Effects of travoprost on actin cytoskeleton and β-catenin in the human trabecular meshwork cells treated with Dexamethasone

Objective To investigate the effect of travoprost on changes of actin cytoskeletal and β-catenin protein in the cultured human trabecular meshwork (HTM) cells treated with dexamethasone (DEX). Methods It was a control experiment study. The HTM cells were cultured in vitro and divided into control group, DEX (1 × 10-6mol/L) group, travoprost (1 × 10-6mol/L) group, and DEX (1 ×10-6mol/L) plus travoprost (1 × 10-6mol/L) group. F-actin in the HTM cells was detected by FITC-phallodin and observed under a fluorescence microscope. The expression of β-catenin was determined by immunofluorescence and western-blot. Statistical analysis was performed using SPSS13.0 software. The difference of β-catenin expression among groups was analyzed through variance analysis and, further by q test. Results The cultured HTM cells were identified by immunohistochemistry. A reorganization of actin cytoskeletal and a formation of cross linked actin networks (CLANs) were seen in the HTM cells treated with DEX, which were partially reversed by the treatment with DEX plus travoprost. An increase of the expression of β-catenin was discovered in the HTM cells treated with DEX, which was also partially reversed by the treatment with DEX plus travoprost. The amount of β-catenin protein in untreated control group, DEX group, DEX plus travoprost group and travoprost group were 0. 84 ± 0. 03,1.65 ± 0. 05, 1.21 ± 0. 05, and 0. 65 ±0. 04, respectively. Expression of β-catenin was significantly ( F = 143.07, P ＜ 0. 05 ) different when compared untreated control group with DEX group ( q = 15. 32 ,P ＜0. 05 ), untreated control group with DEX plus travoprost group (q = 11.40,P＜0. 05), DEX group with DEX plus travoprost group (q =9. 38,P ＜ 0. 05 ), DEX group with travoprost group ( q = 16. 55, P ＜ 0. 05 ), and DEX plus travoprost group with travoprost group (q = 14. 31 ,P ＜ 0. 05 ). No difference was found in untreated control group and travoprost group(q = 2. 84, P ＞ 0. 05 ). Conclusions Our results suggest that reversion of the changes of actin organization and β-catenin by travoparost in the HTM cells treated with DEX may partially elucidate the mechanism of action of increasing outflow by which travoprost reduces intraocular pressure.     

曲伏前列素对地塞米松诱导的人眼小梁细胞骨架及β黏蛋白的影响

目的 研究曲伏前列素对地塞米松诱导的人眼小梁细胞肌动蛋白细胞骨架及β黏蛋白表达的影响.方法 对照实验研究.人眼小梁细胞体外培养、传代.实验分为4组,第1组为空白对照组,第2组为地塞米松(1 ×10-6mol/L)处理组,第3组为地塞米松(1×10-6mol/L)+曲伏前列素(1×10-6mol/L)处理组,第4组为曲伏前列素处理组.培养的人眼小梁细胞于相差显微镜下观察其形态并拍照,于荧光显微镜下观察细胞骨架结构及β黏蛋白变化,用免疫印迹法半定量检测β黏蛋白的表达水平.组间β黏蛋白表达水平比较采用方差分析,进一步两两比较采用q检验.结果 培养的人眼小梁细胞经地塞米松诱导后微丝重组杂乱,形成交叉连接肌动蛋白网结构,β黏蛋白染色明显加强.地塞米松联合曲伏前列素处理组可部分逆转地塞米松诱导的微丝重组和交叉连接肌动蛋白网结构的形成,使β黏蛋白染色明显减弱.空白组、地塞米松组、地塞米松联合曲伏前列素组及曲伏前列素组β黏蛋白表达相对灰度值分别为0.84±0.03、1.65±0.05、1.21±0.05及0.65±0.04,组间β黏蛋白表达差异有统计学意义(F=143.07,P＜0.05).进一步两两比较,除空白组与曲伏前列素组β黏蛋白表达差异无统计学意义(q=2.84,P＞0.05)外,空白组与地塞米松组(q=15.32)、空白组与地塞米松联合曲伏前列素组(q=11.40)、地塞米松组与地塞米松联合曲伏前列素组(q=9.38)、地塞米松组与曲伏前列素组(q=16.55)、地塞米松联合曲伏前列素组与曲伏前列素组(q=14.31)比较,β黏蛋白表达差异均有统计学意义(P＜0.05).结论 曲伏前列素可以部分逆转由地塞米松诱导的人眼小梁细胞骨架及β黏蛋白的改变,这可能是曲伏前列素通过调节小梁网房水流出途径并降低眼压的机制之一.

Abstract：

Objective To investigate the effect of travoprost on changes of actin cytoskeletal and β-catenin protein in the cultured human trabecular meshwork (HTM) cells treated with dexamethasone (DEX). Methods It was a control experiment study. The HTM cells were cultured in vitro and divided into control group, DEX (1 × 10-6mol/L) group, travoprost (1 × 10-6mol/L) group, and DEX (1 ×10-6mol/L) plus travoprost (1 × 10-6mol/L) group. F-actin in the HTM cells was detected by FITC-phallodin and observed under a fluorescence microscope. The expression of β-catenin was determined by immunofluorescence and western-blot. Statistical analysis was performed using SPSS13.0 software. The difference of β-catenin expression among groups was analyzed through variance analysis and, further by q test. Results The cultured HTM cells were identified by immunohistochemistry. A reorganization of actin cytoskeletal and a formation of cross linked actin networks (CLANs) were seen in the HTM cells treated with DEX, which were partially reversed by the treatment with DEX plus travoprost. An increase of the expression of β-catenin was discovered in the HTM cells treated with DEX, which was also partially reversed by the treatment with DEX plus travoprost. The amount of β-catenin protein in untreated control group, DEX group, DEX plus travoprost group and travoprost group were 0. 84 ± 0. 03,1.65 ± 0. 05, 1.21 ± 0. 05, and 0. 65 ±0. 04, respectively. Expression of β-catenin was significantly ( F = 143.07, P ＜ 0. 05 ) different when compared untreated control group with DEX group ( q = 15. 32 ,P ＜0. 05 ), untreated control group with DEX plus travoprost group (q = 11.40,P＜0. 05), DEX group with DEX plus travoprost group (q =9. 38,P ＜ 0. 05 ), DEX group with travoprost group ( q = 16. 55, P ＜ 0. 05 ), and DEX plus travoprost group with travoprost group (q = 14. 31 ,P ＜ 0. 05 ). No difference was found in untreated control group and travoprost group(q = 2. 84, P ＞ 0. 05 ). Conclusions Our results suggest that reversion of the changes of actin organization and β-catenin by travoparost in the HTM cells treated with DEX may partially elucidate the mechanism of action of increasing outflow by which travoprost reduces intraocular pressure.     

Effects of dexamethasone and HA1077 on actin cytoskeleton and β-catenin in cultured human trabecular meshwork cells

AIM: To investigate the effects of dexamethasone (DEX) and 1-(5-isoquinolinesulfonyl)-homopiperazine (HA1077) on actin cytoskeleton and β-catenin in cultured human trabecular meshwork (HTM) cells. METHODS: The HTM cells were separated from human eyeball and cultured in vitro. They were divided into control group, DEX (1×10-6 mol/L) group, HA1077 (3×10-5 mol/L) group, and DEX (1×10-6 mol/L) and HA1077 (3×10-5 mol/L) group. Actin cytoskeleton and β-catenin in HTM cells of the four groups were examined by immunofluorescence and Western blot analyses. RESULTS: In DEX group, there were reorganization of actin cytoskeleton and formation of cross linked actin networks (CLANs), which were partially reversed in DEX and HA1077 group. DEX treatment also induced an increased expression of β-catenin, which was obviously reduced in DEX and HA1077 group. Meanwhile, the cultured HTM cells in HA1077 group had lower expression of β-catenin than that in the control group. CONCLUSION: Our results show that HA1077 can reverse the changes of actin organization and expression of β-catenin induced by DEX in cultured HTM cells, suggesting that HA1077 may play an important role in increasing outflow and reducing intraocular pressure.     

Human β-NGF gene transferred to cat corneal endothelial cells

AIM: To transfect the cat corneal endothelial cells (CECs) with recombinant human β-nerve growth factor gene adeno-associated virus (AAV-β-NGF) and to observe the effect of the expressed β-NGF protein on the proliferation activity of cat CECs. METHODS: The endothelium of cat cornea was torn under the microscope and rapidly cultivated in Dulbecco’s modified Eagle''s medium (DMEM) to form single layer CECs and the passage 2 endothelial cells were used in this experiment. The recombinant human AAV-β-NGF was constructed. The recombinant human AAV-β-NGF was transferred into cat CECs directly. Three groups were as following: normal CEC control group, CEC-AAV control group and recombinant CEC-AAV-β-NGF group. Forty-eight hours after transfection, the total RNA was extracted from the CEC by Trizol. The expression of the β-NGF target gene detected by fluorescence quantitative polymerase chain reaction; proliferation activity of the transfected CEC detected at 48h by MTT assay; the percentage of G1 cells among CECs after transfect was detected by flow cytometry method (FCM); cell morphology was observed under inverted phase contrast microscope. RESULTS: The torn endothelium culture technique rapidly cultivated single layer cat corneal endothelial cells. The self-designed primers for the target gene and reference gene were efficient and special confirmed through electrophoresis analysis and DNA sequencing. Forty-eight hours after transfect, the human β-NGF gene mRNA detected by fluorescence quantitative polymerase chain reaction showed that there was no significant difference between normal CEC control group and CEC-AAV control group (P>0.05); there was significant difference between two control groups and recombinant CEC-AAV-β-NGF group (P<0.05). MTT assay showed that transfect of recombinant AAV-β-NGF promoted the proliferation activity of cat CEC, while there was no significant difference between normal CEC control group and CEC-AAV control group (P>0.05). FCM result showed that the percentage of G1cells in CEC-AAV-NGF group was 76.8% while that in normal CEC control group and CEC-AAV control group was 46.6% and 49.8%. CONCLUSION: Recombinant AAV-β-NGF promotes proliferation in cat CECs by expressing bioactive β-NGF protein in high efficiency and suggests that its modulation can be used to treat vision loss secondary to corneal endothelial dysfunction.     

Biomechanics of sclera crosslinked using genipin in rabbit

AIM: To strengthen the biomechanics of collagen by crosslinking rabbit scleral collagen with genipin to develop a new therapy for preventing myopic progression. METHODS: Ten New Zealand rabbits were treated with 0.5 mmol/L genipin injected into the sub-Tenon’s capsule in the right eyes. Untreated contralateral eyes served as the control. The treated area was cut into scleral strips measuring 4.0 mm×10.0 mm for stress-strain measurements (n=5). The remaining five treated eyes were prepared for histological examination. RESULTS: Compared to the untreated scleral strips, the genipin-crosslinked scleral strips showed that the ultimate stress and Young’s modulus at 10% strain were increased by the amplitude of 130% and 303% respectively, ultimate strain was decreased by 24%. There had no (-smooth muscle actin ((-SMA) positive cells in control and treated sclera. Histologically, there was no sign of apoptosis in the sclera, choroid, and retina; and no side effects were found in the peripheral cornea and optic nerve adjacent to the treatment area. CONCLUSION: Genipin induced crosslinking of collagen can increase its biomechanical behavior by direct strengthening of the extracellular matrix in rabbit sclera, with no (-SMA expression seen in the myofibroblasts. As there is no evidence of cytotoxicity in the scleral, choroidal, and retinal cells, genipin is likely a promising agent to strengthen the weakened sclera to prevent myopic progression.     

褪黑素对体外培养的人视网膜色素上皮细胞氧化损伤的保护作用

Objective To investigate the protective effects of melatonin on the retinal pigment epithelium (RPE) against oxidative damage induced by hydrogen dioxide (H2O2) and its mechanism. Methods The RPE cells were seeded and divided into normol control group, oxidative damage group and the treatment group (treated with melatonin at the concentration of 1×10.7 mol/L,1×10-6 mol/L, 1×10-5 mol/L and 1×10-4 mol/L). The model of oxidative damage on the RPE cells was established by culturing the RPE cells with H2O2 at the concentration of 600 μmol/L for 1 hour in vitro. The cell viability of RPE cells was detected by the methyl thiazolyl tetrazolium (MTT) method. The degree of oxidative damage was evaluated by detecting the superoxide dismutase (SOD) and maleic dialdehyde (MDA). Apoptosis was detected qualitatively using the DNA Ladders electrophoretic mothed, and quantitatively using the Annexin V-FITC/PI double staining flow cytometry. Results Compared with normal control group, the oxidative damage group had low cell viability, low SOD and high MDA contents, and high apoptosis rate(t=2.25,39.50,68.42;P<0.05). Compared with oxidative damage group, the treatment group had high cell viability, high SOD and low M DA contents, and low apoptosis rate (P<0.05). Conclusions Melatonin has a protective effect on the RPE against oxidative damage induced by H2O2. The mechanism may involve in reinforcing the cell viability, strengthening the activity of antioxidase, and reducing the apoptosis.     

褪黑素对体外培养的人视网膜色素上皮细胞氧化损伤的保护作用

Objective To investigate the protective effects of melatonin on the retinal pigment epithelium (RPE) against oxidative damage induced by hydrogen dioxide (H2O2) and its mechanism. Methods The RPE cells were seeded and divided into normol control group, oxidative damage group and the treatment group (treated with melatonin at the concentration of 1×10.7 mol/L,1×10-6 mol/L, 1×10-5 mol/L and 1×10-4 mol/L). The model of oxidative damage on the RPE cells was established by culturing the RPE cells with H2O2 at the concentration of 600 μmol/L for 1 hour in vitro. The cell viability of RPE cells was detected by the methyl thiazolyl tetrazolium (MTT) method. The degree of oxidative damage was evaluated by detecting the superoxide dismutase (SOD) and maleic dialdehyde (MDA). Apoptosis was detected qualitatively using the DNA Ladders electrophoretic mothed, and quantitatively using the Annexin V-FITC/PI double staining flow cytometry. Results Compared with normal control group, the oxidative damage group had low cell viability, low SOD and high MDA contents, and high apoptosis rate(t=2.25,39.50,68.42;P<0.05). Compared with oxidative damage group, the treatment group had high cell viability, high SOD and low M DA contents, and low apoptosis rate (P<0.05). Conclusions Melatonin has a protective effect on the RPE against oxidative damage induced by H2O2. The mechanism may involve in reinforcing the cell viability, strengthening the activity of antioxidase, and reducing the apoptosis.     

褪黑素对体外培养的人视网膜色素上皮细胞氧化损伤的保护作用

Objective To investigate the protective effects of melatonin on the retinal pigment epithelium (RPE) against oxidative damage induced by hydrogen dioxide (H2O2) and its mechanism. Methods The RPE cells were seeded and divided into normol control group, oxidative damage group and the treatment group (treated with melatonin at the concentration of 1×10.7 mol/L,1×10-6 mol/L, 1×10-5 mol/L and 1×10-4 mol/L). The model of oxidative damage on the RPE cells was established by culturing the RPE cells with H2O2 at the concentration of 600 μmol/L for 1 hour in vitro. The cell viability of RPE cells was detected by the methyl thiazolyl tetrazolium (MTT) method. The degree of oxidative damage was evaluated by detecting the superoxide dismutase (SOD) and maleic dialdehyde (MDA). Apoptosis was detected qualitatively using the DNA Ladders electrophoretic mothed, and quantitatively using the Annexin V-FITC/PI double staining flow cytometry. Results Compared with normal control group, the oxidative damage group had low cell viability, low SOD and high MDA contents, and high apoptosis rate(t=2.25,39.50,68.42;P<0.05). Compared with oxidative damage group, the treatment group had high cell viability, high SOD and low M DA contents, and low apoptosis rate (P<0.05). Conclusions Melatonin has a protective effect on the RPE against oxidative damage induced by H2O2. The mechanism may involve in reinforcing the cell viability, strengthening the activity of antioxidase, and reducing the apoptosis.     

褪黑素对体外培养的人视网膜色素上皮细胞氧化损伤的保护作用

Objective To investigate the protective effects of melatonin on the retinal pigment epithelium (RPE) against oxidative damage induced by hydrogen dioxide (H2O2) and its mechanism. Methods The RPE cells were seeded and divided into normol control group, oxidative damage group and the treatment group (treated with melatonin at the concentration of 1×10.7 mol/L,1×10-6 mol/L, 1×10-5 mol/L and 1×10-4 mol/L). The model of oxidative damage on the RPE cells was established by culturing the RPE cells with H2O2 at the concentration of 600 μmol/L for 1 hour in vitro. The cell viability of RPE cells was detected by the methyl thiazolyl tetrazolium (MTT) method. The degree of oxidative damage was evaluated by detecting the superoxide dismutase (SOD) and maleic dialdehyde (MDA). Apoptosis was detected qualitatively using the DNA Ladders electrophoretic mothed, and quantitatively using the Annexin V-FITC/PI double staining flow cytometry. Results Compared with normal control group, the oxidative damage group had low cell viability, low SOD and high MDA contents, and high apoptosis rate(t=2.25,39.50,68.42;P<0.05). Compared with oxidative damage group, the treatment group had high cell viability, high SOD and low M DA contents, and low apoptosis rate (P<0.05). Conclusions Melatonin has a protective effect on the RPE against oxidative damage induced by H2O2. The mechanism may involve in reinforcing the cell viability, strengthening the activity of antioxidase, and reducing the apoptosis.     

褪黑素对体外培养的人视网膜色素上皮细胞氧化损伤的保护作用

Objective To investigate the protective effects of melatonin on the retinal pigment epithelium (RPE) against oxidative damage induced by hydrogen dioxide (H2O2) and its mechanism. Methods The RPE cells were seeded and divided into normol control group, oxidative damage group and the treatment group (treated with melatonin at the concentration of 1×10.7 mol/L,1×10-6 mol/L, 1×10-5 mol/L and 1×10-4 mol/L). The model of oxidative damage on the RPE cells was established by culturing the RPE cells with H2O2 at the concentration of 600 μmol/L for 1 hour in vitro. The cell viability of RPE cells was detected by the methyl thiazolyl tetrazolium (MTT) method. The degree of oxidative damage was evaluated by detecting the superoxide dismutase (SOD) and maleic dialdehyde (MDA). Apoptosis was detected qualitatively using the DNA Ladders electrophoretic mothed, and quantitatively using the Annexin V-FITC/PI double staining flow cytometry. Results Compared with normal control group, the oxidative damage group had low cell viability, low SOD and high MDA contents, and high apoptosis rate(t=2.25,39.50,68.42;P<0.05). Compared with oxidative damage group, the treatment group had high cell viability, high SOD and low M DA contents, and low apoptosis rate (P<0.05). Conclusions Melatonin has a protective effect on the RPE against oxidative damage induced by H2O2. The mechanism may involve in reinforcing the cell viability, strengthening the activity of antioxidase, and reducing the apoptosis.     

褪黑素对体外培养的人视网膜色素上皮细胞氧化损伤的保护作用

Objective To investigate the protective effects of melatonin on the retinal pigment epithelium (RPE) against oxidative damage induced by hydrogen dioxide (H2O2) and its mechanism. Methods The RPE cells were seeded and divided into normol control group, oxidative damage group and the treatment group (treated with melatonin at the concentration of 1×10.7 mol/L,1×10-6 mol/L, 1×10-5 mol/L and 1×10-4 mol/L). The model of oxidative damage on the RPE cells was established by culturing the RPE cells with H2O2 at the concentration of 600 μmol/L for 1 hour in vitro. The cell viability of RPE cells was detected by the methyl thiazolyl tetrazolium (MTT) method. The degree of oxidative damage was evaluated by detecting the superoxide dismutase (SOD) and maleic dialdehyde (MDA). Apoptosis was detected qualitatively using the DNA Ladders electrophoretic mothed, and quantitatively using the Annexin V-FITC/PI double staining flow cytometry. Results Compared with normal control group, the oxidative damage group had low cell viability, low SOD and high MDA contents, and high apoptosis rate(t=2.25,39.50,68.42;P<0.05). Compared with oxidative damage group, the treatment group had high cell viability, high SOD and low M DA contents, and low apoptosis rate (P<0.05). Conclusions Melatonin has a protective effect on the RPE against oxidative damage induced by H2O2. The mechanism may involve in reinforcing the cell viability, strengthening the activity of antioxidase, and reducing the apoptosis.     

血管能抑素基因转移抑制视网膜新生血管的实验研究

Objective To observe the inhibitory effects of gene transfer of canstatin on retinal neovascularization in mice. Methods Fifty-six 7-day-old C57BL/6J mice were randomly divided into control group, oxygen-induced retinopathy (OIR) group, empty vector group and treated group, 14 mices in each group. Except for the control group, the mice in the other groups were exposed to (75±2)% oxygen for 5 days and then back to the normal air to establish the model of OIR. On postnatal 12 day, the treated group was received intravitreal injection of canstatin pCMV-HA, while the empty vector group was received the same volume of empty plasmid. The changes of retinal vessels were observed by Evans blue angiography on postnatal 17 day. With parafin section which stained by hematoxylin and eosin, then the number of endotheliocyte nuclei breaking throuhgh the internal limiting membrane(ILM) was observed and counted by optical microscope. Results Retinal blood vessels distributed regularly in treated group compared with OIR group and empty vector group. The differences of the number of endotheliocyte nuclei breaking throuhgh ILM in treated group was significant compared with the other two groups(F= 39. 006, P< 0. 001).Conclusion The canstatin pCMV-HA can effectively inhibit the retinal neovascularization in OIR.     

血管能抑素基因转移抑制视网膜新生血管的实验研究

Objective To observe the inhibitory effects of gene transfer of canstatin on retinal neovascularization in mice. Methods Fifty-six 7-day-old C57BL/6J mice were randomly divided into control group, oxygen-induced retinopathy (OIR) group, empty vector group and treated group, 14 mices in each group. Except for the control group, the mice in the other groups were exposed to (75±2)% oxygen for 5 days and then back to the normal air to establish the model of OIR. On postnatal 12 day, the treated group was received intravitreal injection of canstatin pCMV-HA, while the empty vector group was received the same volume of empty plasmid. The changes of retinal vessels were observed by Evans blue angiography on postnatal 17 day. With parafin section which stained by hematoxylin and eosin, then the number of endotheliocyte nuclei breaking throuhgh the internal limiting membrane(ILM) was observed and counted by optical microscope. Results Retinal blood vessels distributed regularly in treated group compared with OIR group and empty vector group. The differences of the number of endotheliocyte nuclei breaking throuhgh ILM in treated group was significant compared with the other two groups(F= 39. 006, P< 0. 001).Conclusion The canstatin pCMV-HA can effectively inhibit the retinal neovascularization in OIR.     

褪黑素对体外培养的人视网膜色素上皮细胞氧化损伤的保护作用

Objective To investigate the protective effects of melatonin on the retinal pigment epithelium (RPE) against oxidative damage induced by hydrogen dioxide (H2O2) and its mechanism. Methods The RPE cells were seeded and divided into normol control group, oxidative damage group and the treatment group (treated with melatonin at the concentration of 1×10.7 mol/L,1×10-6 mol/L, 1×10-5 mol/L and 1×10-4 mol/L). The model of oxidative damage on the RPE cells was established by culturing the RPE cells with H2O2 at the concentration of 600 μmol/L for 1 hour in vitro. The cell viability of RPE cells was detected by the methyl thiazolyl tetrazolium (MTT) method. The degree of oxidative damage was evaluated by detecting the superoxide dismutase (SOD) and maleic dialdehyde (MDA). Apoptosis was detected qualitatively using the DNA Ladders electrophoretic mothed, and quantitatively using the Annexin V-FITC/PI double staining flow cytometry. Results Compared with normal control group, the oxidative damage group had low cell viability, low SOD and high MDA contents, and high apoptosis rate(t=2.25,39.50,68.42;P<0.05). Compared with oxidative damage group, the treatment group had high cell viability, high SOD and low M DA contents, and low apoptosis rate (P<0.05). Conclusions Melatonin has a protective effect on the RPE against oxidative damage induced by H2O2. The mechanism may involve in reinforcing the cell viability, strengthening the activity of antioxidase, and reducing the apoptosis.     

褪黑素对体外培养的人视网膜色素上皮细胞氧化损伤的保护作用

Objective To investigate the protective effects of melatonin on the retinal pigment epithelium (RPE) against oxidative damage induced by hydrogen dioxide (H2O2) and its mechanism. Methods The RPE cells were seeded and divided into normol control group, oxidative damage group and the treatment group (treated with melatonin at the concentration of 1×10.7 mol/L,1×10-6 mol/L, 1×10-5 mol/L and 1×10-4 mol/L). The model of oxidative damage on the RPE cells was established by culturing the RPE cells with H2O2 at the concentration of 600 μmol/L for 1 hour in vitro. The cell viability of RPE cells was detected by the methyl thiazolyl tetrazolium (MTT) method. The degree of oxidative damage was evaluated by detecting the superoxide dismutase (SOD) and maleic dialdehyde (MDA). Apoptosis was detected qualitatively using the DNA Ladders electrophoretic mothed, and quantitatively using the Annexin V-FITC/PI double staining flow cytometry. Results Compared with normal control group, the oxidative damage group had low cell viability, low SOD and high MDA contents, and high apoptosis rate(t=2.25,39.50,68.42;P<0.05). Compared with oxidative damage group, the treatment group had high cell viability, high SOD and low M DA contents, and low apoptosis rate (P<0.05). Conclusions Melatonin has a protective effect on the RPE against oxidative damage induced by H2O2. The mechanism may involve in reinforcing the cell viability, strengthening the activity of antioxidase, and reducing the apoptosis.     

褪黑素对体外培养的人视网膜色素上皮细胞氧化损伤的保护作用

Objective To investigate the protective effects of melatonin on the retinal pigment epithelium (RPE) against oxidative damage induced by hydrogen dioxide (H2O2) and its mechanism. Methods The RPE cells were seeded and divided into normol control group, oxidative damage group and the treatment group (treated with melatonin at the concentration of 1×10.7 mol/L,1×10-6 mol/L, 1×10-5 mol/L and 1×10-4 mol/L). The model of oxidative damage on the RPE cells was established by culturing the RPE cells with H2O2 at the concentration of 600 μmol/L for 1 hour in vitro. The cell viability of RPE cells was detected by the methyl thiazolyl tetrazolium (MTT) method. The degree of oxidative damage was evaluated by detecting the superoxide dismutase (SOD) and maleic dialdehyde (MDA). Apoptosis was detected qualitatively using the DNA Ladders electrophoretic mothed, and quantitatively using the Annexin V-FITC/PI double staining flow cytometry. Results Compared with normal control group, the oxidative damage group had low cell viability, low SOD and high MDA contents, and high apoptosis rate(t=2.25,39.50,68.42;P<0.05). Compared with oxidative damage group, the treatment group had high cell viability, high SOD and low M DA contents, and low apoptosis rate (P<0.05). Conclusions Melatonin has a protective effect on the RPE against oxidative damage induced by H2O2. The mechanism may involve in reinforcing the cell viability, strengthening the activity of antioxidase, and reducing the apoptosis.     

褪黑素对体外培养的人视网膜色素上皮细胞氧化损伤的保护作用

Objective To investigate the protective effects of melatonin on the retinal pigment epithelium (RPE) against oxidative damage induced by hydrogen dioxide (H2O2) and its mechanism. Methods The RPE cells were seeded and divided into normol control group, oxidative damage group and the treatment group (treated with melatonin at the concentration of 1×10.7 mol/L,1×10-6 mol/L, 1×10-5 mol/L and 1×10-4 mol/L). The model of oxidative damage on the RPE cells was established by culturing the RPE cells with H2O2 at the concentration of 600 μmol/L for 1 hour in vitro. The cell viability of RPE cells was detected by the methyl thiazolyl tetrazolium (MTT) method. The degree of oxidative damage was evaluated by detecting the superoxide dismutase (SOD) and maleic dialdehyde (MDA). Apoptosis was detected qualitatively using the DNA Ladders electrophoretic mothed, and quantitatively using the Annexin V-FITC/PI double staining flow cytometry. Results Compared with normal control group, the oxidative damage group had low cell viability, low SOD and high MDA contents, and high apoptosis rate(t=2.25,39.50,68.42;P<0.05). Compared with oxidative damage group, the treatment group had high cell viability, high SOD and low M DA contents, and low apoptosis rate (P<0.05). Conclusions Melatonin has a protective effect on the RPE against oxidative damage induced by H2O2. The mechanism may involve in reinforcing the cell viability, strengthening the activity of antioxidase, and reducing the apoptosis.     

Autophagy: a new mechanism for regulating VEGF and PEDF expression in retinal pigment epithelium cells

AIM: To investigate the regulation of vascular endothelial growth factors (VEGF) and pigment epithelium-derived factor (PEDF) expression by autophagy in retinal pigment epithelium (RPE) cells on exposure to hypoxia. METHODS: ARPE-19, an RPE cell line, was treated as following: the control group was kept in a normoxic incubator; the hypoxia group was incubated in a hypoxic incubator with 1% O2/5% CO2/94% N2 for 24h; the hypoxia + 3-methyladenine (3-MA) group was pretreated with 10 mmol/L 3-MA for 1h and then in the hypoxic incubator for 24h; and the hypoxia + chloroquine (CQ) group was pretreated with 50 μmol/L CQ for 1h and then in the hypoxic incubator for 24h. The morphology and ultrastructure of the cells was observed by an inverted microscope or a transmission electronic microscope (TEM). Western blot was performed to assay the expression of autophagy-associated markers, including microtubule associated protein 1 light chain 3 B (LC3B), Beclin-1, Atg5 and p62. The concentration of VEGF and PEDF in the culture supernatant was determined by ELISA, and the ratio of VEGF/PEDF was calculated. RESULTS: There were no obvious differences in cell morphology among different groups and autolysosomes could be observed in the cytoplasm in all groups. Compared to the control cells, the LC3B-II/I ratio and levels of Beclin-1 and Atg5 were significantly increased and p62 level was significantly decreased in the hypoxia group. With the increase of VEGF and decrease of PEDF concentration, the VEGF/PEDF ratio was significantly increased in the hypoxia group compared to the control cells. The LC3B-II/I ratio was significantly reduced by 3-MA treatment and increased by CQ treatment. The expressions of Beclin-1 and Atg5 were significantly reduced by 3-MA or CQ treatment, while expression of p62 was increased in the 3-MA or CQ treated cells. The concentration of VEGF was significantly decreased and PEDF increased, thereby the VEGF/PEDF ratio was decreased in the hypoxia + 3-MA group and hypoxia + CQ group compared with that in the hypoxia group. CONCLUSION: Hypoxia leads to elevated autophagy in RPE cells, and expression of VEGF and PEDF might be regulated by autophagy on exposure to hypoxia to further participate in regulating the formation of retinal neovascularization.     

Modulation of TGFβ2 and dopamine by PKC in retinal Müller cells of guinea pig myopic eye

AIM: To investigate the effect of protein kinase C (PKC) on transforming growth factor-β2 (TGFβ2) and dopamine in retinal Müller cells of guinea pig myopic eye. METHODS: Myopia was induced by translucent goggles in guinea pig, whose retinal Müller cells were cultured using the enzyme-digesting method. Retinal Müller cells were divided into 5 groups: normal control, myopia, myopia plus GF109203X, myopia plus PMA, myopia plus DMSO. PKC activities were detected by the non-radioactive methods. TGFβ2 and tyrosine hydroxylase (TH) proteins were analyzed by Western Blotting in retinal Müller cells. Dopamine was determined by the high-performance liquid chromatography-electrochemical detection in suspensions. RESULTS: After 14 days deprived, the occluded eyes became myopic with ocular axle elongating. Müller cells of guinea pigs were obtained using enzyme digestion. Compared with normal control group, the increase in PKC activity and the up-regulation in TGFβ2 expression were found in retinal Müller cells of myopic eyes, with the decrease of TH and dopamine content (P<0.05). After PKC activated by PMA, TGFβ2 and TH content were up-regulated with the increase of dopamine content (P<0.05). While the PKC activities was inhibited by GF109203X, proteins of TGFβ2 and TH were down-regulated in the myopic eyes, with the decrease of dopamine content (P<0.05). CONCLUSION: TGFβ2 and dopamine are modulated by PKC in Müller cells of the myopic eyes in guinea pig.