Scientists have found that a particular type of fat tissue may hold the key to the development of rheumatoid arthritis.
A team led by investigators at the University of Colorado School of Medicine reports that synovial adipose tissue was the sole source of messenger RNA for the RA-associated protein profactor D (pro-FD) in its mouse model study.
Working in collaboration with researchers at Fukushima Medical University School of Medicine in Japan, Massachusetts General Hospital for Children, and Brigham and Women’s Hospital, the Colorado group found that cultured differentiated 3T3 adipocytes—which are a surrogate for the fat tissue in question—produced pro-FD but no mature factor D.
"Without factor D, mice cannot get rheumatoid arthritis,” Colorado’st Nirmal Banda, Ph.D., associated professor of medicine, said in a statement.
“We know that fat is normally present around all organs of the body," he added. "But what we didn't know until now was that the fat is secreting this protein which actually triggers arthritis in the joints.”
Based on his team’s discovery of pro-factor D in mice with RA, Banda and his colleagues are now working to develop gene therapies to potentially eliminate the protein in localized areas. He added, though, that this work still must be extended into human studies.
"We are looking at vaccines, drugs or inhibitors to stop the local secretion of pro-factor D in the mouse," Banda said. "Our goal would be to stop the disease before it progresses and leads to joint destruction."
The study, "Roles of Adipocytes and Fibroblasts in Activation of the Alternative Pathway of Complement in Inflammatory Arthritis in Mice," appeared online in The Journal of Immunology on May 6.