MiRNA-21-HIF-1α-VEGF Axis Is Associated with Myopic Choroidal Neovascularization in Guinea Pigs

Myopic choroidal neovascularization (CNV) often causes serious damage to central vision. The mechanisms behind it remain unclear.

In this study, monocular form deprivation was applied to induce high myopia, and 532-nm laser was employed to induce CNV in guinea pig. The development of neovascularization was measured comprehensively by fundus fluorescein angiography, optical coherence tomography and hematoxylin and eosin staining. Gene expression was detected by real-time polymerase chain reaction and immunohistochemistry.

The proliferation of new blood vessels increased with time and peaked at 21 days. At each time point after laser photocoagulation, the incidence of CNV was higher in form-deprived myopia (FDM) group than in control group. Myopic CNV started earlier and decreased more slowly. The obvious continuous fluorescein leakage could last as long as 1 month. The expressions of hypoxia-inducible factor (HIF)-1α and vascular endothelial growth factor (VEGF) increased and peaked at 14 days in both groups after laser photocoagulation. Moreover, after laser photocoagulation, miR-21 expression was upregulated in both groups, reached a peak at 7 days, with a level much higher in FDM group. In addition, miR-21 expression was positively correlated with VEGF and HIF-1α expression in both groups.

miR-21 correlated with HIF-1α-VEGF signaling pathway may promote CNV formation in high-myopia guinea.