O-linked N-acetylglucosamine (O-GlcNAc) glycosylation is an important form of post-translational protein modification, mainly intracellular. It is closely related to cellular signaling pathways, and is involved in signal transduction, gene transcription and other important biological processes. Studies have found that O-GlcNAc glycosylation is directly related with diabetic retinopathy (DR), further studies may help us to uncover the DR mechanism, and develop new strategies for the diagnosis and treatment of this disease.
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.
The exact pathophysiological mechanisms of diabetic retinopathy (DR) remain elusive. The inflammatory reaction, retinal vascular leakage and retinal neovascularization are main features of DR. Adiponectin (APN) is an endogenous biological active protein secreted by adipocytes. It can increase insulin sensitivity, regulate blood glucose and lipid metabolism, and has anti-inflammation and anti-neovascularization functions. It may be involved in the development of DR. This review summarized the studies on the association between APN and DR in recent years.
It is clear that genetic background contributes to the development and progression of diabetic retinopathy (DR). However, the identification of susceptibility loci through candidate gene approaches, linkage disequilibrium analysis of case-control data and genome wide association study is still in its infancy and faces many challenges due to the complexity of the disease itself. China has rich resources of clinical samples. In order to facilitate elucidating the susceptibility genes of DR in China, we look forward multi-disciplinary, multi-regional collaboration studies integrating novel technologies, such as proteomics, metabolomics and next-generation sequencing to analyze gene-gene and gene-environment interaction factors comprehensively.
ObjectiveTo investigate the expression of miR-195 and the underlying molecular mechanisms of miR-195 regulating HMGB1 in diabetic retinopathy (DR). MethodsExtract 5 ml venous blood from DR patients, diabetes mellitus (DM) patients and normal subjects, then extract and perificate plasma total RNA. MicroRNA array and real time polymerase chain reaction (RT-PCR) was used to screen out miRNAs which were expressed with significant differences in the serum of patients with DR. Bioinformatics was employed to predict the miR-195 related to high mobility group box 1 (HMGB1) regulation. Next, miR-195 was down-regulated or up-regulated in umbilical vein endothelial cells through transfection of miR-195 inhibitor and miR-29b mimics respectively.Then we analyzed expression of HMGB1 mRNA and protein by RT-PCR and Western blot. ResultsMicroRNA array results showed the expression of miR-195 in DR group is decreased by 8.34 times and 11.47 times compared with DM group and the normal group. RT-PCR verification results conforms to the microRNA array results. Compared with the DM group (F=0.034, t=8.057) and the normal group (F=0.370, t=9.522), the expression of miR-195 in DR group were significantly reduced, the differences were statistically significant (P < 0.05). RT-PCR showed that the expression of HMGB1 mRNA was significantly decreased in up-regulation group, compared with blank (F=0.023, t=11.287) and negative control group (F=0.365, t=7.471), the difference was statistically significant (P < 0.05). The expression of HMGB1 mRNA was significantly increased in down-regulation group, compared with blank (F=0.053, t=10.871) and negative control group (F=0.492, t=6.883), the difference was statistically significant (P < 0.05). Western blot showed that the expression of HMGB1 protein was significantly decreased in up-regulation group, compared with blank (F=0.021, t=8.820) and negative control group (F=0.039, t=7.401), the difference was statistically significant (P < 0.05); and significantly increased in down-regulation group, compared with blank (F=0.186, t=10.092) and negative control group (F=0.017, t=12.923), the difference was statistically significant (P < 0.05). ConclusionMiR-195 can inhibit the expression of HMGB1, reduce the inflammation and angiogenesis, thereby delaying or inhibiting the occurrence and development of DR.