Oku Hidehiro, Morishita Seita, Horie Taeko, Kida Teruyo, Mimura Masashi, Kojima Shota, Ikeda Tsunehiko
Department of Ophthalmology, Osaka Medical College, Osaka, Japan.
Invest Ophthalmol Vis Sci. 2017 Sep 1;58(11):4877-4888. doi: 10.1167/iovs.17-22179.
To determine whether P7C3-A20 can inhibit the phosphorylation of the mammalian target of rapamycin (mTOR), depress neuroinflammation, and protect retinal ganglion cells (RGCs) of rats from optic nerve crush (ONC).
The left optic nerve was crushed, and 5.0 mg/kg/d of P7C3-A20, 1.0 mg/kg/d of rapamycin, or their vehicle was injected intraperitoneally for 3 consecutive days beginning 1 day before the ONC. The protective effects on the RGCs were determined by immunohistochemical staining for Tuj-1. The level of phosphorylated mTOR was determined by immunoblotting. The neuroinflammation in the optic nerve was determined by changes in the expression of CD68, TNF-α, MCP-1, and iNOS.
The density of Tuj-1-stained cells in the control was 2010 ± 81.5/mm2 and 1842 ± 80.4/mm2 on days 7 and 14 after the sham operation. These levels were lower at 995 ± 122/mm2 and 450 ± 52.4/mm2 on days 7 and 14 after the ONC, respectively. Rapamycin and P7C3-A20 preserved the density at significantly higher levels on both days (P < 0.05, Scheffe test). The level of phosphorylated mTOR increased by 1.56-fold above the control level on day 7. Rapamycin and P7C3 significantly lowered the level of phosphorylated mTOR to 0.89-fold and 0.67-fold of the control, respectively. There was an accumulation of CD68+ cells that were immunoreactive to TNF-α at the crush site. The expression of MCP-1 and iNOS was increased chiefly in the astrocytes around the lesion. These inflammatory events were suppressed by both rapamycin and P7C3.
P7C3-A20 can inhibit mTOR phosphorylation in the crushed optic nerve, which may suppress neuroinflammation and preserve the RGCs.
确定P7C3 - A20是否能抑制雷帕霉素哺乳动物靶点（mTOR）的磷酸化，减轻神经炎症，并保护大鼠视网膜神经节细胞（RGCs）免受视神经挤压（ONC）损伤。
挤压左侧视神经，并在视神经挤压前1天开始连续3天腹腔注射5.0 mg/kg/d的P7C3 - A20、1.0 mg/kg/d的雷帕霉素或它们的溶剂。通过Tuj - 1免疫组织化学染色确定对RGCs的保护作用。通过免疫印迹法测定磷酸化mTOR的水平。通过CD68、TNF -α、MCP - 1和诱导型一氧化氮合酶（iNOS）表达的变化确定视神经中的神经炎症。
假手术后第7天和第14天，对照组中Tuj - 1染色细胞的密度分别为2010±81.5/mm²和1842±80.4/mm²。视神经挤压后第7天和第14天，这些水平分别降至995±122/mm²和450±52.4/mm²。雷帕霉素和P7C3 - A20在这两天均使细胞密度显著保持在更高水平（P<0.05，谢费检验）。第7天，磷酸化mTOR的水平比对照水平升高了1.56倍。雷帕霉素和P7C3分别将磷酸化mTOR的水平显著降低至对照水平的0.89倍和0.67倍。在挤压部位有对TNF -α呈免疫反应性的CD68⁺细胞聚集。MCP - 1和iNOS的表达主要在损伤周围的星形胶质细胞中增加。雷帕霉素和P7C3均抑制了这些炎症反应。
P7C3 - A20可抑制挤压视神经中mTOR的磷酸化，这可能抑制神经炎症并保护RGCs。
