Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany.
Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Centre for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.
Prog Retin Eye Res. 2024 May;100:101249. doi: 10.1016/j.preteyeres.2024.101249. Epub 2024 Mar 1.
Translocator protein (18 kDa) (Tspo), formerly known as peripheral benzodiazepine receptor is a highly conserved transmembrane protein primarily located in the outer mitochondrial membrane. In the central nervous system (CNS), especially in glia cells, Tspo is upregulated upon inflammation. Consequently, Tspo was used as a tool for diagnostic in vivo imaging of neuroinflammation in the brain and as a potential therapeutic target. Several synthetic Tspo ligands have been explored as immunomodulatory and neuroprotective therapy approaches. Although the function of Tspo and how its ligands exert these beneficial effects is not fully clear, it became a research topic of interest, especially in ocular diseases in the past few years. This review summarizes state-of-the-art knowledge of Tspo expression and its proposed functions in different cells of the retina including microglia, retinal pigment epithelium and Müller cells. Tspo is involved in cytokine signaling, oxidative stress and reactive oxygen species production, calcium signaling, neurosteroid synthesis, energy metabolism, and cholesterol efflux. We also highlight recent developments in preclinical models targeting Tspo and summarize the relevance of Tspo biology for ocular and retinal diseases. We conclude that glial upregulation of Tspo in different ocular pathologies and the use of Tspo ligands as promising therapeutic approaches in preclinical studies underline the importance of Tspo as a potential disease-modifying protein.
转位蛋白(18kDa)(Tspo),以前称为外周苯二氮䓬受体,是一种高度保守的跨膜蛋白,主要位于线粒体外膜。在中枢神经系统(CNS)中,特别是在神经胶质细胞中,Tspo 在炎症时上调。因此,Tspo 被用作脑内神经炎症的体内诊断成像工具和潜在的治疗靶点。已经探索了几种合成的 Tspo 配体作为免疫调节和神经保护治疗方法。尽管 Tspo 的功能及其配体如何发挥这些有益作用尚不完全清楚,但近年来它已成为一个研究热点,尤其是在眼部疾病中。本综述总结了 Tspo 在视网膜不同细胞(包括小胶质细胞、视网膜色素上皮细胞和 Müller 细胞)中的表达及其拟议功能的最新知识。Tspo 参与细胞因子信号转导、氧化应激和活性氧产生、钙信号转导、神经甾体合成、能量代谢和胆固醇外排。我们还强调了针对 Tspo 的临床前模型的最新进展,并总结了 Tspo 生物学在眼部和视网膜疾病中的相关性。我们得出结论,不同眼部病变中神经胶质细胞 Tspo 的上调以及 Tspo 配体作为临床前研究中有前途的治疗方法,强调了 Tspo 作为一种潜在的疾病修饰蛋白的重要性。