Novel mouse model of CRVO induced by intraperitoneal injection of Rose Bengal with laser radiation

Abstract

Purpose : Although anti-VEGF drugs are used for macular edema associated with central retinal vein occlusion (CRVO), it is not a curative therapy. Therefore, a simple animal model is desired for developing novel therapeutical approaches. In this study, we developed a novel CRVO mouse model by using the intraperitoneal injection of Rose Bengal and low-power laser radiation, and examined its pathological features.

Methods : C57BL / 6J 9-12 week-old male mice were injected intraperitoneally with 1 mg of Rose Bengal under anesthesia (N=13). Three minutes later, the central retinal vein was radiated with a low-power laser having a wavelength of 532 nm, an output power of 50 mW, a radiation time of 3 seconds, and a radiation diameter of 50 μm, and it was repeated until vein occlusion. Fluorescence fundus angiography was performed 24 hours later, and the eyes in which with retinal nonperfusion area were enucleated and retinal gene expression was analyzed (N=3). Furthermore, on the 7th day after the operation, Fluorescein Isothiocyanate (FITC) was injected under anesthesia, a retinal flat mount was prepared, and further lectin staining was carried out (N=10).

Results : In retinas of the CRVO group, the expression of VEGF (1.9 folds), inflammatory cytokines IL-6 (64 folds), TNF-α (4.2 folds), IL-1β (3.6 folds), and inflammation and adhesion molecule ICAM-1 (20 folds) was significantly upregulated compared with the untreated group. Furthermore, the expression of adrenomedullin (AM), a peptide that possesses vaso- and neuroprotective functions, increased to 10 folds, while the expression of RAMP2, an AM’s receptor binding protein, decreased to 1/10. Nonperfusion area and CRVO-like findings were obtained in 7 out of 10 eyes subjected to fluorescence fundus angiography examination after 1 week. The non-perfusion site of FITC was coincided with the reduced lectin-staining sites; therefore endothelial cell damage in this CRVO model was confirmed.

Conclusions : The CRVO model using Rose Bengal intraperitoneal injection and low power laser irradiation is simpler than conventional tail vein injection and is useful for therapeutic research.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.

 

Fds photo of 7days after laser

 

FAG of 7days after laser