"Go small or go home" might be the new catch phrase at the Ohio State University's Comparative Orthopedic Laboratory, where researchers are examining a novel molecular approach to finding the cure for osteoarthritis (OA) in horses. The team recently completed a study using this molecular approach, and the preliminary results they obtained were quite promising.
"Osteoarthritis remains a major problem in horses," explained Alicia L. Bertone, DVM, PhD, Dipl. ACVS, the Trueman Family Endowed Chair and Professor in Equine Orthopedic Surgery at The Ohio State University College of Veterinary Medicine and author on the study. "To date, ways to regenerate cartilage rather than simply reduce inflammation and control pain in affected horses remain to be discovered."
Nutritional supplements and regenerative therapies (such as stem cells and platelet-rich plasma) are currently available and are increasingly popular options for treating OA's clinical signs; however, neither option has "proven" itself via an evidence-based medicine approach.
An alternative method of treating OA is to address the problem at the genetic level, and this was the approach examined by the researchers on the current study.
According to Bertone, "Another possible cure for OA is to interfere with the genetic material to stop proteins that break down cartilage, like interleukin-1 (IL-1), from being produced. This technique, which is called 'RNA inhibition' is currently being explored in human medicine as well."
RNA inhibition uses small interfering ribonucleic acid units (siRNAs) that are specifically designed to bind to a gene product to stop that gene from being expressed, thus reducing or eliminating the problem.
Although this technique currently remains experimental, preliminary data in the laboratory using equine cartilage cell cultures from five clinically normal horses is extremely promising. The procedure has not yet been tested in a live horse.
The study examined the effects of introducing siRNAs to cartilage cells and cartilage explant cultures. Fluorescent siRNAs were used to easily detect where exactly the siRNAs went and what genes they bind to after being added to the cultures. Researchers were able to achieve "robust transfection," meaning the siRNAs were successfully delivered to the cells in culture. Showing that the siRNAs can actually enter the cartilage cells is an important stepping stone in developing this RNA inhibition technique for use in live horses.
The study, "Evaluation of the ability of two transfection reagents to deliver small interfering RNA molecules to equine and guinea pig cartilage in vitro," was published in the June 2011 edition of the American Journal of Veterinary Research. The abstract is available online.
Disclaimer: Seek the advice of a qualified veterinarian before proceeding with any diagnosis, treatment, or therapy.