title: Glycoprotein extraction from Laminaria japonica promotes IEC-6 cell proliferation.
abstract: The brown alga Laminaria japonica is frequently consumed in Korea, Japan and China, and has been used for more than a thousand years as a drug in traditional Chinese medicine. In this study, we isolated a novel glycoprotein from L. japonica that stimulates the growth of the IEC-6 normal murine intestinal epithelial cells. We also identified the mechanism by which this glycoprotein, referred to as LJGP, stimulates cell growth. After 24 h of exposure to LJGP, cell proliferation increased in a dose-dependent manner. To further explore the mechanism associated with LJGP-induced cell proliferation, we treated cells for various times with LJGP. We focused on the epidermal growth factor receptor (EGFR) signaling pathway, which is involved in the regulation of cellular proliferation and differentiation, during LJGP-induced cell growth. The results showed that LJGP induced EGFR and Akt activation. Furthermore, LJGP stimulated Shc/Grb2 binding and ERK activation, but inhibited JNK phosphorylation. These results indicate that LJGP stimulates gastrointestinal cell growth by activating the EGFR signaling pathway.
authors.affiliation: Faculty of Food Science and Biotechnology, Pukyong National University 599-1, Pusan 608-737, Republic of Korea.
authors.forename: Hiroe
authors.initials: H
authors.lastname: Go
authors.forename: Hye-Jung
authors.initials: HJ
authors.lastname: Hwang
authors.forename: Taek-Jeong
authors.initials: TJ
authors.lastname: Nam
mesh_terms: D020418:Algal Proteins / Q000737:chemistry / Q000494:pharmacology*; D000704:Analysis of Variance; D000818:Animals; D048708:Cell Growth Processes / Q000187:drug effects; D002460:Cell Line; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D066246:ErbB Receptors / Q000378:metabolism; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D006023:Glycoproteins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D007421:Intestine, Small / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D007795:Laminaria / Q000737:chemistry*; D051379:Mice; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010766:Phosphorylation; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D014443:Tyrosine / Q000378:metabolism
chemical_list: D020418:Algal Proteins; D006023:Glycoproteins; D014443:Tyrosine; D019869:Phosphatidylinositol 3-Kinases; C541485:EGFR protein, mouse; D066246:ErbB Receptors; D051057:Proto-Oncogene Proteins c-akt; D048049:Extracellular Signal-Regulated MAP Kinases