Selective Recovery of Deranged Water-Holding Properties by Stratum Corneum Lipids

Sato

et al. 2009

209

150

This article is available online at http://www.jlr.org novo pathways, such as alterations of some species of the targeted lipidomes into others. Similar to common quantitative analyses using direct MS or LC-MS that need authentic standards together with internal ones, quantitative lipidomics may also require a standard set of all lipid species targeted, because each lipid species has a different molar response in MS detection except for special cases. However, it is practically impossible to obtain all authentic species, including not only different even straight carbon chains but also odd and/or branched ones. To overcome such limitations, lipidomics researchers have contrived a novel procedure to quantify lipidomes comprehensively. Han and Gross ( 3 ) proposed a quantitative method for analyzing triglyceride molecular species using direct MS, which involves a procedure to calculate response factors for species that are not available as authentic materials, based on differences of the responses in the numbers of total carbons and double bonds among the species. For quantitative determination of phospholipid molecular species, Koivusalo et al. ( 4 ) utilized the following parameAbstract One of the key challenges in lipidomics is to quantify lipidomes of interest, as it is practically impossible to collect all authentic materials covering the targeted lipidomes. For diverse ceramides (CER) in human stratum corneum (SC) that play important physicochemical roles in the skin, we developed a novel method for quantifi cation of the overall CER species by improving our previously reported profi ling technique using normal-phase liquid chromatography-electrospray ionization-mass spectrometry (NPLC-ESI-MS). The use of simultaneous selected ion monitoring measurement of as many as 182 kinds of molecular-related ions enables the highly sensitive detection of the overall CER species, as they can be analyzed in only one SC-stripped tape as small as 5 mm × 10 mm. To comprehensively quantify CERs, including those not available as authentic species, we designed a procedure to estimate their levels using relative responses of representative authentic species covering the species targeted, considering the systematic error based on intra-/inter-day analyses. The CER levels obtained by this method were comparable to those determined by conventional thin-layer chromatography (TLC), which guarantees the validity of this method. , ceramide class consisting of non-hydroxy fatty acids and 4-sphingenines; ESI, electrospray ionization; LOD, limit of detection; LOQ, limit of quantifi cation; NPLC, normal-phase liquid chromatography; RPLC, reversed-phase liquid chromatography; RSD, relative standard deviation; SC, stratum corneum; SIM, selected ion monitoring; S/N, signal to noise; TLC, thinlayer chromatography

Section: Chemicalsmentioning

confidence: 99%

Comprehensive quantification of ceramide species in human stratum corneum

Sato

et al. 2009

209

150

“…Compared with other human cells/tissues, the stratum corneum (SC) of human skin has extremely complex CERs consisting of fatty acid moieties (nonhydroxy, a-hydroxy, or ester-linked v-hydroxy) and sphingoid moieties (sphingosine, dihydrosphingosine, phytosphingosine, or 6-hydroxy-sphingosine) (5). CERs in human SC contribute to the formation of lamellae structures at intercellular spaces among the horny cells in the SC together with cholesterol and free fatty acids and play important physicochemical roles in determining cutaneous barrier and water-holding functions (6)(7)(8)(9). On the other hand, some scientists are interested in the dynamics of CER-related lipids in differentiated keratinocytes, where apoptosis occurs in the skin (10).…”

mentioning

confidence: 99%

Characterization of overall ceramide species in human stratum corneum

Shimizu

et al. 2008

299

259

Ceramides (CERs) in human stratum corneum (SC) play physicochemical roles in determining barrier and waterholding functions of the skin, and specific species might be closely related to the regulation of keratinization, together with other CER-related lipids. Structures of those diverse CER species, however, have not been comprehensively revealed. The aim of this study was to characterize overall CER species in the SC. First, we constructed 3D multi-mass chromatograms of the overall CER species, based on normalphase liquid chromatography (NPLC) connected to electrospray ionization-mass spectrometry (ESI-MS) using a gradient elution system and a postcolumn addition of a volatile saltcontaining polar solvent. The CERs targeted from the 3D chromatograms were structurally analyzed using NPLC-ESItandem mass spectrometry (MS/MS), which resulted in the identification of 342 CER species in the inner forearm SC. This led to the discovery of a new CER class consisting of ahydroxy fatty acid and dihydrosphingosine moieties, in addition to the 10 classes generally known. The results also revealed that those CERs contain long-chain (more than C 18 )-containing sphingoids and a great number of isobaric species. These novel results will contribute not only to physiochemical research on CERs in the SC but also to lipidomics approaches to CERs in the skin.-Masukawa, Y

“…sphingoid moiety . sphingoid-related ion Ceramides (CERs), which consist of a long amino alcoholic chain [sphingoid moiety (SPM)] covalently bound via an amide linkage to a fatty acid moiety (FAM), have important physicochemical roles in the barrier function and water-holding property of skin, together with other lipids in intercellular spaces of the stratum corneum (1,2). They also play key roles in signal transduction and cell regulation relevant to cell growth arrest, differentiation, senescence, apoptosis, and immune responses (3)(4)(5)(6)(7)(8)(9).…”

mentioning

confidence: 99%

Liquid chromatography-mass spectrometry for comprehensive profiling of ceramide molecules in human hair

Tsujimura

2006

Ceramides (CERs) play key roles in signal transduction and cell regulation, probably during the keratinization of human hair. Current methods using mass spectrometry (MS), however, are not sufficient to allow the comprehensive analysis of CER molecules, including isobaric and isomeric CERs. Therefore, a method for the comprehensive profiling of CERs was developed. The method developed is based on reversed-phase liquid chromatography (RPLC) coupled to atmospheric pressure chemical ionization (APCI)-MS. Comprehensive identification and profiling of CERs is achieved using two sets of multimass chromatograms obtained from two channel detections that monitor both molecular-related and sphingoid-related ions under two different in-source collision-induced dissociation conditions and using retention times obtained from RPLC. The application of this method revealed that human hair contains 73 species of CER molecules, which were all corroborated by structural analysis using tandem mass spectrometry. The results further revealed that the composition is characterized by predominant molecules consisting of even carbon atom-containing saturated/unsaturated nonhydroxy or a-hydroxy fatty acids and C 18 dihydrosphingosine, a minor but distinct content of isobaric/isomeric and odd chain-containing CERs. This successfully developed RPLC-APCI-MS technique allows the comprehensive profiling of CER molecules in hair for the investigation of their physicochemical and physiological roles.-Masukawa, Y., H. Tsujimura, and H. Narita. Liquid chromatography-mass spectrometry for comprehensive profiling of ceramide molecules in human hair. J. Lipid Res. 2006Res. . 47: 1559Res. -1571 Supplementary key words fatty acid moiety . identification . isobaric .