Adult kidneys constantly grow, remodel themselves, study finds

July 2, 2014 by Christopher Vaughan
Adult kidneys constantly grow, remodel themselves, study finds
Contrary to long-held beliefs, a new study shows that kidneys have the capacity to regenerate themselves. Credit: Shutterstock

(Medical Xpress)—It was thought that kidney cells didn't reproduce much once the organ was fully formed, but new research shows that the kidneys are regenerating and repairing themselves throughout life.

Researchers at the Stanford Institute for Stem Cell Biology and Regenerative Medicine and the Sackler School of Medicine in Israel have shown how the kidneys constantly grow and have surprising ability to regenerate themselves, overturning decades of accepted wisdom that such regeneration didn't happen. It also opens a path toward new ways of repairing and even growing kidneys.

"These are basic findings that have direct implications for disease and kidney regeneration," says Yuval Rinkevich, PhD, the lead author of the paper and a postdoctoral scholar at the institute.

The findings were published online May 15 in Cell Reports.

It has long been thought that kidney cells didn't reproduce much once the organ was fully formed. The new research shows that the kidneys are regenerating and repairing themselves throughout life.

"This research tells us that the kidney is in no way a static organ," said Benjamin Dekel, MD, PhD, a senior author of the paper and associate professor of pediatrics at Sackler, as well as head of the Pediatric Stem Cell Research Institute at the Sheba Medical Center in Israel. "The kidney, incredibly, rejuvenates itself and continues to generate specialized all the time."

Irving Weissman, MD, professor of pathology and of developmental biology and director of the Stanford institute, is the other senior author.

The research, which was done in mice, also shows how the kidney regenerates itself. Instead of a single type of kidney stem cell that can replace any lost or damaged , slightly more specialized that reside in different segments of the kidney give rise to new cells within each type of kidney tissue.

Like a tree

"It's like a tree with branches in which each branch takes care of its own growth instead of being dependent on the trunk," Dekel said.

The scientists also showed that the decision these cells make to grow is made through the activation of a cellular pathway involving a protein called Wnt. Even though populations of kidney epithelial cells look the same, the most robust kidney-forming capacity can be traced back to precursor cells in which Wnt is activated and that can only grow into certain types of specialized kidney tissue, Rinkevich said. "The realization that Wnt signaling is responsible for the growth of new kidney tissue offers a therapeutic target to promote or restore the regenerative capacity of the kidneys," he said. "We may be able to turn on the Wnt pathway to generate new kidney-forming cells."

This finding will be important for scientists who attempt to create kidney parts in the lab, the researchers said.

However, they cautioned that such advances are not imminent. "To grow a whole kidney in the laboratory would be complicated because we would need to orchestrate the activities of many different kinds of precursor cells using just the right stimuli," Dekel says. "It's not like the blood and immune system, which can be reconstituted from one type of stem cell."

Related Stories

Researchers generate kidney tubular cells from stem cells

December 19, 2013

Researchers have successfully coaxed stem cells to become kidney tubular cells, a significant advance toward one day using regenerative medicine, rather than dialysis and transplantation, to treat kidney failure. The findings ...

Targeting certain kidney cells may help treat kidney failure

January 9, 2014

New research reveals that certain cells contribute to kidney function decline, making them attractive targets for treatments against kidney failure. The findings will appear in an upcoming issue of the Journal of the American ...

Body's fatty folds may help fight kidney failure

March 21, 2014

A fatty fold of tissue within the abdomen that is a rich source of stem cells can help heal diseased kidneys when fused to the organs, according to a study conducted in rats. The findings, which appear in an upcoming issue ...

Printed kidney tissue closer to reality

May 28, 2014

Queensland researchers are one step closer to printing 3D human kidney tissue thanks to a partnership between The University of Queensland and a US biotechnology company.

Recommended for you

Flow means 'go' for proper lymph system development

July 27, 2015

The lymphatic system provides a slow flow of fluid from our organs and tissues into the bloodstream. It returns fluid and proteins that leak from blood vessels, provides passage for immune and inflammatory cells from the ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.