Materials and Methods for the Treatment of Pathological Neovascularization in the Eye

Abstract

The subject invention provides materials and methods useful in safely and effectively preventing pathological proliferation of blood vessels. The prevention of the over-proliferation of blood vessels according to the subject invention is particularly advantageous for treatment of certain ocular conditions including age-related macular degeneration (AMD), retinopathy of prematurity (ROP) and diabetic retinopathy. In preferred embodiments, the subject invention provides materials and methods for effective treatment of pathological ocular neovascularization using gene therapy. In a specific embodiment the materials and methods of the subject invention can be used to treat AMD.

We claim: 
     
         1 . A method of reducing or preventing ocular neovascularization in a subject, wherein the method comprises administering, into a target ocular tissue of the subject, an expression vector comprising a transgene encoding a therapeutic molecule, wherein the transgene is operably linked to an ocular-specific promoter and is placed under the control of a hypoxia-responsive element,
 wherein the ocular-specific promoter selectively drives gene expression in the ocular tissue having, or at risk of developing, neovascularization,   wherein the hypoxia-responsive element upregulates gene expression under hypoxia but not under nomoxia,   whereby ocular neovascularization is reduced or prevented.   
     
     
         2 . The method of  claim 1 , wherein the hypoxia-responsive element comprises a hypoxia response element (HRE) sequence. 
     
     
         3 . The method of  claim 2 , wherein the hypoxia-responsive element comprises at least three copies of the hypoxia response element (HRE) sequence. 
     
     
         4 . The method of  claim 2 , wherein the HRE sequence comprises SEQ ID NO:1 or SEQ ID NO:2. 
     
     
         5 . The method of  claim 1 , wherein the expression vector further comprises an aerobic silencer that silences gene expression under normoxia. 
     
     
         6 . The method of  claim 5 , wherein the aerobic silencer comprises a neuron-restrictive silencer element (NRSE) sequence. 
     
     
         7 . The method of  claim 5 , wherein the aerobic silencer comprises at least two copies of a hypoxia response element (HRE) sequence and at least two copies of a neuron-restrictive silencer element (NRSE) sequence, wherein the HRE and the NRSE are placed in alternating tandem order. 
     
     
         8 . The method of  claim 1 , wherein the ocular-specific promoter selectively drives gene expression in retinal cells, retinal epithelial cells, Muller cells, or choroid cells. 
     
     
         9 . The method of  claim 8 , wherein the ocular-specific promoter selectively drives gene expression in retinal epithelial cells. 
     
     
         10 . The method of  claim 1 , wherein the ocular-specific promoter is a RPE65 promoter sequence. 
     
     
         11 . The method of  claim 5 , wherein the expression vector comprises, in the 5′ to 3′ direction,
 an aerobic silencer comprising at least two copies of a hypoxia response element (HRE) sequence and at least two copies of a neuron-restrictive silencer element (NRSE) sequence, wherein the HRE and the NRSE are placed in alternating tandem order; 
 at least three copies of the hypoxia response element (HRE) sequence; 
 a RPE65 promoter sequence; and 
 a transgene gene encoding endostatin. 
 
     
     
         12 . The method of  claim 1 , wherein the therapeutic molecule is an angiogenesis inhibitor. 
     
     
         13 . The method of  claim 12 , wherein the angiogenesis inhibitor is selected from endostatin, a fibroblast growth factor (FGF) or VEGF receptor, angiostatin, pigment epithelium-derived factor (PEDF), and platelet factor 4 (PF-4). 
     
     
         14 . The method of  claim 13 , wherein the angiogenesis inhibitor is endostatin. 
     
     
         15 . The method of  claim 1 , wherein the expression vector is an AAV vector. 
     
     
         16 . The method of  claim 1 , used to prevent or treat choroidal neovascularization. 
     
     
         17 . The method of  claim 1 , used to prevent or treat age-related macular degeneration, histoplasmosis, myopic degeneration, choroidal rupture, photocoagulation, choroidal hemangioma, choroidal nonperfusion, choroidal osteomas, choroideremia, retinal detachment, neovascularization at ora serrata, punctate inner choroidopathy, radiation retinopathy, and/or retinal cryoinjury. 
     
     
         18 . The method of  claim 1 , used to prevent or treat retinal and/or corneal neovascularization. 
     
     
         19 . The method of  claim 1 , wherein the expression vector is administered via subretinal injection. 
     
     
         20 . An AAV vector comprising, in the 5′ to 3′ direction, an aerobic silencer comprising at least two copies of a hypoxia response element (HRE) sequence and at least two copies of a neuron-restrictive silencer element (NRSE) sequence, wherein the HRE sequence and the NRSE sequence are placed in alternating tandem order; at least three copies of the hypoxia response element (HRE) sequence; a RPE65 promoter sequence; and a transgene gene encoding endostatin; wherein the endostatin transgene is operably linked to the RPE65 promoter sequence and is placed under the control of the aerobic silencer and the HRE sequence.