Vascularized and Complex Organ Buds from Diverse Tissues via Mesenchymal Cell-Driven Condensation
Self-Organization of Functional and Vascularized Kidney via In-Vitro-Grown 3D Organ Bud Transplantation
(A) Macroscopic observation of transplanted in-vitro-grown kidney buds showing perfusion and sophistication of reconstituted blood vessels. The dotted area indicates the transplants.
(B) Intravital tracking of kidney buds showing in vivo dynamics of kidney development.
(C) Self-organization of glomerular structures from kidney bud generated from three distinct fluorescent embryonic mice after 14 days. Bar, 50 μm.
(D) mCD31-647 infusion study demonstrating the formation of multi-colored labeled, glomerular-like tissue with capillaries.
(E) Generation of functional nephrons from transplanted kidney buds at 28 days after transplantation under a cranial window. Tissues resembling glomeruli or tubular structures barely developed from the E13.5-dispersed cell transplant (right lower panel). Red, dextran; green, GFPs; blue, mouse-specific CD31; unlabeled, HUVECs and hMSCs.
(F) Comparison of kidney developmental gene signatures among in-vitro-derived kidney buds at 2 and 4 weeks after transplantation and primary kidneys (E13.5, 0 day [P0] and 8 weeks [P8wk] after birth).
(G) Intravital visualization of the renal functions of the generated glomeruli after 21 days of transplantation, including initial blood perfusion (left), primary filtration into Bowman’s space (middle), and urinary outflow into collecting systems (right). Red, mouse GFP; green, Lucifer Yellow; blue, mouse-specific CD31; unlabeled, HUVECs and hMSCs. Yellow arrowhead, Lucifer Yellow; white arrowhead, Lucifer-Yellow-negative endothelial cells.
(H) Histological analysis of reconstituted tissues explanted at 21 days. Immunostaining for LTA, nephrin, WT1, GFP, and laminin is shown in each panel. Bars, 100 μm.
(I) Electron microscopy of kidney bud transplants at 21 days. GL; glomerulus; PT, proximal tubule; P, podocyte; E, capillary endothelium; R, red blood cell; M, mesangial cell; bm, basement membrane; fp, foot processes; mv, microvilli; ly, lysosome; mt, mitochondria.