Cisplatin is a widely used chemotherapeutic agent widely in the treatment regimen of many solid tumors. Cisplatin has dose limiting nephrotoxicity, with approximately 30% of patients developing acute kidney injury (AKI). Patience that experience an AKI event are more likely to develop chronic kidney disease (CKD). There are currently no FDA approved treatments for cisplatin-induced nephrotoxicity or its progression to CKD. The field previously developed a model of cisplatin-induced kidney injury (CDDP-KI) in which rodents are dosed with a single high dose of cisplatin and euthanized days later. However, this high dose cisplatin model does not reflect how most patients are treated with cisplatin in the clinic. To identify potential new therapeutic targets, we performed in vivo studies characterizing a clinically relevant repeated low-dose cisplatin ( RLDC) model, developed by the Siskind Lab and others, and found failed repair proximal tubule epithelial cells that have undergone a partial epithelial to mesenchymal transition (EMT), increased number of resident M2-like macrophages (MΦ), accumulation of myofibroblasts, loss of tubular brush border and fibrosis in the kidney. Zinc-finger E-box binding homeobox 1 (ZEB1) is a transcription factor known for its role in driving EMT as well as the activation and polarization of MΦ to an M2-like state. Data indicate that ZEB1 expression is upregulated in injured kidneys following RLDC treatment and other kidney injury models, correlating with enhanced EMT markers and increased macrophages. We hypothesize that ZEB1 drives RLDC-induced nephrotoxicity by mediating EMT in proximal tubule cells (PTCs) and activation of M2-like MΦs. Male and Female 8-week-old C57BL/6 mice with global partial ZEB1 knockout (ZEB1+/-) and littermate wild-type (WT) controls were subjected to weekly cisplatin (7 mg/kg) or vehicle control dosing for 4 weeks. Following the final cisplatin injection, markers of kidney function (BUN) and injury (KIM-1) were measured. Analysis of kidney immune cells was performed via flow cytometry and immunohistochemistry, EMT markers (vimentin, claudin-1), tubular brush border, fibrosis ( col1a1, TGF-b, a-SMA) were assessed by Western analysis and immunohistochemistry staining of kidney sections. Statistical Analysis was performed using Two-Way-ANOVA. A p-value of less than 0.05 was considered statistically significant. Western blot analysis confirmed reduced ZEB1 expression in ZEB1+/- mice compared to WT. ZEB1+/- mice were significantly protected from RLDC-induced kidney injury and progression to CKD as compared to WT control mice. PAS staining revealed ZEB1+/- reduced cisplatin induced loss of tubular brush border. BUN and KIM-1 were lower in ZEB1+/- mice as compared to WT control following RLDC as were kidney CD206+ M2-like MΦ. ZEB1+/- mice has lower expression of kidney fibrotic markers ( col1a1, TGF-b, a-SMA), following RLDC as compared to WT control mice. These findings suggest ZEB1 as a critical mediator of cisplatin-induced renal pathology, highlighting its role in macrophage activation and fibrosis progression. Overall, these data demonstrate that partial-global knockout of ZEB1 protects against cisplatin-induced kidney injury, EMT, macrophage infiltration, function and fibrosis in the RLDC model. These data highlight that ZEB1 may be a viable therapeutic target to prevent AKI progression to CKD in patients receiving cisplatin. Future studies will focus on cell-type-specific ZEB1 deletion and incorporation of cancer in the RLDC model in order to gain mechanistic insight to increase translational relevance. This abstract was presented at the American Physiology Summit 2026 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.
Sanchez et al. (Fri,) studied this question.