Gene therapy techniques have been used to help cure horses of lameness, a study involving experts at The University of Nottingham has shown.
By injecting plasmid DNA into the torn ligaments and tendons the researchers were able to see that blood vessels developed within the tissue and the tissue grew back without leaving scar tissue behind. This is essential as it helps the horse to walk, trot and gallop again.
This work, which has been published in the journal Frontiers in Pharmacology, has been carried out as part of a collaborative research project between academics in the University's School of Veterinary Medicine and Science and Kazan Federal University and Moscow State Academy.
This larger study compliments their work published last year and provides more evidence that these techniques could be used to help horses which have gone lame due to tendon or ligament injury.
Dr Catrin Rutland, Associate Professor of Anatomy and Developmental Genetics at The University of Nottingham, said: “This innovative work is truly exciting, not just for veterinary medicine but also in human medicine. Seeing the quick recovery period, the pain relief to the injured animals and watching the blood vessels develop to help the tissue repair was amazing. It gave us real insights into how and why these techniques work.”
Professor Albert Rizvanov, Kazan Federal University who led the study, said “Lameness affects not only the ability to walk but also causes pain. This treatment could potentially be used in not only for horses but other animals and humans with ligament and tendon injuries. The treatments available at the moment often do not work, or result in relapse in 60 per cent of the cases or take many months to work. It is essential that we used horse genes to create this gene therapy treatment. By using specie-specific genes we ensured that proteins which are being synthesized are natural for horse and won’t cause any unwanted immune reactions.”
Veterinary Surgeon Dr Milomir Kovac, said “The horses used in our study had gone lame naturally but with the treatment most of them were back to their previous levels of movement and fitness within a very short time period and were no longer in pain. In addition we did not see the high levels of lameness reoccurring in our patients. The most promising treatments emerging have a 20 per cent relapse rate but also take 5-6 months to work. Our gene therapy worked within just a few weeks. Therefore it has a high rate of healing, a low chance of relapse and works quickly – a significant medical discovery.”
The team had previously reported on two horses who had received cutting-edge treatment but this pioneering larger study helps to show the results in superficial digital flexor tendons and the suspensory ligament branches. Damage to these two areas can cause chronic and debilitating lameness.
The team of scientists and clinicians inserted equine genes for Vascular Endothelial Growth Factor (VEGF164) and Fibroblast Growth Factor 2 (FGF2) into a single plasmid DNA. Once they had injected it inside the injured ligament or tendon, natural horse proteins were produced which helped blood vessels to grow thus promoting healing.
This then ensured that the tissue can grow where necessary to heal the broken tendon or ligament. The team were also able to identify how the genes repair the tissue and the underlying mechanisms.
Professor Albert Rizvanov, who led the world class research, said: “Getting horses fit and active again is an absolute priority for us. With this progressive treatment we can advance medicine in not only tendon and ligament repair but also in other injuries, disorders and in humans.”
The research was funded through a Program of Competitive Growth at Kazan Federal University but the next step for the team is to find funding which will enable them to further develop the treatment in order to further the research and ultimately get it out into clinics and veterinary surgeries.
The research paper, Gene Therapy Using Plasmid DNA Encoding VEGF164 and FGF2 Genes: A Novel Treatment of Naturally Occurring Tendinitis and Desmitis in Horses, is available online at Frontiers in Pharmacology https://www.frontiersin.org/articles/10.3389/fphar.2018.00978/full. Updates are also on dedicated Twitter, Facebook and a dedicated website.