Involvement of VEGF in both Cell Apoptosis and Survival in the Retina of Type 2 Diabetic OLETF Rats / 대한해부학회지

ABSTRACT

Vascular endothelial growth factor (VEGF) is closely involved in early retinal pathology of diabetes, including blood-retinal barrier breakdown, pericyte loss, neuro-retinal apoptosis, and cell proliferation. This study examines the involvement of VEGF in cell apoptosis and survival in the retina of animals with type 2 diabetes. We used retinas from 28-week-old Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a model of spontaneous type 2 diabetes, and Long-Evans Tokushima Otsuka (LETO) rats as controls. In parallel with evidence for pericyte loss, we found cell proliferation, apoptosis, and endothelial nitric oxide synthase (eNOS) (an indicator of endothelial cell proliferation/survival) and VEGF overexpression in the OLETF-retina, compared to control LETO. Furthermore, apoptotic signals were partly co-localized to only VEGF-positive cells in the OLETF-retina, but no apoptotic signals were found in VEGF- and eNOS-double-positive cells. These results suggest that upregulated VEGF is involved in apoptosis and eNOS-dependent cell survival in the retinas of type 2 diabetic rats.