Murakami Y, Matsumoto H, Roh M, Giani A, Kataoka K, Morizane Y, Kayama M, Thanos A, Nakatake S, Notomi S, Hisatomi T, Ikeda Y, Ishibashi T, Connor K M, Miller J W, Vavvas D G
1] Department of Ophthalmology, Retina Service, Angiogenesis Laboratory, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, USA [2] Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
Department of Ophthalmology, Retina Service, Angiogenesis Laboratory, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, USA.
Cell Death Differ. 2014 Feb;21(2):270-7. doi: 10.1038/cdd.2013.109. Epub 2013 Aug 16.
There is no known treatment for the dry form of an age-related macular degeneration (AMD). Cell death and inflammation are important biological processes thought to have central role in AMD. Here we show that receptor-interacting protein (RIP) kinase mediates necrosis and enhances inflammation in a mouse model of retinal degeneration induced by dsRNA, a component of drusen in AMD. In contrast to photoreceptor-induced apoptosis, subretinal injection of the dsRNA analog poly(I : C) caused necrosis of the retinal pigment epithelium (RPE), as well as macrophage infiltration into the outer retinas. In Rip3(-/-) mice, both necrosis and inflammation were prevented, providing substantial protection against poly(I : C)-induced retinal degeneration. Moreover, after poly(I : C) injection, Rip3(-/-) mice displayed decreased levels of pro-inflammatory cytokines (such as TNF-α and IL-6) in the retina, and attenuated intravitreal release of high-mobility group box-1 (HMGB1), a major damage-associated molecular pattern (DAMP). In vitro, poly(I : C)-induced necrosis were inhibited in Rip3-deficient RPE cells, which in turn suppressed HMGB1 release and dampened TNF-α and IL-6 induction evoked by necrotic supernatants. On the other hand, Rip3 deficiency did not modulate directly TNF-α and IL-6 production after poly(I : C) stimulation in RPE cells or macrophages. Therefore, programmed necrosis is crucial in dsRNA-induced retinal degeneration and may promote inflammation by regulating the release of intracellular DAMPs, suggesting novel therapeutic targets for diseases such as AMD.
目前尚无已知的针对干性年龄相关性黄斑变性(AMD)的治疗方法。细胞死亡和炎症是被认为在AMD中起核心作用的重要生物学过程。在此我们表明,受体相互作用蛋白(RIP)激酶介导坏死并增强由dsRNA诱导的视网膜变性小鼠模型中的炎症,dsRNA是AMD中玻璃膜疣的一种成分。与光感受器诱导的凋亡不同,视网膜下注射dsRNA类似物聚肌苷酸-聚胞苷酸(poly(I:C))会导致视网膜色素上皮(RPE)坏死,以及巨噬细胞浸润到视网膜外层。在Rip3基因敲除(-/-)小鼠中,坏死和炎症均被阻止,为聚肌苷酸-聚胞苷酸(poly(I:C))诱导的视网膜变性提供了实质性保护。此外,在注射聚肌苷酸-聚胞苷酸(poly(I:C))后,Rip3基因敲除(-/-)小鼠视网膜中促炎细胞因子(如肿瘤坏死因子-α(TNF-α)和白细胞介素-6(IL-6))水平降低,玻璃体内高迁移率族蛋白B1(HMGB1)的释放减弱,HMGB1是一种主要的损伤相关分子模式(DAMP)。在体外,聚肌苷酸-聚胞苷酸(poly(I:C))诱导的坏死在Rip3缺陷的RPE细胞中受到抑制,这反过来又抑制了HMGB1的释放,并减弱了坏死上清液引起的TNF-α和IL-6诱导。另一方面,Rip3缺陷并没有直接调节聚肌苷酸-聚胞苷酸(poly(I:C))刺激后RPE细胞或巨噬细胞中TNF-α和IL-6的产生。因此,程序性坏死在dsRNA诱导的视网膜变性中至关重要,并且可能通过调节细胞内DAMPs的释放来促进炎症,这为AMD等疾病提示了新的治疗靶点。