[TERT-siRNA inhibits oxygen-induced retinal neovascularization in mice].

OBJECTIVE

To investigate the inhibitory effect of small interfering RNA (siRNA) targeting TERT on murine retinal neovascularization and explore the feasibility of potential therapeutic approach in retinal vascular disease.

METHODS

Two recombinant plasmids TERT siRNA (pSIREN-mTERT-1) and negative plasmid (pSIREN-mTERT-N) were constructed and 80 seven-day-old C57BL/6J mice were divided randomly into therapeutic group (A), negative plasmid group (B), oxygen-induced retinopathy group (C) and normal control group (D), 20 mice in each group. Group A, B and C were exposed to 75% +/- 2% oxygen for 5 days and then to room air, which induced mice retinal neovascularization. Groups A and B were injected two kinds of the above recombinant plasmid into the murine vitreous on the 12th day. The mice of group D were raised in normal oxygen circumstance. On the 19th day, 2% Evens blue angiography was used to observe the pattern of the retinal vascular. Expression of TERT mRNA were confirmed by reverse-transcription polymerase chain reaction (RT-PCR) and Real-time PCR. Histological observation and vascular endothelial cells counting were used to examine the effects of siRNA on the retinal neovascularization.

RESULTS

Retinal flat after Evans blue angiography indicated that the vessels of group A formed a fine radial branching pattern, which was similar to normal mice. In group A, the retinal neovascularization reduced and the structure of retina were more regular than group B and C. At the same time the large vessels were distorted, neovascular clusters proliferated and fluorescence leaked in the middle and periphery area in group B and C. RT-PCR and Real-time PCR showed the expression of TERT mRNA was downregulated in group A compared with groups B and C (P < 0.05). Paraffin tissue slice with hematoxylin-eosin staining showed that the average counts of vascular endothelial cells which break through the inner limiting membrane in group A were less than groups B and C, the differences were significant (P < 0.05).

CONCLUSION

Pathologic retinal neovascularization can be inhibited by specific TERT siRNA in vivo, which may be a novel efficient strategy against proliferative vasculopathies.