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AIM: To investigate the preventive effect and optimal drug dose of lipoic acid-niacin(N2L)against blue light-induced retinal damage in SD rats, and to explore its possible protective mechanism.METHODS: A total of 36 specific pathogen free-grade male SD rats of 150-200 g were selected and randomly divided into normal control group, blue light injury group, N2L low-dose group(1.0 mg/kg), N2L medium-dose group(2.5 mg/kg), N2L high-dose group(5.0 mg/kg), and physiological saline group, with 6 rats in each group. The normal control group was reared in a 12 h dark and light cycle, and the rest of the groups received 9 h of daily light exposure, 3 h of blue light irradiation with a wavelength of 455 nm and an intensity of 3000±50 lx, and 12 h of darkness to establish the injury model, and were exposed to light exposure for 14 d. For 14 consecutive durations, a 1 mL dose of the corresponding drug was injected intraperitoneally. The rats were reared for another 5 d with a regular 12 h light-dark cycle and were examined by electroretinography. Specimens were prepared by over anesthesia, HE staining, and the thickness of the outer nuclear layer was observed under a optical microscope; superoxide dismutases(SOD)activity was detected by CheKineTM SOD Activity Assay Kit; and the retinal Caspase-3, quinone oxidoreductase 1(NQO1), glutathione S transferase(GST), Bcl-2, and Bax protein expression in rat retina were detected by Western blot.RESULTS: The amplitude of b-wave in dark-vision ERG 3.0 and 10.0(cd·s)/m2 stimulated light, b-wave in bright-vision ERG 3.0(cd·s)/m2 stimulated light, and the amplitude of the 2nd wave peak of oscillatory potential were significantly lower in blue light injury group than that in the normal control group(all P<0.01), while the amplitude was significantly higher in the N2L medium-dose group than in the blue light injury group(all P<0.05), and was not statistically different from that of the normal control group; the thickness of the retina in the blue light injury group was decreased in the ONL compared with that of the normal control group(P<0.001), while in the N2L medium dose group, it was thicker than that of the blue light injury group(P<0.001), and there was no statistically significant difference from the normal control group; SOD activity was significantly higher in the N2L medium-dose group than in the remaining 5 groups(P<0.05); the expression of Caspase-3, Bax, and NQO1 in the blue light injury group was higher than that of the normal control group(all P<0.01), and expression of Bax and Caspase-3 was significantly lower in the N2L medium-dose group compared with the blue light injury group(all P<0.001), whereas GST, NQO1 and Bcl-2 were significantly increased(all P<0.01).CONCLUSION:A concentration of 2.5 mg/kg N2L can effectively antagonize the damaging effect of blue light on the retina of SD rats, and it is expected to be a preventive and curative drug for it.
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Objective To research the role of mitochondrial DNA mediate the cultured human retinal pigment epithelium (hRPE) cell apoptosis induced by blue light and the relationship with time.Methods Established the blue light damage model of cultured hRPE cells in vitro with light emitting diode (LED) blue light density of (4.0-±0.5)mW/cm2 adjusted by FL-1D blue light illumination meter,and the illumination time was set as 0,0.5,1,2,4,6,12 and 24 hours,then the cells were grouped according to the illumination time.Immunofluorescence were used to identify the cells;the expressions of caspase-3,cleaved caspase-3,caspase-9,cleaved caspase-9,bax and bcl-2 were detected with Western blot.Quantitative PCR was used to detect the copy number of mitochondrial DNA and PCR was used to detect mitochondrial DNA 4977bp common deletion.Results Immunofluorescence results showed that the RPE65 protein was expressed in the cytoplasm.The expressions of bax were upregulated after illumination for 1 hour,cleaved caspase-3 were upregulated after illumination for 2 hours,caspase-3,caspase-9,cleaved caspase-9 were upregulated after illumination for 4 hours,while the expression of bcl-2 was downregulated after illuminated for 2 hours,with significant differences compared to the normal control group (all at P＜0.05).The copy number of mitochondrial DNA in 0.5,1,2,4,6,12 and 24 hours groups was downregulated,with significant differences compared to the normal control group (all at P＜0.05).The expressions of 4977bp common deletion in 0.5,1,2,4,6,12 and 24 hours groups were increased,with significant differences compared with the normal control group (all at P＜0.05).Conclusions Blue light can cause cell apoptosis,especially mitochondrial apoptosis,in hRPE probably motivated by mitochondrial DNA damage.
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Objective To investigate the effects of artesunate (Art) on cell proliferation and apoptosis of human Tenon's capsule fibroblasts (HTFs),and discuss the countermeasures of bleb scarfing in glaucoma.Methods In vitro,HTFs were cultivated and applicated by different concentrations (50 μg · mL-1,100 μg · mL-1,150 μg ·mL-1,200 μg · mL-1) of Art for 48 hours.The effect of Art on cell proliferation was assessed by MTT method.The rate of apoptosis induced by Art was determined by flow cytometry.Western Blot was performed to detect the relative expression levels of Bax and Bcl-2 after Art was treated.Results After treated with Art for 48 hours,compared with blank control group,Art (50 μg · mL-1,100 μg · mL-1,150 μg · mL-1,200 μg · mL-1) group exhibited notable anti-proliferative effect on HTFs with concentration-dependence (all P ＜ 0.05).The results of flow cytometry showed that the apoptosis rates (8.80％ ±0.88％,11.60％ ±0.56％,16.30％ ±1.03％,23.40％ ±1.62％) of HTFs were significantly enhanced with the increase of Art concentration (all P ＜ 0.05).The relative expression levels of Bax were obviously high with the increase of Art concentration,while Bcl-2 levels were significantly low with the increase of Art concentration (all P ＜ 0.05).Conclusion Art can inhibit the proliferation and induce cell apoptosis of HTFs possibly by enhancing the expression of Bax and reducing the expression of Bcl2.Art may be a potential drug in preventing fibrous scar formation after glaucoma filtration surgery.
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Background Light-induced retinal damage results in the damage of retinl pigment epithelial (RPE) cells and therefore affects the pathogenesis and development of age-related macular degeneration (AMD).Studies showed that tissue factor (TF) is overexpressed in oxidative damaged RPE cells and the choroidal neovascularization (CNV) of AMD,speculating that the suppression of TF can prevent the damage of RPE cells and inhibit CNV.Objective This study was conducted to observe the protective effects of TF targeting peptide (TFTP),a new drug of autologous synthesis,on human RPE-cells induced by blue light.Methods Human RPE cells were isolated from donor eye and cultured.Cultured cells were divided into blank control group,model group and TFTP treated group.Light-induced RPE cell damage model was established by exposuring the cells in the blue light of (4.0±-0.5) mW/cm2 for 12 hours in the model group,and different concentrations (10,100,150,200,300 μmol/L) of TF-TP were added into the medium to pretreat the cells for 24 hours and then exposed the cells to the blue light for 12 hours in the TF-TP groups.The cell viability was determined by CCK-8 assay.The morphology and ultrastructure in the cells were observed under the inverted microscope and transmission electron microscope.The apoptosis of the cells was assayed by Hoechst staining.The expressions of TF and apoptosis-related protein bax,bcl-2 in the cells were determined by Western blot.Results CCK-8 assay showed that there was no significant difference in the cell viability among blank control group and different concentrations TF-TP groups (F=2.15,P =0.11).The cell survival rate of blank control group,model group and 150 μmol/L TF-TP group was (100.0±0.00) ％,(43.79±6.55) ％ and (63.45±3.57) ％,and the survial rate was increased in the 150 μmol/L TF-TP group compared with the model group (P =0.00),and 150 μmol/L was detemined as a optimal concentration of TF-TP.A lot of shrinkage,deformation,suspension cells were exhibited under the optical microscope,and decrease of microvilli structure,rupture of mitochondrial cristae and vacuolar degeneration of the cells were found in the model group,and the damage of the cells were evidently lightened in the 150 μ mol/L TF-TP group.The apoptosis rate of the cells were (0.98 ±0.19)％,(9.98 ±0.82) ％ and (5.73 ±0.88) ％ in the blank group,model group and 150 μmol/L TF-TP group,respectively,with a significant difference among the groups (F =206.18,P =0.00),and the apoptosis rate of the cells in the 150 μmol/L TF-TP group was significantly lower than that in the model group (P＜0.05).Compared with the blank control group,the relative expression of bax and TF was obviously increased and that of bcl-2 was decreased in the model group;while the expression of bax and TF was lower,and that of bcl-2 was higher in the 150 μmol/L TF-TP group compared with the model group (all at P ＜ 0.05).Conclusions Pretreation of TF-TP can lessen cell apoptosis and increase cell survival rate and therefore plays a protective role to blue light-induced human RPE cells possibly by inhibiting bax/bcl-2 apoptotic pathways mediated by TF.
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Background Researches showed that mitochondria and oxidative stress play a crucial role in retinal photochemical injury,but the relationship between the damage of human retinal pigment epithelium (RPE) cell-induced by blue light and light-irradiated time is less studied.Objective The aim of this study was to research the possible mechanism of RPE oxidative damage induced by blue light in vitro.Methods Human RPE cells were isolated from healthy donors and cultured.The cells were divided into the normal control group and the light exposure group.The cells of light exposure group were irradiated using the blue light of (4.0±0.5) mW/cm2 for 0.5,1,2,3,4,5,6,12 and 24 hours,respectively,and the cells of the normal control group were cultured in dark environment.Cellular viability was detected by MTT method,and the ultrastructure change of subcellular organelles in RPE cells was examined under the transmission electron microscope (TEM).The content of reactive oxygen species (ROS) was assayed by flow cytometry for the assessment of oxidative stress reaction.The relative expressions of nicotinamide adenine dinucleotide phosphate (NADPH) mRNA and cyclooxygenase 1 (COX1) mRNA in the cells were detected by real-time fluorescence quantitative PCR to evaluate the mitochondria function.Results The percentages of cellular viability were (100.00±20.00) ％,(95.73±0.89) ％,(94.67±2.56) ％,(84.23±0.16) ％,(78.57±3.09)％,(75.43±2.18)％,(66.13±1.42)％,(53.43±1.91)％ and (47.97±1.36)％ in the normal control group and light exposure for 1-hour,2-hour,3-hour,4-hour,5-hour,6-hour,12-hour and 24-hour groups,respectively,showing a significant difference among the groups (F =172.270,P =0.000),and the percentages of light exposure for the more than 3 hours groups were significantly lower than those of the normal control group (all at P＜ 0.05).The vacuoles-like degeneration,mitochondrial swelling,decreased microvilli were seen under the TEM.The contents of ROS in RPE cells were (14.75±2.49)％,(19.04± 1.02) ％,(22.81 ±3.20)％,(28.75±2.15)％,(33.06±0.96) ％,(40.64±2.11) ％,(48.25±2.50) ％ and (60.44±2.68) ％ in the normal control group and light exposure for 0.5-hour,1-hour,2-hour,3-hour,4-hour,5-hour,6-hour groups,and with significant increases in ROS contents in various light exposure groups compared with the normal control group (all at P＜0.05).The relative expression levels of NAPDH mRNA in the cells were gradually elevated 3 hours after light exposure with the increase of time in comparison with the normal control group (all at P＜0.05),and the relative expression levels of COX1 mRNA in the cells were higher in the light exposure for 2-hour,3-hour,4-hour and 5-hour group compared with the normal control group (all at P＜0.05),and after that the COX1 mRNA levels were gradually declined and were close to the normal level.Conclusions Blue light irradiation for more than 3 hours causes oxidative stress damage of mitochondria in RPE in vitro,and the damage was more obvious after irradiation for 5-6 hours.
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Mitochondrial DNA (mtDNA) is a genetic effect DNA molecule of double closed loop, and is crucial for cells and their functions. Mitochondria take an active part in physiological activities of retinal pigment epithelium (RPE) cells. The oxidative stress is usually occurred in RPE for its active metabolism, which can lead to mitochondria and mtDNA dam?age. Once mitochondria and mtDNA lesions have not been repaired timely, the lesions can be accumulated, which can cause dysfunctions and damaged-structures of RPE and mitochondria, and can motivate the progression of cell apoptosis. In the end it can result in some ocular related diseases such as aged-related macular degeneration (AMD). This study reviewed the functional relationship between mtDNA and RPE, and repair and detection methods of mtDNA damage.
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Objective To investigate the regulations of Bax , Bcl-2 in the protection of lipoic acid-niacin diad in acrolein-induced apoptosis in ARPE-19 cells. Methods The ARPE-19 cells were cultured in medium containing 10% fetal bovine serum , at 37 ℃ with 5% CO2. The ARPE-19 was transferred to 6-well plate after reaching to 70% confluence. After starvation for 24 h , the cells in 6-well plates were divided into three groups , including the blank control group , the acrolein treatment group with 50 μmol/L acrolein for 24 h , and the protection group with 100 μmol/L lipoic acid-niacin diad for 24 h and with the acrolein for another 24 h. The apoptotic cells were detected by flow cytometry assay , and expressions of Bcl-2 , Bax protein were detected by Western Blot assay. Results The percentages of normal healthy cells were 94.8%, 60.98%, and 91.34% in the blank control group , 50 μmol/L acrolein group and 100 μmol/L diad contained of lipoic acid and niacin group , respectively. The ratios of Bax/Bcl-2 protein expression were 0.293 9, 1.389 2, and 0.555 8 in the blank control group, 50 μmol/L acrolein group and 100 μmol/L diad contained of lipoic acid and niacin group, respectively. Conclusion The protective effect of lipoic acid-niacin diad on acrolein-induced apoptosis in ARPE-19 cell through promoting Bcl-2 expression and inhibiting Bax expression.
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<p><b>OBJECTIVE</b>To observe the influence of flap-on or flap-off Epipolis laser in situ keratomileusis (epi-LASIK) on the release of transforming growth factor-β1 (TGF-β1) in tear fluid and corneal haze formation.</p><p><b>METHODS</b>Thirty patients (60 eyes) with myopia underwent epi-LASIK surgery with epithelial flap repositioning (flap-on) in the right eyes and epithelial flap removal (flap-off) in the left eyes. The level of TGF-β1 in tears was measured preoperatively and on days 1, 3, and 7 postoperatively. Corneal haze was graded at 1, 3 and 6 months after surgery.</p><p><b>RESULTS</b>The mean preoperative spherical equivalent refraction was -4.98∓2.28 D (-2.50 to -7.25 D) in flap-on group and -5.20∓4.02 D (-1.75 to -7.00 D) in flap-off group, showing no significant difference between the two groups (P=0.80). TGF-β1 levels in the tear fluid were similar in the two groups preoperatively (P=0.11) and at 1, 3, and 7 days postoperatively (P=0.55, 0.45, 0.19, respectively). TGF-β1 levels in tears gradually decreased after the first postoperative day in both groups, but were still higher than the preoperative value till the 7th postoperative day. Corneal haze scores in the two groups were similar at 1 month (P=0.98), 3 months (P=0.52), and 6 months (P=0.72) after the operation.</p><p><b>CONCLUSION</b>Flap-on and flap-off epi-LASIK surgeries do not differ significantly in postoperative TGF-β1 levels in the tear fluid or in the postoperative haze scores. TGF-β1 may play a role in corneal wound healing.</p>
Subject(s)
Adult , Female , Humans , Male , Young Adult , Cornea , General Surgery , Epithelium, Corneal , Pathology , General Surgery , Keratomileusis, Laser In Situ , Methods , Postoperative Period , Surgical Flaps , Tears , Metabolism , Transforming Growth Factor beta1 , MetabolismABSTRACT
<p><b>OBJECTIVE</b>To evaluate the early therapeutic effect of endoscope-assisted goniosynechialysis combined with phacoemulsification and intraocular lens implantation for management of primary angle-closure glaucoma.</p><p><b>METHODS</b>Endoscope-assisted goniosynechialysis combined with phacoemulsification and intraocular lens implantation was performed in 31 patients (31 eyes) with primary angle-closure glaucoma, including 17 eyes with acute angle closure glaucoma and 14 eyes with chronic angle closure glaucoma. The patients were regularly followed up to observe the postoperative complications and changes in the intraocular pressure, visual acuity, anterior chamber depth and anterior chamber angle.</p><p><b>RESULTS</b>Hyphema occurred in 3 eyes after the operation and was absorbed gradually. The intraocular pressure decreased significantly in all the patients after the operation (P<0.05) but showed no significant differences between the acute and chronic cases (P>0.05). The intraocular pressure was over 21 mmHg in only one eye in the chronic group, and could be controlled by ocular hypotensive agents. Visual acuity improved and the anterior chamber depth increased in all the patients, showing no significant differences between the two groups (P>0.05). The anterior chamber angle all opened after the operation in 16 eyes (94.1%) in acute group, a rate significantly higher than that in the chronic group (9 eyes, 64.3%) (P<0.05). Anterior chamber angle was adhesive in 1 eye in the acute group and in 5 eyes in the chronic group. No further extension of goniosynechiae was found in these cases during the follow-up period.</p><p><b>CONCLUSIONS</b>Endoscope-assisted goniosynechialysis has such advantages as optimized visualization, accuracy and safety in the management of primary angle-closure glaucoma.</p>