Farwanah Hany, Wohlrab Johannes, Neubert Reinhard H H, Raith Klaus
Institute of Pharmaceutics and Biopharmaceutics, Martin Luther University, W.-Langenbeck-Str. 4, 06120 Halle (S.), Germany.
Anal Bioanal Chem. 2005 Oct;383(4):632-7. doi: 10.1007/s00216-005-0044-3. Epub 2005 Oct 19.
The ceramides of the stratum corneum are critical to maintaining the epidermal barrier function of the skin. A number of skin diseases and disorders are known to be related to impairments of the ceramide pattern. Therefore, obtaining mass spectrometric profiles of the nine ceramide classes known to exist aids our understanding of the underlying molecular mechanisms, which should eventually lead to new diagnostic opportunities: for example, the mass spectrometric profiles of patients suffering from serious skin diseases such as atopic dermatitis and psoriasis can be compared to those of healthy controls. Previous work on mass spectrometric analysis of ceramides relied mostly on GC/MS after hydrolysis and derivatization. The introduction of ESI-MS and LC/ESI-MS has provided new options for directly analyzing intact ceramides. However, some of the ceramide classes are not accessible to ESI-MS. However, as shown in this work, these limitations of GC/MS and ESI-MS can be overcome using a new approach based on normal phase LC interfaced with APCI-MS. Separation and online detection of the stratum corneum ceramide classes became possible in one run. Ceramide species with C26 and/or C28 fatty acid chains were the most abundant ones in Cer [NP], Cer [NH], Cer [AP], and Cer [AH]. The main component of Cer [AS] was C16. The omega-esterified ceramide classes Cer [EOS], Cer [EOP] and Cer [EOH] contained mostly species with fatty acids >C30. This was also the case for Cer [NS], suggesting an analogy to the omega-esterified ceramides. In addition, evidence for a new ceramide class Cer [NdS] was found.
角质层中的神经酰胺对于维持皮肤的表皮屏障功能至关重要。已知许多皮肤疾病和紊乱都与神经酰胺模式的损伤有关。因此，获取已知存在的九种神经酰胺类别的质谱图谱有助于我们理解潜在的分子机制，这最终应该会带来新的诊断机会：例如，可以将患有特应性皮炎和牛皮癣等严重皮肤疾病的患者的质谱图谱与健康对照者的图谱进行比较。先前关于神经酰胺质谱分析的工作主要依赖于水解和衍生化后的气相色谱/质谱联用。电喷雾电离质谱（ESI-MS）和液相色谱/电喷雾电离质谱（LC/ESI-MS）的引入为直接分析完整的神经酰胺提供了新的选择。然而，某些神经酰胺类别无法通过ESI-MS进行分析。然而，如本研究所示，使用基于正相液相色谱与大气压化学电离质谱联用的新方法可以克服气相色谱/质谱联用和ESI-MS的这些局限性。一次运行即可实现角质层神经酰胺类别的分离和在线检测。在神经酰胺[NP]、神经酰胺[NH]、神经酰胺[AP]和神经酰胺[AH]中，具有C26和/或C28脂肪酸链的神经酰胺种类最为丰富。神经酰胺[AS]的主要成分是C16。ω-酯化神经酰胺类别神经酰胺[EOS]、神经酰胺[EOP]和神经酰胺[EOH]主要包含脂肪酸>C30的种类。神经酰胺[NS]也是如此，这表明它与ω-酯化神经酰胺类似。此外，还发现了一种新的神经酰胺类别神经酰胺[NdS]的证据。
