Designer molecule could offer targeted treatment of osteoporosis and rheumatoid arthritis

A new molecule may be able to treat osteoporosis and other autoimmune diseases in a more targeted way than is currently possible, says research published in Science Signalling. 

Experts from the US have redesigned a molecule that controls immune cell activity, changing the molecule’s target and altering the effects of the signal it sends.

RANKL is a protein that activates cells that dismantle bone; when it becomes too active it leads to a weakening of the skeleton. But the team managed to change RANKL so that it could no longer send its bone-degrading signal, and therefore could no longer cause osteoporosis.

Current treatments for osteoporosis and autoimmune disorders tend to block molecules and their signals in a more general way, increasing risk of infections. But the new approach can selectively block unhelpful signals that cause or contribute to disease, and enhance signals that defend the body against other diseases.

“The molecule we studied controls cells linked to bone weakening, but it belongs to a family of proteins implicated in conditions such as rheumatoid arthritis, psoriasis, Crohn’s disease and asthma,” explains Julia Warren, lead author. “Therefore, this has broad implications for how we might design therapies for a wide variety of ailments.”