ObjectiveTo explore the effect of cathepsin L (CTSL) inhibitor on apoptosis of retinal pigment epithelial (RPE) cells and mitochondrial oxidative stress. MethodsRPE cells were cultured in vitro and divided into control group, hydrogen peroxide (H2O2) group, and H2O2+CTSL inhibitor group. The cells of H2O2 group and H2O2+CTSL inhibitor group were incubated in the medium containing 400 μmol/L H2O2 for 24 hours and 10 μmol/L CTSL inhibitor was added in H2O2+CTSL inhibitor group at the same time. The cells of normal group were routinely cultured cells. The follow-up experiment was carried out 24 hours after modeling. The rate of apoptosis was detected by flow cytometry. The expression of CTSL was detected by immunofluorescence staining, Western blot and real time-polymerase chain reaction. The level of mitochondrial super oxide was detected by MitoSOX fluorescent probe, and the mitochondrial structure was observed after MitoTracker staining, the average area, form factors, and branch of mitochondria were quantitatively analyzed. The two groups were compared using two-tailed Student t test, while numerous groups were compared using one-way ANOVA. ResultsCompared with control group, the rate of apoptosis in H2O2 group was significantly higher (t=3.307, P=0.029 7), the expression level of CTSL was significantly increased (t=19.950, 6.916, 14.220; P＜0.05). Compared with H2O2 group, the expression level of CTSL, the rate of apoptosis and the mitochondrial ROS level in H2O2+CTSL inhibitor group were significantly lower (t=11.940, 4.718, 16.680; P＜0.05). The mitochondria of H2O2+CTSL inhibitor group were elongated, oval-shaped or rod-shaped, while the mitochondria of H2O2 group lost their continuous contour shape and complete structure. The differences of the average area, form factors, and brach of mitochondria among 4 groups were statistically significant (F=251.700, 34.010, 60.500; P＜0.000 1). ConclusionsH2O2 can significantly induce apoptosis in RPE cells and increase CTSL expression. CTSL inhibitor can inhibit the H2O2-induced apoptosis of RPE cells, lower the mitochondrial super oxide level, and successfully repair the mitochondrial structure.
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.
ObjectiveTo observe the MiSeq sequencing analysis results of fulvic acid (FA) intervention in hypoxia-induced human retinal microvascular endothelial cell (hRMEC) gene expression profile.MethodshRMEC were cultured in vitro and divided into the hypoxia group (hypoxia treatment) and the FA intervention group (FA intervention after hypoxia). The MTT colorimetric method was used to detect the influence of different concentrations and different modes of FA on hRMEC activity. The optimal concentration of FA was chosen. RT-PCR was used to investigated the effect of FA on hypoxia-induced intercellular adhesion molecule-1 (ICAM-1), IL-1β, IL-4, IL-6, IL-6, IL-8, IL-10, MMP-2, TNF-α, TNF-β, other inflammatory factors in hRMEC, and inflammation-related factors mRNA expression. Cells in the hypoxia group and FA intervention group in the logarithmic growth phase were collected. MiSeq sequencing technology was applyed to complete the whole transcriptome sequencing of the two groups of cells, biological data were obtained, and the differentially expressed miRNA were analyzed on this basis. Gene annotation (GO) functionally significant enrichment analysis and Kyoto Encyclopedia of Genes and Genome (KEGG) pathway significant enrichment analysis were used to analyze the functions and signal pathways of differential miRNAs. The expression of inflammatory factors and inflammation-related factors were compared between groups. The expression level of the corresponding miRNA in the cell was regulated by miRNA mimic, and its effect on cell function was observed, so as to judge the effect of the miRNA.ResultsDifferent concentrations and different modes of action of FA had no effect on the cell viability of hRMEC. The mRNA expression of ICAM-1, IL-1β, IL-6 and TNF-β in the hypoxia group hRMEC were significantly up-regulated compared with the normal group, and the difference was statistically significant (t=3.426, 6.011, 5.282, 6.500; P=0.027, 0.004, 0.006, 0.003); the mRNA expression of ICAM-1, IL-6, TNF-α and TNF-β in the FA intervention group hRMEC was significantly lower than that of the hypoxia group, and the difference was statistically significant (t=9.961, 3.676, 3.613, 3.387; P=0.001, 0.021, 0.023, 0.028). There were 14 differentially expressed miRNAs between the hypoxia group and the FA intervention group, of which 9 were up-regulated genes and 5 were down-regulated genes. The predicted target genes of 4 differential miRNAs (hsa-miR-1285-3p, hsa-miR-30d-3p, hsa-miR-3170, hsa-miR-7976) were all ICAM-1. The results of significant enrichment analysis of GO function showed that the functions of differential genes were mainly enriched in the process of cell development, cell differentiation and single organism development. Significant enrichment analysis of the KEGG pathway showed that the differential miRNA expression was highly enriched in the proteoglycan pathway and the cytokine-cytokine receptor interaction pathway in cancer, and the arachidonic acid metabolism pathway and the amphetamine pathway were the more obvious differential expressions.ConclusionFA may affect the expression level of downstream ICAM-1 mRNA by regulating the expression of multiple miRNAs, thereby affecting the inflammatory state of cells after hypoxia-stimulated hRMEC.
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.
Objective To observe the effect of bone forming protein 4 (BMP4) on the proliferation and migration of human retinal pigment epithelium (RPE) cells under oxidative stress, and to preliminarily explore its effect on epithelial-mesenchymal transition (EMT) of RPE cells. MethodsHuman RPE cells cultured in vitro were divided into normal group, pure 4-hydroxynonenal (HNE) group (4-HNE group), 4-HNE+NC group and 4-HNE+ small interfering BMP (siBMP4) group. The effect of 4-HNE on the proliferation of RPE cells was detected by thiazole blue colorimetry. The effects of 4-HNE and BMP4 on cell migration were determined by cell scratch test. The expression of BMP4 was detected by immunofluorescence staining, Western blot and real-time quantitative polymerase chain reaction. The transfection efficiency of siBMP4 was observed by fluorescence microscopy. Mitochondrial reactive oxygen species (MitoSOX) were detected by flow cytometry. The expression of EMT markers E-cadherin and Fibronection were detected by immunofluorescence assay. t-test was used for comparison between the two groups, and one-way analysis of variance was used for comparison between the three groups. ResultsCompared with normal group, cell proliferation and migration ability of 4-HNE group were significantly enhanced, with statistical significance (t=21.619, 24.469; P＜0.05). The expression of BMP4 in cells was significantly increased, and the difference was statistically significant (t=19.441, P＜0.05). The relative expression levels of BMP4 mRNA and protein were also significantly increased, with statistical significance (t=26.163, 37.163; P＜0.05). After transfection with siBMP4 for 24 h, the transfection efficiency of BMP4 in RPE cells was＞90%. Compared with 4-HNE group and 4-HNE+NC group, the relative expression levels of BMP4 protein (F=27.241), mRNA (F=36.943), cell mobility (F=46.723) and MitoSOX expression levels (F=39.721) in normal group and 4-HNE+siBMP4 group were significantly decreased. The differences were statistically significant (P＜0.05). The epithelial marker E-cadherin increased significantly, while the mesenchymal marker Fibronection decreased significantly, with statistical significance (F= 51.722, 45.153; P＜0.05). ConclusionsBMP4 inhibits RPE proliferation and migration under oxidative stress. BMP4 is involved in inducing EMT in RPE cells.
ObjectiveTo observe RNA-Seq analysis of gene expression profiling in human retinal vascular endothelial cells after anti-vascular endothecial growth factor (VEGF) treatment.MethodsCultured the retinal vascular endothelial cells in vitro and logarithmic growth phase cells were used for experiments. The cells were divided into VEGF group and VEGF combined with anti-VEGF drugs group. The VEGF group cells were treated with 50 ng/ml VEGF for 72 h to simulate the high VEGF survival conditions of vascular endothelial cells in diabetic retinopathy. VEGF combined with anti-VEGF drug group cells was treated with 50 ng/ml VEGF and 2.5 μg/ml anti-VEGF drugs for 72 h to imitate the microenvironment of cells following the anti-VEGF drugs treatment, and whole transcriptome sequencing approach was applied to the above two groups of cells through RNA-Seq. Now with biological big data obtained as a basis, to analyze the differentially expressed genes (DEGs). And through enrichment analysis to explain the differential functions of DEGs and their signal pathways.ResultsThe gene expression profiles of the two groups of cells were obtained. Through analysis, 328 DEGs were found, including 194 upregulated and 133 downregulated ones. The functions of DEGs were influenced by regulations over molecular biological process, cellular energy metabolism and protein synthesis, etc. Among these genes, SI,PRX and HPGD were related to protein synthesis, BIRCT to cellular apoptosis, and ABLIM1 and CRB2 to retinal development, and ABCG1, ABCA9 and ABCA12 were associated with the cholesterol of macrophage and the transfer of phospholipid. GO enrichment analysis showed that DEGs mainly act in three ways: regulating biological behavior, organizing cellular component and performing molecular function. Pathway enrichment analysis showed that gene expressions of the two cell groups were differentiated in ECM receptor pathway, and Notch, mitogen-activated protein kinase, transforming growth factor (TGF)-β and Wnt signal pathways. Among them, the gene expression in TGF-β signal pathway attracts most attention, where the DEGs, such as CAMK2B, COL3A1, CYGB, PTGER2 and HS6ST2, among others, were closely related to fibrosis process.ConclusionThe anti-VEGF drugs may enhance the expression of CAMK2B, COL3A1, CYGB, PTGER2 and others genes related to TGF-β signal pathway and aggravate retinal fibrosis disease.
ObjectiveTo construct the connective tissue growth factor (CTGF) recombinant interference vector (shRNA) and observe its inhibitory effect on the expression of endogenous CTGF in retinal vascular endothelial cells. Methods The human CTGF shRNA was constructed and the high-titer CTGF shRNA lentivirus particles was acquired via three-plasmid lentivirus packaging system to infect retinal vascular endothelial cells. The optimal multiplicity and onset time of lentivirus infection were identified by tracing down the red florescent protein in interference vector. The cells were classified into three groups: blank control group, infection control group and CTGF knockdown group. The differences in cells migrating ability was observed through Transwell allay. The mRNA and protein expression of CTGF, fibronectin, α-smooth muscle actin (α-SMA) and collagen Ⅰ (Col Ⅰ) were quantified through real-time PCR testing and Western blot system. Data between the three groups were examined via one-way analysis of variance. ResultsThe result showed that an optimal multiplicity of 20 and onset time of 72 hours were the requirements to optimize lentivirus infection. Transwell allay result showed a contrast in the number of migrated cells in the CTGF knockdown group and that in the blank control group and infection control group (F=20.64, P=0.002). Real-time PCR testing showed a contrast in related gene expression (CTGF, fibronectin, α-SMA and Col Ⅰ) in the CTGF knocked-down group and that in the blank control group and infection control group (F=128.83, 124.44, 144.76, 1 374.44; P=0.000, 0.000, 0.000, 0.000). Western blot system showed the statistical significance of the contrasted number of related protein expression (CTGF, fibronectin, α-SMA and Col Ⅰ) in the knockdown group and that in the blank control group (F=22.55, 41.60, 25.73, 161.68; P=0.002, 0.000, 0.001, 0.000). ConclusionThe success in producing CTGF shRNA lentivirus particle suggests that CTGF shRNA lentivirus can effectively knock down CTGF expression.
ObjectiveTo investigate the protective effect of butylphenyphthalein (NBP) on RPE apoptosis induced by H2O2.MethodsThe human RPE cell line (human ARPE-19 cell line) were used as the experimental cells and were divided as control group, model group, NBP group. Complete medium was used in control group. The model group was stimulated with 200 μmol/L H2O2 for 2 h, and the cells were cultured in complete medium. The NBP group was cultured with 200 μmol/L H2O2 and 1 μmol/L NBP for 2 h. After changing the medium, complete medium was combined with 1 μmol/L NBP to continue the culture of the cells. Cell viability were detected by MTT assay while the morphology of RPE were observed by HE staining. Moreover, Hoechst 33258 was used to detect RPE cell apoptosis. Mitochondrial membrane potential (JC-1) staining were performed to monitor changes in cell membrane potential and the characteristic change of apoptosis in RPE cells. Furthermore, 2′,7′-Dichlorofluorescin diacetate (DCFH-DA) staining were used to analyze the effect of NBP treatment on the expression of ROS. The effect of NBP on the expression of Heme oxygenase-1(HO-1) was analyzed by cellular immunofluorescence and western blotting.ResultsThe results of MTT assay showed that the cells were cultured for 24 and 48 hours, cell viability of control group (t=17.710, 13.760; P＜0.000 1, ＜0.000 1) and treatment group (t=4.857, 9.225; P=0.000 7, ＜0.000 1) were stronger than that of model group, and the difference was statistically significant. HE staining and Hoechst33258 staining showed that compared with the control group, the number of cells in the model group was significantly less, and the cell morphology was incomplete. Compared with the model group, the number of cells in the treatment group was significantly increased, and the cell morphology was better. The results of JC-1 assay showed that the number of apoptotic cells in the model group was significantly higher than that in the control group, and the number of apoptotic cells in the treatment group was significantly lower than that in the model group. DCFH-DA staining showed that the ROS accumulation in the model group was more than that in the control group, and the ROS accumulation in the treatment group was less than that in the model group. Immunostaining observation showed that the HO-1 fluorescence intensity of the cells in the treatment group was significantly higher than that of the control group, and the difference was statistically significant (t=10.270, P=0.000 5). Western blot analysis showed that NBP up-regulated the expression level of HO-1 in a time-dependent manner. The relative expression of HO-1 at 4, 8, and 12 h of NBP showed a clear increase trend compared with 0 h, and the difference was statistically significant (F=164.91, P＜0.05).ConclusionsOxidative stress injury can down-regulate the viability of RPE cells and induce apoptosis. NBP can increase the antioxidant capacity of RPE cells, reduce cell damage and inhibit cell apoptosis by up-regulating HO-1 expression.
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.