Journal: Npj Biomedical Innovations
Article Title: Engineering scalable vascularized kidney organoids for in vivo glomerular filtration with human endothelial integration
doi: 10.1038/s44385-025-00063-5
Figure Lengend Snippet: A Vessel sprouts in polarized podocyte clusters with CD146+ capillary network supported by MEIS1/2/3+ stromal cells in day 21 STR organoids (left set of two images) compared to the podocyte clusters of day 21 control static organoids (right set of four images). White arrows in the STR images indicate the vascularized glomeruli surrounded by polarized podocytes. Scale bars of STR images represent 100 μm and 10 μm (zoomed STR image), respectively. Rectangular white dashed lines point out the zoomed images of non-vascularized podocyte clusters of the static organoid. Scale bars of static organoid images represent 100 μm. B 3D surface reconstruction of CD146+ capillary network and surrounding PODXL+ podocyte clusters as vascularized glomerular components. Z-stack images were acquired at a step size of 2 μm. The scale bar represents 30 μm. C Transmission electron microscopy images show multiple vascular lumens (left image) and accompanying podocyte foot processes around the vascular lumen (right image) within organoid glomerular structures on day 35. The asterisk indicates the nucleus of the podocyte surrounding the vascular lumen, while the arrowheads mark podocyte foot processes. Black scale bars at the corners: 2 μm. D Percentages of vascularized podocyte clusters containing CD146 endothelial surface in STR versus static organoids via 3D surface reconstruction by machine learning. n = 3 static and n = 9 STR organoids from 3 independent batches differentiated from BJFF.6 or HUES62 cells. E ACTA2+ mesangial-like cells surrounded by polarized PODXL+ podocytes in Bowman’s space of day 35 STR and static organoids. STR organoids were generated by the transfer of the same-batch static organoids into STR wells on day 14 of differentiation. The graph represents the percentage of organoids containing ACTA2+ cells ( n = 5 static and n = 6 STR organoids from 2 independent batches differentiated from H9 or HUES62 cells). F Upregulation of certain GO terms associated with extracellular matrix organization, cell adhesion, and migration in day 35 STR organoids compared to static organoids. “Regulation of cell migration”, “Positive regulation of cell adhesion”, “Regulation of cell adhesion”, and “Extracellular matrix organization” terms constitute GO biological processes while “Extracellular matrix”, “Collagen-containing extracellular matrix”, “Actin-based cell projection”, and “Basement membrane”, “Collagen network”, and “Basement membrane collagen trimer” terms can be classified as GO cellular components, and “Assembly of collagen fibrils and other multimeric structures” is a part of Reactome pathways. G Inhibition of glomerular vascularization of STR organoids by the application of α2β1 integrin inhibitor, BTT3033 (stock concentration of 10 mM), with a final concentration of 1 μM for 7 or 18 days, in contrast to the control vehicle-treated organoids. The white arrows in the confocal microscopy images indicate the vascularized glomeruli surrounded by polarized podocytes. The scale bars represent 100 μm. H 3D surface reconstruction of CD146+ capillary network and surrounding PODXL+ podocyte clusters as vascularized glomerular surfaces in vehicle- and BTT3033-treated organoids. Z-stack images were acquired at a step size of 2 μm. The scale bar represents 50 μm. Y-axes of graphs represent two parameters: the percentage of vascularized podocyte clusters and the volume percent ratio of CD146+ vascular surface in these podocyte clusters to the whole PODXL+ podocyte surface, respectively ( n = 7). Asterisks in the bar graphs ( D , E , H ) indicate p values derived from two-tailed unpaired t-tests. Means ± SEM. (* p ≤ 0.05, ** p ≤ 0.01, *** p ≤ 0.001).
Article Snippet: Collagen IV α1 , Rockland , 600-401-106S, RRID: AB_11183330.
Techniques: Control, Transmission Assay, Electron Microscopy, Generated, Migration, Membrane, Inhibition, Concentration Assay, Confocal Microscopy, Derivative Assay, Two Tailed Test