Kidney Week

Abstract: FR-PO992

Hypoxia Induces Metabolic Alterations in Kidney Organoids

Session Information

• CKD: Pathobiology - I
  November 04, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
  Abstract Time: 10:00 AM - 12:00 PM

Category: CKD (Non-Dialysis)

• 2203 CKD (Non-Dialysis): Mechanisms

Authors

• Minakawa, Akihiro, University of Michigan Division of Nephrology, Ann Arbor, Michigan, United States

Akihiro Minakawa,

• Fischer, Matthew, University of Michigan Division of Nephrology, Ann Arbor, Michigan, United States

Matthew Fischer,

• El Saghir, Jamal, University of Michigan Division of Nephrology, Ann Arbor, Michigan, United States

Jamal El Saghir,

• He, Chenchen, University of Michigan Division of Nephrology, Ann Arbor, Michigan, United States

Chenchen He,

• Vega-Warner, V., University of Michigan Division of Nephrology, Ann Arbor, Michigan, United States

V. Vega-Warner,

• Hartman, John R., University of Michigan Division of Nephrology, Ann Arbor, Michigan, United States

John R. Hartman,

• Eichinger, Felix H., University of Michigan Division of Nephrology, Ann Arbor, Michigan, United States

Felix H. Eichinger,

• Schaub, Jennifer A., University of Michigan Division of Nephrology, Ann Arbor, Michigan, United States

Jennifer A. Schaub,

• Pennathur, Subramaniam, University of Michigan Division of Nephrology, Ann Arbor, Michigan, United States

Subramaniam Pennathur,

• Kretzler, Matthias, University of Michigan Division of Nephrology, Ann Arbor, Michigan, United States

Matthias Kretzler,

• Harder, Jennifer L., University of Michigan Division of Nephrology, Ann Arbor, Michigan, United States

Jennifer L. Harder,

Background

Kidney hypoxia may contribute to development and progression of kidney disease, but the mechanism is difficult to model in vivo. The aim of this study was to demonstrate the relevance of a newly developed in vitro hypoxic kidney organoid model.

Methods

Kidney organoids containing multiple cell types and organ-specific architecture were generated from human pluripotent stem cells (PSCs) and placed in a hypoxia chamber filled with 1% O₂ for 3 and 24 hours. Samples were analyzed for alterations in gene expression of HIF1A and its known targets (qRT-PCR, ELISA of cell lysates and supernatant, IF), and in functional metabolites (LC-MS of ¹³C glucose flux) followed by transcriptional pathway analysis (TPA).

Results

Hypoxia induced nuclear accumulation of HIF1A, and increased transcription and/or protein levels of known HIF1A targets (VEGF and SLC2A1), glycolytic genes (HK1, HK2 and ENO1) and lactate synthesis. Genes related to Acetyl CoA synthesis (LDHA and PDK1) were suppressed. A flux analysis of glucose metabolism demonstrated that glycolysis increased, and oxidative phosphorylation decreased in organoids exposed to a hypoxic environment. TPA revealed Glycolysis, Sirtuin Signaling, Cell Cycle Control of Chromosomal and mitochondrial dysfunction as top canonical pathways, with HIF1A being the most significant upstream regulator.

Conclusion

Our hypoxic kidney organoid model successfully recapitulates key transcriptional, protein and metabolic alterations generated by hypoxic conditions. This novel in vitro model will facilitate investigations into hypoxia’s contribution to kidney cell dysfunction, especially in combination with other kidney cell stressors such as inflammation. In the future, a comparison of the hypoxic response of kidney organoid and human kidney cells at a single cell level may help to identify what cell type specific transcriptional alterations are associated with disease development related to hypoxia.

Funding

• Other NIH Support