Materials and methods for the treatment of pathological neovascularization in the eye
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.
1. A method of reducing or preventing ocular neovascularization in a subject, wherein the method consists of administering, into one or more target ocular tissues of the subject, said target ocular tissues selected from the group consisting of the retinal, choroidal and corneal ocular compartments, an expression vector comprising a transgene encoding a therapeutic molecule, wherein the transgene is operably linked to an ocular-specific promoter and becomes hypoxia-responsive when said ocular-specific promoter is placed under the control of a hypoxia responsive element and selectively drives gene expression in retinal cells, retinal pigment epithelial cells, Muller cells, choroid cells and combinations thereof;
wherein said hypoxia responsive element is a hypoxia regulated silencing element (HRSE) including at least one hypoxia responsive element (HRE) sequence which upregulates gene expression under hypoxia or inflammation and at least one neuron-restrictive silencer element (NRSE) sequence which silences gene expression under normoxia,
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 or inflammation but not under normoxia,
whereby ocular neovascularization is reduced or prevented.
2. The method of claim 1 , wherein the HRSE includes at least three copies of the hypoxia response element (HRE) sequence.
3. The method of claim 1 , wherein the HRE sequence includes SEQ ID NO:1 or SEQ ID NO:2.
4. The method of claim 1 , wherein the HRSE 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.
5. The method of claim 1 , wherein the ocular-specific promoter selectively drives gene expression in retinal pigment epithelial cells.
6. The method of claim 1 , wherein the ocular-specific promoter is a RPE 65 promoter sequence.
7. The method of claim 1 , 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.
8. The method of claim 1 , wherein the therapeutic molecule is an angiogenesis inhibitor.
9. The method of claim 8 , wherein the angiogenesis inhibitor is selected from the group consisting of endostatin, a fibroblast growth factor (FGF)receptor, a VEGF receptor, angiostatin, pigment epithelium-derived factor (PEDF), platelet factor 4 (PF-4), and combinations thereof.
10. The method of claim 9 , wherein the angiogenesis inhibitor is endostatin.
11. The method of claim 1 , wherein the expression vector is an AAV vector.
12. The method of claim 1 , used to prevent or treat choroidal neovascularization.
13. The method of claim 1 , used to prevent or treat neovascularization in 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.
14. The method of claim 1 , used to prevent or treat retinal and/or corneal neovascularization.
15. The method of claim 1 , wherein the expression vector is administered via subretinal injection.