Battle of the Bone Growth Proteins: BMP vs Jagged-1

You break a bone. The doctor sets it in plaster and you wait for the bone to heal. Usually it does. But what do you do when it does not heal as expected?

A remedy, bone morphogenic proteins, does not work well with all patients and can have side effects of excessive or altered direction of growth during healing.

Now, researchers at Michigan Medicine, have released a study showing that a protein called Jagged-1 can improve the recovery for bone fractures that do not heal fully.

Kurt Hankenson, D.V.M., Ph.D., lead author and professor of orthopedics at Michigan State University School of Medicine, explains that Jagged-1 is an osteoinducing protein—the kind of protein that stimulates the production of bone. It activates a signaling pathway called Notch, which is involved in bone healing. Significantly, Notch signaling is only activated at the site of injury to the bone.

The way to make it work was to deliver this protein to the site of the action. The study, published in the journal NPJ Regenerative Medicine, describes the researcher’s use of wet collagen sponges to deliver the Jagged-1 protein to femoral bone and skull injuries in laboratory rodents.

One group of animals received BMPs as a treatment. The others received Jagged-1. Both groups improved. Those treated with BMP showed hypertrophy (bone growth) that was misdirected and caused further disruption to the bone structure. There were no outgrowths observed in the Jagged-1 group.

Commenting on the study he led, Hankenson said, “We've hypothesized for many years that by binding the Jagged-1 to a biomaterial and delivering it to a bone injury site, we could enhance healing." The researchers hope that this method will eventually be used to treat humans.