Gene Protects Mice from Arthritis A substance commonly added to toothpaste to prevent tartar accumulation on our teeth may be the same material our bodies uses to prevent calcium and minerals from accumulating in our joints and forming the deposits associated with arthritis. Stanford University scientists have found a mouse gene that transports this substance, pyrophosphate, into and out of cells. If the gene is defective, the animals have severe arthritis. The researchers also identified the human version of the gene and confirmed that it lies in a region of DNA previously implicated in human joint disease, suggesting that disruptions in this gene may underlie arthritis in many different animals. Kingsley is senior author of a paper describing the findings in the July 14 issue of Science.
Arthritis is one of the most common human health problems.
Its underlying causes are not well understood but genetic factors are believed to account for half to two thirds of human cases, including the most common types such as osteoarthritis, rheumatoid arthritis and ankylosing spondylitis, said Kingsley. The incidence of osteoarthritis, the most common joint disease of humans, increases with age and is most frequent in people over the age of 60. Mice carrying the defective ank gene have long been studied as a model of arthritis. These mice have decreased mobility of their ankle and toe joints, which progresses as to most joints throughout the limbs and spinal column. Like arthritis in humans, the condition becomes more severe with increasing age.