Disruption and Destabilization of Meibomian Lipid Films Caused by Increasing Amounts of Ceramides and Cholesterol
Disruption and Destabilization of Meibomian Lipid Films Caused by Increasing Amounts of Ceramides and Cholesterol
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DOI：
10.1167/iovs.12-10662
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发表时间：
2013-02-01
影响因子：
4.4
通讯作者：
Butovich, Igor A.
中科院分区：
文献类型：
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作者：
Arciniega, Juan C.;Uchiyama, Eduardo;Butovich, Igor A.
目的。我们使用Langmuir槽（LT）和Brewster角度显微镜（BAM）.methods评估了神经酰胺（CER）和游离胆固醇（FC）对Meibomian脂质膜（MLF）的定量直接作用。 Meibum是从健康的志愿者那里获得的。测试了一系列以不同比率采集的Meibum与CER或FC（混合MLF）的混合物。计算了标准的流变参数，例如MLF的弹性和滞后。 BAM用于研究MLF.Results的形态。纯MLF能够承受几乎没有观察到的磁滞（类似于1.9 j/g meibum）的多个压缩膨胀周期。由纯CER或纯FC制成的电影显然是可折叠的，并且比纯Meibum具有更高的刚度和磁滞性。逐渐增加更高量的CER或FC到Meibum对混合MLF的刚度，稳定性和形态产生了强烈的影响：与纯Meibum相比，它们的滞后率增加了很多。观察到混合MLF的刚性和可折叠性随之增加。 CER和FC以暗示其不稳定和/或破坏的方式改变了混合MLF的表面特性。可能导致这些作用的机制之一是用FC或CER的Meibum脂质的强聚集，导致形成较小的Meibum颗粒，并被较薄的FC或CER所包围。由于CER和FC可以在Meibum和The Tear膜中升高，因为某些病理学过程或可能具有外源性的性质，因此我们的结果可以解释（部分）这些受试者中不稳定的撕裂膜。 （投资Ophthalmol VisSci。2013; 54：1352-1360）doi：10.1167/iovs.12-10662
PURPOSE. We evaluated quantitatively direct effects of ceramide (Cer) and free cholesterol (FC) on meibomian lipid films (MLF) using a Langmuir trough (LT) and a Brewster angle microscope (BAM).METHODS. Meibum was obtained from healthy volunteers. A series of mixtures of meibum with Cer or FC (mixed MLF) taken in different ratios were tested. Standard rheologic parameters, such as elasticity and hysteresis of MLF, were computed. BAM was used to study the morphology of MLF.RESULTS. Pure MLF were capable of withstanding multiple compression-expansion cycles with little hysteresis observed (similar to 1.9 J/g meibum). The films made of either pure Cer or pure FC were clearly collapsible, and had much higher rigidity and hysteresis than pure meibum. Adding progressively higher amounts of Cer or FC to meibum had a strong impact on the rigidity, stability, and morphology of the mixed MLF: their hysteresis increased many fold compared to pure meibum. A concomitant increase in the rigidity and collapsibility of the mixed MLF was observed.CONCLUSIONS. Cer and FC changed the surface properties of mixed MLF in a way that implied their destabilization and/or disruption. One of the mechanisms that might lead to these effects is strong aggregation of meibum lipids with FC or Cer that leads to the formation of smaller particles of meibum surrounded by a thinner layer of FC or Cer. As Cer and FC can be elevated in meibum and the tear film because of certain pathologic processes, or can be of exogenous nature, our results can explain (partially) a less stable tear film in those subjects. (Invest Ophthalmol Vis Sci. 2013;54:1352-1360) DOI:10.1167/iovs.12-10662