Rocco Maria Luisa, Balzamino Bijorn Omar, Esposito Graziana, Petrella Carla, Aloe Luigi, Micera Alessandra
Institute of Cell Biology and Neurobiology, CNR, Rome, Italy.
Research Laboratories in Ophthalmology, IRCCS-G.B. Bietti Foundation, Via Santo Stefano Rotondo, 6 I-00184, Rome, Italy.
Graefes Arch Clin Exp Ophthalmol. 2017 Mar;255(3):567-574. doi: 10.1007/s00417-016-3567-8. Epub 2016 Dec 24.
Our previous study highlighted the potential nerve growth factor (NGF) effect on damaged photoreceptors from a rat model of spontaneous Retinitis Pigmentosa (RP). Herein, we tested the combined NGF/anti-vascular endothelial growth factor (αVEGF) effect on cultured retinal cells isolated from Royal College of Surgeons (RCS) rats receiving an intravitreal VEGF injection (iv-VEGF) to exacerbate retinal inflammation/neovascularization.
RCS (n = 75) rats were equally grouped as untreated (n = 25), iv-saline (single saline intravitreal injection; n = 25) and iv-VEGF (single VEGF intravitreal injection; n = 25). Morphological and biochemical analysis or in vitro stimulations with the biomolecular investigation were carried out on explanted retinas. Isolated retinal cells were treated with NGF and αVEGF, either alone or in combination, for 6 days and cells were harvested for morphological and biomolecular analyses.
Infiltrating inflammatory cells were detected in iv-VEGF exposed RCS retinas, indicative of exacerbated inflammation and neovascularization. In cell cultures, NGF/αVEGF significantly increased retinal cell survival as well as rhodopsin expression and neurite outgrowth in photoreceptors. Particularly, NGF/αVEGF upregulated Bcl-2 mRNA, downregulated Bax mRNA, upregulated trkA mRNA and finally upregulated both NGF mRNA and protein.
These data confirm and extend our previous findings on NGF-photoreceptor crosstalk, highlighting that the NGF/αVEGF combination might be an interesting approach for improving neuroprotection of RCS retinal cells and likewise photoreceptors in the presence of neovascularization. Further studies are required to translate this in vitro approach into clinical practice.
我们之前的研究强调了神经生长因子（NGF）对来自自发性视网膜色素变性（RP）大鼠模型受损光感受器的潜在作用。在此，我们测试了NGF/抗血管内皮生长因子（αVEGF）联合作用于从接受玻璃体内注射VEGF（iv-VEGF）以加剧视网膜炎症/新生血管形成的皇家外科学院（RCS）大鼠分离的培养视网膜细胞的效果。
将75只RCS大鼠平均分为未治疗组（n = 25）、玻璃体内注射生理盐水组（单次玻璃体内注射生理盐水；n = 25）和玻璃体内注射VEGF组（单次玻璃体内注射VEGF；n = 25）。对取出的视网膜进行形态学和生化分析或生物分子研究的体外刺激。将分离的视网膜细胞单独或联合用NGF和αVEGF处理6天，然后收获细胞进行形态学和生物分子分析。
在暴露于iv-VEGF的RCS视网膜中检测到浸润性炎症细胞，表明炎症和新生血管形成加剧。在细胞培养中，NGF/αVEGF显著提高了视网膜细胞存活率以及光感受器中视紫红质的表达和神经突生长。特别是，NGF/αVEGF上调了Bcl-2 mRNA，下调了Bax mRNA，上调了trkA mRNA，最终上调了NGF mRNA和蛋白。
这些数据证实并扩展了我们之前关于NGF-光感受器相互作用的发现，突出了NGF/αVEGF联合可能是改善RCS视网膜细胞神经保护以及在存在新生血管形成时光感受器神经保护的一种有意义的方法。需要进一步研究将这种体外方法转化为临床实践。
