Lipid conformational order and the etiology of cataract and dry eye.
Lipid conformational order and the etiology of cataract and dry eye.
复制标题
DOI：
10.1194/jlr.tr120000874
复制
发表时间：
2021
影响因子：
6.5
通讯作者：
Borchman D
中科院分区：
文献类型：
--
作者：
Borchman D
晶状体和泪膜脂质与它们所处的系统一样独特。人体晶状体的主要脂质是二氢鞘肌蛋白，其数量仅在晶状体中发现。晶状体中胆固醇与磷脂的摩尔比高达10:1，比身体其他任何部位都要高。晶状体脂质有助于维持晶状体的清晰度，而年龄导致的晶状体脂质组成的改变很可能导致白内障。晶状体脂质组成反映了对晶状体独特特征的适应：晶状体脂质或蛋白质没有周转；含氧量：任何组织中含氧量最低的；几乎不含胞内细胞器。泪膜脂质层（TFLL）也是独一无二的。TFLL是覆盖在角膜泪液表面的一层薄的（100纳米）脂质层，有助于泪液膜的稳定性。TFLL的主要脂质是蜡酯和胆固醇酯，在晶状体中没有发现。与酯类相关的碳氢化合物链比体内其他任何地方发现的都要长（长达32个碳），而且许多是支链的。3万个不同部分的tfl组成和结构的变化导致泪液的不稳定性。本文的重点是光谱学如何用于阐明脂质组成、构象顺序和功能与白内障和干眼症病因之间的关系。
Lens and tear film lipids are as unique as the systems they reside in. The major lipid of the human lens is dihydrosphingomylein, found in quantity only in the lens. The lens contains a cholesterol to phospholipid molar ratio as high as 10:1, more than anywhere else in the body. Lens lipids contribute to maintaining lens clarity, and alterations in lens lipid composition due to age are likely to contribute to cataract. Lens lipid composition reflects adaptations to the unique characteristics of the lens: no turnover of lens lipids or proteins; the lowest amount of oxygen of any tissue; and contains almost no intracellular organelles. The tear film lipid layer (TFLL) is also unique. The TFLL is a thin (100 nm) layer of lipid on the surface of tears covering the cornea that contributes to tear film stability. The major lipids of the TFLL are wax esters and cholesterol esters that are not found in the lens. The hydrocarbon chains associated with the esters are longer than those found anywhere else in the body (as long as 32 carbons), and many are branched. Changes in the composition and structure of the 30,000 different moieties of TFLL contribute to the instability of tears. The focus of the current review is how spectroscopy has been used to elucidate the relationships between lipid composition, conformational order and function, and the etiology of cataract and dry eye.