With the advancement of molecular biology technology and the development of genetics, the viral vector system has been continuously improved and optimized. The viral vector system has gradually become one of the best carriers in ophthalmic gene therapy. Adenovirus vector has the characteristics of transient expression and plays an important role in reducing corneal immune response. Lentiviral vector has the characteristics of stable and high efficiency and can be expressed slowly in the body for a long time.Adeno-associated virus vector has the characteristics of low immunogenicity, high efficiency and precision and can infect a variety of retinal cells. The combined use of adeno-associated virus vector and CRISPR-Cas9 provides new methods for precise treatment of ophthalmic genetic diseases. The advent of viral vectors has significantly increased the potential of gene therapy and has unparalleled advantages over traditional therapies. We have reason to believe that virus-based gene transduction technology will soon achieve clinical application in the near future, and a large number of difficult ophthalmic problems will be solved by then.
With the development of life sciences and informatics, bioinformatics is developing as an interdisciplinary subject. Its main application is the relationship between genes and proteins and their expression. With the help of genomics, proteomics, transcriptomics, and metabolomics, researchers introduce bioinformatics research methods into fundus disease research. A series of gratifying research results have been achieved including the screening of genetic susceptibility genes, the screening of diagnostic markers, and the exploration of pathogenesis. Genomics has the characteristics of high efficiency and accuracy. It has been used to detect new mutation sites in retinoblastoma and retinal pigment degeneration research, which helps to further improve the pathogenesis of retinal genetic diseases. Transcriptomics, proteomics, and metabolomics have high throughput characteristics. They are used to analyze changes in the expression profiles of RNA, proteins, and metabolites in intraocular fluid or isolated cells in disease states, which help to screen biomarkers and further elucidate the pathogenesis. With the advancement of technology, bioinformatics will provide new ideas for the study of ocular fundus diseases.
Objective To explore the effect of bone morphogenetic protein 4 (BMP4) on the glycolysis level of human retinal microvascular endothelial cells (hRMECs). MethodsA experimental study. hRMECs cultured in vitro were divided into normal group, 4-hydroxynonenal (HNE) group (4-HNE group) and 4-HNE+BMP4 treatment group (BMP4 group). 4-HNE group cell culture medium was added with 10 μmmol/L 4-HNE; BMP4 group cell culture medium was added with recombinant human BMP4 100 ng/ml after 6 h stimulation with 10 μmol/L 4-HNE. The levels of intracellular reactive oxygen species (ROS) were detected by flow cytometry. The effect of 4-HNE on the viability of cells was detected by thiazole blue colorimetry. Cell scratch test and Transwell cell method were used to determine the effect of 4-HNE on cell migration. The relative expression of BMP4 and SMAD9 mRNA and protein in normal group and 4-HNE group were detected by real-time quantitative polymerase chain reaction and Western blot. Seahorse XFe96 cell energy metabolism analyzer was used to determine the level of intracellular glycolysis metabolism in normal group, 4-HNE group and BMP4 group. One-way analysis of variance was used for comparison between groups. ResultsThe ROS levels in hRMECs of normal group, 4-HNE group and BMP4 group were 21±1, 815±5, 810±7, respectively. Compared with the normal group, the levels of ROS in the 4-HNE group and the BMP4 group were significantly increased, and the difference was statistically significant (F=53.40, 50.30; P＜0.001). The cell viability in the normal group and 4-HNE group was 1.05±0.05 and 1.28±0.05, respectively; the migration rates were (0.148±0.005)%, (0.376±0.015)%; the number of cells passing through the pores were 109.0±9.6, 318.0±6.4, respectively. Compared with the normal group, the 4-HNE group had significantly higher cell viability, cell migration rate, and the number of cells passing through the pores, and the differences were statistically significant (F=54.35, 52.84, 84.35; P＜0.05). The relative expression levels of BMP4 and SMAD9 mRNA in the cells of the 4-HEN group were 1.680±0.039 and 1.760±0.011, respectively; compared with the normal group, the difference was statistically significant (F=53.66, 83.54; P＜0.05). The relative expression levels of BMP4 and SMAD9 proteins in the cells of the normal group and 4-HEN group were 0.620±0.045, 0.860±0.190, 0.166±0.049, 0.309±0.038, respectively; compared with the normal group, the differences were statistically significant (F=24.87, 53.84; P＜0.05). The levels of intracellular glycolysis, glycolytic capacity and glycolytic reserve in normal group, 4-HNE group and BMP4 group were 1.21±0.12, 2.84±0.24, 1.78±0.36, 2.59±0.11, 5.34±0.32, 2.78±0.45 and 2.64±0.13, 5.20±0.28, 2.66±0.33. Compared with the normal group, the differences were statistically significant (4-HNE group: F=86.34, 69.75, 58.45; P＜0.001; BMP4 group: F=56.87, 59.35, 58.35; P＜0.05). There was no significant difference in intracellular glycolysis, glycolysis capacity and glycolysis reserve level between 4-HNE group and BMP4 group (F=48.32, 56.33, 55.01; P＞0.05). ConclusionBMP4 induces the proliferation and migration of hRMECs through glycolysis.
Blood-retina barrier destruction, nerve injury, formation of neovascularization and fibroblast proliferation membrane are important pathological changes of DR, which are related to the combined effects of various vitreous cytokines. VEGF is mainly involved in increasing retinal vascular permeability and inducing neovascularization. Pigment epithelium derived factor is vital reducing vascular permeability and neuroprotection; IL plays a key role in mediating inflammatory response. TNF-α is related to inflammation, which is significantly up-regulated by hypoxia. TGF-β is an important cytokine regulating cell proliferation and differentiation. Connective tissue growth factor can promote the growth, migration and adhesion of endothelial cell. In addition, many other molecular mechanisms have not been fully elucidated, and further study on the molecular mechanism of DR is urgent. With the further study of molecular mechanism, the early intervention and targeted treatment of DR will be more effective.
Objective To study the effects of connective tissue growth factor (CTGF) on retinal Müller cells based on transcriptome analysis of RNA-seq technology.MethodsRetinal Müller cells were divided into the control group and the CTGF treatment group which was continuously cultured with 10 ng/ml of CTGF for 24 h. The influence of CTGF on the migration of Müller cells were tested by scratching experiments. The RNA transcriptome analysis was applied to complete transcriptome sequencing, differentially expressed genes and functional enrichment analysis of the two groups of cells. HiSeq sequencing technology was used to sequence the whole transcriptome of the two groups of cells to obtain biological big data, and analyze the differentially expressed miRNAs on this basis. The functions and signal pathways of differential miRNAs were analyzed through gene annotation (GO) functional significance enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway significant enrichment analysis. Based on transcriptome data, genes with differential expression multiples in the top ten between the two groups were screened out, and the expression of bone morphogenetic protein 4 (BMP4) gene was verified by real time fluorescence quantification PCR (qRT-PCR), immunofluorescence and Western blot.ResultsAfter CTGF stimulation of Müller cells, cell viability and mobility which compared with the control group were significantly increased, with statistically significant differences (t=3.453, P＜0.05). The differential gene expression profile of CTGF induced Müller cells was obtained by RNA transcriptome analysis. Comparing the sequencing results of the two groups, it was found that 325 differentially expressed genes included 152 up-regulated genes and 173 down-regulated genes. The results of GO functional significance enrichment analysis showed that the functions of differential miRNA were mainly divided into three categories: biological processes, cellular components, and molecular functions. These differentially expressed genes were involved in signaling between nervous systems, adhesion between cells, and the interaction between cytokines and their receptors. These differentially expressed genes were involved in different metabolic pathways and biological processes such as tissue inflammation and fibrosis. BMP4 gene was seected for verification through immunofluorescence, qRT-PCR and western blot. The results showed that the expression of BMP4 was significantly higher than that in the control group, and the difference was statistically significant (t=39.490, 10.110, 5.470; P=0.004, 0.001, 0.006).ConclusionCTGF promotes cell proliferation and migration by up-regulating the expression of BMP4 in Müller cells, leading to tissue fibrosis and inducing inflammation.
ObjectiveTo investigate the effects of interferon gene stimulating protein (STING) inhibitor (C176) on human retinal microvascular endothelial cells (hRMEC) under oxidative stress. MethodsAn animal experimental study. In vivo experiment: 48 healthy male C57BL/6J mice were randomly divided into wild type mice group (WT group) and diabetes (DM) group, with 24 mice in each group. DM mice were induced by streptozotocin to establish DM model. After successful modeling, DM group was divided into DM+dimethyl sulfoxide (DMSO) group and DM+C176 group, with 12 mice in each group. The mice in the DM+DMSO group were intraperitoneally injected with DMSO at the dose of 50 mg/kg. Mice in DM+C176 group were intraperitoneally injected with STING inhibitor C176 750 nmol at the dose of 50 mg/kg. Four weeks after modeling, immunohistochemical staining, Western blot and real-time fluorescence quantitative polymerase chain reaction were used to detect the expression of STING in the retina of WT and DM mice. The leukocyte adhesion test was used to detect the number of leukocytes adhering to hRMEC in mice with WT, DM+DMSO and DM+C176 groups. In vitro experiment: hRMEC was randomly divided into conventional culture cell group (N group), dimethyl sulfoxide (DMSO) group (with DMSO intervention) and C176 group (with C176 intervention). The cells were induced by 150 μg/ml glycation end products for each group. In vitro leukocyte adhesion test combined with 4', 6-diamino-2-phenylindole staining was used to detect the number of leukocytes adhering to hRMEC. The adherent leukocytes were quantitatively analyzed by flow cytometry; H2DCFDA/reactive oxygen species (ROS) fluorescence probe was used to detect ROS expression in cells; Seahorse XFe96 cell energy metabolism analyzer was used to measure the level of intracellular glycolysis. t-test was used to compare the two groups; single factor analysis of variance was used to compare the three groups. ResultsIn vivo experiment: compared with WT group, the expression level of STING (t=73.248) and the relative expression amount of mRNA (t=67.385) in the retina of DM group mice increased significantly (P＜0.05). Compared with WT group, the number of leukocytes adhering to the retinal vessels of mice in DM+DMSO group was significantly increased, while that in DM+C176 group was significantly decreased (F=84.352, P＜0.01). In vitro: compared with N group and DMSO group, the number of leukocyte adhesion on hRMEC in C176 group decreased significantly (F=35.251, P＜0.01). Compared with N group, the number of leukocytes adhering to hRMEC in DMSO group and C176 group decreased significantly (F=26.374, P＜0.01). The ROS level in hRMEC in C176 group was significantly lower than that in N group and C176 group (F=41.362, P＜0.01). Compared with N group and DMSO group, the glycolysis level of hRMEC in C176 group was significantly reduced, with a statistically significant difference (F=68.741, P＜0.01). ConclusionInhibiting the expression of STING in retinal vascular endothelial cells can improve the progress of DM by inhibiting leukocyte adhesion, ROS production and glycolysis level.
ObjectiveTo analyze the expression of miRNA involved in regulating retinal neovascularizationin in retinal tissue of oxygen-induced retinopathy (OIR) mice.MethodsEighty healthy C57BL/6J mice were randomly divided into control group and OIR group at postnatal day 7(P7). Control group were not received any treatment and then exposed to room air. The OIR group was exposed to (75±2)% oxygen and then under room air at P12. Mice of all groups were euthanized at P17. Retinal neovasculation (RNV) was evaluated by counting the number of pre-retinal neovascular cells and analysing no perfusion area by immunofluorescent staining of the mouse retina.Total RNA was extracted from retinal tissue,and miRNA microarrays was performed to identify differentially expressed miRNA in the two groups. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed differential microRNA.ResultsCompared with the control group,the retinal neovascular tufts and the no perfusion area were both significantly smaller than those in OIR group. The number of pre-retinal neovascular cell nuclei in retinas from control group were obviously lower than those in the retinas from OIR group (t=9.025, P＜0.05). MiRNA microarray analysis showed that 54 miRNA in OIR group showed statistically different expression in control group, 47 miRNA were up-regulated and 7 miRNA were down-regulated. The results of PCR were consistent with the trend of microarray. In GO analysis, 1112 items were significantly different (P＜0.05), and 65 items were significantly different in KEGG analysis of expression profile (P＜0.05).ConclusionsThe miRNA expression in retinal tissue of OIR mice is different from that of normal mice, and these miRNA may be involved in the development of RNV. There are 54 miRNA expression differences in retinal tissue of OIR compared with normal mouse retinal tissue.
ObjectiveTo investigate the protection and the corresponding molecular mechanisms of polypyramidine tract binding protein-associated splicing factor (PSF) overexpression on human retinal microvascular endothelial cells (hRMECs) induced by advanced glycation end-products (AGEs).MethodsThe hRMECs were divided into the normal group, the vector group, PSF group, zinc protoporphyrin (ZnPP) group and PSF+ZnPP group for experiment. Cells in the normal group were cultured in a DMEM medium containing 10% fetal calf serum, penicillin/streptomycin, and placed in a closed constant temperature incubator at 37 °C, 95% air, and 5% CO2. Cells in the vector group were infected with empty lentivirus. The cells in the PSF group were infected with overexpressing PSF lentivirus. Cells in the ZnPP group were treated with ZnPP (10 mol/L) for 2 h. The PSF+ZnPP group cells were infected with overexpressing PSF lentivirus, and then pretreated with ZnPP (10 mol/L) for 2 h. With the last four groups of cells stimulated with AGEs, HE, Hoechst33258 staining and flow cytometry were used to observe the protective effect of high expression of PSF on cell damage and the antagonistic effect of ZnPP on PSF. Western blot was used to detect the protein expression of heme oxygenase-1 (HO-1), phosphorylated (p) extracellular regulatory protein kinase (ERK), and Nrf2 in the cells. U0126, a specific antagonist of ERK pathway, was introduced, and Western blot verified the reversal effect of U0126 on the expression of HO-1 induced by PSF protein.ResultsHE staining and Hoechst33258 staining showed that the number of nuclei of damaged cells of PSF group were significantly increased compared with control group, while decreased compared with PSF+ZnPP group (F=27.5, 38.7; P＜0.05). The results of flow cytometry showed that the ROS produced by cells in the PSF group was significantly increased compared to the normal group, and significantly decreased compared to the PSF+ZnPP group, the difference was statistically significant (F=126.4, P＜0.05). Western blot results showed that HO-1 expression of PSF group was significantly increased compared with control and the vector group (F=70.1, P＜0.05). AGEs inducement of 30, 60, 120 and 240 min could significantly improve pERK expression compared with 15 min (F=474.0, P＜0.05). The expression of HO-1 and Nrf2 proteins in the PSF+/U0126－ group was significantly more than those in the PSF－/U0126－ group, the expression of HO-1 and Nrf2 proteins in the PSF+/U0126+ group was significantly lower than that in the PSF+/U0126－ group, and the differences were statistically significant (F=30.2, 489.4; P＜0.05).ConclusionOver expression of PSF can promote the HO-1 expression by activating ERK pathway and promoting the Nrf2 to the nucleus, thus protect hRMECs against AGEs-induced oxidative damage.
ObjectiveTo screening differentially expressed genes (DEGs) in proliferative diabetic retinopathy (DR) patients to provide new biological therapeutic targets for proliferative DR (PDR) therapy. MethodsA basic research. A total of 3 PDR patients (group PDR) and 3 non-diabetic patients (control group) were enrolled in the study in Tianjin Medical University Eye Hospital in October 2020. In addition, 40 cases of PDR and non-diabetic patients were selected and divided into PDR validation group and control validation group. Peripheral blood validation test was performed in PDR validation group and control validation group; RNA sequencing was performed in PDR group and control group. Transcriptomics (RNAseq) sequencing technology was used to screen DEG in PDR group and control group. The selected DEGs were analyzed by gene ontology (GO) function enrichment analysis, signal pathway enrichment analysis of Kyoto Encyclopedia of Genes and Genomes (KEGG) and protein-protein interaction network (PPI). The gene expression database was used to find the high-throughput data related to PDR, and multi queue comparison analysis was carried out. The target genes of differentially expressed miRNAs were predicted through targetscan platform, so as to clearly screen the correlation between DEG and PDR. Reverse transcription polymerase chain reaction and Western blot were used to verify the expression of DEG mRNA and protein related to PDR. The relative expression of PDR related DEG mRNA and protein between PDR validation group and control validation group were compared by paired t-test. ResultsA total of 1 337 DEGs were screened by RNAseq sequencing in the peripheral blood of patients with PDR, of which 419 genes were up-regulated and 918 down-regulated. Among them, direct inhibitor of apoptosis protein-binding protein with low isoelectric point (DIABLO), zinc finger and BTB domain containing 10 (ZBTB10), polo-like kinases 3 (PLK3), regulatory subunit 1 (PIK3R1) and B cell translocation gene 3 (BTG3) were differentially expressed in PDR patients. The function of GO was enriched from the analysis of molecular function, biological process and cellular composition. The results showed that DIABLO, ZBTB10, PLK3, PIK3R1, BTG3 were involved in the pathological process related to PDR. KEGG enrichment analysis showed that glucose metabolic pathways such as extracellular matrix receptors, cytokine regulatory pathway, p53 signal pathway and galactose metabolism may be involved in the process of differential genes. The analysis of PPI protein interaction network showed that the larger the DEG-associated protein node, the greater the number of associated nodes. Among them, DIABLO, ZBTB10, PLK3, PIK3R1 and BTG3 played significant roles in the formation of the action network. By comparing and analyzing the existing high-throughput data related to diabetic retinopathy in Gene Expression Omnibus database and predicting by Targetscan platform, it was found that some significant differences in miRNA reported in aqueous humor, vitreous fluid and plasma of DR patients can be regulated by the differential genes found in this study. Compared with the control verification group, the relative expressions of DIABLO, ZBTB10, PLK3, PIK3R1 mRNA and protein in peripheral blood of the PDR verification group were up-regulated, and the relative expression of BTG3 mRNA and protein was down-regulated. ConclusionDIABLO, ZBTB10, PLK3, PIK3R1 and BTG3 are DEGs in patients with PDR, and they can participate in the disease process by regulating the biological processes of cell proliferation, fibrosis and oxidative stress.
ObjectiveTo observe the effect of bone morphogenetic protein 4 (BMP4) on the proliferation and migration of human retinal microvascular endothelial cells (hRMEC) under oxidative stress. MethodsThe hRMEC cultured in vitro were divided into control group, 4-hydroxynonenal (HNE) treatment group (4-HNE group), 4-HNE+BMP4 group (BMP4 group). Cell culture medium of 4-HNE treatment group was added with 10 μmmol/L 4-HNE; cell culture of BMP4 group was cultured with 10 μmmol/L 4-HNE, and after stimulation for 6 h, 100 ng/ml recombinant human BMP4 was added. The effects of 4-HNE and BMP4 on hRMEC viability was detected by thiazole blue colorimetric method. The effects of 4-HNE and BMP4 on cell migration was determined by cell scratch test. The relative expression of BMP4 mRNA in the cells of the control group and 4-HNE treatment group and the mRNA expression of the control group, the fibronectin (FN) of BMP4 group, laminin (Laminin), α-smooth muscle contractile protein (α-SMA), and collagen type Ⅰ (Collagen Ⅰ), vascular endothelial growth factor (VEGF), and connective tissue growth factor (CTGF) were detected by real-time quantitative polymerase chain reaction (qRT-PCR). Western blot was used to detect the relative expression of BMP4 protein in the control group and 4-HNE group. The control group and 4-HNE group were compared by t test. ResultsCompared with the control group, cell viability (t=12.73, 16.26, P=0.000 2, <0.000 1), cell migration rate (t=28.17, 37.48, P<0.000 1, <0.000 1) in 4-HNE group and BMP4 group were significantly increased, and the difference was statistically significant; the relative expression of BMP4 mRNA and protein in the 4-HNE group was significantly increased, and the difference was statistically significant (t=16.36, 69.35, P=0.000 1, <0.000 1). The qRT-PCR test results showed that compared with the control group, the relative expression of VEGF, FN, Laminin, α-SMA, Collagen Ⅰ, and CTGF mRNA in the cells of the BMP4 group was significantly increased, and the difference was statistically significant (t=10.61, 17.00, 14.85, 7.78, 12.02, 10.61, P=0.0004, <0.000 1, 0.000 1, 0.001 5, 0.000 1, 0.000 4). ConclusionBMP4 can induce the proliferation and migration of hRMEC; it can also regulate the expression of angiogenesis factors and fibrosis-related factors in hRMEC.