Enhanced Oxidative Stress and Ultrastructural Changes in Damaged Laminar Tissue of Acute Laminitis Induced by Oligofructose Overload in Dairy Cows

This study explored the Ultrastructural and oxidative stress-related genes and proteins changes in the laminar tissue of dairy cows with oligofructose (OF)-induced laminitis. Twelve clinically healthy, non-pregnant Chinese Holstein cows were randomly allocated into two groups: OF-overload group (n = 6) and Control group (n = 6). 17g/kg BW of oligofructose (OF) dissolved in 20 mL/kg BW of deionized water was provided to the OF-treated group, while the control group received 20 mL/kg BW of deionized water via a stomach tube. Laminar tissue samples were collected after euthanizing cows at 72 h. We observed that the gene and protein expression of Nrf2, Ho1, and Nqo1 significantly decreased, while keap1 significantly increased in the OF group as compared to the control group. Moreover, the distribution of Keap1 expression significantly increased, while that of the Nrf2 significantly decreased in the OF group relative to the control group. However, in the OF group, the lamina densa appears thick and damaged, with interrelated collagen fibers, and lightly stained; number of hemidesmosomes on the cell membrane decreased; the distance between the basal cells and the epidermal lamellae increased; epidermal basal cells have deformed nuclei with reduced chromatin than in control cows. In conclusion, unbalanced gene and protein status may be the stem cause for the epidermal detachment which confirmed the increased oxidative stress in the OF group.