Sustained endoplasmic reticulum stress inhibits hepatocyte proliferation via downregulation of c-Met expression
- 423 Downloads
The molecular mechanisms of impaired liver regeneration in several liver diseases remain poorly understood. Endoplasmic reticulum (ER) stress has been observed in a variety of liver diseases. The aims of this study were to explore the impacts of ER stress on hepatocyte growth factor (HGF)-induced proliferation and c-Met expression in human hepatocyte L02 cells. Human hepatocyte L02 cells were incubated with thapsigargin (TG) to induce ER stress. 4-Phenylbutyric acid (PBA) was used to rescue ER stress. Activation of glucose-regulated protein 78, phosphorylation of PKR-like ER kinase and eukaryotic translation initiation factor-2α, and the expression of c-Met were determined by western blotting. The expression of c-Met mRNA was observed by reverse transcription polymerase chain reaction. L02 cell proliferation was determined by the MTS assay. L02 cell proliferation was significantly impaired in TG-treated L02 cells from 24 to 48 h, while PBA partly restored the proliferation of L02 cells. In addition, TG treatment significantly decreased the sensitivity of L02 cells to HGF-induced proliferation. PBA partly resumed the sensitivity of L02 cells to HGF-induced proliferation. The expression of c-Met protein in L02 cells was downregulated from 6 h after TG treatment, and PBA partly restored c-Met expression inhibited by TG. The expression of c-Met mRNA was also significantly downregulated from 24 to 48 h after TG treatment. Our results strongly suggest that sustained ER stress inhibits hepatocyte proliferation via downregulation of both c-Met mRNA and protein expression in human hepatocyte L02 cells.
KeywordsHepatocyte Hepatocyte growth factor Proliferation Endoplasmic reticulum stress c-Met
This work was partially supported by the Funds of the Chinese National Natural Science Foundation Project (81160067/H0318).
- 7.Kamohara Y, Sugiyama N, Mizuguchi T, Inderbitzin D, Lilja H, Middleton Y, Neuman T, Demetriou AA, Rozga J (2000) Inhibition of signal transducer and activator transcription factor 3 in rats with acute hepatic failure. Biochem Biophys Res Commun 273:129–135. doi: 10.1006/bbrc.2000.2881 PubMedCrossRefGoogle Scholar
- 16.D’Errico A, Fiorentino M, Ponzetto A, Daikuhara Y, Tsubouchi H, Brechot C, Scoazec J, Grigioni WF (1996) Liver hepatocyte growth factor does not always correlate with hepatocellular proliferation in human liver lesions: its specific receptor c-met does. Hepatology 24:60–64. doi: 10.1002/hep.510240112 PubMedGoogle Scholar
- 18.Ido A, Moriuchi A, Numata M, Murayama T, Teramukai S, Marusawa H, Yamaji N, Setoyama H, Kim ID, Chiba T, Higuchi S, Yokode M, Fukushima M, Shimizu A, Tsubouchi H (2011) Safety and pharmacokinetics of recombinant human hepatocyte growth factor (rh-HGF) in patients with fulminant hepatitis: a phase I/II clinical trial, following preclinical studies to ensure safety. J Transl Med 9:55. doi: 10.1186/1479-5876-9-55 PubMedCentralPubMedCrossRefGoogle Scholar
- 19.Marquardt JU, Seo D, Gomez-Quiroz LE, Uchida K, Gillen MC, Kitade M, Kaposi-Novak P, Conner EA, Factor VM, Thorgeirsson SS (2012) Loss of c-Met accelerates development of liver fibrosis in response to CCl4 exposure through deregulation of multiple molecular pathways. Biochim Biophys Acta 1822:942–951. doi: 10.1016/j.bbadis.2012.02.012 PubMedCentralPubMedCrossRefGoogle Scholar
- 21.Giebeler A, Boekschoten MV, Klein C, Borowiak M, Birchmeier C, Gassler N, Wasmuth HE, Müller M, Trautwein C, Streetz KL (2009) c-Met confers protection against chronic liver tissue damage and fibrosis progression after bile duct ligation in mice. Gastroenterology 137(297–308):e4. doi: 10.1053/j.gastro.2009.01.068 Google Scholar
- 30.Asselah T, Bièche I, Mansouri A, Laurendeau I, Cazals-Hatem D, Feldmann G, Bedossa P, Paradis V, Martinot-Peignoux M, Lebrec D, Guichard C, Ogier-Denis E, Vidaud M, Tellier Z, Soumelis V, Marcellin P, Moreau R (2010) In vivo hepatic endoplasmic reticulum stress in patients with chronic hepatitis C. J Pathol 221:264–274. doi: 10.1002/path.2703 PubMedCrossRefGoogle Scholar
- 32.Li CY, Cao CZ, Xu WX, Cao MM, Yang F, Dong L, Yu M, Zhan YQ, Gao YB, Li W, Wang ZD, Ge CH, Wang QM, Peng RY, Yang XM (2010) Recombinant human hepassocin stimulates proliferation of hepatocytes in vivo and improves survival in rats with fulminant hepatic failure. Gut 59:817–826. doi: 10.1136/gut.2008.171124 PubMedCrossRefGoogle Scholar
- 37.Saito A, Ochiai K, Kondo S, Tsumagari K, Murakami T, Cavener DR, Imaizumi K (2011) Endoplasmic reticulum stress response mediated by the PERK-eIF2a-ATF4 pathway is involved in osteoblast differentiation induced by BMP2. J Biol Chem 286:4809–4818. doi: 10.1074/jbc.M110.152900 PubMedCentralPubMedCrossRefGoogle Scholar
- 46.Cao M–M, Xu WX, Li CY, Cao CZ, Wang ZD, Yao JW, Yu M, Zhan YQ, Wang XH, Tang LJ, Chen H, Li W, Ge CH, Yang XM (2011) Hepassocin regulates cell proliferation of the human hepatic cells L02 and hepatocarcinoma cells through different mechanisms. J Cell Biochem 112:2882–2890. doi: 10.1002/jcb.23202 PubMedCrossRefGoogle Scholar