Mitigating Female Aging Kidney Damage from Ischemic Reperfusion Injury Using Renal Progenitor Cells

Abstract

Acute kidney injury (AKI) is a sudden event that damages the kidney and disrupts normal function by various causes, such as ischemia, exposure to substances, or obstructions. With AKIs affecting 1 out of 5 hospitalized patients and their association with increased risk of chronic kidney disease (CKD), finding an effective treatment for AKIs is of vital importance. One possible treatment for AKIs could be found within the realm of progenitor cell therapy. Progenitor cells are currently used in the treatment of hematological diseases with the burgeoning information on their possible uses for other disorders. The purpose of this study was to determine whether there is a resident population of renal progenitor cells (RPCs) within the kidney and if these cells can be utilized as an effective treatment to mitigate aging AKI by decreasing inflammation through alteration of the M1:M2 macrophage ratio. This study utilized 75-78 weeks old C57BL/6J female mice to determine if RPCs can reduce the damage caused by ischemic reperfusion (IR)-induced AKI. Kidneys were harvested from young female (40 days old) mice and digested in collagenase type 1 to remove connective tissue. Cells were sorted by flow cytometry, positively selected for c-Kit using magnetic nanoparticles, and subsequently stained for Sca1 and Oct4. Aging female mice underwent renal IR injury (IRI) by clamping off the renal artery and vein for 27 minutes. Following reperfusion, the triple-positive cells were suspended in DMEM and injected into the kidney over the course of 8 minutes to reduce the possibility of pressure necrosis. A separate group of mice was injected with saline to serve as control. The mice were monitored for 3 days at which point kidney function was assessed and tissue harvested for biochemical analysis. Our results indicated an increase in inflammatory cytokines IL-17, NF-κB, and IL-6 in IRI mice which were mitigated with RPCs treatment along with an increase in anti-inflammatory marker IL-10. Furthermore, an increase in M1 macrophage markers was measured in IRI, and a trending increase in M2 macrophage markers in IRI animals treated with RPCs. The kidney function of IRI animals treated with RPC showed improvement compared to IRI control. In summary, we found a population of cells positive for three progenitor cell markers: c-Kit, Sca1, Oct4, and treating IRI aging female kidney with these cells reduced inflammatory markers along with an increase in kidney function, suggesting RPCs promote recovery from AKI by reducing inflammation. Grant Support: DK116591. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.