Matthew Greenblatt, a physician-scientist at Weill Cornell Medicine, says his lab kept finding the same cell in every tendon and ligament it examined, and he calls it “the universal stem cell for tendons and ligaments.” In people with lumbar spinal stenosis, the cell is unusually active. The team’s data point to it as a driver of the ligament overgrowth that narrows the lower spine, and a possible drug target.
The paper appeared in Cell on September 7, 2026, from researchers at Weill Cornell Medicine and the Hospital for Special Surgery in New York. Greenblatt and Sravisht Iyer are the senior researchers named in the announcement, and Lingling Hu, a postdoctoral fellow, is first author.
A stem cell that sits above every tendon cell
Earlier studies had proposed several candidate stem cells for tendon and ligament tissue. In the Weill Cornell announcement, Greenblatt explained that none had shown that a single population could both renew itself and produce the full range of tendon and ligament cell types. The new cell does both, and it appears to be the ultimate origin of all tendon and ligament cells, according to the ScienceDaily summary.
The cells sit in a specialized niche within the tissue and act as a reservoir for growth and repair. The group worked in mice and in human ligament tissue removed during surgery, which allowed a direct comparison between cells from patients with stenosis and cells from people without the condition. Greenblatt said identifying the specialized stem cells opens a new area of research, one that lets investigators approach the disease through its mechanism rather than only through its symptoms, and the comparison between patient and control tissue is what turned that general idea into a specific, testable lead.
Overactivity, calcium and the thickened ligament
The comparison is where the stenosis link comes from. According to News-Medical’s report on the paper, tissue from stenosis patients held more of these stem cells and showed higher activity, and when the stenosis-derived cells were transplanted into mice they produced excessive tendon tissue. The cells also showed elevated calcium signaling relative to healthy counterparts.
To test whether the signal mattered, the team triggered overgrowth in normal cells by manipulating calcium signaling genetically, then did the reverse in a mouse model of stenosis. Reducing calcium signaling blocked the abnormal growth. The result is evidence that the pathway is involved in the thickening, though the work establishes it in mice and in cultured or transplanted human cells rather than in treated patients.
The aging spine and the drug question
For patients, the practical result of a thickened ligament is a smaller canal for the nerves. The institute’s description includes a telling symptom: sitting or flexing the lower back may ease the pain, because bending forward widens the spaces between vertebrae. That relief is why many people with stenosis can walk only short distances before needing to sit, and why a cause upstream of the narrowing, in the cells that build the ligament, would be a different kind of target from pain control.
Lumbar spinal stenosis affects an estimated 103 million people worldwide, according to the Weill Cornell team. The National Institute of Arthritis and Musculoskeletal and Skin Diseases describes it as a narrowing of the spaces in the spine that presses on the spinal cord and nerve roots, notes that the ligaments holding the vertebrae in place may thicken and calcify, and says the chances of developing it rise with age.
Treatment today is aimed at symptoms. The Hospital for Special Surgery’s patient page lists physical therapy, anti-inflammatory drugs and steroid injections, with laminectomy, a decompression surgery that removes the bony roof over the nerves, when those fail. Iyer called the new work “probably the first work that’s shown a potential therapeutic target for one of the most common spine conditions in the world.”
Surgery is the endpoint of that pathway, and the Hospital for Special Surgery’s page reports a success rate of roughly 85 percent for laminectomy there. A drug that slowed the growth of the ligament, if one emerged, would aim to move the decision point earlier, before nerve compression forces an operation. That outcome is a hope attached to a mouse experiment, and the Cell paper does not claim it.
The target suggests an unexpected shortcut. Calcium channel blockers are already prescribed for high blood pressure, and the researchers say the findings support studying them in spinal stenosis. No patient has been given one for this purpose in the study, and Weill Cornell says clinical studies are needed before any recommendation can be made. Greenblatt also pointed to a broader use for the stem cell: poor healing in rotator cuff tears, Achilles injuries and chronic tendon degeneration, where a cell that rebuilds tendon could matter as much as one that overbuilds it.
This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.
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