PI:Demitrios Vavvas, M.D.
Abstract:Diabetic retinopathy is a major cause of blindness. Its exact pathophysiology is still unclear. My laboratory’s long term goal is to elucidate the regulatory mechanisms controlling disease pahthophysiology as a prerequisite to the development of novel and better therapies. The specific hypothesis behind the proposed research is that AMP dependent kinase (AMPK) is a major regulatory factor controlling progression of diabetic retinopathy. I am basing this hypothesis on a) the observation that Vascular Endothelial Growth factor (VEGF) has been implicated in diabetic retinopathy progression, b) that AMPK has been shown to be upstream of VEGF in other disease models, and c) that intraocular pharmacologic activation of AMPK leads to vasculopathy. Based on these observations, the experimental focus of this proposal is on the role of AMPK in diabetic retinopathy. The specific aims are to:
1. Define the effects of diabetes mellitus on the expression and activity of different AMPK isoforms in the retina of mice. I will induce diabetes by streptozotocin and high galactose diet and at various time points after disease initiation I will examine activity of the enzyme by immunoprecipitation and protein levels and localization of AMPK isoforms by Western blots and immunocytochemistry.
2. Examine the effects of AMPK knockout on diabetic retinopathy progression. Wild type and AMPK isoform specific knockout mice will be rendered diabetic and diabetic retinopathy progression will be assessed at different time points by examining blood retinal barrier breakdown, white blood cell adhesion and levels of previously established pathologic factors in diabetic retinopathy such as VEGF.
This proposal is so designed that it can examine both a positive and a negative role of AMPK on diabetic retinopathy progression.
PI:Paolo Fiorina, M.D.