Managing Equine Metabolic Syndrome: Stem Cells Explored

 As our understanding of stem cells improves, scientists employ them in increasingly creative ways. Use of stem cells is now being explored in horses affected with equine metabolic syndrome (EMS).

Horses diagnosed with EMS are currently managed with diet, exercise, and sometimes sodium glucose co-transport-2 inhibitors, but not all horses respond adequately to these measures. New research into laboratory-derived liver-type stem cells may help pave the way to restore liver function in horses affected by EMS.

“Typically, when we discuss EMS, the focus is on improving insulin sensitivity and preventing hyperinsulinemia-associated laminitis. Important changes also occur in the liver, and these should be addressed,” explained Kathleen Crandell, Ph.D., a nutritionist for Kentucky Equine Research.

Detrimental liver changes are associated with insulin resistance. These include liver fibrosis (scarring) and hepatitis (inflammation) secondary to injured hepatocytes releasing proinflammatory mediators.

To help combat this liver damage, University of California, Davis, researchers in collaboration with a group of Polish scientists conducted a study to determine if cell-based therapies could help regenerate insulin-resistant liver tissue.^*

“Although previous studies found that using adipose-derived stem cells (ASCs) directly did not possess clinical value in EMS horses, the research team instead focused on ‘liver progenitor cells’ derived from ACSs as a novel treatment approach for EMS,” explained Crandell.

In that study, adipose tissue was collected from healthy horses. Using a series of laboratory culture techniques, those ASCs underwent a “guided transformation” into liver progenitor stem cells.

Some positive preliminary results were obtained, primarily that the liver progenitor cells exhibited “stemness.” With further research and development, those cells could ultimately prove to have a therapeutic capacity for liver regeneration and insulin sensitization (i.e., making the liver more responsive to the effects of insulin).

Even with stem cells and medications, an EMS horse’s diet must be managed as it provides the pillars upon which all other treatments are built upon.

“Controlling dietary intake of feedstuffs that can lead to rises in blood glucose is key to managing EMS. This includes feeding a hay lower in nonstructural carbohydrates (<12%) balanced with a vitamin and mineral supplement or a ration balancer feed,” Crandell advised.

Not all horses diagnosed with EMS are overweight, however. “In the rare case that an EMS horse needs more energy, then nutrient-dense fiber feeds like hay pellets or rinsed beet pulp can provide the extra calories in a form that avoids the rises in blood glucose,” she said.

Kentucky Equine Research also offers EO-3, a source of the long-chain polyunsaturated fatty acids known as DHA and EPA, which reduce systemic inflammation.

“Inflammation was associated with the liver damage described in this study, and the DHA and EPA found in marine-derived oil improve insulin resistance in humans,” Crandell added.

^*Marycz, K., N. Bourebaba, A. Serwotka-Suszczak, M. Mularczyk, L. Galuppo, and L. Bourebaba. 2023. In vitro generated equine hepatic-like progenitor cells as a novel potent cell pool for equine metabolic syndrome (EMS) treatment. Stem Cell Reviews and Reports. doi: 10.1007/s12015-023-10507-3.