Kidney Week

Abstract: TH-PO216

Validation of an Organoid Model for CKD-Related Vasculature Changes and Vascular Calcifications Development

Session Information

• Hypertension and CVD: Basic Research Findings
  October 24, 2024 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Hypertension and CVD

• 1601 Hypertension and CVD: Basic

Authors

• Bernardor, Julie, Laboratoire de Physiomédecine Moléculaire (LP2M), UMR 7370 CNRS, Nice, France

Julie Bernardor, MD, PhD

• Simonin, Justine, Laboratoire de Physiomédecine Moléculaire (LP2M), UMR 7370 CNRS, Nice, France

Justine Simonin

• Larché, Elise, Laboratoire de Physiomédecine Moléculaire (LP2M), UMR 7370 CNRS, Nice, France

Elise Larché

• Blin, Claudine, Laboratoire de Physiomédecine Moléculaire (LP2M), UMR 7370 CNRS, Nice, France

Claudine Blin, PhD

• Caillot, Zakariya, Laboratoire de Physiomédecine Moléculaire (LP2M), UMR 7370 CNRS, Nice, France

Zakariya Caillot, MSc

• Bartosova, Maria, University Hospital Heidelberg, Heidelberg, Germany

Maria Bartosova, PhD

• Schmitt, Claus Peter, University Hospital Heidelberg, Heidelberg, Germany

Claus Peter Schmitt, MD, PhD

• Rouleau, Matthieu, Laboratoire de Physiomédecine Moléculaire (LP2M), UMR 7370 CNRS, Nice, France

Matthieu Rouleau, PhD

Group or Team Name

• Ostéoimmunologie, Niches et Inflammation.

Background

Chronic kidney disease (CKD) is associated with high cardiovascular risk, mainly due to vascular calcifications (VC). Mortality rate is high, due to a significant increase of the risk of cardiovascular diseases, related to vascular calcifications. Current understanding indicates that vascular calcifications in CKD involve complex mechanisms, including gene expression changes and endothelial dysfunction. To elucidate complex pathomechanisms leading to VC development, there is a critical need for an in vitro model reflecting CKD induced vascular disease.

Methods

We developed a vascular organoid model using human-induced pluripotent stem cells (hiPSCs). Organoids were formed through differentiation into mesodermal and then vascular cells, followed by embedding in a 3D-collagen matrix. Organoids were maintained in culture for over 30 days. We then induced CKD with pro-calcifying (inorganic phosphate), inflammatory (IL-1β, IL-6, TNF-α), and uremic toxin (indoxyl sulfate) treatments. Analyses included immunofluorescence for vascular markers (CD31, CD140b, αSMA, Collagen IV); RT-qPCR for gene expression; and Alizarin Red staining/ Osteosense assays for calcium deposits.

Results

The vascular organoids developed endothelial cells surrounded by pericytes and smooth muscle cells within a collagen IV-rich matrix. Cytokine treatments resulted in reduced density of endothelial and smooth muscle cells, particularly with IL-6 and TNF-α. Indoxyl sulfate also decreased vascular density. Treatment with inorganic phosphate led to decreased vascular density, increased vessel diameter, and calcium deposits, alongside with modified osteoblastic gene expression (RUNX2; Sp7, APLP, Spp1).

Conclusion

We successfully established a vascular organoid model that replicates key features of human vasculature networks and CKD induced changes. It now provides a valuable tool for studying CKD-related pathomechanisms and testing putative therapeutic interventions. Future research using this model should employ single-nucleus RNA sequencing (snRNA-seq), spatial transcriptomics, and CRISPR-Cas9 analyses to further investigate the CKD-related cardiovascular disease.