Alternative proteolytic processing of hepatocyte growth factor during wound repair

N Buchstein, D Hoffmann, H Smola, S Lang… - The American journal of …, 2009 - Elsevier
N Buchstein, D Hoffmann, H Smola, S Lang, M Paulsson, C Niemann, T Krieg, SA Eming
The American journal of pathology, 2009Elsevier
Wound healing is a crucial regenerative process in all organisms. We examined expression,
integrity, and function of the proteins in the hepatocyte growth factor (HGF)/c-Met signaling
pathway in normally healing and non-healing human skin wounds. Whereas in normally
healing wounds phosphorylation of c-Met was most prominent in keratinocytes and dermal
cells, in non-healing wounds phosphorylation of c-Met was barely detectable, suggesting
reduced c-Met activation. In wound exudates obtained from non-healing, but not from …
Wound healing is a crucial regenerative process in all organisms. We examined expression, integrity, and function of the proteins in the hepatocyte growth factor (HGF)/c-Met signaling pathway in normally healing and non-healing human skin wounds. Whereas in normally healing wounds phosphorylation of c-Met was most prominent in keratinocytes and dermal cells, in non-healing wounds phosphorylation of c-Met was barely detectable, suggesting reduced c-Met activation. In wound exudates obtained from non-healing, but not from healing wounds, HGF protein was a target of substantial proteolytic processing that was different from the classical activation by known serine proteases. Western blot analysis and protease inhibitor studies revealed that HGF is a target of neutrophil elastase and plasma kallikrein during skin repair. Proteolytic processing of HGF by each of these proteases significantly attenuated keratinocyte proliferation, wound closure capacity in vitro, and c-Met signal transduction. Our findings reveal a novel pathway of HGF processing during skin repair. Conditions in which proteases are imbalanced and tend toward increased proteolytic activity, as in chronic non-healing wounds, might therefore compromise HGF activity due to the inactivation of the HGF protein and/or the generation of HGF fragments that ultimately mediate a dominant negative effect and limit c-Met activation.
Elsevier