Diabetes Induced Changes in Podocyte Morphology and Gene Expression Evaluated Using GFP Transgenic Podocytes

The effect of diabetes in vivo has not been examined on isolated podocytes. To achieve this, GFP was expressed constitutively in podocytes of PGFP transgenic mice which were bred to OVE mice to produce diabetic OVE-GFP mice. Viewing GFP fluorescence, foot processes of OVE-GFP podocytes were visually and measurably effaced, which did not occur with less severe STZ diabetes. Over 300,000 podocytes were purified from each PGFP mouse but only 49,000 podocytes per diabetic OVE-GFP mouse. The low yield from OVE-GFP mice appeared to be due to more fragile state of most OVE-GFP diabetic podocytes which did not survive the isolation process. Diabetic podocytes that were isolated had high levels of the lipid peroxidation product 4-HNE and they were more sensitive to death due to oxidative stress. Gene array analysis of OVE-GFP podocytes showed strong diabetes induction of genes involved in inflammation. Four CXC chemokines were induced at least 3-fold and the chemokine CXCL1 was shown for the first time to be specifically induced in podocytes by OVE, dbdb and STZ diabetes.