Researchers From Rush Identify a Cause of Osteoarthritis Pain
Researchers from Rush have identified a molecular mechanism central to the development of osteoarthritis pain. The discovery, published in the Dec. 11, 2012, print edition of the Proceedings of the National Academy of Sciences, could have major implications for future treatment.
"Clinically, scientists have focused on trying to understand how cartilage and joints degenerate in osteoarthritis," says Anne-Marie Malfait, MD, PhD, lead author (with Rachel Miller) of the study and associate professor of biochemistry and internal medicine at Rush. "But no one knows why it hurts."
In a longitudinal study of mice that underwent surgical procedures mimicking the disease's progression, Malfait and her colleagues found that a chemokine known as monocyte chemoattractant protein (MCP)-1 (CCL2) and its receptor, chemokine receptor 2 (CCR2), play a significant role in the development of knee osteoarthritis pain.
Their research indicates that increased expression of MCP-1 and CCR2 can escalate pain signaling by attracting macrophages to the dorsal root ganglion (DRG) and by directly exciting DRG neurons.
"This is an important contribution to the field of osteoarthritis research," says Joshua Jacobs, MD, chairperson of orthopedic surgery at Rush. "Rather than looking at the cartilage breakdown pathway in osteoarthritis, Dr. Malfait and her colleagues are looking at the pain pathway, and this can take osteoarthritis research in a novel direction that could lead to new pain remedies in the future."