J Drugs Dermatol. 2022 Jan 1;21(1):77-85. doi: 10.36849/JDD.2022.6331.
The epidermal stratum corneum (SC) lipid matrix, principally consisting of an equimolar ratio of ceramides, free fatty acids, and cholesterol, plays a crucial role in maintaining proper skin barrier function. Conditions which impair barrier integrity, such as in atopic dermatitis, correlate with the alternation of key ceramide subclasses and reduced chain length of acyl moieties. However, there is limited knowledge about the impact of unprotected repeat sun exposure on the skin lipid composition, especially ceramide profiles.This study investigated the effects of ultraviolet (UV) radiation on the ceramide profile using both an ex vivo skin and a clinical model. Lipidomic analysis of UV-exposed skin showed shifts to the composition of ceramide subclasses essential in repairing and strengthening the SC barrier (including CER1[EOS], CER3[NP], and CER6[AP]) and reduced very long-chain acyl moieties. Gene expression analysis and immunohistochemical staining of key enzymes (aSMase, DES1, CerS5, CerS3) suggested that lipid alterations can be attributed to changes within the ceramide biosynthesis process. Topical application of ceramide-containing suncare products help maintain SC-essential ceramide subclasses and proper ceramide chain length, demonstrating the importance of proper photoprotection to maintain healthy skin barrier and ceramide quality during daily sun exposure. J Drugs Dermatol. 2022;21(1):77-85. doi:10.36849/JDD.6331.
表皮角质层（SC）脂质基质主要由神经酰胺、游离脂肪酸和胆固醇以等摩尔比例组成，对维持皮肤屏障功能至关重要。破坏屏障完整性的条件，如特应性皮炎，与关键神经酰胺亚类的改变和酰基链长的减少有关。然而，关于无保护的重复阳光暴露对皮肤脂质组成的影响，特别是神经酰胺谱的影响，知之甚少。本研究使用离体皮肤和临床模型研究了紫外线（UV）辐射对神经酰胺谱的影响。UV 暴露皮肤的脂质组学分析显示，修复和增强 SC 屏障的神经酰胺亚类（包括 CER1[EOS]、CER3[NP]和 CER6[AP]）的组成发生变化，酰基链长变短。关键酶（aSMase、DES1、CerS5、CerS3）的基因表达分析和免疫组织化学染色表明，脂质变化可归因于神经酰胺生物合成过程中的变化。含有神经酰胺的防晒产品的局部应用有助于维持 SC 中必需的神经酰胺亚类和适当的神经酰胺链长，这表明适当的防晒对于在日常阳光暴露下维持健康的皮肤屏障和神经酰胺质量非常重要。J 皮肤病药物杂志。2022；21(1):77-85. doi:10.36849/JDD.6331.
