Differences in Meibum and Tear Lipid Composition and Conformation.
Differences in Meibum and Tear Lipid Composition and Conformation.
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DOI：
10.1097/ico.0000000000002095
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发表时间：
2020-01
期刊：
影响因子：
2.8
通讯作者：
Ramasubramanian A
中科院分区：
文献类型：
--
作者：
Borchman D;Ramakrishnan V;Henry C;Ramasubramanian A
MEIMBUM的组成、结构和功能关系可能为泪膜稳定性的丧失提供深入的见解。虽然对泪脂的构象进行了严格的研究，但泪脂的构象还没有得到很好的研究。前瞻性地收集造血干细胞移植患者的泪脂(TLHSCT)和泪脂(MHSCT)。回顾分析有(MMGD)和无(MN)眉板腺功能障碍的供者的MEIMBUM的红外光谱，以测量其脂质成分和结构。用红外光谱拉伸区测定了甲苯中CH3和CH2的相对含量。本研究的三个主要发现如下：1)与MN相比，MHSCT和MMGD的CH3基团减少了18%；2)TLHSCT的相变温度、协同性和有序性比MHSCT高约20%；3)与MN和MMGD相比，MHSCT和TLHSCT含有更少的双键。泪脂比糖脂更有序，这可能会产生功能上的后果。人泪膜CH3/CH2峰高比与泪膜稳定性的年龄或性别无关。CH3含量相对于CH2含量和饱和度的大小可能导致较高的脂肪代谢顺序，与较年轻的年龄、眉板腺功能障碍和造血干细胞移植后的干眼症有关。因此，碳氢化合物的顺序可能是不稳定的泪膜层的标志或对其有贡献。
The compositional, structural, and functional relationships of meibum may provide insights into the loss of tear film stability. Although the conformation of meibum lipids has been studied rigorously, that of tear lipids has not. Tear lipids (TLHSCT) and meibum (MHSCT) from patients who had hematopoietic stem cell transplantation were pooled prospectively. The infrared spectra of meibum from donors with (MMGD) and without (Mn) meibomian gland dysfunction were retrospectively analyzed to measure the lipid composition and structure. The infrared CH stretching region was used to measure the relative content of CH3 and CH2 moieties in the meibum. The 3 major findings of the current study are as follows: 1) compared with Mn, MHSCT and MMGD had 18% fewer CH3 moieties; 2) compared with MHSCT, the phase transition temperature, cooperativity, and order were approximately 20% greater for TLHSCT; and 3) compared with Mn and MMGD, MHSCT and TLHSCT contained fewer double bonds. Tear lipids are more ordered than meibum lipids, which could have functional consequences. The human meibum peak height ratio of the CH3/CH2 bands is not a factor related to tear film stability with age or sex. The amount of CH3 moieties relative to CH2 moieties and saturation could contribute to a higher meibum lipid order associated with a younger age, meibomian gland dysfunction, and dry eye from hematopoietic stem cell transplantation. Therefore, the hydrocarbon order may be a marker of or contribute to an unstable tear film layer.