Hepatocyte survival depends on β1-integrin-mediated attachment of hepatocytes to hepatic extracellular matrix


Gabriëlle Pinkse, BSc, Department of Pathology, Leiden University Medical Center, P.O. Box 9600, Building 1, L1-Q 2300 RC Leiden,
The Netherlands.
Tel: +31-71-5266625
Fax: +31-71-5248158
e-mail: G.Pinkse@lumc.nl


Abstract: Background: A major drawback of allogeneic hepatocyte transplantation is the lack of sustained survival of the transplanted cells in the recipient liver parenchyma. The purpose of this study was to determine the effect of the presence or absence of hepatic extracellular matrix (ECM) molecules on hepatocyte survival and function following hepatocyte isolation for transplantation purposes, and the role of β1-integrin molecules therein.

Methods: Hepatocytes, either untreated or treated with anti-β1 integrin antibodies or RGD peptides, were seeded on wells precoated with collagen type I, type IV, laminin, fibronectin or polyhydroxyethylmehacrylate. The extent of attachment and apoptosis was evaluated.

Results: When hepatocytes were added into wells precoated with either fibronectin, or collagen type IV, rapid spreading and prolonged survival occurred, in contrast to hepatocytes that were seeded in wells precoated with collagen type I or polyhydroxyethylmehacrylate. Pretreatment of the cells with anti-β1-integrin antibodies resulted in reduction of cell attachment to laminin, fibronectin, collagen I, and collagen IV. Synthetic RGD (arginine–glycine–aspartate)-peptides and anti-β1 antibodies inhibited apoptosis of cultured hepatocytes.

Conclusions: Our findings indicate that embedding of hepatocytes within their normal liver ECM surroundings maintains their survival. When detached from their natural surrounding hepatocytes enter into apoptosis, unless treated with anti-β1-integrin antibodies or RGD peptides. This knowledge will allow improvement of hepatocyte transplantation efficiency.