Vitamin C stimulates sphingolipid production and markers of barrier formation in submerged human keratinocyte cultures.
Vitamin C stimulates sphingolipid production and markers of barrier formation in submerged human keratinocyte cultures.
复制标题
维生素 C 刺激水下人类角质形成细胞培养物中鞘脂的产生和屏障形成标记。
DOI：
10.1046/j.0022-202x.2001.01555.x
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
Holleran,WM
中科院分区：
文献类型：
--
作者：
Uchida,Y;Behne,M;Quiec,D;Elias,PM;Holleran,WM
人角质形成细胞在体外对多种刺激物有反应性分化，但神经酰胺的水平和谱都不能接近体内所见。当人角质形成细胞在空气-液体界面生长时，神经酰胺的产生增加，当维生素C加入到暴露于空气的器官型培养系统中时，神经酰胺含量发生改变（Ponecetal. JInvestDermatol 109：348，1997）。在这里，我们评估是否维生素C刺激鞘脂的生产在人类角质形成细胞独立的分化和空气暴露。当浸没时，人角质形成细胞在含1.2 mM钙和血清的培养基中生长9 d，维生素C（50 μg/ml），总脂质含量保持不变，但葡萄糖神经酰胺和神经酰胺含量增加。此外，选择的神经酰胺和葡糖神经酰胺种类：即，非羟基神经酰胺2以及α-和ω-羟基化鞘脂优先增加[神经酰胺4（6-羟基-酰基神经酰胺）、神经酰胺5（α-羟基神经酰胺）、神经酰胺6（4-羟基-α-羟基神经酰胺）和神经酰胺7（6-羟基-α-羟基神经酰胺）;以及酰基葡萄糖神经酰胺、葡萄糖神经酰胺-B和葡萄糖神经酰胺-D]，而神经酰胺1、神经酰胺3、葡萄糖神经酰胺-C和鞘磷脂保持不变。相应的神经酰胺和葡糖神经酰胺馏分的合成增强维生素C，部分原因是增加神经酰胺合成酶活性（超过2倍，p = 0.01），丝氨酸棕榈酰转移酶和葡糖神经酰胺合成酶活性保持不变。最后，维生素C刺激的鞘脂产生增加与存在具有成熟内部内容物的板层体、共价结合的ω-羟基神经酰胺的增加以及突出的角质细胞结合的脂质包膜的出现相关，而角质细胞包膜的形成没有变化。因此，在浸没的人角质形成细胞中，维生素C诱导鞘脂产生增加和渗透屏障结构标记物的增强。
Human keratinocytes differentiatein vitroin response to a variety of stimuli, but neither the levels nor the spectrum of ceramides approach those seenin 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 (Ponecet al.J Invest Dermatol109:348, 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 mMcalcium and serum-containing medium with vitamin C (50 µg 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 α- and ω-hydroxylated sphingolipids, increased preferentially [ceramide 4 (6-hydroxy-acylceramide), ceramide 5 (α-hydroxyceramide), ceramide 6 (4-hydroxy-α-hydroxyceramide), and ceramide 7 (6-hydroxy-α-hydroxyceramide); and acylglucosylceramide, 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 ω-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.