Pauklin Mikk, Kakkassery Vinodh, Steuhl Klaus-P, Meller Daniel
Department of Ophthalmology, University of Duisburg-Essen, Essen, Germany.
Curr Eye Res. 2009 Mar;34(3):221-30. doi: 10.1080/02713680802699408.
Membrane-associated mucins are important components of the ocular tear film. Our objective was to characterize the expression of membrane-associated mucins MUC1, MUC4, and MUC16 in healthy cornea, healthy conjunctiva, fibrovascular tissue (pannus) covering the corneal surface in limbal stem cell deficiency (LSCD), human limbal epithelial cells cultivated on intact amniotic membrane (HLEC-AM), and corneal epithelium after transplantation of cultivated limbal epithelium (TCLE).
Total RNA was isolated from six samples of healthy human cornea, healthy conjunctiva, pannus, limbal epithelial cell cultures, and four corneal samples after TCLE. The expression of MUC1, MUC4, and MUC16 was evaluated by real-time polymerase chain reaction (PCR), Western blotting, and immunofluorescence.
Conjunctiva showed a significantly higher expression of MUC1 and MUC4 than cornea, but the expression of MUC16 was similar in both tissues. The expression of MUC1 in HLEC-AM increased, MUC16 decreased, and MUC4 showed no significant difference when compared to cornea. The expression of all studied mucins in conjunctiva was significantly higher than in HLEC-AM. Pannus revealed a similar expression pattern of membrane-associated mucins to conjunctiva. The expression of all studied mucins in pannus was significantly higher than in cornea or HLEC-AM. A corneal expression pattern of membrane-associated mucins was found in all four samples of cornea after TCLE.
A tissue-specific expression of MUC1 and MUC4 but not MUC16 was found in human cornea and conjunctiva. LSCD led to a conjunctival expression pattern of mucins on the corneal surface. A corneal phenotype could be restored after TCLE, confirming the potential of this method to reconstruct the corneal surface.
膜相关黏蛋白是眼表泪膜的重要组成部分。我们的目的是研究膜相关黏蛋白MUC1、MUC4和MUC16在健康角膜、健康结膜、角膜缘干细胞缺乏（LSCD）时覆盖角膜表面的纤维血管组织（血管翳）、在完整羊膜上培养的人角膜缘上皮细胞（HLEC-AM）以及培养的角膜缘上皮移植后（TCLE）的角膜上皮中的表达情况。
从健康人角膜、健康结膜、血管翳、角膜缘上皮细胞培养物的六个样本以及TCLE后的四个角膜样本中分离总RNA。通过实时聚合酶链反应（PCR）、蛋白质印迹法和免疫荧光法评估MUC1、MUC4和MUC16的表达。
结膜中MUC1和MUC4的表达明显高于角膜，但MUC16在两种组织中的表达相似。与角膜相比，HLEC-AM中MUC1的表达增加，MUC16的表达降低，MUC4无显著差异。结膜中所有研究的黏蛋白的表达均明显高于HLEC-AM。血管翳显示出与结膜相似的膜相关黏蛋白表达模式。血管翳中所有研究的黏蛋白的表达均明显高于角膜或HLEC-AM。在TCLE后的所有四个角膜样本中均发现了膜相关黏蛋白的角膜表达模式。
在人角膜和结膜中发现了MUC开和MUC4的组织特异性表达，但未发现MUC16的组织特异性表达。LSCD导致角膜表面出现结膜样黏蛋白表达模式。TCLE后可恢复角膜表型，证实了该方法重建角膜表面的潜力。
