Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, TX, USA; Graduate School of Biomedical Sciences, University of Texas Southwestern Medical Center, Dallas, TX, USA.
Department of Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto, Japan; Department of Ophthalmology, Kyoto City Hospital Organization, Kyoto, Japan.
Exp Eye Res. 2020 Oct;199:108189. doi: 10.1016/j.exer.2020.108189. Epub 2020 Aug 15.
Meibomian glands that are embedded in tarsal plates of human eyelids, and sebaceous glands found in the skin, including that of eyelids, are two related types of holocrine glands that produce lipid-rich secretions called meibum and sebum. Pervasive ocular disorders, such as Meibomian gland dysfunction and dry eye, have been linked to changes in the lipid composition of meibum. However, in most described cases the changes were either small, or random, or insufficiently characterized on the molecular level. Here, we present results of comprehensive lipidomic analyses of meibum, tears and sebum of a patient whose secretions were highly abnormal (abnormal meibum, tears and sebum, or AMTS, patient). The lipidomes were characterized on the level of individual lipid species using ultra-high performance liquid chromatography and high resolution mass spectrometry. The major differences between the AMTS patient and normal age- and gender-matched subjects included, among others, severely diminished pools of normal meibomian lipids such as wax esters and cholesteryl esters in meibum and tears, a 2x increase in total cholesteryl esters to wax esters ratio, their skewed molecular profiles, a ~3x increase in free cholesterol to cholesteryl esters ratio, and, most importantly, a 20x to 30x increase in the triglicerides fraction over the norm. Sebum of the AMTS patient was also highly abnormal lacking major wax esters. Notably, the routine blood lipid panel test of the AMTS patient showed no abnormalities. The data imply that the AMTS patient had a severe, previously unreported, metabolic disorder that affected meibogenesis in Meibomian glands and sebogenesis in sebaceous glands. This is, to the best of our knowledge, a first observation of the condition that we have termed High Triglycerides/Low Waxes (HTLW) syndrome.
人类眼睑的睑板中嵌入了睑板腺，皮肤中的皮脂腺，包括眼睑中的皮脂腺，是两种相关的全分泌腺，它们产生富含脂质的分泌物，称为睑脂和皮脂。广泛的眼部疾病，如睑板腺功能障碍和干眼症，与睑脂脂质组成的变化有关。然而，在大多数描述的情况下，这些变化要么很小，要么是随机的，要么在分子水平上没有充分表征。在这里，我们展示了一位患者的睑脂、泪液和皮脂的综合脂质组学分析结果，其分泌物高度异常（异常睑脂、泪液和皮脂，或 AMTS 患者）。使用超高效液相色谱和高分辨率质谱对脂质组进行了个体脂质种类水平的特征描述。与正常年龄和性别匹配的受试者相比，AMTS 患者的主要差异包括，在睑脂和泪液中，正常睑板腺脂质如蜡酯和胆固醇酯的池严重减少，总胆固醇酯与蜡酯的比例增加了 2 倍，它们的分子分布偏斜，游离胆固醇与胆固醇酯的比例增加了~3 倍，最重要的是，三酰甘油的比例比正常情况下增加了 20 到 30 倍。AMTS 患者的皮脂也高度异常，缺乏主要的蜡酯。值得注意的是，AMTS 患者的常规血脂面板测试显示没有异常。这些数据表明，AMTS 患者患有一种严重的、以前未报道的代谢紊乱，影响了睑板腺的睑脂生成和皮脂腺的皮脂生成。据我们所知，这是首次观察到这种情况，我们称之为高甘油三酯/低蜡（HTLW）综合征。
