| 17935821 |
Miura K, Yoshino R, Hirai Y, Goto T, Ohshima S, Mikami K, Yoneyama K, Watanabe D, Sato M, Senoo H, Kodama Y, Osawa Y, Brenner DA, Watanabe S: Epimorphin, a morphogenic protein, induces proteases in rodent hepatocytes through NF-kappaB. J Hepatol. 2007 Dec;47(6):834-43. Epub 2007 Sep 25.
BACKGROUND/AIMS: Epimorphin, expressed by hepatic stellate cells in the liver, directs normal morphogenesis in various organs. The aim of this study was to clarify the mechanism by which epimorphin functions as a morphogen in vitro. METHODS: Male Balb/c mice and Sprague-Dawley rats were used. First, we explored the relationship between epimorphin expression and distribution of protease-positive cells in carbon tetrachloride-induced acute liver injury. We then examined protease levels in cultured hepatocytes and signal transduction of epimorphin. Finally, we determined the requirement for proteases and NF-kappaB in spheroid formation induced by epimorphin. RESULTS: Epimorphin expression was enhanced in injured areas during late recovery phase, in which protease-positive hepatocytes were localized adjacent to epimorphin-expressing cells. In vitro, epimorphin induced matrix metalloproteinase (MMP) 9, MMP 3 and urokinase type plasminogen activator (uPA) in hepatocytes. NF-kappaB mediated these protease expressions in hepatocytes. These proteases were required for epimorphin-induced and Matrigel induced spheroid. An epimorphin-neutralizing antibody also blocked spheroid formation on Matrigel, which contained epimorphin. In addition, NF-kappaB activation was also required for spheroid formation. CONCLUSION: Epimorphin elicits hepatocyte spheroids by inducing proteases in rodent hepatocytes through NF-kappaB. |
16(0,0,1,11) |