Generation of Functioning Nephrons by Implanting Human Pluripotent Stem Cell-Derived Kidney Progenitors

Abstract

Summary: Human pluripotent stem cells (hPSCs) hold great promise for understanding kidney development and disease. We reproducibly differentiated three genetically distinct wild-type hPSC lines to kidney precursors that underwent rudimentary morphogenesis in vitro. They expressed nephron and collecting duct lineage marker genes, several of which are mutated in human kidney disease. Lentiviral-transduced hPSCs expressing reporter genes differentiated similarly to controls in vitro. Kidney progenitors were subcutaneously implanted into immunodeficient mice. By 12 weeks, they formed organ-like masses detectable by bioluminescence imaging. Implants included perfused glomeruli containing human capillaries, podocytes with regions of mature basement membrane, and mesangial cells. After intravenous injection of fluorescent low-molecular-weight dextran, signal was detected in tubules, demonstrating uptake from glomerular filtrate. Thus, we have developed methods to trace hPSC-derived kidney precursors that formed functioning nephrons in vivo. These advances beyond in vitro culture are critical steps toward using hPSCs to model and treat kidney diseases. : Kimber and colleagues show that pluripotent stem cell-derived kidney progenitors implanted subcutaneously generate vascularized glomeruli including podocytes with slit diaphragms and mature glomerular basement membranes indicative of functioning glomeruli. Human cells contributed to the vasculature, and the glomeruli were able to filter low-molecular-weight dextran injected intravenously, which appeared in some tubules. Keywords: human embryonic stem cells, kidney, nephron, glomerulus, lentivirus, kidney progenitors, metanephric mesenchyme, ureteric epithelium, vascularization, cell therapy