Matrix metalloproteinases in inflammatory pathologies of the horse.

This research article explores the role of matrix metalloproteinases (MMPs) in the inflammatory diseases of horses, focusing on how these enzymes contribute to certain pathologies, including laminitis and osteoarthritis, and the potential effects of their therapeutic intervention.

Role of Matrix Metalloproteinases

• The study focuses on MMPs, enzymes that play a critical role in the maintenance of the extracellular matrix (ECM) of connective tissues, structures key to body growth and regeneration.
• MMPs facilitate the degradation of the ECM components and their subsequent re-synthesis, maintaining a balance that is essential for normal tissue function.
• The proteolytic action of MMPs is primarily controlled by tissue inhibitors of metalloproteinases (TIMPs). Both MMPs and TIMPs exist in a dynamic equilibrium, with a slight predominance of either side depending on the need for ECM breakdown or synthesis.

MMP Dysregulation and Disease

• Long-term disruption to this balance between MMPs and TIMPs can have pathological consequences. The paper outlines how MMPs are involved in a number of diseases in mammals, including horses.
• Excess MMP activity can lead to the destruction of the ECM, manifesting as diseases like laminitis (affecting the lamellar basement membrane) and osteoarthritis (involving the articular cartilage).
• Conversely, a lack of MMP activity can slow healing by preventing fibrinolysis in fibrotic conditions and the removal of scar tissue in wounds.

Additional Functions of MMPs and Therapeutic Intervention

• MMPs are also capable of degrading non-ECM proteins and can regulate cell behaviour through the release of growth factors from the substrates they break down, which broadens their impact.
• The article reviews the engagement of MMPs in equine health and diseases and speculates on the potential repercussions of therapeutic intervention targeting these enzymes.