Discover What Maybe Fueling One of the World’s Most Common

Newly identified stem cells help explain ligament overgrowth in lumbar spinal stenosis, with mouse experiments pointing to calcium signaling as a possible treatment target. When ligaments in the lower back grow too thick, they can press on spinal nerves, causing pain, numbness, and difficulty walking. This narrowing of the spinal canal, called lumbar spinal stenosis, […].

Share Facebook Twitter LinkedIn Pinterest Telegram Email Reddit Lumbar spinal stenosis is a condition in which the spinal canal in the lower back narrows, placing pressure on nearby nerves. It can cause pain, numbness, weakness, and difficulty walking, and often becomes more common with age. This narrowing of the spinal canal, called lumbar spinal stenosis, affects an estimated 103 million people worldwide.

Researchers are now investigating whether controlling the cells that produce ligament tissue could help treat the condition before surgery becomes necessary. A team at Weill Cornell Medicine and Hospital for Special Surgery has identified stem cells that generate tendons and ligaments. Tendons connect muscles to bones, while ligaments connect bones to one another.

The researchers found that these stem cells become unusually many and active in spinal ligaments affected by stenosis. In mice, they also found a way to block the resulting tissue overgrowth. The study, published in the journal Cell, points to a possible treatment strategy involving calcium signaling, a system cells use to control their activity.

“Identifying these specialized stem cells unlocks a new area of research that allows us to address this disease much more mechanistically, rather than just waiting until a patient’s condition worsens and requires surgery to relieve the nerve compression,” said study co-corresponding author Dr. Sravisht Iyer, an associate professor of orthopedics at Weill Cornell and a spine surgeon at Hospital for Special Surgery (HSS).

“The findings are exciting for their potential to change the way we deliver spinal care.” An image of the Achilles tendon in mice where a new tool marks the tendon stem cell and its daughter cells in green and all other cells in red. All patients provided informed consent before surgery.

Ligaments from patients with stenosis contained more of the stem cells. When transplanted into mice, those cells also produced more tendon cells than stem cells from ligaments without stenosis.

“Though spinal stenosis is a complex condition, this really showed us that these cells are contributing to the pathology,” said co-corresponding author Dr. Matthew Greenblatt, an associate professor of pathology and laboratory medicine at Weill Cornell and a pathologist at NewYork-Presbyterian/Weill Cornell Medical Center.

The researchers then examined what was different about the cells’ activity. Stem cells associated with stenosis had higher levels of calcium signaling than their healthy counterparts.

Genetically increasing that signaling in stem cells from healthy ligaments triggered tissue overgrowth. Reducing it in a mouse model of lumbar spinal stenosis blocked cell overgrowth.

That result raises the possibility of repurposing calcium channel blockers, a class of drugs already used to treat high blood pressure. Clinical studies are still needed to determine whether these drugs could treat spinal stenosis.

“This is probably the first work that’s shown a potential therapeutic target for one of the most common spine conditions in the world,” Iyer said. Ligament stem cells resemble their neighbors Before the team could investigate this connection to disease, it had to establish which cells were responsible for making and maintaining tendons and ligaments.

Greenblatt and his colleagues had previously identified several stem cell populations in bone. In 2018, they found a stem cell in the outer layer of bone that initiates fracture repair.

Later work identified stem cells that form the skull and spine. Tendons and ligaments presented a different challenge.

Medical Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with qualified healthcare professionals for medical decisions and treatment options.