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Objective:To observe and preliminarily explore the effect of mogroside on oxidative stress of retinal pigment epitheliaum (RPE) cells induced by hydrogen peroxide (H 2O 2) and its possible mechanism. Methods:A experimental study. The RPE cells were divided into control group, H 2O 2 group, silent information regulator of transcription 1 (SIRT1) inhibitor EX527 group (EX527 group), mogroside group, mogroside+EX527 group. Methyl thiazolete trazolium method was used to detect cell survival rate. Flow cytometry was used to detect cell apoptosis rate. 2' ,7'-dichlorodihydrofluorescein diacetate fluorescent probe method, xanthine method and enzyme-linked immunosorbent assay method were used to detect the level of reactive oxygen species (ROS), superoxide dismutase (SOD) activity and malondialdehyde (MDA) content in cells respectively. Real-time quantitative polymerase chain reaction and Western blot were used to detect relative expressions of SIRT1, nuclear factor erythroid-2-related actor 2 (Nrf2), heme oxygenase-1 (HO-1) mRNA and protein in cells. One-way ANOVA was used for comparison among groups. The pairwise comparison between groups was tested by the least significant difference t test. Results:Compared with the control group, the H 2O 2 group cell survival rate decreased, the apoptosis rate increased, the ROS level in the cells increased, the SOD activity decreased, the MDA content increased, and the relative expression of SIRT1, Nrf2, HO-1 mRNA and protein decreased ( P<0.05). Compared with H 2O 2 group, the cell survival rate decreased, apoptosis rate increased, the cell ROS level increased, SOD activity decreased, MDA content increased, SIRT1, Nrf2, HO-1 mRNA and protein expression decreased in EX527 group ( P<0.05); the cell survival rate increased, apoptosis rate decreased, ROS level decreased, SOD activity increased, MDA content decreased, and the relative expression of SIRT1, Nrf2, HO-1 mRNA and protein increased in mogroside group ( P<0.05). Compared with the mogrosides group, the cell survival rate decreased, the apoptosis rate increased, the level of ROS increased, SOD activity decreased, MDA content increased, SIRT1, Nrf2, HO-1 mRNA and protein decreased in mogrosides+EX527 group ( P<0.05). Conclusions:Mogrosides can alleviate the oxidative stress response of visual RPE cells induced by H 2O 2, promote cell proliferation, and reduce cell apoptosis. Mogrosides may exert antioxidant effects by activating the SIRT1/Nrf2 signaling pathway.
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Objective:To study the effect of ZhuJing pill variant formula medicated serum on hydrogen peroxide (H 2O 2)-induced epithelial-mesenchymal transition (EMT) of human retinal pigment epithelial (ARPE-19) cells and its mechanism. Methods:Thirty female SPF grade SD rats aged 2 months old were selected.The rats were randomized into blank control group and Zhujing pill variant formula group according to random number table method, with 15 in each group, which were intragastrically administered with normal saline and ZhuJing pill variant formula solution for 7 days accordingly to prepare blank control serum and medicated serum.ZhuJing pill variant formula medicated serum was prepared with SD rats.ARPE-19 cells were divided into normal control group, model control group, blank serum group as well as 2.5%, 5.0% and 10.0% medicated serum groups, SB216763 group and SB216763+ medicated serum group.Normal and blank control groups were cultured in normal culture medium, while the other six groups were cultured in blank rat serum medium, medicated serum medium of corresponding concentration, 10 μmol/L SB216763 medium and 10 μmol/L SB216763+ 10.0% medicated serum medium, respectively.Normal control group was routinely cultured, while the other groups were routinely cultured for 24 hours, and then added with H 2O 2 with the final concentration of 200 μmol/L for 24 hours.Cell viability was assessed by cell counting kit-8 (CCK-8) assay, and cell migration ability was detected by Transwell assay.Intracellular reactive oxygen species (ROS) level was detected by dichloro-dihydro-fluorescein diacetate (DCFH-DA) assay, and MDA level was identified by sulfhydryl barbituric acid assay.The expression levels of Nrf2 pathway related proteins including nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), quinone oxidoreductase 1 (NQO-1) and EMT-related proteins including transforming growth factor-β2 (TGF-β2), protein kinase B (AKT), glycogen synthase kinase-3β (GSK-3β), snail family zinc finger 1 (SNAIL1), α-smooth muscle actin (α-SMA), epithelial cadherin (E-cadherin) in cells were measured by western blot assay.The use and care of animals complied with Regulations for the Administration of Affairs Concerning Experimental Animals. Results:There was no significant difference in cell survival rate among blank serum group, 2.5%, 5.0% and 10.0% medicated serum groups ( F=0.163, P>0.05). The cell survival rates were (100.50±5.91)%, (60.87±4.30)%, (73.27±4.46)%, (80.73±5.67)% and (89.90±4.97)% in normal control group, model control group, 2.5%, 5.0% and 10.0% medicated serum groups, and the number of migrating cells was (84.67±8.33), (222.33±13.58), (215.67±10.02), (174.67±10.60), (143.67±8.02) and (107.67±6.66) pcs/visual field in normal control group, model control group, blank serum group, 2.5%, 5.0% and 10.0% medicated serum groups, respectively, with significant differences among the groups ( F=26.628, 99.289; both at P<0.01). The contents of ROS and MDA in model control group were significantly increased in comparison with normal control group (both at P<0.01). The contents of ROS and MDA of 2.5%, 5.0% and 10.0% medicated serum groups were significantly decreased in comparison with model control group (all at P<0.01). The relative expression levels of SNAIL1, α-SMA, TGF-β2, p-AKT and p-GSK-3β proteins were significantly higher and the relative expression level of E-cadherin protein was significantly lower in model control group compared with normal control group, 2.5%, 5.0% and 10.0% medicated serum groups (all at P<0.05). Compared with normal control group, the relative expression level of cytoplasmic Nrf2 in model control group was decreased, while the relative expression levels of nuclear Nrf2, HO-1 and NQO-1 were increased, and the differences were statistically significant (all at P<0.05). Compared with model control group, the relative expression levels of cytoplasmic Nrf2 in 2.5%, 5.0% and 10.0% medicated serum groups were reduced, and the relative expression levels of nuclear Nrf2, HO-1 and NQO-1 were enhanced, and the differences were statistically significant (all at P<0.01). Compared with model control group, the relative expression level of cytoplasmic Nrf2 in SB216763 group was decreased, and the relative expression level of nuclear Nrf2 was increased, and the differences were statistically significant (both at P<0.05). Compared with SB216763 group, the relative expression levels of cytoplasmic Nrf2, SNAIL1 and α-SMA in SB216763+ medicated serum group were decreased, and the relative expression levels of nuclear Nrf2 and E-cadherin protein were increased, and the differences were statistically significant (both at P<0.05). Conclusions:ZhuJing pill variant formula medicated serum can inhibit H 2O 2-induced EMT in ARPE-19 cells.The mechanism may be related to the inhibition of AKT/GSK-3β pathway and the activation of Nrf2 signaling pathway.
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@#AIM: To investigate the potential toxic effects of paclitaxel(PTX)on the proliferation, apoptosis, cell cycle, morphology, and blood-retinal barrier(BRB)of human retinal pigment epithelial cells(ARPE-19). <p>METHODS: ARPE-19 cells were cultured <i>in vitro</i> and divided into two groups: Control group(Control)and drug plus group(PTX). ARPE-19 cells were treated with different concentrations of PTX(0.005, 0.05, 0.5, 5mg/L)for a certain period of time(12, 24, 36, 48, 72h), and CCK8 assay and flow cytometry were used to detect the effects of drug on proliferation and apoptosis of ARPE-19 cells at different concentrations and time points. The same time, the cell cycle was detected by flow cytometry. Morphological changes of cells were observed by immunofluorescence. Expressions of apoptosis-related proteins and barrier function-related proteins were detected by Western blot. The effect of the drug on the cell barrier was measured by measuring the transepithelial resistance of the cells. <p>RESULTS: PTX reduced the proliferation ability of ARPE-19 cells. After 36h of treatment with low concentration of 0.005mg/L paclitaxel, cell proliferation began to be affected. At the same time, PTX accelerated cell apoptosis was dependent on drug concentration and time. Flow cytometry showed that the cells were arrested in the G2-M phase. In addition, PTX causes significant morphological changes in cells, with normal cells fusiform or irregular. In the PTX group, the number of cells decreased and the cell shape tended to be round. PTX affected retinal barrier function, and the transepithelial resistance of cells was significantly decreased after treatment, and the expression of tight junction proteins ZO-1 and Occludin were significantly decreased compared with the control group(<i>P</i><0.05). The expression levels of Cleaved-caspase-3 and Bax were significantly increased compared with the control group, while the expression levels of Bcl-2 were significantly decreased(<i>P</i><0.05)and was dependent on drug concentration and time. <p>CONCLUSION: PTX can affect the proliferation and apoptosis of ARPE-19 cells, and it depends on time and concentration. In addition, PTX affected the cell cycle and morphology of ARPE-19 cell. At the same time PTX can destroy the barrier function of the retina,suggesting that anti-tumor drugs have a potential toxic effect on the retina.
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@#AIM:To study the effect of vitamin E on the injury of human retinal pigment epithelial(hRPE)cells induced by high-dose blue light, and provide experimental evidence for intercepting blue light damaged hRPE cells. <p>METHODS: The hRPE cell injury model was established with 3000±150Lx blue light. The apoptosis rate and reactive oxygen species(ROS)of the six groups of hRPE cells were detected by flow cytometry at 0, 3, 6, 9, 12 and 24h respectively. Apoptosis and ROS in hRPE cells were detected by cytometry in 0h-irradiation group, 6h-irradiation group, and vitamin E added groups(vitamin E concentration 10, 50, 100μmol/L)before or after 6h-irradiation. The fluorescence intensity of hRPE cells was observed under a fluorescence microscope using Hoechst 33258 staining reagent.<p>RESULTS: Compared with the 0h-irradiation group, the relative amount of reactive oxygen species increased significantly in 3, 6, 9, 12 and 24h groups(all <i>P</i><0.01), the apoptosis rate of hRPE cells increased significantly in 6, 9, 12 and 24h groups(all <i>P</i><0.01), the apoptosis rate of the 3h-irradiation group was not statistically significantly increased(<i>P</i>=0.46). Compared with the 6h-irradiation group, the relative amounts of ROS and apoptotic rate of the six groups of hRPE cells added vitamin E were significantly decreased, and the blue fluorescence of Hoechst 33258 released in the cells gradually decreased, which was concentration dependent(all <i>P</i><0.01),except for apoptosis rate of hRPE cells in the 10 μmol/L vitamin E group before irradiation(<i>P</i>=0.66). Compared with the 0h-irradiation group, the difference in the relative amount of ROS and apoptosis rate of hRPE cells in added groups were statistically significant(all <i>P</i><0.01). At the same concentration of vitamin E, the relative amount of ROS and apoptosis rate of hRPE cells added vitamin E after irradiation were significantly lower than those added vitamin E before irradiation(all <i>P</i><0.01), except for apoptosis rate of hRPE cells in the 10 μmol/L vitamin E group, which had no difference between added before and after irradiation(<i>P</i>=0.08).<p>CONCLUSION: After hRPE cells had been irradiated by blue light, the increase in the relative amount of intracellular ROS was earlier than that of apoptosis. Elimination of intracellular ROS is the idea of intercepting high doses of blue light induced hRPE cell injury. Vitamin E protects RPE cell against damage induced by high doses of blue light, and the effect becomes stronger as the concentration of vitamin E increases, which is better when added after irradiating. However, it doesn't take effect until the concentration reaches a certain level. And the damage can't be completely repaired.
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@#Proliferative vitreoretinopathy(PVR)is a eye disease characterized by the formation of epiretinal membranes(ERM)composed of extracellular matrix(ECM)and various types of cells in the vitreous and/or the surface of the retina through the wound repair and fibrotic process. ERM shrinks to form retinal folds and stretches the retina to cause retinal detachment(RD). Epithelial-mesenchymal transition(EMT)of retinal pigment epithelial(RPE)cells and accumulation of ECM are considered to be the main pathological mechanisms for the formation of ERM. RPE cells undergo a process named EMT induced by transforming growth factor-β(TGF-β), by which differentiated epithelial cells go through epithelial phenotypic loss, the weakness of cell-cell contact and mesenchymal phenotype expression. Fibroblast-like cells differentiated from mesenchymal cells produce ECM and other components, which forms ERM together with glial cells and fibroblasts, <i>etc</i>. Recent studies indicated a lot of cytokines/growth factors, transcriptional factors, and microRNA(miRNA)regulate the development of EMT in RPE cells, in which miRNA is a novel and powerful regulatory gene and plays a critical regulatory role in the EMT process of PVR. This review focuses on the current understandings of the mechanism and the interventional treatments of miRNA in PVR.
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AIM:To investigate whether ceramide kinase-like protein(CERKL)alleviates oxidative stress injury of retinal pigment epithelial(RPE)cells induced by blue light via activating the silent information regulator 1(SIRT1)/E2F transcription factor 1(E2F1)axis. METHODS:Cultured human retinal pigment epithelial-19(ARPE-19)cells were irradiated with blue light to observe the morphological changes, and the expression of CERKL was detected by PCR and Western blot. ARPE-19 cells were transfected with siRNA-CERKL and pcDNA3.1-CERKL respectively. After exposure to blue light, cell viability was determined by MTT assay, apoptosis was detected by TUNEL assay, content of oxidative stress markers and the expression of SIRT1/E2F1 axis was analyzed. Then siRNA-SIRT1 was transfected into ARPE-19 cells, and the oxidative stress damage of ARPE-19 cells under blue light irradiation was detected again.RESULTS:ARPE-19 cells gradually contracted into spheres and appeared vacuoles after exposure to blue light. Blue light irradiation led to the increase of CERKL expression level(P<0.05), meanwhile, the rate of cell viability was decreased(P<0.05), the rate of the apoptosis was increased(P<0.05), contents of reactive oxygen species, malondialdehyde and 8-hydroxydeoxyguanosine were increased(P<0.05). Silence of CERKL aggravated this phenomenon, while up-regulation of CERKL could alleviate this change(P<0.05). Up-regulation of CERKL also activated the expression of SIRT1 and promoted the deacetylation of E2F1(P<0.05). Silencing SIRT1 could reverse the alleviating effect of up-regulating CERKL on oxidative stress injury of ARPE-19 cells induced by blue light(P<0.05). CONCLUSION: CERKL can reduce oxidative stress damage of ARPE-19 cells induced by blue light via activating SIRT1 expression and promoting the deacetylation of E2F1.
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Objective:To observe the influence of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) 4 inhibitors on epithelial-mesenchymal transition (EMT) of human retinal pigment epithelial (RPE) cells induced by bevacizumab.Methods:The cultured ARPE-19 cells were divided into blank control group, bevacizumab group, bevacizumab+ VAS2870 group and bevacizumab+ GKT137831 group.Cells were cultured with 0.25 g/L bevacizumab, 0.25 g/L bevacizumab plus 3 μmol/L VAS2870 (a NOX4 inhibitor), 0.25 g/L bevaczumab plus 20 μmol/L GKT137831 (a NOX4 inhibitor) for 72 hours according to grouping.No intervention was administered to the blank control group.The mRNA and protein expression levels of NOX4 and EMT markers including fibronectin (FN), vimentin, α-smooth muscle actin (α-SMA) and tight junction related protein zonula occludens-1 (ZO-1) were measured by real-time PCR and Western blot assay, and the expression levels in different intervention groups were compared.The expressions of NOX4 and EMT markers were verified by immunofluorescence staining.Results:There were statistically significant differences in the relative mRNA and protein expression levels of FN, vimentin, α-SMA, ZO-1 and NOX4 among blank control group, bevacizumab group, bevacizumab+ VAS2870 group and bevacizumab+ GKT137831 group (mRNA: F=97.07, 195.40, 722.40, 38.56, 70.81; all at P<0.001.Protein: F=23.09, 64.58, 58.19, 26.97, 63.19; all at P<0.001). The relative mRNA and protein expression levels of FN, vimentin, α-SMA and NOX4 were significantly higher and the relative mRNA and protein expression level of ZO-1 was significantly lower in bevacizumab group than those in blank control group (all at P<0.05). The relative mRNA and protein expression levels of FN, vimentin, α-SMA and NOX4 were significantly lower and the relative mRNA and protein expression levels of ZO-1 were significantly higher in bevacizumab+ VAS2870 and bevacizumab+ GKT137831 groups than those in bevacizumab group (all at P<0.05). The immunofluorescence intensity of FN, vimentin and α-SMA was stronger and the immunofluorescence intensity of ZO-1 was weaker in bevacizumab group than blank control group.The immunofluorescence intensity of FN, vimentin and α-SMA were weaker and the immunofluorescence intensity of ZO-1 was stronger in bevacizumab+ VAS2870 group and bevacizumab+ GKT137831 group than those in bevacizumab group. Conclusions:NOX4 is involved in the bevacizumab-induced EMT of human RPE cells, the degree of which can be reduced by NOX4 inhibitors.
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@#AIM: To study the protective effect of astragalus-containing serum on cobalt chloride(CoCl2)-induced hypoxia injury of human retinal pigment epithelial cells(ARPE-19), so as to explore whether astragalus can improve diabetic retinopathy(DR)by anti-oxidative stress.<p>METHODS: The ARPE-19 hypoxia model induced by CoCl2 was established and divided into the following 5 groups: normal group(cells were cultured normally without any treatment), hypoxia model group(200μmol/L CoCl2), blank serum group(200μmol/L CoCl2+blank serum), low-dose drug-containing serum group(200μmol/L CoCl2+10% medicated serum)and high-dose drug-containing serum group(200μmol/L CoCl2+20% medicated serum); CCK-8 detects cell viability; Detect the levels of reduced glutathione(GSH)and malondialdehyde(MDA)in the cell supernatant with a kit; ELISA was used to detect the content of hypoxia-inducible factor-1α(HIF-1α)and vascular endothelial growth factor(VEGF)in cell culture medium; Real-time quantitative PCR(qPCR)to detect the mRNA levels of VEGF, HIF-1α and Prolyl hydroxylase-2(PHD-2); The expressions of VEGF, HIF-1α and PHD-2 were detected by Western Blot.<p>RESULTS: Hypoxia model of ARPE-19 can successfully establish by CoCl2 at 200μmol/L. Low-dose and high-dose astragalus-containing serum could inhibit hypoxia-induced ARPE-19 proliferation(<i>P</i><0.05), increase the GSH level and reduce the MDA content in ARPE-19 with hypoxic injury(<i>P</i><0.05). Low-dose and high-dose astragalus-containing serum could inhibit the expression of HIF-1α and VEGF in ARPE-19 hypoxic injury supernatant(<i>P</i><0.05), as well as the mRNA and protein expressions of VEGF, HIF-1α and PHD-2 in ARPE-19(<i>P</i><0.05).<p>CONCLUSION: Low-dose and high-dose astragalus-containing serum alleviates the hypoxia injury of ARPE-19 induced by CoCl2 through anti-oxidant effect.
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@#AIM: To investigate the effect and mechanism of curcumin on inhibiting choroidal neovascularization(CNV)<i>in vitro</i>. METHODS: Human retinal pigment epithelial(ARPE-19)cells chemical hypoxia model was established by cobalt chloride(CoCl2). CCK-8 method was used to detect the effect of curcumin on the activity of ARPE-19 cells induced by CoCl2. RT-qPCR and Western blot were used to detect the expression of AKT, HIF-1α, VEGF mRNA and protein in ARPE-19 cells hypoxia model induced by CoCl2. Cell scratch test, transwell chamber migration test, transwell chamber invasion test and matrigel matrix hose lumen formation test were used to observe the effects of conditioned medium of curcumin in ARPE-19 cells on the proliferation, migration, invasion and lumen formation of human umbilical vein endothelial cells(HUVEC)in non-contact condition. RESULTS:Chemical hypoxia model of ARPE-19 cells can successfully establish by CoCl2 at 100μmol/L. CoCl2 at the final concentration of 100μmol/L can promote the expression of AKT, HIF-1α and VEGF mRNA and p-AKT, HIF-1α and VEGF protein in ARPE-19 cells. Curcumin at the final concentration of 100μmol/L can reduce the expression of AKT, HIF-1α and VEGF mRNA in ARPE-19 hypoxia model. Curcumin at the final concentration of 100μmol/L can reduce the expression of AKT, HIF -1α and VEGF proteins in ARPE-19 hypoxia model. The conditioned medium of low(6.25μmol/L), medium(25μmol/L)and high dose(100μmol/L)curcumin in ARPE-19 cells can significantly inhibit the level migration of HUVEC. The conditioned medium in high dose group can significantly inhibit the vertical migration and cell invasion of HUVEC. The conditioned medium of middle and high dose curcumin in ARPE-19 cells can inhibit the lumen formation of HUVEC. CONCLUSION:Curcumin at 100μmol/L can protect ARPE-19 cells from hypoxia induced by CoCl2. Curcumin can inhibit the formation of blood vessels at the cellular level.
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Objective:To investigate all-trans retinoic acid(ATRA)-induced apoptosis signaling pathway in ARPE-19 cells in vitro. Methods:The APRE-19 cell was treated with different concentrations of ATRA for 24 hours and 48 hours.Cell counting kit-8 (CCK-8) was used to detect the cell viability in order to determine the experimental concentration range.Flow cytometry and Western blot method were performed to evaluate the apoptosis and caspase related protein levels in ARPE-19 cells treated with 0, 2.5, 5, 10, 15 and 20 μmol/L of ATRA for 24 hours.Flow cytometry was used to detect the reactive oxygen species (ROS) and multicaspase levels and quantitative real-time PCR was carried out to determine the mRNA relative expression levels of caspase related proteins in ARPE-19 cells treated with 0, 2.5, 5, 10 and 20 μmol/L of ATRA, and 0 μmol/L ATRA group was used as the blank control group.Results:CCK-8 test showed that the half maximal inhibitory concentration of ARPE-19 cells treated with different concentrations of ATRA for 24 hours and 48 hours were 13.88 μmol/L and 11.99 μmol/L, respectively.The cell survival rates of ARPE-19 cells treated with different concentrations of ATRA for 24 hours and 48 hours were significantly different ( F=176.60, 350.30; both at P<0.01). When cultured for 24 hours, the cell survival rates of ARPE-19 cells in the 2 μmol/L and 6 μmol/L of ATRA groups were higher than that of the blank control group (both at P<0.05), and the cell survival rates of ARPE-19 cells in the 12, 14, 16, 18 and 20 μmol/L of ATRA groups were lower than that of the blank control group (all at P<0.05). Flow cytometry showed that there were significant differences in the apoptosis, ROS and multicaspase level among ARPE-19 cell groups treated with different concentrations of ATRA ( F=86.39, 116.84, 101.40; all at P<0.01). The apoptosis rates of APRE-19 cells in the 2.5 μmol/L and 5 μmol/L of ATRA groups were significantly decreased than that of the blank control group, and the apoptosis rate of APRE-19 cells in the 10, 15 and 20 μmol/L of ATRA groups were significantly increaseded than that of the blank control group (all at P<0.01). The relative expression levels of multicaspase and ROS were significantly higher in the 2.5, 5, 10 and 20 μmol/L of ATRA groups than that of the blank control group (all at P<0.01). Western blot assay showed that the relative expression level of caspase 9 was increased in the 2.5, 5, 10, 15 and 20 μmol/L of ATRA groups than that of the blank control group (all at P<0.05). Compared with the blank control group, the relative expression levels of caspase 12 were increased in the 2.5 μmol/L of ATRA group and reduced gradually in the 5, 10, 15 and 20 μmol/L of ATRA groups, among which there were significant differences between the blank control group and 2.5, 15, and 20 μmol/L of ATRA groups (all at P<0.05). The relative expression level of caspase 3 was significantly increased in the 5, 10 and 20 μmol/L of ATRA groups than that of the blank control group (all at P<0.05). The relative expression level of cleaved caspase 3 was significantly increased in the 2.5, 5, 10, 15 and 20 μmol/L of ATRA groups than that of the blank control group (all at P<0.01). Quantitative real-time PCR assay showed that the relative expression levels of caspase 9 and caspase 12 mRNA were significantly higher in the 2.5, 5, 10 and 20 μmol/L of ATRA groups than that of the blank control group (all at P<0.01). The relative expression levels of caspase 3 mRNA were significantly higher in the 5 μmol/L and 10 μmol/L of ATRA groups than that of the blank control group (both at P<0.01). When the concentration of ATRA was lower than 10 μmol/L, the relative expression levels of caspase 9 and caspase 12 mRNA were elevated in a concentration-dependent manner.When the concentration of ATRA reached 20 μmol/L, the relative expression levels of caspase 9 and caspase 12 mRNA were markedly decreased, but it was still higher than that of the blank control group. Conclusions:ATRA induces apoptosis in ARPE-19 cells in vitro through activating the reactive oxygen species and endogenous caspase-dependent apoptotic pathway.
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@#AIM: To study the histological and ultrastructural changes of mouse retina after exposure to e-cigarette and the potential mechanism.<p>METHODS: Totally 18 male c57BL mice aged 8-week-old were divided into control group(<i>n</i>=6), 0mg nicotine group(<i>n</i>=6)and 12mg nicotine group(<i>n</i>=6). The histological and ultrastructural changes of retina were evaluated by hematoxylin and eosin(HE)staining and transmission electron microscope(TEM), respectively. Additionally, the expression of Tuj1 and 8-OHdG was examined using immunofluorescent staining. <p>RESULTS: In comparison with control group, the thickness of whole retina, nerve fiber layer(NFL)and inner plexiform layer(IPL)was significantly decreased in experimental groups(0mg and 12mg nicotine group)(<i>P</i><0.01), but no significant difference was observed between 0mg and 12mg nicotine group(<i>P</i>>0.05). The dramatically reduced microvilli of RPE cells were also observed in experimental groups using TEM. Furthermore, residual microvilli were shortened. The expression of Tuj1 was decreased in ganglion cell layer(GCL), NFL and IPL, but no significant changes in the number of retinal ganglion cells were shown among three groups(<i>P</i>>0.05). In addition, the increased expression of 8-OHdG was observed in GCL and inner nuclear layer(INL)in experimental groups.<p>CONCLUSION: E-cigarette can lead to the retinal damages in mice, which might be due to oxidative stress.
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@#AIM: To investigate the effect of miRNA-147 targeted regulation of vascular endothelial growth factor(VEGF)on the proliferation, apoptosis and migration of human retinal pigment epithelial cells, and to explore its molecular mechanism. <p>METHODS: Human retinal pigment epithelial(ARPE-19)cells were selected and divided into 7 groups: blank control group(untreated), nonsense miRNA group(transfected with mimic NC), miRNA-147 simulant group(transfected with miRNA-147 mimic), inhibitor negative control group(transfected with shRNA NC), VEGF inhibitor group(transfected with shRNA VEGF), miRNA-147 simulant+empty viral vector group(transfected with miRNA-147 mimic and pcDNA3.1)and miRNA-147 simulant+VEGF overexpression group(transfected with miRNA-147 mimic and pcDNA3.1 VEGF). RT-qPCR was used to detect the expression of miRNA-147 and VEGF mRNA. Dual luciferase experiments were used to verify the targeting relationship between miRNA-147 and VEGF. Western blot was used to detect the expression of VEGF protein. MTT method was used to detect the proliferation. Flow cytometry to detect the apoptosis level and cell cycle changes. Cell scratch test to detect the level of cell migration. <p>RESULTS: Compared with the blank control group and the nonsense miRNA group, the expression level of miRNA-147 in miRNA-147 simulant group was significantly increased, while the expression levels of VEGF mRNA and protein were significantly reduced(<i>P</i><0.05). Compared with the inhibitor negative control group, the expression levels of VEGF mRNA and protein in the VEGF inhibitor group were significantly reduced(<i>P</i><0.05). Compared with the miRNA-147 simulant+empty viral vector group, the expression level of VEGF mRNA in the miRNA-147 simulant+VEGF overexpression group was significantly increased(<i>P</i><0.05). The dual luciferase report shows that VEGF is the target gene of miRNA-147. Transfection of miRNA-147 mimic and shRNA VEGF can reduce the proliferation and migration of ARPE-19 cells and promote apoptosis can reduce the proliferation and migration of ARPE-19 cells and promote apoptosis(<i>P</i><0.05). Transfection VEGF overexpression reverses the effect of miRNA-147 mimics on proliferation, migration and apoptosis of ARPE-19 cells(<i>P</i><0.05). <p>CONCLUSION: miRNA-147 can inhibit ARPE-19 cell proliferation, migration and promote cell apoptosis by targeting VEGF.
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@#Age-related macular degeneration(ARMD)is a major cause of irreversible loss of central vision in the elderly. Typical characteristics of ARMD consist of retinal pigment epithelium(RPE), degenerative changes of choroidal capillaries and vitreous warts in macular area. Clinical ARMD is divided into two subtypes: non effusive(dry or atrophic)and effusive(wet or neovascular). The occurrence of the disease is the result of the interaction of many factors, such as age, environment, heredity, smoking, oxidative stress and cardiovascular dysfunction, <i>etc</i>. In view of the important role of RPE cells in pathogenesis of ARMD, the effects and possible mechanisms of blue light, smoking, oxidative stress, lipofuscin accumulation, chronic inflammation and protein homeostasis on the onset of dry ARMD are summarized by focusing on RPE cells. This will provide new ideas to help understand and prevent the occurrence of dry ARMD.
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@#AIM: To investigate the endoplasmic reticulum stress(ERS)induced by all-trans retinoic acid(ATRA)in ARPE-19 cells.<p>METHODS:Immunofluorescence, real-time quantitative polymerase chain reaction and Western blot were used to detect the protein and mRNA expression of related signal pathways during the process of endoplasmic reticulum stress response induced by ATRA in ARPE-19 cells.<p>RESULTS: With the accumulation of ATRA concentration, the protein and mRNA levels of endoplasmic reticulum stress response marker proteins chop and BiP were significantly increased(<i>P</i><0.001); in the downstream signaling pathways, perk, eIF2 α, ATF4, IRE1 α and XBP1 were up-regulated(<i>P</i><0.001), while the expression of ATF6 did not change(<i>P</i>>0.05).<p>CONCLUSION: Over accumulation of ATRA induces ERS in ARPE-19 cells and activates PERK-EIF2 α-ATF4 and IRE1 α-XBP1 signaling pathways
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@#AIM: To explore the effect of lycium barbarum polysaccharides(LBP)on inflammatory response of human retinal pigment epithelial cells(ARPE-19)induced by lipopolysaccharide(LPS)and its possible signal pathway.<p>METHODS: ARPE-19 cells were stimulated by LPS <i>in vitro</i> to construct the inflammatory injury cell model. Primarily, the cells were divided into five groups randomly. The blank group was cultured in complete medium, and the LPS group was stimulated with complete medium containing 10μg/mL LPS for 24h. The low, medium and high concentration LBP groups were incubated with complete medium importing 0.1, 0.5 and 1mg/mL LBP for 24h separately, and then stimulated with complete medium containing 10μg/mL LPS for 24h. We used the CCK-8 method to observe the cell survival rate, real-time fluorescent quantitative PCR to detect the mRNA expression of inflammatory factors and Western blot to test the changes of phosphorylated protein within the signaling pathway of NF-κB/MAPK.<p>RESULTS: Compared with normal cells, the survival rate of ARPE-19 cells was decreased after the LPS stimulation. With the increase of exogenous LBP concentration, the survival rate of ARPE-19 cell was gradually increased, while the inflammatory factors expression of cytokines IL-1β, IL-6 and MCP-1 were reduced accompany with the phosphorylated proteins(p-p65, P-IκBα, p-JNK, p-ERK and p-p38)of NF-κB/MAPK signaling pathway were decreased.<p>CONCLUSION: LBP prevents LPS-induced inflammatory response of ARPE-19 by inhibiting the intracellular inflammatory factors and the phosphorylation of the related protein within NF-κB/MAPK signaling pathway.
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@#Retinal degenerative disease can lead to decreased vision, which is a blinding ophthalmopathy caused by irreversible damage or apoptosis of retinal pigment epithelium(RPE)cells or photoreceptor cells, often resulting in visual impairment or even blindness. Human embryonic stem cells(hESCs)are a kind of multi-directional differentiation cells. By appropriate methods, hESCs can be differentiated into various retinal cells. Since human PRE cells cannot be regenerated, studies have shown that the clinical treatment of retinopathy with stem cell derived RPE cell transplantation has practical prospects and has made a breakthrough in recent years. Due to the limitations of multiple factors, the selection of methods and the complexity of induction conditions, the efficiency of induced differentiation of RPE and the survival rate after transplantation vary greatly and are unstable. Therefore, the current researches should focus on how to integrate different culture methods, take advantages and eliminate disadvantages, so as to improve the directed differentiation efficiency of hESCs, as well as the number and quality of induced cells, thus reducing culture pollution and immune rejection and so on. Here, we will summarize the current examples of various culture methods and give a review from different perspectives.
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@#AIM: To observe the effects of high glucose-induced environment on Visfatin expression in human retinal pigment epithelial cells and to study the effects of Polyphyllin I on Visfatin expression in high glucose environment. <p>METHODS: Human retinal pigment epithelial cells were cultured in three groups, normal control group, high glucose group and intervention group of high glucose aggravated PolyphyllinⅠ, testing after 12h of intervention culture. Normal control group:5.5mmol/L glucose concentration routine culture; high glucose group:25mmol/L high glucose was added to the medium to establish the model; high glucose aggravated PolyphyllinⅠdrug intervention group: high glucose 25mmol/L, 3μg/L PolyphyllinⅠdrug was added to the medium. Immunofluorescence staining assays to observe expression of the Visfatin and VEGF in human retinal pigment epithelial cells; real-time PCR assays for relative expression of Visfatin and VEGF mRNA in epithelial cells; and western-blot assays for Visfatin and VEGF proteins in epithelial cells. <p>RESULTS: Immunofluorescence detection revealed that Visfatin and VEGF were weakly positive in normal retinal pigment epithelial cells. Visfatin and VEGF were strongly positive in high glucose group. Visfatin and VEGF fluorescence in the drug intervention group was significantly weakened in the higher sugar group. RT-PCR showed that the expression level visfatin mRNA high sugar group was significantly higher than that of normal group and intervention group(<i>t</i>=4.24, 3.89, <i>P</i><0.05). VEGF mRNA expression was significantly higher in high glucose group than in normal group and intervention group(<i>t</i>=3.53, 2.57, <i>P</i><0.05). Western-blot results showed that the protein expression of visfatin and VEGF in high sugar group was significantly higher than that in control group and intervention group(<i>t</i>=3.62, <i>P</i>=0.01; <i>t</i>=3.79, <i>P</i><0.01). <p>CONCLUSION: The high glucose environment can stimulate the increased expression of Visfatin in retinal pigment epithelial cells, Polyphyllin I can inhibit the expression of Visfatin in retinal pigment epithelial cells in high glucose environment, which may provide a new idea for the treatment of diabetic retinopathy.
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@#In recent years, stem cell research and application in the field of ophthalmology has been highlighted, embryonic stem cells and adult stem cells can be targeted induced to differentiate into retinal pigment epithelial cells(RPE cells), which can obtain transdifferentiation of RPE cells source, through the body stem cells and retinal pigment epithelium cells transplantation is expected to be used in a variety of alternative treatment of the degenerative diseases of the retina. In this paper, the methods and application of various stem cells induced differentiation into RPE cells were discussed.
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AIM: To study the protective effects and mechanism of resveratrol (RES) on the injury of human retinal pigment epithelial cells (ARPE-19) induced by high glucose (HG). METHODS: ARPE-19 cells were cultured in HG to simulate injury. Cell viability, apoptosis, ROS generation and miR-26a level were examined by CCK-8 assay, flow cytometry assay, DCFH-DA staining and RT-qPCR, respectively. Expression of proteins associated with viability, apoptosis and oxidative stress was measured by Western blot analysis. In addition, the involvements of the ERK and Wnt/β-catenin pathways were analyzed by Western blot analysis.RESULTS:HG reduced cell viability while promoted apoptosis and oxidative stress in ARPE-19 cells. RES ameliorated HG-induced cell injury. The expression of miR-26a was up-regulated by RES in HG-treated cells, and miR-26a inhibition obviously reversed the effects of RES on HG-treated cells. Finally, we found the ERK and Wnt/β-catenin pathways were inhibited by RES through up-regulation of miR-26a. CONCLUSION: RES protected ARPE-19 cells against HG-induced injury through up-regulating miR-26a, along with inhibition of the ERK and Wnt/β-catenin pathways. RES might be a potential therapeutic drug for diabetic retinopathy.
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Objective@#To investigate the protective effect of human umbilical cord mesenchymal stem cells (UCMSCs) on light-damaged retinal pigment epithelial (RPE) cells in vitro.@*Methods@#Human UCMSCs were cultured, and then identified by flow cytometry.Human RPE cells were isolated and cultured, and then the model of light-damaged RPE cells was prepared.The noncontact co-culture system of light-damaged RPE cells and UCMSCs was established by Transwell chamber.RPE cells were divided into normal control group, model control group and UCMSCs co-culture group.RPE cells in the normal control group were not treated.RPE cells in the model control group were treated with blue light to induce RPE cell damage.Co-culture system of light-damaged RPE cells and UCMSCs was established in the UCMSCs co-culture group.The proliferative ability of RPE cells was measured by methyl thiazolyl tetrazolium (MTT) assay at 24 hours and 48 hours after co-culture.ELISA kits were used to quantitatively measure the levels of pigment epithelium-derived factor (PEDF) and basic fibroblast growth factor (bFGF) in the culture supernatant at 48 hours after co-culture.And the photoreceptor outer segments (POS) phagocytosis assay of RPE cells was also conducted.@*Results@#UCMSCs displayed spindle-shaped morphology, positively expressed CD29, CD44, CD90 and CD105, while negatively expressed CD34 and CD45.RPE cells were polygonal in morphology and positive for the specific marker RPE65 protein.The proliferative ability(A value) of RPE cells in the three groups at different timepoints were significantly different (Fgroup=132.388, P=0.000; Ftime=231.440, P=0.000), the A values of RPE cells in model control group and UCMSCs co-culture group were significantly lower than that in the normal control group, the A value of RPE cells in UCMSCs co-culture group was significantly higher than that in the model control group, and the differences were statistically significant both at 24 hours and 48 hours after co-culture (all at P<0.01). POS phagocytosis test showed that there was a significant difference in the average number of POS particles phagocytized by RPE cells among the three groups(F=28.087, P=0.000). The average number of POS particles phagocytized by RPE cells in model control group was significantly lower than that in normal control group, and the average number of POS particles phagocytized by RPE cells in UCMSCs co-culture group was significantly more than that in model control group (all at P<0.01). ELISA showed that the concentrations of PEDF in RPE cell supernatant of normal control group, model control group and UCMSCs co-culture group were (18.8±1.9), (10.0±1.7) and (20.2±6.0)ng/ml, respectively.The concentrations of bFGF in RPE cell supernatant were (25.2±1.5), (26.3±3.6) and (61.9±14.3)pg/ml, respectively.There were significant differences in PEDF and bFGF concentrations among the three groups (F=8.654, P=0.008; F=23.698, P=0.000). The concentration of PEDF in the model control group was significantly lower than that in the normal control group, and the concentration of PEDF in the UCMSCs co-culture group was significantly higher than that in the model control group (all at P<0.01). The concentration of bFGF in UCMSCs co-culture group was significantly higher than that in the normal control group and model control group (all at P<0.01).@*Conclusions@#Cocultivation with UCMSCs can improve the proliferation ability and phagocytosis function of light-damaged RPE cells, and promote the secretion of PEDF by RPE cells.UCMSCs may protect RPE cells from light damage through paracrine secretion of bFGF.