Kidney Week

Abstract: SA-PO079

Macrophage Infusion Rescues Cisplatin (CP)-Induced AKI

Session Information

• AKI: Inflammation and Cell Cycle
  October 26, 2024 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Acute Kidney Injury

• 103 AKI: Mechanisms

Authors

• Guo, Xiaojia, Yale University School of Medicine, New Haven, Connecticut, United States

Xiaojia Guo, PhD

• Xu, Leyuan, Yale University School of Medicine, New Haven, Connecticut, United States

Leyuan Xu, PhD

• Velazquez, Heino, Yale University School of Medicine, New Haven, Connecticut, United States

Heino Velazquez, PhD

• Chen, Tian-Min, Yale University School of Medicine, New Haven, Connecticut, United States

Tian-Min Chen

• Safirstein, Robert L., Yale University School of Medicine, New Haven, Connecticut, United States

Robert L. Safirstein, MD

• Desir, Gary V., Yale University School of Medicine, New Haven, Connecticut, United States

Gary V. Desir, MD

Background

CP induces AKI, and repeated doses leads to chronic kidney disease (CKD) in humans. Previously, we produced a mouse model using two doses of CP two weeks apart that recapitulates the features of CP-AKI and CP-CKD in humans. Here, we employ 13 different KO mouse models to identify genes that play a critical role in kidney injury.

Methods

Single-cell RNA sequencing (scRNAseq) was performed on kidneys of wild-type (WT) mice 0, 1, 3, and 5 days (D) after 15 mg/Kg CP to identify the transcriptional response changes in major cell types during the induction of injury. These findings were confirmed by immunohistochemistry and quantitative reverse transcription polymerase chain reaction (RTqPCR). The course of AKI and CKD was then followed in KO mice. Bone marrow-derived macrophages (BMDM) were isolated from either WT or KO mice and injected into KO mice treated with cisplatin to identify protective genes.

Results

Plasma creatinine at D0, D1, D3, and D5 was 0.07±0.01, 0.08±0.09, 0.42±0.05, and 0.16±0.09 mg/dL, respectively, n=3, (p<0.005 for D3 by one way ANOVA). The % of injured proximal tubule cells (PT) of D0, D1, D3, and D5 were 0.15, 0.44, 4.36, and 2.93 respectively; Neutrophils increased from 0.04% at D0 to 0.89% at D3 and reduced to 0.31% at D5. Macrophage and T cell plateaued at D3. ScRNAseq and whole kidney RTqPCR showed CP increased Cxcl1, p21, Tlr2, Sox9 in injured PT; Apobec1, Tlr4, Tlr2, RIPK3, Ccl2, Ccr2, Cxcl1, p21 in macrophages; and Ppif, Lcn2 in neutrophils and reduced RNLS in whole kidney. Of 13 KOs of these 12 genes plus double KO of Tlr2 and Tlr4, only Apobec1 and RNLS showed profound effects on the course of AKI/CKD as none of the Apobec1 KOs survived the initial dose of CP, and Rnls KOs developed more severe CKD. As Apobec1 and Rnls were expressed by macrophages, we injected undifferentiated WT BMDM in each KO mouse. WT macrophage infusion reduced kidney injury in Apobec1 KO (BUN 53.81±3.52 vs 72.74±1.4 mg/dL, n=4, p<0.01) and Rnls KO mice (49.16±4.39 vs 68.57±2.89 mg/dL, n=4, p<0.01) as compared to mice infused with KO BMDM and reduced the expression of KIM-1 and Ccl2 in the kidneys of these mice.

Conclusion

Our results indicate that Apobec1 and RNLS are key cargo components within the macrophages and are crucial to the outcome of the injury and suggest that macrophages can be a potent delivery system of these molecules.

Funding

• NIDDK Support