PMC

hiPSC-derived nephron sheets reproducibly contain kidney structures and show high number of glomerular structures. A Immunofluorescence analysis for glomerular structures (NPHS1, NPHS2), endothelium (CD31), proximal tubule (LTL, CUBN), distal tubular and collecting duct structures (ECAD) in whole mount nephron sheets, and stromal cells (MEIS1/2/3, PDGFRα/β) in cryosections using LUMC0072, LUMC0020 and iPSC-MAFB (representative images from 3 independent experiments). B Immunofluorescent 3-dimensional overview showing distribution of NPHS1, CD31 and LTL in bisected hiPSC-derived nephron sheet. C Diameter of hiPSC-derived nephron sheets using an 18 mm template in multiple hiPSC lines. (LUMC0072: 32 nephron sheets in 11 independent experiments, LUMC0020: 5 nephron sheets in 3 independent experiments, iPSC-MAFB: 11 nephron sheets in 6 independent experiments). D Volume of individual glomerular structures (µm³) of organoids and nephron sheets. Each dot represents the volume of a single glomerular structure determined in LUMC0072: 7 organoids from 4 independent experiments and 3 nephron sheets from 3 independent experiments; LUMC0020: 6 organoids in 6 independent experiments and 3 nephron sheets in 3 independent experiments; iPSC-MAFB: 4 organoids in 4 independent experiments and 3 nephron sheets in 3 independent experiments. Bar displays average. E Number of glomerular structures in organoids and nephron sheets. Total glomerular number was determined in LUMC0072: 4 organoids from 4 independent experiments and 4 nephron sheets from 4 independent experiments; LUMC0020: 5 organoids in 5 independent experiments and 3 nephron sheets in 3 independent experiments; iPSC-MAFB: 3 organoids in 3 independent experiments and 3 nephron sheets in 3 independent experiments. Bar displays average

Upscaling of nephron sheets to a diameter of at least 4 cm. A Image of large-scale nephron sheet of 12.6 cm² made with a 4 cm diameter cover template (iPSC-MAFB). B, C Immunofluorescence analysis of the entire nephron sheet shows presence and equal distribution of kidney tubular structures stained for proximal (LTL, B) and distal (ECAD, C) markers. D Section of the large nephron sheet highlights the distribution of tubular structures stained for LTL and ECAD combined. E Detection of nephron structures after immunofluorescence staining for glomerular structures (NPHS1), proximal tubules (LTL), and distal tubules (ECAD)

Quantitative analysis of N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) in different nephron fractions through the stop-flow technique. A: PAH concentrations in consecutive urine fractions were analyzed to identify the fractions representing the proximal part of the nephron. B: kallikrein activity in consecutive urine fractions was analyzed to identify the fractions representing the distal part of the nephron. C: Ac-SDKP adjusted by water reabsorption along the nephron. Greatest amounts of Ac-SDKP are observed in the distal portion of the nephron, and smallest amounts are found in the proximal part of the nephron. Bottom curve (open squares) represents the Ac-SDKP-to-inulin ratio under infusion of the prolyl oligopeptidase enzyme inhibitor (POP inh) KYP-2047. Last 2 fractions in all panels represent the amounts of free flow (n = 7). *P < 0.01, distal nephron vs. proximal nephron. #P < 0.05, vehicle vs. POP inhibitor.