Stem cell could be key to chronic kidney disease treatment

Calcification of blood vessels is common among patients with chronic kidney disease. And researchers in St. Louis have found that a type of stem cell causes the clogging and could possibly be fought.

Scientists at the Washington University School of Medicine published a study in the journal Cell Stem Cell that showcases Gli1 positive stem cells as the ones responsible for clogging blood vessels with mineral deposits. They can become any kind of cell from muscle to bone, and in healthy conditions, according to the university, that characteristic can help them heal damaged vessels.

But in chronic kidney disease, the cells become confused and begin to build osteoblasts, which would build bone instead of smooth muscle cells. This would account for the depositing of calcium.

“We expect to find osteoblasts in bone, not blood vessels,” lead researcher Benjamin Humphreys said in a release. “In the mice with chronic kidney disease, Gli1 cells end up resembling osteoblasts, secreting bone in the vessel wall. During kidney failure, blood pressure is high and toxins build up in the blood, promoting inflammation. These cells may be trying to perform their healing role in responding to injury signals, but the toxic, inflammatory environment somehow misguides them into the wrong cell type.”

In mice that had their Gli1 cells removed, the calcification process stopped. So by identifying which cells control the process, the scientists can test ways to block it, Humphreys said. But they don’t want to remove the cells completely from a patient, because they play an important role in healing.

“More recently, we’ve learned that calcification is an active process directed by cells,” Humphreys said in the release. “But there has been a lot of controversy over which cells are responsible and where they come from.”