Focal enhancement of expression of c-Met/hepatocyte growth factor receptor in the myocardium in human myocardial infarction

To determine the distribution and expression level of hepatocyte growth factor (HGF) specific receptor, c-Met, in human myocardial infarction. Autopsies of 13 patients who died without heart diseases (control) and 13 patients with a history of myocardial infarction (2 h to 10 years before death). The harvested myocardial tissues were stained with hematoxylin–eosin (H&E) and immunohistochemically stained for c-Met expression by the avidin–biotin–horseradish peroxidase complex method using an antibody to c-Met. C-Met expression was only slightly increased in control subjects and in noninfarcted myocardium of the test group. In contrast, high expression was noted in the peripheral region of the myocardial infarction and in some hypertrophic myocardial cells. C-Met was not expressed in the infarcted myocardium, but overexpression was noted in the surrounding myocardial cells of blood vessels and in the subendocardium and subepicardium in a band-like pattern. The expression level of c-Met was most enhanced at the time of appearance of coagulative necrosis and least in the myocardium of subjects with old infarcts. Our results indicate that HGF preferentially reaches the ischemic regions of the myocardium and has local and direct effects on the myocardium in patients with myocardial infarction.