title: A peptide from Porphyra yezoensis stimulates the proliferation of IEC-6 cells by activating the insulin-like growth factor I receptor signaling pathway.
abstract: Porphyra yezoensis (P. yezoensis) is the most noteworthy red alga and is mainly consumed in China, Japan and Korea. In the present study, the effects of a P. yezoensis peptide (PY‑PE) on cell proliferation and the associated signaling pathways were examined in IEC‑6 rat intestinal epithelial cells. First, the MTS assay showed that PY‑PE induced cell proliferation in a dose‑dependent manner. Subsequently, the mechanism behind the proliferative activity induced by PY‑PE was determined. The insulin‑like growth factor‑I receptor (IGF‑IR) signaling pathway was the main focus as it plays an important role in the regulation of cell growth and proliferation. PY‑PE increased the protein and mRNA expression of IGF‑IR, insulin receptor substrate‑1, Shc and PY‑99. In addition, PY‑PE stimulated extracellular signal‑regulated kinase phosphorylation and phosphatidylinositol 3‑kinase/Akt activation but inhibited p38 and c‑Jun N‑terminal kinase phosphorylation. Furthermore, PY‑PE treatment increased protein and mRNA expression levels of activator protein‑1, which regulates cell proliferation and survival, in the nuclear fraction. These results have significant implications for understanding the role of cell proliferation signaling pathways in intestinal epithelial cells.
authors.affiliation: Department of Food Science and Nutrition, Pukyong National University, Busan 608‑737, Republic of Korea.
authors.forename: Min-Kyeong
authors.initials: MK
authors.lastname: Lee
authors.affiliation: Institute of Fisheries Science, Pukyong National University, Busan 619‑911, Republic of Korea.
authors.forename: In-Hye
authors.initials: IH
authors.lastname: Kim
authors.affiliation: Institute of Fisheries Science, Pukyong National University, Busan 619‑911, Republic of Korea.
authors.forename: Youn-Hee
authors.initials: YH
authors.lastname: Choi
authors.affiliation: Department of Food Science and Nutrition, Pukyong National University, Busan 608‑737, Republic of Korea.
authors.forename: Taek-Jeong
authors.initials: TJ
authors.lastname: Nam
mesh_terms: D000818:Animals; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects; D007413:Intestinal Mucosa / Q000166:cytology / Q000378:metabolism*; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology*; D010940:Plant Proteins / Q000737:chemistry / Q000494:pharmacology*; D044664:Porphyra / Q000737:chemistry*; D051381:Rats; D017451:Receptors, Somatomedin / Q000096:biosynthesis*; D015398:Signal Transduction / Q000187:drug effects*
chemical_list: D010455:Peptides; D010940:Plant Proteins; D017451:Receptors, Somatomedin