“A Hypertension Drug as a Treatment for Spinal Disease”: Stem Cells That Generate Tendons and Ligaments Identified

U.S. researchers have identified “master stem cells” that produce tendons and ligaments in the human body. A study found that when these cells become overactive, they cause a condition that narrows the spinal canal in the lower back, and that a hypertension drug could offer a new treatment.

A joint research team from Weill Cornell Medicine and Hospital for Special Surgery (HSS) published the findings in the international journal Cell on the 7th (local time).

The researchers identified undifferentiated stem cells that produce tendons and ligaments, which connect muscles and bones. The cells were found to cause spinal stenosis when overactivated in the lower spine.

Spinal stenosis is a condition in which thickened ligaments narrow the spinal canal and compress nerves. About 103 million people worldwide have the condition, which causes pain, numbness and difficulty walking.

The researchers also confirmed that these stem cells are not limited to the spine. “We found these cells in every site we examined, including knee ligaments and the Achilles tendon,” said Matthew Greenblatt, an associate professor in the Department of Pathology and Laboratory Medicine at Weill Cornell Medicine. “We consider them universal stem cells for tendons and ligaments throughout the body.”

The researchers compared stem cells collected from patients with spinal stenosis with cells from healthy people. The ligaments of patients with stenosis had more stem cells, and when the cells were transplanted into mice, they produced more tendon cells than healthy stem cells did.

At the molecular level, stem cells associated with stenosis showed higher calcium signaling than normal cells. When the researchers used genetic engineering to increase calcium signaling in healthy ligament stem cells, the tissue grew excessively.

Conversely, suppressing calcium signaling in a mouse model of spinal stenosis stopped the cells from overgrowing. The researchers said they believe calcium channel blockers, currently used to treat hypertension, could be repurposed to treat spinal stenosis, and that clinical studies are needed.

“This may be the first study to identify a potential therapeutic target for one of the most common spinal disorders in the world,” said co-corresponding author Sravisht Iyer, an associate professor of orthopedic surgery at Weill Cornell Medicine.

The researchers hope these stem cells will also offer clues for treating connective tissue disorders such as Marfan syndrome, as well as tendon and ligament conditions such as rotator cuff tears and Achilles tendon injuries.