A lipidomic platform establishment for structural identification of skin ceramides with non-hydroxyacyl chains

The stratum corneum (SC) is the outermost layer of skin that functions as a barrier and protects against environmental influences and transepidermal water loss. Its unique morphology consists of keratin-enriched corneocytes embedded in a distinctive mixture of lipids containing mainly ceramides, free fatty acids, and cholesterol. Ceramides are sphingolipids consisting of sphingoid bases, which are linked to fatty acids by an amide bond. Typical sphingoid bases in the skin are composed of dihydrosphingosine (dS), sphingosine (S), phytosphingosine (P), and 6-hydroxysphingosine (H), and the fatty acid acyl chains are composed of non-hydroxy fatty acid (N), α-hydroxy fatty acid (A), ω-hydroxy fatty acid (O), and esterified ω-hydroxy fatty acid (E). The 16 ceramide classes include several combinations of sphingoid bases and fatty acid acyl chains. Among them, N-type ceramides are the most abundant in the SC. Mass spectrometry (MS)/MS analysis of N-type ceramides using chip-based direct infusion nanoelectrospray-ion trap mass spectrometry generated the characteristic fragmentation pattern of both acyl and sphingoid units, which could be applied to structural identification of ceramides. Based on the MS/MS fragmentation patterns of N-type ceramides, comprehensive fragmentation schemes were proposed. In addition, mass fragmentation patterns, which are specific to the sphingoid backbone of N-type ceramides, were found in higher m/z regions of tandem mass spectra. These characteristic and general fragmentation patterns were used to identify N-type ceramides in human SC. Based on established MS/MS fragmentation patterns of N-type ceramides, 52 ceramides (including different classes of NS, NdS, NP, and NH) were identified in human SC. The MS/MS fragmentation patterns of N-type ceramides were characterized by interpreting their product ion scan mass spectra. This information may be used to identify N-type ceramides in the SC of human, rat, and mouse skin.

[1]  T. Agner,et al.  Stratum corneum lipids, skin barrier function and filaggrin mutations in patients with atopic eczema , 2010, Allergy.

[2]  H. Nagahata,et al.  Quantities and types of ceramides and their relationships to physical properties of the horn covering the claws of clinically normal cows and cows with subclinical laminitis. , 2005, Canadian journal of veterinary research = Revue canadienne de recherche veterinaire.

[3]  Qing Shen,et al.  Shotgun lipidomics strategy for fast analysis of phospholipids in fisheries waste and its potential in species differentiation. , 2012, Journal of agricultural and food chemistry.

[4]  Takashi Kitahara,et al.  Characterization of overall ceramide species in human stratum corneums⃞s⃞ The online version of this article (available at http://www.jlr.org) contains supplementary data in the form of two figures and two tables. Published, JLR Papers in Press, March 23, 2008. , 2008, Journal of Lipid Research.

[5]  Xiaomei Yan,et al.  Metabonomics research of diabetic nephropathy and type 2 diabetes mellitus based on UPLC-oaTOF-MS system. , 2009, Analytica chimica acta.

[6]  A. Weerheim,et al.  Determination of stratum corneum lipid profile by tape stripping in combination with high-performance thin-layer chromatography , 2001, Archives of Dermatological Research.

[7]  S. Carelli,et al.  Ceramide composition of the psoriatic scale. , 1993, Biochimica et biophysica acta.

[8]  R. Neubert,et al.  Investigation of the Molecular Structure of the Human Stratum Corneum Ceramides [NP] and [EOS] by Mass Spectrometry , 2011, Skin Pharmacology and Physiology.

[9]  John Turk,et al.  Characterization of ceramides by low energy collisional-activated dissociation tandem mass spectrometry with negative-ion electrospray ionization , 2002, Journal of the American Society for Mass Spectrometry.

[10]  Stefan R Bornstein,et al.  Bottom-up shotgun lipidomics by higher energy collisional dissociation on LTQ Orbitrap mass spectrometers. , 2011, Analytical chemistry.

[11]  F. Bonte,et al.  Existence of a lipid gradient in the upper stratum corneum and its possible biological significance , 1997, Archives of Dermatological Research.

[12]  U. Hintze,et al.  Comparative investigation of human stratum corneum ceramides , 2001, Lipids.

[13]  R. Aebersold,et al.  Ceramide profiling of complex lipid mixtures by electrospray ionization mass spectrometry. , 1997, Analytical biochemistry.

[14]  A. Burlingame,et al.  Human stratum corneum lipids: characterization and regional variations. , 1983, Journal of lipid research.

[15]  R. Neubert,et al.  Separation and mass spectrometric characterization of covalently bound skin ceramides using LC/APCI-MS and Nano-ESI-MS/MS. , 2007, Journal of chromatography. B, Analytical technologies in the biomedical and life sciences.

[16]  Frank David,et al.  Profiling and characterizing skin ceramides using reversed-phase liquid chromatography-quadrupole time-of-flight mass spectrometry. , 2012, Analytical chemistry.

[17]  R. Neubert,et al.  Development and validation of LC/ESI-MS method for the detection and quantification of exogenous ceramide NP in stratum corneum and other layers of the skin. , 2012, Journal of pharmaceutical and biomedical analysis.

[18]  A. Kihara,et al.  Ceramide biosynthesis in keratinocyte and its role in skin function. , 2009, Biochimie.

[19]  W. Holleran,et al.  Epidermal sphingolipids: Metabolism, function, and roles in skin disorders , 2006, FEBS letters.

[20]  Hong Zhang,et al.  Tracking phospholipid profiling of muscle from Ctennopharyngodon idellus during storage by shotgun lipidomics. , 2011, Journal of agricultural and food chemistry.

[21]  Xianlin Han,et al.  Characterization and direct quantitation of ceramide molecular species from lipid extracts of biological samples by electrospray ionization tandem mass spectrometry. , 2002, Analytical biochemistry.

[22]  Xianlin Han,et al.  Alkaline methanolysis of lipid extracts extends shotgun lipidomics analyses to the low-abundance regime of cellular sphingolipids. , 2007, Analytical biochemistry.

[23]  R. Neubert,et al.  Liquid chromatography–electrospray mass spectrometry and tandem mass spectrometry of ceramides , 2000 .

[24]  Thomas Hankemeier,et al.  LC/MS analysis of stratum corneum lipids: ceramide profiling and discovery[S] , 2011, Journal of Lipid Research.

[25]  R. Neubert,et al.  Structural studies on ceramides by electrospray tandem mass spectrometry , 1998 .

[26]  Kim Ekroos,et al.  Long-term performance and stability of molecular shotgun lipidomic analysis of human plasma samples. , 2013, Analytical chemistry.