corneum (SC) acts as a barrier that protects organisms against the environment and from transepidermal water loss. It consists of corneocytes embedded in a matrix of lipid metabolites (ceramides, cholesterol, and free fatty acids). Of these lipids, ceramides are sphingolipids consisting of sphingoid bases, linked to fatty acyl chains. Typical fatty acid acyl chains are composed of α-hydroxy fatty acids (A), esterified ω-hydroxy fatty acids (EO), non-hydroxy fatty acids (N), and ω-hydroxy fatty acids (O). Of these, O-type ceramides are ester-linked via their ω-hydroxyl group to proteins in the cornified envelope and can be released and extracted following mild alkaline hydrolysis. Tandem mass spectrometry (MS/MS) analysis of O-type ceramides using chip-based direct infusion nanoelectrospray-ion trap mass spectrometry generated the characteristic fragmentation pattern of both acyl and sphingoid units, suggesting that this method could be applied to the structural identification of O-type ceramides. Based on the MS/MS fragmentation patterns of O-type ceramides, comprehensive fragmentation schemes are proposed. In addition, we have also developed a method for identifying and profiling O-type ceramides in the mouse and guinea pig SC. This information may be used to identify O-type ceramides in the SC of animal skin.
authors.affiliation: BK21 Plus KNU Multi-Omics Based Creative Drug Research Team, College of Pharmacy and Research Institute of Pharmaceutical Sciences, Kyungpook National University, 80 Deahak-ro, Buk-gu, Daegu, 41566, Korea.
authors.forename: Zhexue
authors.initials: Z
authors.lastname: Wu
authors.affiliation: BK21 Plus KNU Multi-Omics Based Creative Drug Research Team, College of Pharmacy and Research Institute of Pharmaceutical Sciences, Kyungpook National University, 80 Deahak-ro, Buk-gu, Daegu, 41566, Korea.
authors.forename: Jong Cheol
authors.initials: JC
authors.lastname: Shon
authors.affiliation: Department of Medical Nutrition, Graduate School of East-West Medical Science, Kyung Hee University, 1732, Deogyeong-daero, Giheung-gu, Yongin, 17104, Korea.
authors.forename: Jong Yei
authors.initials: JY
authors.lastname: Kim
authors.affiliation: Department of Medical Nutrition, Graduate School of East-West Medical Science, Kyung Hee University, 1732, Deogyeong-daero, Giheung-gu, Yongin, 17104, Korea.
authors.forename: Yunhi
authors.initials: Y
authors.lastname: Cho
authors.affiliation: BK21 Plus KNU Multi-Omics Based Creative Drug Research Team, College of Pharmacy and Research Institute of Pharmaceutical Sciences, Kyungpook National University, 80 Deahak-ro, Buk-gu, Daegu, 41566, Korea. dstlkh@knu.ac.kr.
authors.forename: Kwang-Hyeon
authors.initials: KH
authors.lastname: Liu
mesh_terms: D000818:Animals; D002518:Ceramides / Q000032:analysis* / Q000737:chemistry*; D042926:Cytochrome P-450 CYP4A / Q000032:analysis* / Q000737:chemistry*; D006168:Guinea Pigs; D008297:Male; D051379:Mice; D008812:Mice, Hairless; D012867:Skin / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods
chemical_list: D002518:Ceramides; D042926:Cytochrome P-450 CYP4A
keywords: Guinea pig; Mass spectrometry; Mouse; O-type ceramide; Stratum corneum