Effect Of Celecoxib On Expression Of COX-1/2, Col X And MMP-13 In Thiram Induced TD Broilers

Objectives:Research the relationship between cyclooxygenase pathways and the early occurrence of Tibial dyschondroplasia (TD).Methods: The study is based on previous studies by our group constructing broiler TD early models. Through adding celecoxib, we observed the early clinical symptoms of TD in broilers. By using the growth plate autopsy morphology, histopathological changes, and fluorescence quantitative PCR, immunohistochemistry (IHC) methods, we evaluate TD and detect cyclooxygenase (COX-1/2), metrix metalloproteinasel3 (MMP-13), typeXcollagen (Col X) gene and protein expression.Results:(1) COX-1 and COX-2 protein expressed in normal growth plate, and COX-2 expressed highly; (2) COX expressed differently in early growth plate of TD chicken, COX-1 gene highly expressed at different stages(P<0.01) while protein lowly expressed; COX-2 gene and protein expression also changed at different stages; MMP-13 gene expression increased sharply on day 1 (P<0.01), while has no significant change on days 2 and 4, MMP-13 protein expression was reduced; a great reduce of MMP-13 gene (P<0.01) and protein expression on day 6; ColX gene expression are up-regulated (P<0.01). These results showed that COX-1/2, MMP-13 and ColX expression changes may be related to TD happening; (3) After added celecoxib, Both COX-1 and COX-2 gene (P<0.01) and protein expression recovered to different extent, MMP-13, ColX gene (P<0.01) and MMP-13 protein expression also recovered, the TD severity decreased significantly.Conclusion:Cyclooxygenase pathway may play an important role in the early occurrence of TD.