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Objective:To observe the effect of high expression of polypyrimidine tract-binding protein-associated splicing factor (PSF) on low concentration of 4-hydroxynonenal (4-HNE) induced human retinal microvascular endothelial cells (HRMECs), and explore the possible mechanism.Methods:The HRMECs cultured in vitro were divided into 4-HNE treated group, PSF overexpression group combined with 4-HNE group (PSF+4-HNE group), PSF overexpression+ML385 treatment combined with 4-HNE group (PSF+ML385+4-HNE group), and 4-HNE induced PSF overexpression group with LY294002 pretreatment (LY294002+4-HNE+PSF group). Cell culture medium containing 10 μmmol/L 4-HNE was added into 4-HNE treatment group, PSF+4-HNE group, PSF+ML385+4-HNE group for 12 hours to stimulate oxidative stress. 1.0 μg of pcDNA-PSF eukaryotic expression plasmid were transfected into PSF+4-HNE group and PSF+ML385+4-HNE group to achieve the overexpression of PSF. Also cells were pretreated with ML385 (5 μmol/L) for 48 hours in the PSF+ML385+4-HNE group, meanwhile within the LY294002+4-HNE+PSF group, after pretreatment with LY294002, cells were treated with plasmid transfection and 4-HNE induction. Transwell detects the migration ability of PSF to HRMECs. The effect of PSF on the lumen formation of HRMECs was detected by using Matrigel in vitro three-dimensional molding method. Flow cytometer was used to detect the effect of PSF overexpression on reactive oxygen (ROS) level in HRMECs. Protein immunoblotting was used to detect the relative expression of PSF, nuclear factor E2 related factor 2 (Nrf2), heme oxygenase-1 (HO-1) protein, and phosphoserine threonine protein kinase (pAkt) protein. The comparison between the two groups was performed using a t-test. Results:The number of live cells, migrating cells, and intact lumen formation in the 4-HNE treatment group and the PSF+4-HNE group were 1.70±0.06, 0.80±0.13, 24.00±0.58, 10.00±0.67, and 725.00±5.77, 318.7±12.13, respectively. There were significant differences in the number of live cells, migrating cells, and intact lumen formation between the two groups ( t=12.311, 15.643, 17.346; P<0.001). The results of flow cytometry showed that the ROS levels in the 4-HNE treatment group, PSF+4-HNE group, and PSF+ML385+4-HNE group were 816.70±16.67, 416.70±15.44, and 783.30±17.41, respectively. There were statistically significant differences between the two groups ( t=16.311, 14.833, 18.442; P<0.001). Western blot analysis showed that the relative expression levels of pAkt, Nrf2, and HO-1 proteins in HRMECs in the 4-HNE treatment group, PSF+4-HNE group and LY294002+4-HNE+PSF group were 0.08±0.01, 0.57±0.04, 0.35±0.09, 0.17±0.03, 1.10±0.06, 0.08±0.11 and 0.80±0.14, 2.50±0.07, 0.50±0.05, respectively. Compared with the PSF+4-HNE group, the relative expression of pAkt, Nrf2, and HO-1 proteins in the LY294002+4-HNE+PSF group decreased significantly, with significant differences ( t=17.342, 16.813, 18.794; P<0.001). Conclusion:PSF upregulates the expression of HO-1 by activating the phosphatidylinositol 3 kinase/Akt pathway and inhibits cell proliferation, migration, and lumen formation induced by low concentrations of 4-HNE.
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Objective:To investigate the effect of polypeptide N-acetylgalactosaminaminyltransferase 2 (GALNT2) on the proliferation and apoptosis of human retinal vascular endothelial cells (HRCECs) cultured in high glucose and its possible mechanism.Methods:The small hairpin RNA (shRNA) targeting GALNT2 gene was constructed to interfere with the lentiviral vector and infect HRCECs.HRCECs were divided into blank control group, model group, NC-shGALNT2 group and shGALNT2 group, which were cultured in medium containing 5.5 mmol/L glucose, 25 mmol/L glucose, shGALNT2 negative control virus 25 mmol/L glucose and shGALNT2 knockdown virus 25 mmol/L glucose for 24 hours, respectively.The relative expression of GALNT2 mRNA in the four groups was detected by real-time fluorescence quantitative PCR.The relative expression levels of GALNT2, epidermal growth factor (EGF), EGF receptor (EGFR) and phosphorylated EGFR (p-EGFR) were detected by Western blot.The proliferative values of HRCECs were detected by cell counting kit-8 method.The apoptosis rate of different groups was detected by flow cytometry. Results:The relative expression levels of GALNT2 mRNA and protein were significantly higher in model group than in blank control group, and were significantly lower in shGALNT2 group than in blank control group (all at P<0.05). The cell proliferation value was significantly lower in model group than in blank control group, and was significantly higher in shGALNT2 than in model group and NC-shGALNT2 group (all at P<0.05). The apoptosis rates of blank control group, model group, NC-shGALNT2 group and shGALNT2 group were (4.73±0.26)%, (8.66±0.25)%, (9.26±1.12)% and (5.47±0.18)%, respectively, with a significant overall difference ( F=342.921, P<0.001). The apoptosis rate was significantly higher in model group than in blank control group, and was significantly lower in shGALNT2 group than in model group and NC-shGALNT2 group (all at P<0.05). The relative expression level of EGFR protein was significantly higher and the relative expression level of p-EGFR protein was significantly lower in model group than in blank control group (all at P<0.05). The relative expression of p-EGFR protein was significantly higher in shGALNT2 group than in model group (all at P<0.05). Conclusions:Knocking down GALNT2 can improve the proliferative ability of HRCECs under high glucose culture and reduce apoptosis, which may be related to the activation of EGFR signaling pathway.
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@#AIM: To explore the effect of dapagliflozin on the apoptosis and oxidative stress of high glucose-induced human retinal vascular endothelial cells and its regulatory effect on forkhead FOXO4. <p>METHODS: High glucose-induced human retinal vascular endothelial cells(HRVECs)were used to establish a cell injury model(high glucose group). Experimental groups include high glucose+dapagliflozin low-dose group(1ng/L dapagliflozin), high glucose+dapagliflozin medium-dose group(5ng/L dapagliflozin), high glucose+dapagliflozin high-dose group(10ng/L dapagliflozin), high glucose+dapagliflozin high-dose+pcDNA group, high glucose+dapagliflozin high-dose+pcDNA-FOXO4 group, and normal sugar group(5.5mmol/L D-glucose). Flow cytometry was used to detect the apoptosis rate. The levels of superoxide dismutase(SOD)and malondialdehyde(MDA)were tested with corresponding kits. Western blot assay was used to detect the protein level of FOXO4. <p>RESULTS: Compared with the normal sugar group, the apoptosis rate(<i>P</i><0.05), the level of MDA(<i>P</i><0.05)and FOXO4(<i>P</i><0.05)were increased, but the level of SOD was decreased(<i>P</i><0.05)in high-glucose group. Compared with the high glucose group, cell apoptosis rate(<i>P</i><0.05), the level of MDA(<i>P</i><0.05)and the protein level of FOXO4 were decreased(<i>P</i><0.05), but the level of SOD was increased(<i>P</i><0.05)in high glucose+medium-dose dapagliflozin group and high glucose+high-dose dapagliflozin group. Compared with high glucose+dapagliflozin high-dose+pcDNA group, the apoptosis rate(<i>P</i><0.05)and the level of MDA(<i>P</i><0.05)were increased, but the level of SOD was decreased(<i>P</i><0.05)in high glucose+dapagliflozin high-dose+pcDNA-FOXO4 group(<i>P</i><0.05). <p>CONCLUSION: Dapagliflozin could inhibit oxidative stress and cell apoptosis in high glucose-induced HRVECs by down-regulating FOXO4, thereby reducing cell damage.
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[Objective] To observe NGF on cultured human retinal vascular endothelial cells (HRCEC) proliferation. [Methods] The MTT assay was used to analyze the impact of culture HRCEC on different factors (NGF concentration groups, NGF + K252a concentration groups, bFGF group, bFGF + K252a groups, the normal culture medium groups) in normal and hypoxic condition. [Results] With the increase of NGF concentration (20,50,100 ng/mL), HRCEC significantly increased (normal condition: 0.254±0.033,0.696±0.029, 1.136±0.051; hypoxic condition: 0.422±0.036, 0.798±0.044, 1.376±0.052, P< 0.05). Compared NGF + K252a group with the same concentration of NGF (100 ng/ml) group, HRCEC reduced (P<0.05), with increasing the concentration of K252a (50,100,200 nmol/L), the trend of HRCEC decreasing is become more significant (normal condition:0.864±0.067, 0.496±0.025, 0.202±0.078; hypoxic condition:K252a 1.042±0.047,0.700±0.065, 0.401±0.078, P<0.05). [Conclusion] NGF can promote the proliferation of HRCEC, the effect could be specifically blocked by TrkA inhibitor K252a.