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.