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.
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.
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.
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 observe the effects of overexpression of polypyrimidine tract binding protein-associated splicing factor (PSF) on the endoplasmic reticulum (ER) oxidative stress damage of human retinal microvascular endothelial cells (hRMEC) under high concentration of 4-hydroxynonenal (4-HNE). MethodsThe logarithmic growth phase hRMEC cultured in vitro was divided into normal group, simple 4-HNE treatment group (simple 4-HNE group), empty plasmid combined with 4-HNE treatment group (Vec+4-HNE group), and PSF high expression combined with 4-HNE treatment group (PSF+4-HNE group). In 4-HNE group, Vec+4-HNE group, and PSF+4-HNE group cell culture medium, 10 μmol/L 4-HNE was added and stimulated for 12 hours. Subsequently, the Vec+4-HNE group and PSF+4-HNE group were transfected with transfection reagent liposome 2000 into pcDNA empty bodies and pcDNA-PSF eukaryotic expression plasmids, respectively, for 24 hours. Flow cytometry was used to detect the effects of 4-HNE and PSF on cell apoptosis. The effect of PSF overexpression on the expression of reactive oxygen species (ROS) in hRMEC was detected by 2', 7'-dichlorodihydrofluorescein double Acetate probe. Western blot was used to detect ER oxide protein 1 (Ero-1), protein disulfide isomerase (PDI), C/EBP homologous transcription factor (CHOP), glucose regulatory protein (GRP) 78, protein kinase R-like ER kinase (PERK)/phosphorylated PERK (p-PERK), and Eukaryotic initiation factor (eIF) 2α/the relative expression levels of phosphorylated eIF (peIF) and activated transcription factor 4 (ATF4) proteins in hRMEC of normal group, 4-HNE group, Vec+4-HNE group, and PSF+4-HNE group. Single factor analysis of variance was performed for inter group comparison. ResultsThe apoptosis rates of the simple 4-HNE group, Vec+4-HNE group, and PSF+4-HNE group were (22.50±0.58)%, (26.93±0.55)%, and (11.70±0.17)%, respectively. The intracellular ROS expression levels were 0.23±0.03, 1.60±0.06, and 0.50±0.06, respectively. The difference in cell apoptosis rate among the three groups was statistically significant (F=24.531, P＜0.05). The expression level of ROS in the Vec+4-HNE group was significantly higher than that in the simple 4-HNE group and the PSF+4-HNE group, with a statistically significant difference (F=37.274, P＜0.05). The relative expression levels of ER Ero-1 and PDI proteins in the normal group, simple 4-HNE group, Vec+4-HNE group, and PSF+4-HNE group were 1.25±0.03, 0.45±0.03, 0.63±0.03, 1.13±0.09, and 1.00±0.10, 0.27±0.10, 0.31±0.05, and 0.80±0.06, respectively. The relative expression levels of CHOP and GRP78 proteins were 0.55±0.06, 1.13±0.09, 0.90±0.06, 0.48±0.04 and 0.48±0.04, 1.25±0.03, 1.03±0.09, 0.50±0.06, respectively. The relative expression levels of Ero-1 (F=43.164), PDI (F=36.643), CHOP (F=42.855), and GRP78 (F=45.275) proteins in four groups were compared, and the differences were statistically significant (P＜0.05). Four groups of cells ER p-pERK/pERK (F=35.755), peIF2 α/ The relative expression levels of eIF (F=38.643) and ATF4 (F=31.275) proteins were compared, and the differences were statistically significant (P＜0.05). ConclusionPSF can inhibit cell apoptosis and ROS production induced by high concentration of 4-HNE, and its mechanism is closely related to restoring the homeostasis of ER and down-regulating the activation level of PERK/eIF2α/ATF4 pathway.
Objective To investigate the effect of Nodal protein on retinal neovascularization under hypoxia. MethodsIn vivo animal experiment: 48 healthy C57BL/6J mice were randomly divided into normal group, oxygen-induced retinopathy (OIR) group, OIR+dimethyl sulfoxide (DMSO) group and OIR+SB431542 group, with 12 mice in each group. Retinal neovascularization was observed in mice at 17 days of age by retina flat mount. Counts exceeded the number of vascular endothelial nuclei in the retinal inner boundary membrane (ILM) by hematoxylin eosin staining. In vivo cell experiment: human retinal microvascular endothelial cells (hRMEC) were divided into normal group, hypoxia group, hypoxia+DMSO group and hypoxia +SB431542 group. The cell proliferation was detected by thiazolyl blue colorimetry (MTT). The effect of SB431542 on hRMEC lumen formation was detected by Matrigel three-dimensional in vitro molding method. Cell migration in hRMEC was detected by cell scratch assay. The Seahorse XFe96 Cell Energy Metabolism analyzer measured extracellular acidification rate (ECAR) of intracellular glycolysis, glycolysis reserve, and glycolysis capacity. One-way analysis of variance was used to compare groups. ResultsIn vivo animal experiment: compared with normal group, the neovascularization increased in OIR group (t=41.621, P＜0.001). Compared with OIR group, the number of vascular endothelial nuclei breaking through ILM in OIR+SB431542 group was significantly reduced, and the difference was statistically significant (F=36.183, P＜0.001). MTT test results showed that compared with normal group and hypoxia+SB431542 group, the cell proliferation of hypoxia group and hypoxia+DMSO group was significantly increased, and the difference was statistically significant (F=39.316, P＜0.01). The cell proliferation of hypoxia+SB431542 group was significantly lower than that of hypoxia+DMSO group, and the difference was statistically significant (t=26.182, P＜0.001). The number of intact lumen formation and migration cells in normal group, hypoxia group, hypoxia+DMSO group and hypoxia+SB431542 group were statistically significant (F=34.513, 41.862; P＜0.001, ＜0.01). Compared with the hypoxia+DMSO group, the number of intact lumen formation and migrating cells in the hypoxia+SB431542 group decreased significantly, and the differences were statistically significant (t=44.723, 31.178; P＜0.001, ＜0.01). The results of cell energy metabolism showed that compared with the hypoxia +DMSO group, the ECAR of intracellular glycolysis and glycolysis reserve in the hypoxia +SB431542 group was decreased, and the ECAR of glycolysis capacity was increased, with statistical significance (t=26.175, 33.623, 37.276; P＜0.05). ConclusionSB431542 can inhibit the proliferation, migration and the ability to form lumens, reduce the level of glycolysis of hRMECs cells induced by hypoxia.
ObjectiveTo observe the inhibitory effect of lentivirus (LV)-mediated miR-191 on the proliferation and angiogenesis of human retinal vascular endothelial cells (hREC) cultured in vitro.MethodsThe hREC cell lines were cultured in vitro and divided into control group, hypoxia group, LV-empty vector (LV-vector) group, and LV-miR-191 (LV-191) group. The LV-vector group and LV-191 group were transferred to the corresponding lentiviral vector respectively. Flow cytometry was used to detect cell transfection efficiency. Cell Counting Kit-8 (CCK-8) test was used to detect cell proliferation ability. Scarification test and invasion chamber (Transwell) test were used to detect cell migration ability. Matrigel test was used to detect cell lumen formation ability. Real-time quantitative polymerase chain reaction (qPCR) was used to detect the relative expression of miR-191 and relative mRNA expression of its downstream target genes p21, vascular endothelial growth factor (VEGF), cell division protein kinase (CDK) 6, cyclin-D1 (Cyclin D1). Independent sample t test was used for pairwise comparison. ResultsThe results of flow cytometry showed that the transfection efficiency of cells in the control group and the LV-191 group were 0.615% and 99.400%, respectively. The results of CCK-8, scarification, Transwell and Matrigel test showed that, compared with the control group, the number of cell proliferation (t=6.130, 4.606), the cell mobility (t=4.910, 6.702), the number of stained cells on the microporous membrane (t=7.244, 6.724) and the lumen formation ability cells (t=8.345, 9.859) were significantly increased in the hypoxia group and the LV-vector group (P<0.01), while the LV-191 group showed completely opposite performance (t=14.710, 6.245, 5.333, 5.892; P≤0.01). The qPCR test results showed that, compared with the control group and the LV-vector group, the relative expression of miR-191 mRNA in the cells of the LV-191 group was significantly up-regulated (t=44.110, 42.680), the relative expression of Cyclin D1 mRNA (t=29.940, 14.010) and CDK6 mRNA (t=15.200, 7.645) decreased significantly, and the difference were statistically significant (P<0.01); the relative expression of p21 mRNA increased, however, the difference was not statistically significant (t=2.013, 2.755; P>0.05). There was no significant difference in the relative expression of VEGF mRNA in the 4 groups of cells (F=0.966, P>0.05). ConclusionsLV-191 can inhibit the proliferation, migration and tubing of hREC by up-regulating p21 and down-regulating CDK6 and Cyclin D1.
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.