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Abstract: FR-PO359

Vascularization of iPSC-Kidney Organoids In Vitro Is Improved by Co-Culturing With Macrophages

Session Information

Category: Development‚ Stem Cells‚ and Regenerative Medicine

  • 500 Development‚ Stem Cells‚ and Regenerative Medicine

Authors

  • Kiyan, Yulia, Medizinische Hochschule Hannover, Hannover, Niedersachsen, Germany
  • Chernobrivaia, Ekaterina, Medizinische Hochschule Hannover, Hannover, Niedersachsen, Germany
  • Lachmann, Nico, Medizinische Hochschule Hannover, Hannover, Niedersachsen, Germany
  • Haller, Hermann, Medizinische Hochschule Hannover, Hannover, Niedersachsen, Germany
Background

Induced pluripotent stem cells (iPSC) - derived derived kidney organoids represent an attractive model for studying kidney development, disease mechanisms and drug response in vitro. Despite the progress achieved in the deciphering the developmental program of the kidney and differentiating iPSC to kidney organoids in vitro, our knowledge of the early stages of vascularization is limited. A major limitation is the lack of proper microvascular system to study the growth and development of iPSC organoids. Secondly, during the embryonic kidney development in vivo macrophages play an important role in vascularization. We have investigated the role of macrophages in vascular development using iPSC and a novel angiogenesis-on-chip model.

Methods

We have used co-culture of organoids and human iPSC-derived macrophages in microfluidic environment. We generated reporter iPSC cell lines expressing secreted Gaussia luciferase under control of CD31-promoter to monitor endothelial differentiation, 3D confocal microscopy, RNA sequencing and biochemical assays.

Results

Differentiation of iPSC-derived endothelial cells and endothelial-specific function such as permeability, development of glycocalyx, and permeability are significantly imporved by microfluidity conditions. In the presence of macrophages the number of endothelial cells is significantly increased. Furthermore, co-culture with macrophages induced lumen formation and capillary capillary growth. Formed capillary show directed growth towards the glomeruli-like nephrin-positive cell clusters and tend to interconnect developing neighboring organoids. The analysis of endothelial cells transcriptome shows advanced differentiation pattern in the presence of macrophages in comparison to the organoids in monoculture.

Conclusion

In summary, we firstly demonstrate that co-culturing developing iPSC-kidney organoids with human iPSC-macrophages promotes endothelial differentiation and induces capillary formation. Macrophages may directly or indirectly contribute to the early vascularization in organoids and can improve organoid-derived renal tissue generation.

Funding

  • Private Foundation Support