KIDNEY TISSUE that effectively filters the blood and produces urine has been generated from human embryonic stem cells for the first time. Hailed as a major milestone in kidney disease research, scientists from the University of Manchester, Manchester, UK, hope the technique will lead to more successful management of the 64,000 people currently being treated for kidney failure.
To generate the kidney glomeruli in vitro, human embryonic stem cells were grown in culture medium to promote kidney development. The natural connective tissue that surrounds the in vivo kidney was created using a gel-like substance. Three months after injecting the generated cells in combined with the artificial connective tissue beneath the skin of mice, the team observed that functioning nephrons had formed, including most of the components present in human nephrons, including the Bowman’s capsule, Loop of Henle, and the proximal and distal tubules. In addition, the cells had developed a capillary blood supply for the new kidneys, linking to the vasculature of the mice.
“We have proved beyond any doubt these structure function as kidney cells by filtering blood and producing urine, though we can’t yet say what percentage of function exists,” explained research lead Prof Sue Kimber, University of Manchester. Due to the absence of a large artery and therefore lack of a rich blood supply, the function of the human kidney tissue in the mice did not match that of human kidneys; however, the team are now working with surgeons to place an artery in the organ to increase the blood supply.
Approximately 45,000 premature deaths occur every year in the UK due to chronic kidney disease, with around one in eight people in the UK expected to develop the disease. Prof Adrian Woolf, University of Manchester and Royal Manchester Children’s Hospital, Manchester, expressed hope for the future of kidney disease therapies following this study: “We are tremendously excited by this discovery; we feel it is a big research milestone which may one day help patients.”
Building on this proof-of-principle study, the researchers explained that much more work is needed to explore how the urine produced by these kidney filtration units can be removed from the body and how this technology can be applied to the management of patients with diseased kidneys.
