Increase in dephosphorylation of the heavy neurofilament subunit in the monkey chronic glaucoma model
Increase in dephosphorylation of the heavy neurofilament subunit in the monkey chronic glaucoma model
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DOI：
10.1167/iovs.02-0398
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发表时间：
2003-01-01
影响因子：
4.4
通讯作者：
Tsukahara, S
中科院分区：
文献类型：
--
作者：
Kashiwagi, K;Ou, B;Tsukahara, S
目的。在猴慢性眼压升高的实验性青光眼模型中，研究重神经丝亚基（NF-H）的磷酸化，该亚基可能深入参与视网膜神经节细胞（RGC）的轴突运输。随机选择成年猴子的一只眼睛进行激光治疗，整个实验过程中眼压保持在30至40毫米汞柱之间。将带有视神经和视交叉的眼球作为一个组织摘除，并使用两种 NF-H 特异性抗体 NF-200 和 SMI31 进行免疫细胞化学观察。 NF-200 与磷酸化和去磷酸化 NF-H 反应，而 SMI 仅与磷酸化 NF-H 反应。计算 SMI31 阳性面积与 NF-200 阳性面积的比率，以定量评估磷酸化状态。分别评估视网膜、筛板 (1,C)、LC 后和视交叉的样本。在颞部视网膜和鼻部视网膜样本之间，或者在视盘的颞部和鼻部区域之间比较视网膜和视神经头处 NF-H 的磷酸化。通过蛋白质印迹分析证实磷酸化状态。结果。在激光治疗的眼睛中，在颞侧观察到椎间盘杯增大，并且上极和下极优先参与神经元损伤。对照眼中的大多数 NF-H 在所有研究区域均被磷酸化，而青光眼眼中的 NF-H 显着去磷酸化，并且与鼻区域相比，颞区的 NF-H 显着去磷酸化。在视交叉处，从激光治疗的眼睛发出的轴突中的 NF-H 高度去磷酸化，并且 NF-H 去磷酸化的程度与青光眼引起的轴突损伤的程度相对应。 Western blot分析显示NF-Hs磷酸化的变化。结论。 RGC 轴突中的 NF-H 因眼压升高而去磷酸化，这可能与青光眼引起的轴突运输损伤密切相关。
PURPOSE. To investigate the phosphorylation of the heavy neurofilament subunit (NF-H), which could be deeply involved in axonal transport of retinal ganglion cells (RGCs), in an experimental glaucoma model of chronic elevation of intraocular pressure (IOP) in monkeys.METHODS. One eye in adult monkeys was randomly selected for laser treatment, and IOP was maintained between 30 and 40 mm Hg throughout the experiment. The eyeballs with the optic nerve and optic chiasm were enucleated as one tissue and were subject to immunocytochemical observation, using two NF-H-specific antibodies, NF-200 and SMI31. NF-200 reacts with both phosphorylated and dephosphorylated NF-H, whereas SMI reacts only with phosphorylated NF-H. Ratios of SMI31-positive to NF-200-positive areas were calculated for quantitative evaluation of phosphorylation status. Specimens from the retina, lamina cribrosa (1,C), post-LC, and optic chiasm were evaluated separately. Phosphorylation of NF-H at the retina and optic nerve head was compared between specimens from temporal retina and nasal retina, or between temporal and nasal regions of the optic disc. The status of phosphorylation was confirmed by Western blot analysis.RESULTS. An enlargement of the disc cup was observed on the temporal side, and the superior and inferior poles were preferentially involved in the neuronal damage in laser-treated eyes. Most NF-Hs in the control eyes were phosphorylated in all investigated regions, whereas those in the glaucomatous eyes were significantly dephosphorylated, and NF-Hs in the temporal region were significantly dephosphorylated compared with those in the nasal region. At the optic chiasm, NF-Hs in axons traveling from laser-treated eyes were highly dephosphorylated, and the extent of NF-H dephosphorylation corresponded to the degree of glaucoma-induced axonal damage. Western blot analysis showed the change in the phosphorylation of NF-Hs.CONCLUSIONS. NF-Hs in RGC axons are dephosphorylated by elevated IOP, which may be deeply involved in glaucoma-induced damage to axonal transport.