Oral Oligofructose Challenge Induces Apoptosis in Damaged Laminar Tissue of Acute Laminitis in Dairy Cows

The objective of this research was to examine apoptosis status in the laminar tissue of dairy cows with OF-induced laminitis. A total of 12 clinically healthy non-pregnant Holstein cows were randomly allocated into 2 groups of 6 cows each: the control group and the oligofructose treated group (OF group), respectively. At 0 h, 17 g/kg BW of oligofructose dissolved in 20 mL/kg BW of warm deionized water were administered to the dairy cows of OF group via a stomach tube, and dairy cows in control group were received with the said volume of deionized water by the same method. At -72 h before and 0 h, 6 h, 12 h, 18 h, 24 h, 36 h, 48 h, 60 h, and 72 h after OF overload, clinical examination in both groups were performed. After 72 h, laminar tissues of dairy cows in both groups were taken to determine genes and proteins. We observed that the gene expression of Bax (P<0.01), and P53 (P<0.05) significantly up-regulated, whereas that of Bcl2 significantly down-regulated (P<0.01) in the afflicted cows compared to the control cows. The protein expression of Bax (P<0.01), Bif1 (P<0.01), caspase3 (P<0.01), caspase8 (P<0.05), and caspase9/9p (P<0.05) significantly up-regulated, while that of Bcl2 significantly downregulated (P<0.01) in the afflicted cows compared to the control cows. Moreover, the distribution of Bax (P<0.01) and P53 (P<0.01) proteins in laminar tissue significantly up-regulated (P<0.01) in the sick cows compared with the control cows. These results suggested that unregulated genes and proteins status of apoptosis-associated indicators may be a typical cause for epidermal attachment failure which serves a key role in the pathogenesis of dairy cow laminitis. Nevertheless, further large-scale gene and protein-level studies are required to fully explain the pathogenesis of laminitis in dairy cows.