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Updated: Sep 5, 2025
Guided Differentiation of Mature Kidney Podocytes from Human Induced Pluripotent Stem Cells Under Chemically Defined Conditions
Published on: July 2, 2020
Single-cell analysis highlights differences in druggable pathways underlying adaptive or fibrotic kidney regeneration
Michael S Balzer1,2, Tomohito Doke1,2, Ya-Wen Yang1,2
1Renal, Electrolyte, and Hypertension Division, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
Abstract:
The kidney has tremendous capacity to repair after acute injury, however, pathways guiding adaptive and fibrotic repair are poorly understood. We developed a model of adaptive and fibrotic kidney regeneration by titrating ischemic injury dose. We performed detailed biochemical and histological analysis and profiled transcriptomic changes at bulk and single-cell level (> 110,000 cells) over time. Our analysis highlights kidney proximal tubule cells as key susceptible cells to injury. Adaptive proximal tubule repair correlated with fatty acid oxidation and oxidative phosphorylation. We identify a specific maladaptive/profibrotic proximal tubule cluster after long ischemia, which expresses proinflammatory and profibrotic cytokines and myeloid cell chemotactic factors. Druggability analysis highlights pyroptosis/ferroptosis as vulnerable pathways in these profibrotic cells. Pharmacological targeting of pyroptosis/ferroptosis in vivo pushed cells towards adaptive repair and ameliorates fibrosis. In summary, our single-cell analysis defines key differences in adaptive and fibrotic repair and identifies druggable pathways for pharmacological intervention to prevent kidney fibrosis.
Insights
Kidney repair pathways after injury are unclear. This study identifies key cell types and molecular targets, like pyroptosis and ferroptosis, to promote adaptive repair and prevent kidney fibrosis.
Area of Science:
- Nephrology
- Regenerative Medicine
- Molecular Biology
Background:
- Kidney injury can lead to either adaptive repair or fibrosis, but the underlying mechanisms are not fully understood.
- Identifying the specific cellular and molecular pathways that dictate the outcome of kidney repair is crucial for developing effective treatments.
Purpose of the Study:
- To elucidate the pathways governing adaptive and fibrotic kidney repair following acute ischemic injury.
- To identify specific cell populations and molecular targets involved in maladaptive kidney repair.
- To explore the therapeutic potential of targeting identified pathways to promote kidney regeneration and prevent fibrosis.
Main Methods:
- Development of a rodent model of kidney injury by titrating ischemic dose.
- Comprehensive biochemical, histological, and transcriptomic analyses (bulk and single-cell RNA sequencing) over time.
- In vivo pharmacological targeting of identified vulnerable pathways in profibrotic cells.
Main Results:
- Proximal tubule cells are identified as key targets of ischemic injury.
- Adaptive repair is associated with fatty acid oxidation and oxidative phosphorylation.
- A distinct profibrotic proximal tubule cell cluster emerges after prolonged ischemia, expressing pro-inflammatory and pro-fibrotic factors.
- Targeting pyroptosis and ferroptosis pathways in vivo promotes adaptive repair and reduces kidney fibrosis.
Conclusions:
- Single-cell transcriptomic analysis reveals distinct cellular mechanisms underlying adaptive versus fibrotic kidney repair.
- Pyroptosis and ferroptosis pathways represent druggable targets for preventing kidney fibrosis.
- Pharmacological intervention targeting these pathways offers a promising strategy for promoting kidney regeneration.
