Novel mechanism of hepatocyte growth factor against prevention of inflammation and oxidative stress

Hepatocyte growth factor (HGF) was originally identified as a potent mitogen stimulating hepa- tocyte growth. It also has mesenchyme-derived pleiotropic effects of regulating growth, motility, and morphogenesis of various types of cells, and is thus considered a humoral mediator of morphogenic tissue interactions. The protective effects of HGF against oxidative stress are im- portant in the early stage of inflammation. Many studies suggest that epidermal growth factor receptor (EGFR) plays an important role in the production of oxidative stress. Some substances such as lipopolysaccharide (LPS) increase EGFR expression. LPS triggers sepsis shock and the systemic inflammatory response syndrome, which results in multiple organ failure. Recent reports demonstrated that HGF attenuated LPS- or angiotensin II (Ang II)-induced oxidative stress via EGFR degradation, and protected against vascular damage. Similarly, HGF inhibited the in- crease in expression of vascular cell adhesion molecule-1 in pathological conditions attributed LPS or Ang II. The protective effects of HGF are associated with the HGF/c-Met system. Since the HGF/c-Met system inhibits the translocation of SHIP2 to EGFR in pathological conditions, EGFR degradation is triggered via EGFR ubiquitination through SHIP2 binding to its own receptor, c- Met. This newly described mechanism of HGF to regulate SHIP2 recruitment to EGFR and inhibit LPS-induced inflammation via EGFR degradation may be useful for the development of anti- inflammatory agents.