Activation of focal adhesion kinase and JNK contributes to the extracellular matrix and cAMP-GEF mediated survival from bile acid induced apoptosis in rat hepatocytes

JOURNAL OF HEPATOLOGY

卷:49

Article

Usechak, Paul¹  Gates, Anna¹  Webster, Cynthia R. L.¹ 

[1] Tufts Cummings Sch Vet Med, Dept Clin Sci, North Grafton, MA 01539 USA

关键词: cAMP-GEF;    exchange protein regulated by cAMP (EPAC);    phosphoinositide 3-kinase (PI3K);    bile acids;    focal adhesion kinase;    JNK;    extracellular matrix;    collagen;    polylysine;    laminin;   

DOI  :  10.1016/j.jhep.2008.04.015

来源: Elsevier

【 摘 要 】

Background/Aims: Adherence to an extracellular matrix (ECM) rescues hepatocytes from apoptosis, but how hepatocytes adhered to different ECM and respond to apoptotic and cytoprotective stimuli is unknown. Methods: Rat hepatocytes were plated on type 1 collagen (CI), laminin (LM) or polylysine (PL) and the amount of apoptosis induced by glycochenodeoxycholate (GCDC), deoxycholate (DCA), Fas ligand or serum withdrawal was determined by Hoechst staining. The response to cytoprotection by cAMP-guanine exchange factor (cAMP-GEF) activation was determined. Kinase activation was determined by immunoblotting with phosphospecific antibodies. Results: Hepatocytes on LM and PL had more apoptosis in response to all apoptotic stimuli. GCDC increased c-jun-N-terminal kinase (JNK) phosphorylation 2-fold in hepatocytes on CI, but 15- and 30-fold in hepatocytes on PL or LM. SP-600125, a JNK inhibitor, prevented LM and PL potentiation of bile acid apoptosis. GCDC induced dephosphorylation of focal adhesion kinase (FAK) was prevented by cAMP-GEF activation. Cytochalasin B which decreased FAK phosphorylation prevented cAMP-GEF cytoprotection. Conclusions: JNK activation augments apoptosis in hepatocytes plated on PL and LM. Decreased FAK phosphorylation as seen in cells treated with bile acids or attached to PL and LM promotes hepatocyte apoptosis. (C) 2008 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

【 授权许可】

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