Abstract: TH-PO0530
Tonicity Matures the Collecting Ducts of the Kidneys
Session Information
- Development, Stem Cells, and Regenerative Medicine
November 06, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Development, Stem Cells, and Regenerative Medicine
- 600 Development, Stem Cells, and Regenerative Medicine
Authors
- Inoue, Daisuke, Kumamoto University, Institutes of Molecular Embryology and Genetics, Kumamoto, Japan
- Izumi, Yuichiro, Kumamoto University, Department of Nephrology, Kumamoto, Japan
- Nishinakamura, Ryuichi, Kumamoto University, Institutes of Molecular Embryology and Genetics, Kumamoto, Japan
Background
Organ maturation is a fundamental question in biology. Building mature organoids is also essential for regenerative medicine. We have developed kidney organoids induced from mouse and human pluripotent stem cells (Taguchi et al. Cell Stem Cell 2014; Taguchi and Nishinakamura. Cell Stem Cell 2017; Tanigawa et al. Nat. Commun. 2022). However, these kidney organoids are still immature. Previous studies have reported that endocrine hormones, shear stress, and metabolic substrates promote kidney maturation (Uchimura et al. Cell Reports 2020; Homan et al. Nat. Methods 2019; Wang et al. Cell Stem Cell 2022). Our motivation here was to uncover a new maturation program.
Methods
We hypothesized that high tonicity, one of the unique characteristics of the kidney medulla, would mature the collecting ducts (CDs). We cultured mouse and human ureteric buds, which are the precursors of CDs, at high tonicity by adding sodium chloride to the culture media, and investigated their maturity. For disease modeling, we established iPSC lines harboring one of the mutations of nephrogenic diabetes insipidus (NDI) and induced mature human CD organoids from these cell lines.
Results
Mouse CD organoids matured at high tonicity in terms of morphology, genetic profile, and physiological function. Our scRNA-seq analysis revealed that a broad spectrum of genes, including transcription factors, signaling molecules, and transporters, were upregulated by tonicity and that these genes accounted for approximately half of the maturation markers of the medullary CDs. This process was mainly dependent on the transcription factor NFAT5 (nuclear factor of activated T cells 5). Based on these findings, we have established a maturation protocol for human CD organoids. Human CDs also morphologically and transcriptionally matured and acquired vasopressin responsiveness at high tonicity. Furthermore, the mature CD organoids induced from iPSC lines with a mutation that causes NDI lost their responsiveness to vasopressin, whereas the control organoids responded to vasopressin with AQP2 clearly localized on the apical membrane.
Conclusion
High tonicity is a driving force for mammalian kidney maturation, not only for urine concentration. Our study uncovers a novel principle of organ maturation triggered by environmental cues and offers a promising way to maximize the potential of organoids for disease modeling and therapy development.
Funding
- Government Support – Non-U.S.