Inhibition of retinal neovascularization by siRNA targeting VEGF(165).
OBJECTIVE
To investigate whether vector-based vascular endothelial growth factor 165 (VEGF)(165) targeted siRNA expression system (pSilencer(siVEGF)) could inhibit VEGF(165) expression in vitro and suppresses retinal neovascularization in the murine model of oxygen-induced retinopathy.


METHODS
pSilencer(siVEGF), from which siRNA targeting VEGF(165) could be generated, was constructed and transfected to human umbilical vein endothelial cells. Then the level of VEGF isoforms in cultured cells was measured by RT-PCR and ELISA. Intravitreal injection of pSilencer(siVEGF) was performed in mice with ischemic retinopathy. Retinal neovascularization was evaluated by angiography using fluorescein-labeled dextran and quantitated histologically. The levels of VEGF(164), which is equivalent to human VEGF(165) in murine retinas were determined by RT-PCR and western immunoblotting.


RESULTS
Expression of VEGF(165) in cultured cells was greatly curtailed by pSilencer(siVEGF) under both normoxia and hypoxia conditions. However, the other isoforms, VEGF(189) and VEGF(121), were expressed to a similar degree regardless of whether pSilencer(siVEGF) was administered. Based on angiography and histological analysis, retinal neovascularization in the eyes treated with pSilencer(siVEGF) were significantly reduced compared to the control eyes. Furthermore, the VEGF(164) levels in the murine retinas were suppressed by pSilencer(siVEGF).


CONCLUSIONS
Retinal neovascularization in the murine model was significantly attenuated by pSilencer(siVEGF) through decreasing VEGF(164) levels in the retinas. pSilencer(siVEGF) seems to be a potential therapeutic tool for ischemic-induced retinal diseases.
Xia
Xiao-bo
XB
Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, China. xbxia@yahoo.com
Xiong
Si-qi
SQ
Song
Wei-tao
WT
Luo
Jie
J
Wang
Yu-ke
YK
Zhou
Rong-rong
RR
D000792:Angiography; D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured; D004195:Disease Models, Animal; D006801:Humans; D051379:Mice; D034741:RNA, Small Interfering / Q000378:metabolism*; D012160:Retina / Q000378:metabolism / Q000473:pathology; D015861:Retinal Neovascularization / Q000473:pathology*; D042461:Vascular Endothelial Growth Factor A / Q000172:deficiency* / Q000378:metabolism
D034741:RNA, Small Interfering; D042461:Vascular Endothelial Growth Factor A