Molecular Biologic study for ischemic damage to retinal ganglion cells.

对视网膜神经节细胞受损机制的了解可能会为开发导致视网膜神经节细胞死亡的疾病的新疗法提供必要的信息。为了研究72 kDa热休克蛋白在培养的大鼠视网膜神经节细胞中的表达是否增加了对低氧和兴奋性损伤的耐受性，采用高温(42×Far 1小时)和亚致死性低氧(10%O2 6小时)诱导培养的大鼠视网膜神经节细胞和培养的视网膜Muller细胞合成72 kDa热休克蛋白。用免疫细胞化学和免疫印迹技术检测72 kDa热休克蛋白的诱导。测定培养的视网膜神经节细胞在低氧(0%O2，6小时)和谷氨酸(200微米，6小时或6小时)中的存活率，并与高温或亚致死性低氧应激的对照细胞进行比较。在平行…中评价了热休克蛋白合成的阻断剂--槲皮素的作用。高温和亚致死性缺氧后培养的视网膜神经节细胞和Muller细胞表达热休克蛋白免疫反应。经亚致死量低氧和高温处理的视网膜神经节细胞在缺氧后的平均存活率(*标准差)(以未经处理的对照细胞的百分比表示)(83%*17%)(82%*19%)显著高于未处理的细胞(50%*18%，P&lt；0.001)。经亚致死性低氧和低温处理的细胞经谷氨酸处理后视网膜神经节细胞的平均存活率(82%×19%)显著高于未经处理的CEU(56%×17%，P&lt；0.001)。抑制热休克蛋白的合成可阻断亚致死性低氧和高温对缺氧和谷氨酸暴露后细胞存活的保护作用。高温和亚致死性低氧的神经保护作用提示热休克蛋白对缺血和兴奋性毒性视网膜神经节细胞的死亡具有保护作用。较少

Knowledge of the mechanisms by which retinal ganglion cells are damaged may provide information required to develop novel treatments for diseases that cause retinal ganglion cell death. The authors investigated whether the expression of the 72-kDa heat shock protein in cultured rat retinal ganglion cells increases tolerance to hypoxic and excitotoxic injury.Hyperthermia (42* far 1 hour) and sublethal hypoxia (10% 02 for 6 hours) were used to induce synthesis of the 72-kDa heat shock protein in cultured rat retinal ganglion cells and cultured retinal Muller cells. Induction of the 72.kDa heat shock protein was detected with immunocytochemical and immunoblot techniques. Survival of cultured retinal ganglion cells after exposure to anoxia (0% 02 for 6 hours) and glutamate (200 mum 6or 6 hours) was measured and compared to control cultures stressed previously by hyperthermia or sublethal hypoxia. The effect of quercetin, a blocker of heat shock protein synthesis, was evaluated in parallel … More experiments.Heat shock protein immunoreactivity was expressed in cultured retinal ganglion cells and Muller cell after hyperthermia and sublethal hypoxia. The mean (* standard deviation) retinal ganglion cell survival rates after exposure to anoxia (expressed as a percentage of untreated control cultures) in cells pretreated with sublethal hypoxia (83% * 17%) and hyperthermia (82% * 19%) were significantly greater than for cells that had no pretreatment (50% * 18%, P <0.001). The mean (* standard deviation) retinal ganglion cell survival rate after exposure to glutamate in cells pretreated with sublethal hypoxia (82% * 19%) and hypcrthermia (86% * 17%) were significantly greater than for ceus that had no pretreatment (56% * 17%, P <0.001). Inhibition of heat shock protein synthesis with quercetin abolished the protective effects of sublethal hypoxia and hyperthermia on cell survival after anoxia and glutamate exposure.The neuroprotective effect of hyperthermia and sublethal hypoxia suggests that heat shock proteins confer protection against ischemic and excitotoxic retinal ganglion cell death. Less