Tao Ye, Ma Zhao, Liu Bei, Fang Wei, Qin Limin, Huang Yi Fei, Wang Lu, Gao Yanling
Department of Ophthalmology, Key Lab of Ophthalmology and Visual Science, Chinese PLA General Hospital, Beijing 100853, PR China.
Department of Neurosurgery, Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wu Han, 430014, PR China.
Brain Res. 2018 Jan 1;1678:47-55. doi: 10.1016/j.brainres.2017.10.007. Epub 2017 Oct 13.
Retina is a critical component of the central nerve system that is responsible for the conversion of light stimulus into electrical spikes. Retinitis pigmentosa (RP) comprises a heterogeneous group of inherited retinal dystrophies leading to blindness. We examined retinal neuroglobin (Ngb) expression in a pharmacologically induced RP animal model, the N-Methyl-N-nitrosourea (MNU) administered mice. The retinal Ngb expression in MNU administered mice attenuated following a time dependent manner, suggesting Ngb was involved in the photoreceptor degeneration. Conversely, the intravenous delivery of Hemin, a Ngb up-regulator, enhanced the Ngb expressions in the retinas of MNU administered mice. Optokinetic behavioral tests and Electroretinogram (ERG) examination suggested that the Hemin treatment could improve the visual function of MNU administered mice. The retinal morphology of the Hemin treated group was much more intact than the MNU group as evidenced by retinal sections and optical coherence tomography (OCT) examinations. Moreover, immunostaining experiments showed the cone photoreceptors in the MNU administered mice were also rescued by Hemin treatment. Furthermore, mechanism studies suggested the Hemin treatment not only alleviated the oxidative stress, but also rectified the apoptotic changes in the retinas of MNU administered mice. In conclusion, the intraperitoneally delivery of Hemin can enhance the Ngb expressions in the MNU administered retinas, thereby ameliorating the photoreceptor degeneration and associated visual impairments. These findings would shed light on the opportunity to develop Ngb into a therapeutic molecular against RP.
视网膜是中枢神经系统的关键组成部分,负责将光刺激转化为电脉冲。视网膜色素变性(RP)是一组导致失明的遗传性视网膜营养不良的异质性疾病。我们在一种药理学诱导的RP动物模型,即给予N-甲基-N-亚硝基脲(MNU)的小鼠中,检测了视网膜神经球蛋白(Ngb)的表达。给予MNU的小鼠视网膜中Ngb的表达呈时间依赖性减弱,这表明Ngb参与了光感受器的退化。相反,静脉注射Ngb上调剂血红素可增强给予MNU的小鼠视网膜中Ngb的表达。视动行为测试和视网膜电图(ERG)检查表明,血红素治疗可改善给予MNU的小鼠的视觉功能。视网膜切片和光学相干断层扫描(OCT)检查证明,血红素治疗组的视网膜形态比MNU组完整得多。此外,免疫染色实验表明,给予MNU的小鼠中的视锥光感受器也通过血红素治疗得到了挽救。此外,机制研究表明,血红素治疗不仅减轻了氧化应激,还纠正了给予MNU的小鼠视网膜中的凋亡变化。总之,腹腔注射血红素可增强给予MNU的视网膜中Ngb的表达,从而改善光感受器退化和相关的视觉障碍。这些发现将为把Ngb开发成一种治疗RP的分子提供契机。