21 August 2012
A novel stem-cell treatment may hold the key to treating osteoarthritis triggered by joint injury, suggest results from an animal study.
Joint injury is a common causative factor for osteoarthritis, particularly in cases of intra-articular fracture, and is implicated in around 12% of all cases of the condition.
Farshid Guilak (Duke University, Durham, North Carolina, USA) and team tested whether an injection of purified mesenchymal stem cells (MSCs) extracted from “superhealer” and normal mice would normalize inflammation and improve regeneration after knee fracture in a mouse model.
The researchers believed that the MSCs taken from the superhealer mice would produce better results than those extracted from normal mice, due to the exceptional regenerative abilities shown by this strain of mice.
However, “instead, we found that they were no better than stem cells from typical mice. We thought that maybe it would take stem cells from superhealers to gain an effect as strong as preventing arthritis after a fracture, but we were surprised – and excited – to learn that regular stem cells work just as well,” said study co-author Brian Diekman, also from Duke University, in a press statement.
As reported in Cell Transplantation, the investigators compared the outcomes of three groups of mice with knee fracture treated with the superhealer or normal MSCs or a saline control.
They found that while the control mice developed symptoms of post-traumatic arthritis (PTA) after 8 weeks, neither of the stem cell-treated groups displayed any such symptoms.
“The stem cells changed the levels of certain immune factors, called cytokines, and altered the bone healing response,” commented Diekman.
He added that production of an adequate quantity and quality of MSCs could be a potential problem for this sort of treatment. But “we found that by placing the stem cells into low-oxygen conditions, they would grow more rapidly in culture so that we could deliver enough of them to make a difference therapeutically,” he explained.
The authors conclude that their study “provides evidence that intra-articular stem cell therapy can prevent the development of PTA after fracture and has implications for possible clinical interventions after joint injury before evidence of significant osteoarthritis.”