Mouse Model of Acute to Chronic Kidney Disease Transition Induced by Renal Ischemia/Reperfusion Injury.

Abstract

Surgical transient occlusion of the renal pedicle induces renal ischemia-reperfusion injury (IRI), a widely used model for studying acute kidney injury (AKI) and its progression to chronic kidney disease (CKD) in mice. However, conventional protocols often either preclude serum-based functional assessment or yield high mortality. While existing unilateral and bilateral renal IRI models emphasize reproducibility, challenges remain in achieving both consistent injury severity and long-term survival suitable for studying CKD progression. Here, we present a dorsal approach protocol that provides a robust and reproducible model of the ischemic AKI-to-CKD transition. The dorsal approach facilitates straightforward access to the kidneys and minimizes intra-abdominal manipulation. We use unilateral renal IRI combined with contralateral nephrectomy performed one day prior to blood and tissue collection. This approach offers two main advantages: (1) it minimizes variability by avoiding the inconsistencies associated with bilateral injury, and (2) it achieves nearly 100% survival while maintaining consistent injury, in contrast to protocols in which nephrectomy is performed earlier and associated with higher mortality. Functional evaluation is performed by serum BUN and creatinine, and interstitial fibrosis is quantified by Masson's trichrome-based collagen deposition and CKD marker genes at 28 and 42 days after renal IRI. Together, these readouts provide complementary insight into functional impairment and the development of tissue pathology. This protocol establishes a reliable and versatile model of ischemic-CKD in mice for mechanistic investigations.