Sun Ye, Liu Chi-Hsiu, SanGiovanni John Paul, Evans Lucy P, Tian Katherine T, Zhang Bing, Stahl Andreas, Pu William T, Kamenecka Theodore M, Solt Laura A, Chen Jing
Department of Ophthalmology, Harvard Medical School, Boston Children's Hospital, Boston, MA 02115;
Section on Nutritional Neuroscience, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD 20892;
Proc Natl Acad Sci U S A. 2015 Aug 18;112(33):10401-6. doi: 10.1073/pnas.1504387112. Epub 2015 Aug 4.
Pathologic ocular angiogenesis is a leading cause of blindness, influenced by both dysregulated lipid metabolism and inflammation. Retinoic-acid-receptor-related orphan receptor alpha (RORα) is a lipid-sensing nuclear receptor with diverse biologic function including regulation of lipid metabolism and inflammation; however, its role in pathologic retinal angiogenesis remains poorly understood. Using a mouse model of oxygen-induced proliferative retinopathy, we showed that RORα expression was significantly increased and genetic deficiency of RORα substantially suppressed pathologic retinal neovascularization. Loss of RORα led to decreased levels of proinflammatory cytokines and increased levels of antiinflammatory cytokines in retinopathy. RORα directly suppressed the gene transcription of suppressors of cytokine signaling 3 (SOCS3), a critical negative regulator of inflammation. Inhibition of SOCS3 abolished the antiinflammatory and vasoprotective effects of RORα deficiency in vitro and in vivo. Moreover, treatment with a RORα inverse agonist SR1001 effectively protected against pathologic neovascularization in both oxygen-induced retinopathy and another angiogenic model of very-low-density lipoprotein receptor (Vldlr)-deficient (Vldlr (-/-) ) mice with spontaneous subretinal neovascularization, whereas a RORα agonist worsened oxygen-induced retinopathy. Our data demonstrate that RORα is a novel regulator of pathologic retinal neovascularization, and RORα inhibition may represent a new way to treat ocular neovascularization.
病理性眼部血管生成是导致失明的主要原因,受脂质代谢失调和炎症的影响。维甲酸受体相关孤儿受体α(RORα)是一种脂质感应核受体,具有多种生物学功能,包括调节脂质代谢和炎症;然而,其在病理性视网膜血管生成中的作用仍知之甚少。利用氧诱导增生性视网膜病变的小鼠模型,我们发现RORα表达显著增加,RORα基因缺陷可显著抑制病理性视网膜新生血管形成。RORα缺失导致视网膜病变中促炎细胞因子水平降低,抗炎细胞因子水平升高。RORα直接抑制细胞因子信号转导抑制因子3(SOCS3)的基因转录,SOCS3是炎症的关键负调节因子。抑制SOCS3可消除RORα缺陷在体外和体内的抗炎和血管保护作用。此外,用RORα反向激动剂SR1001治疗可有效预防氧诱导性视网膜病变和另一种极低密度脂蛋白受体(Vldlr)缺陷(Vldlr(-/-))小鼠自发性视网膜下新生血管形成的血管生成模型中的病理性新生血管形成,而RORα激动剂则会加重氧诱导性视网膜病变。我们的数据表明,RORα是病理性视网膜新生血管形成的新型调节因子,抑制RORα可能代表一种治疗眼部新生血管形成的新方法。