A comparison of glycosaminoglycan distributions, keratan sulphate sulphation patterns and collagen fibril architecture from central to peripheral regions of the bovine cornea.
A comparison of glycosaminoglycan distributions, keratan sulphate sulphation patterns and collagen fibril architecture from central to peripheral regions of the bovine cornea.
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DOI：
10.1016/j.matbio.2014.06.004
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发表时间：
2014-09
期刊：
影响因子：
6.9
通讯作者：
Meek, Keith M.
中科院分区：
文献类型：
--
作者：
Ho, Leona T. Y.;Harris, Anthony M.;Tanioka, Hidetoshi;Yagi, Naoto;Kinoshita, Shigeru;Caterson, Bruce;Quantock, Andrew J.;Young, Robert D.;Meek, Keith M.
本研究调查了从中央到周边角膜区域的胶原纤维结构和硫酸角质素（KS）糖胺聚糖（GAG）表位的硫酸化状态的变化。检查新鲜切除的成年牛角膜组织作为从角膜中心向外的径向位置的函数。测量角膜厚度、组织水合作用、羟脯氨酸含量和硫酸化GAG总量。硫酸角质素的高硫酸化和低硫酸化表位通过免疫组织化学进行研究，并通过ELISA进行定量。用免疫组化方法观察硫酸软骨素（CS）和硫酸皮肤素（DS）在软骨中的分布。电子显微镜和X-射线纤维衍射用于确定胶原纤维结构。牛角膜的外周厚度为1021 ± 5.42 μm，定义为距离角膜中心9-12 mm，而中心厚度为844 ± 8.10 μm。角膜的外周比中心稍有水分，但不显著（H = 4.3 vs. H = 3.7），羟脯氨酸含量更丰富（0.12 vs. 0.06 mg/mg角膜干重）。DMMB测定表明，整个角膜的硫酸化GAG总量无变化。免疫组化显示KS的高硫酸化和低硫酸化表位以及DS在整个角膜中存在，CS仅在利姆布斯之前的周边角膜中存在。通过ELISA进行定量，揭示了虽然高和低硫酸化KS在不同径向位置的整个基质深度保持恒定，但高硫酸化表位从角膜中心到外周保持恒定，而低硫酸化表位显著增加。小角X射线衍射和TEM分析都显示胶原原纤维直径保持相对恒定，直到达到外周，之后原纤维变得更宽间隔（从小角X射线衍射分析），并且随着它们接近巩膜具有更大的直径。深度轮廓的同步加速器微束分析表明，在不同的径向位置从角膜中心向外，原纤维直径是更大的表面比在更深的基质区域。纤维间间距也较高，在中间深度的基质比它是在前，后基质区。牛角膜中的胶原原纤维从角膜中心到12 mm径向位置表现出相当一致的间距和直径，之后观察到显著增加。虽然角膜中蛋白聚糖的整体硫酸化水平的恒定性可能与纤维状结构相关，但后者与低硫酸化KS的分布之间没有相关性。蛋白多糖（KS、DS、CS）和胶原与角膜径向位置相关。糖胺聚糖上的总硫酸盐水平在整个角膜中保持恒定。KS和DS是普遍存在的; CS被发现朝向角膜的边缘向前。高硫酸化KS保持不变，低硫酸化KS增加外周。KS的纤维结构和硫酸化水平之间没有相关性。
This study investigated changes in collagen fibril architecture and the sulphation status of keratan sulphate (KS) glycosaminoglycan (GAG) epitopes from central to peripheral corneal regions. Freshly excised adult bovine corneal tissue was examined as a function of radial position from the centre of the cornea outwards. Corneal thickness, tissue hydration, hydroxyproline content, and the total amount of sulphated GAG were all measured. High and low-sulphated epitopes of keratan sulphate were studied by immunohistochemistry and quantified by ELISA. Chondroitin sulphate (CS) and dermatan sulphate (DS) distributions were observed by immunohistochemistry following specific enzyme digestions. Electron microscopy and X-ray fibre diffraction were used to ascertain collagen fibril architecture. The bovine cornea was 1021 ± 5.42 μm thick at its outer periphery, defined as 9–12 mm from the corneal centre, compared to 844 ± 8.10 μm at the centre. The outer periphery of the cornea was marginally, but not significantly, more hydrated than the centre (H = 4.3 vs. H = 3.7), and was more abundant in hydroxyproline (0.12 vs. 0.06 mg/mg dry weight of cornea). DMMB assays indicated no change in the total amount of sulphated GAG across the cornea. Immunohistochemistry revealed the presence of both high- and low-sulphated epitopes of KS, as well as DS, throughout the cornea, and CS only in the peripheral cornea before the limbus. Quantification by ELISA, disclosed that although both high- and low-sulphated KS remained constant throughout stromal depth at different radial positions, high-sulphated epitopes remained constant from the corneal centre to outer-periphery, whereas low-sulphated epitopes increased significantly. Both small angle X-ray diffraction and TEM analysis revealed that collagen fibril diameter remained relatively constant until the outer periphery was reached, after which fibrils became more widely spaced (from small angle x-ray diffraction analysis) and of larger diameter as they approached the sclera. Depth-profiled synchrotron microbeam analyses showed that, at different radial positions from the corneal centre outwards, fibril diameter was greater superficially than in deeper stromal regions. The interfibrillar spacing was also higher at mid-depth in the stroma than it was in anterior and posterior stromal regions. Collagen fibrils in the bovine cornea exhibited a fairly consistent spacing and diameter from the corneal centre to the 12 mm radial position, after which a significant increase was seen. While the constancy of the overall sulphation levels of proteoglycans in the cornea may correlate with the fibrillar architecture, there was no correlation between the latter and the distribution of low-sulphated KS. Proteoglycans (KS, DS, CS) and collagen were correlated with corneal radial position. Total sulfate levels on glycosaminoglycans remained constant across the cornea. KS and DS were ubiquitous; CS was found towards the edge of the cornea onwards. High-sulfated KS remained constant; low-sulfated KS increased peripherally. There was no correlation between fibrillar architecture and sulfation levels of KS.
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影响因子：
5.7
作者：
Aghamohammadzadeh, H;Newton, RH;Meek, KM
通讯作者：
Meek, KM
影响因子：
4.8
作者：
Funderburgh, JL;Corpuz, LM;Conrad, GW
通讯作者：
Conrad, GW
影响因子：
6.9
作者：
Blain, Emma J.;Gilbert, Sophie J.;Duance, Victor C.
通讯作者：
Duance, Victor C.
DOI：
10.1016/0304-4165(86)90306-5
发表时间：
1986-09-04
期刊：
BIOCHIMICA ET BIOPHYSICA ACTA
影响因子：
--
作者：
FARNDALE, RW;BUTTLE, DJ;BARRETT, AJ
通讯作者：
BARRETT, AJ
影响因子：
7.8
作者：
Chakravarti, S;Magnuson, T;Lass, JH;Jepsen, KJ;LaMantia, C;Carroll, H
通讯作者：
Carroll, H