Osteoarthritis is a major cause of chronic pain and limited mobility. Researchers have now presented a possible treatment approach: using cartilage cells from the nasal septum, they have succeeded in repairing cartilage damage in the knee caused by osteoarthritis in mice, sheep and two patients. The nasal cartilage cells not only withstood the stresses caused by the chronic inflammation in the knee, but even counteracted the symptoms of inflammation. The researchers now want to test the treatment on additional patients in clinical studies.
Millions of people worldwide suffer from osteoarthritis, a degenerative joint disease in which the cartilage is progressively damaged and broken down. So far, only treatment options for the symptoms are available that counteract the inflammation and the associated pain, but can neither stop the course of the disease nor regenerate the lost cartilage. As a last resort, prostheses are an option. However, since their shelf life is limited, this option is particularly unfavorable for young people.
From the nose to the knee
A team led by Lina Acevedo Rua from the University Hospital Basel has now found a possible treatment for osteoarthritis of the knee: a natural replacement from the patient’s nasal cartilage. For many years, the research team has been working on the question of how nasal cartilage cells can help repair damaged cartilage elsewhere in the body. “Unlike cartilage from joints, cartilage cells can be removed very easily from the nasal septum and are also easier to multiply,” the researchers write. “The nasal cartilage is also healthy in osteoarthritis patients.”
However, osteoarthritis posed challenges for the researchers. While they have already shown in clinical studies that the replacement from the nose can help for sports injuries, it was not clear for a long time whether the approach is also suitable for patients with osteoarthritis. Because with them, the tissue surrounding the knee is characterized by persistent inflammatory reactions. “We first had to test whether the cartilage replacement was attacked and degenerated by the inflammatory factors,” explains Rua’s colleague Ivan Martin.
Successful in cell culture and animal experiments
To do this, the researchers cultivated cartilage cells from the human nasal septum in the laboratory and exposed them to inflammatory factors that are typical of osteoarthritis. They also implanted cartilage tissue that they had grown from human nasal cartilage cells into the joints of mice and sheep with osteoarthritis. In this way, they were able to test to what extent the cartilage can withstand inflammatory and mechanical loads.
The result: As hoped, the nasal cartilage defied inflammation and developed a stable cartilage matrix in the joint. In addition, it was shown that it even downregulates an important inflammatory signaling pathway in the affected cells and thus alleviates the inflammation. “That could explain why the nasal cartilage gives so good results in the inflammatory environment,” the researchers write. Martin explains about the special properties of the nasal cartilage compared to articular cartilage: “Unlike the cartilage tissue of the joints, these cartilage cells come from precursor cells from a specialized embryonic tissue, the neuroectoderm, and are therefore characterized by a high ability to regenerate and adapt. Tissue grown from nasal cartilage cells could also have these special properties. “
Promising results in human patients
As a next step, Rue and her colleagues treated two patients in their mid-30s who suffered from severe osteoarthritis due to a misalignment of the leg bones. Without the researchers’ experiment, both patients would have needed a knee joint prosthesis. The researchers took cartilage cells from the test subjects’ nose, cultivated them in the laboratory to form stable cartilage tissue and implanted this in the damaged knee joints.
“Both patients stated that they have had less pain and an increased quality of life since the procedure,” the researchers report. In addition, they checked the success with MRI scans of the treated knees, in one patient after three months, in the other after 14 months. “The MRI images showed that a homogeneous repair tissue had formed that filled the defect up to the level of the surrounding cartilage,” said the researchers. In the person who was examined after 14 months, they also found that the bones were again farther apart.
“With our results, we have laid the biological basis for therapy and are cautiously optimistic that we will be able to offer those affected an alternative to knee joint prostheses in the future,” says Martin. The approach is now to be tested in clinical trials with more patients. The researchers also want to work on treating other types of osteoarthritis with the help of nasal cartilage.
Source: Lina Acevedo Rua (University Hospital Basel, Switzerland) et al., Science Translational Medicine, doi: 10.1126 / scitm.aaz4499