Abstract: PO0333
Distinct Spatiotemporal Dynamics of Damaged Proximal Tubular Epithelial Cells After Mild and Severe AKI in Mice
Session Information
- AKI: Mechanisms of Injury
November 04, 2021 | Location: On-Demand, Virtual Only
Abstract Time: 10:00 AM - 12:00 PM
Category: Acute Kidney Injury
- 103 AKI: Mechanisms
Authors
- Ide, Shintaro, Duke University School of Medicine, Durham, North Carolina, United States
- Kobayashi, Yoshihiko, Duke University School of Medicine, Durham, North Carolina, United States
- Ide, Kana, Duke University School of Medicine, Durham, North Carolina, United States
- Strausser, Sarah A., Duke University School of Medicine, Durham, North Carolina, United States
- Herbek, Savannah, Duke University School of Medicine, Durham, North Carolina, United States
- O'Brien, Lori L., University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, United States
- Crowley, Steven D., Duke University School of Medicine, Durham, North Carolina, United States
- Barisoni, Laura, Duke University School of Medicine, Durham, North Carolina, United States
- Tata, Aleksandra, Duke University School of Medicine, Durham, North Carolina, United States
- Tata, Purushothama rao, Duke University School of Medicine, Durham, North Carolina, United States
- Souma, Tomokazu, Duke University School of Medicine, Durham, North Carolina, United States
Background
Clinical and preclinical studies revealed that damage to proximal tubular (PT) epithelial cells after severe acute kidney injury (AKI) is a critical mechanism underlying the development of chronic kidney disease (CKD). Recent advancements of single-cell RNA sequencing (scRNA-seq) approach identified that PT cells adopt heterogeneous molecular states after injury and contribute to maladaptive repair. However, their cell fate after mild versus severe AKI remains poorly understood.
Methods
Single-cell transcriptomics and genetic fate-mapping approaches were used in a mouse model of unilateral ischemia-reperfusion injury (IRI) to investigate PT cell dynamics after short (20 min) and prolonged ischemia (30 min). For scRNA-seq analyses, we analyzed a total of 18,258 cells from the damaged kidneys harvested on 6 hours, and 1, 7, and 21 days after 30 min ischemia and the homeostatic normal kidneys. We used Seurat’s integration and label transfer to create the integrated dataset. To infer the dynamic cellular process during injury and repair, we used two computational tools (Monocle 3 and Velocyto).
Results
Our single-cell mouse atlas of maladaptive repair shows that PT cells develop a molecularly distinct, pro-inflammatory state following injury. These cells are characterized by reduced expression of homeostatic genes (ex. Lrp2, Slc34a1) and enrichment of genes associated with kidney development (ex. Sox9, Cdh6) and kidney injury (ex. Vcam1, Havcr1). Gene ontology analysis of these cells revealed high enrichment of pro-inflammatory signaling. Our genetic fate-mapping using a Sox9IRES-CreERT2; Rosa26-tdTomato mouse line showed these inflammatory PT cells transiently appear after short ischemia and return to their original state without inducing fibrosis. However, they accumulate and contribute to persistent inflammation after prolonged ischemia.
Conclusion
Our single-cell transcriptomic and genetic fate-mapping approaches identify that the accumulation of inflammatory PT cells after severe injury underlies the maladaptive repair process. Future studies of how this pathologic cell state persists and contributes to inflammation will inform us to develop novel therapeutic approaches for AKI and its transition to CKD.
Funding
- NIDDK Support