A group of researchers in China who have recently observed positive effects of stem cells on patients with rheumatoid arthritis have now conducted an experiment that helps clarify exactly how these stem cells may contribute to improved symptoms in this particular patient population. The group uses umbilical cord stem cells, which are stem cells that have demonstrated immune regulatory functions because the immune system is implicated in rheumatoid arthritis.
Rheumatoid arthritis is characterized by inflammation and subsequent damage to the joints. The synovium is a type of connective tissue located in synovial joints like knees and elbows and is where the majority of the inflammation occurs. A specific protein, called cadherin-11 that is present in some of the cells in the lining of the synovium has been hypothesized to be an important culprit in rheumatoid arthritis because the protein can lead to inflammation and thus destruction of bones and cartilage.
The researchers decided to test whether umbilical cord stem cells may have an impact on cadherin-11, as such an impact could help explain how these cells help patients with rheumatoid arthritis. They therefore looked at fibrolast-like synoviocytes, the cells that express cadherin-11 in the lining of the synovium, in both patients with rheumatoid arthritis and patients with osteopathic arthritis. Because osteopathic arthritis does not involve the same kind of destruction to the synovium that rheumatoid arthritis does, the researchers expected to find less cadherin-11 in the fibroblast-like synoviocytes of the patients with osteopathic arthritis.
Not only did the researchers find, as suspected, that cadherin-11 levels were higher in the fibroblast-like synoviocytes of patients with rheumatoid arthritis, compared to those with osteopathic arthritis, but they also found that umbilical cord stem cells suppressed the cadherin-11 levels in the fibroblast-like synoviocytes from rheumatoid arthritis patients.
These results point to a potential mechanism by which umbilical cord stem cells reduce inflammation and improve symptoms in patients with rheumatoid arthritis. Additionally, they provide important information on how to develop treatments that will specifically target the cause of rheumatoid arthritis.