Hepatic expression of A Disintegrin And Metalloproteinase (ADAM) and ADAMs with thrombospondin motives (ADAM-TS) enzymes in patients with chronic liver diseases

ADAMs (A Disintegrin And Metalloprotease) are multifunctional, membrane-bound and soluble cell surface glycoproteins with numerous functions in cell physiology. We assessed the expression of ADAMs in fibrotic liver disease of different aetiologies and clarified whether the expression of ADAMs is related to histological staging of fibrosis. In addition, the expression of ADAMs was determined in different cell types of liver.Seventy-one biopsy samples from patients with chronic liver diseases were analyzed for mRNA expression of ADAM-8, -9, -12, -28, -TS1, -TS2, matrix metalloprotease (MMP)-2, -9 and tissue inhibitor of metalloproteinases-1 and -2 by quantitative real-time RT-PCR.The ADAM expression in liver injury is independent of aetiology. A strong correlation between ADAM -9, -28, -TS1 versus MMP-2 and SMA was identified. Activated hepatic stellate cells (HSC) showed increased mRNA expression of ADAM-8, -9, -12, -28, -TS2 compared to quiescent HSC. Significant differences between histological stages of fibrosis were found for ADAM-28, MMP-2 and MMP-9.The results suggest that ADAMs are differentially expressed in the liver. We assume that ADAM-9, -TS1 and -TS2 play a crucial role in extracellular matrix remodeling during fibrotic processes in the liver.