Single-Vesicle Landscape of Ti-EVs in Age-related and High Myopic Cataracts
Using the ExoDisc, we isolated Ti-EVs from the lens capsules of 9 patients with age-related cataracts and 7 patients with high myopic cataracts. This analysis identified a total of 260 proteins, and unsupervised clustering of their expression profiles indicated significant pathological heterogeneity between the two types of cataracts (Figure 2A). Among these proteins, 21 were differentially expressed between the groups (Figure 2B; Table S2); specifically, 13 proteins, including ABCG2, ERBB2, and CD86, were significantly enriched in high myopic cataracts, while 8 proteins were more abundant in the Ti-EVs of age-related cataracts (Figure 2C, D). Further analysis using Harmony to adjust for batch effects identified 65 subclusters comprising a total of 102,156 Ti-EVs, which were evenly distributed across both types of cataracts (Figure 2E, F; Table S3). Based on protein markers within each subcluster, we classified the Ti-EVs into seven clusters: Adhesion, AQP1, Immunity, Lysosome, Metabolize, Signal transduction, and SLC12A1&SLC12A3 (Figure 2G). Notably, each subcluster displayed distinct and clearly distinguishable protein profiles (Figure 2H).
Our data indicated that the Immunity cluster was the predominant Ti-EVs type in cataracts. Additionally, despite having two fewer samples, the Lysosome cluster was more prevalent in pathological cataracts (Figure 2I). There were no significant differences in Ti-EV between samples, and each cluster was well represented across samples, suggesting that the observed patterns are consistent and not significantly affected by individual sample variability (Figure 2J). The Ro/e values for the Lysosome, AQP1, Immunity, and SLC12A1&SLC12A3 clusters were higher in high myopic cataract samples, indicating these ones may potential pathogenic factors (Figure 2K). Notably enriched proteins in the Lysosome cluster included CDH17, LAMP1, HLA-DRA, and IL6 (Figure S1A), while AQP1 and CDCP1 were enriched in the AQP1 cluster (Figure S1B), with a high correlation observed between these two groups (Figure S1C). Interestingly, ABCG2, ERBB2, and CD86 were primarily located in the Immunity cluster, suggesting a possible role in the progression of high myopic cataracts.