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AlM:To evaluate the expression of transcriptional factor lslet-1 in retina in experimental retinal neovascularization induced by oxygen. METHODS: The murine retinal neovascularization were induced by hyperoxia exposure. The morphological observation of retinal neovascularization was performed using angiography by fluorescein dextran injection under the fluorescence microscope, and the new blood vessels were quantified after 5d in room air (17-day-old) by counting the vascular epithelial cell nuclei protruding into viteous cavity using HE stain. Realtime PCR and Western blot were used to examine retinal lslet-1 level in postnatal 7,12, 14,17 and 26d respectively. RESULTS: A lots of new blood vessels were demonstrated in the mouse retina in hyperoxic group by fluorescein angiography and histological method. Moreover, no significant difference was found in retinal lslet-1 level in postnatal 7d between hyperoxic group and control group, but was significantly higher in postnatal 12, 14 and 17d mice compared with control mice. However, mice at postnatal 26d, expression of lslet-1 in retina decreased to normal level. CONCLUSlON: ln processing mouse model of retinal neovascularization, sustained hypoxia retinal tissue induce retinal neovascularization by increas the expression of transcription factor lslet-1.
RESUMO
<p><b>OBJECTIVE</b>To study the inhibition effect of HIF-1α specific siRNA expression vector pSUPERH1-siHIF-1α on retinal neovascularization in a mouse model of retinopathy of prematurity (ROP).</p><p><b>METHODS</b>The mouse model of ROP was prepared by the method Smith described. Forty-eight ROP mice were randomly divided into two groups: an experimental group that was intravitreously injected with pSUPERH1-siHIF-1α and a control group that was injected with pSUPER retro vector. The levels of HIF-1α and vascular endothelia growth factor (VEGF) in the retina were examined by Western blot. The retinal neovascularization was evaluated by angiography using FITC Dextran and quantitated histologically.</p><p><b>RESULTS</b>The levels of HIF-1α and VEGF in the retina in the experimental group were reduced 90% and 65% respectively compared with those in the control group. Meanwhile, the number of retinal neovascular endothelial nucleus outbreaking the inner limit membrane in the experimental group was significantly reduced compared with that in the control group.</p><p><b>CONCLUSIONS</b>The development of retinal neovascularization of ROP can be markedly inhibited by RNA interference targeting HIF-1α.</p>