김 (Porphyra yezoensis) peptide에 의한 IEC-6 세포 증식 작용 메커니즘

Abstract

Porphyra yezoensis is a genus of marine red algae and has potential biological activities. Porphyra yezoensis mainly contains about 40-45% carbohydrates, 25-50% proteins and 20-40% polysaccharides, lipids and some vitamins. Also, Porphyra yezoensis has been extensively studied because of its many biological properties including anti-viral, anti-ulcer, anti-inflammatory and anti-tumor activities. In this study, peptide of Porphyra yezoensis (PY-PE) was determined which had a proliferative effect, and examined signal transduction pathways focusing on insulin-like growth factor-I receptor (IGF-IR), epidermal growth factor receptor (EGFR) signaling pathways. IEC-6 cells were incubated in serum-free medium with various concentrations of PY-PE (0, 125, 250, 500, 1000 ng/ml). Using the MTS assays, we obtained PY-PE induced cell proliferation in a dose-dependent manner. The IGF-IR and EGFR system plays essential role in the regulation of cell growth, proliferation and survival. PY-PE induced the increased expression of IGF-IR and EGFR. IGF-IR and EGFR induced activation of multiple intracellular signal transduction cascades, including the phosphatidylinositol 3-kinase (PI3K)-Akt pathway, the mitogen-activated protein kinase (MAPK) pathway and the Ras signaling pathway. Also we observed that cell cycle analysis and expression of cell cycle related proteins. This result through where cell proliferation has occurred and there has increased G1 percent and increase in expression of cyclin D, cyclin E, Cdk2, Cdk4, Cdk6 and decrease in protein levels of p21, p27. Activator protein-1 (AP-1) regulates cell proliferation and survival responses. The present study examined the effects of PY-PE on the AP-1 signaling pathway. AP-1 protein in the nuclear fraction was increased by PY-PE treatment. These results have important implications for understanding the role of cell proliferation signaling pathway in intestinal epithelial cell. Therefore, PY-PE could be a potential source of bio-functional food to have cell proliferation effect in intestinal epithelial cell.