Centre for Ophthalmology and Visual Science and the ARC Centre of Excellence in Vision Science, The University of Western Australia, Perth, Australia.
Invest Ophthalmol Vis Sci. 2010 Jun;51(6):3019-28. doi: 10.1167/iovs.09-4692. Epub 2010 Jan 20.
To examine the time-dependent effects of focal axonal ischemia on the retinal ganglion cell (RGC) cytoskeleton.
Eight pigs were used. Small retinal arteriolar branches were occluded by argon laser to induce focal ischemic insults that were maintained for a period of 6 hours or 1 hour. Treated and untreated retinal segments were dissected from the eye after euthanatization. Each retinal segment followed the longitudinal projection of RGC axons from peripheral retina to the optic disc. Antibodies to phosphorylated neurofilament heavy, phosphorylation-independent neurofilament heavy (NFH), neurofilament light, neurofilament medium, microtubule, and microtubule-associated proteins were used to study the axonal cytoskeleton. Glial fibrillary acidic protein and TUNEL staining were also used to examine astrocyte and apoptotic changes, respectively. Comparisons were made between treated and untreated retinal segments.
Cytoskeleton protein changes occurred within ischemic regions and also within retinal tissue on the disc side and peripheral side of the ischemic regions. NFH and microtubule proteins were the earliest cytoskeleton subunits that underwent change. Changes to all cytoskeleton proteins, apart from NFH, occurred in a time-dependent manner within regions of ischemia. In the time points studied, cytoskeleton changes occurred in the absence of detectable astrocyte changes and RGC apoptosis.
An ischemic insult induces RGC cytoskeleton protein change, implying that the local environment plays an important role in modulating axonal structure and function. Cytoskeleton proteins are likely to be important pathogenic mediators of neuronal dysfunction in diseases such as glaucoma and retinal vascular disease.
研究局灶性轴突缺血对视神经节细胞（RGC）细胞骨架的时间依赖性影响。
本研究使用了 8 头猪。通过氩激光闭塞小视网膜小动脉分支，诱导局灶性缺血损伤，持续 6 小时或 1 小时。安乐死后，从眼球中分离出经处理和未经处理的视网膜段。每个视网膜段都遵循 RGC 轴突从周边视网膜到视盘的纵向投影。使用针对磷酸化神经丝重链、磷酸化非依赖性神经丝重链（NFH）、神经丝轻链、神经丝中链、微管和微管相关蛋白的抗体来研究轴突细胞骨架。还使用胶质纤维酸性蛋白和 TUNEL 染色分别检查星形胶质细胞和凋亡变化。对处理和未处理的视网膜段进行了比较。
细胞骨架蛋白变化发生在缺血区域内，也发生在缺血区域的盘侧和周边侧的视网膜组织内。NFH 和微管蛋白是最早发生变化的细胞骨架亚基。除 NFH 外，所有细胞骨架蛋白的变化都在缺血区域内呈时间依赖性发生。在所研究的时间点，在未检测到星形胶质细胞变化和 RGC 凋亡的情况下，细胞骨架发生了变化。
缺血性损伤诱导 RGC 细胞骨架蛋白发生变化，这意味着局部环境在调节轴突结构和功能方面发挥着重要作用。细胞骨架蛋白可能是青光眼和视网膜血管疾病等疾病中神经元功能障碍的重要致病介质。
