Effect Of Avastin On The Expression Of AQP-4 In Müller Cell Under Hypoxia

Objective The aim of this study was to investigate the effects of Avastin on AQP4 expression in human retinal Müller cells in vitro under hypoxia, So as to explore the mechanism of treating retinal edema with Avastin.Methods The human Müller cells were cultured using the enzymatic digestion method. Müller cells were identified by microscope observation, transmission electron microscope analysis and immunofluorescence staining. With semi-quantitative reverse transcription polymerase chain reaction(RT-PCR), the hypoxic model was set up by detecting the expression of AQP4mRNA and VEGFmRNA in Müller cells cultured under 500μmol/L CoCl₂ for 6, 12, 24 hours and under 100μmol/L,300μmol/L,500μmol/L,700μmol/L CoCl₂ for 24 hours. The expression of AQP4mRNA in Müller cells cultured under 50ng/ml exogenous vascular endothelial growth factor(VEGF)for 12, 24 hours and under 25ng/ml, 50ng/ml, 75ng/ml VEGF for 24 hours were detected with RT-PCR. Amplified cDNA products of AQP4mRNA in Müller cells cultured under 500μmol/LCoCl₂ and 200μg/ml Avastin for 24 hours were detected with RT-PCR.Results Human retinal Müller cells can be cultured successfully using an enzymatic digestion method. Human retinal Müller cells show green fluorescene in the cytoplasm under fluorescene microscope . Characteristic 8～10nm intracellular filaments could be seen in the cytoplasm under the transmission electron microscope. In the CoCl₂ experime- ntal groups, the expression of AQP4mRNA and VEGFmRNA in Müller cells was increas- ed compared with the control.Alteration of AQP4mRNA and VEGFmRNA levels showed a significant positive correlation(r=0.952, P<0.05). In the VEGF experimental groups, the expression of AQP-4mRNA in Müller cells was correlated with the time and the increase of VEGF. The expression of AQP4 mRNA was significantly decreased by Avastin compa- red with the control.Conclusion Normal human retinal Müller cells present AQP4 and VEGF. The expression of AQP4mRNA and VEGFmRNA in Müller cells was increased by the CoCl₂. The expression of AQP4mRNA in Müller cells was enhanced by the VEGF. The in vitro study suggests that Avastin could decrease the expression of AQP4 mRNA in human Müller cells under hypoxic conditions partial by VEGF path.