Brain, muscle cells found lurking in kidney organoids grown in lab

Scientists hoping to develop better treatments for kidney disease have turned their attention to growing clusters of kidney cells in the lab. One day, so-called organoids -- grown from human stem cells -- may help repair damaged kidneys in people or be used to test drugs developed to fight kidney disease.

But new research from Washington University School of Medicine in St. Louis has identified rogue cells -- namely brain and muscle cells -- lurking within kidney organoids. Such cells make up only 10 to 20 percent of an organoid's cells, the scientists found, but their presence indicates that the "recipes" used to coax stem cells into becoming kidney cells inadvertently are churning out other cell types.

While at first glance the discovery might be viewed as a setback for using kidney organoids as stand-ins for human kidneys, there's still promise. The researchers found an easy way to prevent most of those wayward cells from forming, and that same approach could be adopted by other scientists who find rogue cells in other organoids, such as those of the brain, lung or heart.

"There's a lot of enthusiasm for growing organoids as models for diseases that affect people," said senior author Benjamin D. Humphreys, MD, PhD, director of the Division of Nephrology. "But scientists haven't fully appreciated that some of the cells that make up those organoids may not mimic what we would find in people.

The good news is that with a simple intervention, we could block most of the rogue cells from growing. This should really accelerate our progress in making organoids better models for human kidney disease and drug discovery, and the same technique could be applied to targeting rogue cells in other organoids."