Body's Own Molecule Protects Against Osteoarthritis

The discovery of a natural molecule in the body that counteracts the progression of osteoarthritis could lead to new therapies for some common diseases.

The research was performed by an international team of scientists from The Scripps Research Institute in California and the National Research Institute for Child Health and Development in Japan, and was published in the journal Genes & Development.

The molecule is called microRNA 140 (miR-140) is part of the category of genetic molecules known as “microRNAs” or “non-coding RNAs.” These molecules play a role in gene expression, but do not code for proteins.

"This is the first report showing the critical role of a specific non-coding RNA in bone development," said Hiroshi Asahara, M.D., Ph.D., associate professor of molecular and experimental medicine at Scripps Research, in a news release "Moreover, surprisingly, we observed that microRNA 140 acts against arthritis progression. This is among the first evidence that non-coding RNA plays a key role in age-dependent diseases.”

The study focused on examining why the joints of some individuals age normally, while those of others’ do not. The scientists wanted to further examine microRNA, in particular miR-140 and its role in the process. Previous research indicated miR-140, which is only-expressed in cartilage, is reduced in cartilage samples from osteoarthritis patients. The team hypothesized that miR-140 is a regulator in osteoarthritis pathology. The team tried for several years to make targeted “knockout” mouse models that lacked miR-140 and finally succeeded.

The animals that lacked miR-140 were short in statures, which led the scientists to believe that miR-140 affected bone formation during development. Likewise, these mice were prone to developing osteoarthritis, which led to the conclusion that miR-140 retarded the disease. The mice that over-expressed MiR-140 were found to be resistant to developing osteoarthritis.