A simple protein may be a key instigator in the breakdown of bone that leads to osteoporosis and several inflammatory joint diseases, such as rheumatoid arthritis.

A team of scientists at the University of Central Florida, led by Pappachan Kolattukudy, conducted a series of experiments with human bone marrow-derived cells. They found the protein MCPIP (Monocyte Chemotactic Protein-1 Induced Protein) plays a major role in the formation of osteoclasts, the cell type that’s directly responsible for bone breakdown.

Kolattukudy’s findings are published in today’s issue of the

About one in five American women over the age of 50 have osteoporosis, a disease that thins bone tissue and causes loss of bone density, leading to a higher risk of fractures.

Rheumatoid arthritis affects about 1.3 million Americans every year. It is caused by joint inflammation, and researchers now suspect the disease also begins damaging bone during its first year.

The protein – MCPIP – is linked to both.

Kolattukudy and his team first identified MCPIP in 2006 when they discovered that the protein contributes to heart disease. Three years later, they found that MCPIP also plays a role in controlling the body’s fat-building process and new blood vessel formation.

This latest research shows that MCIP also is linked to inflammation, which disrupts a body’s proper balance and leads to bone and other health problems.

“Bone loss (by osteoclasts) and bone building (by osteoblasts) happen all the time,” Kolattukudy said.  “Inflammation turns the balance toward bone loss.”

Scientists already knew that another protein – Monocyte Chemotactic Protein-1 (MCP-1) – played a role in the development of osteoclasts, the cells that break down bone.

But Kolattukudy’s lab has now found that MCPIP is a key player in controlling whether cells build or lose bone. This discovery opens up potential new therapeutic targets for fighting the debilitating diseases caused by bone loss.

Kolattukudy, director of the Burnett School of Biomedical Sciences at UCF led a team that also includes Kangkai Wang, Jianli Niu and Hyunbae Kim all of UCF.