Purmessur Leads Low Back Pain Study on New Treatments for People and Pets

Posted: October 22, 2020
Devina Purmessur

Biomedical Engineering Assistant Professor Devina Purmessur continues to attract attention and funding for her lab’s work on chronic back pain.  Following an R61 award from the National Institutes of Health NIH) last year, she recently earned an NIH R21 award to investigate potential treatments for intervertebral disc degeneration.

Purmessur’s team will perform the research on dogs with intervertebral disc disease and on chondrodystrophic canine in vitro cell cultures. Chondrodystrophy refers to the "long and low" body shape characteristic of many dog breeds including dachshunds and corgis. This gene mutation also increases the risk of disc disease in these breeds.

In addition to its effects on quality of life, chronic low back pain in people exerts a significant socioeconomic burden. As many of its sufferers try to manage the pain with prescription drugs, it also has contributed to the growing opioid crisis, which is now a national research priority.

According to Purmessur, director of the Spinal Therapeutics Lab and faculty member of the Spine Research Institute, most current surgical and non-surgical treatments focus on alleviating the pain. “The problem with focusing on just the pain, is that it doesn’t fix the disease,” she explained. “You’re just treating the symptoms.”

Intervertebral disc (IVD) degeneration is highly associated with low back pain, and blood vessel and nerve growth into the disc have been identified in patients with chronic pain. However, the specific pathways propagating the ingrowth and causing pain have yet to be identified. Purmessur believes mast cells play a role. Present in connective tissues throughout the body, mast cells regulate inflammation and pain in musculoskeletal diseases such as rheumatoid arthritis and osteoarthritis. They are considered to be part of the innate immune system.

Her team’s published and supportive work have demonstrated significantly increased levels of mast cell marker tryptase in the IVDs of human and canine patients with painful disc degeneration, suggesting that mast cells function to enhance catabolism, inflammation and pain pathways in discogenic back pain.

The $377,520, two-year grant will fund a low back pain study to determine the role of mast cells and protease-activated receptor 2—a protein that modulates inflammatory responses among other things—and how they can be used for therapeutic effect. According to Purmessur, immune-modulation has never been applied to IVD degeneration as a non-addictive strategy to treat low back pain.

microscopic images of canine intervertebral cells
Histological tissue staining of cells (left) in the dog intervertebral disc joint; (middle) mast cells in vitro; (right) immunohistochemical staining for target pathway protease-activated receptor 2 in disc tissue

Purmessur said that the chondrodystrophic dog is currently under-utilized as an intermediate animal model of low back pain despite its similarities to disc degeneration in humans. The research also carries veterinary care value.

“A large animal model is a necessary step toward beginning human patient clinical trials,” she added, “but there also is significant potential benefit in reducing pain and suffering of companion animals currently seen in veterinary clinics.”

Collaborators include College of Veterinary Medicine Associate Professor Sarah Moore and Assistant Professors Joelle Fenger and Kara Corps, as well College of Medicine Associate Professor Candice Askwith, Biostatistician Brett Klamer and Dr. Safdar Khan, the Benjamin R. and Helen Slack Wiltberger Endowed Chair in Orthopaedic Spine Surgery.

This article was first posted September 25, 2020 by The Ohio State University's College of Engineering.