Toxicological Centre, Department of Pharmaceutical Sciences, University of Antwerp, Antwerp, Belgium.
Department of In Vitro Toxicology and Dermato-Cosmetology, Vrije Universiteit Brussel, Brussels, Belgium.
Anal Bioanal Chem. 2023 Sep;415(23):5589-5604. doi: 10.1007/s00216-023-04851-z. Epub 2023 Jul 19.
Lipidomics investigates the composition and function of lipids, typically employing blood or tissue samples as the primary study matrices. Hair has recently emerged as a potential complementary sample type to identify biomarkers in early disease stages and retrospectively document an individual's metabolic status due to its long detection window of up to several months prior to the time of sampling. However, the limited coverage of lipid profiling presented in previous studies has hindered its exploitation. This study aimed to evaluate the lipid coverage of hair using an untargeted liquid chromatography-high-resolution mass spectrometry lipidomics platform. Two distinct three-step exhaustive extraction experiments were performed using a hair metabolomics one-phase extraction technique that has been recently optimized, and the two-phase Folch extraction method which is recognized as the gold standard for lipid extraction in biological matrices. The applied lipidomics workflow improved hair lipid coverage, as only 99 species could be annotated using the one-phase extraction method, while 297 lipid species across six categories were annotated with the Folch method. Several lipids in hair were reported for the first time, including N-acyl amino acids, diradylglycerols, and coenzyme Q10. The study suggests that hair lipids are not solely derived from de novo synthesis in hair, but are also incorporated from sebum and blood, making hair a valuable matrix for clinical, forensic, and dermatological research. The improved understanding of the lipid composition and analytical considerations for retrospective analysis offers valuable insights to contextualize untargeted hair lipidomic analysis and facilitate the use of hair in translational studies.
脂质组学研究脂质的组成和功能，通常采用血液或组织样本作为主要研究基质。头发最近作为一种潜在的补充样本类型出现，可以在疾病早期阶段识别生物标志物，并回溯性地记录个体的代谢状态，因为其检测窗口长达采样前几个月。然而，由于之前的研究中脂质分析的覆盖范围有限，限制了其应用。本研究旨在使用非靶向液相色谱-高分辨率质谱脂质组学平台评估头发的脂质覆盖范围。使用最近优化的毛发代谢组学单相提取技术和被公认为生物基质中脂质提取金标准的两相 Folch 提取方法进行了两次不同的三步彻底提取实验。应用的脂质组学工作流程提高了头发脂质的覆盖范围，因为单相提取方法仅能注释 99 种脂质，而 Folch 方法则能注释跨越六个类别的 297 种脂质。头发中首次报道了几种脂质，包括 N-酰基氨基酸、二酰基甘油和辅酶 Q10。该研究表明，头发中的脂质不仅源自头发中的从头合成，还源自皮脂和血液，这使得头发成为临床、法医和皮肤科研究的有价值的基质。对脂质组成的深入了解以及对回顾性分析的分析考虑为非靶向性头发脂质组学分析提供了有价值的见解，并促进了头发在转化研究中的应用。
