Integrins in biliary injury and fibrosis

Abstract

Purpose of review Current treatment options for cholangiopathies are severely limited and there is thus a critical need to identify and develop therapies. This review discusses the role of integrins in biliary injury and fibrosis and their potential as therapeutic targets. Recent findings There are a diverse set of roles that integrins play in biliary injury and fibrosis. Some integrins activate TGF-β signaling or are involved in sensing of the extracellular matrix, making them attractive targets for biliary fibrosis. In recent work, autoantibodies to αvβ6 were identified in patients with PSC, supporting the relevance of this integrin in the disease. In addition, a role for α2β1 in cyst formation was identified in a mouse model of polycystic liver disease. Leukocyte integrins (e.g. αEβ7 and α4β7) contribute to lymphocyte trafficking, making them potential targets for biliary inflammation; however, this has not yet translated to the clinic. Summary While all members of the same family of proteins, integrins have diverse roles in the pathogenesis of biliary disease. Targeting one or multiple of these integrins may slow or halt the progression of biliary injury and fibrosis by simultaneously impacting different pathologic cells and processes.