137 Protocol optimization for adenine nephropathy in Ahr genotype-divergent mouse strains

Objectives/Goals: To determine the optimal adenine nephropathy induction protocol in C57BL6/J and Sv129 mice. Optimization is defined by the combination of the highest mean serum creatinine and best survival rate at20 weeks, accounting for the influence of sex. Methods/Study Population: We will use 8-week-old male and female wild-type C57BL6/J (Ahr^b) and Sv129 (Ahr^d) mice (n=120). Mice will be randomized into groups (n =10pergroupwith equal numbers of males and females) comparing two adenine diet protocols (0.25% for 2 weeks vs. 0.25% every other week for 6 weeks) against normal chow controls, which will allow us to investigate the impact of genetic background on disease severity. Renal function will be monitored via weekly weights and blood/urine collection at 16 and 20 weeks. Cardiac function will be assessed by echocardiography at 16 and 20 weeks to characterize chronic kidney disease-associated heart disease. Tissue (kidney, heart, brain) will be collected at human endpoint or20 weeks for downstream analysis. Statistical comparisons will primarily focus on diet effect within same sex and strain groups. Results/Anticipated Results: We anticipate identifying a superior adenine feeding protocol for each sex and strain combination based on the primary endpoints (creatinine and survival). Sex differences are expected, with males likely developing more severe nephropathy across both strains. The optimized protocol for each group will provide a standardized model for future research into uremic toxin. Discussion/Significance of Impact: Establishing a strain-specific adenine nephropathy protocol is vital for advancing CKD research. This work provides a foundation for accurately investigating the role of uremic toxins in both renal failure and CKD-associated cardiovascular disease, which is a major cause of death in CKD patients.