Feng Lili, Ju Meihua, Lee Kei Ying V, Mackey Ashley, Evangelista Mariasilvia, Iwata Daiju, Adamson Peter, Lashkari Kameran, Foxton Richard, Shima David, Ng Yin Shan
Department of Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts.
University College of London Institute of Ophthalmology, London, United Kingdom; Department of Ocular Biology and Therapeutics, University College of London Institute of Ophthalmology, London, United Kingdom.
Am J Pathol. 2017 Oct;187(10):2208-2221. doi: 10.1016/j.ajpath.2017.06.015. Epub 2017 Jul 21.
Current treatments for choroidal neovascularization, a major cause of blindness for patients with age-related macular degeneration, treat symptoms but not the underlying causes of the disease. Inflammation has been strongly implicated in the pathogenesis of choroidal neovascularization. We examined the inflammatory role of Toll-like receptor 2 (TLR2) in age-related macular degeneration. TLR2 was robustly expressed by the retinal pigment epithelium in mouse and human eyes, both normal and with macular degeneration/choroidal neovascularization. Nuclear localization of NF-κB, a major downstream target of TLR2 signaling, was detected in the retinal pigment epithelium of human eyes, particularly in eyes with advanced stages of age-related macular degeneration. TLR2 antagonism effectively suppressed initiation and growth of spontaneous choroidal neovascularization in a mouse model, and the combination of anti-TLR2 and antivascular endothelial growth factor receptor 2 yielded an additive therapeutic effect on both area and number of spontaneous choroidal neovascularization lesions. Finally, in primary human fetal retinal pigment epithelium cells, ligand binding to TLR2 induced robust expression of proinflammatory cytokines, and end products of lipid oxidation had a synergistic effect on TLR2 activation. Our data illustrate a functional role for TLR2 in the pathogenesis of choroidal neovascularization, likely by promoting inflammation of the retinal pigment epithelium, and validate TLR2 as a novel therapeutic target for reducing choroidal neovascularization.
脉络膜新生血管是年龄相关性黄斑变性患者失明的主要原因,目前针对该疾病的治疗方法只能缓解症状,无法根治病因。炎症在脉络膜新生血管的发病机制中起着重要作用。我们研究了Toll样受体2(TLR2)在年龄相关性黄斑变性中的炎症作用。在正常和患有黄斑变性/脉络膜新生血管的小鼠和人眼中,视网膜色素上皮细胞均大量表达TLR2。在人眼的视网膜色素上皮细胞中检测到TLR2信号的主要下游靶点NF-κB的核定位,尤其是在年龄相关性黄斑变性晚期的眼睛中。在小鼠模型中,TLR2拮抗剂可有效抑制自发性脉络膜新生血管的起始和生长,抗TLR2和抗血管内皮生长因子受体2联合使用对自发性脉络膜新生血管病变的面积和数量产生相加的治疗效果。最后,在原代人胎儿视网膜色素上皮细胞中,配体与TLR2结合可诱导促炎细胞因子的大量表达,脂质氧化终产物对TLR2激活具有协同作用。我们的数据表明TLR2在脉络膜新生血管发病机制中发挥功能性作用,可能是通过促进视网膜色素上皮的炎症反应实现的,并验证了TLR2作为减少脉络膜新生血管的新型治疗靶点的有效性。