Click on image to view larger version.
Figure 1. Expression of endostatin in the retina 4 wk after subretinal injection of BIVendostatin reduces VEGF-stimulated vascular permeability. Adult C57BL/6 mice were given subretinal injections of 1.5 x 106 transducing units (TU) of BIVendostatin in the right eye and 1.5 x 106 TU of BIVnull in the left eye. Four wk after vector injection, mice were killed and ocular frozen sections were immunohistochemically stained for endostatin using HistoMark red, which provides a red reaction product. Eyes injected with BIVendostatin (A, B) showed heavy staining for endostatin in RPE cells (B, large arrows) and throughout the inner nuclear layer with dense staining of the walls of some blood vessels (B, arrows). The linear stained structures in the inner plexiform layer (B, arrowhead) are typical of Muller cell processes. Eyes injected with BIVnull showed reaction product along the internal limiting membrane (C, arrowheads) and Bruch’s membrane (arrows), which is likely to be due to cross-reactivity with collagen XVIII, a known component of these membranes. D) Adult double transgenic IRBP/rtTA-TRE/VEGF mice (n=20) were given a subretinal injection of 1.5 x 106 TU of BIVendostatin in the right eye and 1.5 x 106 TU of BIVnull in the left. Four wk after vector injection, mice were started on 2 mg/mL of doxycycline in their drinking water and on day 3 of treatment retinal vascular permeability was measured using [3H]mannitol as tracer. The retina to lung (RLLR) was significantly reduced in eyes expressing endostatin compared with fellow eyes that had been injected with null vector. Statistical comparisons were made with a paired t test. Bar = 100 µm
