Apoptosis in epithelial cells and its correlation with leukocyte accumulation in lamellar tissue from horses subjected to experimental sepsis-associated laminitis.

This research investigates the occurrence of cell death and inflammation in horse hoof tissue during the early stages of a hoof disease called laminitis that is associated with sepsis. It concludes refuting the assumption that cell death, or apoptosis, plays a significant role in the initial stages of this condition.

Research Context and Methodology

• This study focuses on the disease of laminitis, a painful condition affecting horse hoofs that can often be caused by sepsis (a potentially life-threatening condition caused by the body’s response to an infection).
• The primary focus was to understand the role of apoptosis (programmed cell death) and inflammation (a biological response to harmful stimuli) in the early stages of sepsis-related laminitis, as it was unclear whether apoptosis occurs before inflammation or is caused by it.
• The researchers carried out experiments on lamellar tissues (thin layers of tissue in the horse’s hoof) taken at different stages of laminitis induction, observing for the presence of apoptotic cells and leukocytes (white blood cells indicative of an inflammatory response).
• These tissue samples were obtained from previous experiments where acute laminitis was triggered using Black Walnut Extract (BWE) or starch (CHO). The samples were then grouped based on the time after laminitis induction and the onset of lameness (a visible indication of laminitis).

Findings and Conclusions

• Apoptotic cells were counted using a technique specifically validated for horses, known as TUNEL.
• The results revealed no significant increase in the number of apoptotic cells in the studied samples compared to the controls during the developmental phase or at the onset of lameness, indicating that apoptosis is not a key factor in the early stages of sepsis-related laminitis.
• However, a negative correlation was discovered between the count of apoptotic cells and the infiltration of leukocytes in the BWE model, suggesting that as cell death decreases, the immune response (as indicated by leukocyte infiltration) increases.
• In essence, the study concludes that apoptosis does not play a significant role in the initial stages of sepsis-related laminitis in horses.