Subconjunctival injection of recombinant AAV-angiostatin ameliorates alkali burn induced corneal angiogenesis.
OBJECTIVE
To evaluate the effect of subconjunctival injection of recombinant adeno-associated virus (rAAV)-angiostatin in alkali burn-induced corneal angiogenesis.


METHODS
Adeno-associated viral vector-mediated gene delivery into extraocular tissue was determined by fluorescent microscopy three weeks after subconjunctival injection of viral vector expressing green fluorescent protein (rAAV-GFP). Subconjunctival injection of recombinant adeno-associated viral vector expressing human angiostatin (rAAV-angiostatin) and blank rAAV viral vector (control) was performed in the left eye of male Sprague-Dawley rats (n=6). Alkaline induction of corneal neovascularization (NV) was performed three weeks later. Corneal NV regression was analyzed 7-14 days after alkali burn with slit lamp and digital pictures. Transgenic expression of angiostatin in the cornea, conjunctiva, retina, and muscle insertions was confirmed by reverse-transcriptase polymerase chain reaction (RT-PCR).


RESULTS
Transgenic GFP gene expression was detected mainly in the muscle fibers at the extraocular muscle (EOM) insertions after subconjunctival injection. The area of corneal neovascularization was significantly lower in eyes injected with rAAV-angiostatin (p<0.01) than in eyes injected with the control virus. RT-PCR demonstrated that the angiostatin gene expression was highly detectable in muscle fibers and not detectable in the conjunctiva, cornea, and retina.


CONCLUSIONS
Subconjunctival injection of rAAV-angiostatin reduced alkali burn-induced corneal angiogenesis. We proved the concept that ocular gene therapy by subconjunctival injection of adenovirus-associated gene transfer of angiogenesis inhibitors can be a simple and safe treatment modality that can achieve therapeutic levels and long lasting effects in the treatment of corneal NV induced by ocular surface disorders.
Cheng
Huey-Chuan
HC
Department of Ophthalmology, Mackay Memorial Hospital, Taipei, Taiwan. hccheng@so-net.net.tw
Yeh
Shu-I
SI
Tsao
Yeou-Ping
YP
Kuo
Ping-Chang
PC
D000468:Alkalies / Q000009:adverse effects; D020533:Angiogenesis Inhibitors / Q000235:genetics / Q000627:therapeutic use; D043168:Angiostatins / Q000235:genetics / Q000627:therapeutic use*; D000818:Animals; D002057:Burns, Chemical / Q000150:complications*; D003315:Cornea / Q000098:blood supply; D065306:Corneal Injuries; D016510:Corneal Neovascularization / Q000235:genetics / Q000517:prevention & control*; D000229:Dependovirus; D015536:Down-Regulation; D005126:Eye Burns / Q000139:chemically induced / Q000150:complications*; D015316:Genetic Therapy; D005822:Genetic Vectors; D049452:Green Fluorescent Proteins; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D011995:Recombination, Genetic
D000468:Alkalies; D020533:Angiogenesis Inhibitors; D049452:Green Fluorescent Proteins; D043168:Angiostatins