Abstract
Purpose: :
The aim of this work is studying the therapeutic potential of the topical application of siRNAs against HIF, in order to reduce the corneal neovascularization.
Methods: :
New Zealand White rabbits were used. The corneal injuries were made by the application of sectors of filter paper (Whatman#1) soaked in NaOH 1N for 15 seconds. The sectors were applied on the ocular surface during 1 minute with the vertex in the centre of the cornea. After this, the sectors were removed and the eyes were washed with saline 0,9% to eliminate the NaOH. The siRNAs were tested in vitro in the immortalised SIRC cell line and the best ones were chosen for the in vivo experiment. Three siRNAs were tested for the in vivo experiment. The siRNAs application were made during 4 days, following the injury, in one eye being the other the control with saline 0,9%. The images of the neovascularization were taken with a slit-lamp the days 0, 7, 14, 23 and 28th and analyzed by the ImageJ software.
Results: :
The in vitro results showed a different reduction in the expression of HIF of 80% for the siRNA1, and 50% for the siRNA2 and siRNA3. The results in vivo showed a drop in the neovascular area of 80% for the siRNA2, 40% for the siRNA3 and 20% for the siRNA1. The parameter NV50, where the neovascular area reaches the 50% of the total, in days, showed a value of 10,2 ± 2,46 days for the control and a value of 4,8±1,8 days for the siRNA2.
Conclusions: :
The siRNAs against HIF protein tested for the corneal neovacularization process reduced in vitro the expression of the mentioned protein and in vivo, the angiogenesis observed in the ocular surface. The NV50 parameter showed the best efficacy for the siRNA2 in vivo. All the tested siRNAs could be potential therapeutic agents for the angiogenic process.
Keywords: neovascularization • hypoxia • RNAi