ObjectiveTo observe the expression of S100A8 in plasma exosomes, microvesicles (MV), plasma and vitreous in patients with diabetic retinopathy (DR), and verify it in a diabetic rat model, and to preliminarily explore its role in the occurrence and development of DR.MethodsA case-control study. From September 2018 to December 2019, a total of 73 patients with type 2 diabetes, hospitalized patients undergoing vitrectomy, and healthy physical examinations in the Tianjin Medical University Eye Hospital were included in the study. Among them, plasma were collected from 32 patients and vitreous fluid were collected from 41 patients, which were divided into plasma sample research cohort and vitreous sample research cohort. The subjects were divided into simple diabetes group (DM group), non-proliferative DR group (NPDR group) and proliferative DR group (PDR group) without fundus changes; healthy subjects were regarded as normal control group (NC group). In the study cohort of vitreous samples, the control group was the vitreous humor of patients with epimacular membrane or macular hole. Plasma exosomes and microvesicles (MVs) were separated using ultracentrifugation. Transmission electron microscopy, nanometer particle size analyzer and Western blot (WB) were used to characterize exosomes and MVs. The mass concentration of S100A8 was determined by enzyme-linked immunosorbent assay. Eighteen healthy male Brown Norway rats were divided into normal control group and diabetic group with 9 rats in each group by random number table method. The rats of diabetes group were induced by streptozotocin to establish diabetic model. Five months after modeling, immunohistochemical staining and WB were used to detect the expression of S100A8 in the retina of rats in the normal control group and the diabetes group. t test was used for the comparison of measurement data between the two groups. Single-factor analysis of variance were used for the comparison of multiple groups of measurement data.parison of measurement data between the two groups. Single-factor analysis of variance were used for the comparison of multiple groups of measurement data.ResultsExosomes and MVs with their own characteristics were successfully separated from plasma. The concentrations of plasma exosomes and vitreous S100A8 in the PDR group were higher than those in the NPDR group, DM group, NC group, and the difference was statistically significant (P=0.039, 0.020, 0.002, 0.002, P＜0.000,＜0.000). In the plasma sample cohort study, It was not statistically significant that the overall comparison of the S100A8 mass concentrations of plasma and plasma MV in the four groups of subjects (F=0.283, 0.015; P=0.836, 0.996). Immunohistochemical staining showed that retinal ganglion cells, bipolar cells, cone rod cells and vascular endothelial cells in the diabetic group all expressed S100A8 protein. Compared with the normal control group, the expression level of S100A8 in the retina of the diabetic group increased, and the difference was statistically significant (t=8.028, P=0.001).ConclusionsThe level of S100A8 protein in circulating exosomes increases significantly with the severity of DR in patients with type 2 diabetes. S100A8 may be an influential factor in the inflammatory environment of DR and a potential anti-inflammatory therapeutic target.
ObjectiveTo analyze the protein expression changes in the retina of non-arteritic anterior ischemic optic neuropathy (NAION) in rats.MethodsThe rat NAION (rNAION) model was established by Rose Bengal and laser. Twenty Sprague-Dawley rats were randomly divided into 4 groups, the normal control group, the laser control group, the RB injection control group, and the rNAION model group, with 5 rats in each group. The right eye was used as the experimental eye. The retina was dissected at the third day after modeling. Enzyme digestion method was used for sample preparation and data collection was performed in a non-dependent collection mode. The data were quantitatively analyzed by SWATH quantitative mass spectrometry, searching for differential proteins and performing function and pathway analysis.ResultsCompared with the other three control groups, a total of 184 differential proteins were detected in the rNAION group (expression fold greater than 1.5 times and P＜0.05), including 99 up-regulated proteins and 85 down-regulated proteins. The expressions of glial fibrillary acidic protein, guanine nucleotide binding protein 4, laminin 1, 14-3-3γ protein YWHAG were increased. Whereas the expressions of Leucine-rich glioma-inactivated protein 1, secretory carrier-associated membrane protein 5, and Clathrin coat assembly protein AP180 were decreased. The differential proteins are mainly involved in biological processes such as nerve growth, energy metabolism, vesicle-mediated transport, the regulation of synaptic plasticity, apoptosis and inflammation. Pathway enrichment analysis showed that PI3K-Akt signaling pathway and complement and thrombin reaction pathway was related to the disease.ConclusionThe protein expressions of energy metabolism, nerve growth, synaptic vesicle transport and PI3K-Akt signaling pathway can regulate the neuronal regeneration and apoptosis in NAION.
ObjectiveTo detect the protein expression change in the proliferation of human retinal microvascular endothelial cells (hRMECs) stimulated with 4-Hydroxynonenal (4-HNE).MethodshRMECs were in a logarithmic growth phase, and then were separated into 4-HNE-stimulated group and negative control group. The concentration of 4-HNE included 5, 10, 20 and 50 μmol/L in 4-HNE-stimulated group, while the negative control group was added in the same volume of ethanol (the solvent of 4-HNE). Then the cells were stimulated with 4-HNE for 24 hours following by CCK-8 kits incubating for 4 hours to detect absorbance. It was found that 10 μmol/L 4-HNE had the most obvious effect on the proliferation of hRMECs. Therefore, the cellular proteins from 10 μmol/L 4-HNE-stimulated group and negative control group were acquired and prepared by FASP sample preparation method. Data independent acquisition was used for data acquisition, and the GO analysis and pathway enrichment were performed for analysis of differentially expressed proteins.ResultsCCK-8 kits detection results showed that the A value of the 10 and 20 μmol/L 4-HNE-stimulated groups were significantly higher than negative control group and 5 μmol/L 4-HNE-stimulated group (F=25.42, P＜0.01), while there were no differences between 10 and 20 μmol/L 4-HNE-stimulated groups, and the A value of 50 μmol/L 4-HNE-stimulated groups was lower than negative control. A total of 2710 quantifiable proteins were identified by peoteomics, and 118 proteins were differentially expressed (fold change＞1.5, P＜0.05). Seventy-two proteins were up-regulated after 4-HNE stimulation, whereas 46 proteins were down-regulated. Particularly, the expressions of Heme oxygenase-1, Sulfoxdoxin-1, Heat shock protein A1B, Thioredoxin reductase-1, Glutathione reductase, ATPase and prothrombin were increased when cells were added in 4-HNE, whereas the expressions of apolipoprotein A1 and programmed cell death protein 4 were decreased. These differentially expressed proteins were mainly involved in the biological processes such as oxidative stress, cell detoxification, and ATPase-coupled membrane transport.ConclusionAfter stimulated with 4-HNE, the oxidative stress, cell detoxification, and ATPase-coupled membrane transport protein expression may change in hRMECs in order to regulate oxidative stress and growth situation.