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@#Retinal degenerative diseases, a type of blinding eye diseases in which retinal neuron apoptosis is the main pathological process. Neuronal cells cannot be regenerated after damage, Müller cells are important glial cells of the retina and involved in retinal development, damage, and regeneration process. In recent years, studies have proved that Müller cells are an endogenous alternative source for stimulating damaged retinal neurons and an excellent target for retinal nerve regeneration. This article reviews the related factors of Müller cells and retinal nerve regeneration, and provides a new direction for nerve regeneration research.
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@#AIM: To analyze the function and mechanism of Apelin-13 in preventing the apoptosis of retinal Müller cells induced by hypoxia.<p>METHODS: In the research, the retinal Müller cells are regarded as research subjects, and the control group, hypoxia group and experiment group are set up. The cells of control group are cultivated in normal environment. The cells of hypoxia group are cultivated in hypoxia environment. The cells of experiment group are cultivated in hypoxia environment and are treated with the Apelin-13(1μmol/L). MTT method is used to monitor the changing of the cell viability, and the crystal violet staining method is adopted to observe the cell morphology. In addition, the immunofluorescence staining method is used to test the expression of GFAP and YAP and the TUNEL staining method is used to monitor the cell apoptosis situation and the apoptosis index is calculated. The protein staining method is used to observe the changing of the expression of p-LATS1, p-YAP, LATS1 and YAP protein. <p>RESULTS:The separated and extracted Müller cells grow on the wall and show elongation, polygon and circular shapes. The cytoplasm is plentiful and the cell nucleus show circular shape. The GFAP expression of the cell is positive. The treatment with 0.1, 1, 10μmol/L Apelin-13 can obviously prevent the Müller cell viability decreasing induced by hypoxia(<i>P</i><0.05 or <i>P</i><0.01). Compared with the control group, the cell apoptosis index of hypoxia group is obviously increased(<i>P</i><0.01). However, compared with the hypoxia group, the cell apoptosis index of experiment group is obviously decreased(<i>P</i><0.01). The p-LATS1 and p-YAP protein expression of the control group and hypoxia group does not have big difference. Compared with hypoxia group, the p-LATS1 and p-YAP protein expression of experiment group is obviously decreased(<i>P</i><0.01). The YAP protein expression of cell nucleus of control group and hypoxia group does not have great difference. Compared with hypoxia group, the cell nucleus expression of YAP cell is gretaly increased(<i>P</i><0.01). <p>CONCLUSION: Apelin-13 can be used to prevent the retinal Müller cells apoptosis caused by the hypoxia, which may be related to the regulation of YAP into the nucleus.
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@#AIM: To analyze the function and mechanism of Apelin-13 in preventing the apoptosis of retinal Müller cells induced by hypoxia.<p>METHODS: In the research, the retinal Müller cells are regarded as research subjects, and the control group, hypoxia group and experiment group are set up. The cells of control group are cultivated in normal environment. The cells of hypoxia group are cultivated in hypoxia environment. The cells of experiment group are cultivated in hypoxia environment and are treated with the Apelin-13(1μmol/L). MTT method is used to monitor the changing of the cell viability, and the crystal violet staining method is adopted to observe the cell morphology. In addition, the immunofluorescence staining method is used to test the expression of GFAP and YAP and the TUNEL staining method is used to monitor the cell apoptosis situation and the apoptosis index is calculated. The protein staining method is used to observe the changing of the expression of p-LATS1, p-YAP, LATS1 and YAP protein. <p>RESULTS:The separated and extracted Müller cells grow on the wall and show elongation, polygon and circular shapes. The cytoplasm is plentiful and the cell nucleus show circular shape. The GFAP expression of the cell is positive. The treatment with 0.1, 1, 10μmol/L Apelin-13 can obviously prevent the Müller cell viability decreasing induced by hypoxia(<i>P</i><0.05 or <i>P</i><0.01). Compared with the control group, the cell apoptosis index of hypoxia group is obviously increased(<i>P</i><0.01). However, compared with the hypoxia group, the cell apoptosis index of experiment group is obviously decreased(<i>P</i><0.01). The p-LATS1 and p-YAP protein expression of the control group and hypoxia group does not have big difference. Compared with hypoxia group, the p-LATS1 and p-YAP protein expression of experiment group is obviously decreased(<i>P</i><0.01). The YAP protein expression of cell nucleus of control group and hypoxia group does not have great difference. Compared with hypoxia group, the cell nucleus expression of YAP cell is gretaly increased(<i>P</i><0.01). <p>CONCLUSION: Apelin-13 can be used to prevent the retinal Müller cells apoptosis caused by the hypoxia, which may be related to the regulation of YAP into the nucleus.
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Objective To investigate the effect of advanced glycation end products(AGEs)on expression of vascular endothelial growth factor(VEGF)in rabbit retinal M?ller cells in vitro.Methods We successfully cultured rabbit retinal M?ller cells and made AGEs-BSA as well as its control in vitro.Study with M?ller cells were divided into AGEs-BSA group,AGEs-BSA control group and blank control group.AGEs-BSA group and AGEs-BSA control group were respectively treated with 5 different concentration series of AGEs-BSA and AGEs-BSA control and cultured for 3,6 and 9 days,while blank control group was incubated without any intervention.Then VEGF expression in M?ller cells was observed by immunocytochemistry(ICC).Results Compared with control group,VEGF expression in cultured retinal M?ller cells was significantly enhanced in AGEs-BSA group.And the effects were in the time-and concentration-dependent manners.Conclusions AGEs increases VEGF expression in rabbit retinal M?ller cells in vitro,which indicates that AGEs may promote the progression of diabetic retinopathy(DR)through the induction of VEGF expression.
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Objective To investigate the expression period of bFGF and the correlation between the M?ller cells in retina and the increasing of bFGF expression in diabetic rabbits.Methods Sixteen rabbits were divided randomly into normal control and diabetic groups.After the models of diabetic rabbits were set up,the rabbits were breeded for 7 weeks.The immunofluorescence double labeling method and laser confocal microscopy were used to observe the ratina of the diabetic rabbits and the position fixing of bFGF was studied.Results In normal control group,the structure of each layer of retina was clear,the cell lined up tightly and regularly with normal shape,the location with red fluorescence was M?ller cells signaled with GFAP,labeled with bFGF,only on capillary basement membrane the red fluorescence could be found.In diabetic group,the structure of each layer of retina was clear,the cells of INL and GCL lined up loosely,the intercellular space increased,there was no significant difference compared with normal group on cell shape.Labeled with bFGF,the different intensity red fluorescence could be found in each layer cells,double labeled with GFAP and bFGF,the yellow fluorescence could be found.The retinopathy of diabetic rabbit was in BDR stage.The expression of bFGF increased in this stage.The bFGF and GFAP coexpressed in M?ller cells.Conclusion The bFGF begins to express in the M?ller cells from the BDR stage.
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Objective To investigate the effect of hypoxia on expressions of erythropoietin(EPO)mRNA and protein in retinal M?ller cells cultured in vitro. Methods Retina tissues from the new-born Wistar rats were dissected into cell suspension after digested by pancreatin.M?ller cells were separated and purified by mechanical concussion and blowing and striking method.The expression of EPO mRNA and protein under the condition of hypoxia was detected by semi-quantitative reverse transcriptase(RT)-polymerase chain reaction(PCR)and immunocytochemical method. Results Retinal M?ller cells were cultured successfully,95% of which were positively stained by glial fibrillary acidic protein(GFAP).Positively stained EPO protein was located in the cytoplasm and protuberance.The expression of EPO mRNA and protein was faint in the normal retinal M?ller cells,but increased obviously and time-dependently after hypoxia. Conclusion Expression of EPO mRNA and protein increases in M?ller cells after hypoxia,which may be one of the protective factors for the nerves in anoxic retinopathy.
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Objective To investigate the effect of long-term intraocular retention of domestic perfluorocarbon liquid (PFCL) on morphology and histology of ocular tissues. Methods A total of 18 New-Zealand rabbits were randomly divided into 3 experimental groups, whose left eyes underwent intraocular injection with 0.3, 0.6, and 1.0 ml PFCL, respectively. All of the right eyes of the rabbits were in the control group. The morphological, electrophysiological and histological changes of the ocular tissue were observed 4, 8, and 12 weeks after the injection. Results No clinically significant retinopathy but only mild morphological changes were found in group 1 and 2, while obvious morphological and histological changes were found in group 3. Mild morphological and histological changes were found in all of the rabbits 4-8 weeks after the injection while significant ones were found 8-12 weeks after the injection. The results of electroretinography indicated a statistically significant decline of amplitude of b wave in group 3. Conclusions Long-term intraocular retention of few PFCL may cause mild histological changes but not affect the clinical function. Plentiful PFCL remains in eyes may lead to toxic reaction to the ocular tissue.
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Objective To investigate the expression of induced heat shock protein (HSP) 70 in rat′s retinal neurons (RNs) and M?ller cells, and evaluate the protective effect of HSP 70 on RNs injured with glucose deprivation and glutamate. Methods Rat′s RNs and M?ller cells cultured in vitro were treated with heat shock (42℃ for 1 hour), and duration of the expression of HSP70 was detected by immunocytochemical techniques. Viability of the cells was measured by methyl thiazolyl tetrazolium (MTT) chromatometry after incitant toxic injury with glucose deprivation (0.56 mmol/L glucose for 6 hours) and glutamate (100 ?mol/L for 6 hours). Simultaneously, the expression was interdicted by HSP70. Results Hypereffective expression of HSP70 was found in cultured RNs and M?ller cells after heat shock. The viability of RNs pretreated by heat shock after injured with glucose deprivation and glutamate significantly increased which could be interdicted by HSP70 antibody. Conclusion Hypereffective expression of HSP 70 may be induced by heat shock, which enhances the ability of tolerance of RNs to the incitant toxic injury by glucose deprivation and exitotoxicity.
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Obiective To investigate the change of the activity of proliferation in cultivated M?ller cells treated by advanced glycation endoproducts (AGEs), and the effect of these changes on expression of occludin in bovine retinal vascular endothelial cells (BREC). Methods The cultivated M?ller cells were devided into normal growth group and cultured with AGEs group. The cultured BREC were devided into 4 groups:group 1, without any medium; group 2, with normal growth M?ller cell medium (MCM); group 3,MCM treated by AGEs; group 4, without cell as the control. Enzyme-linked immuno sorbent assay was used to detect the content of occludin in the medium in the 4 groups. Results The content of expression of occludin was the most in group 2, less in group 1, and the least in group 3. Conclusion AGEs may promote the abnormal proliferation of M?ller cells and inhibit the expression of occludin in BREC.
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Objective To observe the effects of static pressure on the number of cultured retinal M?ller glial cells(RMGC)and expression of glial fibrillary acidic protein(GFAP)and heat shock protein(HSP)70 by these cells.Design Experimental study. Participants Cultured rat RMGC.Methods Rat RMGCs were cultured and identified according to previous method described by Reichenbach.These cells were treated with different static pressures and divided into 4 groups:A(1.33kPa),B(2.67kPa),C(5.33kPa)and D(10.67 kPa)while the cells without treatment was as control group(NC).The morphologies of RMGC in these groups were observed under inverted phased contrast microscope,the number of RMGC counted with conservative method and the viability were studied with trypan blue staining.The expressions of GFAP and HSP70 in RMGCs were detected with the method of western blot.Main Outcome Measures The morphologies of RMGC,cell number,cell viability.Results There were pressure-dependent changes of RMGC number. The cell number of group C and D was less than that of group NC,A and B(P＜0.01).High static pressure resulted directly in the decreased ratio of unstained RMGCs(P＜0.01).The ratio of unstained RMGCs in group C and D was less than that in group NC,A and B(P＜0.01).Many cells in group C and D were injured and the higher the pressure elevated,the more the degree of injury became.The expressions of GFAP and HSP70 in group NC were less than other pressure treated groups and the expression of GFAP in group C and D was higher than that in group A and B.There was no obvious difference between these pressure treated groups.Conclusions High static pressure could cause the injuries of RMGCs.The increased expression of GFAP and HSP70 in RMGC might be regarded as a sign of retinal injury response to high intraocular pressure.