For the first time in the history of medical science, scientists from the University of Manchester have been able to produce functioning human kidney tissue inside a living organism. For the medical community and for ailing patients, this means more effective treatments for kidney disease.
The study, which was published in the journal Stem Cell Reports, was led by Professors and researchers Sue Kimber and Adrian Wolf.
The team were able to grow kidney glomeruli from embryonic stem cells in a laboratory. Kidney glomeruli serve an important function in the filtration of blood and subsequent production of urine. In fact, these microscopic parts of the kidney serve within a network as the first stage in the filtering process. These tiny capillaries grew inside of a plastic culture dish containing a nutrient broth full of molecules to promote kidney development.
Once the kidney glomeruli grew and matured, they were combined with what researchers are calling ‘a gel like substance’. It acted as natural connective tissue which formed a tiny clump and was injected into mice.
The result: mini, human-like kidneys.
Three months after the initial injection, the structures that actually produce urine as a process of removing waste from the blood had formed. The structures, called nephrons, contained most of the parts present in human nephrons and tiny human blood vessels had formed which were nourishing the new kidney structures. But, these new kidneys aren’t yet fully functioning. They lack an essential artery that pumps more blood into them.
Nonetheless, the system was successfully filtering, producing and excreting urine.
“We have proved beyond any doubt these structures function as kidney cells by filtering blood and producing urine – though we can’t yet say what percentage of function exists,” said Professor Kimber.
It’s a stunning advancement in biological and medical science but there is still a ways to go before scientists will be able to grow functioning kidneys to replace failing kidneys in patients. Where human kidneys have about one million glomeruli in their kidneys, this mouse-grown structure contained only a few hundred.
The study was supported by The University of Manchester’s School of Biological Sciences, Manchester Regenerative Medicine Network (MaRM) and Kidneys for Life and funded by The Medical Research Council and Kidney Research UK. It’s clear why: There are over 100,000 people on the kidney transplant waiting list. The waiting list has doubled in size over the last 10 years and people are waiting 5-10 years for a transplant. While hundreds of thousands of people are organ donors, less than 1 percent of deaths offer organs that can be used.
But it’s not just people on transplant waiting lists that are suffering. When you include dialysis, the number grows exponentially.
“Worldwide, 2 million people are being treated with dialysis or transplantation for kidney failure, and sadly another 2 million die each year, unable to access these treatments,” Woolf said in a press release.
With such a growing need for kidneys and very limited availability, it’s paramount that scientists work to find an alternative. This is a great first step and could potentially save the lives of millions.
“… We are tremendously excited by this discovery — we feel it is a big research milestone which may one day help patients,” Woolf said.