Lack of Fas antagonism by Met in human fatty liver disease

C Zou, J Ma, X Wang, L Guo, Z Zhu, J Stoops… - Nature medicine, 2007 - nature.com
C Zou, J Ma, X Wang, L Guo, Z Zhu, J Stoops, AE Eaker, CJ Johnson, S Strom
Nature medicine, 2007nature.com
Hepatocytes in fatty livers are hypersensitive to apoptosis and undergo escalated apoptotic
activity via death receptor–mediated pathways, particularly that of Fas-FasL, causing hepatic
injury that can eventually proceed to cirrhosis and end-stage liver disease. Here we report
that the hepatocyte growth factor receptor, Met, plays an important part in preventing Fas-
mediated apoptosis of hepatocytes by sequestering Fas. We also show that Fas antagonism
by Met is abrogated in human fatty liver disease (FLD). Through structure-function studies …
Abstract
Hepatocytes in fatty livers are hypersensitive to apoptosis and undergo escalated apoptotic activity via death receptor–mediated pathways, particularly that of Fas-FasL, causing hepatic injury that can eventually proceed to cirrhosis and end-stage liver disease. Here we report that the hepatocyte growth factor receptor, Met, plays an important part in preventing Fas-mediated apoptosis of hepatocytes by sequestering Fas. We also show that Fas antagonism by Met is abrogated in human fatty liver disease (FLD). Through structure-function studies, we found that a YLGA amino-acid motif located near the extracellular N terminus of the Met α-subunit is necessary and sufficient to specifically bind the extracellular portion of Fas and to act as a potent FasL antagonist and inhibitor of Fas trimerization. Using mouse models of FLD, we show that synthetic YLGA peptide tempers hepatocyte apoptosis and liver damage and therefore has therapeutic potential.
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