University of Colorado scientists have discovered that fat cells in the knee secrete a protein linked to arthritis, offering hope to millions worldwide. Nirmal Banda, Ph.D., is senior author of the study published this week in the Journal of Immunology. Dr. Banda, associate professor of medicine in the Division of Rheumatology at the University of Colorado School of Medicine, has spent the last 14 years tracking down the causes of rheumatoid arthritis (RA). He has collaborated with University of Colorado professors Michael Holers, M.D., and William Arend, M.D.
“We found that fat in the knee joints secretes a protein called pro-factor D which gives rise to another protein known as factor D that is linked to arthritis, ” said Dr. Banda in the May 8, 2013 news release. “Without factor D, mice cannot get rheumatoid arthritis.”
Now, with the discovery of pro-factor D in mice with rheumatoid arthritis, Dr. Banda is working on gene therapies to eliminate the protein in localized areas. In studies with arthritic mice, Banda previously found that the complement pathway involving factor D made the mice susceptible to inflammatory arthritis.
“We are looking at vaccines, drugs or inhibitors to stop the local secretion of pro-factor D in the mouse, ” he said. “Our goal would be to stop the disease before it progresses and leads to joint destruction.”
In his latest study, Dr. Banda found that removing factor D, rather than the entire complement system, achieves the same result without compromising other parts of the system that can fight infection. And, says Dr. Banda, because the fat does the same thing in all the joints, not just the knees, new medications resulting from this discovery could treat inflammatory arthritis throughout the body.
“The complement system is both friend and foe, ” Banda said. “We believe we can shut down one part of the complement system that triggers disease without shutting down the rest. If so, we will be making a major stride toward treating and perhaps even curing rheumatoid arthritis.”
