6-Hydroxy-4-sphingenine in human epidermal ceramides.

Robson, Kristi J.; Stewart, Mary Ellen; Michelsen, Silke; Lazo, Noel D.; Downing, Donald T.

doi:10.1016/s0022-2275(20)39952-1

Cited by 248 publications

(74 citation statements)

References 19 publications

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“…However, ceramides 4 and 5 are chemically identical except for the chain lengths of the fatty acid moieties, and ceramide 6a apparently was an artifact (7), so there actually are five classes of extractable ceramides in pig stratum corneum, four textbook ceramides plus ceramide 1. With the original discovery of 6-hydroxysphingosine-based ceramides in human skin, the human extractable ceramides were renumbered 1 through 7, with the new ones being ceramide 4, which is analogous to ceramide 1 in having an acylated -hydroxyacid, and ceramide 7, which has an ␣ -hydroxyacid (5). The ceramide referred to as ceramide 4/5 in pig was renumbered ceramide 5.…”

Section: Discussionmentioning

confidence: 99%

“…Two ceramides were isolated: the new ceramide and the most polar ceramide, which is known to consist of 6-hydroxysphingosine combined with an ␣ -hydroxy fatty acid (5). The latter was needed as a reference ceramide for NMR analysis.…”

Section: Isolation Of Ceramidesmentioning

confidence: 99%

“…Human stratum corneum ceramides were initially thought to be similar to those in pig (3), except for the existence of a second protein-bound ceramide having an -hydroxyacid and an additional hydroxyl group on the sphingoid base (4). When we found that this second proteinbound ceramide contains a previously unknown sphingoid moiety, 6-hydroxy-4-sphingenine (6-hydroxysphingosine), it led to the discovery of two additional extractable ceramides in human epidermis (5). One of these previously reported extractable ceramides is analogous to the bound ceramide in consisting of 6-hydroxysphingosine bound to an -hydroxyacid, except that the -hydroxyl group is esterified to a fatty acid rather than to protein.…”

mentioning

confidence: 95%

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A new 6-hydroxy-4-sphingenine-containing ceramide in human skin

Stewart

Downing

1999

Journal of Lipid Research

103

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A new ceramide consisting of 6-hydroxysphingosine linked to a non-hydroxyacid was found in human epidermal lipid. This ceramide was sought because its fatty acid and sphingoid moieties are present in other combinations in human epidermal ceramides. To isolate the new ceramide, the mixture of ceramides in human epidermal lipid was first separated into fractions by thin-layer chromatography (TLC), and then each fraction was further purified by TLC after acetylation of all hydroxyl groups. TLC after acetylation revealed that one of the fractions isolated in the first TLC step contained two components, namely, the ceramide consisting of sphingosine linked to an ␣hydroxyacid and an unknown ceramide. The new ceramide constituted about 9% of the total ceramides, and was shown by NMR spectroscopy to be N-acyl-6-hydroxysphingosine. -Stewart, M. E., and D. T. Downing. A new 6-hydroxy-4-sphingenine-containing ceramide in human skin.

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Section: Discussionmentioning

confidence: 99%

Section: Isolation Of Ceramidesmentioning

confidence: 99%

mentioning

confidence: 95%

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A new 6-hydroxy-4-sphingenine-containing ceramide in human skin

Stewart

Downing

1999

Journal of Lipid Research

103

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“…It should be noted that the bound lipids of human stratum corneum contain two classes of hydroxyceramides. About 60% of the hydroxyceramides contain sphingosine, as in pig, and the other 40% contain 6-hydroxysphingosine, a type of sphingosine that has only been found in humans (12). 6-Hydroxysphingosine is also found in three classes of free ceramides of human skin.…”

Section: Structure Of the Corneocyte Lipid Envelopementioning

confidence: 99%

“…6-Hydroxysphingosine is also found in three classes of free ceramides of human skin. The fatty acid moieties of these three classes are: nonhydroxyacids, ␣ -hydroxyacids, or -hydroxyacids having a nonhydroxyacid esterified to the -hydroxyl group (12,13).…”

Section: Structure Of the Corneocyte Lipid Envelopementioning

confidence: 99%

The ω-hydroxyceramides of pig epidermis are attached to corneocytes solely through ω-hydroxyl groups

Stewart

Downing

2001

Journal of Lipid Research

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The cornified outer cells of mammalian epidermis possess a monolayer of -hydroxyceramides that are ester-linked to the exterior of a cross-linked protein envelope. In the present study, conclusive evidence was sought on which of the ceramide hydroxyl groups are involved in the linkage to protein. This was obtained by derivatizing all free hydroxyl groups in isolated solvent-extracted porcine stratum corneum using triisopropylsilyl (TIPS) chloride in pyridine in the presence of silver nitrate. After an 18-h reaction, the tissue was recovered, rinsed, and the derivatized ceramides were then released from protein linkage by hydrolysis with 1M KOH in 95% methanol. This gave a single ceramide product that was shown by nuclear magnetic resonance to contain two triisopropyl groups. Acetylation of the product using acetic anhydride in pyridine resulted in a downfield shift of the NMR signal for the -methylene protons, showing that it was the -hydroxyl that was free in the initial reaction product, and subsequently was acetylated. These results show that all of the -hydroxyceramides of corneocyte lipid envelopes are attached to protein through their -hydroxyl groups. -Stewart, M. E., and D. T. Downing. The -hydroxyceramides of pig epidermis are attached to corneocytes solely through -hydroxyl groups.

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