Macular Research Group. Save Sight Institute, The University of Sydney, Australia.
Glia. 2014 Jul;62(7):1110-24. doi: 10.1002/glia.22666. Epub 2014 Mar 31.
Retinal diseases such as macular telangiectasis type 2 (MacTel), age-related macular degeneration (AMD) and diabetic retinopathy (DR) affect both neurons and blood vessels. Treatments addressing both at the same time might have advantages over more specific approaches, such as vascular endothelial growth factor (VEGF) inhibitors, which are used to treat vascular leak but are suspected to have a neurotoxic effect. Here, we studied the effects of an intravitreal injection of triamcinolone acetonide (TA) in a transgenic model in which patchy Müller cell ablation leads to photoreceptor degeneration, vascular leak, and intraretinal neovascularization. TA was injected 4 days before Müller cell ablation. Changes in photoreceptors, microglia and Müller cells, retinal vasculature, differential expression of p75 neurotrophin receptor (p75(NTR) ), tumor necrosis factor-α (TNFα), the precursor and mature forms of neurotrophin 3 (pro-NT3 and mature NT3) and activation of the p53 and p38 stress-activated protein kinase (p38/SAPK) signaling pathways were examined. We found that TA prevented photoreceptor degeneration and inhibited activation of microglial and Müller cells. TA attenuated Müller cell loss and inhibited overexpression of p75(NTR) , TNFα, pro-NT, and the activation of p53 and p38/SAPK signaling pathways. TA not only prevented the development of retinal vascular lesions but also inhibited fluorescein leakage from established vascular lesions. TA inhibited overexpression of VEGF in transgenic mice but without affecting its basal level expression in the normal retina. Our data suggest that glucocorticoid treatment may be beneficial for treatment of retinal diseases such as MacTel, AMD, and DR that affect both neurons and the vasculature.
视网膜疾病,如 2 型黄斑毛细血管扩张症(MacTel)、年龄相关性黄斑变性(AMD)和糖尿病性视网膜病变(DR),既影响神经元又影响血管。同时针对两者的治疗可能优于更具针对性的方法,如血管内皮生长因子(VEGF)抑制剂,该抑制剂用于治疗血管渗漏,但被怀疑具有神经毒性作用。在这里,我们研究了曲安奈德(TA)玻璃体内注射在一个转基因模型中的作用,该模型中斑片状 Müller 细胞消融导致光感受器变性、血管渗漏和视网膜内新生血管形成。TA 在 Müller 细胞消融前 4 天注射。我们检查了光感受器、小胶质细胞和 Müller 细胞、视网膜血管、p75 神经营养因子受体(p75(NTR))、肿瘤坏死因子-α(TNFα)、神经营养因子 3 的前体和成熟形式(pro-NT3 和成熟 NT3)的差异表达以及 p53 和 p38 应激激活蛋白激酶(p38/SAPK)信号通路的激活情况。我们发现 TA 可预防光感受器变性并抑制小胶质细胞和 Müller 细胞的激活。TA 减轻 Müller 细胞丢失并抑制 p75(NTR)、TNFα、pro-NT 和 p53 和 p38/SAPK 信号通路的过度表达。TA 不仅预防了视网膜血管病变的发展,还抑制了从已建立的血管病变中漏出的荧光素。TA 在转基因小鼠中抑制了 VEGF 的过度表达,但不影响其在正常视网膜中的基础表达。我们的数据表明,糖皮质激素治疗可能有益于治疗影响神经元和血管的视网膜疾病,如 MacTel、AMD 和 DR。