Age-Dependent Changes in Heparan Sulfate in Human Bruch's Membrane: Implications for Age-Related Macular Degeneration
Age-Dependent Changes in Heparan Sulfate in Human Bruch's Membrane: Implications for Age-Related Macular Degeneration
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DOI：
10.1167/iovs.14-14126
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发表时间：
2014-08-01
影响因子：
4.4
通讯作者：
Bishop, Paul N.
中科院分区：
文献类型：
--
作者：
Keenan, Tiarnan D. L.;Pickford, Claire E.;Bishop, Paul N.
目的。硫酸乙酰肝素 (HS) 与年龄相关性黄斑变性 (AMD) 有关，因为它是人布鲁赫膜 (BrM) 中补体因子 H (CFH) 的主要结合伴侣，而 CFH 在抑制细胞外基质上的补体激活中发挥着核心作用。目的是研究人类 BrM 中 HS 数量和成分的潜在老化变化。方法。死后的人类眼组织是从没有已知视网膜疾病的捐赠者那里获得的。从 BrM 和神经感觉视网膜中纯化 HS，消化成二糖后，进行荧光标记并通过反相 HPLC 进行分析。采用免疫组化法检测年轻和老年供体黄斑组织切片中的HS和乙酰肝素酶1，并比较外源应用的CFH重组CCP6-8区域（402Y和402H变体）的结合。结果。二糖分析表明，老年捐赠者与年轻捐赠者（平均 82 岁与 32 岁）相比，BrM 中 HS 的平均含量低 50% (P = 0.006)。此外，旧 BrM 中的 HS 硫酸化有小幅但显着的下降。免疫组织化学显示，与年轻供体相比，老年黄斑 BrM 中的 HS 减少了约 50% (P = 0.02)，而老年黄斑 BrM 中的乙酰肝素酶-1 增加了 24% (P = 0.56)。在年轻的供体组织中，与 402Y 形式相比，AMD 相关的 402H CCP6-8 与 BrM 的结合相对较差。在来自老捐献者的 BrM 中，这种差异显着更大 (P = 0.019)。 结论。人类 BrM 中 HS 的数量随着年龄的增长而大幅减少，导致 CFH 的结合位点减少，尤其影响 CFH 402H 变体结合 BrM 的能力。
PURPOSE. Heparan sulfate (HS) has been implicated in age-related macular degeneration (AMD), since it is the major binding partner for complement factor H (CFH) in human Bruch's membrane (BrM), and CFH has a central role in inhibiting complement activation on extracellular matrices. The aim was to investigate potential aging changes in HS quantity and composition in human BrM.METHODS. Postmortem human ocular tissue was obtained from donors without known retinal disease. The HS was purified from BrM and neurosensory retina, and after digestion to disaccharides, fluorescently labeled and analyzed by reverse-phase HPLC. The HS and heparanase-1 were detected by immunohistochemistry in macular tissue sections from young and old donors, and binding of exogenously applied recombinant CCP6-8 region of CFH (402Y and 402H variants) was compared.RESULTS. Disaccharide analysis demonstrated that the mean quantity of HS in BrM was 50% lower (P = 0.006) in old versus young donors (average 82 vs. 32 years). In addition, there was a small, but significant decrease in HS sulfation in old BrM. Immunohistochemistry revealed approximately 50% (P = 0.02) less HS in macular BrM in old versus young donors, whereas heparanase-1 increased by 24% in old macular BrM (P = 0.56). In young donor tissue the AMD-associated 402H CCP6-8 bound relatively poorly to BrM, compared to the 402Y form. In BrM from old donors, this difference was significantly greater (P = 0.019).CONCLUSIONS. The quantity of HS decreases substantially with age in human BrM, resulting in fewer binding sites for CFH and especially affecting the ability of the 402H variant of CFH to bind BrM.