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AIM: To investigate the effect of inhibiting Ca2+/calmodulin-dependent protein kinase Ⅱ(CAMKⅡ)expression in adult retinal pigment epithelial cell line-19(ARPE-19)cells on the migration, invasion, and tube formation of human umbilical vein endothelial cells(HUVECs)in a non-contact co-culture system.METHODS: RNA sequencing was performed on ARPE-19 cells overexpressing CAMKⅡ-δ, and bioinformatics was used to analyze the biological functions of the differentially expressed genes. Transwell inserts was used to construct a non-contact co-culture system of ARPE-19 and HUVECs. The experimental groups included: blank group: only HUVECs were inoculated without ARPE-19 cells; control group: ARPE-19 and HUVECs cells were co-cultured with complete medium; AIP group(CAMKⅡ inhibition group): ARPE-19 cells in AIP(160 nmol/L)were co-cultured with HUVECs in complete medium. The migration, invasion and tube formation abilities of HUVECs were detected. The protein expression levels of CAMKⅡ/AMPK/mTOR/VEGFA were detected by Western blotting.RESULTS:Bioinformatics analysis found that the differentially expressed genes could affect biological processes such as cell growth and death and cell movement. The scratch test and transwell migration test showed that the relative mobility of HUVECs in the AIP group was significantly lower than that in the control group(all P<0.05). However, the invasion and tube formation assay showed that the relative invasion rate and tube formation rate of the AIP group were not significantly different from those of the control group(both P>0.05). Western blotting results showed that the expression levels of CAMKⅡ, P-mTOR, and VEGFA proteins in the AIP group were significantly lower than those in the control group, while the expression level of the P-AMPK protein was significantly higher than that in the control group(all P<0.05).CONCLUSION:In the non-contact co-culture system, inhibition of CAMKⅡ expression in ARPE-19 cells significantly reduced the migration ability of HUVECs, but it cannot change the invasion and tube formation ability, which may be achieved by AMPK/mTOR/VEGFA.
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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 investigate the antagonistic effect and potential mechanism of specific AKT activator SC79 on the apoptosis of human retinal pigment epithelial (ARPE)-19 cells induced by high glucose in vitro. Methods:The ARPE-19 cells were cultured in high glucose medium (containing 30 mmol/L glucose) plus 5, 10 or 20 μg/ml SC79, respectively.After 6-, 12- and 24-hour culture, the optimal experimental concentration and timing were determined according to cell proliferation rate.Then ARPE-19 cells were divided into four groups, normal control group cultured in normal medium containing 5.6 mmol/L glucose for 48 hours, mannitol group cultured in medium containing 5.6 mmol/L glucose and 24.4 mmol/L mannitol for 48 hours, high glucose group cultured in high glucose medium for 48 hours, and high glucose+ SC79 group cultured in normal medium containing 10 μg/ml SC79 for 12 hours plus in high glucose medium for 36 hours.The proliferation rate of APRE-19 cells was detected by MTS assay.The apoptosis rate was measured by flow cytometry.The relative expression levels of phosphorylated protein kinase B (p-Akt), X-linked inhibitor of apoptosis protein (XIAP), caspase-9, caspase-3 and its active fragments (active-caspase-3) were assayed by Western blot.The ARPE-19 cells were divided into Neg-shRNA group, AKT shRNA group and blank control group and were treated with the corresponding transfection complex and serum-free medium.The AKT mRNA expression was detected by real-time PCR.The transfected ARPE-19 cells were divided into Neg-shRNA+ SC79 group and AKT shRNA+ SC79 group and were cultured according to the culturing method of high-glucose+ SC79 group.The apoptosis rate of the two groups was tested by flow cytometry.Results:Among different concentrations of SC79 and treatment times, the proliferation rate of cells treated with 10 μg/ml SC79 for 12 hours was the highest.The proliferation rate of ARPE-19 cells in high-glucose group was significantly lower than that in normal control group, mannitol group and high-glucose+ SC79 group, and the differences were statistically significant (all at P<0.01). The apoptosis rate of cells in the high-glucose group was (52.27±3.21)%, which was significantly higher than (3.90±0.71)% in normal control group and (20.70±3.62)% in high-glucose+ SC79 group (both at P<0.01). The relative expression levels of p-Akt, XIAP, caspase-9 and caspase-3 were significantly lower and the relative expression level of active-caspase-3 was significantly higher in high glucose group than those in normal control group and high-glucose+ SC79 group (all at P<0.05). The relative expression level of AKT mRNA in normal control group, Neg-shRNA group and AKT shRNA group was 0.60±0.07, 0.59±0.03 and 0.11±0.10, respectively, showing a statistically significant difference among the groups ( F=30.44, P<0.01). The apoptosis rate of cells in the AKT shRNA+ SC79 group was significantly higher than that in high-glucose+ SC79 group and Neg-shRNA+ SC79 group (both at P<0.001). Conclusions:SC79 can partially antagonize the apoptosis of ARPE-19 cells induced by high glucose, which is related to the activation of AKT/XIAP pathway and the inhibition of the caspase family.
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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 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 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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@#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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Age-related macular degeneration (AMD) is one of the main causes of vision loss among middle-aged and elderly people worldwide. The prevention and treatment of AMD is a current topic of interest in ophthalmology but remains challenging. Oxidative stress-induced retinal pigment epithelial cell autophagic dysfunction, cellular senescence, and an abnormal immune inflammatory response are key pathogenic factors for AMD. Many bioactive ingredients of traditional Chinese medicine not only exert anti-oxidative, anti-inflammatory, anti-aging, and anti-apoptotic effects, but also prevent/block the occurrence of AMD through different pathways. This review summarizes our current understanding of the pathogenesis of AMD, the types of natural bioactive ingredients capable of treating AMD, as well as the known mechanisms by which these agents act, and may provide new strategies for the prevention and treatment of AMD.
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@#AIM: To compare the efficacy of conbercept and ranibizumab on neovascular age-related macular degeneration(nARMD)of type 1 macular neovascularization(MNV)with fibrovascular pigment epithelial detachment(fPED).<p>METHODS: Retrospective clinical study. From January 2019 to December 2020, 48 patients(48 eyes)of nARMD type 1 MNV patients with fPED diagnosed in our hospital were included and divided into conbercept group with 26 patients(26 eyes)and ranibizumab group with 22 patients(22 eyes)according to the drugs they received. All patients received treatment of 3+PRN. Followed up for 12mo, the best corrected visual acuity(BCVA)of the two groups was observed, and optical coherence tomography(OCT)was used to measure the macula foveal thickness(CFT)and the regression degree(height, area, volume)of retinal pigment epithelial detachment(PED).<p>RESULTS: There was no significant difference between two groups in BCVA, CFT and PED height, area and volume before treatment(<i>P</i> >0.05). The PED height of the two groups was significantly improved at 3, 6 and 12mo after the first intravitreal injection treatment compared with those before treatment(<i>P</i><0.05). But the PED area and volume were not significantly improved(<i>P</i>>0.05). There was no significant improvement in BCVA between the two groups after treatment compared with those before treatment(<i>P</i>>0.05). The CFT of the conbercept group was significantly improved at 3, 6 and 12mo after treatment compared with those before treatment(<i>P</i><0.05), and the ranibizumab group improved significantly only 3mo after treatment(<i>P</i><0.05). There were no significant differences in BCVA, CFT, and PED height, area and volume between the two groups at 3, 6 and 12mo after treatment(<i>P</i> >0.05).<p>CONCLUSION: The conbercept and ranibizumab have good effects on type 1 MNV with fPED in nARMD, which can reduce the PED height and CFT, and stabilize the visual acuity, PED area and volume. However, conbercept can achieve longer reduction of macular edema.
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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 explore the multimodal imaging features of butterfly-like retinal pigment epithelial dystrophy(BPD)patients.<p>METHODS: Retrospective analysis of the multimodal imaging of 18 BPD patients(36 eyes)from January 2016 to July 2019, including fundus color photography, infrared photography, autofluorescence, fundus fluorescein angiography, indocyanine green angiography, optical coherence tomography(OCT), and optical coherence tomography angiography(OCTA). <p>RESULTS: A typical fundus color photography showed the appearance of a butterfly-like lesion caused by abnormal pigmentation. The appearance of the butterfly was not obvious after the lesion progressed, and the corresponding region shrinks; Infrared photography showed the yellow lesions clearly in the BPD patients, which are white highlight images; Autofluorescence showed patchy, spotted butterfly wing performance. When the lesion progressed, autofluorescence did not show typical butterfly changes, but it showed the damage of pigment epithelial cells; Fundus fluorescein angiography and choroidal angiography, in addition to showed butterfly lesions, can more accurately display vascular lesions, especially choroidal neovascularization(CNV); OCT showed lesions located between the retinal pigment epithelial(RPE)layer and the photoreceptors. As the lesion progressed, the pigment epithelium showed enlarged lesions correspondingly. Secondary CNV patients can be seen to break RPE; OCTA showed that the lesions were not obvious at the deep and superficial layers of the retina. But the choroidal blood flow signals were lost in some degrees in OCTA, and the blood flow images of CNV can be detected sensitively.<p>CONCLUTION: Multimode imaging technology can provide imaging features of progression in BPD patients, which helps clinicians to understand the disease more deeply.
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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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@#AIM: To investigate the synthesis method of curcumin nanoparticles grafted with deoxycholic acid and the effect of curcumin nanoparticles on human retinal pigment epithelial(hRPE)cells. <p>METHODS: The synthesis and performance analysis of Cur/Chit-DC. The relationship between FITC/Chit-DC and hRPE cells was observed under an inverted fluorescence microscope after treating hRPE cells with FITC(FITC/Chit-DC)and Cur/Chit-DC(FITC/Cur/Chit-DC)for 24h, keeping them in dark for 1, 3 and 5d respectively.<p>RESULTS: By mixing Cur and Chit-DC, the nanoparticles containing chitosan derivatives were light yellow. The drug release from the nanoparticles reached equilibrium after 96h, and the cumulative drug release amount was 31.6%. After FITC/Chit-DC was treated with hRPE cells for 1d, most of Chit-DC nanoparticles were still located near the cell membrane. After 3d, the nanoparticles gradually converged towards the nucleus and most of them were located around the nucleus. After 5d, it was observed that Chit-DC nanoparticles had entered the nucleus and were partially degraded under the action of intracellular lysosomes. The relationship between Cur/Chit-DC and cellular action is roughly the same as the relationship between Chit-DC and cellular action. <p>CONCLUSION: Cur can be continuously released from Cur/Chit-DC nanoparticle, which has long-lasting sustained-release function.
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@#AIM: To investigate the effects of simvastatin(Sim)on human retinal pigment epithelial cells(RPE-19)and the possible mechanisms <i>in vitro</i> under hypoxia. <p>METHODS: RPE-19 cells were divided into three group: control group, hypoxia group(the final concentration of CoCl2 in the medium was 125 μmol/L), and Sim treatment group(3 μmol/L Sim was added in the RPE cells' medium which contain 125 μmol/L CoCl2). After 24h, the morphology of RPE-19 cells were observed, the proliferation of cells were calculated by MTT, the secretion levels and protein expression of hypoxia-inducible factor 1-Alpha(HIF-1α)and vascular endothelial growth factor(VEGF)were detected by enzyme-linked immunosorbent assay(ELISA)and Western blotting. The expression level of autophagy protein was detected by Western blot and apoptosis was detected by TUNEL.<p>RESULTS: The morphology and activity of RPE-19 cells showed an apparent change under hypoxia. The expression of HIF-1α and VEGF protein were increased obviously in the hypoxia group and then significantly decreased after Sim treatment. Beclin1, and LC3B proteins were decreased in the CoCl2+Sim group, and the expression levels were lower than the control and CoCl2 group. Under hypoxia, Sim inhibited RPE cells' proliferation and promoted the apoptosis.<p>CONCLUSION:Sim inhibits RPE cells' proliferation, decreases HIF-1α and VEGF protein, and promotes apoptosis under hypoxia. Our results suggested that the mechanism by which Sim promoted apoptosis in RPE cells may be related to its inhibition of autophagy.
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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 serious complication arisen from ocular trauma, diabetic retinopathy, vascular retinopathy, inflammatory retinopathy and other ocular diseases. It is also the most important reason for the failure of rhegmatogenous retinal detachment surgery, which is a great threat of visual function. A large number of studies have proved that the main risk factor for PVR is the damage of blood-retinal barrier, in which retinal pigment epithelial(RPE)cells are stimulated by cytokines in the vitreous cavity. RPE cells underwent epithelial-mesenchymal transition(EMT), which transformed into fibroblasts. The cell morphology changed, the tight junctions between cells disappeared, the cell polarity lost, and the proliferation, migration, and invasion abilities were enhanced. A contractile fibrous proliferative membrane is formed on the anterior surface or under the retina. The fibrous proliferative membrane will lead to the retina folds, pull the retina and lead to retinal detachment, which will eventually lead to vision loss or even blindness. Nowadays, plenty of studies investigating the prevention and treatment of PVR have been carried out at home and abroad. In this review, we briefly illustrated the signaling pathways related to epithelial-mesenchymal transformation in RPE cells and the treatment of PVR.
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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.