McCartney M D, Wood T O, McLaughlin B J
Curr Eye Res. 1987 Apr;6(4):589-97. doi: 10.3109/02713688709025218.
Previous freeze-fracture results from our laboratory have shown a reduction in a population of intramembrane particles in the lateral endothelial membranes from dysfunctional human corneas. The size range of these intramembrane particles corresponds to that which has previously been reported for the glycoprotein enzyme Na, K-ATPase in enzyme enriched freeze-fractured membranes. In order to investigate glycoconjugate changes potentially related to the particle reduction, wheat germ agglutinin (WGA), which has been shown to bind to the sugar residues in the ATPase subunit, was used to label three types of corneas with dysfunctional endothelial cells (Fuchs' endothelial dystrophy, aphakic and pseudophakic bullous keratopathy) and two types of corneas (eye bank and keratoconus) with functional endothelium using the technique of thin section freeze-fracture label. Apical WGA labelling on all types of dysfunctional cells was shown to be drastically reduced in comparison to both types of functional corneal endothelial cells. Lateral membranes of dysfunctional cells, exposed by freeze-fracturing, also showed a great reduction in WGA labelling as compared to the fractured lateral membranes of functional cells. The differences observed in lectin labelling of lateral membranes may be related in part to the decreased intramembrane particle density observed in dysfunctional human corneal endothelial cells.
我们实验室之前的冷冻断裂研究结果表明，功能失调的人角膜外侧内皮细胞膜中的膜内颗粒数量减少。这些膜内颗粒的大小范围与之前在富含酶的冷冻断裂膜中报道的糖蛋白酶钠钾 - ATP酶的大小范围一致。为了研究可能与颗粒减少相关的糖缀合物变化，已证明能与ATP酶亚基中的糖残基结合的麦胚凝集素（WGA），被用于使用薄切片冷冻断裂标记技术标记三种具有功能失调内皮细胞的角膜（富克斯内皮营养不良、无晶状体和假晶状体大疱性角膜病变）以及两种具有功能性内皮的角膜（眼库角膜和圆锥角膜）。与两种功能性角膜内皮细胞相比，所有类型功能失调细胞上的顶端WGA标记都显著减少。通过冷冻断裂暴露的功能失调细胞的外侧膜，与功能性细胞的断裂外侧膜相比，WGA标记也大幅减少。在外侧膜凝集素标记中观察到的差异可能部分与在功能失调的人角膜内皮细胞中观察到的膜内颗粒密度降低有关。
