In a very early sign of medical progress on the osteoarthritis front, scientists report they've used injections of modified genes to reduce the risk that mice will develop the painful, debilitating condition.
There's no way to know if the gene therapy treatment will help humans, and scientists are far from understanding the treatment's side effects and potential cost. But the findings are more than just good news for mice with creaky joints.
"This work identifies an approach that can make a difference," explained study co-author Brendan Lee, M.D., director of the Rolanette and Berdon Lawrence Bone Disease Program of Texas. "There's a great need for treating and preventing osteoarthritis."
The disease, the most common form of arthritis, appears as your joints deteriorate with aging. It often strikes the hands, knees, neck and hips, causing pain, stiffness and difficulty moving.
Seventy percent of Americans aged 55 to 70 struggle with osteoarthritis, for which there is no cure. Doctors try to treat the pain and improve the ability of patients to move, Lee said, and may turn to joint replacement surgeries in advanced cases.
In the new study, researchers examined a protein that diminishes in people with a rare joint disorder. The protein appears to be crucial to the lubrication of joints.
Researchers injected a gene related to the protein into mice and found that the rodent bodies began producing it. The mice appeared to be resistant, but not immune, to damage to the cartilage of joints from injury and aging, Dr. Lee said.
There are plenty of caveats.
The research is in mice, not humans; the next step is to test the approach in horses, whose joints are similar to those of people. And the gene therapy doesn't seem to do anything for damage that's already occurred.
"This kind of therapy would probably not be very useful in patients who have advanced disease," Dr. Lee said, adding that the treatment would likely have to be used with other strategies.
Joanne Jordan, M.D., director of the Thurston Arthritis Research Center at the University of North Carolina at Chapel Hill, said the findings "would be really very exciting if this translates up into humans." The study, she said, appears to be reasonable and especially strong because it looks at osteoarthritis in the mice from different angles.
Currently, Dr. Jordan said, treatments for osteoarthritis, such as painkillers, come with potentially severe side effects. And in many cases, she added, the damage is done by the time people notice there's a problem.
The study is published in the journal Science Translational Medicine.