Hypoxia-inducible Factor-1α Specific Interfering RNA Inhibits The Expression Of HIF-1α In The Retina Of Mice

Objective: To investigate the inhibitory effect of HIF-αspecificsiRNA recombinant plasmid pSUPER^siHIF-1α on the expression of HIF-1αand retinal neovascularization in mice.Methods: (1) HIF-1αspecific siRNA was constructed (pSUPER^siHIF-1α).(2) There were 12 seven-day-old C57BL/6J mice in the normal group and36 mice which were divided randomly into control group,vector groupand gene therapy group were induced for retinal neovascularization byhypoxia according to Smith's method.Liposome with vector plasmid andpSUPER^siHIF-1α were injected into the vitreous in the vector group, andgene therapy group respectively 1 day before mice were moved out toroom air from the cabin. (3) FITC-Dextran angiography was used toobserve the pattern of the retinal vascular.(4) HIF-1αmRNA expression ofretina was detected with reverse transcriptase polymerase chain reaction(RT-PCR). (5) The expression of HIF-1αprotein among each group wasdetected using SP immunohistochemistry.Results: (1) Retinal flat-mounts after FITC-Dextran angiographyindicated that the vessels of normal mice formed a fined radial branchingpattern in A group.While the large vessles were distored, the capillarywas obstructed, lots of neovascular tuffs proliferated and fluorescenceleaked in the periphery of the retina in B and C groups. After transfection of pSUPER^siHIF-1α into the retina,the retinal neovascularization andnon-perfusion distraction in gene therapy group(D) reduced and thestructure of retina were more regular than B and C. (2) The expression ofHIF-1αmRNA in retina was increased significantly in the control andvector groups as compared with normal group,while decreased 57.1% ingene therapy group as compared with control group (P＜0.01). (3)Immunohistochemical staining showed that HIF-1αexpressed mainly inthe retinal ganglion cell layer in B and C groups,while no expression in Agroup. After transfection of pSUPER^siHIF-1α into the retina, the expressionof HIF-1αprotein decreased 51.5% as compared with B group.Conclusions: The development of retinal neovascularization isinhibited markedly by intravitreal injection of HIF-1αspecific recom-bineant plasmid pSUPER^siHIF-1α through down-regulating the expressionof HIF-1αin mice.