Transthyretin proteoforms of intraocular origin in human subretinal fluid.
Transthyretin proteoforms of intraocular origin in human subretinal fluid.
复制标题
DOI：
10.1016/j.exer.2022.109163
复制
发表时间：
2022-09
影响因子：
3.4
通讯作者：
Crosson, Jason N.
中科院分区：
文献类型：
--
作者：
Chen, Jianzhong;Cao, Dongfeng;Fortmann, Seth D.;Curcio, Christine A.;Feist, Richard M.;Crosson, Jason N.
关键词：
了解眼部组织和液体的分子组成可以为解决常见致盲原因提供新的方法。视网膜下液积聚在感光细胞外节和视网膜色素上皮（RPE）之间，是正常在视网膜外细胞和脉络膜之间循环的蛋白质和脂质的潜在丰富来源。在此，完整的后处理修饰的蛋白质（蛋白质型）提取5例孔源性视网膜脱离（RRD）的视网膜下液，通过串联质谱分析，并与发表的数据相比，这些相同的蛋白质合成的其他器官。使用来自非患病的人视网膜/RPE的单核转录组学数据来鉴定视网膜下液中的蛋白质是否具有潜在的眼部来源。用适当的对照对两个具有正常黄斑的人供体眼睛进行甲状腺素运载蛋白（TTR）的免疫探测。在视网膜下液中检测到的三种最丰富的蛋白质是白蛋白、TTR和载脂蛋白A-I。值得注意的是，TTR相对于其他蛋白质比其血清对应物更丰富，提示TTR主要在局部合成。检测到TTR的六种蛋白形式，其中谷胱甘肽化TTR在视网膜下液中的相对量（12-43%）远高于血清（<5%）和脑脊液（0.4-13%）中报道的值。此外，检测到推定的糖基化TTR二聚体32，428 Da作为第四大丰度蛋白。视网膜下液中TTR和推定的TTR二聚体的高丰度得到了可用单核转录组数据分析的支持，其显示了RPE中TTR的强且特异性信号。免疫组织化学进一步显示脉络膜基质中的强弥漫性TTR免疫反应性，与视网膜下腔的外段区中的垂直排列的信号和RPE细胞体中的可忽略的信号形成对比。这些结果表明，TTR在视网膜内合成，谷胱甘肽化是至关重要的，其正常功能。对视网膜下液中TTR和其他蛋白质型的组成、功能和数量的进一步研究可以为年龄相关性黄斑变性、家族性淀粉样变性和其他涉及生理脂质转移和氧化应激失调的视网膜疾病的机制、诊断方法和治疗策略提供信息。
Understanding the molecular composition of ocular tissues and fluids could inform new approaches to prevalent causes of blindness. Subretinal fluid accumulating between the photoreceptor outer segments and retinal pigment epithelium (RPE) is potentially a rich source of proteins and lipids normally cycling among outer retinal cells and choroid. Herein, intact post-translationally modified proteins (proteoforms) were extracted from subretinal fluids of five patients with rhegmatogenous retinal detachment (RRD), analyzed by tandem mass spectrometry, and compared to published data on these same proteins as synthesized by other organs. Single-nuclei transcriptomic data from non-diseased human retina/RPE were used to identify whether proteins in subretinal fluid were of potential ocular origin. Two human donor eyes with normal maculas were immunoprobed for transthyretin (TTR) with appropriate controls. The three most abundant proteins detected in subretinal fluid were albumin, TTR, and apolipoprotein A-I. Remarkably, TTR relative to the other proteins was more abundant than its serum counterpart, suggestive of TTR being synthesized predominantly locally. Six proteoforms of TTR were detected, with the relative amount of glutathionylated TTR being much higher in the subretinal fluid (12–43%) than values reported for serum (<5%) and cerebrospinal fluid (0.4–13%). Moreover, a putative glycosylated TTR dimer of 32,428 Da was detected as the fourth most abundant protein. The high abundance of TTR and putative TTR dimer in subretinal fluid was supported by analysis of available single-nuclei transcriptomic data, which showed strong and specific signal for TTR in RPE. Immunohistochemistry further showed strong diffuse TTR immunoreactivity in choroidal stroma that contrasted with vertically aligned signal in the outer segment zone of the subretinal space and negligible signal in RPE cell bodies. These results suggest that TTR in the retina is synthesized intraocularly, and glutathionylation is crucial for its normal function. Further studies on the composition, function, and quantities of TTR and other proteoforms in subretinal fluid could inform mechanisms, diagnostic methods, and treatment strategies for age-related macular degeneration, familial amyloidosis, and other retinal diseases involving dysregulation of physiologic lipid transfer and oxidative stress.
登录
查看更多内容
影响因子：
5.3
作者：
Teixeira AC;Saraiva MJ
通讯作者：
Saraiva MJ
影响因子：
3.4
作者：
Chen L;Cao D;Messinger JD;Ach T;Ferrara D;Freund KB;Curcio CA
通讯作者：
Curcio CA
影响因子：
4.4
作者：
Cheon, Dong Huey;Nam, Eun Ji;Lee, Ji Eun
通讯作者：
Lee, Ji Eun
影响因子：
2.3
作者：
Chen, Jianzhong;Shiyanov, Pavel;Green, Kari B.
通讯作者：
Green, Kari B.
影响因子：
4.4
作者：
Carter-Dawson, Louvenia;Zhang, Yujin;Redell, John B.
通讯作者：
Redell, John B.