Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States.
Beaumont Research Institute, Beaumont Health, Royal Oak, Michigan, United States.
Invest Ophthalmol Vis Sci. 2020 Nov 2;61(13):14. doi: 10.1167/iovs.61.13.14.
The purpose of this study was to test the hypothesis that anti-oxidant and / or anti-inflammation drugs that suppress rod death in cyclic light-reared Pde6brd10 mice are also effective in dark-reared Pde6brd10 mice.
In untreated dark-reared Pde6brd10 mice at post-natal (P) days 23 to 24, we measured the outer nuclear layer (ONL) thickness (histology) and dark-light thickness difference in external limiting membrane-retinal pigment epithelium (ELM-RPE) (optical coherence tomography [OCT]), retina layer oxidative stress (QUEnch-assiSTed [QUEST] magnetic resonance imaging [MRI]); and microglia/macrophage-driven inflammation (immunohistology). In dark-reared P50 Pde6brd10 mice, ONL thickness was measured (OCT) in groups given normal chow or chow admixed with methylene blue (MB) + Norgestrel (anti-oxidant, anti-inflammatory), or MB or Norgestrel separately.
P24 Pde6brd10 mice showed no significant dark-light ELM-RPE response in superior and inferior retina consistent with high cGMP levels. Norgestrel did not significantly suppress the oxidative stress of Pde6brd10 mice that is only found in superior central outer retina of males at P23. Overt rod degeneration with microglia/macrophage activation was observed but only in the far peripheral superior retina in male and female P23 Pde6brd10 mice. Significant rod protection was measured in female P50 Pde6brd10 mice given 5 mg/kg/day MB + Norgestrel diet; no significant benefit was seen with MB chow or Norgestrel chow alone, nor in similarly treated male mice.
In early rod degeneration in dark-reared Pde6brd10 mice, little evidence is found in central retina for spatial associations among biomarkers of the PDE6B mutation, oxidative stress, and rod death; neuroprotection at P50 was limited to a combination of anti-oxidant/anti-inflammation treatment in a sex-specific manner.
本研究旨在验证以下假设，即在周期性光照培养的 Pde6brd10 小鼠中，抑制视杆细胞死亡的抗氧化和/或抗炎药物也对暗适应培养的 Pde6brd10 小鼠有效。
在未经处理的暗适应培养的 Pde6brd10 小鼠出生后第 23 至 24 天，我们测量了外核层（ONL）厚度（组织学）和外部限制膜-视网膜色素上皮（ELM-RPE）的暗-亮厚度差（光学相干断层扫描[OCT]）、视网膜层氧化应激（QUEnch-assiSTed [QUEST]磁共振成像[MRI]）；以及小胶质细胞/巨噬细胞驱动的炎症（免疫组织化学）。在暗适应培养的 P50 Pde6brd10 小鼠中，在给予正常饲料或混合甲烯蓝（MB）+去氧孕烯（抗氧化、抗炎）、MB 或去氧孕烯的各组中测量 ONL 厚度（OCT）。
P24 Pde6brd10 小鼠的上、下视网膜未见明显的暗-亮 ELM-RPE 反应，与高水平 cGMP 一致。去氧孕烯并不能显著抑制仅在雄性 P23 中央外视网膜中发现的 Pde6brd10 小鼠的氧化应激。在 P23 雄性和雌性 Pde6brd10 小鼠的远外周上象限视网膜中观察到明显的视杆细胞变性伴小胶质细胞/巨噬细胞激活，但未见明显的视杆细胞变性。在给予 5mg/kg/天 MB+去氧孕烯饮食的雌性 P50 Pde6brd10 小鼠中测量到显著的视杆细胞保护作用；单独给予 MB 饲料或去氧孕烯饲料或在同样处理的雄性小鼠中未见明显益处。
在暗适应培养的 Pde6brd10 小鼠的早期视杆细胞变性中，在中央视网膜中，PDE6B 突变、氧化应激和视杆细胞死亡的生物标志物之间的空间关联证据很少；在 P50 时的神经保护作用仅限于抗氧化/抗炎治疗的组合，且具有性别特异性。
