Podocyte Density and Albuminuria in Aging Diabetic Ins2± Mice with or Without Adenosine A1 Receptor Signaling.

Abstract

Aim of StudyTo investigate podocyte density in aging diabetic Ins2± and Ins2±, A1AR-/- mouse models in C57Bl/6 background.MethodsIns2± mice and especially Ins2±, adenosine A1 receptor knockout mice (Ins2±, A1AR-/-) are mouse models with a phenotype of diabetic nephropathy. Aged mice (at ~40 weeks) were assessed for glomerular filtration barrier function by measuring albuminuria, glomerular filtration, glomerular damage by electron microscopy, and podocyte numbers by Wilms Tumor protein (WT-1) staining.ResultsCompared to healthy wild-type mice, both diabetic mouse models developed diabetic nephropathy, including hyperfiltration (p<0.01) and albuminuria (p<0.05). Typical diabetic structural glomerular and podocyte damage was visualized by electron microscopy. Podocyte count per glomerular area (podocyte density) was significantly decreased in both diabetic mouse models (p<0.01). In contrast, no significant correlation was detected between albuminuria and absolute podocyte count per glomerulus.ConclusionThe amount of albuminuria as marker of diabetic nephropathy does not correlate with the podocytes density; however, a relative podocyte deficiency became evident with an increase in glomerular area in the diabetic animals, suggesting a relative podocytopenia.