Compositional differences between infant and adult human corneal basement membranes
Compositional differences between infant and adult human corneal basement membranes
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DOI：
10.1167/iovs.07-0654
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发表时间：
2007-11-01
影响因子：
4.4
通讯作者：
Ljubimov, Alexander V.
中科院分区：
文献类型：
--
作者：
Kabosova, Andrea;Azar, Dimitri T.;Ljubimov, Alexander V.
目的。成人角膜上皮基底膜（EBM）和Descemet膜（DM）成分呈非均匀分布。本研究的目的是确定这些成分在出生后角膜发育过程中的变化。采用免疫荧光法对30例健康成人角膜和10例12 ~ 3岁儿童角膜进行了抗BM成分抗体的研究。婴儿鲍曼层上角膜中央EBM的IV型胶原组成在3年后由α 1- α 2链转变为α 3- α 4链；在成人中，α 1- α 2链仅保留在脑缘基底膜中。层粘连蛋白α 2和β 2链存在于上皮干细胞所在的成体角膜缘基底细胞中。到3岁时，β 2链出现在边缘BM。在所有角膜中，角膜缘BM均含有层粘连蛋白- 3链。在婴儿糖尿病中，在两面均发现了IV型胶原α 1- α 6链、perlecan、nidogen-1、nidogen-2和netrin-4，但它们只存在于成人糖尿病的内皮表面。在婴儿而非成人糖尿病的基质表面，tenascin-C、fibrin -1、SPARC和laminin-332呈阳性。在成人中，VIII型胶原从婴儿糖尿病的内皮表面转移到基质表面。Matrilin-4在3岁后基本消失。本文首次描述了层粘连蛋白γ - 3链、nidogen-2、netrin-4、matrilin-2、matrilin-4在角膜中的分布。观察到的成人和婴儿角膜脑转移的差异可能与出生后角膜成熟过程中机械强度、角膜细胞粘附和分化的变化有关。
PURPOSE. Adult human corneal epithelial basement membrane ( EBM) and Descemet's membrane ( DM) components exhibit heterogeneous distribution. The purpose of the study was to identify changes of these components during postnatal corneal development.METHODS. Thirty healthy adult corneas and 10 corneas from 12-day- to 3-year-old children were studied by immunofluorescence with antibodies against BM components.RESULTS. Type IV collagen composition of infant corneal central EBM over Bowman's layer changed from alpha 1-alpha 2 to alpha 3-alpha 4 chains after 3 years of life; in the adult, alpha 1-alpha 2 chains were retained only in the limbal BM. Laminin alpha 2 and beta 2 chains were present in the adult limbal BM where epithelial stem cells are located. By 3 years of age, beta 2 chain appeared in the limbal BM. In all corneas, limbal BM contained laminin gamma 3 chain. In the infant DM, type IV collagen alpha 1-alpha 6 chains, perlecan, nidogen-1, nidogen-2, and netrin-4 were found on both faces, but they remained only on the endothelial face of the adult DM. The stromal face of the infant but not the adult DM was positive for tenascin-C, fibrillin-1, SPARC, and laminin-332. Type VIII collagen shifted from the endothelial face of infant DM to its stromal face in the adult. Matrilin-4 largely disappeared after the age of 3 years.CONCLUSIONS. The distribution of laminin gamma 3 chain, nidogen-2, netrin-4, matrilin-2, and matrilin-4 is described in the cornea for the first time. The observed differences between adult and infant corneal BMs may relate to changes in their mechanical strength, corneal cell adhesion and differentiation in the process of postnatal corneal maturation.