Neutrophil extracellular traps and active myeloperoxidase concentrate in lamellar tissue of equids with naturally occurring laminitis.

The research investigates the role of myeloperoxidase (MPO) and neutrophil extracellular traps (NET) in the development of laminitis in equines naturally, suggesting that these elements can be targeted for future treatment development.

Introduction

This research focuses on laminitis, a serious degenerative condition that affects the hooves of horses and donkeys, leading to the failure of the bond between the hoof wall and bone. The study specifically delves into the role of neutrophil activation, a crucial element in the development of laminitis. Neutrophils are a type of white blood cell and when they are activated, they release substances like myeloperoxidase (MPO) and neutrophil extracellular traps (NET).

Objective of the Study

• The purpose of this study was to investigate the presence and activity of MPO and NET in the lamellar tissue of donkeys and horses suffering from naturally occurring laminitis.

Methodology

• The researchers collected lamellar tissue samples from five horses and five donkeys with laminitis, and from eight healthy horses.
• MPO and NET presence and activity in the tissue extracts were confirmed using ELISA and SIEFED assays.
• Additionally, immunohistochemical staining was used for visual confirmation of MPO and NET presence within the tissues.

Key Findings

• The analysis revealed that laminitis-affected equids had significantly high levels of total MPO concentration and NET-bound MPO activity compared to the control horses.
• This suggests that MPO activity originates, at least in part, from NET-bound MPO.
• Immunohistochemical staining showed noticeable MPO and NET presence in the lamellar tissues of laminitis-affected equids, especially in the epidermis and in inflammatory infiltrates that contain neutrophils. In contrast, control horses showed minimal staining for MPO and NET.

Conclusion

• This study suggests for the first time that NET-bound MPO plays a role in laminitis, making it a potential target for further research and new treatment development.