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.
ObjectiveTo observe RNA-Seq analysis of gene expression profiling in retinal vascular endothelial cells after anti-vascular endothecial growth factor (VEGF) treatment.MethodsRetinal vascular endothelial cells were cultured in vitro, and the logarithmic growth phase cells were used for experiments. The cells were divided into the control group and high glucose group. The cells of two groups were cultured for 5 hours with 5, 25 mmol/L glucose, respectively. And then, 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, 449 DEGs were found, including 297 upregulated and 152 downregulated ones. The functions of DEGs were influenced by regulations over molecular biological process, cellular energy metabolism and protein synthesis, etc. Among these genes, ITGB1BP2, NCF1 and UNC5C were related to production of inflammation; AKR1C4, ATP1A3, CHST5, LCTL were related to energy metabolism of cells; DAB1 and PRSS55 were related to protein synthesis; SMAD9 and BMP4 were related to the metabolism of extracellular matrix. GO enrichment analysis showed that DEGs mainly act in three ways: regulating biological behavior, organizing cellular component and performing molecular function, which were mainly concentrated in the system generation of biological process part and regulation of multicellular organisms. Pathway enrichment analysis showed that gene expressions of the two cell groups were differentiated in transforming growth factor-β (TGF-β) signaling pathway, complement pathway and amino acid metabolism-related pathways have also been affected, such as tryptophan, serine and cyanide. Among them, leukocyte inhibitory factor 9 and bone morphogenetic protein 4 play a role through the TGF-β signaling pathway.ConclusionsHigh glucose affects the function of retinal vascular endothelial cells by destroying transmembrane conduction of retinal vascular endothelial cells, metabolism of extracellular matrix, and transcription and translation of proteins.
Objective To observe the synergistic effect of metformin and anti-vascular endothelial growth factor (VEGF) in the treatment of diabetic retinopathy. Methods This study was composed of clinical data review and in vitro cell experiment. Ten patients (12 eyes) with diabetic macular edema treated with anti-VEGF drugs were included in the study. Patients were randomly divided into the VEGF group (anti-VEGF drug therapy) and the combined treatment group (anti-VEGF drug combined with metformin). The changes of visual acuity and central retinal thickness (CRT) were compared between the two groups. As far as the in vitro experiment was concerned, vascular endothelial cells were divided into the control group (normal cells), the VEGF group (50 ng/ml VEGF), the anti-VEGF group (50 ng/ml VEGF+2.5 μg/ml of conbercept), and the combined group (50 ng/ml VEGF +2.5 μg/ml of conbercept +2.0 mmol/L of metformin). And then MTT cell viability assay, scratch assay and real-time quantitative polymerase chain reaction assay were performed to analyze the cell viability, cell migration and mRNA level of VEGFR2, protein kinase C (PKC)-α and PKC-β successively. ResultsReview of clinical trial shows that the CRT recovery rates in the combined treatment group were much higher than that in the VEGF group at 3 month after the operation, while the difference was statistically significant (t=−2.462, P＜0.05). In vitro cell experiment results showed that VEGF induction upregulated the viability and mobility of vascular endothelial cells obviously compared with control group, at the same time, the use of anti VEGF drugs can effectively reverse the trend, in contrast, combination of metformin and anti-VEGF showed a more superior effect to some extent (P＜0.05). In the VEGF group, the mRNA expression of VEGFR2, PKC-αand PKC-β were significantly increased compared with the control group (P＜0.01); while the mRNA expression of VEGFR2, PKC-αand PKC-β in the combination group decreased significantly compared with the VEGF group and the control group (P＜0.05). However, in the anti-VEGF group, the mRNA expression of VEGFR2, PKC-αand PKC-β were decreased, but has failed to reach the level of statistical learn the difference. ConclusionsThe combination of metformin and anti-VEGF drugs can reduce the CRT of diabetic retinopathy patients and inhibit the proliferation and migration of retinal vascular endothelial cells which induced by VEGF. The synergistic mechanism may be related to the inhibitory effect of metformin on the expression of VEGFR and PKC.
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.