What is a Bone Morphogenetic Protein?

A bone morphogenetic protein (BMP) is a protein in the transforming growth factor (TGF) family that can stimulate the production of bone and cartilage. BMPs play a key role in the formation of the embryonic vertebrae, and also appear to play a key role in signaling the arrangement of other tissue construction in the body as well. Malfunction of that system can cause a disease state.

The discovery of the bone morphogenetic protein is generally attributed to Dr. Marshall Urist in the early part of the 1960s. He discovered that demineralized, pulverized segments of bone prompted the formation of new bone when implanted in rabbit pouches. Dr. Urist is the one who proposed the term bone morphogenetic protein.

There are currently 20 types of bone morphogenetic protein recognized. Originally, there were only seven and six of those, BMP2-BMP7, were considered part of the transforming growth factor beta superfamily. BMP1 is what’s known as a metalloprotease, which is an enzyme whose catalytic process involves metal. Each BMP is located on a specific chromosome.

Bone morphogenetic proteins work by interacting with cell receptors known as bone morphogenetic protein receptors (BMPRs). BMPRs then signal other proteins called SMADs to induce growth. This process contributes to the development of the central nervous system (CNS), the heart, and cartilage. It also contributes to post-natal bone development.

These proteins all play a part in the early formation of the embryo. If the processes and signals they create are disrupted, it can affect the development of the skeletal system and overall body patterning. Research has found that 70% of heritable pulmonary arterial hypertension is caused by mutation in BMPR2. Mutations on the chromosomes, and the related bone morphogenetic protein, can also cause abnormalities and disorders of the skeleton. Cancerous diseases many times involve a malfunctioning of the BMP signaling system as well.

Members of the bone morphogenetic protein have been found to be useful in therapy for the spine. In the United States, BMP-2 and BMP-7 received Food and Drug Administration (FDA) approval for use on humans because they have been found to help with issues where bone structures suffer from non-union and delayed union, two aspects involved in the bone healing process. They can be combined with a bone implant to be released gradually, over a period of weeks, to sustain healing. Although expensive, the BMP treatments can cost less over time, taking into account the number of corrective surgeries that can be required of injuries of the bone. BMP-7 has also been found to help heal damage done to the kidney glomeruli as a result of sclerosis.