Combination of Renin AAV and L-NAME Accelerates the Progression of Kidney Disease in Diabetic Mice

Background: Diabetic kidney disease (DKD) is a major cause of end stage kidney disease with increasing prevalence worldwide. Rodent models that recapitulate human disease are currently lacking, and many existing models show low proteinuria or take a longer time to develop the disease phenotype. Here we describe a rodent model with accelerated disease progression by combining hypertension and reduced nitric oxide bioavailability on the background of hyperglycemia. Methods: Nine-week-old male db/db obese mice (BKS.Cg-+Leprdb/+Leprdb/OlaHsd-00642) from Jackson Laboratories were injected with Renin AAV (1×109 GC) or Lac-Z AAV and provided access to normal chow and water ad libitum. These two groups of mice were further divided into two subgroups each based on uACR and half of each subgroup was switched to drinking water containing L-Name (20 mg/L). The 4 subgroups (Lac-Z AAV + water, Lac-Z AAV + L-Name, Renin AAV + water, and Renin AAV + L-Name) were then followed for 5 weeks. Changes in proteinuria were evaluated every two or three weeks for study duration. In addition, blood pressure was measured via tail cuff and 4 h fasted blood glucose levels measured with a glucometer. At study termination, animals were euthanized, and blood and organs were harvested for further analysis. Results: Mice treated with a combination of Renin AAV and L-Name showed a significant increase in proteinuria compared to Lac-Z AAV + water group, at two weeks and renal dysfunction continued to progress up to five weeks. Blood pressure was not significantly increased during the study. All mice in the study showed hyperglycemia, with blood glucose levels above 600 mg/dL. Gene expression data from the kidney showed increases in markers of kidney injury and fibrosis in the Renin AAV + L-Name treated group compared to Lac-Z AAV + water group. Urinary biomarker data also showed an increased in kidney injury biomarker in the combination group compared to the Lac-Z groups. Conclusion: Our results show that combination of Renin AAV and L-Name markedly accelerates the onset of DKD in male db/db mice, with signs of kidney dysfunction seen at 2 weeks. This model has the potential to be utilized for rapid evaluation of novel therapeutic interventions for DKD. Funding: Commercial Support - Eli Lilly & Company