OB‐cadherin cloning and expression in a model of wound repair in horses

Reason for performing study: Horses suffer from a debilitating impediment in repairing wounds located on the lower limb that leads to the development of a fibroproliferative disorder (exuberant granulation tissue). This condition is a source of wastage since it often forces retirement from competition. Treatments that resolve or prevent this condition are still lacking, maybe due to deficient knowledge of the underlying molecular mechanisms. Fibroblast‐to‐myofibroblast conversion is an essential step allowing contraction during wound repair and is accompanied by an increase in OB‐cadherin expression. Objectives: To clone equine cadherin‐11 (CDH11) cDNA and to study its spatiotemporal expression profile during the repair of body and limb wounds, thereby contributing to a better understanding of the repair process. Methods: Cloning was by a PCR technique. Expression was studied in intact skin and in 1, 2, 3, 4 and 6‐week‐old wounds of the body and limb. Temporal CDH11 gene expression was determined by RT‐PCR while OB‐cadherin protein expression was mapped immunohistochemically. Results: Equine CDH11 is a highly conserved gene and protein. mRNA was not expressed in equine skin whereas the wound repair process was characterised by a significantly higher expression in the thorax than in limb samples. mRNA expression pattern was paralleled by protein data as confirmed by immunohistochemistry. Conclusions: The data suggest that deficient OB‐cadherin expression in the first phases of wound repair contributes to the excessive proliferative response seen in horse limb wounds. Potential relevance: Future studies should verify the quantitative, temporal expression of this protein in order to provide the basis for targeted therapies that might prevent the development of EGT in horse wound repair.