Vitamin C stimulates sphingolipid production and markers of barrier formation in submerged human keratinocyte cultures

JOURNAL OF INVESTIGATIVE DERMATOLOGY

卷:117

Article

Uchida, Y ; Behne, M ; Quiec, D ; Elias, PM ; Holleran, WM

关键词: epidermis;    ceramide;    glucosylceramide;    keratinocyte;    vitamin C;   

DOI  :  10.1046/j.0022-202x.2001.01555.x

来源: Elsevier

【 摘 要 】

Human keratinocytes differentiate in vitro in response to a variety of stimuli, but neither the levels nor the spectrum of ceramides approach those seen in vivo. Ceramide production increases when human keratinocytes are grown at an air-liquid interface, and alterations in ceramide content occur when vitamin C is added to air-exposed, organotypic culture systems (Ponec et al. J Invest Dermatol 109:348, 1997). Here, we assessed whether vitamin C stimulates sphingolipid production in human keratinocytes independent of differentiation and air exposure. When submerged, human keratinocytes were grown in 1.2 mm calcium and serum-containing medium with vitamin C (50 mug per ml) for 9 d, total lipid content remained unchanged, but both glucosylceramide and ceramide content increased. Moreover, selected ceramide and glucosylceramide species: i.e., nonhydroxy ceramide 2 and both alpha- and omega -hydroxylated sphingolipids, increased preferentially [ceramide 4 (6-hydroxy-acylceramide), ceramide 5 (alpha -hydroxyceramide), ceramide 6 (4-hydroxy-alpha -hydroxyceramide), and ceramide 7 (6-hydroxy-alpha -hydroxyceramide); and acylglucosyl-ceramide, glucosylceramide-B, and glucosylceramide-D], whereas ceramide 1, ceramide 3, glucosylceramide-C, and sphingomyelin remained unchanged. Synthesis of the corresponding ceramide and glucosylceramide fractions was enhanced by vitamin C, attributable, in part, to increased ceramide synthase activity (over 2-fold, p=0.01); both serine palmitoyltransferase and glucosylceramide synthase activities remained unaltered. Finally, increased vitamin C-stimulated sphingolipid production correlated with the presence of lamellar bodies with mature internal contents, an increase in covalently bound omega -hydroxyceramide, and the appearance of prominent, corneocyte-bound lipid envelopes, whereas cornified envelope formation was unchanged. Thus, in submerged human keratinocytes, vitamin C induces both increased sphingolipid production and enhancement of permeability barrier structural markers.

【 授权许可】

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