Department of Dermatology, School of Medicine, University of California, San Francisco, USA.
Northern California Institute for Research and Education, San Francisco, CA, USA.
Am J Clin Dermatol. 2021 Nov;22(6):853-866. doi: 10.1007/s40257-021-00619-2. Epub 2021 Jul 20.
Ceramides are a class of sphingolipid that is the backbone structure for all sphingolipids, such as glycosphingolipids and phosphosphingolipids. While being a minor constituent of cellular membranes, ceramides are the major lipid component (along with cholesterol, free fatty acid, and other minor components) of the intercellular spaces of stratum corneum that forms the epidermal permeability barrier. These stratum corneum ceramides consist of unique heterogenous molecular species that have only been identified in terrestrial mammals. Alterations of ceramide molecular profiles are characterized in skin diseases associated with compromised permeability barrier functions, such as atopic dermatitis, psoriasis and xerosis. In addition, hereditary abnormalities of some ichthyoses are associated with an epidermal unique ceramide species, omega-O-acylceramide. Ceramides also serve as lipid modulators to regulate cellular functions, including cell cycle arrest, differentiation, and apoptosis, and it has been demonstrated that changes in ceramide metabolism also cause certain diseases. In addition, ceramide metabolites, sphingoid bases, sphingoid base-1-phosphate and ceramide-1-phosphate are also lipid mediators that regulate cellular functions. In this review article, we describe diverse physiological and pathological roles of ceramides and their metabolites in epidermal permeability barrier function, epidermal cell proliferation and differentiation, immunity, and cutaneous diseases. Finally, we summarize the utilization of ceramides as therapy to treat cutaneous disease.
神经酰胺是鞘脂类的一种，是所有鞘脂类（如糖鞘脂和磷酸鞘脂）的骨架结构。虽然神经酰胺是细胞膜的少量组成部分，但它是角质层细胞间空间的主要脂质成分（与胆固醇、游离脂肪酸和其他少量成分一起），形成表皮渗透性屏障。这些角质层神经酰胺由独特的异质分子种类组成，仅在陆地哺乳动物中被发现。在与渗透性屏障功能受损相关的皮肤疾病（如特应性皮炎、银屑病和干燥症）中，神经酰胺分子谱的改变特征明显。此外，一些鱼鳞病的遗传性异常与表皮特有的神经酰胺种类ω-O-酰基神经酰胺有关。神经酰胺还作为脂质调节剂，调节细胞功能，包括细胞周期停滞、分化和凋亡，并且已经证明，神经酰胺代谢的变化也会导致某些疾病。此外，神经酰胺代谢物、鞘氨醇碱基、鞘氨醇-1-磷酸和神经酰胺-1-磷酸也是调节细胞功能的脂质介质。在这篇综述文章中，我们描述了神经酰胺及其代谢物在表皮渗透性屏障功能、表皮细胞增殖和分化、免疫和皮肤疾病中的多种生理和病理作用。最后，我们总结了神经酰胺作为治疗皮肤疾病的用途。
