Renal Subcapsular Transplantation of PSC-Derived Kidney Organoids Induces Neo-vasculogenesis and Significant Glomerular and Tubular Maturation In Vivo

Abstract

SummaryHuman pluripotent stem cell (hPSC)-derived kidney organoids may facilitate disease modeling and the generation of tissue for renal replacement. Long-term application, however, will require transferability between hPSC lines and significant improvements in organ maturation. A key question is whether time or a patent vasculature is required for ongoing morphogenesis. Here, we show that hPSC-derived kidney organoids, derived in fully defined medium conditions and in the absence of any exogenous vascular endothelial growth factor, develop host-derived vascularization. In vivo imaging of organoids under the kidney capsule confirms functional glomerular perfusion as well as connection to pre-existing vascular networks in the organoids. Wide-field electron microscopy demonstrates that transplantation results in formation of a glomerular basement membrane, fenestrated endothelial cells, and podocyte foot processes. Furthermore, compared with non-transplanted organoids, polarization and segmental specialization of tubular epithelium are observed. These data demonstrate that functional vascularization is required for progressive morphogenesis of human kidney organoids.

Bioprinted pluripotent stem cell-derived kidney organoids provide opportunities for high content screening

“…To evaluate how effectively this can be performed, organoids were bioprinted using CRISPR/Cas9 geneedited reporter iPSCs. The MAFB mTagBFP2 reporter line has been previously used to monitor commitment to a podocyte lineage, allowing the visualisation of glomeruli in live organoids in vitro 17 and after organoid transplantation 18 . Organoids were bioprinted onto Transwells (1 x Figure 2).…”

Kidney‐in‐a‐lymph node: A novel organogenesis assay to model human renal development and test nephron progenitor cell fates

“…Indeed, our experience suggests long-term retention of the glomeruli while the renal tubules (especially the distal segments) are progressively lost. This phenomenon is not due to fibrosis or the conversion of the LN into a fibrotic environment, as suggested by staining for Erasmus University Rotterdam-Thymic Reticulum (ER-TR7), CD44, and platelet-derived growth factor receptor beta (PDGFR-β; Figure S4), which are expressed in kidney during development and/or adult life (Crisi, Marconi, Rockwell, Braden, & Campfield, 2009;Floege et al, 1997;Tsujie et al, 2000), and overexpressed during renal disease (Floege, Eitner, & Alpers, 2008;Kirimca, Sarioglu, Camsari, & Kavukcu, 2001;Roy-Chaudhury et al, 1996;Wagrowska-Danilewicz & Danilewicz, 2002). The precise mechanism of tubular loss in our ectopic human kidney grafts remains unknown.…”

“…However, animal transplantation is often needed to supply organoid cultures with a vascular system and obtain fully mature nephrons to be used in putative medical applications (Hariharan, Kurtz, & Schmidt-Ott, 2015). Renal subcapsular transplantation of kidney organoids has been exploited to induce neo-vasculogenesis (van den Berg et al, 2018), but this approach suffers from poor clinical translatability as the inflammatory and fibrotic milieu of a chronically injured kidney might not support the engraftment, survival, and function of the transplanted cells. In addition, clinical progress in renal subcapsular transplantation has lagged behind other techniques due to the inelastic and tight nature of the human renal subcapsular space (Sakata, Yoshimatsu, & Kodama, 2018).…”

From organoids to transplantable artificial kidneys

“…Interestingly, most endothelial cells in the glomeruli in the transplantation experiments were derived from the host animals rather than from the transplanted iPSCs [20,22]. In contrast, another group detected some integration of Higher-order kidney hiPSC-derived endothelial cells upon transplantation [23]. Further studies are needed to determine the relative contributions of the donor-and host-derived vasculatures to the transplanted kidney organoids.…”